WorldWideScience

Sample records for cf-252 brachytherapy source

  1. The status of low dose rate and future of high dose rate Cf-252 brachytherapy

    International Nuclear Information System (INIS)

    Rivard, M.J.; Wierzbicki, J.G.; Van den Heuvel, F.; Chuba, P.J.; Fontanesi, J.

    1997-12-01

    This work describes the current status of the US low dose rate (LDR) Cf-252 brachytherapy program. The efforts undertaken towards development of a high dose rate (HDR) remotely after loaded Cf-252 source, which can accommodate 1 mg or greater Cf-252, are also described. This HDR effort is a collaboration between Oak Ridge National Laboratory (ORNL), commercial remote after loader manufactures, the Gershenson Radiation Oncology Center (ROC), and Wayne State University. To achieve this goal, several advances in isotope chemistry and source preparation at ORNL must be achieved to yield a specific material source loading of greater than or equal 1 mg Cf-252 per mm3. Development work with both radioactive and non-radioactive stand-ins for Cf-252 have indicated the feasibility of fabricating such sources. As a result, the decreased catheter diameter and computer controlled source placement will permit additional sites (e.g. brain, breast, prostate, lung, parotid, etc.) to be treated effectively with Cf-252 sources. Additional work at the Radiochemical Engineering and Development Center (REDC) remains in source fabrication, after loader modification, and safe design. The current LDR Cf-252 Treatment Suite at the ROC is shielded and licensed to hold up to 1 mg of Cf-252. This was designed to maintain cumulative personnel exposure, both external to the room and in direct isotope handling, at less than 20 microSv/hr. However, cumulative exposure may be greatly decreased if a Cf-252 HDR unit is employed which would eliminate direct isotope handling and decrease treatment times from tilde 3 hours to an expected range of 3 to 15 minutes. Such a Cf-252 HDR source will also demonstrate improved dose distributions over current LDR treatments due to the ability to step the point-like source throughout the target volume and weight the dwell time accordingly

  2. Importance of the neutrons kerma coefficient in the planning of Brachytherapy treatments with Cf-252 sources

    International Nuclear Information System (INIS)

    Paredes G, L.; Balcazar G, M.; Azorin N, J.; Francois L, J.L.

    2006-01-01

    The Cf-252 is a fast neutrons emitting radioisotope by spontaneous fission that can be used as sealed source in medicine applications, industry and research. Commercially its offer sources of different sizes, compact and with a fast neutrons emission of the order of 10 6 n/s-μg and an energy spectra that presents respectively maxim and average energy in 2.1 MeV and 0.7 MeV. In medicine new applications are being developed for the treatment of patient with hypoxic and voluminous tumors, where the therapy with photons has not given positive results, as well as for the protocols of therapy treatment by boron neutron capture, where very small sources of Cf-252 will be used with the interstitial brachytherapy technique of high and low dose rate. In this work an analysis of how the small differences that exist in the elementary composition of 4 wicked tumors, 4 ICRU healthy tissues and 3 substitute materials of ICRU tissue used in dosimetry are presented, its generate changes in the neutrons kerma coefficient in function of the energy and consequently in the absorbed dose in the interval of 11 eV to 29 MeV. These differences can produce maximum variations of the neutron kerma coefficients ratio for E n > 1 keV of the one: 15% tumor/ICRU guest healthy tissue, 12% ICRU tumor/muscle, 12% ICRU healthy tissues ICRU/ICRU muscle, 22% substitutes tissue/tumor and 22% ICRU substitutes tissue/muscle. Also, it was found that the average value of the neutrons kerma coefficient for the 4 wicked tumors is from 6% to 7% smaller that the average value for the soft tissue in the interval energy of interest for therapy with fast neutrons with E n > 1 MeV. These results have a special importance during the planning process of brachytherapy treatments with sources of 252 Cf, to optimize and to individualize the patients treatments. (Author)

  3. Comparative dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Samia de Freitas, E-mail: samiabrandao@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Campos, Tarcisio Passos Ribeiro de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2013-06-15

    Objective: comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and methods: simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted into biologically weighted dose rates. Results: intracavitary balloon catheter brachytherapy with I-125 produced biologically weighted mean dose rates of 3.2E-11, 1.3E-10, 1.9E-11 and 6.9E-13 RBE.Gy.h{sup -1}.p{sup -1}.s, respectively, on the healthy tissue, on the balloon periphery and on the /{sub 1} and /{sub 2} tumor infiltration zones. On the other hand, Cf-252 brachytherapy combined with BNCT produced a biologically weighted mean dose rate of 5.2E-09, 2.3E-07, 8.7E-09 and 2.4E-09 RBE.Gy.h{sup -1}.p{sup -1}.s, respectively on the healthy tissue, on the target tumor and on the /{sub 1} and /{sub 2} infiltration zones. Conclusion: Cf-252 brachytherapy combined with BNCT delivered a selective irradiation to the target tumor and to infiltration zones, while intracavitary balloon catheter brachytherapy with I-125 delivered negligible doses on the tumor infiltration zones. (author)

  4. Comparative dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for brain tumors

    Directory of Open Access Journals (Sweden)

    Samia de Freitas Brandao

    2013-07-01

    Full Text Available Objective Comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and Methods Simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted into biologically weighted dose rates. Results Intracavitary balloon catheter brachytherapy with I-125 produced biologically weighted mean dose rates of 3.2E-11, 1.3E-10, 1.9E-11 and 6.9E-13 RBE.Gy.h-1.p-1.s, respectively, on the healthy tissue, on the balloon periphery and on the I 1 and I 2 tumor infiltration zones. On the other hand, Cf-252 brachytherapy combined with BNCT produced a biologically weighted mean dose rate of 5.2E-09, 2.3E-07, 8.7E-09 and 2.4E-09 RBE.Gy.h-1.p-1.s, respectively on the healthy tissue, on the target tumor and on the I 1 and I 2 infiltration zones. Conclusion Cf-252 brachytherapy combined with BNCT delivered a selective irradiation to the target tumor and to infiltration zones, while intracavitary balloon catheter brachytherapy with I-125 delivered negligible doses on the tumor infiltration zones.

  5. Dosimetric analysis of BNCT - Boron Neutron Capture Therapy - coupled to 252Cf brachytherapy

    International Nuclear Information System (INIS)

    Brandao, Samia F.; Campos, Tarcisio P.R.

    2009-01-01

    The incidence of brain tumors is increasing in world population; however, the treatments employed in this type of tumor have a high rate of failure and in some cases have been considered palliative, depending on histology and staging of tumor. Its necessary to achieve the control tumor dose without the spread irradiation cause damage in the brain, affecting patient neurological function. Stereotactic radiosurgery is a technique that achieves this; nevertheless, other techniques that can be used on the brain tumor control must be developed, in order to guarantee lower dose on health surroundings tissues other techniques must be developing. The 252 Cf brachytherapy applied to brain tumors has already been suggested, showing promising results in comparison to photon source, since the active source is placed into the tumor, providing greater dose deposition, while more distant regions are spared. BNCT - Boron Neutron Capture Therapy - is another technique that is in developing to brain tumors control, showing theoretical superiority on the rules of conventional treatments, due to a selective irradiation of neoplasics cells, after the patient receives a borate compound infusion and be subjected to a epithermal neutrons beam. This work presents dosimetric studies of the coupling techniques: BNCT with 252 Cf brachytherapy, conducted through computer simulation in MCNP5 code, using a precise and well discretized voxel model of human head, which was incorporated a representative Glioblastoma Multiform tumor. The dosimetric results from MCNP5 code were exported to SISCODES program, which generated isodose curves representing absorbed dose rate in the brain. Isodose curves, neutron fluency, and dose components from BNCT and 252 Cf brachytherapy are presented in this paper. (author)

  6. Cf-252 neutron brachytherapy: an advance for bulky localized cancer therapy

    International Nuclear Information System (INIS)

    Maruyama, Y.

    1984-01-01

    The physical and radiobiogical basis as well as the rationale for neutron brachytherapy, using Cf-252, in human cancer therapy is reviewed. Cf-252 brachytherapy represents an economical and effective form of neutron radiotherapy that is readily and safely applied clinically. It can be used anywhere in the world without unusual personnel, equipment or facilities, or prohibitive expenses or maintenance costs. Used on bulky head and neck, thoracic, abdominal, pelvic, brain and appendage cancers, it overcomes hypoxic radioresistance and produces remarkable rates of tumor clearance. It is easily combined with photon radiotherapy and in proper schedules and doses, it can control advanced but still localized regional cancers to produce tumor cure. It will clear the local manifestations of recurrent or metastatic tumors or advanced stages of primary tumors and therefore in conjunction with other adjuvant therapies offers much more effective tumor control and palliation than present conventional therapy. (Auth.)

  7. Brachytherapy of carcinoma of vulva with 252Cf

    International Nuclear Information System (INIS)

    Spikalovas, V.; Sinkevicius, V.; Drulia, E.; Kurtinaitis, J.

    1996-01-01

    Thirty patients with carcinoma of vulva were treated with interstitial neutron radiotherapy with 252 Cf. Age of patients was from 32 to 83 years. Stage I was in I patient, stage II - in 12, stage III was in 10 patients. The diagnosis of vulvar cancer was made for the first time in 11 cases, 19 patients had recurrences after the initial treatment. Most of these patients also received external irradiation for cancer of vulva and bilateral inguinal sites with a single fraction dose of 2 Gy to a total dose 30-50 Gy. Enlarged inguinal lymph nodes were irradiated additionally to 60 Gy with reduced field of irradiation. When radiotherapy was used repeatedly interstitial brachytherapy comprised the major part of irradiation dose or the therapy was used alone delivering 35-55 iGy. We used 252 Cf sources with increased activity at the ends 20-30 mm long. A number of inserted sources varied from 2 to 10, irradiation dose rate from 20.3 to 236.7 cGy/h, time of irradiation from 10.2 to 12. hours, RBE from 4.6 to 6.33. Special template device made it possible to implant sources in strictly pre-set geometry. Analysis of survival of patients showed that 2 years survival was 66%, 3 years - 60%, and 5 years survival was 49%. In two cases necrotic epithelitis developed with following radiation ulcer which were cured in 3-4 months. Clinical data showed great effectiveness of interstitial neutron therapy having in mind that 19 patients were treated for recurrences of vulvar cancer after previuos treatment

  8. A Monte Carlo Study on the Effect of Various Neutron Capturers on Dose Distribution in Brachytherapy with 252Cf Source

    Directory of Open Access Journals (Sweden)

    Firoozabadi M. M.

    2017-03-01

    Full Text Available Background: In neutron interaction with matter and reduction of neutron energy due to multiple scatterings to the thermal energy range, increasing the probability of thermal neutron capture by neutron captures makes dose enhancement in the tumors loaded with these materials. Objective: The purpose of this study is to evaluate dose distribution in the presence of 10B, 157Gd and 33S neutron capturers and to determine the effect of these materials on dose enhancement rate for 252Cf brachytherapy source. Methods: Neutron-ray flux and energy spectra, neutron and gamma dose rates and dose enhancement factor (DEF are determined in the absence and presence of 10B, 157Gd and 33S using Monte Carlo simulation. Results: The difference in the thermal neutron flux rate in the presence of 10B and 157Gd is significant, while the flux changes in the fast and epithermal energy ranges are insensible. The dose enhancement factor has increased with increasing distance from the source and reached its maximum amount equal to 258.3 and 476.1 cGy/h/µg for 157Gd and 10B, respectively at about 8 cm distance from the source center. DEF for 33S is equal to one. Conclusion: Results show that the magnitude of dose augmentation in tumors containing 10B and 157Gd in brachytherapy with 252Cf source will depend not only on the capture product dose level, but also on the tumor distance from the source. 33S makes dose enhancement under specific conditions that these conditions depend on the neutron energy spectra of source, the 33S concentration in tumor and tumor distance from the source.

  9. Importance of the neutrons kerma coefficient in the planning of Brachytherapy treatments with Cf-252 sources; Importancia del coeficiente de kerma de neutrones en la planeacion de tratamientos de Braquiterapia con fuentes de Cf-252

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.; Balcazar G, M. [ININ, 52045 Ocoyocac, Estado de Mexico (Mexico); Azorin N, J. [Universidad Autonoma Metropolitana, 09000 Mexico D.F. (Mexico); Francois L, J.L. [UNAM, 04500 Mexico D.F. (Mexico)]. e-mail: lpg@nuclear.inin.mx

    2006-07-01

    The Cf-252 is a fast neutrons emitting radioisotope by spontaneous fission that can be used as sealed source in medicine applications, industry and research. Commercially its offer sources of different sizes, compact and with a fast neutrons emission of the order of 10{sup 6} n/s-{mu}g and an energy spectra that presents respectively maxim and average energy in 2.1 MeV and 0.7 MeV. In medicine new applications are being developed for the treatment of patient with hypoxic and voluminous tumors, where the therapy with photons has not given positive results, as well as for the protocols of therapy treatment by boron neutron capture, where very small sources of Cf-252 will be used with the interstitial brachytherapy technique of high and low dose rate. In this work an analysis of how the small differences that exist in the elementary composition of 4 wicked tumors, 4 ICRU healthy tissues and 3 substitute materials of ICRU tissue used in dosimetry are presented, its generate changes in the neutrons kerma coefficient in function of the energy and consequently in the absorbed dose in the interval of 11 eV to 29 MeV. These differences can produce maximum variations of the neutron kerma coefficients ratio for E{sub n} > 1 keV of the one: 15% tumor/ICRU guest healthy tissue, 12% ICRU tumor/muscle, 12% ICRU healthy tissues ICRU/ICRU muscle, 22% substitutes tissue/tumor and 22% ICRU substitutes tissue/muscle. Also, it was found that the average value of the neutrons kerma coefficient for the 4 wicked tumors is from 6% to 7% smaller that the average value for the soft tissue in the interval energy of interest for therapy with fast neutrons with E{sub n} > 1 MeV. These results have a special importance during the planning process of brachytherapy treatments with sources of {sup 252}Cf, to optimize and to individualize the patients treatments. (Author)

  10. Graphite moderated 252Cf source

    International Nuclear Information System (INIS)

    Sajo B, L.; Barros, H.; Greaves, E. D.; Vega C, H. R.

    2014-08-01

    The thorium molten salt reactor is an attractive and affordable nuclear power option for developing countries with insufficient infrastructure and limited technological capability. In the aim of personnel training and experience gathering at the Universidad Simon Bolivar there is in progress a project of developing a subcritical thorium liquid fuel reactor. The neutron source to run this subcritical reactor is a 252 Cf source and the reactor will use high-purity graphite as moderator. Using the MCNP5 code the neutron spectra of the 252 Cf in the center of the graphite moderator has been estimated along the channel where the liquid thorium salt will be inserted; also the ambient dose equivalent due to the source has been determined around the moderator. (Author)

  11. Calculated neutron air kerma strength conversion factors for a generically encapsulated Cf-252 brachytherapy source

    CERN Document Server

    Rivard, M J; D'Errico, F; Tsai, J S; Ulin, K; Engler, M J

    2002-01-01

    The sup 2 sup 5 sup 2 Cf neutron air kerma strength conversion factor (S sub K sub N /m sub C sub f) is a parameter needed to convert the radionuclide mass (mu g) provided by Oak Ridge National Laboratory into neutron air kerma strength required by modern clinical brachytherapy dosimetry formalisms indicated by Task Group No. 43 of the American Association of Physicists in Medicine (AAPM). The impact of currently used or proposed encapsulating materials for sup 2 sup 5 sup 2 Cf brachytherapy sources (Pt/Ir-10%, 316L stainless steel, nitinol, and Zircaloy-2) on S sub K sub N /m sub C sub f was calculated and results were fit to linear equations. Only for substantial encapsulation thicknesses, did S sub K sub N /m sub C sub f decrease, while the impact of source encapsulation composition is increasingly negligible as Z increases. These findings are explained on the basis of the non-relativistic kinematics governing the majority of sup 2 sup 5 sup 2 Cf neutron interactions. Neutron kerma and energy spectra resul...

  12. System control for the modulated 252Cf source ''Shuffler''

    International Nuclear Information System (INIS)

    Stephens, M.M.

    1975-06-01

    The design and theory of operation of the control chassis for a 252 Cf nondestructive assay system are described. This system repetitively transfers a 252 Cf source from the irradiation region to a shielded position before measuring the delayed neutrons. The design criteria for the system were: rapid movement and precise positioning of the 252 Cf source, precise positioning of the sample, and very accurate timing of the irradiate and count cycles. To achieve these results crystal oscillators were used for timing, and stepping motors were used to position the sample and the source. (U.S.)

  13. Graphite moderated {sup 252}Cf source

    Energy Technology Data Exchange (ETDEWEB)

    Sajo B, L.; Barros, H.; Greaves, E. D. [Universidad Simon Bolivar, Nuclear Physics Laboratory, Apdo. 89000, 1080A Caracas (Venezuela, Bolivarian Republic of); Vega C, H. R., E-mail: fermineutron@yahoo.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-08-15

    The thorium molten salt reactor is an attractive and affordable nuclear power option for developing countries with insufficient infrastructure and limited technological capability. In the aim of personnel training and experience gathering at the Universidad Simon Bolivar there is in progress a project of developing a subcritical thorium liquid fuel reactor. The neutron source to run this subcritical reactor is a {sup 252}Cf source and the reactor will use high-purity graphite as moderator. Using the MCNP5 code the neutron spectra of the {sup 252}Cf in the center of the graphite moderator has been estimated along the channel where the liquid thorium salt will be inserted; also the ambient dose equivalent due to the source has been determined around the moderator. (Author)

  14. Fast neutron therapy with high intensity Cf-252 sources by remotely controlled afterloading and clinical experiences in the treatment of gynaecological cancers

    International Nuclear Information System (INIS)

    Yamashita, H.; Hashimoto, S.; Wada, M.; Dokiya, T.

    1986-01-01

    Cf-252 fast neutron therapy with high intensity Cf-252 sources was tested for the treatment of advanced gynaecological cancers using a remotely controlled afterloading machine designed by the author and manufactured by Toshiba. Using high intensity sources and short treatment times in a special treatment room, personnel or environment exposure to radiation was at a safe level, i.e. almost nil. During 1978-1983 18 stage III cases of cancer of the uterine cervix were treated with complete response in 78% and 44% 5 year survivals. The types of acute and delayed effects of Cf-252 were the same as Co-60 or Cs-137 but the rectum was found sensitive in this system of brachytherapy. A dose of 1,000-1,500 cGy/6-10 F in 10-22 days of Cf-252 radiation was tolerated and produced tumor cure

  15. Viability of neutron brachytherapy technique using Cf252 for tumors of salivary glands therapy

    International Nuclear Information System (INIS)

    Andrade, Lidia M.; Campos, Tarcisio P.R.

    2000-01-01

    Gland salivary tumors, although uncommon, present significant characteristics such as distant metastasis, recurrence and average survive of five year for treated patients. Those tumors presents low response to a conventional radiotherapy, photon and electron therapy; thus, this modality is associated with surgery. Fast neutron therapy has been presented better results in controlling the local tumor in comparison with conventional radiotherapy. Brachytherapy with Cf-252 presents an alternative treatment for tumors. Those radiotherapy technique are discussed and analyzed. (author)

  16. Neutron Spectra, Fluence and Dose Rates from Bare and Moderated Cf-252 Sources

    Energy Technology Data Exchange (ETDEWEB)

    Radev, Radoslav P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-04-01

    A new, stronger 252Cf source (serial number SR-CF-3050-OR) was obtained from Oak Ridge National Laboratory (ORNL) in 2014 to supplement the existing 252Cf sources which had significantly decayed. A new instrument positioning track system was designed and installed by Hopewell Designs, Inc. in 2011. The neutron field from the new, stronger 252Cf source in the modified calibration environment needed to be characterized as well as the modified neutron fields produced by the new source and seven different neutron moderators. Comprehensive information about our 252Cf source, its origin, production, and isotopic content and decay characteristics needed to be compiled as well. This technical report is intended to address these issues.

  17. Metronidazole in the treatment of cervical cancer using Cf-252 neutron brachytherapy

    International Nuclear Information System (INIS)

    Maruyama, Y.

    1986-01-01

    Metronidazole was tested for its possible use in the Cf-252 brachytherapy of cervical cancer as a radiosensitizer and to deal with anaerobic pelvic infection. 15 patients were treated by only 14 were evaluable. All stages from stage IB-IVB were treated and complete local tumor regression was noted in all cases although it could take place very slowly. 5/14 (36%) are 1.5-3 year survivors but only among the patients with stage I-II disease. No unusual radio-enhancing action was observed but metronidazole appeared to be useful to treat the vaginal, cervix and uterine infections often associated with high stage disease and bulky, ulcerative or necrotic tumors

  18. Methods for Cf-252 cervix cancer therapy and treatment planning for GYN malignancies in Lexington

    International Nuclear Information System (INIS)

    Coffey, C.W.; Yoneda, J.; Beach, J.L.; Maruyama, Y.

    1986-01-01

    This paper presents the clinical physics methods and treatment planning techniques used in both the external beam and brachytherapy treatment of GYN malignancies in the Radiotherapy Department of the University of Kentucky Medical Center. Specific description of the departmental implant suite and brachytherapy procedures are included. The optimization of brachytherapy applicator placement, source arrangement, and normal and tumor total dose and dose distributions are presented. Quality assurance protocols for teletherapy and brachytherapy and patient and staff safety procedures with Cf-252 are discussed

  19. Neutron shielding for a 252 Cf source

    International Nuclear Information System (INIS)

    Vega C, H.R.; Manzanares A, E.; Hernandez D, V.M.; Eduardo Gallego, Alfredo Lorente

    2006-01-01

    To determine the neutron shielding features of water-extended polyester a Monte Carlo study was carried out. Materials with low atomic number are predominantly used for neutron shielding because these materials effectively attenuate neutrons, mainly through inelastic collisions and absorption reactions. During the selection of materials to design a neutron shield, prompt gamma production as well as radionuclide production induced by neutron activation must be considered. In this investigation the Monte Carlo method was used to evaluate the performance of a water-extended polyester shield designed for the transportation, storage, and use of a 252 Cf isotopic neutron source. During calculations a detailed model for the 252 Cf and the shield was utilized. To compare the shielding features of water extended polyester, the calculations were also made for the bare 252 Cf in vacuum, air and the shield filled with water. For all cases the calculated neutron spectra was utilized to determine the ambient equivalent neutron dose at four sites around the shielding. In the case of water extended polyester and water shielding the calculations were extended to include the prompt gamma rays produced during neutron interactions, with this information the Kerma in air was calculated at the same locations where the ambient equivalent neutron dose was determined. (Author)

  20. Characteristics of polyethylene-moderated 252Cf neutron sources

    International Nuclear Information System (INIS)

    Alejnikov, V.E.; Beskrovnaya, L.G.; Florko, B.V.

    2000-01-01

    Polyethylene-moderated 252 Cf neutron sources were designed to produce neutron reference fields' spectra that simulate the spectra observed in the workplaces within nuclear reactors and accelerators. The paper describes the neutron sources and fields. Neutron spectra were calculated by Monte Carlo method and compared with experimental data

  1. Californium Cf-252 for pelvic radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Y; Feola, J M; Tai, D; Wilson, L C; Van Nagell, J R; Yoneda, J

    1978-01-01

    Clinical data about therapy concerning tumors of the female gynecological cancers of the cervix, vagina and uterus are reviewed. Dosimetric, laboratory and radiobiological research data form the basis for an approach to such tumors using Cf-252 as a form of boost brachytherapy. Extreme personnel hazards are a real and important consideration and indicate that maximal containment and isolation procedures should be exercised in its use.

  2. Neutron shielding for a {sup 252} Cf source

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R.; Manzanares A, E.; Hernandez D, V.M. [Unidades Academicas de Estudios Nucleares e Ingenieria Electrica, Universidad Autonoma de Zacatecas, C. Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Eduardo Gallego, Alfredo Lorente [Depto. de Ingenieria Nuclear, ETS Ingenieros Industriales, Universidad Politecnica de Madrid, C. Jose Gutierrez Abascal 2, 28006 Madrid (Spain)]. e-mail: fermineutron@yahoo.com

    2006-07-01

    To determine the neutron shielding features of water-extended polyester a Monte Carlo study was carried out. Materials with low atomic number are predominantly used for neutron shielding because these materials effectively attenuate neutrons, mainly through inelastic collisions and absorption reactions. During the selection of materials to design a neutron shield, prompt gamma production as well as radionuclide production induced by neutron activation must be considered. In this investigation the Monte Carlo method was used to evaluate the performance of a water-extended polyester shield designed for the transportation, storage, and use of a {sup 252}Cf isotopic neutron source. During calculations a detailed model for the {sup 252}Cf and the shield was utilized. To compare the shielding features of water extended polyester, the calculations were also made for the bare {sup 252}Cf in vacuum, air and the shield filled with water. For all cases the calculated neutron spectra was utilized to determine the ambient equivalent neutron dose at four sites around the shielding. In the case of water extended polyester and water shielding the calculations were extended to include the prompt gamma rays produced during neutron interactions, with this information the Kerma in air was calculated at the same locations where the ambient equivalent neutron dose was determined. (Author)

  3. Effective source size as related to 252Cf neutron radiography

    International Nuclear Information System (INIS)

    Wada, Nobuo; Enomoto, Shigemasa; Tachikawa, Noboru; Nojiri, Toshiaki.

    1977-01-01

    The effective source size in 252 Cf thermal neutron radiography, relating to its geometrical unsharpness in image formation, is experimentally studied. A neutron radiographic system consists of a 160 μg 252 Cf neutron source, water moderator and divergent cadmium lined collimator. Thermal neutron image detection is performed with using a LiF scintillator and a high speed X-ray film to employ direct exposure method. The modulation transfer function, used for describing image quality, is derived from radiographic image corresponding to a cadmium plate with sharp edge. The modulation transfer function for the system is expressed by the product of the function for both geometrical and inherent unsharpness, and allows isolation of geometrical unsharpness as related to the effective size of the thermal neutron source. It is found to be 80 -- 90% of the collimator inlet diameter. (auth.)

  4. Implementation of 252Cf-source-driven power spectrum density measurement system

    International Nuclear Information System (INIS)

    Ren Yong; Wei Biao; Feng Peng; Li Jiansheng; Ye Cenming

    2012-01-01

    The principle of 252 Cf-source-driven power spectrum density measurement method is introduced. A measurement system and platform is realized accordingly, which is a combination of hardware and software, for measuring nuclear parameters. The detection method of neutron pulses based on an ultra-high-speed data acquisition card (three channels, 1 GHz sampling rate, 1 ns synchronization) is described, and the data processing process and the power spectrum density algorithm on PC are designed. This 252 Cf-source-driven power spectrum density measurement system can effectively obtain the nuclear tag parameters of nuclear random processes, such as correlation function and power spectrum density. (authors)

  5. A Phase I/II Protocol Using 252Cf for the Treatment of Cervical Carcinoma

    International Nuclear Information System (INIS)

    Anita Mahajan; Mark J. Rivard; Evelyn R. Nunez; David E. Wazer

    2000-01-01

    For this clinical study, external photon beam irradiation will be given in a standard fashion with intravenous cisplatinum (CDDP) every week as a radiosensitizing agent. We will incorporate 252 Cf as the brachytherapy source replacing 192 Ir, theoretically improving patient outcomes with its lack of cell cycle and oxygen dependence, and a therapeutic ratio possibly greater than unity. Local tumor control and control of systemic disease are potentially feasible using 252 Cf to initially debulk and destroy local bulky tumor with CDDP and X rays to enhance treatment efficacy and treat minimal microscopic and distant micrometastases. The initial 22 Cf dose will be 1 Gy per weekly fraction with 0.25-Gy increments toward a 2.5-Gy limit. Patients will be stratified according to their stage, toxicities and outcomes will be monitored closely, and the study will be halted if undo morbidities are noted

  6. Neutron activation analysis detection limits using 252Cf sources

    International Nuclear Information System (INIS)

    DiPrete, D.P.; Sigg, R.A.

    2000-01-01

    The Savannah River Technology Center (SRTC) developed a neutron activation analysis (NAA) facility several decades ago using low-flux 252 Cf neutron sources. Through this time, the facility has addressed areas of applied interest in managing the Savannah River Site (SRS). Some applications are unique because of the site's operating history and its chemical-processing facilities. Because sensitivity needs for many applications are not severe, they can be accomplished using an ∼6-mg 252 Cf NAA facility. The SRTC 252 Cf facility continues to support applied research programs at SRTC as well as other SRS programs for environmental and waste management customers. Samples analyzed by NAA include organic compounds, metal alloys, sediments, site process solutions, and many other materials. Numerous radiochemical analyses also rely on the facility for production of short-lived tracers, yielding by activation of carriers and small-scale isotope production for separation methods testing. These applications are more fully reviewed in Ref. 1. Although the flux [approximately2 x 10 7 n/cm 2 ·s] is low relative to reactor facilities, more than 40 elements can be detected at low and sub-part-per-million levels. Detection limits provided by the facility are adequate for many analytical projects. Other multielement analysis methods, particularly inductively coupled plasma atomic emission and inductively coupled plasma mass spectrometry, can now provide sensitivities on dissolved samples that are often better than those available by NAA using low-flux isotopic sources. Because NAA allows analysis of bulk samples, (a) it is a more cost-effective choice when its sensitivity is adequate than methods that require digestion and (b) it eliminates uncertainties that can be introduced by digestion processes

  7. Radionuclide 252Cf neutron source

    International Nuclear Information System (INIS)

    Kolevatov, Yu.I.; Trykov, L.A.

    1979-01-01

    Characteristics of radionuclide neutron sourses of 252 Cf base with the activity from 10 6 to 10 9 n/s have been investigated. Energetic distributions of neutrons and gamma-radiation have been presented. The results obtained have been compared with other data available. The hardness parameter of the neutron spectrum for the energy range from 3 to 15 MeV is 1.4 +- 0.02 MeV

  8. Monte Carlo simulation using MCNP4B for an optimal shielding design of a 252 Cf source

    International Nuclear Information System (INIS)

    Silva, Ademir X. da; Crispim, Verginia R.

    2001-01-01

    This study aim to investigate an optimum shielding design against neutrons and gamma-rays from a source of 252 Cf, using Monte Carlo simulation. The shielding materials studied were: borated polyethylene, borated-lead polyethylene and stainless steel. The Monte Carlo code MCNP, version 4B, was used to design shielding for 252 Cf based neutron irradiator systems. By normalizing the dose equivalent rate values presented to the neutron production rate of the source, the resulting calculations are independents of the intensity of actual 252 Cf source. The results shown what the total dose equivalent rates were reduced significantly by the shielding system optimization. (author)

  9. Analysis of geological material and especially ores by means of a 252Cf source

    International Nuclear Information System (INIS)

    Barrandon, J.N.; Borderie, B.; Melky, S.; Halfon, J.; Marce, A.

    1976-01-01

    Tests were made on the possibilities for analysis by 252 Cf activation in the earth sciences and mining research. The results obtained show that while 252 Cf activation can only resolve certain very specific geochemical research problems, it does allow the exact and rapid determination of numerous elements whose ores are of great economic importance such as fluorine, titanium, vanadium, manganese, copper, antimony, barium, and tungsten. The utilization of activation analysis methods in the earth sciences is not a recent phenomenon. It has generally been limited to the analysis of traces in relatively small volumes by means of irradiation in nuclear reactors. Traditional neutron sources were little used and were not very applicable. The development of 252 Cf isotopic sources emitting more intense neutron fluxes make it possible to consider carrying out more sensitive determinations without making use of a nuclear reactor. In addition, this technique can be adapted for in situ analysis in mines and mine borings. Our work which is centered upon the possibilities of instrumental laboratory analyses of geological materials through 252 Cf activation is oriented in two principal directions: the study of the experimental sensitivities of the various elements in different rocks with the usual compositions; and the study of the possibilities for routine ore analyses

  10. Calculation of dose distribution for 252Cf fission neutron source in tissue equivalent phantoms using Monte Carlo method

    International Nuclear Information System (INIS)

    Ji Gang; Guo Yong; Luo Yisheng; Zhang Wenzhong

    2001-01-01

    Objective: To provide useful parameters for neutron radiotherapy, the author presents results of a Monte Carlo simulation study investigating the dosimetric characteristics of linear 252 Cf fission neutron sources. Methods: A 252 Cf fission source and tissue equivalent phantom were modeled. The dose of neutron and gamma radiations were calculated using Monte Carlo Code. Results: The dose of neutron and gamma at several positions for 252 Cf in the phantom made of equivalent materials to water, blood, muscle, skin, bone and lung were calculated. Conclusion: The results by Monte Carlo methods were compared with the data by measurement and references. According to the calculation, the method using water phantom to simulate local tissues such as muscle, blood and skin is reasonable for the calculation and measurements of dose distribution for 252 Cf

  11. Determining {sup 252}Cf source strength by absolute passive neutron correlation counting

    Energy Technology Data Exchange (ETDEWEB)

    Croft, S. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6166 (United States); Henzlova, D., E-mail: henzlova@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2013-06-21

    Physically small, lightly encapsulated, radionuclide sources containing {sup 252}Cf are widely used for a vast variety of industrial, medical, educational and research applications requiring a convenient source of neutrons. For many quantitative applications, such as detector efficiency calibrations, the absolute strength of the neutron emission is needed. In this work we show how, by using a neutron multiplicity counter the neutron emission rate can be obtained with high accuracy. This provides an independent and alternative way to create reference sources in-house for laboratories such as ours engaged in international safeguards metrology. The method makes use of the unique and well known properties of the {sup 252}Cf spontaneous fission system and applies advanced neutron correlation counting methods. We lay out the foundation of the method and demonstrate it experimentally. We show that accuracy comparable to the best methods currently used by national bodies to certify neutron source strengths is possible.

  12. Exclusive radiation therapy of endometrial carcinoma using HDR Co-60 and Cf-252 sources

    International Nuclear Information System (INIS)

    Inciura, A.; Janulionis, E.; Atkocius, V.

    2000-01-01

    Although the main treatment of endometrial cancer is surgery, the gross spread of carcinoma in pelvis, elderly age of the patients and serious therapeutical diseases do not allow to operate 20% of the patients. For these patients only radical treatment decision is the combined radiation therapy. However, using various modalities of combined radiotherapy, the treatment results are not satisfying: only 52% of patients survive 5 years. There was implemented a new method of combined radiotherapy, using a three-channel applicator with two-positional locating of HDR Co-60 radioactive sources (group I). A new method of brachytherapy for endometrial carcinoma using a HDR Cf 252 sources (group II) was implemented too. For group I the medium total dose of the point A was 77.6 Gy, point I - 69.6 Gy. point 2 - 84.2 Gy, point B - 52.6 Gy, For group II the medium total dose the points A, 3 and 4 was 50 iGy. For group I 1 year overaII survival rate was 85%, 3 year - 73%. The 3 year survival rate for stage I was 79%, for stage II - 89%, for stage III - 33%. 3 year survival for highly virulent tumours - 56% and for low virulent (adenocarcinoma) - 82% was statistically different. The loss of tumour differentiation correlated with the worse prognosis: 3 year survival for G1 and G2 tumours was 92%, for G3 - 45%. Low hemoglobin level was also associated with low survival rate: 2 year survival for Hb≥120g/l was 85% and Hb<120g/l - 23%. 1 year survival rate was 87%, 3 year - 66%, 5 year - 58% for group II, treated with Cf-252. Radiation complications occurred for 13.8% of the patients for group I and 6.2% for group II. Good survival rates and a small number of complications sufficiently proofed treatment method. (author)

  13. Frequency spectrum analysis of 252Cf neutron source based on LabVIEW

    International Nuclear Information System (INIS)

    Mi Deling; Li Pengcheng

    2011-01-01

    The frequency spectrum analysis of 252 Cf Neutron source is an extremely important method in nuclear stochastic signal processing. Focused on the special '0' and '1' structure of neutron pulse series, this paper proposes a fast-correlation algorithm to improve the computational rate of the spectrum analysis system. And the multi-core processor technology is employed as well as multi-threaded programming techniques of LabVIEW to construct frequency spectrum analysis system of 252 Cf neutron source based on LabVIEW. It not only obtains the auto-correlation and cross correlation results, but also auto-power spectrum,cross-power spectrum and ratio of spectral density. The results show that: analysis tools based on LabVIEW improve the fast auto-correlation and cross correlation code operating efficiency about by 25% to 35%, also verify the feasibility of using LabVIEW for spectrum analysis. (authors)

  14. A new facility for non-destructive assay using a 252Cf source

    International Nuclear Information System (INIS)

    Stevanato, L.; Caldogno, M.; Dima, R.; Fabris, D.; Hao, Xin; Lunardon, M.; Moretto, S.; Nebbia, G.; Pesente, S.; Pino, F.; Sajo-Bohus, L.; Viesti, G.

    2013-01-01

    A new laboratory facility for non-destructive analysis (NDA) using a time-tagged 252 Cf source is presented. The system is designed to analyze samples having maximum size of about 20×25 cm 2 , the material recognition being obtained by measuring simultaneously total and energy dependent transmission of neutrons and gamma rays. The equipment technical characteristics and performances of the NDA system are presented, exploring also limits due to the sample thickness. Some recent applications in the field of cultural heritage are presented. - Highlights: ► Tagged 252 Cf source setup. ► Material recognition and sample imaging with measurements of gamma ray and neutron transmission. ► Material identification via energy dependent neutron and gamma ray transmission measurements. ► Identification of layered material. ► Effects due to the sample thickness on the above identification techniques

  15. INAA using 252Cf neutron source at University of Pune

    International Nuclear Information System (INIS)

    Rajurkar, N.S.

    2006-01-01

    The review presents the work done over last two decades on Instrumental Neutron Activation Analysis (INAA) by our research group at University of Pune using 252 Cf spontaneous fission neutron source. The technique has been applied in different fields viz. numismatics, industry, agriculture, ayurveda, environmental and health sciences and diffusion studies. A brief discussion of the work is presented in this article. (author)

  16. Design of a setup for {sup 252}Cf neutron source for storage and analysis purpose

    Energy Technology Data Exchange (ETDEWEB)

    Hei, Daqian [Department of Nuclear Science and Engineering, College of Materials Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106 (China); Zhuang, Haocheng [Xi’an Middle School of Shanxi Province, Xi’an 710000 (China); Jia, Wenbao, E-mail: jiawenbao@163.com [Department of Nuclear Science and Engineering, College of Materials Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106 (China); Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou 215000 (China); Cheng, Can; Jiang, Zhou; Wang, Hongtao [Department of Nuclear Science and Engineering, College of Materials Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106 (China); Chen, Da [Department of Nuclear Science and Engineering, College of Materials Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106 (China); Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou 215000 (China)

    2016-11-01

    {sup 252}Cf is a reliable isotopic neutron source and widely used in the prompt gamma ray neutron activation analysis (PGNAA) technique. A cylindrical barrel made by polymethyl methacrylate contained with the boric acid solution was designed for storage and application of a 5 μg {sup 252}Cf neutron source. The size of the setup was optimized with Monte Carlo code. The experiments were performed and the results showed the doses were reduced with the setup and less than the allowable limit. The intensity and collimating radius of the neutron beam could also be adjusted through different collimator.

  17. Laboratory-scale shielded cell for 252Cf

    International Nuclear Information System (INIS)

    Anderl, R.A.; Cargo, C.H.

    1979-01-01

    A shielded-cell facility for storing and handling remotely up to 2 milligram quantities of unencapsulated 252 Cf has been built in a radiochemistry laboratory at the Test Reactor Area of the Idaho National Engineering Laboratory. Unique features of this facility are its compact bulk radiation shield of borated gypsum and transfer lines which permit the transport of fission product activity from 252 Cf fission sources within the cell to a mass separator and to a fast radiochemistry system in nearby rooms

  18. A pneumatic transfer system for special form 252Cf

    International Nuclear Information System (INIS)

    Gehrke, R.J.; Berry, S.M.; Grafwallner, E.G.; Hoggan, J.M.

    1996-09-01

    A pneumatic transfer system has been developed for use with series 100 Special Form 252 Cf. It was developed to reduce the exposure to personnel handling sources of 252 Cf with masses up to 150 microg by permitting remotely activated two-way transfer between the storage container and the irradiation position. The pneumatic transfer system also permits transfers for reproducible repetitive irradiation periods. In addition to the storage container equipped with quick-release fittings, the transfer system consists of an irradiation station, a control box with momentary contact switches to activate the air-pressure control valves and indicators to identify the location of the source, and connecting air hose and electrical wire. A source of 20 psig air and 110 volt electrical power are required for operation of the transfer system which can be easily moved and set up by one individual in 5 to 10 minutes. Tests have shown that rarely does a source become lodged in the transfer tubing, but two methods have been developed to handle incomplete transfers of the 252 Cf source. The first method consists of closing one air vent to allow a pressure impulse to propel the source to the opposite side. The second method applies to those 252 Cf capsules with a threaded or tapped end to which a small ferromagnetic piece can be attached; an incompletely transferred source in the transfer tube can then be guided to a position of safety by surrounding the transfer tubing containing the capsule with a horseshoe magnet attached to the end of a long pole

  19. Validating criticality calculations for spent fuel with 252Cf-source-driven noise measurements

    International Nuclear Information System (INIS)

    Mihalczo, J.T.; Krass, A.W.; Valentine, T.E.

    1992-01-01

    The 252 Cf-Source-driven noise analysis method can be used for measuring the subcritical neutron multiplication factor k of arrays of spent light water reactor (LWR) fuel. This type of measurement provides a parameter that is directly related to the criticality state of arrays of LWR fuel. Measurements of this parameter can verify the criticality safety margins of spent LWR fuel configurations and thus could be a means of obtaining the information to justify burnup credit for spent LWR transportation/storage casks. The practicality of a measurement depends on the ability to install the hardware required to perform the measurement. Source chambers containing the 252 Cf at the required source intensity for this application have been constructed and have operated successfully for ∼10 years and can be fabricated to fit into control rod guide tubes of PWR fuel elements. Fission counters especially developed for spent-fuel measurements are available that would allow measurements of a special 3 x 3 spent fuel array and a typical burnup credit rail cask with spent fuel in unborated water. Adding a moderator around these fission counters would allow measurements with the typical burnup credit rail cask with borated water and the special 3 x 3 array with borated water. The recent work of Ficaro on modifying the KENO Va code to calculate by the Monte Carlo method the time sequences of pulses at two detectors near a fissile assembly from the fission chain multiplication process, initiated by a 252 Cf source in the assembly allows a direct computer calculation of the noise analysis data from this measurement method

  20. Neutron dose rate for {sup 252} Cf AT source in medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Paredes, L.; Balcazar, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico); Francois, J.L. [FI-UNAM, 04510 Mexico D.F. (Mexico)

    2006-07-01

    The AAPM TG-43 modified protocol was used for the calculation of the neutron dose rate of {sup 252}Cf sources for two tissue substitute materials, five normal tissues and six tumours. The {sup 252}Cf AT source model was simulated using the Monte Carlo MCNPX code in spherical geometry for the following factors: a) neutron air kerma strength conversion factor, b) dose rate constant, c) radial dose function, d) geometry factor, e) anisotropy function and f) neutron dose rate. The calculated dose rate in water at 1 cm and 90 degrees from the source long axis, using the Watt fission spectrum, was D{sub n}(r{sub 0}, {theta}{sub 0})= 1.9160 cGy/h-{mu}g. When this value is compared with Rivard et al. calculation using MCNP4B code, 1.8730 cGy/h-{mu}g, a difference of 2.30% is obtained. The results for the reference neutron dose rate in other media show how small variations in the elemental composition between the tissues and malignant tumours, produce variations in the neutron dose rate up to 12.25%. (Author)

  1. Efficacy of brachytherapy with californium-252 neutrons versus cesium-137 photons for eradication of bulky localized cervical cancer: single-institution study

    International Nuclear Information System (INIS)

    Maruyama, Y.; van Nagell, J.R.; Yoneda, J.; Donaldson, E.; Gallion, H.; Higgins, R.; Powell, D.; Turner, C.; Kryscio, R.

    1988-01-01

    A fast-neutron-emitting radioisotope, 252 Cf, is being tested in clinical trials of neutron brachytherapy for cervical cancer. The efficacy for histological eradication of bulky stage IB cervical tumors (mean diameter, approximately 6 cm) using combined radiation and surgery was studied in 65 patients treated with 137 Cs or 252 Cf before surgery during 1983-1986. Forty-four patients were treated with 137 Cs and 21 were treated with 252 Cf at equivalent doses of radiation. Fifteen of the 44 specimens (34%) were positive after 137Cs therapy. Only one of the 21 specimens was positive after 252 Cf therapy (P = .025), and that patient was treated in a delayed schedule 21 days after the start of external-beam irradiation rather than early in the course. 252 Cf therapy required a much lower radiation dose and shorter treatment time. The study compared tumor destruction of an identically staged human cervical tumor in situ by direct histological means, using 252 Cf neutron therapy or conventional photon therapy at an identical and equivalent dose adjusted by a relative biological effectiveness of 6.0 for 252 Cf

  2. Testing Moderating Detection Systems with 252Cf-Based Reference Neutron Fields

    International Nuclear Information System (INIS)

    Hertel, Nolan E.; Sweezy, Jeremy; Sauber, Jeremiah S.; Vaughn, David; Cook, Andrew; Tays, Jeff; Ro, Tae-Ik

    2001-01-01

    Calibration measurements were carried out on a probe designed to measure ambient dose equivalent in accordance with ICRP Pub 60 recommendations. It consists of a cylindrical 3 He proportional counter surrounded by a 25-cm-diameter spherical polyethylene moderator. Its neutron response is optimized for dose rate measurements of neutrons between thermal energies and 20 MeV. The instrument was used to measure the dose rate in four separate neutron fields: unmoderated 252 Cf, D 2 O-moderated 252 Cf, polyethylene-moderated 252 Cf, and WEP neutron howitzer with 252 Cf at its center. Dose equivalent measurements were performed at source-detector centerline distances from 50 to 200 cm. The ratio of air-scatter- and room-return-corrected ambient dose equivalent rates to ambient dose equivalent rates calculated with the code MCNP are tabulated

  3. Fresnel zone plate imaging of a 252Cf spontaneous fission source

    International Nuclear Information System (INIS)

    Stalker, K.T.; Hessel, K.R.

    1976-11-01

    The feasibility of coded aperture imaging for nuclear fuel motion monitoring is shown using Cf 252 spontaneous fission source. The theory of coded aperture imaging for Fresnel zone plate apertures is presented and design considerations for zone plate construction are discussed. Actual images are obtained which demonstrate a transverse resolution of 1.7 mm and a tomographic resolution of 1.5 millimeters. The capability of obtaining images through 12.7 mm of stainless steel is also shown

  4. Fabrication of 50-mg 252Cf neutron sources for the FDA [Food and Drug Administration] activation analysis facility

    International Nuclear Information System (INIS)

    Bigelow, J.E.; Cagle, E.B.; Knauer, J.B.

    1987-01-01

    The Transuranium Processing Plant (TPP) at ORNL has been requested by the Food and Drug Administration (FDA) to furnish 200 mg of 252 Cf for use in their new activation analysis facility. This paper discusses the procedure to be employed in fabricating the californium into four neutron sources, each containing a nominal 50-mg of 252 Cf. The ORNL Model LSD (Large, Stainless steel, Doubly encapsulated) neutron source consists of a 6.33-mm-diam aluminum pellet doubly encapsulated in Type 304L stainless steel. The pellet is comprised of an aluminum tube holding Cf 2 O 2 SO 4 microspheres confined by pressed aluminum powder. The microspheres are prepared in a separate vessel and then transferred into the specially designed aluminum tube prior to pressing

  5. A survey of uses and users of 252Cf

    International Nuclear Information System (INIS)

    Bigelow, J.E.; Alexander, C.W.; King, L.J.; Knauer, J.B.; Notz, K.J.

    1989-01-01

    Californium-252, which is one of the transuranium-element isotopes being produced in the Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL), has found many applications in service to industry and medicine. As a neutron source, 252 Cf is unique in providing a highly concentrated and extremely reliable neutron spectrum from a very small assembly. Over the past 22 years, 252 Cf has been applied with great success to cancer therapy, to neutron radiography of objects ranging from flowers to entire aircraft, to startup sources for nuclear reactors, to fission activation assay for quality control and safeguards of all commercial nuclear fuel, and to many other beneficial uses, some of which are now poised for further growth. The extensive exploitation of this highly specialized product has been made possible through 252 Sales/Loan programs sponsored by the US DOE Office of Nuclear Materials Production, initially at the Savannah River Laboratory and now at ORNL

  6. Regularities in dose field formation for fixation of 252Cf and 60Co sources on the same plane

    International Nuclear Information System (INIS)

    Ivanov, V.N.; Vtyurin, B.M.; Ivanova, L.F.; Kondzhariya, Yu.R.

    1983-01-01

    A computerized study was made of a change in the correlation between the sizes of an irradiated volume and the distribution of sources. Criteria have been established for the utilization of 252 Cf and 60 Co sources of different active length and design placed on the same plane. Reference dose rate and its derivatives have been chosen as the main parameters that characterize a dose field. A dosimetric analysis was performed using the data for an adsorbed dose of neutrons in the tissue, taking account of high RBE of 252 Cf fast neutrons that equals 6-7, and a slight change of the local RBE value near the source resulting from a change of the effective spectrum of neutrons in combination with the growth of a contribution of #betta#-radiation into the summary dose with the removal from the source. The irradiated volume was evaluated by introducing 3 linear parameters - length, thickness and width. It has been shown that the ratio of the length of an irradiated volume to the active length of 252 Cf sources with radionuclide regular linear density changes from 0.7 with the isodose value of 85% up to 0.97 with the isodose value of 60%. For 60 Co sources with a higher linear density of the radionuclide on the edges the lower limit of this value equals 1. Intervals of changes in the rest of parameters have also been defined. The results obtained are presented graphically. The results of the study are used for a dosimetric control of the clinical trials of 252 Cf and 60 Co sources in the treatment of patients with tumors of the tongue, oral cavity fundus, lip and other sites

  7. Californium-252 radiotherapy sources for interstitial afterloading

    International Nuclear Information System (INIS)

    Permar, P.H.; Walker, V.W.

    1976-01-01

    Californium-252 neutron sources for interstitial afterloading were developed to investigate the value of this radionuclide in cancer therapy. Californium-252 seed assemblies contain essentially point sources of 252 Cf permanently sealed on 1-cm centers within a flexible plastic tube. The seed assemblies are fabricated with remotely operated, specially designed machines. The fabrication process involves the production of a Pt-10 percent Ir-clad wire with a 252 Cf 2 O 3 -Pd cermet core. The wire is swaged and drawn to size, cut to length, and welded in a Pt-10 percent Ir capsule 0.8 mm in diameter and 6 mm long. Each seed capsule contains approximately 0.5 microgram of 252 Cf. Because the effective half-life of 252 Cf is 2.6 years, the seed assemblies are not disposable and must be reused until their activities have decreased to unsuitable levels. The flexible plastic components must therefore have sufficient resistance to radiation damage to survive the neutron-plus-gamma radiation from 252 Cf. On the basis of accelerated irradiation tests with a large 252 Cf source, a recently developed fluoropolymer, ''Tefzel'' (trademark of E. I. du Pont de Nemours and Company) has adequate radiation resistance for this application. Californium-252 seed assembly systems are loaned by the United States Energy Research and Development Administration for clinical investigations under a protocol of the Radiation Therapy Oncology Group, U.S. National Cancer Institute

  8. 252Cf-source-driven noise analysis measurements for characterization of concrete highly enriched uranium (HEU) storage vaults

    International Nuclear Information System (INIS)

    Valentine, T.E.; Mihalczo, J.T.

    1993-01-01

    The 252 Cf-source-driven noise analysis method has been used in measurements for subcritical configurations of fissile systems for a variety of applications. Measurements of 25 fissile systems have been performed with a wide variety of materials and configurations. This method has been applied to measurements for (1) initial fuel loading of reactors, (2) quality assurance of reactor fuel elements, (3) fuel preparation facilities, (4) fuel processing facilities, (5) fuel storage facilities, (6) zero-power testing of reactors, and (7) verification of calculational methods for assemblies with the neutron k 252 Cf source and commercially available detectors was feasible and to determine if the measurement could characterize the ability of the concrete to isolate the fissile material

  9. Shielding experiments in different materials with 252Cf neutron spectra

    International Nuclear Information System (INIS)

    Sathian, Deepa; Marathe, P.K.; Pal, Rupali; Jayalakshmi, V.; Chourasiya, G.; Mayya, Y.S.

    2008-01-01

    Adequate shielding for neutron sources can be determined using analytical method or by actually measuring the attenuation for the target configuration. This paper describes the measurement of Half Value Thickness (HVT), Tenth Value Thickness (TVT), Σ values for four different shielding materials, using a standard 252 Cf neutron source and comparing with the values calculated using an empirical relationship. BF 3 based REM-counter is used for measurement of neutron dose equivalent, against different thickness of the shielding material. The experimental HVT and S values are in good agreement with the calculated values. From this study, it is concluded that, among the four materials studied, high density polyethylene (HDPE) is best suitable for the shielding of a 252 Cf neutron source. (author)

  10. 252Cf-source-driven neutron noise analysis method

    International Nuclear Information System (INIS)

    Mihalczo, J.T.; King, W.T.; Blakeman, E.D.

    1985-01-01

    The 252 Cf-source-driven neutron noise analysis method has been tested in a a wide variety of experiments that have indicated the broad range of applicability of the method. The neutron multiplication factor, k/sub eff/ has been satisfactorily determined for a variety of materials including uranium metal, light water reactor fuel pins, fissile solutions, fuel plates in water, and interacting cylinders. For a uranyl nitrate solution tank which is typical of a fuel processing or reprocessing plant, the k/sub eff/ values were satisfactorily determined for values between 0.92 and 0.5 using a simple point kinetics interpretation of the experimental data. The short measurement times, in several cases as low as 1 min, have shown that the development of this method can lead to a practical subcriticality monitor for many in-plant applications. The further development of the method will require experiments and the development of theoretical methods to predict the experimental observables

  11. 252Cf-source-driven neutron noise analysis method

    International Nuclear Information System (INIS)

    Mihalczo, J.T.; King, W.T.; Blakeman, E.D.

    1985-01-01

    The 252 Cf-source-driven neutron noise analysis method has been tested in a wide variety of experiments that have indicated the broad range of applicability of the method. The neutron multiplication factor k/sub eff/ has been satisfactorily detemined for a variety of materials including uranium metal, light water reactor fuel pins, fissile solutions, fuel plates in water, and interacting cylinders. For a uranyl nitrate solution tank which is typical of a fuel processing or reprocessing plant, the k/sub eff/ values were satisfactorily determined for values between 0.92 and 0.5 using a simple point kinetics interpretation of the experimental data. The short measurement times, in several cases as low as 1 min, have shown that the development of this method can lead to a practical subcriticality monitor for many in-plant applications. The further development of the method will require experiments oriented toward particular applications including dynamic experiments and the development of theoretical methods to predict the experimental observables

  12. Californium-252 interstitial implants in carcinoma of the tongue

    International Nuclear Information System (INIS)

    Vtyurin, B.M.; Ivanov, V.N.; Medvedev, V.S.; Galantseva, G.F.; Abdulkadyrov, S.A.; Ivanova, L.F.; Petrovskaya, G.A.; Plichko, V.I.

    1985-01-01

    A clinical study using 252 Cf sources in brachytherapy of tumors began in the Research Institute of Medical Radiology of the Academy of Medical Sciences of the USSR in 1973. 252 Cf afterloading cells were utilized by the method of simple afterloading. Dosimetry and radiation protection of medical personnel were developed. To substantiate optimal therapeutic doses of 252 Cf neutrons, a correlation of dose, time, and treatment volume factors with clinical results of 252 Cf interstitial implants in carcinoma of the tongue for 47 patients with a minimum follow-up period of 1 year was studied. Forty-nine interstitial implants have been performed. Seventeen patients received 252 Cf implants alone (Group I), 17 other patients received 252 Cf implants in combination with external radiation (Group II), and 15 patients were treated with interstitial implants for recurrent or residual tumors (Groups III). Complete regression of carcinoma of the tongue was obtained in 48 patients (98%). Thirteen patients (27%) developed radiation necrosis. The therapeutic dose of neutron radiation from 252 Cf sources in interstitial radiotherapy of primary tongue carcinomas (Group I) was found to be 7 to 9 Gy. Optimal therapeutic neutron dose in combined interstitial and external radiotherapy of primary tumors (Group II) was 5 to 6 Gy with an external radiation dose of 40 Gy. For recurrent and residual tumors (Group III), favorable results were obtained with tumor doses of 6.5 to 7 Gy

  13. Photon contributions from the 252Cf and 241Am–Be neutron sources at the PSI Calibration Laboratory

    International Nuclear Information System (INIS)

    Hoedlmoser, H.; Boschung, M.; Meier, K.; Stadtmann, H.; Hranitzky, C.; Figel, M.; Mayer, S.

    2012-01-01

    At the accredited PSI Calibration Laboratory neutron reference fields traceable to the national standards of the Physikalisch-Technische Bundesanstalt (PTB) in Germany are available for the calibration of ambient and personal dose equivalent (rate) meters and passive dosimeters. The photon contribution to the ambient dose equivalent in the neutron fields of the 252 Cf and 241 Am–Be sources was measured using various photon dose rate meters and active and passive dosimeters. Measuring photons from a neutron source usually involves considerable uncertainties due to the presence of neutron induced photons in the room, due to a non-zero neutron sensitivity of the photon detector, and last but not least due to the energy response of the photon detectors. Therefore eight independent detectors and methods were used to obtain a reliable estimate for the photon contribution of the two sources as an average of the individual methods. For the 241 Am–Be source a photon contribution of approximately 4.9% was determined and for the 252 Cf source a contribution of 3.6%.

  14. A new facility for non-destructive assay using a 252Cf source.

    Science.gov (United States)

    Stevanato, L; Caldogno, M; Dima, R; Fabris, D; Hao, Xin; Lunardon, M; Moretto, S; Nebbia, G; Pesente, S; Pino, F; Sajo-Bohus, L; Viesti, G

    2013-03-01

    A new laboratory facility for non-destructive analysis (NDA) using a time-tagged (252)Cf source is presented. The system is designed to analyze samples having maximum size of about 20 × 25 cm(2), the material recognition being obtained by measuring simultaneously total and energy dependent transmission of neutrons and gamma rays. The equipment technical characteristics and performances of the NDA system are presented, exploring also limits due to the sample thickness. Some recent applications in the field of cultural heritage are presented. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Use of californium-252 sources in Hungary for teaching and research

    International Nuclear Information System (INIS)

    Csikai, J.

    1976-01-01

    An activation facility was designed to accommodate up to 50 mg of 252 Cf; it contains at present a 500 μg source. The absolute values of thermal, epithermal and fast neutron fluxes were determined by the foil activation method using In, Dy, Au, Al and Fe detectors. Cross-sections averaged for unmoderated 252 Cf neutrons were determined for 22 different reactions for elements with atomic weights lying between A=27 and 204. The sensitivity for determination of Al, Ti, Cu, As, Sr, Mo, In, Cd, Ba, Au, Hg and Pb was calculated for NaI(Tl) and Ge(Li) detectors. Average (n,2n) cross-sections for 252 Cf spectrum were calculated for 49 nuclei lying between A=14 and 204. Angular distributions and cross-sections for the fragments from 252 Cf neutron-induced fission of 232 Th and 238 U were measured. Titanium in bauxite and manganese in aluminium alloys were determined with a 252 Cf source. The applicability of solid-state track detectors for neutron dosimetry, radiography and for the determination of fuel burn-up were investigated using 252 Cf neutron and fragment sources. Characteristics of a jumping spark counter for counting fission fragments were studied with 252 Cf sources. (author)

  16. Shielding evaluation of a medical linear accelerator vault in preparation for installing a high-dose rate 252Cf remote after-loader

    International Nuclear Information System (INIS)

    Melhus, C. S.; Rivard, M. J.; KurKomelis, J.; Liddle, C. B.; Masse, F. X.

    2005-01-01

    In support of the effort to begin high-dose rate 252 Cf brachytherapy treatments at Tufts-New England Medical Center, the shielding capabilities of a clinical accelerator vault against the neutron and photon emissions from a 1.124 mg 252 Cf source were examined. Outside the clinical accelerator vault, the fast neutron dose equivalent rate was below the lower limit of detection of a CR-39 etched track detector and below 0.14 ± 0.02 μSv h -1 with a proportional counter, which is consistent, within the uncertainties, with natural background. The photon dose equivalent rate was also measured to be below background levels (0.1 μSv h -1 ) using an ionisation chamber and an optically stimulated luminescence dosemeter. A Monte Carlo simulation of neutron transport through the accelerator vault was performed to validate measured values and determine the thermal-energy to low-energy neutron component. Monte Carlo results showed that the dose equivalent rate from fast neutrons was reduced by a factor of 100,000 after attenuation through the vault wall, and the thermal-energy neutron dose equivalent rate would be an additional factor of 1000 below that of the fast neutrons. Based on these findings, the shielding installed in this facility is sufficient for the use of at least 5.0 mg of 252 Cf. (authors)

  17. Neutron calibration field of bare {sup 252}Cf source in Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Le, Ngoc Thiem; Tran, Hoai Nam; Nguyen, Khai Tuan [Institute for Nuclear Science and Technology, Hanoi (Viet Nam); Trinh, Glap Van [Institute of Research and Development, Duy Tan University, Da Nang (Viet Nam)

    2017-02-15

    This paper presents the establishment and characterization of a neutron calibration field using a bare {sup 252}Cf source of low neutron source strength in Vietnam. The characterization of the field in terms of neutron flux spectra and neutron ambient dose equivalent rates were performed by Monte Carlo simulations using the MCNP5 code. The anisotropy effect of the source was also investigated. The neutron ambient dose equivalent rates at three reference distances of 75, 125, and 150 cm from the source were calculated and compared with the measurements using the Aloka TPS-451C neutron survey meters. The discrepancy between the calculated and measured values is found to be about 10%. To separate the scattered and the direct components from the total neutron flux spectra, an in-house shadow cone of 10% borated polyethylene was used. The shielding efficiency of the shadow cone was estimated using the MCNP5 code. The results confirmed that the shielding efficiency of the shadow cone is acceptable.

  18. Ternary-fragmentation-driving potential energies of 252Cf

    Science.gov (United States)

    Karthikraj, C.; Ren, Zhongzhou

    2017-12-01

    Within the framework of a simple macroscopic model, the ternary-fragmentation-driving potential energies of 252Cf are studied. In this work, all possible ternary-fragment combinations of 252Cf are generated by the use of atomic mass evaluation-2016 (AME2016) data and these combinations are minimized by using a two-dimensional minimization approach. This minimization process can be done in two ways: (i) with respect to proton numbers (Z1, Z2, Z3) and (ii) with respect to neutron numbers (N1, N2, N3) of the ternary fragments. In this paper, the driving potential energies for the ternary breakup of 252Cf are presented for both the spherical and deformed as well as the proton-minimized and neutron-minimized ternary fragments. From the proton-minimized spherical ternary fragments, we have obtained different possible ternary configurations with a minimum driving potential, in particular, the experimental expectation of Sn + Ni + Ca ternary fragmentation. However, the neutron-minimized ternary fragments exhibit a driving potential minimum in the true-ternary-fission (TTF) region as well. Further, the Q -value energy systematics of the neutron-minimized ternary fragments show larger values for the TTF fragments. From this, we have concluded that the TTF region fragments with the least driving potential and high Q values have a strong possibility in the ternary fragmentation of 252Cf. Further, the role of ground-state deformations (β2, β3, β4, and β6) in the ternary breakup of 252Cf is also studied. The deformed ternary fragmentation, which involves Z3=12 -19 fragments, possesses the driving potential minimum due to the larger oblate deformations. We also found that the ground-state deformations, particularly β2, strongly influence the driving potential energies and play a major role in determining the most probable fragment combinations in the ternary breakup of 252Cf.

  19. Determination of kinetics parameters using stochastic methods in a 252Cf system

    International Nuclear Information System (INIS)

    Difilippo, F.C.

    1988-01-01

    Safety analysis and control system design of nuclear systems require the knowledge of neutron kinetics related parameters like effective delayed neutron fraction, neutron lifetime, time between neutron generations and subcriticality margins. Many methods, deterministic and stochastic, are being used, some since the beginning of nuclear power, to measure these important parameters. The method based on the use of the 252 Cf neutron source has been under intense study at the Oak Ridge National Laboratory, both experimentally and theoretically, during the last years. The increasing demand for this isotope in industrial and medical applications and new designs of advanced high flux reactors to produce it make the isotope available as neutron source (only few micrograms are necessary). A thin layer of 252 Cf is deposited in one of the electrodes of a fission chamber which produces pulses each time the 252 Cf disintegrates via α or spontaneous fission decay; the smaller pulses associated with the α decay can be easily discriminated with the important result that we known the time when v/sub c/ neutrons are injected into the system (number of neutrons per fission of 252 Cf). Thus, a small (few cm 3 ) and nonintrusive device can be used as a random pulsed neutron source with known natural properties that do no depend on biases associated with more complex interrogating devices like accelerators. This paper presents a general formalism that relates the kinetics parameters with stochastic descriptors that naturally appear because of the random nature of the production and transport of neutrons

  20. NAA using Cf-252 after preconcentration

    International Nuclear Information System (INIS)

    Panyo, O.; Moebius, S.; Keller, C.

    1988-01-01

    Neutron activation analysis (NAA) with thermal neutron using Cf-252 sources was applied to elemental analysis of elements in water samples. A high-resolution Ge(Li) detector was employed for gamma-radiation detection. Both suspended particulate matter and liquid fraction were investigated after filtration. Preconcentration method by co-precipitation using iron (III) hydroxide and oxine were chosen for use. Elements which were considered to be able to detect in the present study are Al, As, Cl, K, Mg, Mn, Na, Sr, Ti, U, V and Zn

  1. Development of the neutron reference calibration field using a 252Cf standard source surrounded with PMMA moderators

    International Nuclear Information System (INIS)

    Yoshida, T.; Kanai, K.; Tsujimura, N.

    2002-01-01

    The authors developed the neutron reference calibration fields using a 252 Cf standard source surrounded with PMMA moderators at the Japan Nuclear Cycle Development (JNC), Tokai Works. The moderators are co-axial, hollow cylinders made of lead-contained PMMA with a thickness of 13.5, 35.0, 59.5 and 77.0mm, and the 252 Cf source is guided to the geometric center of moderators by the pneumatic system. These fields can provide the moderated neutron spectra very similar to those encountered around the globe-boxes of the fabrication process of MOX (PuO 2 -UO 2 mixed oxide) fuel. The neutron energy spectrum at the reference calibration point was evaluated from the calculations by MCNP4B and the measurements by the INS-type Bonner multi-sphere spectrometer and the hydrogen-filled proportional counters. The calculated neutron spectra were in good agreements with the measured ones. These fields were characterized in terms of the neutron fluence rate, spectral composition and ambient dose equivalent rate, and have served for the response-characterization of various neutron survey instruments

  2. Physics of the 252Cf-source-driven noise analysis measurement

    International Nuclear Information System (INIS)

    Valentine, T.E.; Mihalczo, J.T.; Perez, R.B.; Mattingly, J.K.

    1997-01-01

    The 252 Cf-source-driven noise analysis method is a versatile measurements tool that has been applied to measurements for initial loading of reactors, quality assurance of reactor fuel elements, fuel processing facilities, fuel reprocessing facilities, fuel storage facilities, zero-power testing of reactors, verification of calculational methods, process monitoring, characterization of storage vaults, and nuclear weapons identification. This method's broad range of application is due to the wide variety of time- and frequency domain signatures, each with unique properties, obtained from the measurement. The following parameters are obtained from this measurement: average detector count rates, detector multiplicities, detector autocorrelations, cross-correlation between detectors, detector autopower spectral densities, cross-power spectral densities between detectors, coherences, and ratios of spectral densities. All of these measured parameters can also be calculated using the MCNP-DSP Monte Carlo code. This paper presents a review of the time-domain signatures obtained from this measurement

  3. Application of californium-252 neutron sources for analytical chemistry

    International Nuclear Information System (INIS)

    Ishii, Daido

    1976-01-01

    The researches made for the application of Cf-252 neutron sources to analytical chemistry during the period from 1970 to 1974 including partly 1975 are reviewed. The first part is the introduction to the above. The second part deals with general review of symposia, publications and the like. Attention is directed to ERDA publishing the periodical ''Californium-252 Progress'' and to a study group of Cf-252 utilization held by Japanese Radioisotope Association in 1974. The third part deals with its application for radio activation analysis. The automated absolute activation analysis (AAAA) of Savannha River is briefly explained. The joint experiment of Savannha River operation office with New Brunswick laboratory is mentioned. Cf-252 radiation source was used for the non-destructive analysis of elements in river water. East neutrons of Cf-252 were used for the quantitative analysis of lead in paints. Many applications for industrial control processes have been reported. Attention is drawn to the application of Cf-252 neutron sources for the field search of neutral resources. For example, a logging sonde for searching uranium resources was developed. the fourth part deals with the application of the analysis with gamma ray by capturing neutrons. For example, a bore hole sonde and the process control analysis of sulfur in fuel utilized capture gamma ray. The prompt gamma ray by capturing neutrons may be used for the nondestructive analysis of enrivonment. (Iwakiri, K.)

  4. Design of a thermal neutron field by 252Cf source for measurement of 10B concentrations in the blood samples for BNCT

    International Nuclear Information System (INIS)

    Naito, H.; Sakurai, Y.; Maruhashi, A.

    2006-01-01

    10 B concentrations in the blood samples for BNCT has been estimated due to amounts of prompt gamma rays from 10 B in the fields of thermal neutrons from a special guide tube attached to research reactor. A system using radioisotopes as the source of thermal neutron fields has advantages that are convenient and low cost because it doesn't need running of a reactor or an accelerator. The validity of 252 Cf as a neutron source for 10 B concentrations detection system was investigated. This system is composed of D 2 O moderator, Pb reflector/filter, C reflector, and LiF filter. A thermal neutron field with low background gamma-rays is obtained. A large source of 252 Cf is required to obtain a sufficient flux. (author)

  5. Production, Distribution, and Applications of Californium-252 Neutron Sources

    International Nuclear Information System (INIS)

    Balo, P.A.; Knauer, J.B.; Martin, R.C.

    1999-01-01

    The radioisotope 252 Cf is routinely encapsulated into compact, portable, intense neutron sources with a 2.6-year half-life. A source the size of a person's little finger can emit up to 10 11 neutrons/s. Californium-252 is used commercially as a reliable, cost-effective neutron source for prompt gamma neutron activation analysis (PGNAA) of coal, cement, and minerals, as well as for detection and identification of explosives, laud mines, and unexploded military ordnance. Other uses are neutron radiography, nuclear waste assays, reactor start-up sources, calibration standards, and cancer therapy. The inherent safety of source encapsulations is demonstrated by 30 years of experience and by U.S. Bureau of Mines tests of source survivability during explosions. The production and distribution center for the U. S Department of Energy (DOE) Californium Program is the Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL). DOE sells 252 Cf to commercial reencapsulators domestically and internationally. Sealed 252 Cf sources are also available for loan to agencies and subcontractors of the U.S. government and to universities for educational, research, and medical applications. The REDC has established the Californium User Facility (CUF) for Neutron Science to make its large inventory of 252 Cf sources available to researchers for irradiations inside uncontaminated hot cells. Experiments at the CUF include a land mine detection system, neutron damage testing of solid-state detectors, irradiation of human cancer cells for boron neutron capture therapy experiments, and irradiation of rice to induce genetic mutations

  6. Bias in calculated keff from subcritical measurements by the 252Cf-source-driven noise analysis method

    International Nuclear Information System (INIS)

    Mihalczo, J.T.; Valentine, T.E.

    1995-01-01

    The development of MCNP-DSP, which allows direct calculation of the measured time and frequency analysis parameters from subcritical measurements using the 252 Cf-source-driven noise analysis method, permits the validation of calculational methods for criticality safety with in-plant subcritical measurements. In addition, a method of obtaining the bias in the calculations, which is essential to the criticality safety specialist, is illustrated using the results of measurements with 17.771-cm-diam, enriched (93.15), unreflected, and unmoderated uranium metal cylinders. For these uranium metal cylinders the bias obtained using MCNP-DSP and ENDF/B-V cross-section data increased with subcriticality. For a critical experiment [height (h) = 12.629 cm], it was -0.0061 ± 0.0003. For a 10.16-cm-high cylinder (k ∼ 0.93), it was 0.0060 ± 0.0016, and for a subcritical cylinder (h = 8.13 cm, k ∼ 0.85), the bias was -0.0137 ± 0.0037, more than a factor of 2 larger in magnitude. This method allows the nuclear criticality safety specialist to establish the bias in calculational methods for criticality safety from in-plant subcritical measurements by the 252 Cf-source-driven noise analysis method

  7. Development of the neutron reference calibration field using a {sup 252}Cf standard source surrounded with PMMA moderators

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, T.; Kanai, K.; Tsujimura, N. [Japan Nuclear Cycle Development Institute, Ibaraki-ken (Japan)

    2002-07-01

    The authors developed the neutron reference calibration fields using a {sup 252} Cf standard source surrounded with PMMA moderators at the Japan Nuclear Cycle Development (JNC), Tokai Works. The moderators are co-axial, hollow cylinders made of lead-contained PMMA with a thickness of 13.5, 35.0, 59.5 and 77.0mm, and the {sup 252} Cf source is guided to the geometric center of moderators by the pneumatic system. These fields can provide the moderated neutron spectra very similar to those encountered around the globe-boxes of the fabrication process of MOX (PuO{sub 2}-UO{sub 2} mixed oxide) fuel. The neutron energy spectrum at the reference calibration point was evaluated from the calculations by MCNP4B and the measurements by the INS-type Bonner multi-sphere spectrometer and the hydrogen-filled proportional counters. The calculated neutron spectra were in good agreements with the measured ones. These fields were characterized in terms of the neutron fluence rate, spectral composition and ambient dose equivalent rate, and have served for the response-characterization of various neutron survey instruments.

  8. Time domain measurements for fast metal assemblies with /sup 252/Cf

    Energy Technology Data Exchange (ETDEWEB)

    Mihalczo, J T

    1975-06-01

    Time correlation measurements between the pulses from an ionization counter containing a /sup 252/Cf neutron source, which provided the initiators of fission chains in a neutron multiplying assembly and from sensors that detected particles from the fission chains are reviewed for fast uranium or plutonium metal assemblies. Comparisons are made between the correlated count rate from a /sup 252/Cf measurement and that from both one and two-detector Rossi-..cap alpha.. measurements. The assemblies studied were (1) unmoderated and polyethylene-moderated uranium (93 wt percent /sup 235/U) cylinders with masses from 12 to 160 kg; prompt neutron decay constants from 3 to 10/sup 3/ to 10/sup 8/ sec/sup -1/ and (2) unmoderated plutonium spheres and parts of spheres with plutonium masses from 2.2 to 16 kg with /sup 240/Pu contents of 4.5 to 20.1 at. percent. Measurements with a delayed critical uranium metal sphere determined the effective delayed neutron fraction and served as the basis for verification of the theory of the /sup 252/Cf measurement method in the time domain within a few per cent. (auth)

  9. Californium-252 Brachytherapy Combined With External-Beam Radiotherapy for Cervical Cancer: Long-Term Treatment Results

    International Nuclear Information System (INIS)

    Lei Xin; Qian Chengyuan; Qing Yi; Zhao Kewei; Yang Zhengzhou; Dai Nan; Zhong Zhaoyang; Tang Cheng; Li Zheng; Gu Xianqing; Zhou Qian; Feng Yan; Xiong Yanli; Shan Jinlu; Wang Dong

    2011-01-01

    Purpose: To observe, by retrospective analysis, the curative effects and complications due to californium-252 ( 252 Cf) neutron intracavitary brachytherapy (ICBT) combined with external-beam radiotherapy (EBRT) in the treatment of cervical cancer. Methods and Materials: From February 1999 to December 2007, 696 patients with cervical cancer (Stages IB to IIIB) were treated with 252 Cf-ICBT in combination of EBRT. Of all, 31 patients were at Stage IB, 104 at IIA, 363 at IIB, 64 at IIIA, and 134 at IIIB. Californium-252 ICBT was delivered at 7–12 Gy per insertion per week, with a total dose of 29–45 Gy to reference point A in three to five insertions. The whole pelvic cavity was treated with 8-MV X-ray external irradiation at 2 Gy per fraction, four times per week. After 16–38 Gy of external irradiation, the center of the whole pelvic field was blocked with a 4-cm-wide lead shield, with a total external irradiation dose of 44–56 Gy. The total treatment course was 5 to 6 weeks. Results: Overall survival rate at 3 and 5 years for all patients was 76.0% and 64.9%, respectively. Disease-free 3- and 5-year survival rates of patients were 71.2% and 58.4%, respectively. Late complications included vaginal contracture and adhesion, radiation proctitis, radiation cystitis, and inflammatory bowel, which accounted for 5.8%, 7.1%, 6.2%, and 4.9%, respectively. Univariate analysis results showed significant correlation of stage, age, histopathologic grade, and lymph node status with overall survival. Cox multiple regression analysis showed that the independent variables were stage, histopathologic grade, tumor size, and lymphatic metastasis in all patients. Conclusion: Results of this series suggest that the combined use of 252 Cf-ICBT with EBRT is an effective method for treatment of cervical cancer.

  10. Sensitivity of various thermoluminescent, radiophotoluminescent and photographic detectors to neutrons emitted by a 252Cf source

    International Nuclear Information System (INIS)

    Spurny, Frantisek; Medioni, Roger; Chapuis, A.; Portal, Guy.

    1975-07-01

    The specific sensitivity of various thermoluminescent, radiophotoluminescent and photographic detectors to the neutron spectrum of a 252 Cf source was measured and the effect of the size and composition of the containers in which they might be put was investigated. PB33 radiophotoluminescent glasses, radiothermoluminescent alumina and calcium sulfate were less sensitive to fission neutrons whereas photographic emulsions were more sensitive. The former should be used for γ detection in mixed fields of photons and fission neutrons [fr

  11. Physical and biological dosimetries of Cf-252 radiation

    International Nuclear Information System (INIS)

    Yamashita, Hisao; Wada, Tadashi; Dokiya, Takushi; Hashimoto, Shozo

    1986-01-01

    Recently Cf-252 sources containing 300 μg have become available in a size identical to 1 Ci of Cs-137 and with the use of remotely controlled afterloading apparatus, safe therapy with little exposure to the therapist is now possible. Radiation leakage from the Cf-252 apparatus and from the treatment room was measured with REM-meter and it was possible to reduce the leakage from the treatment room to less than 1 mrem/h (gamma rays) and 0.5 mrem/h (neutrons). Measurement of fast neutrons was made with a twin chamber composed of a tissue equivalent ionization chamber and a carbon ionization chamber. The neutron dose in air and the absorbed dose in tissue equivalent water tank were measured, which showed that in air, neutrons were 70% and photons were 30% of dose. In water, greater distances from the source, neutrons attenuate and gamma rays increase in dose. The results of studies on the skin reaction of mice and sperm cleavage delay time of sea urchins indicated that the RBE ranges from 1.5 to 3.0 using the high dose rate system. Neutrons are remarkably affected by a time factor. With the use of high dose rate sources, the dose rate has become higher, but the overall time has been extended through dose fractionation and it was considered advisable to employ an RBE of 3-4 in these studies. (Auth.)

  12. Radiation ulcers in patients with cancer of the torgue after 252Cf therapy

    International Nuclear Information System (INIS)

    Galantseva, G.F.; Guseva, L.I.; Plichko, V.I.

    1984-01-01

    Interstitial therapy with 252 Cf was conducted for 57 patients with cancer of the tongue. It was established that clinical course of radiation tungue ulcers after interstitial therapy with 252 Cf doesn't differ sufficiently from the course of radiation injuries, occurring after γ-radiation application. Radiation ulcers are often observed in patients after the treatment of recurrent and residual tumors with 252 Cf (in 33% of patients); the ulcers appeared in 15% of cases in patients after the treatment of initial ulcers tumors. Conservative treatment provide the cure of radiation tongUe ulcers after interstitial therapy with 252 Cf

  13. Cf-252 based neutron radiography using real-time image processing system

    International Nuclear Information System (INIS)

    Mochiki, Koh-ichi; Koiso, Manabu; Yamaji, Akihiro; Iwata, Hideki; Kihara, Yoshitaka; Sano, Shigeru; Murata, Yutaka

    2001-01-01

    For compact Cf-252 based neutron radiography, a real-time image processing system by particle counting technique has been developed. The electronic imaging system consists of a supersensitive imaging camera, a real-time corrector, a real-time binary converter, a real-time calculator for centroid, a display monitor and a computer. Three types of accumulated NR image; ordinary, binary and centroid images, can be observed during a measurement. Accumulated NR images were taken by the centroid mode, the binary mode and ordinary mode using of Cf-252 neutron source and those images were compared. The centroid mode presented the sharpest image and its statistical characteristics followed the Poisson distribution, while the ordinary mode showed the smoothest image as the averaging effect by particle bright spots with distributed brightness was most dominant. (author)

  14. Study the Possibility of measuring Heavy Metals Arising from Gold Mining Sample using 252Cf Neutron Source

    International Nuclear Information System (INIS)

    Soliman, N.F.

    2012-01-01

    Mining activities contribute immensely to trace element pollution .The present work studied the possibility of measuring heavy metals arising from gold mining areas Eastern Desert in Egypt using the isotopic 252 Cf neutron source. 38.5 g of the sample is irradiated in a neutron field of 252 Cf for 36.75 days and 0.3 mg of the sample is irradiated at the Pneumatic Irradiation Rabbit System (PIRS) built in the vertical thermal column of the ET-RR-2 reactor . The induced activities in the samples are measured using two high resolution f ray spectrometry systems (including two calibrated HPGe detectors). The kο standardization neutron activation analysis (kο-NAA) method was used to analyze the sample under investigation. Thermal to epithermal flux ratio fat the two irradiation positions are measured. The obtained results indicated that the values of the suspected heavy metals such as sodium, magnesium, potassium, manganese, arsenic, ruthenium and tantalum were higher than the background values, signifying accumulation of these heavy metals due to gold mining activities .The accuracy and precision of the method has been evaluated

  15. A 252Cf based nondestructive assay system for fissile material

    International Nuclear Information System (INIS)

    Menlove, H.O.; Crane, T.W.

    1978-01-01

    A modulated 252 Cf source assay system 'Shuffler' based on fast-or-thermal-neutron interrogation combined with delayed-neutron counting has been developed for the assay of fissile material. The 252 Cf neutron source is repetitively transferred from the interrogation position to a shielded position while the delayed neutrons are counted in a high efficiency 3 He neutron well-counter. For samples containing plutonium, this well-counter is also used in the passive coincidence mode to assay the effective 240 Pu content. The design of an optimized neutron tailoring assembly for fast-neutron interrogation using a Monte Carlo Neutron Computer Code is described. The Shuffler system has been applied to the assay of fuel pellets, inventory samples, irradiated fuel and plutonium mixed-oxide fuel. The system can assay samples with fissile contents from a few milligrams up to several kilograms using thermal-neutron interrogation for the low mass samples and fast-neutron interrogation for the high mass samples. Samples containing 235 U- 238 U, or 233 U-Th, or UO 2 -PuO 2 fuel mixtures have been assayed with the Shuffler system. (Auth.)

  16. Development of neutron induced prompt γ-ray spectroscopy system using 252Cf

    International Nuclear Information System (INIS)

    Park, Yong-Joon; Song, Byung-Chul; Jee, Kwang-Yong

    2003-01-01

    For the design and set-up of neutron induced prompt γ-ray spectroscopy system using 252 Cf neutron source, the effects of shielding and moderator materials have been examined. The 252 Cf source being used for TLD badge calibration in Korea Atomic Energy Research Institute was utilized for this preliminary experiment. The γ-ray background and prompt γ-ray spectrum of the sample containing Cl were measured using HPGe (GMX 69% relative efficiency) located at the inside of the system connected to notebook PC at the outside of the system (about 20 meter distance). The background activities of neutron and γ-rays were measured with neutron survey meter as well as γ-ray survey meters, respectively and the system was designed to minimize the activities. Prompt γ-ray spectrum was measured using γ-γ coincident system for reduce the background and the continuum spectrum. The optimum system was designed and set up using the experimental data obtained

  17. Measurement of Neutron Energy Spectrum Emitted by Cf-252 Source Using Time-of-Flight Method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Cheol Ho; Son, Jaebum; Kim, Tae Hoon; Lee, Sangmin; Kim, Yong-Kyun [Hanyang University, Seoul (Korea, Republic of)

    2016-10-15

    The techniques proposed to detect the neutrons usually require the detection of a secondary recoiling nucleus in a scintillator (or other type of detector) to indicate the rare collision of a neutron with a nucleus. This is the same basic technique, in this case detection of a recoil proton that was used by Chadwick in the 1930 s to discover and identify the neutron and determine its mass. It is primary technique still used today for detection of fast neutron, which typically involves the use of a hydrogen based organic plastic or liquid scintillator coupled to a photo-multiplier tube. The light output from such scintillators is a function of the cross section and nuclear kinematics of the n + nucleus collision. With the exception of deuterated scintillators, the scintillator signal does not necessarily produce a distinct peak in the scintillator spectrum directly related to the incident neutron energy. Instead neutron time-of-flight (TOF) often must be utilized to determine the neutron energy, which requires generation of a prompt start signal from the nuclear source emitting the neutrons. This method takes advantage of the high number of prompt gamma rays. The Time-of-Flight method was used to measure neutron energy spectrum emitted by the Cf-252 neutron source. Plastic scintillator that has a superior discrimination ability of neutron and gamma-ray was used as a stop signal detector and liquid scintillator was used as a stat signal detector. In experiment, neutron and gamma-ray spectrum was firstly measured and discriminated using the TOF method. Secondly, neutron energy spectrum was obtained through spectrum analysis. Equation of neutron energy spectrum that was emitted by Cf-252 source using the Gaussian fitting was obtained.

  18. Optimization of in situ prompt gamma-ray analysis using a HPGe-252Cf probe

    International Nuclear Information System (INIS)

    Chien Chung; Jiunnhsing Chao

    1991-01-01

    Application of in situ measurements by the neutron-induced prompt gamma-ray activation analysis (PGAA) technique to geochemical analysis and mineral survey have been investigated. An in situ survey of water pollutants by PGAA techniques was first proposed in the authors' previous study, where a 2.7-μg 252 Cf neutron source used in connection with a gamma-ray detecting system to determine water pollutants was described. In this paper the authors describe a modified detection probe designed and constructed to look for the optimum conditions of various-intensity 252 Cf neutron sources in measurement of some elements in lake water. Detecting efficiencies at high-energy regions and detection limits for elements commonly found in polluted lakes were evaluated and predicted to investigate the potential application of the probe for in situ measurements

  19. Radiation ulcers in patients with cancer of the tongue after /sup 252/Cf therapy

    Energy Technology Data Exchange (ETDEWEB)

    Galantseva, G.F.; Guseva, L.I.; Plichko, V.I. (Akademiya Meditsinskikh Nauk SSSR, Obninsk. Nauchno-Issledovatel' skij Inst. Meditsinskoj Radiologii)

    1984-01-01

    Interstitial therapy with /sup 252/Cf was conducted for 57 patients with cancer of the tongue. It was established that clinical course of radiation tungue ulcers after interstitial therapy with /sup 252/Cf doesn't differ sufficiently from the course of radiation injuries, occurring after ..gamma..-radiation application. Radiation ulcers are often observed in patients after the treatment of recurrent and residual tumors with /sup 252/Cf (in 33% of patients); the ulcers appeared in 15% of cases in patients after the treatment of initial ulcers tumors. Conservative treatment provide the cure of radiation tongue ulcers after interstitial therapy with /sup 252/Cf.

  20. Comparison Of 252Cf Time Correlated Induced Fisssion With AmLi Induced Fission On Fresh MTR Research Reactor Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Jay Prakash [Los Alamos National Laboratory

    2017-03-30

    The effective application of international safeguards to research reactors requires verification of spent fuel as well as fresh fuel. To accomplish this goal various nondestructive and destructive assay techniques have been developed in the US and around the world. The Advanced Experimental Fuel Counter (AEFC) is a nondestructive assay (NDA) system developed at Los Alamos National Laboratory (LANL) combining both neutron and gamma measurement capabilities. Since spent fuel assemblies are stored in water, the system was designed to be watertight to facilitate underwater measurements by inspectors. The AEFC is comprised of six 3He detectors as well as a shielded and collimated ion chamber. The 3He detectors are used for active and passive neutron coincidence counting while the ion chamber is used for gross gamma counting. Active coincidence measurement data is used to measure residual fissile mass, whereas the passive coincidence measurement data along with passive gamma measurement can provide information about burnup, cooling time, and initial enrichment. In the past, most of the active interrogation systems along with the AEFC used an AmLi neutron interrogation source. Owing to the difficulty in obtaining an AmLi source, a 252Cf spontaneous fission (SF) source was used during a 2014 field trail in Uzbekistan as an alternative. In this study, experiments were performed to calibrate the AEFC instrument and compare use of the 252Cf spontaneous fission source and the AmLi (α,n) neutron emission source. The 252Cf source spontaneously emits bursts of time-correlated prompt fission neutrons that thermalize in the water and induce fission in the fuel assembly. The induced fission (IF) neutrons are also time correlated resulting in more correlated neutron detections inside the 3He detector, which helps reduce the statistical errors in doubles when using the 252Cf interrogation source instead of

  1. Neutron gauging applications using a small 252Cf source

    International Nuclear Information System (INIS)

    Helf, S.

    1975-01-01

    The use of a small 252 Cf source, in the 3 to 4 μg range, for neutron gauging applications is described. Emphasis is placed on determination of low concentrations of moisture in homogeneous media, e.g., solvents, explosives, dried food products, etc. and on measurement of charge or fill weight of hydrogenous materials in sealed items, e.g., propellant in a cartridge case. Both moderation of fast neutrons and attenuation of thermalized neutrons have been explored for these applications. Parameters related to the attainment of optimum sensitivity for each method are discussed. Fast neutron moderation is superior for low level moisture measurement whereas thermal neutron attenuation is more sensitive for ''neutron weighing'' applications. Under optimum conditions, sensitivity for moisture measurement approaches 0.1 weight percent whereas ''neutron weighing'' can detect changes in hydrogeneous material content as little as a fraction of a gram. Examples are given for each technique. A number of different thermal neutron detectors are compared for neutron gauging measurements. A 6 LiI (Eu) scintillation detector is judged to be superior with regard to high thermal neutron detection efficiency and low fast neutron and gamma ray response. In this study, emphasis is placed on the use of simple, portable equipment easily adaptable to field or plant use and for on-line process or quality control. (U.S.)

  2. Evaluation of the 252Cf-source-driven neutron noise analysis method for measuring the subcriticality of LWR fuel storage casks

    International Nuclear Information System (INIS)

    Mihalczo, J.T.

    1987-01-01

    The 252 Cf-source-driven neutron noise analysis method was evaluated to determine if it could be used to measure the subcriticality of storage casks of burnt LWR fuel submerged in fuel storage pools, fully loaded and as they are being loaded. The motivation for this evaluation was that measurements of k/sub eff/ would provide the parameter most directly related to the criticality safety of storage cask configurations of LWR fuel and could allow proper credit for fuel burnup without reliance on calculations. This in turn could lead to more cost-effective cask designs. Evaluation of the method for this application was based on (1) experiments already completed at a critical experiments facility using arrays of PWR fuel pins typical of the size of storage cask configurations, (2) the existence of neutron detectors that can function in shipping cask environments, and (3) the ability to construct ionization chambers containing 252 Cf of adequate intensity for these measurements. These three considerations are discussed

  3. The fast neutron emission spectrum of 252-Cf

    International Nuclear Information System (INIS)

    Bensch, F.

    1979-07-01

    The aim of this work was a new measurement of the neutron emission spectrum of 252-Cf neutron standard sources as the IAEA is offering to users. The main feature was the application of gas-filled proton-recoil spectrometers and no TOF technique. The special interest of this document was in the temperature parameter of the Maxwellian distribution and in its relative deviations. In this connection, special measurements with high energy resolution were carried out in a search for fine structure neutron groups, which have been observed in some TOF measurements, but could not be reproduced during this measurement

  4. {sup 5}He ternary fission yields of {sup 252}Cf and {sup 235}U(n,f)

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, J. K. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Ramayya, A. V. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Hamilton, J. H. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Beyer, C. J. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Kormicki, J. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Zhang, X. Q. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Rodin, A. [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia (Russian Federation); Formichev, A. [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia (Russian Federation); Kliman, J. [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia (Russian Federation); Krupa, L. [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia (Russian Federation)] (and others)

    2000-04-01

    The relative {sup 4}He and {sup 5}He ternary fission yields were determined from a careful analysis of the energy distribution of {alpha} spectra from a new measurement with a {sup 252}Cf source and from published data on {sup 252}Cf and {sup 235}U(n,f). The kinetic energies of the {sup 5}He and {sup 4}He ternary particles were found to be approximately 11 and 16 MeV, respectively. {sup 5}He particles contribute 10-20 % to the total alpha yield with the remainder originating from {sup 4}He accompanied fission. (c) 2000 The American Physical Society.

  5. Measurements of gamma-ray dose from a moderated 252Cf source

    International Nuclear Information System (INIS)

    McDonald, J.C.; Griffith, R.V.; Plato, P.; Miklos, J.

    1983-06-01

    The gamma-ray dose fraction from a moderated 252 Cf source was determined by using three types of dosimetry systems. Measurements were carried out in air at a distance of 35 cm from the surface of the moderating sphere (50 cm from the source which is at the center of the sphere) to the geometrical center of each detector. The moderating sphere is 0.8-mm-thick stainless steel shell filled with D 2 O and covered with 0.5 mm of cadmium. Measurements were also carried out with instruments and dosimeters positioned at the surface of a 40 cm x 40 cm x 15 cm plexiglass irradiation phantom whose front surface was also 35 cm from the surface of the moderating sphere. A-150 tissue-equivalent (TE) plastic ionization chambers and a TE proportional counter (TEPC) were used to measure tissue dose, from which the neutron dose equivalent was computed. The ratio of gamma-ray dose to the neutron dose equivalent was determined by using a relatively neutron-insensitive Geiger-Mueller (GM) counter and thermoluminescent dosimeters (TLD). In addition, the event-size spectrum measured by the TEPC was also used to compute the gamma-ray dose fraction. The average value for the ratio of gamma-ray dose to neutron dose equivalent was found to be 0.18 with an uncertainty of about +-18%

  6. Subcriticality determination by a new time-domain correlation experiment with a 252Cf neutron source

    International Nuclear Information System (INIS)

    Nishina, K.; Yamane, Y.; Ishiguro, S.; Miyoshi, Y.; Suzaki, T.; Kobayahi, I.

    1985-01-01

    As a candidate for the on-site subcriticality-monitoring method, a new time-domain correlation experiment is proposed. Hinted by the Cf-252 detector method of Mihalczo, three covariances are taken between the count of three detectors; namely an ionization chamber with Cf-252 coating, and two He-3 proportional counters. A ratio Q is formed from the three quantities such that it does not depend either on detector efficiencies or counting gate duration T, and then related to reactivity. A formulation is given deriving a theoretical expression for this Q, with the effect of higher spatial modes included. Experiments were carried out with a loading at Tank-type Critical Assembly of Japan Atomic Energy Research Institute, which is a slightly-enriched, and light-water moderated system. With fundamental mode approximation adopted in the data processing, reasonable agreements are observed between the present method and the reactivity scale that has been calibrated by water-level variety. The possibility of the present method is to be investigated further beyond the range of 7$ reported

  7. Determination of disintegration half-life of 252Cf

    International Nuclear Information System (INIS)

    Chen Keliang; Liu Guoxing; Wang Sufang; Zheng Jiwen

    1991-01-01

    The follow-up measurements have been made by using a Si(Au) detector with small solid angle geometry for α disintegration of 252 Cf. The measured half-life of disintegration is 2.638 ± 0.009 year. This value is in accordance with other previous results

  8. Reactor production of 252Cf and transcurium isotopes

    International Nuclear Information System (INIS)

    Alexander, C.W.; Halperin, J.; Walker, R.L.; Bigelow, J.E.

    1990-01-01

    Berkelium, californium, einsteinium, and fermium are currently produced in the High Flux Isotope Reactor (HFIR) and recovered in the Radiochemical Engineering Development Center (REDC) at the Oak Ridge National Laboratory (ORNL). All the isotopes are used for research. In addition, 252 Cf, 253 Es, and 255 Fm have been considered or are used for industrial or medical applications. ORNL is the sole producer of these transcurium isotopes in the western world. A wide range of actinide samples were irradiated in special test assemblies at the Fast Flux Test Facility (FFTF) at Hanford, Washington. The purpose of the experiments was to evaluate the usefulness of the two-group flux model for transmutations in the special assemblies with an eventual goal of determining the feasibility of producing macro amounts of transcurium isotopes in the FFTF. Preliminary results from the production of 254g Es from 252 Cf will be discussed. 14 refs., 5 tabs

  9. Possibilities of activation analysis with 252Cf sources in the area of earth sciences and mining prospection

    International Nuclear Information System (INIS)

    Melky, Sami.

    1975-01-01

    The 252 Cf neutron activation experimental set-up is composed of four sources of 225μg each, symmetrically disposed with regard to the sample axis. This installation permits the irradiation of 5 to 40cm 3 of ores, so that the analysis is done on sample weighing about 100g. This method allows, not only the determination of major and minor constituents in the sample, but also the determination of some trace elements. The experimental sensitivity of some important elements are given in mining prospection and it is shown that direct gamma spectrometry after activation permits a fast and precise determination of many elements in ores [fr

  10. In situ prompt gamma-ray activation analysis of water pollutants using a shallow 252Cf-HPGe probe

    International Nuclear Information System (INIS)

    Chung Chien; Tseng Tzucheng

    1988-01-01

    A shallow 252 Cf-HPGe probe used for in situ prompt γ-ray activation of water pollutants is described. A 2.7 μg 252 Cf neutron source and a 10% HPGe detector are inserted into a waterproof stainless steel probe, which is designed to be submerged and recovered in field operation. A laboratory test is performed to obtain the neutron flux distribution and prompt γ-ray contribution to the HPGe detector counts from around the submerged probe. The concentrations of toxic cadmium and chlorine in water are determined in the prompt γ-ray spectrum. The detection limit of industrial pollutants and some improvements of the current design are discussed. (orig.)

  11. 252Cf-source-correlated transmission measurements for uranyl fluoride deposit in a 24-in.-OD process pipe

    International Nuclear Information System (INIS)

    Uckan, T.; Mihalczo, J.T.; Valentine, T.E.; Mullens, J.A.

    1998-01-01

    Characterization of a hydrated uranyl fluoride (UO 2 F 2 ·nH 2 O) deposit in a 17-ft-long, 24-in.-OD process pipe at the former Oak Ridge Gaseous Diffusion Plant was successfully performed by using 252 Cf-source-correlated time-of-flight (TOF) transmission measurements. These measurements of neutrons and gamma rays through the pipe from an external 2521 Cf fission source were used to measure the deposit profile and its distribution along the pipe, the hydration (or H/U), and the total uranium mass. The measurements were performed with a source in an ionization chamber on one side of the pipe and detectors on the other. Scanning the pipe vertically and horizontally produced a spatial and time-dependent radiograph of the deposit in which transmitted gamma rays and neutrons were separated in time. The cross-correlation function between the source and the detector was measured with the Nuclear Weapons Identification System. After correcting for pipe effects, the deposit thickness was determined from the transmitted neutrons and H/U from the gamma rays. Results were consistent with a later intrusive observation of the shape and the color of the deposit; i.e., the deposit was annular and was on the top of the pipe at some locations, demonstrating the usefulness of this method for deposit characterization

  12. RBE of Cf-252 neutrons as determined by its lethal, mutagenic, and cytogenetic effects on human cells

    International Nuclear Information System (INIS)

    Ban, Sadayuki

    1989-01-01

    To assess the biological effects of neutrons, a man-made spontaneously fissioning isotope, Cf-252, is useful as an experimental model to obtain basic biological data on mixed radiation of gamma-rays and neutrons. The paper describes the lethal effect of Cf-252 radiation on human skin fibroblasts, its lethal and mutagenic effect on HeLa MR cells, and the micronuclei inducing effect on human peripheral lymphocytes. Dose-survival responses of three fibroblast cell strains exposed to Cf-252 radiation are measured. Individual difference is larger than the experimental fluctuation. D 10 values of each strain are obtained from the linear model and linear-quadratic model. Though the dose rate of X-ray is higher than that of Cf-252 radiations, the mean value of RBE(n+γ) is simply obtained as 1.86+0.31 (RBE:relative biological effectiveness). RBE(n) of Cf-252 neutrons to high-dose-rate X-rays is 2.29. After X-ray irradiation, the survival curve of HeLa MR cells gives an extrapolation number of 3.6. It is 1.3 after Cf-252 irradiation. At 50% survival, RBE(n+γ) and RBE(n) are 2.05 and 2.6, respectively. At 10% survival they are 2.05 and 2.6. The mutation frequencies after X-ray irradiation showed a significant non-linear increase with dose. Those after Cf-252 irradiation increase linearly with dose. (N.K.)

  13. Decorporation of 241Am and 252Cf by Ca-DTPA from rat, Syrian and Chinese hamster

    International Nuclear Information System (INIS)

    Seidel, A.

    1977-01-01

    Retention and mobilization by Ca-DTPA of 241 Am and 252 Cf from rats, Syrian and Chinese hamsters are compared. Previous observations of a much longer residence time of actinides in hamsters liver than in rat liver are confirmed. Identical dose-effect functions were obtained for skeleton of rats and Syrian hamsters whereas 252 Cf removal from Chinese hamster skeleton was lower. The mobilization of 241 Am was lower than that of 252 Cf. With regard to species differences, qualitatively similar results were obtained for 241 Am as for 252 Cf. The results will be discussed with regard to the reduction by DTPA treatment of radiation risk in animal species with different biological half times of actinides in their livers. In this connection, attention will be paid to the usefulness of long-term DTPA treatment

  14. Experimental research on specific activity of 24Na using Chinese reference man phantom irradiated by 252Cf neutrons source

    International Nuclear Information System (INIS)

    Wang Yuexing; Yang Yifang; Lu Yongjie; Zhang Jianguo; Xing Hongchuan

    2011-01-01

    Objective: To investigate the specific activity of '2 4 Na per unit neutron fluence, A B/Φ ,in blood produced for Chinese reference man irradiated by 252 Cf neutron source,and to analyze the effects of scattering neutrons from ground,wall,and ceiling in irradiation site on it.Methods: A 252 Cf neutron source of 3×10 8 n/s and the anthropomorphic phantom were used for experiments. The phantom was made from 4 mm thick of outer covering by perspex and the liquid tissue-equivalent substitute in it. The data of phantom dimensions fit into Chinese reference man.The weight ratios of H, N, O and C in substitute equal from source to long axis of phantom were 1.1, 2.1, 3.1 and 4.1 m, respectively. Both the neutron source and the position of xiphisternum of the phantom were 1.6 m above the floor. Results: The average specific activity of 24 Na per unit neutron fluence was related to the irradiation-distances, d, and its maximum value, A B/ΦM , deduced by experimental data was about 1.85×10 -7 Bq·cm 2 ·g -1 . Conclusions: The A B/ΦM corresponds to that of phantom irradiated by plane-parallel beams, and the value is about more 3% than that by BOMAB phantom reported in literature. It has shown that floor-(wall-)scattered neutrons in irradiation site have significant contribution to the specific activity of 24 Na, but they contributed relatively little to the induced neutron doses. Consequently,using the specific activity of 24 Na for assessing accidental neutron doses received by an individual, the contribution of scattered neutrons in accident site will lead dose to be overestimated, and need to be correct. (authors)

  15. Transport-level description of the 252Cf-source method using the Langevin technique

    International Nuclear Information System (INIS)

    Stolle, A.M.; Akcasu, A.Z.

    1991-01-01

    The fluctuations in the neutron number density and detector outputs in a nuclear reactor can be analyzed conveniently by using the Langevin equation approach. This approach can be implemented at any level of approximation to describe the time evolution of the neutron population, from the most complete transport-level description to the very basic point reactor analysis of neutron number density fluctuations. In this summary, the complete space- and velocity-dependent transport-level formulation of the Langevin equation approach is applied to the analysis of the 252 Cf-source-driven noise analysis (CSDNA) method, an experimental technique developed by J.T. Mihalczo at Oak Ridge National Laboratory, which makes use of noise analysis to determine the reactivity of subcritical media. From this analysis, a theoretical expression for the subcritical multiplication factor is obtained that can then be used to interpret the experimental data. Results at the transport level are in complete agreement with an independent derivation performed by Sutton and Doub, who used the probability density method to interpret the CSDNA experiment, but differed from other expressions that have appeared in the literature

  16. Energy and angular distributions of neutrons from 252Cf spontaneous fission

    International Nuclear Information System (INIS)

    Vasil'ev, Yu.A.; Sidorov, L.V.; Vasil'eva, N.K.

    1982-01-01

    Some results from a first series of measurements of energy and angular distributions of neutrons from 252 Cf spontaneous fission using a spectrometer with high neutron detection efficiency, i.e. a 4π neutron time-of-flight spectrometer, were already presented. Subsequently, a second series of measurements was performed using a more sophisticated technique. For this second series, we used a more intense 252 Cf layer (25,000 spontaneous fissions per second). The angular resolution was improved by a factor of 2-3 by combining the hexahedral counter modules, placed at the same angle with respect to the direction of motion of the fragments, in new panoramic counters. The neutron counters were calibrated against the average 252 Cf neutron spectrum at several positions of the axis of the fragment detector with respect to the neutron counters. In the spectrum measurements and calibration work, the scattered neutron background was not determined theoretically, as in the first series of measurements, but experimentally using four extra scintillation counters with scatter cones; the counters were set up at 60 deg., 80 deg., 100 deg., and 120 deg. to the direction of separation of the fragments

  17. Resistive plate chamber neutron and gamma sensitivity measurement with a {sup 252}Cf source

    Energy Technology Data Exchange (ETDEWEB)

    Abbrescia, M.; Altieri, S.; Baratti, V.; Barnaba, O.; Belli, G.; Bruno, G.; Colaleo, A.; DeVecchi, C.; Guida, R. E-mail: roberto.guida@pv.infn.it; Iaselli, G.; Imbres, E.; Loddo, F.; Maggi, M.; Marangelli, B.; Musitelli, G.; Nardo, R.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Ratti, S.; Riccardi, C.; Romano, F.; Torre, P.; Vicini, A.; Vitulo, P.; Volpe, F

    2003-06-21

    A bakelite double gap Resistive Plate Chamber (RPC), operating in avalanche mode, has been exposed to the radiation emitted from a {sup 252}Cf source to measure its neutron and gamma sensitivity. One of the two gaps underwent the traditional electrodes surface coating with linseed oil. RPC signals were triggered by fission events detected using BaF{sub 2} scintillators. A Monte Carlo code, inside the GEANT 3.21 framework with MICAP interface, has been used to identify the gamma and neutron contributions to the total number of collected RPC signals. A neutron sensitivity of (0.63{+-}0.02)x10{sup -3} (average energy 2 MeV) and a gamma sensitivity of (14.0{+-}0.5)x10{sup -3} (average energy 1.5 MeV) have been measured in double gap mode. Measurements done in single gap mode have shown that both neutron and gamma sensitivity are independent of the oiling treatment.

  18. Monte Carlo design study of a moderated {sup 252}Cf source for in vivo neutron activation analysis of aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, D.G.; Natto, S.S.A.; Evans, C.J. [Swansea In Vivo Analysis and Cancer Research Group, Department of Physics, University of Wales, Swansea (United Kingdom); Ryde, S.J.S. [Swansea In Vivo Analysis and Cancer Research Group, Department of Medical Physics and Clinical Engineering, Singleton Hospital, Swansea (United Kingdom)

    1997-04-01

    The Monte Carlo computer code MCNP has been used to design a moderated 2{sup 52}Cf neutron source for in vivo neutron activation analysis of aluminium (Al) in the bones of the hand. The clinical motivation is the need to monitor l body burden in subjects with renal dysfunction, at risk of Al toxicity. The design involves the source positioned on the central axis at one end of a cylindrical deuterium oxide moderator. The moderator is surrounded by a graphite reflector, with the hand inserted at the end of the moderator opposing the source. For a 1 mg {sup 252}Cf source, 15 cm long x 20 cm radius moderator and 20 cm thick reflector, the estimated minimum detection limit is .5 mg Al for a 20 min irradiation, with an equivalent dose of 16.5 mSv to the hand. Increasing the moderator length and/or introducing a fast neutron filter (for example silicon) further reduces interference from fast-neutron-induced reactions on phosphorus in bone, at the expense of decreased fluence of the thermal neutrons which activate Al. Increased source strengths may be necessary to compensate for this decreased thermal fluence, or allow measurements to be made within an acceptable time limit for the comfort of the patient. (author)

  19. Neutron emission during acceleration of 252Cf fission fragments

    International Nuclear Information System (INIS)

    Batenkov, O.I.; Blinov, M.V.; Blinov, A.B.; Smirnov, S.N.

    1991-01-01

    We investigate neutron emission during acceleration of fission fragments in the process of spontaneous fission of 252 Cf. Experimental angular and energy distributions of neutrons are compared with the results of calculations of neutron evaporation during fragment acceleration. (author). 8 refs, 3 figs

  20. Application of modular neutron spectrometer to measure neutron spectra from fission of 252Cf

    International Nuclear Information System (INIS)

    Szeflinski, Z.; Osuch, S.; Popkiewicz, M.; Wilhelmi, Z.; Zelazny, Z.

    1996-01-01

    The neutron spectrometer MONA (Modular Neutron Array) and its test has been described. The spectrometers consist of eight BC-501A liquid scintillator detectors of BICRON which allow one to distinguish between the pulses from gamma quanta and neutrons using pulse shape discrimination (PSD) method. The electronic equipment for the PSD and the test result using the 252 Cf radioactive source are presented

  1. Burnout and gate rupture of power MOS transistors with fission fragments of 252Cf

    International Nuclear Information System (INIS)

    Tang Benqi; Wang Yanping; Geng Bin; Chen Xiaohua; He Chaohui; Yang Hailiang

    2000-01-01

    A study to determine the single event burnout (SEB) and single event gate rupture (SEGR) sensitivities of power MOSFET devices is carried out by exposure to fission fragments from 252 Cf source. The test method, test results, a description of observed burnout current waveforms and a discussion of a possible failure mechanism are presented. The test results include the observed dependence upon applied drain or gate to source bias and effect of external capacitors and limited resistors

  2. Test and evaluation results of the 252Cf shuffler at the Savannah River Plant

    International Nuclear Information System (INIS)

    Crane, T.W.

    1981-03-01

    The 252 Cf Shuffler, a nondestructive assay instrument employing californium neutron source irradiation and delayed-neutron counting, was developed for measuring 235 U content of scrap and waste items generated at the Savannah River Plant (SRP) reactor fuel fabrication facility. The scrap and waste items include high-purity uranium-aluminum alloy ingots as well as pieces of castings, saw and lathe chips from machining operations, low-purity items such as oxides of uranium or uranium intermixed with flux materials found in recovery operations, and materials not recoverable at SRP such as floor sweepings or residues from the uranium scrap recovery operation. The uranium contains about 60% 235 U with the remaining isotopes being 236 U, 238 U, and 234 U in descending order. The test and evaluation at SRP concluded that the accuracy, safety, reliability, and ease of use made the 252 Cf Shuffler a suitable instrument for routine use in an industrial, production-oriented plant

  3. Cross-sections of 197Au(n,α)198Au and 63Cu(n,α)64Cu induced by 252Cf neutrons

    International Nuclear Information System (INIS)

    Mandal, Ranjita; Sengupta, D.; Roy, Malobika; Naik, Mamta; Bhoraskar, V.N.

    2014-01-01

    Analytical work, employing nuclear techniques, is normally carried out through (n,α) reaction because of the availability of neutrons either from reactors or laboratory sources such as Sb-Be, Am-Be, Ra-Be, Po-Be, 252 Cf, etc. The laboratory neutron sources are though portable and adaptable to a particular experimental arrangement, suffer from the disadvantage of slow neutron yield (except 252 Cf). In this set up since the neutrons available are monoenergetic, it was thought appropriate to initiate a program to measure cross-sections of a few nuclear reactions which have practical applications. Earlier studies on cross-section measurement of the reaction 197 Au(n,α) 198 Au and 63 Cu(n,α) 64 Cu has been carried out using different sources, monitors and techniques

  4. Characterization of neutron spectra using sources of {sup 241}AmBe, {sup 238}PuBe e {sup 252}Cf moderated in water; Caracterização de espectros neutrônicos com fontes de {sup 241}AmBe, {sup 238}PuBe e {sup 252}Cf moderados em água

    Energy Technology Data Exchange (ETDEWEB)

    Gonçalves, A.S.; Silva, F.S.; Patrão, K.C.S.; Fonseca, E.S. da; Pereira, W.W., E-mail: angela.souzagon@gmail.com [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Laboratório de Metrologia de Nêutrons

    2017-07-01

    Recent studies have demonstrated the importance of characterizing the spectrum of neutron sources for various energies in order to make the understanding of neutron interaction closer to reality they work with. This work presents the determination of neutron energy flux from the source of {sup 241}AmBe (0.6 TBq), {sup 238}PuBe (1.8 TBq) and {sup 252}Cf (120 μg) free in the air and inserted into spheres of various diameters containing distilled water. The determination of the spectrum is based on the measurement and simulation by the Monte Carlo computational method, using the sources under study, with the Bonner multisphere spectrometer containing readings with the detector without sphere and covered with polyethylene balls of diameters: 5,08 cm (2 ″), 7.62 cm (3″), 12.70 cm (5 ″), 20.32 cm (8 ″), 25.40 cm (10 ″) and 30.48 cm (12 ″). It is sought to characterize a new moderate spectrum in water using the sources of {sup 241}AmBe, {sup 238}PuBe and {sup 252}Cf that may be useful for testing, calibration and irradiation of individual and area monitors for neutrons.

  5. Gamma-ray multiplicity measurement of the spontaneous fission decay of 252Cf in a segmented HPGe/BGO detector array

    Energy Technology Data Exchange (ETDEWEB)

    Bleuel, D L; Bernstein, L A; Burke, J T; Gibelin, J; Heffner, M D; Mintz, J; Norman, E B; Phair, L; Scielzo, N D; Sheets, S A; Snyderman, N J; Stoyer, M A; Wiedeking, M

    2008-04-23

    Coincident {gamma} rays from a {sup 252}Cf source were measured using an array of six segmented high-purity germanium (HPGe) Clover detectors each enclosed by 16 bismuth-germanate (BGO) detectors. The detectors were arranged in a cubic pattern around a 1 {micro}Ci {sup 252}Cf source to cover a large solid angle for {gamma}-ray measurement with a reasonable reconstruction of the multiplicity. Neutron multiplicity was determined in certain cases by identifying the prompt {gamma} rays from individual fission fragment pairs. Multiplicity distributions from previous experiments and theoretical models were convolved with the response function of the array and compared to the present results. These results suggest a {gamma}-ray multiplicity spectrum broader than previous measurements and models, and provide no evidence of correlation with neutron multiplicity.

  6. Evaluation of mass distribution data from 252Cf spontaneous fission

    International Nuclear Information System (INIS)

    Liu Tingjin

    2003-01-01

    The mass distribution data of 252 Cf spontaneous fission were evaluated based on 7 sets of available experimental data. The measured data were corrected for the standards and γ intensity used by using the new evaluated ones. The errors were made necessary adjusting. The evaluated experimental data were fitted with spline function without any restriction and with symmetric restriction. These two sets of fit data were recommended as reference data of the mass distribution of 252 Cf spontaneous fission. The errors of the recommended data were considerably reduced comparing with the measured ones. The light and heavy peaks are not completely symmetric. Also there are fine structures on the right side of the light peak at A=109-111 and left side of the heavy peak at A=137-139. These should be paid attention and studied further. (author)

  7. Thermal neutron imaging with rare-earth-ion-doped LiCaAlF6 scintillators and a sealed 252Cf source

    International Nuclear Information System (INIS)

    Kawaguchi, Noriaki; Yanagida, Takayuki; Fujimoto, Yutaka; Yokota, Yuui; Kamada, Kei; Fukuda, Kentaro; Suyama, Toshihisa; Watanabe, Kenichi; Yamazaki, Atsushi; Chani, Valery; Yoshikawa, Akira

    2011-01-01

    Thermal neutron imaging with Ce-doped LiCaAlF 6 crystals has been performed. The prototype of the neutron imager using a Ce-doped LiCaAlF 6 scintillating crystal and a position sensitive photomultiplier tube (PSPMT) which had 64 multi-channel anode was developed. The Ce-doped LiCaAlF 6 single crystal was grown by the Czochralski method. A plate with dimensions of a diameter of 50x2 mm 2 was cut from the grown crystal, polished, and optically coupled to PSPMT by silicone grease. The 252 Cf source ( 6 .

  8. Feasibility of subcriticality and NDA measurements for spent fuel by frequency analysis techniques with 252Cf

    International Nuclear Information System (INIS)

    Mihalczo, J.T.; Valentine, T.E.; Mattingly, J.K.

    1996-01-01

    The 252 Cf-source-driven frequency analysis method can be used for measuring the subcritical neutron multiplication factor of arrays of LWR fuel and as little as a single PWR fuel assembly. These measurements can be used to verify the criticality safety margins of spent LWR fuel configurations and thus could be a means of obtaining the information to justify burnup credit for spent LWR transportation/storage casks. In addition, the data can be used to validate calculational methods for criticality safety. These measurements provide parameters that have a higher sensitivity to changes in fissile mass than neutron multiplication factor and thus serve as a better test of calculational methods. The analysis have also shown that measurement of the cross power spectral density (CPSD) between detectors on one side of a single fuel assembly and an internal or external 252 Cf source driving the fission chain multiplication process can be used for nondestructive assay of fissile mass along the length of the assembly. This CPSD is a smooth function of fissile mass and does not depend on the varying inherent source in the fuel assembly and thus is ideal for fissile mass assay

  9. Identification of new neutron-rich rare-earth nuclei produced in /sup 252/Cf spontaneous fission

    CERN Document Server

    Greenwood, R C; Gehrke, R J; Meikrantz, D H

    1981-01-01

    A program of systematic study of the decay properties of neutron-rich rare-earth nuclei with 30 s252/Cf spontaneous fission, is currently underway using the Idaho ESOL (Elemental Separation On Line) Facility. The chemistry system used for the rare-earth elemental separations consists of two high-performance chromatography columns connected in series and coupled to the /sup 252 /Cf fission source via a helium gas-jet transport arrangement. The time delay for separation and initiation of gamma -ray counting with results which have been obtained to date with this system include the identification of a number of new neutron-rich rare-earth isotopes including /sup 155/Pm (t/sub 1/2/=48+or-4 s) and /sup 163/Gd (t/sub 1 /2/=68+or-3 s), in addition to 5.51 min /sup 158/Sm which was identified in an earlier series of experiments. (11 refs).

  10. Separation of 248Cm (III) from 252Cf (III) and its use in time resolved fluorescence spectroscopic (TRFS) studies

    International Nuclear Information System (INIS)

    Murali, M.S.; Nair, A.G.C.; Gujar, R.B.; Jain, A.; Tomar, B.S.; Godbole, S.V.; Reddy, A.V.R.; Manchanda, V.K.

    2008-07-01

    The present report gives a description of the methodology for the separation of 248 Cm(III) from decayed 252 Cf (III) waste solution. The waste solution was first assayed for 252 Cf content by neutron counting using a neutron well coincidence counter. The sample was subjected to the chemical separation of 248 Cm (III) from 252 Cf (III) following anion and cation exchange chromatography. The alpha spectrum of the separated curium fraction showed peaks due to 246 Cm and 248 Cm while the corresponding alpha spectrum of californium fraction showed 249,250,251,252 Cf. The gamma ray abundances of 249 Cf were determined with respect to its gamma rays of 387 keV and the data agreed well with that in literature. Separated Cm(III) was further characterized by recording its time resolved fluorescence spectrum (TRFS) in aqueous medium. (author)

  11. Study of biological effects of varying mixtures of Cf-252 and gamma radiation on the acute radiation syndromes: Relevance to clinical radiotherapy of radioresistant cancer

    International Nuclear Information System (INIS)

    Maruyama, Y.; Wierzbicki, J.; Feola, J.M.

    1993-01-01

    Data for the 30 day bone marrow syndrome (BM-50) and the 6-10 day gastrointestinal (GI-50) syndrome for a one and two fraction schedule and acute and low dose rate irradiation using pure and mixed Cf-252 and photon radiation are presented. The radiation of Cf-252 is a mixture of neutrons and gamma rays. Balb/c mice of both sexes were total body irradiated with acute Co-60, low dose rate Cs-137 and Cf-252 using a 1 x and 2 x schedule. For low linear energy transfer radiations of Co-60 or Cs-137 there was expected to be an increase in the dose to produce the gastrointestinal and bone marrow syndromes with minimal change for Cf-252 neutrons. The proportion of photons in the Cf-252 radiation field were further altered by mixing Cs-137 with the Cf-252 sources and mice were total body irradiated with different proportions of photons to determine the effect on the radiation syndromes. The effects of mixing Cf-252 neutrons with different proportions of photons on the syndromes was determined. There was increase in BM-50 and GI-50 doses with fractionated or low dose rate photon irradiations and the dose modifying factors were 1.3-1.4 for the GI syndrome and 1.2 for the bone marrow syndrome. For Cf-252 there was minimal fractionation effect for the GI-50 syndrome, which increased by 1.1 for x 1 vs. x 2 fractions; for the BM-50 syndrome it rose by a 1.1 factor. For LDR Cs-137 the dose for the GI-50 syndrome rose 2.2-fold. For mixed neutron-photon radiation of 0%, 15%, 35%, and 65% η/γ mixtures, the dose to produce the BM-50 and GI-50 endpoints dropped sharply from 0 to 35% neutrons and remained flat thereafter. For major tissues such as the bone marrow and GI tract, Cf-252 behaved as high linear energy transfer for mixtures of neutrons and gamma rays when the radiations were delivered simultaneously at the low dose rates studied. 35 refs., 3 figs., 2 tabs

  12. Californium-252: a remarkable versatile radioisotope

    International Nuclear Information System (INIS)

    Osborne-Lee, I.W.; Alexander, C.W.

    1995-01-01

    A product of the nuclear age, Californium-252 ( 252 Cf) has found many applications in medicine, scientific research, industry, and nuclear science education. Californium-252 is unique as a neutron source in that it provides a highly concentrated flux and extremely reliable neutron spectrum from a very small assembly. During the past 40 years, 252 Cf has been applied with great success to cancer therapy, neutron radiography of objects ranging from flowers to entire aircraft, startup sources for nuclear reactors, fission activation for quality analysis of all commercial nuclear fuel, and many other beneficial uses, some of which are now ready for further growth. Californium-252 is produced in the High Flux Isotope Reactor (HFIR) and processed in the Radiochemical Engineering Development Center (REDC), both of which are located at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The REDC/HFIR facility is virtually the sole supplier of 252 Cf in the western world and is the major supplier worldwide. Extensive exploitation of this product was made possible through the 252 Cf Market Evaluation Program, sponsored by the United States Department of Energy (DOE) [then the Atomic Energy Commission (AEC) and later the Energy Research and Development Administration (ERDA)]. This program included training series, demonstration centers, seminars, and a liberal loan policy for fabricated sources. The Market Evaluation Program was instituted, in part, to determine if large-quantity production capability was required at the Savannah River Laboratory (SRL). Because of the nature of the product and the means by which it is produced, 252 Cf can be produced only in government-owned facilities. It is evident at this time that the Oak Ridge research facility can meet present and projected near-term requirements. The production, shipment, and sales history of 252 Cf from ORNL is summarized herein

  13. Californium-252: a remarkable versatile radioisotope

    Energy Technology Data Exchange (ETDEWEB)

    Osborne-Lee, I.W.; Alexander, C.W.

    1995-10-10

    A product of the nuclear age, Californium-252 ({sup 252}Cf) has found many applications in medicine, scientific research, industry, and nuclear science education. Californium-252 is unique as a neutron source in that it provides a highly concentrated flux and extremely reliable neutron spectrum from a very small assembly. During the past 40 years, {sup 252}Cf has been applied with great success to cancer therapy, neutron radiography of objects ranging from flowers to entire aircraft, startup sources for nuclear reactors, fission activation for quality analysis of all commercial nuclear fuel, and many other beneficial uses, some of which are now ready for further growth. Californium-252 is produced in the High Flux Isotope Reactor (HFIR) and processed in the Radiochemical Engineering Development Center (REDC), both of which are located at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The REDC/HFIR facility is virtually the sole supplier of {sup 252}Cf in the western world and is the major supplier worldwide. Extensive exploitation of this product was made possible through the {sup 252}Cf Market Evaluation Program, sponsored by the United States Department of Energy (DOE) [then the Atomic Energy Commission (AEC) and later the Energy Research and Development Administration (ERDA)]. This program included training series, demonstration centers, seminars, and a liberal loan policy for fabricated sources. The Market Evaluation Program was instituted, in part, to determine if large-quantity production capability was required at the Savannah River Laboratory (SRL). Because of the nature of the product and the means by which it is produced, {sup 252}Cf can be produced only in government-owned facilities. It is evident at this time that the Oak Ridge research facility can meet present and projected near-term requirements. The production, shipment, and sales history of {sup 252}Cf from ORNL is summarized herein.

  14. Neutron beam experiments using nuclear research reactors: honoring the retirement of professor Bernard W. Wehring -II. 5. Testing Moderating Detection Systems with 252Cf-Based Reference Neutron Fields

    International Nuclear Information System (INIS)

    Hertel, Nolan E.; Sweezy, Jeremy; Sauber, Jeremiah S.; Vaughn, David; Cook, Andrew; Tays, Jeff; Ro, Tae-Ik

    2001-01-01

    In recent years, Georgia Institute of Technology (Georgia Tech) has been involved in a number of neutron dosimetry research projects. Several reference neutron fields are now available for such projects. They are all based on the use of a 252 Cf source. The source can be used by itself to create a reference un-moderated 252 Cf neutron field, or it can be placed inside several different moderating assemblies. The spectra created by placing the source inside these assemblies and the un-moderated source are employed to investigate detector and dosimeter responses. Currently, the set of moderators available includes a 30-cm diam cadmium-covered D 2 O spherical shell, a 30-cm-thick iron spherical shell, a 30-cm-diam polyethylene spherical shell, an 18.3-cm-thick tungsten spherical shell, a 16-cm-thick lead spherical shell, and a 9-cm-thick tantalum spherical shell. In addition, the 252 Cf source can be placed inside a neutron howitzer recently constructed at Georgia Tech. The howitzer is a WEP cylinder loaded with boron that has a 10.16-cm-diam cylindrical opening. When the source is placed in the cylindrical penetration of the howitzer, a neutron field ∼30 cm in diameter is created at a distance of 50 cm from the californium source. Over the last few years, Bonner sphere spectrometers using LiI(Eu) scintillators and LiF thermoluminescence dosimeters have been calibrated using this facility at Georgia Tech. Recently, the Neely Nuclear Research Center (NNRC) acquired an LB 6411 neutron probe (product of EG and G Berthold). This probe is designed to measure ambient dose equivalent in accordance with International Commission on Radiological Protection Publication 60 recommendations. It consists of a cylindrical 3 He proportional counter surrounded by a 25-cm-diam spherical polyethylene moderator. Its neutron response is optimized for dose rate measurements of neutrons between thermal energies and 20 MeV (Ref. 5). As a test of the instrument's ability to measure ambient

  15. Calibration of brachytherapy sources using ferrous sulphate-benzoic acid-xylenol orange dosimeter

    International Nuclear Information System (INIS)

    Madhvanath, U.; Kini, U.R.; Gupta, B.L.

    1976-01-01

    A solution containing 0.20 mM of ferrous ammonium sulphate, 5.0 mM benzoic acid and 0.20 mM xylenol orange in 0.05 N sulphuric acid was used for the calibration of 252 Cf, 137 Cs, 226 Ra and 60 Co needle sources. A known volume of this solution contained in a pyrex glass tube was irradiated with the source kept in a glass capillary at the centre of the solution. A few hours of irradiation were required for each needle and the absorbance of the solution was measured at 540 nm against the unirradiated solution. The accuracy of this method was found to be within a few percent and is particularly useful for 252 Cf sources as the neutron component of the source contributes significantly to the absorbance produced. (author)

  16. Design and construction of an explosive detection system by Tna methods, using 252Cf radioisotope source

    International Nuclear Information System (INIS)

    Tavakkoli Farsouli, A.

    1999-01-01

    Bombs concealed in luggage have threatened human life and property throughout the world's traffic. The plastic explosives could not checked by the X-ray detecting device. Thermal Neutron Activation method has been tested in the present work for non-destructive detection of explosives. A radioisotope neutron source 252 Cf and two gamma spectroscopy systems have been used as a tool to find explosives, regardless of the bomb's shape and the packing materials. The MCNP code has been used to design the neutronic section of the system. The measured thermal neutron fluxes by the gold foils in some location of the system were in good agreement with those data obtained by the MCNP code. Also, detection limits for nitrogen in various counting times were measured. The measurements show that the system is capable to detect 417 gr of HMX explosive material (158 gr nitrogen) by 10 minutes of counting time. To modify the system and to decrease the detection limits some opinions are given

  17. An absolute measurement of 252Cf prompt fission neutron spectrum at low energy range

    International Nuclear Information System (INIS)

    Lajtai, A.; Dyachenko, P.P.; Kutzaeva, L.S.; Kononov, V.N.; Androsenko, P.A.; Androsenko, A.A.

    1983-01-01

    Prompt neutron energy spectrum at low energies (25 keV 252 Cf spontaneous fission has been measured with a time-of-flight technique on a 30 cm flight-path. Ionization chamber and lithium-glass were used as fission fragment and neutron detectors, respectively. Lithium glasses of NE-912 (containing 6 Li) and of NE-913 (containing 7 Li) 45 mm in diameter and 9.5 mm in thickness have been employed alternatively, for the registration of fission neutrons and gammas. For the correct determination of the multiscattering effects - the main difficulty of the low energy neutron spectrum measurements - a special geometry for the neutron detector was used. Special attention was paid also to the determination of the absolute efficiency of the neutron detector. The real response function of the spectrometer was determined by a Monte-Carlo calculation. The scattering material content of the ionization chamber containing a 252 Cf source was minimized. As a result of this measurement a prompt fission neutron spectrum of Maxwell type with a T=1.42 MeV parameter was obtained at this low energy range. We did not find any neutron excess or irregularities over the Maxwellian. (author)

  18. Feasibility of fissile mass assay of spent nuclear fuel using 252Cf-source-driven frequency-analysis

    International Nuclear Information System (INIS)

    Mattingly, J.K.; Valentine, T.E.; Mihalczo, J.T.

    1996-01-01

    The feasibility was evaluated using MCNP-DSP, an analog Monte Carlo transport cod to simulate source-driven measurements. Models of an isolated Westinghouse 17x17 PWR fuel assembly in a 1500-ppM borated water storage pool were used. In the models, the fuel burnup profile was represented using seven axial burnup zones, each with isotopics estimated by the PDQ code. Four different fuel assemblies with average burnups from fresh to 32 GWd/MTU were modeled and analyzed. Analysis of the fuel assemblies was simulated by inducing fission in the fuel using a 252 Cf source adjacent to the assembly and correlating source fissions with the response of a bank of 3 He detectors adjacent to the assembly opposite the source. This analysis was performed at 7 different axial positions on each of the 4 assemblies, and the source-detector cross-spectrum signature was calculated for each of these 28 simulated measurements. The magnitude of the cross-spectrum signature follows a smooth upward trend with increasing fissile material ( 235 U and 239 Pu) content, and the signature is independent of the concentration of spontaneously fissioning isotopes (e.g., 244 Cm) and (α,n) sources. Furthermore, the cross-spectrum signature is highly sensitive to changes in fissile material content. This feasibility study indicated that the signature would increase ∼100% in response to an increase of only 0.1 g/cm 3 of fissile material

  19. The application of n-γ discrimination in 252Cf spontaneous neutron TOF spectra measurement

    International Nuclear Information System (INIS)

    Zhou Haojun; Zhang Yi; Li Jiansheng; Jin Yu; Wang Jie; Li Chunyuan

    2004-01-01

    The BC501 scintillator is used as a fast neutron detector. The effect that the pulse rise time method was used to discriminate γ from 252 Cf spontaneous neutron TOF spectra is studied in the experiment. A pulse rise time separation spectra of γ and 252 Cf spontaneous neuron upon 1 MeV is obtained, the n-γ separation function reaches to 4.6. When the result of pulse rise time separation coincides with the time-of-flight spectra in which the neutron energy is upon 0.5 MeV, 0.8 MeV and 1.0 MeV, comparing with the anticoincidence, γ was eliminated 99.90% at least. (authors)

  20. A fast neutron and dual-energy gamma-ray absorption method (NEUDEG) for investigating materials using a 252Cf source

    International Nuclear Information System (INIS)

    Bartle, C. Murray

    2014-01-01

    DEXA (dual-energy X-ray absorption) is widely used in airport scanners, industrial scanners and bone densitometers. DEXA determines the properties of materials by measuring the absorption differences of X-rays from a bremsstrahlung tube source with and without filtering. Filtering creates a beam with a higher mean energy, which causes lower material absorption. The absorption difference between measurements (those with a filter subtracted from those without a filter) is a positive number that increases with the effective atomic number of the material. In this paper, the concept of using a filter to create a dual beam and an absorption difference in materials is applied to radiation from a 252 Cf source, called NEUDEG (neutron and dual-energy gamma absorption). NEUDEG includes absorptions for fast neutrons as well as the dual photon beams and thus an incentive for developing the method is that, unlike DEXA, it is inherently sensitive to the hydrogen content of materials. In this paper, a model for the absorption difference and absorption sum in NEUDEG is presented using the combined gamma ray and fast neutron mass attenuation coefficients. Absorption differences can be either positive or negative in NEUDEG, increasing with increases in the effective atomic number and decreasing with increases in the hydrogen content. Sample sets of absorption difference curves are calculated for materials with typical gamma-ray and fast neutron mass attenuation coefficients. The model, which uses tabulated mass attenuated coefficients, agrees with experimental data for porcelain tiles and polyethylene sheets. The effects of “beam hardening” are also investigated. - Highlights: • Creation of a dual neutron/gamma beam from 252 Cf is described. • An absorption model is developed using mass attenuation coefficients. • A graphical method is used to show sample results from the model. • The model is successfully compared with experimental results. • The importance of

  1. A portable measurement system for subcriticality measurements by the CF-source-driven neutron noise analysis method

    International Nuclear Information System (INIS)

    Mihalczo, J.T.; Ragan, G.E.; Blakeman, E.D.

    1988-01-01

    A portable measurement system consisting of a personal computer used as a Fourier analyzer and three detection channels (with associated electronics that provide the signals to analog-to-digital (A/D) convertors) has been assembled to measure subcriticality by the /sup 252/Cf-source-driven neutron noise analysis method. The /sup 252/Cf-source-driven neutron noise analysis method for obtaining the subcritical neutron multiplication factor of a configuration of fissile material requires measurement of the frequency-dependent cross-power spectral density (CPSD), G/sub 23/(ω), between a pair of detectors (Nos. 2 and 3) located in or near the fissile material and CPSDs G/sub 12/(ω) and G/sub 13/(ω) between these same detectors and a source of neutrons emanating from an ionization chamber (No. 1) containing /sup 252/Cf, also positioned in or near the fissile material. The auto-power spectral density (APSD), G/sub 11/(ω), of the source is also required. A particular ratio of spectral densities, G/sub 12//sup */G/sub 13//G/sub 11/G/sub 23/ (/sup */ denotes complex conjugation), is then formed. This ratio is related to the subcritical neutron multiplication factor and is independent of detector efficiencies

  2. Prompt neutron energy spectrum for the spontaneous fission of Cf-252

    International Nuclear Information System (INIS)

    Blinov, M.V.; Boykov, G.S.; Vitenko, V.A.

    1985-06-01

    The prompt neutron spectrum for the spontaneous fission of Cf-252 has been measured in 0.01-10 MeV region by the time-of-flight technique using a fast ionization chamber with U-235 layers as the neutron detector. Numerical data for the spectrum are presented, with an error file. (author)

  3. Californium-252 sales and loans at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    King, L.J.

    1987-01-01

    The production and distribution in the United States of 252 Cf has recently been consolidated at the Oak Ridge National Laboratory (ORNL). The 252 Cf Industrial Sales/Loan Program and the 252 Cf University Load Program, which were formerly located at the Savannah River Plant (SRP), have been combined with the californium production and distribution activities of the Transuranium Element Production Program at ORNL. Californium-252 is sold to commercial users in the form of bulk californium oxide, palladium-californium alloy pellets, or alloy wires. Neutron source capsules, which are fabricated for loans to DOE or other US government agencies, are still available in all forms previously available. The consolidation of all 252 Cf distribution activities at the production site is expected to result in better service to users. In particular, customers for neutrons sources will be ale to select from a wider range of neutron source forms, including custom designs, through a single contact point

  4. Validation of IRDFF in 252Cf Standard and IRDF-2002 Reference Neutron Fields

    Directory of Open Access Journals (Sweden)

    Simakov Stanislav

    2016-01-01

    Full Text Available The results of validation of the latest release of International Reactor Dosimetry and Fusion File, IRDFF-1.03, in the standard 252Cf(s.f. and reference 235U(nth,f neutron benchmark fields are presented. The spectrum-averaged cross sections were shown to confirm IRDFF-1.03 in the 252Cf standard spontaneous fission spectrum; that was not the case for the current recommended spectra for 235U(nth,f. IRDFF was also validated in the spectra of the research reactor facilities ISNF, Sigma-Sigma and YAYOI, which are available in the IRDF-2002 collection. The ISNF facility was re-simulated to remove unphysical oscillations in the spectrum. IRDFF-1.03 was shown to reproduce reasonably well the spectrum-averaged data measured in these fields except for the case of YAYOI.

  5. 252Cf-source-driven neutron noise measurements of subcriticality for a slab tank containing aqueous Pu-U nitrate

    International Nuclear Information System (INIS)

    Mihalczo, J.T.; Blakeman, E.D.; Ragan, G.E.; Kryter, R.C.; Robinson, R.C.; Seino, H.

    1987-08-01

    In order to study nuclear criticality safety related to the development of fast breeder technology, 252 Cf-source-driven neutron noise analysis measurements were performed with a Pu-U nitrate solution in a slab tank of various heights and thickness varying 11.43 cm to 19.05 cm. The results and conclusions of these experiments are (1) a capability to measure the subcriticality of a multiplying system of slab geometry to a k/sub eff/ as low as 0.7 was demonstrated, (2) calculated neutron multiplication factors agreed with those from the experiments within ∼0.02, and (3) the applicability of the method for plutonium solution systems was demonstrated. This paper describes measurements in which the height of the slab was varied for a fixed thickness and the thickness varied for a fixed height, which are the first applications of this measurement method to slab geometry

  6. Design, Construction, and Modeling of a 252Cf Neutron Irradiator

    Directory of Open Access Journals (Sweden)

    Blake C. Anderson

    2016-01-01

    Full Text Available Neutron production methods are an integral part of research and analysis for an array of applications. This paper examines methods of neutron production, and the advantages of constructing a radioisotopic neutron irradiator assembly using 252Cf. Characteristic neutron behavior and cost-benefit comparative analysis between alternative modes of neutron production are also examined. The irradiator is described from initial conception to the finished design. MCNP modeling shows a total neutron flux of 3 × 105 n/(cm2·s in the irradiation chamber for a 25 μg source. Measurements of the gamma-ray and neutron dose rates near the external surface of the irradiator assembly are 120 μGy/h and 30 μSv/h, respectively, during irradiation. At completion of the project, total material, and labor costs remained below $50,000.

  7. Spectrum-averaged cross-section measurement of /sup 103/Rh(n,n)/sup 103m/Rh in the /sup 252/Cf fission neutron spectrum

    International Nuclear Information System (INIS)

    Lamaze, G.P.; Schima, F.J.; Eisenhauer, C.M.; Spiegel, V.

    1988-01-01

    Because of the similarity in energy dependence of the /sup 103/Rh(n,n') differential cross section to the kerma muscle response function for neutrons, rhodium may be useful as a neutron kerma monitor. In support of its use as a neutron monitor, the spectrum-averaged cross section σ-bar has been measured for a /sup 252/Cf fission neutron spectrum. Pairs of thin rhodium samples were irradiated on opposite sides of a thinly encapsulated /sup 252/Cf neutron source. The neutron emission rate of the /sup 252/Cf source was determined by the manganous sulfate (MnSO/sub 4/) bath technique. In this method, the californium source emission rate is determined by comparison to the known emission rate of NBS-I, a standard radium-beryllium neutron source. The neutron fluence incident on the rhodium samples is determined from the californium source strength, average sample-to-source distance, and the duration of the irradiation. Corrections are made for neutron scattering saturation of activity, and attenuation of the X rays by the sample during counting. The X rays were detected with an intrinsic germanium detector designed specifically for low-energy X-ray detection. The activity was not determined by absolute counting so that the final results depend on the value of P/sub Κx/, to total Κ X-ray emission probability. The results of five separate irradiations yield a value of σ-bar . P/sub Κx/ = 62.3 +- 1.9 mb. Using the most recently published value of P/sub Κx/ gives a value of σ-bar = 739 +- 22 mb. A discussion of systematic uncertainties is given

  8. Approaches for the generation of a covariance matrix for the Cf-252 fission-neutron spectrum

    International Nuclear Information System (INIS)

    Mannhart, W.

    1983-01-01

    After a brief retrospective glance is cast at the situation, the evaluation of the Cf-252 neutron spectrum with a complete covariance matrix based on the results of integral experiments is proposed. The different steps already taken in such an evaluation and work in progress are reviewed. It is shown that special attention should be given to the normalization of the neutron spectrum which must be reflected in the covariance matrix. The result of the least-squares adjustment procedure applied can easily be combined with the results of direct spectrum measurements and should be regarded as the first step in a new evaluation of the Cf-252 fission-neutron spectrum. (author)

  9. Simultaneous investigation of fission fragments and neutrons in 252Cf(s,f)

    International Nuclear Information System (INIS)

    Budtz-Joergensen, C.; Knitter, H.H.

    1986-01-01

    The gridded twin ion chamber developed at CBNM is used to measure the kinetic energy-, mass- and angular distributions of the fission fragments of 252 Cf in an advantageous 4π-geometry. Together with a neutron time-of-flight detector this experimental arrangement permits to measure the correlation between neutron emission, fragment angle, mass and energy in the spontaneous fission of 252 Cf. With the present experimental set-up a mass resolution for fission fragments of 0.5 a.m.u., an angular resolution of Δcosθ = 0.05 and a timing resolution of 0.7 ns FWHM were observed. Preliminary evaluations of the raw experimental data are presented for the fission fragment mass distribution, the average total kinetic energy and their variance as function of mass, the angular distribution between fragments and neutrons, the number of neutrons emitted per fragment as function of fragment mass, the average neutron emission energies as function of mass, and the prompt fission neutron spectrum averaged over all fragments. (author)

  10. Dosimetric evaluation of 252Cf beam for use in radiobiology studies at Hiroshima University

    International Nuclear Information System (INIS)

    Hoshi, M.; Takeoka, S.; Tsujimura, T.; Kuroda, T.; Kawami, M.; Sawada, S.

    1988-01-01

    This report provides reliable tissue kerma in free air data by characterising the 252 Cf irradiating system and by comparing three dosimetry methods, paired chambers (ICRU 1977, 1978), Fricke and thermoluminescence dosemeter. (author)

  11. Determination of the multiplication factor and its bias by the 252Cf-source technique: A method for code benchmarking with subcritical configurations

    International Nuclear Information System (INIS)

    Perez, R.B.; Valentine, T.E.; Mihalczo, J.T.; Mattingly, J.K.

    1997-01-01

    A brief discussion of the Cf-252 source driven method for subcritical measurements serves as an introduction to the concept and use of the spectral ratio, Γ. It has also been shown that the Monte Carlo calculation of spectral densities and effective multiplication factors have as a common denominator the transport propagator. This commonality follows from the fact that the Neumann series expansion of the propagator lends itself to the Monte Carlo method. On this basis a linear relationship between the spectral ratio and the effective multiplication factor has been shown. This relationship demonstrates the ability of subcritical measurements of the ratio of spectral densities to validate transport theory methods and cross sections

  12. Molecular weight determination of bisbenzyl-isoquinoline alkaloids by 252Cf-plasma desorption mass spectrometer

    International Nuclear Information System (INIS)

    Kohno, Hiroyuki; Tatsunami, Shinobu; Hiroi, Tomoko; Kouyama, Hiroshi; Taniguchi, Masashi; Yago, Nagasumi; Nakamura, Iwao

    1995-01-01

    Bisbenzylisoquinoline alkaloids of Stephania cepharantha have been used for various clinical purposes and recently reevaluated as stimulators of interleukin secretion in tissues. We analyzed molecular stuctures of bisbenzylisoquinoline alkaloids by determining their molecular weights using the 252 Cf-plasma desorption mass spectrometry (PDMS). The spectra were accumulated for 500 000 fission events. The acceleration voltage used here was 15 kV. Samples were analyzed using nitrocellulose-coated sample targets. Of the 5 alkaloids studied here, cepharanthine gave a main peak of molecular weight of 606.1 for the theoretical molecular weight of 606.7. The other minor peaks were considered to be demethylated fragment ions. 252 Cf-PDMS should be quite useful in studying structure, metabolism and pharmacokinetics of various drugs with extremely low coefficients of variation. (author)

  13. Power spectral density measurements with 252Cf for a light water moderated research reactor

    International Nuclear Information System (INIS)

    King, W.T.; Mihalczo, J.T.

    1979-01-01

    A method of determining the reactivity of far subcritical systems from neutron noise power spectral density measurements with 252 Cf has previously been tested in fast reactor critical assemblies: a mockup of the Fast Flux Test Facility reactor and a uranium metal sphere. Calculations indicated that this measurement was feasible for a pressurized water reactor (PWR). In order to evaluate the ability to perform these measurements with moderated reactors which have long prompt neutron lifetimes, measurements were performed with a small plate-type research reactor whose neutron lifetime (57 microseconds) was about a factor of three longer than that of a PWR and approx. 50% longer than that of a boiling water reactor. The results of the first measurements of power spectral densities with 252 Cf for a water moderated reactor are presented

  14. Radiological Characterization Technical Report on Californium-252 Sealed Source Transuranic Debris Waste for the Off-Site Source Recovery Project at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-04-24

    This document describes the development and approach for the radiological characterization of Cf-252 sealed sources for shipment to the Waste Isolation Pilot Plant. The report combines information on the nuclear material content of each individual source (mass or activity and date of manufacture) with information and data on the radionuclide distributions within the originating nuclear material. This approach allows for complete and accurate characterization of the waste container without the need to take additional measurements. The radionuclide uncertainties, developed from acceptable knowledge (AK) information regarding the source material, are applied to the summed activities in the drum. The AK information used in the characterization of Cf-252 sealed sources has been qualified by the peer review process, which has been reviewed and accepted by the Environmental Protection Agency.

  15. Calculation of neutron spectra for a 252Cf transport cask using ANISN running on a PC

    International Nuclear Information System (INIS)

    West, L.; Akin, B.P.; Lemley, E.C.

    1995-01-01

    Neutron spectra have been calculated using the ANISN one-dimensional discrete ordinates code for the case of a 152 Cf source in a transport cask of a particular design. All computations were done on personal computers (PCs) (mostly 486 models) with the ANISN-ORNL (486 version) computer code. With a source of 252 Cf fission neutrons, the neutron flux spectrum in the cask cannot be characterized as open-quotes moderated.close quotes Concern about an appropriate choice for the cross-section data set has led to a comparison, for this application, of three different cross-section libraries: DABL, HILO, and BUGLE-80. Although the cross-section sets were not originally designed for PC use, the libraries have been successfully employed for PC computations. Work with yet another data library, BUGLE-93, is incomplete at this stage. From neutron flux spectra on the surface of the cask, personnel dosimetric quantities (such as dose equivalent) have been determined for the DABL, HILO, and BUGLE-80 ANISN calculations

  16. Preliminary MCNP-POLIMI Simulations for the Evaluation of the ''Floor Effect'' Comparison of APSTNG and Cf Sources

    CERN Document Server

    Pozzi, S A

    2002-01-01

    The present simulations performed with the Monte Carlo code MCNP-POLIMI [1] have the scope of evaluating the associated-particle sealed tube neutron generator (APSTNG) for use as an interrogation source in the source-driven noise analysis method for the assay of nuclear materials. In the Nuclear Materials Identification System (NMIS) developed at the Oak Ridge National Laboratory, the time dependent cross-correlation of the timed neutron source and detector responses is one of the signatures acquired. Previous studies and measurements have demonstrated the sensitivity of this and other related signatures to fissile mass [2-3]. In a recent report [4], we outlined the advantages of the APSTNG interrogation source for use with NMIS when compared with the Cf-252 source. In particular, we showed that when the distance between the source and the sample and the sample and the detectors is large, the APSTNG source outperforms the Cf-252 in sensitivity to fissile mass. This is the case when performing measurements of ...

  17. Group Representation of the Prompt Fission Neutron Spectrum of {sup 252}Cf

    Energy Technology Data Exchange (ETDEWEB)

    Croft, S.; Miller, K. A. [Safeguards Science and Technology Group (N-1), Nuclear Nonproliferation Division, Los Alamos National Laboratory, Los Alamos(United States)

    2011-12-15

    We review the spectral representation used for the prompt fission neutron spectrum of 252Cf in the International Organization for Standardization document ISO 8529-1. We find corrections to Table A.2, the discrete group structure form, of this report are needed. We describe the approach to generating replacement values and provide a new tabulation.

  18. Dispersions and correlations of the distributions of products of 252Cf spontaneous fission

    International Nuclear Information System (INIS)

    Vidyakin, G.S.; Vyrodov, V.N.; Gurevich, I.I.; Kirillov, B.F.; Kozlov, Y.V.; Martem'yanov, V.P.; Sukhotin, S.V.; Tarasenkov, V.G.; Khakimov, S.K.

    1982-01-01

    We report the results of two experiments on study of the dispersions and correlations of the distributions of products of the spontaneous fission of 252 Cf. In each experiment about 10 8 fissions were recorded with simultaneous measurement of the number of neutrons produced and in one case the fragment kinetic energy and in the other case the energy of the prompt #betta# rays. The quantities obtained were the probabilities of production of a given number of neutrons per fission, the dispersions of the distributions of the number of neutrons produced and of the fragment kinetic energy, and the dependence of the average #betta#-ray energy and the average fragment kinetic energy on the number of neutrons produced. A calculation is made of the spectrum of the total energy carried away by fragments and neutrons, and its dispersion is determined. An estimate of the total energy release in the 252 Cf fission process is made

  19. An evaluation of the spontaneous fission prompt neutron spectrum of 252Cf

    International Nuclear Information System (INIS)

    Bojkov, G.S.; Yurevich, V.I.

    1987-01-01

    An evaluation of the spontaneous fission prompt neutron spectrum of 252 Cf from 1 keV to 20 MeV is described. Variance-covariance matrices for a number of recent experimental data sets were constructed and used to evaluate the neutron spectrum following a Bayesian procedure. The evaluated spectrum is compared with various experimental and theoretical representations. (author)

  20. A new type-B cask design for transporting 252Cf

    International Nuclear Information System (INIS)

    Simmons, C.M.

    2000-01-01

    A project to design, certify, and build a new US Department of Energy (DOE) Type B container for transporting >5 mg of 252 Cf is more than halfway to completion. This project was necessitated by the fact that the existing Oak Ridge National Laboratory (ORNL) Type B containers were designed and built many years ago and thus do not have the records and supporting data that current regulations require. Once the new cask is available, it will replace the existing Type B containers. The cask design is driven by the unique properties of 252 Cf, which is a very intense spontaneous fission neutron source and necessitates a large amount of neutron shielding. The cask is designed to contain up to 60 mg of 252 Cf in the form of californium oxide or californium oxysulfate, in pellet, wire, or sintered material forms that are sealed inside small special-form capsules. The new cask will be capable of all modes of transport (land, sea, and air). The ORNL team, composed of technical and purchasing personnel and using rigorous selection criteria, chose NAC, International (NAC), as the subcontractor for the project. In January 1997, NAC started work on developing the conceptual design and performing the analyses. The original design concept was for a tungsten alloy gamma shield surrounded by two concentric shells of NS-4-FR neutron shield material. A visit to US Nuclear Regulatory Commission (NRC) regulators in November 1997 to present the conceptual design for their comments resulted in a design modification when the question of potential straight-line cracking in the NS-4-FR neutron shield material arose. NAC's modified design includes offset, wedgelike segments of the neutron shield material. The new geometry eliminates concerns about straight-line cracking but increases the weight of the packaging and makes the fabrication more complex. NAC has now completed the cask design and performed the analyses (shielding, structural, thermal, etc.) necessary to certify the cask. The cask

  1. Mass spectrometry with ionization induced by 252Cf fission fragments

    International Nuclear Information System (INIS)

    Sysoev, A.A.; Artaev, V.B.

    1991-01-01

    The review deals with mass-spectrometry with ionization induced by 252 Cf fission fragments. Equipment and technique of the analysis, analytic possibilities of the method are considered. The method permits to determine molecular masses of large nonvolatile biological molecules. The method is practically nondestructive, it possesses a high resolution over the depth and surface, which permits to use it for the analysis of surface of semiconductors, dielectrics, catalysts, for the study of formation kinetics of complex unstable molecules on the surface

  2. The use of polyimide foils to prevent contamination from self-sputtering of {sup 252}Cf deposits in high-accuracy fission counting

    Energy Technology Data Exchange (ETDEWEB)

    Gilliam, David M. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)], E-mail: david.gilliam@nist.gov; Yue, Andrew [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN (United States); Scott Dewey, M. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)

    2008-06-01

    It is demonstrated that a thin polyimide foil can be employed to prevent contamination from the self-sputtering of a {sup 252}Cf source under vacuum, with small energy loss of the emitted fission fragments, with very small effect on the efficiency of counting the fission fragments, and with a long lifetime of the plastic foils.

  3. Correlation studies of neutron multiplicities in the 252Cf spontaneous fission

    International Nuclear Information System (INIS)

    Alkhazov, I.D.; Dmitriev, V.D.; Kovalenko, S.S.; Kuznetsov, A.V.; Malkin, L.Z.; Petrzhak, K.A.; Petrov, B.F.; Shpakov, V.I.

    1988-01-01

    Correlations between the numbers of neutrons emitted by the 252 Cf spontaneous fission fragments have been studied as a function of the fragment mass and total kinetic energy. Behaviour of the neutron number dispersions and covariances was studied for the region of symmetric fission. Parameters of the complementary fragment excitation energy distribution (mean values, dispersions, covariances) were determined. Various factors describing correlations between the complementary fragment excitation energies are considered

  4. The legacy of Cf-252 operations at Savannah River Technology Center: Continuous releases of radioiodine to the atmosphere

    International Nuclear Information System (INIS)

    Kantelo, M.V.; Crandall, B.S.

    1992-01-01

    The iodine isotopes I-132, 1-133, I-134, and I-135, which have half-lives ranging from 53 minutes to 21 hours, are measured in the atmospheric effluent from the Savannah River Technology Center (SRTC) at the Savannah River Site (SRS) near Aiken, South Carolina. SRS is operated by Westinghouse Savannah River Company for the US Department of Energy (DOE). The isotopes' release rates range from 10 to 300 microcuries per week compared to the rate. The resulting annual dose from all iodine isotopes is minor; it comprises 0.01 percent of the total offsite dose due to atmospheric releases from SRS in 1990. Circumstantial evidence indicates the radioiodine originates from traces of unencapsulated Cf-252. The determination that spontaneous fission of Cf-252 is the source of the radioiodine has several ramifications. Radioactive fission-product isotopes of the noble gas elements krypton and xenon must also be released. Noble gases are more volatile and mobile than iodine. Also, the released iodine isotopes decay to xenon isotopes. The noble gases decay to non-gaseous elements that are transported along with radioiodine to the terrestrial environment by deposition from the SRTC plume. Only Sr-89 is believed to accumulate sufficiently in the environment to approach detectable levels. Given similar conditions in earlier years, releases of short-lived radioiodine have occurred undetected in routine monitoring since the early 1970s. Release rates 20 years ago would have been 200 times greater than current release rates. This report documents preliminary experiments conducted by SRTC and Environmental Monitoring Section (EMS) scientists. The release process and the environmental impact of fission products from Cf-252 should be thoroughly researched

  5. Relative biological effectiveness (R.B.E.) of Cf-252 vs. acute Co-60 and low dose rate Cs-137 irradiation by spleen weight loss

    International Nuclear Information System (INIS)

    Maruyama, Y.; Feola, J.M.; Magura, C.; Beach, J.L.

    1986-01-01

    R.B.E. of Cf-252 on lymphoid tissue was assessed by radiation study of spleen weight loss following acute Co-60, and low dose rate (L.D.R.) Cs-137 and Cf-252 irradiations. Acute Co-60 and L.D.R. Cs-137 dose-response followed two component exponential curves with a 1.3-fold greater effect of L.D.R. Cs-137 vs. acute Co-60 on the first slope and 1.9-fold greater effect for the 2nd slope. L.D.R. Cf-252 response was 1.3 x greater than acute Co-60 but was 1.0 vs. L.D.R. Cs-137 for the first slope indicating a similar effect of Cf-252 mixed neutron/gamma radiation to L.D.R. gamma radiation in producing spleen shrinkage. There was no effect of different sequences and schedules of mixing acute Co-60 with Cf-252 irradiation observed by endogenous CFU-S survival. The R.B.E. of 1.0 - 1.9 indicates that lymphohemopoietic in vivo, presumably well oxygenated, does not respond acutely or as sensitively as hypoxic tumor where R.B.E. is 5 - 7. (author)

  6. Shielding of radiation fields generated by 252Cf in a concrete maze. Part 2 -- Simulation

    International Nuclear Information System (INIS)

    Fasso, A.; Ipe, N.E.; Reyna, A.

    1998-03-01

    A streaming experiment performed in a concrete maze of shape and size typical of a radiotherapy room was simulated with the Monte Carlo program FLUKA. The purpose of the calculation was to test the performance of the code in the low energy neutron range, and at the same time to provide additional information which could help in optimizing shielding of medical facilities. Instrument responses were calculated at different maze locations for several experimental configurations and were compared with measurements. In addition, neutron and gamma fluence, ambient dose equivalent and effective dose were calculated at the same positions. Both sources used in the experiment, namely a bare 252 Cf source and one shielded by a tungsten shell 5 cm thick, were considered in the simulation

  7. Investigation of short-living fission products from the spontaneous fission of Cf-252

    International Nuclear Information System (INIS)

    Klonk, H.

    1976-01-01

    In this paper, a method of separating and measuring fission products of Cf-252 is presented. The measurement was achieved by means of γ-spectrometry and thus provides a quantitative analysis with a good separation of the fission products with respect to both atomic number Z and mass number A. The separation of the fission products from the fission source was achieved by means of solid traps. An automatic changing apparatus made it possible to keep irradiation and measuring times short, so even very short-lived fission products could be registered. The quantitative evaluation of primary fission products was made possible by correction according to Bateman equations. With that, the yields of single nuclides and the dispersion of charge can be determined. (orig./WL) [de

  8. 4π-spectrometer technique for measurements of secondary neutron average number in nuclear fission by 252Cf neutrons

    International Nuclear Information System (INIS)

    Vasil'ev, Yu.A.; Barashkov, Yu.A.; Golovanov, O.A.; Sidorov, L.V.

    1977-01-01

    A method for determining the average number of secondary neutrons anti ν produced in nuclear fission by the neutrons of the 252 Cf fission spectra by means of a 4π time-of-flight spectrometer is described. Layers of 252 Cf and an isotope studied are placed close to each other; if the isotope layer density is 1 mg/cm 2 probability of its fission is about 10 -5 per one spontaneous fission of californium. Fission fragments of 252 Cf and the isotope investigated have been detected by two surface-barrier counters with an efficiency close to 100%. The layers and the counters are situated in a measuring chamber placed in the center of the 4π time-of-flight spectrometer. The latter is utilized as a neutron counter because of its fast response. The method has been verified by carrying out measurements for 235 U and 239 Pu. A comparison of the experimental and calculated results shows that the method suggested can apply to determine the number of secondary neutrons in fission of isotopes that have not been investigated yet

  9. Project 252Cf-D2O. The multisphere system of neutron dosimetry and spectrometry (M.S.-N.D.S.). Studies of applications to health physics

    International Nuclear Information System (INIS)

    Zaborowski, H.L.

    1976-10-01

    The project 252 Cf-D 2 O is articulated upon the utilization of a 200μg nominal 252 Cf spontaneous neutron fission source, used bare and under D 2 O spherical moderators, giving leakage neutron spectra experimentally known and/or calculated. This project has for objective the applications of those sources to Health Physics, in dosimetry (calibration of ''rad'' and ''rem-meters'') and in spectrometry, associated with the experimental system of measurements made by the generalization of the BONNER Spheres, known as ''the Multisphere System''. This communication describes the normalization method used and the results obtained leading to the adoption of a reference matrix called ''the Log-Normal Multisphere Matrix'' (LN-MM) giving the energies response functions of the generalized system for all the spheres diameters between 40 and 400 millimeters and for all the energies between 0.4eV and 15MeV [fr

  10. Correlated spins of complementary fragment pairs in the spontaneous fission of 252Cf

    International Nuclear Information System (INIS)

    Smith, A. G.; Simpson, G. S.; Billowes, J.; Dagnall, P. J.; Durell, J. L.; Freeman, S. J.; Leddy, M.; Phillips, W. R.; Roach, A. A.; Smith, J. F.

    1999-01-01

    A study of the γ-ray decay of low-lying excited states in fragments produced in the spontaneous fission of 252 Cf has revealed a significant correlation between the angles of emission of the 2 1 + →0 1 + transitions of complementary fragment pairs. Calculations of the amount of dealignment that is needed to reproduce the measured a 2 values, and a comparison with the results of previous fragment-γ angular distribution measurements, suggests that at scission there may be significant population of m≠0 substates associated with the projection of the fragment spin vector on the fission axis. Fragments from the spontaneous fission of 248 Cm emit 2 1 + →0 1 + γ rays that show markedly reduced interfragment correlations, suggesting that either a larger role is played by the relative angular momentum of the fragments, or that the dealignment introduced by the neutron emission and statistical γ decay to the 2 1 + state is larger in 248 Cm than 252 Cf fission. (c) 1999 The American Physical Society

  11. Determination of the average number of neutrons per fission event for californium-252

    International Nuclear Information System (INIS)

    Aleksandrov, B.M.; Belov, L.M.; Drapchinskij, L.V.

    1982-01-01

    By means of a separate determination of neutron yields and fission event rates, the value of #betta#-bar( 252 Cf) has been measured for a series of new high-purity sources. The improved quality of the source active layers has reduced the error in determining the fission rate to 0.35%. The value obtained for #betta#-bar( 252 Cf) is 3.747+-0.036. A description is given of the design and the parameters of a spherical manganese bath in which the work on refining the value of #betta#-bar( 252 Cf) will be continued. (author)

  12. True ternary fission of 252Cf

    International Nuclear Information System (INIS)

    Vijayaraghavan, K.R.; Balasubramaniam, M.; Oertzen, W. von

    2014-01-01

    Splitting of heavy radioactive nucleus into three fragments is known as ternary fission. If the size of the fragments are almost equal it is referred to as true ternary fission. Recently, Yu. V. Pyatkov et al observed/reported the experimental observation of true ternary fission in 252 Cf. In this work, the possibilities of different true ternary fission modes of 252 Cf through potential energy surface (PES) calculations based on three cluster model (TCM) are discussed. In TCM a condition on the mass numbers of the fission fragments is implied as A 1 ≥ A 2 ≥ A 3 in order to avoid repetition of combinations. Due to this condition, the values of Z 3 vary from 0 to 36 and Z 2 vary from 16 to 51. Of the different pairs having similar (Z 2 , Z 3 ) with different potential energy, a pair possessing minimum potential energy is chosen. Thus identified favourable combinations are plotted. For the PES calculations the arrangement of the fragments is considered in the order of A 1 +A 2 +A 3 . i.e. the heavy and the lightest fragments are kept at the ends. It is seen that the deepest minimum in the PES occurs for Z 3 =2 labelled as (Z 2 ; 2) indicating He accompanied breakup as the most favourable one. Of which, the breakup with Z 2 around 46 to 48 is the least (shown by dashed (Z 1 = 50) and dotted (Z 1 = 52) lines indicating a constant Z 1 value). The other notable minima in the PES are labelled and they correspond to the (Z 2 , Z 3 ) pairs viz., (20, 20), (28, 20), (28, 28) and (32, 32). Of these four minima, the first three are associated with the magic numbers 20 and 28. For Z 3 =20, there are two minimums at (20,20) and (28,20) among them (28,20) is the lowest minimum through which the minimum-path passes, and it is the ternary decay observed by Yu. V. Pyatkov et al. The fourth minima is the most interesting due to the fact that it corresponds to true ternary fission mode with Z 2 =32, Z 3 =32 and Z 1 =34. The minimum potential energy path also goes through this true

  13. Shielding of radiation fields generated by {sup 252}Cf in a concrete maze. Part 2 -- Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Fasso, A.; Ipe, N.E.; Reyna, A. [Stanford Univ., CA (US). Stanford Linear Accelerator Center; McCall, R.C. [McCall Associates, Woodside, CA (US)

    1998-03-01

    A streaming experiment performed in a concrete maze of shape and size typical of a radiotherapy room was simulated with the Monte Carlo program FLUKA. The purpose of the calculation was to test the performance of the code in the low energy neutron range, and at the same time to provide additional information which could help in optimizing shielding of medical facilities. Instrument responses were calculated at different maze locations for several experimental configurations and were compared with measurements. In addition, neutron and gamma fluence, ambient dose equivalent and effective dose were calculated at the same positions. Both sources used in the experiment, namely a bare {sup 252}Cf source and one shielded by a tungsten shell 5 cm thick, were considered in the simulation.

  14. 10 CFR 35.406 - Brachytherapy sources accountability.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Brachytherapy sources accountability. 35.406 Section 35....406 Brachytherapy sources accountability. (a) A licensee shall maintain accountability at all times... area. (c) A licensee shall maintain a record of the brachytherapy source accountability in accordance...

  15. High sensitivity isotope analysis with a 252Cf--235U fueled subcritical multiplier and low background photon detector systems

    International Nuclear Information System (INIS)

    Wogman, N.A.; Rieck, H.G. Jr.; Laul, J.C.; MacMurdo, K.W.

    1976-09-01

    A 252 Cf activation analysis facility has been developed for routine multielement analysis of a wide variety of solid and liquid samples. The facility contains six sources of 252 Cf totaling slightly over 100 mg. These sources are placed in a 93 percent 235 U-enriched uranium core which is subcritical with a K effective of 0.985 (multiplication factor of 66). The system produces a thermal flux on the order of 10 +1 neutrons per square centimeter per second. A pneumatic rabbit system permits automatic irradiation, decay, and counting regimes to be performed unattended on the samples. The activated isotopes are analyzed through their photon emissions with state-of-the-art intrinsic Ge detectors, Ge(Li) detectors, and NaI(Tl) multidimensional gamma ray spectrometers. High efficiency (25 percent), low background, anticoincidence shielded Ge(Li) gamma ray detector systems have been constructed to provide the lowest possible background, yet maintain a peak to Compton ratio of greater than 1000 to 1. The multidimensional gamma ray spectrometer systems are composed of 23 cm diameter x 20 cm thick NaI(Tl) crystals surrounded by NaI(Tl) anticoincidence shields. The detection limits for over 65 elements have been determined for this system. Over 40 elements are detectable at the 1 part per million level at a precision of +-10 percent

  16. Importance of the elemental composition in brachytherapy with neutrons

    International Nuclear Information System (INIS)

    Paredes G, L.; Balcazar G, M.; Azorin N, J.; Francois L, J.L.

    2004-01-01

    An analysis is presented of as the small differences that exist in the elementary composition of the wicked tumors, healthy fabrics and some material substitutes of fabric employees in dosimetry, they generate variations in the value of the kerma coefficient and consequently in the absorbed dose of neutrons in the interval 11 eV to 29 MeV. These differences make that the coefficient of kerma of neutrons average for the considered wicked tumors, be between 6% and 7% smaller that the coefficient of kerma of neutrons average for soft fabric, in the interval of interest in therapy with quick neutrons. These results have a special importance during the process of planning of brachytherapy treatments with sources of 252 Cf, to optimize and to individualize the treatments to the patients. (Author)

  17. A portable measurement system for subcriticality measurements by the Cf-source-driven neutron noise analysis method

    International Nuclear Information System (INIS)

    Mihalczo, J.T.; Ragan, G.E.; Blakeman, E.D.

    1987-01-01

    A portable measurement system consisting of a personal computer used as a Fourier analyzer and three detection channels (with associated electronics that provide the signals to analog-to-digital (A/D) convertors) has been assembled to measure subcriticality by the 252 Cf-source-driven neutron noise analysis method. 8 refs

  18. Investigation of the far asymmetric region in 252Cf(sf)

    International Nuclear Information System (INIS)

    Hambsch, F.-J.; Oberstedt, S.

    1997-01-01

    A twin Frisch-gridded ionization chamber has been used to measure the fission fragment mass, kinetic-energy and angular correlations for 252 Cf(sf). In total 2.5 x 10 8 events were collected. The focus was in the far asymmetric mass region, where enhancements in the yield had been found earlier. It could be shown, that these findings are due to false events, coming from either close geometries not properly taking into account the angular-dependent energy loss in the sample and backing, from a too large angular cone selected in case of studies employing ionization chambers, or even from poor target qualities. (orig.)

  19. Trajectory calculations for the ternary cold fission of 252Cf

    International Nuclear Information System (INIS)

    Misicu, S.

    1998-01-01

    We compute the final kinetic energies of the fragments emitted in the light charged particle accompanied by cold fission of 252 Cf taking into account the deformation and the finite-size effects of the fragments and integrating the equations of motion for a three-body system subjected only to Coulomb forces. The initial conditions for the trajectory calculations were derived in the framework of a deformed cluster model which includes also the effect due to the absorbative nuclear part. Although the distributions of initial kinetic energies are rather broad we show that in cold fission the initial conditions can be better determined than in the usual spontaneous fission

  20. High energy {gamma} emission in the spontaneous fission of {sup 252}Cf; Emission {gamma} de grande energie dans la fission spontanee de {sup 252}Cf

    Energy Technology Data Exchange (ETDEWEB)

    Badimon, C.; Barreau, G.; Doan, T.P.; Pedemay, G. [Centre d`Etudes Nucleaires, Bordeaux-1 Univ., 33 Gradignan (France); Gautherin, C.; Houry, M.; Korten, W.; Le Coz, Y.; Lucas, R.; Thiesen, Ch. [Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee, CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France); Belier, G.; Meot, M.V. [CEA Centre d`Etudes de Bruyeres-le-Chatel, 91 (France); Astier, A.; Ducroux, L.; Meyer, M.; Redon, N. [Inst.de Physique Nucleaire, Lyon-1 Univ., 69 - Villeurbanne (France)

    1997-06-01

    The prompt {gamma} emission in the spontaneous fission of {sup 252}Cf is characterized by an energy spectrum which extends up to 20 MeV. It was established that the spectrum presents in the neighbourhood of symmetric fission an intensity bump in the 3-8 MeV {gamma} energy interval. The origin of this phenomenon is still not well understood, so that it was found interesting to carry out new measurements. The spectrum of the {gamma} rays emitted in spontaneous fission of {sup 252}Cf has been measurement in the EUROGAM II multidetector using photovoltaic cells to detect fragments. The aim of the experiment was to investigate the {gamma} yield enhancement which appears for mass fragment ratio near 132/120. This enhancement was found to be composed of two peaks located at 4 MeV and 5.5 MeV respectively. The results obtained confirm the intensity bound in the 3-8 MeV region but this augmentation reaches the maximum when the heavy fragment is near the mass 132. Beyond mass 140 the phenomenon diminish and the {gamma} spectrum regains the behaviour expected for a statistic emission. The additional structure at 5.5 MeV does not vary with excitation energy while the excitation function of the 4 MeV structure is more structured and presents a maximum when the excitation energy is near 8 MeV. It is likely that all or part of this observed phenomenon is due to a particular excitation mode of this isotope associated for instance with a low energy dipole resonance. A theoretical study of this collective effect is under way 3 refs.

  1. Investigation of the characteristics of 252Cf-detectors

    International Nuclear Information System (INIS)

    Karlsson, Erik

    2004-12-01

    In the first chapter the characteristic behaviors of two Cf detectors have been investigated by performing pilot measurements. The detector with the stronger source gives an unstable signal with a low signal/noise ratio. Therefore this detector has not been further investigated. The ionization chamber reacts on both fission products and alpha decay. An energy experiment showed that there were large difficulties to separate those decays. A plastic scintillator, which reacts on both photons and neutrons, was used for neutron detection. Energy spectrums were performed and the result showed that it is difficult to set an energy threshold to separate the neutrons and the photons. The discrimination will rather be achieved by time of flight methods which is discussed under the second chapter in this thesis; Experimental results. An other experiment was done in order to investigate whether it is possible to detect any delayed components from the spontaneous fission of Cf. The result showed that delayed components existed. Either they are delayed neutrons from exited fission products, or it is some delay related to the charge collection in the Cf detector. Correlation measurements showed that few events are coincident. Only 50% of the signals from the plastic scintillator are correlated with the Cf source

  2. Multielemental nondestructive neutron activation analysis of Dy, Mn, Eu, Na, Ga, W, La and Sm involving cyclic irradiations with 252Cf

    International Nuclear Information System (INIS)

    Narkhede, S.S.; Turel, Z.R.

    1995-01-01

    Dy, Mn, Eu, Na, Ga, W, La and Sm respond very well to INAA technique because of their favourable nuclear properties such as high thermal neutron cross-section or abundance. In the present work a method has been developed for the determination of these elements employing cycle irradiation with 252 Cf thermal neutron source. Radioassaying of the irradiated sample and standard was done employing HPGe detector in conjunction with a PC based MCA units. (author). 2 tabs

  3. Thermal neutron imaging with rare-earth-ion-doped LiCaAlF{sub 6} scintillators and a sealed {sup 252}Cf source

    Energy Technology Data Exchange (ETDEWEB)

    Kawaguchi, Noriaki, E-mail: famicom@mail.tagen.tohoku.ac.jp [Tokuyama Corporation, Shibuya 3-chome, Shibuya-ku, Tokyo 150-8383 (Japan); IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Yanagida, Takayuki; Fujimoto, Yutaka; Yokota, Yuui; Kamada, Kei [IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Fukuda, Kentaro; Suyama, Toshihisa [Tokuyama Corporation, Shibuya 3-chome, Shibuya-ku, Tokyo 150-8383 (Japan); Watanabe, Kenichi; Yamazaki, Atsushi [Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Chani, Valery [IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Yoshikawa, Akira [IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); New Industry Creation Hatchery Center, Tohoku University, Sendai 980-8579 (Japan)

    2011-10-01

    Thermal neutron imaging with Ce-doped LiCaAlF{sub 6} crystals has been performed. The prototype of the neutron imager using a Ce-doped LiCaAlF{sub 6} scintillating crystal and a position sensitive photomultiplier tube (PSPMT) which had 64 multi-channel anode was developed. The Ce-doped LiCaAlF{sub 6} single crystal was grown by the Czochralski method. A plate with dimensions of a diameter of 50x2 mm{sup 2} was cut from the grown crystal, polished, and optically coupled to PSPMT by silicone grease. The {sup 252}Cf source (<1 MBq) was sealed with 43 mm of polyethylene for neutron thermalization. Alphabet-shaped Cd pieces with a thickness of 2 mm were used as a mask for the thermal neutrons. After corrections for the pedestals and gain of each pixel, we successfully obtained two-dimensional neutron images using Ce-doped LiCaAlF{sub 6}.

  4. Undergraduate experiments using the neutron radiation from californium-252

    International Nuclear Information System (INIS)

    Rossel, J.; Golecki, I.

    1976-01-01

    Three experiments designed to demonstrate and measure several properties of the neutron radiation emitted by a 3μg 252 Cf source are described. The experiments constitute a special project carried out by a third-year undergraduate student at the Institute of Physics of the University of Neuchatel. The 252 Cf source is enclosed in a shield which allows a pencil of fast neutrons to pass through a central tube, while reducing the ambient radiation below the tolerance level. The shield consists of layers of borated paraffin wax, iron and cadmium. The first experiment uses an air-alcohol diffusion cloud chamber for the demonstration of tracks of recoil protons produced by the neutrons. Semi-quantitative measurements of track lengths give the correct order of magnitude of the proton energies. In the second experiment a liquid scintillator detector is used to scan the beam profile across the radiation shield enclosing the source. A pulse-shape-discrimination system discriminates between neutrons and gamma photons. The third experiment makes use of the nuclear emulsion technique to study the neutron energy distribution of 252 Cf. Preliminary results are compared with published values. (author)

  5. Angular momenta of fission fragments in the {alpha}-accompanied fission of {sup 252}Cf

    Energy Technology Data Exchange (ETDEWEB)

    Jandel, M.; Kliman, J.; Krupa, L.; Morhac, M. [Slovak Academy of Sciences, Department of Nuclear Physics, Bratislava (Slovakia); Joint Institute for Nuclear Research, Flerov Laboratory for Nuclear Reactions, Dubna (Russian Federation); Hamilton, J.H.; Kormicki, J.; Ramayya, A.V.; Hwang, J.K.; Luo, Y.X.; Fong, D.; Gore, P. [Vanderbilt University, Department of Physics, Nashville, TN (United States); Ter-Akopian, G.M.; Oganessian, Yu.Ts.; Rodin, A.M.; Fomichev, A.S.; Popeko, G.S. [Joint Institute for Nuclear Research, Flerov Laboratory for Nuclear Reactions, Dubna (Russian Federation); Daniel, A.V. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Rasmussen, J.O.; Macchiavelli, A.O.; Stoyer, M.A. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Donangelo, R.; Cole, J.D.

    2005-06-01

    For the first time, average angular momenta of the ternary fission fragments {sup 100,102}Zr, {sup 106}Mo, {sup 144,146}Ba and {sup 138,140,142}Xe from the {alpha}-accompanied fission of {sup 252}Cf were obtained from relative intensities of prompt {gamma}-ray transitions with the use of the statistical model calculation. Average values of the angular momenta were compared with the corresponding values for the same fission fragments from the binary fission of {sup 252}Cf. Results indicate the presence of a decreasing trend in the average values of angular momenta induced in ternary fission fragments compared to the same binary fission fragments. On the average, the total angular momentum extracted for ternary fission fragments is {proportional_to}1.4{Dirac_h} lower than in binary fission. Consequently, results indicate that the mechanism of the ternary {alpha}-particles emission may directly effect an induction of angular momenta of fission fragments, and possible scenarios of such mechanisms are discussed. Further, the dependence of the angular momenta of {sup 106}Mo and {sup 140}Xe on the number of emitted neutrons from correlated pairs of primary fragments was obtained also showing a decreasing dependence of average angular momenta with increasing number of emitted neutrons. Consequences are briefly discussed. (orig.)

  6. The temperature of fission fragments from spontaneous fission of 252Cf measured by time-of-flight spectrometer

    International Nuclear Information System (INIS)

    Popkiewicz, M.; Osuch, S.; Szeflinski, Z.; Sztampke, A.; Wilhelmi, Z.; Wolinska, M.; Zaganczyk, R.

    1997-01-01

    The detection system MONA (Modular Neutron Array) consisting of eight large BC-501A liquid scintillators, was applied to determine the temperature of fission fragments emitted in spontaneous fission of 252 Cf. The determination of the temperature was based on the measurement of the neutron spectra

  7. Calculated and measured brachytherapy dosimetry parameters in water for the Xoft Axxent X-Ray Source: an electronic brachytherapy source.

    Science.gov (United States)

    Rivard, Mark J; Davis, Stephen D; DeWerd, Larry A; Rusch, Thomas W; Axelrod, Steve

    2006-11-01

    A new x-ray source, the model S700 Axxent X-Ray Source (Source), has been developed by Xoft Inc. for electronic brachytherapy. Unlike brachytherapy sources containing radionuclides, this Source may be turned on and off at will and may be operated at variable currents and voltages to change the dose rate and penetration properties. The in-water dosimetry parameters for this electronic brachytherapy source have been determined from measurements and calculations at 40, 45, and 50 kV settings. Monte Carlo simulations of radiation transport utilized the MCNP5 code and the EPDL97-based mcplib04 cross-section library. Inter-tube consistency was assessed for 20 different Sources, measured with a PTW 34013 ionization chamber. As the Source is intended to be used for a maximum of ten treatment fractions, tube stability was also assessed. Photon spectra were measured using a high-purity germanium (HPGe) detector, and calculated using MCNP. Parameters used in the two-dimensional (2D) brachytherapy dosimetry formalism were determined. While the Source was characterized as a point due to the small anode size, S700 Source exhibited depth dose behavior similar to low-energy photon-emitting low dose rate sources 125I and l03Pd, yet with capability for variable and much higher dose rates and subsequently adjustable penetration capabilities. This paper presents the calculated and measured in-water brachytherapy dosimetry parameters for the model S700 Source at the aforementioned three operating voltages.

  8. Determination of 114Pd cumulative yield and investigation of the fine-structure at light peak in mass distribution of 252Cf spontaneous fission

    International Nuclear Information System (INIS)

    Yu Runlan; Li Xueliang; Cui Anzhi; Guo Jingru; Yan Shuhen; Tang Peijia; Liu Daming

    1991-07-01

    A rapid radiochemical procedure for Pd separation was developed. It was the first time to use radiochemical techniques to determine 114 Pd cumulative yield (2.50 ± 0.14)% in 252 Cf spontaneous fission. The cumulative yields of (3.50 ± 0.13)% and (3.70 ± 0.11)% for 112 Pd and 113g Ag were also obtained. These are in agreement with Skovorodkin's results. The cumulative yields determined show that there is a fine-structure at light peak of mass number A = 113 in the mass distribution of 252 Cf spontaneous fission

  9. Matrix effects correction on 252Cf shufflers by application of the alternating conditional expectation to neutron flux monitor data

    International Nuclear Information System (INIS)

    Pickrell, M.M.

    1992-01-01

    The 252 Cf shuffler assays fissile uranium and plutonium using active neutron interrogation and then counting the induced delayed neutrons. Using the shuffler, we conducted over 1700 assays of 55-gal. drums with 28 different matrices and several different fissionable materials. We measured the drums to diagnose the matrix and position effects on 252 Cf shuffler assays. The matrices incorporated metals, neutron poisons, and hydrogen in densities ranging from 0≤ pH ≤ 0.086 g/cm 3 , a range of cases more extreme than typically found in routine plant use. We used several neutron flux monitors during irradiation and kept statistics on the count rates of individual detector banks. The intent of these measurements was to gauge the effect of the matrix independently from the uranium assay

  10. 10 CFR 35.2406 - Records of brachytherapy source accountability.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of brachytherapy source accountability. 35.2406... Records of brachytherapy source accountability. (a) A licensee shall maintain a record of brachytherapy source accountability required by § 35.406 for 3 years. (b) For temporary implants, the record must...

  11. Average cross sections for the 252Cf neutron spectrum

    International Nuclear Information System (INIS)

    Dezso, Z.; Csikai, J.

    1977-01-01

    A number of average cross sections have been measured for 252 Cf neutrons in (n, γ), (n,p), (n,2n), (n,α) reactions by the activation method and for fission by fission chamber. Cross sections have been determined for 19 elements and 45 reactions. The (n,γ) cross section values lie in the interval from 0.3 to 200 mb. The data as a function of target neutron number increases up to about N=60 with minimum near to dosed shells. The values lie between 0.3 mb and 113 mb. These cross sections decrease significantly with increasing the threshold energy. The values are below 20 mb. The data do not exceed 10 mb. Average (n,p) cross sections as a function of the threshold energy and average fission cross sections as a function of Zsup(4/3)/A are shown. The results obtained are summarized in tables

  12. Proposed Californium-252 User Facility for Neutron Science at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Martin, R.C.; Laxson, R.R.; Knauer, J.B.

    1996-01-01

    The Radiochemical Engineering Development Center (REDC) at ORNL has petitioned to establish a Californium-252 User Facility for Neutron Science for academic, industrial, and governmental researchers. The REDC Californium Facility (CF) stores the national inventory of sealed 252 Cf neutron source for university and research loans. Within the CF, the 252 Cf storage pool and two uncontaminated hot cells currently in service for the Californium Program will form the physical basis for the User Facility. Relevant applications include dosimetry and experiments for neutron tumor therapy; fast and thermal neutron activation analysis of materials; experimental configurations for prompt gamma neutron activation analysis; neutron shielding and material damage studies; and hardness testing of radiation detectors, cameras, and electronics. A formal User Facility simplifies working arrangements and agreements between US DOE facilities, academia, and commercial interests

  13. Radioactive sources in brachytherapy:

    OpenAIRE

    Burger, Janez

    2003-01-01

    Background. In modern brachytherapy, a greast step forward was made in the 1960s in France with the introduction of new radioactive isotopes and new techniques. These innovations spread rapidly across Europe, though no single dosimetry standard had been set by then. In the new millennium, the advances in brachytherapy are further stimulated by the introduction of 3-D imaging techniques and the latest after loading irradiation equipment that use point sources. The international organiyation IC...

  14. In-water calibration of PDR 192Ir brachytherapy sources with an NE2571 ionization chamber

    International Nuclear Information System (INIS)

    Reynaert, N.; Verhaegen, F.; Thierens, H.

    1998-01-01

    An ionometric calibration procedure for 192 Ir PDR brachytherapy sources in terms of dose rate to water is presented. The calibration of the source is performed directly in a water phantom at short distances (1.0, 2.5 and 5.0 cm) using an NE2571 Farmer type ion chamber. To convert the measured air-kerma rate in water to dose rate to water a conversion factor (CF) was calculated by adapting the medium-energy x-ray dosimetry protocol for a point source geometry (diverging beam). The obtained CF was verified using two different methods. Firstly, the CF was calculated by Monte Carlo simulations, where the source-ionization chamber geometry was modelled accurately. In a second method, a combination of Monte Carlo simulations and measurements of the air-kerma rate in water (at 1.0, 2.5 and 5.0 cm distance) and in air (1 m distance) was used to determine the CF. The obtained CFs were also compared with conversion factors calculated with the adapted dosimetry protocol for high-energy photons introduced by Toelli. All calculations were done for a Gammamed PDR 192 Ir source-NE2571 chamber geometry. The conversion factors obtained with the four different methods agree to within 1% at the three distances of interest. We obtained the following values (medium-energy x-ray protocol): CF(1 cm) = 1.458; CF(2.5 cm) = 1.162; CF(5.0 cm) = 1.112 (1σ=0.7% for the three distances of interest). The obtained results were checked with TLD measurements. The values of the specific dose rate constant and the radial dose function calculated in this work are in accordance with the literature data. (author)

  15. HeLa cell tumor response to 60Co, Cs-137, Cf-252 radiations and cisplatin chemotherapy in nude mice

    International Nuclear Information System (INIS)

    Maruyama, Y.; Feola, J.M.; Beach, J.L.

    1984-01-01

    HeLa cells were implanted into athymic nude mice from tissue culture and solid tumors established (HeLa cell tumor or HCT). Large cell numbers of 1 X 10 7 were required to obtain consistent and progressive growth, and tumor growth followed a Gompertzian mode. Irradiation studies were carried out using acute Cobalt-60 (60Co), low-dose-rate (LDR) Cs-137 and LDR Cf-252. Cf-252, a neutron-emitting radioisotope, produced an immediate tumor shrinkage and regression response after a dose of 279 cGy. Acute 60Co or LDR Cs-137 irradiation with 1000 cGy had little effect on the HCT. After a dose of 2000 cGy of 60Co radiation tumor shrinkage followed a latent period of approximately 5 days. Cisplatin had no effect on the HCT in nude mice in stationary or late exponential growth

  16. Calculated and measured brachytherapy dosimetry parameters in water for the Xoft Axxent X-Ray Source: An electronic brachytherapy source

    International Nuclear Information System (INIS)

    Rivard, Mark J.; Davis, Stephen D.; DeWerd, Larry A.; Rusch, Thomas W.; Axelrod, Steve

    2006-01-01

    A new x-ray source, the model S700 Axxent trade mark sign X-Ray Source (Source), has been developed by Xoft Inc. for electronic brachytherapy. Unlike brachytherapy sources containing radionuclides, this Source may be turned on and off at will and may be operated at variable currents and voltages to change the dose rate and penetration properties. The in-water dosimetry parameters for this electronic brachytherapy source have been determined from measurements and calculations at 40, 45, and 50 kV settings. Monte Carlo simulations of radiation transport utilized the MCNP5 code and the EPDL97-based mcplib04 cross-section library. Inter-tube consistency was assessed for 20 different Sources, measured with a PTW 34013 ionization chamber. As the Source is intended to be used for a maximum of ten treatment fractions, tube stability was also assessed. Photon spectra were measured using a high-purity germanium (HPGe) detector, and calculated using MCNP. Parameters used in the two-dimensional (2D) brachytherapy dosimetry formalism were determined. While the Source was characterized as a point due to the small anode size, P (5) were 0.20, 0.24, and 0.29 for the 40, 45, and 50 kV voltage settings, respectively. For 1 125 I and 103 Pd, yet with capability for variable and much higher dose rates and subsequently adjustable penetration capabilities. This paper presents the calculated and measured in-water brachytherapy dosimetry parameters for the model S700 Source at the aforementioned three operating voltages

  17. Long-term effects of an intracavitary treatment with californium-252 on normal tissue

    International Nuclear Information System (INIS)

    Sullivan, M.F.; Beamer, J.L.; Mahony, T.D.; Cross, F.T.; Lund, J.E.; Endres, G.W.R.

    1976-01-01

    About one hundred fifty swine were exposed to either radium-226 or californium-252 sources in the uterine cervix to determine an RBE for both acute and long-term effects. That value for early changes in the tissues at risk in the treatment of cervical cancer was between 6.2 and 6.8. The incidence of complications increased with time after exposure, especially among animals treated with 252 Cf. Analysis of rectal injury showed that ulceration occurred frequently within a year postexposure at doses between 1600 and 2400 rad calculated at 2 cm lateral to the source midline. Fat necrosis and smooth muscle atrophy, resulting in a local rectal stricture, were delayed changes observed in some animals. The lower ureter was the site for a greater frequency of complications than the GI tract. Ureteral stricture often occurred at doses of 1200 rad from 252 Cf and 7000 rad from 226 Ra. Observation of delayed effects in the uterine-cervix in animals held up to 4 years postexposure indicate that the RBE for 252 Cf may be increased to a value as high as 18, while repair may have even decreased it to about 5.6 in the rectum. Fifty swine are still being observed for long-term effects after doses above 800 rad from 252 Cf and 5000 rad from 226 Ra

  18. Neutron source for a reactor

    International Nuclear Information System (INIS)

    Kobayashi, Hiromasa.

    1975-01-01

    Object: To easily increase a start-up power of a reactor without irradiation in other reactors. Structure: A neutron source comprises Cf 252 , a natural antimony rod, a layer of beryllium, and a vessel of neutron source. On upper and lower portion of Cf 252 are arranged natural antimony rods, which are surrounded by the Be layer, the entirety being charged into the vessel. The Cf 252 may emit neutron, has a half life more than a period of operating cycle of the reactor and is less deteriorated even irradiated by radioactive rays while being left within the reactor. The natural antimony rod is radioactivated by neutron from Cf 252 and neutron as reactor power increases to emit γ rays. The Be absorbs γ rays to emit the neutron. The antimony rod is irradiated within the reactor. Further, since the Cf 252 is small in neutron absorption cross section, it is hard to be deteriorated even while being inserted within the reactor. (Kamimura, M.)

  19. Detection alpha particles and Cf-252 fission fragments with track solid detectors and with surface barrier detectors: efficiency determination

    International Nuclear Information System (INIS)

    Khouri, M.T.F.C.; Koskinas, M.F.; Andrade, C. de; Vilela, E.C.; Hinostroza, H.; Kaschiny, J.R.A.; Costa, M.S. da; Rizzo, P.; Santos, W.M.S.

    1990-01-01

    The technique of particle detection by solid track detectors, types of developing and analysis of results are presented. Efficiency measurements of alpha particle detection with Makrofol e and surface barrier detector are made. Detection of Cf-252 fission fragments is shown. (L.C.)

  20. Neutron-neutron angular correlations in spontaneous fission of 252Cf and 240Pu

    Science.gov (United States)

    Verbeke, J. M.; Nakae, L. F.; Vogt, R.

    2018-04-01

    Background: Angular anisotropy has been observed between prompt neutrons emitted during the fission process. Such an anisotropy arises because the emitted neutrons are boosted along the direction of the parent fragment. Purpose: To measure the neutron-neutron angular correlations from the spontaneous fission of 252Cf and 240Pu oxide samples using a liquid scintillator array capable of pulse-shape discrimination. To compare these correlations to simulations combining the Monte Carlo radiation transport code MCNPX with the fission event generator FREYA. Method: Two different analysis methods were used to study the neutron-neutron correlations with varying energy thresholds. The first is based on setting a light output threshold while the second imposes a time-of-flight cutoff. The second method has the advantage of being truly detector independent. Results: The neutron-neutron correlation modeled by FREYA depends strongly on the sharing of the excitation energy between the two fragments. The measured asymmetry enabled us to adjust the FREYA parameter x in 240Pu, which controls the energy partition between the fragments and is so far inaccessible in other measurements. The 240Pu data in this analysis was the first available to quantify the energy partition for this isotope. The agreement between data and simulation is overall very good for 252Cf(sf ) and 240Pu(sf ) . Conclusions: The asymmetry in the measured neutron-neutron angular distributions can be predicted by FREYA. The shape of the correlation function depends on how the excitation energy is partitioned between the two fission fragments. Experimental data suggest that the lighter fragment is disproportionately excited.

  1. The temperature of fission fragments from spontaneous fission of {sup 252}Cf measured by time-of-flight spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Popkiewicz, M.; Osuch, S.; Szeflinski, Z.; Sztampke, A.; Wilhelmi, Z.; Wolinska, M.; Zaganczyk, R. [Warsaw Univ., Inst. of Experimental Physics, Nuclear Physics Div., Warsaw (Poland)

    1997-12-31

    The detection system MONA (Modular Neutron Array) consisting of eight large BC-501A liquid scintillators, was applied to determine the temperature of fission fragments emitted in spontaneous fission of {sup 252}Cf. The determination of the temperature was based on the measurement of the neutron spectra. 5 refs, 2 figs.

  2. Prompt neutron fission spectrum mean energies for the fissile nuclides and 252Cf

    International Nuclear Information System (INIS)

    Holden, N.E.

    1985-01-01

    The international standard for a neutron spectrum is that produced from the spontaneous fission of 252 Cf, while the thermal neutron induced fission neutron spectra for the four fissile nuclides, 233 U, 235 U, 239 Pu, and 241 Pu are of interest from the standpoint of nuclear reactors. The average neutron energies of these spectra are tabulated. The individual measurements are recorded with the neutron energy range measured, the method of detection as well as the average neutron energy for each author. Also tabulated are the measurements of the ratio of mean energies for pairs of fission neutron spectra. 75 refs., 9 tabs

  3. Standard test method for nondestructive assay of nuclear material in scrap and waste by passive-Active neutron counting using 252Cf shuffler

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers the nondestructive assay of scrap and waste items for U, Pu, or both, using a 252Cf shuffler. Shuffler measurements have been applied to a variety of matrix materials in containers of up to several 100 L. Corrections are made for the effects of matrix material. Applications of this test method include measurements for safeguards, accountability, TRU, and U waste segregation, disposal, and process control purposes (1, 2, 3). 1.1.1 This test method uses passive neutron coincidence counting (4) to measure the 240Pu-effective mass. It has been used to assay items with total Pu contents between 0.03 g and 1000 g. It could be used to measure other spontaneously fissioning isotopes such as Cm and Cf. It specifically describes the approach used with shift register electronics; however, it can be adapted to other electronics. 1.1.2 This test method uses neutron irradiation with a moveable Cf source and counting of the delayed neutrons from the induced fissions to measure the 235U equiva...

  4. Estimation of the LET threshold of single event upset of microelectronics in experiments with Cf-252

    International Nuclear Information System (INIS)

    Kuznetsov, N.V.; Nymmik, R.A.

    1996-01-01

    A method is proposed for analyzing single event upsets (SEU) in large scale integration circuits of random access memory (RAM) when exposed to Cf-252 fission fragments. The method makes is possible to find the RAM linear energy transfer (LET) threshold to be used for estimations of RAM SEU rates in space. The method is illustrated by analyzing experimental data for the 2 x 8 kbit CMOS/bulk RAM. (author)

  5. Detection of alpha particles and Cf-252 fission fragments with solid track detectors and surface barrier detector. Efficiency calculation

    International Nuclear Information System (INIS)

    Khouri, M.T.F.C.; Koskinas, M.F.; Andrade, C. de; Vilela, E.C.; Hinostroza, H.; Kaschiny, J.E.A.; Costa, M.S. da; Rizzo, P.; Santos, W.M.S.

    1990-01-01

    A technique for particle detection by using track solid detector and also types of revealing and result analysis are presented concerned to Cf-252 fission fragments detection. Measurements of alpha particles detection efficiency using Makrofol E and surface barrier detector are performed. (L.C.J.A.)

  6. Parameters for several plutonium nuclides and 252Cf of safeguards interest

    International Nuclear Information System (INIS)

    Zucker, M.S.; Holden, N.E.

    1984-01-01

    Sets of the neutron emission multiplicity distribution gleaned from the literature for plutonium nuclides and 252 Cf are considered. A methodology for rendering the different sets comparable is presented and used to convert the sets to a common basis such that the differences can be evaluated objectively and that allows realistic estimate of the uncertainties. This in turn permits development of a canonical consensus set in certain instances. Evaluated data on the average neutron multiplicity, the total half-lives, and the half-lives for spontaneous fission are also given. A careful search of the literature reveals that the data on neutron multiplicity distributions for many nuclides is surprisingly sparse, considering that almost thirty years has elapsed since the original pioneering work, which in some cases, yield the only reported value. 93 references, 26 tables

  7. 1987 Neutron and gamma personnel dosimeter intercomparison study using a D2O-moderated 252Cf source

    International Nuclear Information System (INIS)

    Swaja, R.E.; West, L.E.; Sims, C.S.; Welty, T.J.

    1989-05-01

    The thirteenth Personnel Dosimetry Intercomparison Study (i.e., PDIS 13) was conducted during April 1987 as a joint effort by Oak Ridge National Laboratory's (ORNL) Dosimetry Applications Research Group and the Southwest Radiation Calibration Center at the University of Arkansas. A total of 48 organizations (34 from the US and 14 from abroad) participated in PDIS 13. Participants submitted a total of 1,113 neutron and gamma dosimeters for this mixed field study. The dosimeters were transferred by mail and were handled by experimental personnel at ORNL and the University of Arkansas. The type of neutron dosimeter and the percentage of participants submitting that type are as follows: TLD-albedo (49%), direct interaction TLD (31%), CR-39 (17%), film (3%). The type of gamma dosimeter and the percentage of participants submitting that type are as follows: Li 2 B 4 O 7 , alone or in combination with CaSO 4 , (69%), 7 LiF (28%), natural LiF (3%). Radiation exposures in PDIS 13 were limited to 0.5 and 1.5 mSv from 252 Cf moderated by 15-cm of D 2 O. Traditional exposures using the Health Physics Research Reactor (HPRR) were not possible due to the fact that all reactors at ORNL, including the HPRR, were shutdown by order of the Department of Energy at the time the intercomparison was performed. Planned exposures using a 238 PuBe source were negated by a faulty timing mechanism. Based on accuracy and precision, direct interaction TLD dosimeters exhibited the best performance in PDIS 13 neutron measurements. They were followed, in order of best performance, by CR-39, TLD albedo, and film. The Li 2 B 4 O 7 type TLD dosimeters exhibited the best performance in PDIS 13 gamma measurements. They were followed by natural LiF, 7 LiF, and film. 12 refs., 1 fig., 5 tabs

  8. Comparison of 252Cf time correlated induced fission with AmLi induced fission on fresh MTR reserach reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Jay Prakash [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-01

    The objectives of this project are to calibrate the Advanced Experimental Fuel Counter (AEFC), benchmark MCNP simulations using experimental results, investigate the effects of change in fuel assembly geometry, and finally to show the boost in doubles count rates with 252Cf active soruces due to the time correlated induced fission (TCIF) effect.

  9. Importance of the elemental composition in brachytherapy with neutrons; Importancia de la composicion elemental en braquiterapia con neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.; Balcazar G, M. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Azorin N, J. [UAM-I, 09340 Mexico D.F. (Mexico); Francois L, J.L. [ICN-UNAM, 04510 Mexico D.F. (Mexico)

    2004-07-01

    An analysis is presented of as the small differences that exist in the elementary composition of the wicked tumors, healthy fabrics and some material substitutes of fabric employees in dosimetry, they generate variations in the value of the kerma coefficient and consequently in the absorbed dose of neutrons in the interval 11 eV to 29 MeV. These differences make that the coefficient of kerma of neutrons average for the considered wicked tumors, be between 6% and 7% smaller that the coefficient of kerma of neutrons average for soft fabric, in the interval of interest in therapy with quick neutrons. These results have a special importance during the process of planning of brachytherapy treatments with sources of {sup 252} Cf, to optimize and to individualize the treatments to the patients. (Author)

  10. Definitive Brachytherapy for Kaposi's Sarcoma

    International Nuclear Information System (INIS)

    Williams, A.; Ezzell, G.; Zalupski, M.; Fontanesi, J.

    1996-01-01

    Purpose: To assess the efficacy and possible complications in patients diagnosed with Kaposi's sarcoma and treated with definitive brachytherapy. Methods and Materials: Between January, 1995 and December, 1995, four patients with Kaposi's sarcoma (KS) were treated with brachytherapy. Three patients, all with positive HIV status were treated using Iridium 192 (Ir-192) sources via a high-dose rate remote afterloader. One patient with endemic KS was treated using the application of catheters loaded with Californium 252. Eight sites were treated and included scalp, feet, nose, penis, hand, neck, and back. Dose rate for Ir-192 was 330cGy/fx to a total dose of 990cGy. The Californium was delivered as 100nGy/b.i.d. to a total dose of 900nGy. Follow-up as ranged from 2-6 months. Results: All four patients remain alive. Seven of eight sites have had complete clinical response and each patient has reported durable pain relief that has not subsided through last follow-up of 1/96. Two of eight sites, both treated with surface mold technique with Californium 252 developed moist desquamation. The remaining six sites did not demonstrate significant toxicity. Conclusion: Brachytherapy can offer Kaposi's sarcoma patients results that are equivalent to external beam radiation therapy, with minimal complications, a shorter treatment time and potential cost effectiveness

  11. Spectroscopy of neutron-rich nuclei populated in the spontaneous fission of 252Cf and 248Cm

    International Nuclear Information System (INIS)

    Smith, A. G.; Simpson, G. S.; Billowes, J.; Durell, J. L.; Phillips, W. R.; Dagnall, P. J.; Freeman, S. J.; Leddy, M.; Roach, A. A.; Smith, J. F.

    1999-01-01

    In this paper we present research that has been carried out using the Euroball and Eurogam arrays to detect γ rays emitted from spontaneously fissioning 248 Cm and 252 Cf. The paper focuses on three sub-areas of current activity, namely, the measurement of yields of secondary fragment pairs, the measurement of state lifetimes at around spin 10, and recent measurements of g-factors of excited states in fission fragments. (c) 1999 American Institute of Physics

  12. Long-term effects of an intracavitary treatment with californium-252 on normal tissue. [Swine, /sup 226/Ra

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, M.F.; Beamer, J.L.; Mahony, T.D.; Cross, F.T.; Lund, J.E.; Endres, G.W.R.

    1976-01-01

    About one hundred fifty swine were exposed to either radium-226 or californium-252 sources in the uterine cervix to determine an RBE for both acute and long-term effects. That value for early changes in the tissues at risk in the treatment of cervical cancer was between 6.2 and 6.8. The incidence of complications increased with time after exposure, especially among animals treated with /sup 252/Cf. Analysis of rectal injury showed that ulceration occurred frequently within a year postexposure at doses between 1600 and 2400 rad calculated at 2 cm lateral to the source midline. Fat necrosis and smooth muscle atrophy, resulting in a local rectal stricture, were delayed changes observed in some animals. The lower ureter was the site for a greater frequency of complications than the GI tract. Ureteral stricture often occurred at doses of 1200 rad from /sup 252/Cf and 7000 rad from /sup 226/Ra. Observation of delayed effects in the uterine-cervix in animals held up to 4 years postexposure indicate that the RBE for /sup 252/Cf may be increased to a value as high as 18, while repair may have even decreased it to about 5.6 in the rectum. Fifty swine are still being observed for long-term effects after doses above 800 rad from /sup 252/Cf and 5000 rad from /sup 226/Ra.

  13. New isomeric states in 152,154,156Nd produced by spontaneous fission of 252Cf

    International Nuclear Information System (INIS)

    Gautherin, C.; Houry, M.; Korten, W.; Le Coz, Y.; Lucas, R.; Phan, X.H.; Theisen, C.; Belier, G.; Girod, M.; Meot, V.; Peru, S.; Astier, A.; Ducroux, L.; Meyer, M.; Redon, N.

    1998-01-01

    Isomeric states have been observed in fission-fragments produced by spontaneous fission of 252 Cf. These states are found in neutron rich nuclei of different structure and deformations. About 50 isomeric nuclei have been observed using coincidences between γ-rays identified in EUROGAM II and fission fragments detected in photovoltaic cells (SAPhIR). Lifetimes in the range from 20 ns to 2μs have been measured. Presented calculations based on HFB+D1S force on new measured isomeric states in the 152,154,156 Nd show evidence for K-isomers. (orig.)

  14. Microarray analysis of DNA damage repair gene expression profiles in cervical cancer cells radioresistant to 252Cf neutron and X-rays

    International Nuclear Information System (INIS)

    Qing, Yi; Wang, Ge; Wang, Dong; Yang, Xue-Qin; Zhong, Zhao-Yang; Lei, Xin; Xie, Jia-Yin; Li, Meng-Xia; Xiang, De-Bing; Li, Zeng-Peng; Yang, Zhen-Zhou

    2010-01-01

    The aim of the study was to obtain stable radioresistant sub-lines from the human cervical cancer cell line HeLa by prolonged exposure to 252 Cf neutron and X-rays. Radioresistance mechanisms were investigated in the resulting cells using microarray analysis of DNA damage repair genes. HeLa cells were treated with fractionated 252 Cf neutron and X-rays, with a cumulative dose of 75 Gy each, over 8 months, yielding the sub-lines HeLaNR and HeLaXR. Radioresistant characteristics were detected by clone formation assay, ultrastructural observations, cell doubling time, cell cycle distribution, and apoptosis assay. Gene expression patterns of the radioresistant sub-lines were studied through microarray analysis and verified by Western blotting and real-time PCR. The radioresistant sub-lines HeLaNR and HeLaXR were more radioresisitant to 252 Cf neutron and X-rays than parental HeLa cells by detecting their radioresistant characteristics, respectively. Compared to HeLa cells, the expression of 24 genes was significantly altered by at least 2-fold in HeLaNR cells. Of these, 19 genes were up-regulated and 5 down-regulated. In HeLaXR cells, 41 genes were significantly altered by at least 2-fold; 38 genes were up-regulated and 3 down-regulated. Chronic exposure of cells to ionizing radiation induces adaptive responses that enhance tolerance of ionizing radiation and allow investigations of cellular radioresistance mechanisms. The insights gained into the molecular mechanisms activated by these 'radioresistance' genes will lead to new therapeutic targets for cervical cancer

  15. Teratogenic effect of Californium-252 irradiation in rats

    International Nuclear Information System (INIS)

    Satow, Yukio; Lee, Juing-Yi; Hori, Hiroshi; Okuda, Hiroe; Tsuchimoto, Shigeo; Sawada, Shozo; Yokoro, Kenjiro

    1989-01-01

    The teratogenicity of Californium-252 (Cf-252) irradiation which generates approximately 70% 2.3 MeV fast neutron and 30% gamma rays was evaluated. A single whole body exposure of Cf-252 at various doses was given to pregnant rats on day 8 or 9 of pregnancy, followed by microscopic autopsy of the fetuses at the terminal stage of pregnancy to search for external and internal malformations. For comparison, pregnant rats were irradiated with various doses of Cobalt-60 (Co-60) standard gamma rays at the same dose rate (1 rad/min.). The doses were 20-120 rad of Cf-252 and 80-220 rad of Co-60. Using frequency of radiation induced malformations observed on day 8 of pregnancy as an index, relative biological effectiveness (RBE) of 2.3-2.7 was obtained from the straight line obtained by modifying by the least squares method the frequency curves of malformed fetuses in total implants and in surviving fetuses. The types of malformations induced by Cf-252 and Co-60 irradiation were alike. Using fetal LD 50 as an index, 2.4 was obtained as RBE when irradiated on day 8 of pregnancy and 3.1 as that when irradiated on day 9. The results showed that Cf-252 had stronger a teratogenic effect than Co-60 gamma rays. (author)

  16. Survey of potential markets for devices using Californium-252

    International Nuclear Information System (INIS)

    Permar, P.H.

    1975-01-01

    Potential applications for devices or systems containing 252 Cf in the years from 1975 to 1980 are estimated. The estimated number of devices and associated business value were derived from a survey of 46 industrial, educational and governmental organizations conducted from Jan. to May, 1975. Applications for devices and systems based on 252 Cf are expected to increase by a factor of 7 in the 6-y period from 1975 to 1980. The annual business value of 252 Cf devices should increase from 1.5 million dollars in 1975 to 10.8 million dollars in 1980. The potential European market should be several times as large as the US market, based on actual sales of 252 Cf, which have been two to four times greater in Europe than in the US

  17. Primary calibration of coiled 103Pd brachytherapy sources

    International Nuclear Information System (INIS)

    Paxton, Adam B.; Culberson, Wesley S.; DeWerd, Larry A.; Micka, John A.

    2008-01-01

    Coiled 103 Pd brachytherapy sources have been developed by RadioMed Corporation for use as low-dose-rate (LDR) interstitial implants. The coiled sources are provided in integer lengths from 1 to 6 cm and address many common issues seen with traditional LDR brachytherapy sources. The current standard for determining the air-kerma strength (S K ) of low-energy LDR brachytherapy sources is the National Institute of Standards and Technology's Wide-Angle Free-Air Chamber (NIST WAFAC). Due to geometric limitations, however, the NIST WAFAC is unable to determine the S K of sources longer than 1 cm. This project utilized the University of Wisconsin's Variable-Aperture Free-Air Chamber (UW VAFAC) to determine the S K of the longer coiled sources. The UW VAFAC has shown agreement in S K values of 1 cm length coils to within 1% of those determined with the NIST WAFAC, but the UW VAFAC does not share the same geometric limitations as the NIST WAFAC. A new source holder was constructed to hold the coiled sources in place during measurements with the UW VAFAC. Correction factors for the increased length of the sources have been determined and applied to the measurements. Using the new source holder and corrections, the S K of 3 and 6 cm coiled sources has been determined. Corrected UW VAFAC data and ionization current measurements from well chambers have been used to determine calibration coefficients for use in the measurement of 3 and 6 cm coiled sources in well chambers. Thus, the UW VAFAC has provided the first transferable, primary measurement of low-energy LDR brachytherapy sources with lengths greater than 1 cm

  18. Third-party brachytherapy source calibrations and physicist responsibilities: Report of the AAPM Low Energy Brachytherapy Source Calibration Working Group

    International Nuclear Information System (INIS)

    Butler, Wayne M.; Bice, William S. Jr.; DeWerd, Larry A.; Hevezi, James M.; Huq, M. Saiful; Ibbott, Geoffrey S.; Palta, Jatinder R.; Rivard, Mark J.; Seuntjens, Jan P.; Thomadsen, Bruce R.

    2008-01-01

    The AAPM Low Energy Brachytherapy Source Calibration Working Group was formed to investigate and recommend quality control and quality assurance procedures for brachytherapy sources prior to clinical use. Compiling and clarifying recommendations established by previous AAPM Task Groups 40, 56, and 64 were among the working group's charges, which also included the role of third-party handlers to perform loading and assay of sources. This document presents the findings of the working group on the responsibilities of the institutional medical physicist and a clarification of the existing AAPM recommendations in the assay of brachytherapy sources. Responsibility for the performance and attestation of source assays rests with the institutional medical physicist, who must use calibration equipment appropriate for each source type used at the institution. Such equipment and calibration procedures shall ensure secondary traceability to a national standard. For each multi-source implant, 10% of the sources or ten sources, whichever is greater, are to be assayed. Procedures for presterilized source packaging are outlined. The mean source strength of the assayed sources must agree with the manufacturer's stated strength to within 3%, or action must be taken to resolve the difference. Third party assays do not absolve the institutional physicist from the responsibility to perform the institutional measurement and attest to the strength of the implanted sources. The AAPM leaves it to the discretion of the institutional medical physicist whether the manufacturer's or institutional physicist's measured value should be used in performing dosimetry calculations

  19. The needs for brachytherapy source calibrations in the United States

    International Nuclear Information System (INIS)

    Coursey, B.M.; Goodman, L.J.; Hoppes, D.D.; Loevinger, R.; McLaughlin, W.L.; Soares, C.G.; Weaver, J.T.

    1992-01-01

    Brachytherapy sources of beta and gamma radiation ('brachy' is from the Greek, meaning 'near') have a long history of use in interstitial, intracavitary, intraluminal, and ocular radiation therapy. In the past the US national standards for these sources were often specified in activity or milligram radium equivalent. With the introduction of new radionuclide sources to replace radium, source strength calibrations are now expressed as air kerma rate at a meter. In this paper, we review the NIST standards for brachytherapy sources, list some of the common radionuclides and source encapsulations in use in the US radiology community, and describe the latest NIST work, in collaboration with several US medical institutions, on a method of two- and three-dimensional dose mapping of brachytherapy sources using radiochromic films. (orig.)

  20. A comparison study on various low energy sources in interstitial prostate brachytherapy.

    Science.gov (United States)

    Bakhshabadi, Mahdi; Ghorbani, Mahdi; Khosroabadi, Mohsen; Knaup, Courtney; Meigooni, Ali S

    2016-02-01

    Low energy sources are routinely used in prostate brachytherapy. (125)I is one of the most commonly used sources. Low energy (131)Cs source was introduced recently as a brachytherapy source. The aim of this study is to compare dose distributions of (125)I, (103)Pd, and (131)Cs sources in interstitial brachytherapy of prostate. ProstaSeed (125)I brachytherapy source was simulated using MCNPX Monte Carlo code. Additionally, two hypothetical sources of (103)Pd and (131)Cs were simulated with the same geometry as the ProstaSeed (125)I source, while having their specific emitted gamma spectra. These brachytherapy sources were simulated with distribution of forty-eight seeds in a phantom including prostate. The prostate was considered as a sphere with radius of 1.5 cm. Absolute and relative dose rates were obtained in various distances from the source along the transverse and longitudinal axes inside and outside the tumor. Furthermore, isodose curves were plotted around the sources. Analyzing the initial dose profiles for various sources indicated that with the same time duration and air kerma strength, (131)Cs delivers higher dose to tumor. However, relative dose rate inside the tumor is higher and outside the tumor is lower for the (103)Pd source. The higher initial absolute dose in cGy/(h.U) of (131)Cs brachytherapy source is an advantage of this source over the others. The higher relative dose inside the tumor and lower relative dose outside the tumor for the (103)Pd source are advantages of this later brachytherapy source. Based on the total dose the (125)I source has advantage over the others due to its longer half-life.

  1. In situ prompt gamma-ray measurement of river water salinity in northern Taiwan using HPGe-252Cf probe

    International Nuclear Information System (INIS)

    Jiunnhsing Chao; Chien Chung

    1991-01-01

    A portable HPGe- 252 Cf probe dedicated to in situ survey of river water salinity was placed on board a fishing boat to survey the Tamsui River in northern Taiwan. The variation of water salinity is surveyed by measuring the 6111 keV chlorine prompt photopeak along the river. Results indicate that the probe can be used as a salinometer for rapid, in situ measurement in polluted rivers or sea. (author)

  2. Use of neutron activation and X-ray fluorescence with radioactive sources (Cf-252 and Am-241) for the instrumental qualiquantitative simultaneous analysis of some elements in samples of mineral supplement for animals

    International Nuclear Information System (INIS)

    Simabuco, S.M.

    1984-01-01

    To study the possibility of using two non-destructive (neutron activation and X-ray fluorescence) analyses in simultaneous quali-quantitative evaluations of some elements in mineral supplement for animals, a Cf-252 neutron source (11.3 mCi; 21.1 μgrams) and a Am-241 low energy gamma-ray emitter source (59.5 KeV; 100 mCi) were employed. For these sources, shieldings and sample irradiation systems were built. For the neutron activation analysis a reservoir of 72 cm height and 43 cm diameter was filled with paraffine, and the samples and neutron sources were put inside this reservoir using polypropilene and nylon tubes. To detect the gamma-rays emitted by the radioisotopes a well-type solid NaI(Tl) crystal scintillator (3x3') was used, coupled to a multi-channel analyser. For the X-ray fluorescence analysis a lead cylinder of 9.75 cm height and 5.6 cm diameter (with 0.7 cm thickness) was made and internally lined with a 0.36 mm copper and 0.1 mm aluminium foil. (Author) [pt

  3. Radiography using californium-252 neutron sources

    International Nuclear Information System (INIS)

    Ray, J.W.

    1975-01-01

    The current status in the technology of neutron radiography using californium-252 neutron sources is summarized. Major emphasis is on thermal neutron radiography since it has the widest potential applicability at the present time. Attention is given to four major factors which affect the quality and useability of thermal neutron radiography: source neutron thermalization, neutron beam extraction geometry, neutron collimator dimensions, and neutron imaging methods. Each of these factors has a major effect on the quality of the radiographs which are obtained from a californium source neutron radiography system and the exposure times required to obtain the radiographs; radiograph quality and exposure time in turn affect the practicality of neutron radiography for specific nondestructive inspection applications. A brief discussion of fast neutron radiography using californium-252 neutron sources is also included. (U.S.)

  4. Quality assurance of Vari-source high dose rate (HDR) brachytherapy- remote after loader and cost effectiveness of Vari-source HDR- brachytherapy: NORI, Islamabad experience

    International Nuclear Information System (INIS)

    Ahmad, N.; Mahmood, H.; Jafri, S.R.A.

    2004-01-01

    A quality control of Vari-Source high dose rate (HDR) remote after loading brachytherapy machine was carried out and the cost effectiveness of HDR brachytherapy machine was also evaluated considering the cost of ten Iridium-192 wire sources at Nuclear Medicine, Oncology and Radiotherapy Institute (NORI), Islamabad, Pakistan. A total number of 253 intracavitary insertions were done in 98 patients from October 1996 to May 2001. The results of the quality control tests performed during 1996 to 2001 were within the acceptable limits. The cost effectiveness of Vari-Source HDR brachytherapy machine was also evaluated. The average cost per patient was calculated as US$ 491. Small number of patients was treated as the machine was used for gynecologic malignancies only. The objective was to assess the quality control status of HDR brachytherapy machine on patient treatment day, source exchange day and periodic day (monthly basis). It was found that the cost per patient can be minimized if other type of cancer patients are also treated on Vari-Source HDR machine. (author)

  5. A comparison study on various low energy sources in interstitial prostate brachytherapy

    Directory of Open Access Journals (Sweden)

    Mahdi Bakhshabadi

    2016-02-01

    Full Text Available Purpose: Low energy sources are routinely used in prostate brachytherapy. 125 I is one of the most commonly used sources. Low energy 131 Cs source was introduced recently as a brachytherapy source. The aim of this study is to compare dose distributions of 125 I, 103 Pd, and 131 Cs sources in interstitial brachytherapy of prostate. Material and methods: ProstaSeed 125 I brachytherapy source was simulated using MCNPX Monte Carlo code. Additionally, two hypothetical sources of 103 Pd and 131 Cs were simulated with the same geometry as the ProstaSeed 125 I source, while having their specific emitted gamma spectra. These brachytherapy sources were simulated with distribution of forty-eight seeds in a phantom including prostate. The prostate was considered as a sphere with radius of 1.5 cm. Absolute and relative dose rates were obtained in various distances from the source along the transverse and longitudinal axes inside and outside the tumor. Furthermore, isodose curves were plotted around the sources. Results : Analyzing the initial dose profiles for various sources indicated that with the same time duration and air kerma strength, 131 Cs delivers higher dose to tumor. However, relative dose rate inside the tumor is higher and outside the tumor is lower for the 103 Pd source. Conclusions : The higher initial absolute dose in cGy/(h.U of 131 Cs brachytherapy source is an advantage of this source over the others. The higher relative dose inside the tumor and lower relative dose outside the tumor for the 103 Pd source are advantages of this later brachytherapy source. Based on the total dose the 125 I source has advantage over the others due to its longer half-life.

  6. Influence of paternal 252Cf neutron exposure on abnormal sperm, embryonal lethality, and liver tumorigenesis in the F1 offspring of mice

    International Nuclear Information System (INIS)

    Watanabe, Hiromitsu; Takahashi, Tadateru; Lee, Juing-Yi

    1996-01-01

    Experiments were conducted to determine whether neutron-induced genetic damage in parental germline cells can lead to the development of cancer in the offspring. Seven-week-old C3H male mice were irradiated with 252 Cf neutrons at a dose of 0, 50, 100, or 200 cGy. Two weeks or 3 months after irradiation, the male mice were mated with virgin 9-week-old C57BL females. Two weeks after irradiation, the irradiated male mice showed an increased incidence of sperm abnormalities, which led to embryo lethalities in a dose-dependent manner when they were mated with unirradiated female mice. Furthermore, liver tumors in male offspring of male mice in the 50 cGy group were significantly increased in 19 of 44 (43.2%) animals, in clear contrast to the unirradiated group (1 of 31; 3.2%) (P 1 generation may be caused by genetic transmission of hepatoma-associated trait (s) induced by 252 Cf neutron irradiation. (author)

  7. Fabrication of californium-252 sources in the United Kingdom

    International Nuclear Information System (INIS)

    Ainsworth, A.; Brady, M.W.; Thornett, W.H.

    1975-01-01

    The advent of californium-252 in weighable quantities and at a reasonable price has caused some rethinking among neutron source suppliers. To explore this market the Radiochemical Center Ltd. has purchased 2 mg of californium-252, and subdivided this into a wide range of sources. To take advantage of its high specific neutron emission, a small double welded stainless steel capsule 7.8mm diameter x 10mm high was chosen for stock sources and this entailed the use of a microdispensing technique which had to be specially developed. The apparatus and procedure for subdividing milligram amounts of californium-252 are described. Some details of our experience in processing these one milligram shipments are given. 100 sources with activities from 200 microgram to 0.01 microgram have been produced. Losses have been small. Measurement of neutron spectra gamma spectra and dose rates from encapsulated sources has confirmed published data. Though it is early days, little industrial interest in californium-252 sources has been detected, most of the sources have so far been required for research into activation analysis and two examples of this are given. (U.S.)

  8. Gamma ray transitions in de-excitation of 252Cf spontaneous fission fragments

    International Nuclear Information System (INIS)

    Khan, N.A.; Rashid, K.; Ahmad, M.; Qureshi, I.E.; Alam, G.D.; Ali, A.; Bhatti, N.; Horsch, F.

    1983-11-01

    Gamma rays in the range from 60 keV to 730 keV have been observed following the spontaneous fission of 252 Cf, with high resolution Ge(Li) detector, full width at half maximum (FWHM) of 700 eV at 122 keV, in coincidence with the two fission fragments observed with surface barrier detectors. A total number of 18, 636, 549 events were recorded over a run period of about 150 hours stretching over three weeks. The events were sorted to generate gamma ray spectra belonging to 2 amu intervals gamma of the fragment masses and 6 MeV intervals of the total kinetic energy released. Some of the prominent gamma lines belonging to various masses of the fission fragments have been identified. For some gamma lines, the intensities have been evaluated as a function of the total kinetic energy of the fission fragments. (authors)

  9. Fragment angular momentum and descent dynamics in {sup 252}Cf spontaneous fission

    Energy Technology Data Exchange (ETDEWEB)

    Popeko, G.S.; Ter-Akopian, G.M.; Daniel, A.V.; Oganessian, Y.T.; Kliman, J. [JINR, Dubna, 141980 (Russia); Ter-Akopian, G.M.; Hamilton, J.H.; Kormicki, J.; Daniel, A.V.; Ramayya, A.V.; Hwang, J.K.; Sandulescu, A.; Florescu, A.; Greiner, W. [Vanderbilt University, Nashville, Tennessee 37235 (United States); Ter-Akopian, G.M.; Daniel, A.V.; Florescu, A.; Greiner, W. [JIHIR, Oak Ridge, Tennessee 37831 (United States); Greiner, W. [ITP, J.W. Goethe University, D-60054, Frankfurt am Main (Germany); Florescu, A. [IAP, Bucharest, P.O. Box MG-6, (Russian Federation); Kliman, J.; Morhac, M. [IP SASc, Bratislava (Slovak Republic); Rasmussen, J.O. [LBNL, Berkeley, California 94720 (United States); Stoyer, M.A. [LLNL, Livermore , California 94550 (United States); Cole, J.D. [INEL, Idaho Falls, Idaho 83415 (United States)

    1998-12-01

    Fragment angular momenta as a function of neutron multiplicity were extracted for the first time for the Mo-Ba and Zr-Ce charge splits of {sup 252}Cf by studying prompt coincident {gamma}-rays. The obtained primary fragment angular momenta do not continuously rise with the increase in the number of neutrons evaporated. In frame of the scission point bending oscillation model such regularity is explained due the decrease of the bending temperature. Adiabatic bending oscillations (T=0) are obtained at large ({nu}{sub tot}{gt}5) and small ({nu}{sub tot}=0) scission point elongation. These oscillations are excited to the temperature of 2{endash}3 MeV for the most probable scission configurations indicating a weak coupling between collective and internal degrees of freedom. A strong coupling between the collective bending and dipole oscillations was found. {copyright} {ital 1998 American Institute of Physics.}

  10. A search for back-to-back e+e- pairs in the spontaneous-fission disintegration of 252Cf

    International Nuclear Information System (INIS)

    Tsunoda, T.; Nakamura, S.; Orito, S.; Minowa, M.

    1995-01-01

    A back-to-back electron-positron pair is searched for in spontaneous-fission disintegration of 252 Cf. The emission of such a pair, if observed, might be a manifestation of production and prompt decay of a heretofore unknown neutral particle. The emission rate of such a pair is found to be less than (2.5-5.5) . 10 -10 per fission at the 95% confidence level depending on the mass of the hypothetical particle which is between 40 and 200 MeV/c 2 . (orig.)

  11. Specification of brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-01

    BCRU recommends that the following specification of gamma-ray brachytherapy sources be adopted. Unless otherwise stated, the output of a cylindrical source should be specified in air kerma rate at a point in free space at a distance of 1 m from the source on the radial plane of symmetry, i.e. the plane bisecting the active length and perpendicular to the cylindrical axis of the source. For a wire source the output should be specified for a 1 cm length. For any other construction of source, the point at which the output is specified should be stated. It is also recommended that the units in which the air kerma rate is expressed should be micrograys per hour (..mu..Gy/h).

  12. Procedures for calibration of brachytherapy sources

    International Nuclear Information System (INIS)

    Alfonso Laguardia, R.; Alonso Samper, J.L.; Morales Lopez, J.L.; Saez Nunez, D.G.

    1997-01-01

    Brachytherapy source strength verification is a responsibility of the user of these source, in fact of the Medical Physicists in charge of this issue in a Radiotherapy Service. The calibration procedures in the users conditions are shown. Specifics methods for source strength determination are recommended, both for High Dose Rate (HDR) sources with Remote Afterloading equipment and for Low Dose Rate sources. The The results of the calibration of HDR Remote After loaders are indicated

  13. Study of scission shapes in spontaneous ternary fission of 252Cf

    International Nuclear Information System (INIS)

    Singer, P.; Schwalm, D.; Thirolf, P.; Goennenwein, F.; Hesse, M.

    1995-06-01

    A new kinematic study on the ternary fission of 252 Cf has been conducted by registering prompt neutrons and fission γ rays coincidence with light charged particles (LCP) and fission fragments. The aim is to investigate changes in fragment deformation energy between the binary and ternary fission modes from measured prompt neutron angular distributions and multiplicities, and to explore the influence of light particle emission on the energy distribution, multiplicity and angular anisotropy of γ rays emitted during fragment de-excitation. The experiment was performed at the MPI Heidelberg using the Darmstadt-Heidelberg crystal ball spectrometer as γ-ray and neutron detector. Fragments were identified by a double-E measurement with an angular sensitive twin ionization chamber (IC). Light charged particles from fission were measured by ΔE-E telescopes composed of ΔE ICs and silicon PIN diodes. The telescopes enable to identify various LCPs which are emitted much more rarely than ternary α particles. The parameters of the experiment and the method of data analysis are described and first results presented. (orig.)

  14. CF3CH(ONO)CF3: Synthesis, IR spectrum, and use as OH radical source for kinetic and mechanistic studies

    DEFF Research Database (Denmark)

    Andersen, Mads Peter Sulbæk; Hurley, MD; Ball, JC

    2003-01-01

    The synthesis, IR spectrum, and first-principles characterization of CF3CH(ONO)CF3 as well as its use as an OH radical source in kinetic and mechanistic studies are reported. CF3CH(ONO)CF3 exists in two conformers corresponding to rotation about the RCO-NO bond. The more prevalent trans conformer......C(O)CF3 and, by implication, OH radicals in 100% yield. CF3CH(ONO)CF3 photolysis is a convenient source of OH radicals in the studies of the yields of CO, CO2, HCHO, and HC(O)OH products which can be difficult to measure using more conventional OH radical sources (e.g., CH3ONO photolysis). CF3CH...

  15. Prompt neutron spectrum of the spontaneous fission of californium-252

    International Nuclear Information System (INIS)

    Zamyatnin, Yu.S.; Kroshkin, N.I.; Korostylev, V.A.; Nefedov, V.N.; Ryazanov, D.K.; Starostov, B.I.; Semenov, A.F.

    1976-01-01

    The californium-252 spontaneous fission neutron spectrum was measured in the energy range of 0.01 to 10 MeV by the time-of-flight technique using various neutron detectors. The measurements of 252 Cf neutron spectrum at energies of 0.01 to 5 MeV were performed as a function of fission fragment kinetic energy. The mean neutron spectrum energy in the range of 0.7 to 10 MeV was found from the results of measurements. The irregularity in the 252 Cf neutron spectrum in the neutron energy range of less than 0.7 MeV compared to theoretical values is discussed. The mechanism of 252 Cf neutron emission is also discussed on the basis of neutron yield angle measurements. 12 references

  16. Guidelines for the calibration of low energy photon sources at beta-ray brachytherapy sources

    International Nuclear Information System (INIS)

    2000-01-01

    With the development of improved methods of implanting brachytherapy sources in a precise manner for treating prostate cancer and other disease processes, there has been a tremendous growth in the use of low energy photon sources, such as 125 I and 103 Pd brachytherapy seeds. Low energy photon sources have the advantage of easier shielding and also lowering the dose to normal tissue. However, the dose distributions around these sources are affected by the details in construction of the source and its encapsulation more than other sources used for brachytherapy treatments, such as 192 Ir. With increasing number of new low energy photon sources on the market, care should be taken with regard to its traceability to primary standards. It cannot be assumed that a calibration factor for an ionization chamber that is valid for one type of low energy photon source, automatically is valid for another source even if both would use the same isotope. Moreover, the method used to calculate the dose must also take into account the structure of the source and the encapsulation. The dose calculation algorithm that is valid for one type of low energy source may not be valid for another source even if in both cases the same radionuclide is used. Simple ''point source'' approximations, i.e. where the source is modeled as a point, should be avoided, as such methods do not account for any details in the source construction. In this document, the dose calculation formalism adopted for low energy photon sources is that recommended by the American Association of Physicists in Medicine (AAPM) as outlined by Task Group-43 (TG-43). This method accounts for the source and capsule geometry. The AAPM recommends brachytherapy photon sources to be specified in terms of 'Air Kerma Strength' that is also used in the formalism mentioned above. On the other hand, the International Commission on Radiation Units and Measurements (ICRU) recommends that the specification be done in terms of Reference Air

  17. Calculation of neutron and gamma-ray energy spectra in liquid air and liquid nitrogen due to 14-MeV neutron and californium-252 sources

    International Nuclear Information System (INIS)

    Straker, E.A.; Gritzner, M.L.; Harris, L. Jr.

    1978-01-01

    Calculations of neutron and gamma-ray fluences from 14-MeV neutron and 252 Cf sources in liquid air and liquid nitrogen have been performed. These calculations were made specifically for comparison with experimental data measured at Stohl, Federal Republic of Germany. The discrete-ordinates method was utilized with neutron and gamma-ray cross sections from ENDF/B-IV. One-dimensional calculational models were developed for the sources and tank. Limited comparisons are made with experimental data

  18. Charge distribution in the ternary fragmentation of {sup 252}Cf

    Energy Technology Data Exchange (ETDEWEB)

    Senthil Kannan, M.T.; Balasubramaniam, M. [Bharathiar University, Department of Physics, Coimbatore (India)

    2017-08-15

    We present here, for the first time, a study on ternary fragmentation charge distribution of {sup 252}Cf using the convolution integral method and the statistical theory. The charge distribution for all possible charge combinations of a ternary breakup are grouped as a bin containing different mass partitions. Different bins corresponding to various third fragments with mass numbers from A{sub 3} = 16 to 84 are identified with the available experimental masses. The corresponding potential energy surfaces are calculated using the three cluster model for the two arrangements A{sub 1} + A{sub 2} + A{sub 3} and A{sub 1} + A{sub 3} + A{sub 2}. The ternary fragmentation yield values are calculated for the ternary combination from each bin possessing minimum potential energy. The yields of the resulting ternary combinations as a function of the charge numbers of the three fragments are analyzed for both the arrangements. The calculations are carried out at different excitation energies of the parent nucleus. For each excitation energy the temperature of the three fragments are iteratively computed conserving the total energy. The distribution of fragment temperatures corresponding to different excitation energies for some fixed third fragments are discussed. The presence of the closed shell nucleus Sn in the favourable ternary fragmentation is highlighted. (orig.)

  19. Development of the Dutch primary standard for beta-emitting brachytherapy sources

    International Nuclear Information System (INIS)

    Marel, J. an der; Dijk, E. van

    2002-01-01

    The application of β-radiation emitting radioactive sources in medicine is rapidly expanding. An important new application is the use of β-radiation emitting radioactive sources in endovascular brachytherapy to avoid restenosis. Another well-known application is the use of the ophthalmic applicator (flat or concave surface source) for the treatment of tumors in the eye. Dose and dose distributions are very important characteristics of brachytherapy sources. The absorbed dose in the treated tissue should be known accurately to assure a good quality of the treatment and to develop new treatment methods and source configurations. At the Nederland s Meetinstituut (NMi) a project is going on for the development of a primary standard for betadosimetry. With this standard, dose and dose distributions of β-sources as used in brachytherapy can be measured in terms of absorbed dose to water. The primary standard is based on an extrapolation chamber. The extrapolation chamber will become part of a quality assurance system in Dutch hospitals for endovascular brachytherapy sources. The quality assurance system will further consist of transfer standards like well-type ionisation chambers, plastic scintillator systems and radiochromic film dosimetry. Apart from the endovascular sources the extrapolation chamber will be used to characterize ophthalmic applicators

  20. New isomeric states in {sup 152,154,156}Nd produced by spontaneous fission of {sup 252}Cf

    Energy Technology Data Exchange (ETDEWEB)

    Gautherin, C.; Houry, M.; Korten, W.; Le Coz, Y.; Lucas, R.; Phan, X.H.; Theisen, C. [Commissariat l`Energie Atomique de Saclay, Gif sur Yvette (France). DSM/DAPINA/SPhN; Badimon, C.; Barreau, G.; Doan, T.P.; Pedemay, G. [Centre d`Etudes Nucleaires de Bordeaux-Gradignan, Domaine du Haut Vigneau, F-33175 Gradignan (France); Belier, G.; Girod, M.; Meot, V.; Peru, S. [Commissariat a l`Energie Atomique de Bruyeres-le-Chatel, DAM/SPN, BP12, F-91680 Bruyeres-le-Chatel (France); Astier, A.; Ducroux, L.; Meyer, M.; Redon, N. [Institut de Physique Nucleaire de Lyon, F-69622 Villeurbanne Cedex (France)

    1998-04-01

    Isomeric states have been observed in fission-fragments produced by spontaneous fission of {sup 252}Cf. These states are found in neutron rich nuclei of different structure and deformations. About 50 isomeric nuclei have been observed using coincidences between {gamma}-rays identified in EUROGAM II and fission fragments detected in photovoltaic cells (SAPhIR). Lifetimes in the range from 20 ns to 2{mu}s have been measured. Presented calculations based on HFB+D1S force on new measured isomeric states in the {sup 152,154,156}Nd show evidence for K-isomers. (orig.) With 8 figs., 27 refs.

  1. 137Cs - Brachytherapy sources : a technology scenario

    International Nuclear Information System (INIS)

    Varma, R.N.

    2001-01-01

    Cancer has emerged as one of the major cause of morbidity and mortality all over the world. India houses world's second largest population and registers 4-5 lakhs new cancer cases every year. Cancer of cervix is most common form of malignancy among Indian women. Radiation therapy, especially intracavity brachytherapy in conjunction with other modalities like surgery, chemotherapy has been found to be highly effective for the management and control of cervical carcinoma at all stages. A technology has been developed indigenously for the fabrication of 137 Cs sources for brachytherapy applications

  2. Invited review, recent developments in brachytherapy source dosimetry

    International Nuclear Information System (INIS)

    Meigooni, A.S.

    2004-01-01

    Application of radioactive isotopes is the treatment of choice around the globe for many cancer sites. In this technique, the accuracy of the radiation delivery is highly dependent on the accuracy of radiation dosimetry around individual brachytherapy sources. Moreover, in order to have compatible clinical results, an identical method of source dosimetry must be employed across the world. This problem has been recently addressed by task group 43 from the American Association of Medical Physics with a protocol for dosimetric characterization of brachytherapy sources. This new protocol has been further updated using published data from international sources, by a new Task Group from the American Association of Medical Physics. This has resulted in an updated protocol known as TG43U1 that has been published in March 2004 issue of Medical Physics. The goal of this presentation is to review the original Task Group 43 protocol and associated algorithms for brachytherapy source dosimetry. In addition, the shortcomings of the original protocol that has been resolved in the updated recommendation will be highlighted. I am sure that this is not the end of the line and more work is needed to complete this task. I invite the scientists to join this task and complete the project, with the hope of much better clinical results for cancer patients

  3. Analysis of the boron pile measurement of the average neutron yield per fission of 252Cf: (AWBA development program)

    International Nuclear Information System (INIS)

    Ullo, J.J.

    1977-08-01

    The Harwell Boron Pile measurement of the average number of prompt neutrons emitted per fission, ν-bar/sub p/, of 252 Cf was analyzed in detail by a Monte Carlo method. From the calculated energy dependence of the neutron detection efficiency a value of ν-bar/sub p/ = 3.733 +- 0.022 was obtained. This value is 0.76 percent higher than the original reported value of 3.705 +- 0.015. Possible causes for this increase are discussed. 3 figures, 6 tables

  4. Developing A Directional High-Dose Rate (d-HDR) Brachytherapy Source

    Science.gov (United States)

    Heredia, Athena Yvonne

    Conventional sources used in brachytherapy provide nearly isotropic or radially symmetric dose distributions. Optimizations of dose distributions have been limited to varied dwell times at specified locations within a given treatment volume, or manipulations in source position for seed implantation techniques. In years past, intensity modulated brachytherapy (IMBT) has been used to reduce the amount of radiation to surrounding sensitive structures in select intracavitary cases by adding space or partial shields. Previous work done by Lin et al., at the University of Wisconsin-Madison, has shown potential improvements in conformality for brachytherapy treatments using a directionally shielded low dose rate (LDR) source for treatments in breast and prostate. Directional brachytherapy sources irradiate approximately half of the radial angles around the source, and adequately shield a quarter of the radial angles on the opposite side, with sharp gradient zones between the treated half and shielded quarter. With internally shielded sources, the radiation can be preferentially emitted in such a way as to reduce toxicities in surrounding critical organs. The objective of this work is to present findings obtained in the development of a new directional high dose rate (d-HDR) source. To this goal, 103Pd (Z = 46) is reintroduced as a potential radionuclide for use in HDR brachytherapy. 103Pd has a low average photon energy (21 keV) and relatively short half -life (17 days), which is why it has historically been used in low dose rate applications and implantation techniques. Pd-103 has a carrier-free specific activity of 75000 Ci/g. Using cyclotron produced 103Pd, near carrier-free specific activities can be achieved, providing suitability for high dose rate applications. The evolution of the d-HDR source using Monte Carlo simulations is presented, along with dosimetric parameters used to fully characterize the source. In addition, a discussion on how to obtain elemental

  5. Spectroscopic characterization of low dose rate brachytherapy sources

    Science.gov (United States)

    Beach, Stephen M.

    The low dose rate (LDR) brachytherapy seeds employed in permanent radioactive-source implant treatments usually use one of two radionuclides, 125I or 103Pd. The theoretically expected source spectroscopic output from these sources can be obtained via Monte Carlo calculation based upon seed dimensions and materials as well as the bare-source photon emissions for that specific radionuclide. However the discrepancies resulting from inconsistent manufacturing of sources in comparison to each other within model groups and simplified Monte Carlo calculational geometries ultimately result in undesirably large uncertainties in the Monte Carlo calculated values. This dissertation describes experimentally attained spectroscopic outputs of the clinically used brachytherapy sources in air and in liquid water. Such knowledge can then be applied to characterize these sources by a more fundamental and metro logically-pure classification, that of energy-based dosimetry. The spectroscopic results contained within this dissertation can be utilized in the verification and benchmarking of Monte Carlo calculational models of these brachytherapy sources. This body of work was undertaken to establish a usable spectroscopy system and analysis methods for the meaningful study of LDR brachytherapy seeds. The development of a correction algorithm and the analysis of the resultant spectroscopic measurements are presented. The characterization of the spectrometer and the subsequent deconvolution of the measured spectrum to obtain the true spectrum free of any perturbations caused by the spectrometer itself is an important contribution of this work. The approach of spectroscopic deconvolution that was applied in this work is derived in detail and it is applied to the physical measurements. In addition, the spectroscopically based analogs to the LDR dosimetry parameters that are currently employed are detailed, as well as the development of the theory and measurement methods to arrive at these

  6. Time-of-flight mass spectrometer with 252Cf surface ionisation coupled with high-pressure liquid chromatography for determining pharmaceutical substances in the blood

    International Nuclear Information System (INIS)

    Danigel, H.

    1983-01-01

    Cf-252 PDMS is well suited for routine applications and can be combined with HPLC. This combined analytical system can be used for measuring the concentrations of pharmaceutical substances in body fluids on the basis of an internal standard. The results (pharmacokinetics, metabolism) indicate the necessary therapeutical dose and the efficacy of the substance applied. (DG) [de

  7. Study of ternary and quaternary spontaneous fission of 252Cf with the NESSI detector

    International Nuclear Information System (INIS)

    Tishchenko, V.G.; Jahnke, U.; Herbach, C.M.; Hilscher, D.

    2002-11-01

    Ternary and quaternary spontaneous decay of 252 Cf was studied with the NESSI detector, a combination of two 4π detectors for charged particles, neutrons and γ-rays. The applied method of particle identification by measuring the energies and relative time-of-flights of the decay products is shown to be very effective for the study of rare decay modes. The energy and angular distributions of the decay products, the associated neutron multiplicities, the total energy of the prompt γ-radiation as well as correlations between the various observables were measured for the first time in a single full-scale experiment. The characteristics of ternary fission known from previous investigations are confirmed in the frame of a methodically independent experiment. Preliminary estimates of the quaternary fission yield are presented. An attempt is made to determine the mechanism of quaternary fission. (orig.)

  8. Fabrication of intense neutron sources for medical applications

    International Nuclear Information System (INIS)

    Boulogne, A.R.; Walker, V.W.

    1975-01-01

    Simulated sources containing 252 Cf equivalents of 0.1 to 1.0 milligrams were prepared. Samarium was used as the simulant in a modified chemical plating technique similar to that used to prepare palladium-californium oxide cermet for industrial applications. The length of the platinum-10 percent iridium doubly encapsulated source with its protective sheath is 0.545 in. (14.1 mm). Outside dia of the source, including its sheath, is 0.109 in. (2.8 mm). Existing ''Brachytrons'' can accommodate this source form. This capsule system will withstand internal gas pressures from helium due to alpha decay and fission gases from a 1 mg 252 Cf source after ten years if the source is subjected to a maximum temperature of 800 0 C, the theoretical temperature of an accidental fire. Under these conditions the safety factor is 3. The capsule system is being tested with tracer amounts of 252 Cf to ensure that it will withstand adverse service conditions as well as tests specified for Special Form Materials. (auth)

  9. {sup 252}Cf spontaneous prompt fission neutron spectrum measured at 0 degree and 180 degree relative to the fragment motion

    Energy Technology Data Exchange (ETDEWEB)

    Shanglian, Bao; Jinquan, Liu [Beijing Univ., BJ (China); Batenkov, O I; Blinov, M V; Smirnov, S N [V.G. Khlopin Radium Institute, ST. Petersburg (Russian Federation)

    1994-09-01

    The {sup 252}Cf spontaneous prompt fission neutron spectrum at 0 degree and 180 degree relative to the motion direction of corresponding fission fragments was measured. High angular resolution for fragment measurements and high energy resolution for neutron measurements were obtained using multi-parameter TOF spectrometer. The results showed that there is a symmetric distribution of `forward` and `backward` for low energy in C.M.S. neutrons, which was an evidence of nonequilibrium neutrons existed in fission process.

  10. Absolute measurement of ν/sub p/-bar for 252Cf by the large liquid scintillator tank technique

    International Nuclear Information System (INIS)

    Spencer, R.R.

    1979-01-01

    A vigorous effect to dispel the scandal of the approx. 2% dispersion in reported experimental values of 252 Cf ν-bar, the average number of neutrons emitted in spontaneous fission, has been underway over the past 5 years. The goal is to reduce the uncertainty in this fundamental parameter to the +- 0.25% level needed for reactor physics applications. Both new measurements and revaluation of older measurements are involved. At ORNL a new measurement is being carried out using the leage liquid scintillator neutron detector. Findings of the most recent experiment, incorporating improvements suggested in a preliminary study are discussed. 6 figures, 2 tables

  11. Health physics aspects of 252Cf

    International Nuclear Information System (INIS)

    Bhagwat, A.M.

    1974-01-01

    After briefly describing the methods of production, radioactive, chemical and biological properties of californium-252, its health physics aspects are reviewed in detail. Its external and internal radiation hazards can be minimised through control of radiation and contamination and proper shield design. Use of various shielding materials is evaluated. The following aspects are also discussed : (1) radiation detectors for neutrons and gamma radiation (2) personnel monitoring techniques (3) bioassay and (4) storage and transportation. (M.G.B.)

  12. Analysis of linear energy transfers and quality factors of charged particles produced by spontaneous fission neutrons from 252Cf and 244Pu in the human body

    International Nuclear Information System (INIS)

    Endo, A.; Sato, T.

    2013-01-01

    Absorbed doses, linear energy transfers (LETs) and quality factors of secondary charged particles in organs and tissues, generated via the interactions of the spontaneous fission neutrons from. 252 Cf and. 244 Pu within the human body, were studied using the Particle and Heavy Ion Transport Code System (PHITS) coupled with the ICRP Reference Phantom. Both the absorbed doses and the quality factors in target organs generally decrease with increasing distance from the source organ. The analysis of LET distributions of secondary charged particles led to the identification of the relationship between LET spectra and target-source organ locations. A comparison between human body-averaged mean quality factors and fluence-averaged radiation weighting factors showed that the current numerical conventions for the radiation weighting factors of neutrons, updated in ICRP103, and the quality factors for internal exposure are valid. (authors)

  13. Gamma-ray multiplicity distribution in ternary fission of {sup 252}Cf

    Energy Technology Data Exchange (ETDEWEB)

    Jandel, M [Department of Nuclear Physics, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava (Slovakia); Kliman, J [Department of Nuclear Physics, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava (Slovakia); Krupa, L [Department of Nuclear Physics, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava (Slovakia); Morhac, M [Department of Nuclear Physics, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava (Slovakia); Hamilton, J H [Department of Physics, Vanderbilt University, Nashville, TN (United States); Kormicki, J [Department of Physics, Vanderbilt University, Nashville, TN (United States); Ramayya, A V [Department of Physics, Vanderbilt University, Nashville, TN (United States); Hwang, J K [Department of Physics, Vanderbilt University, Nashville, TN (United States); Luo, Y X [Department of Physics, Vanderbilt University, Nashville, TN (United States); Fong, D [Department of Physics, Vanderbilt University, Nashville, TN (United States); Gore, P [Department of Physics, Vanderbilt University, Nashville, TN (United States); Akopian, G M Ter; Oganessian, Yu Ts; Rodin, A M; Fomichev, A S; Popeko, G S; Daniel, A V [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna (Russian Federation); Rasmussen, J O; Macchiavelli, A O [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Stoyer, M A [Lawrence Livermore National Laboratory, Livermore, CA (United States); Donangelo, R [Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21945-970 Rio de Janeiro (Brazil); Cole, J D [Idaho National Engineering and Environmental Laboratory, Idaho Falls, ID (United States)

    2002-12-01

    From multiparameter data obtained at Lawrence Berkeley National Laboratory, the integral characteristics of the prompt {gamma}-ray emission were extracted for tripartition of {sup 252}Cf with He, Be and C being the third light charged particle. We used multifold {gamma}-ray coincidence spectra for the determination of {gamma}-ray multiplicities assuming a Gaussian distribution for {gamma}-ray multiplicity. The multiplicity distribution characteristics, i.e. mean multiplicity and its dispersion were obtained by minimizing with respect to the calculated values of probabilities of multifold {gamma}-ray coincidences using a combinatoric method. Comparison with the known experimental data from binary fission was made. Further, we investigated dependencies of the mean {gamma}-ray multiplicity on the kinetic energy of the light charged particle. The mean {gamma}-ray multiplicity for He ternary fission is found to increase rapidly with increasing kinetic energy of He in the region less than 11 MeV and then decrease slowly with increasing kinetic energy of He. The anomalous behaviour of {gamma}-ray emission is discussed. The mean {gamma}-ray multiplicity was determined for the first time for Be and C ternary fission. For Be, the {gamma}-ray multiplicity as a function of kinetic energy was obtained as well.

  14. Study of two different radioactive sources for prostate brachytherapy treatment

    International Nuclear Information System (INIS)

    Pereira Neves, Lucio; Perini, Ana Paula; Souza Santos, William de; Caldas, Linda V.E.; Belinato, Walmir

    2015-01-01

    In this study we evaluated two radioactive sources for brachytherapy treatments. Our main goal was to quantify the absorbed doses on organs and tissues of an adult male patient, submitted to a brachytherapy treatment with two radioactive sources. We evaluated a 192 Ir and a 125 I radioactive sources. The 192 Ir radioactive source is a cylinder with 0.09 cm in diameter and 0.415 cm long. The 125 I radioactive source is also a cylinder, with 0.08 cm in diameter and 0.45 cm long. To evaluate the absorbed dose distribution on the prostate, and other organs and tissues of an adult man, a male virtual anthropomorphic phantom MASH, coupled in the radiation transport code MCNPX 2.7.0, was employed.We simulated 75, 90 and 102 radioactive sources of 125 I and one of 192 Ir, inside the prostate, as normally used in these treatments, and each treatment was simulated separately. As this phantom was developed in a supine position, the displacement of the internal organs of the chest, compression of the lungs and reduction of the sagittal diameter were all taken into account. For the 192 Ir, the higher doses values were obtained for the prostate and surrounding organs, as the colon, gonads and bladder. Considering the 125 I sources, with photons with lower energies, the doses to organs that are far from the prostate were lower. All values for the dose rates are in agreement with those recommended for brachytherapy treatments. Besides that, the new seeds evaluated in this work present usefulness as a new tool in prostate brachytherapy treatments, and the methodology employed in this work may be applied for other radiation sources, or treatments. (authors)

  15. Study of two different radioactive sources for prostate brachytherapy treatment

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Neves, Lucio; Perini, Ana Paula [Instituto de Fisica, Universidade Federal de Uberlandia, Caixa Postal 593, 38400-902, Uberlandia, MG (Brazil); Souza Santos, William de; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares, Comissao Nacional de Energia Nuclear, IPENCNEN/SP, Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo, SP (Brazil); Belinato, Walmir [Departamento de Ensino, Instituto Federal de Educacao, Ciencia e Tecnologia da Bahia, Campus Vitoria da Conquista, Zabele, Av. Amazonas 3150, 45030-220 Vitoria da Conquista, BA (Brazil)

    2015-07-01

    In this study we evaluated two radioactive sources for brachytherapy treatments. Our main goal was to quantify the absorbed doses on organs and tissues of an adult male patient, submitted to a brachytherapy treatment with two radioactive sources. We evaluated a {sup 192}Ir and a {sup 125}I radioactive sources. The {sup 192}Ir radioactive source is a cylinder with 0.09 cm in diameter and 0.415 cm long. The {sup 125}I radioactive source is also a cylinder, with 0.08 cm in diameter and 0.45 cm long. To evaluate the absorbed dose distribution on the prostate, and other organs and tissues of an adult man, a male virtual anthropomorphic phantom MASH, coupled in the radiation transport code MCNPX 2.7.0, was employed.We simulated 75, 90 and 102 radioactive sources of {sup 125}I and one of {sup 192}Ir, inside the prostate, as normally used in these treatments, and each treatment was simulated separately. As this phantom was developed in a supine position, the displacement of the internal organs of the chest, compression of the lungs and reduction of the sagittal diameter were all taken into account. For the {sup 192}Ir, the higher doses values were obtained for the prostate and surrounding organs, as the colon, gonads and bladder. Considering the {sup 125}I sources, with photons with lower energies, the doses to organs that are far from the prostate were lower. All values for the dose rates are in agreement with those recommended for brachytherapy treatments. Besides that, the new seeds evaluated in this work present usefulness as a new tool in prostate brachytherapy treatments, and the methodology employed in this work may be applied for other radiation sources, or treatments. (authors)

  16. Californium-252: isotope for modern radiotherapy of cervix, uterine and vaginal carcinomas

    International Nuclear Information System (INIS)

    Maruyama, J.; Beach, J.L.; Nagell, J.R. van

    1984-01-01

    Cf-252 is an isotope that can easily be afterloaded into available gynecological applicators and used for bulky cervix, uterus or vaginal cancer therapy. It is economical, time and cost effective in use, and can be applied to the therapy of many patients throughout the world. It is more effective for neutron therapy than machine fast neutron therapy and is the only form of neutron therapy producing consistent complication-free 5-year cure of advanced cancers currently available. Cf-252 is an isotope for modern gynecological tumor therapy for the future. Isodose curves for Cf-252 implants revealed dose distributions conforming well to tumor. (orig.) [de

  17. Historical review of californium-252 discovery and development

    International Nuclear Information System (INIS)

    Stoddard, D.H.

    1985-01-01

    This paper discusses the discovery and history of californium 252. This isotope may be synthesized by irradiating plutonium 239, plutonium 242, americium 243, or curium 244 with neutrons in a nuclear reactor. Various experiments and inventions involving 252 Cf conducted at the Savannah River Plant are discussed. The evolution of radiotherapy using californium 252 is reviewed

  18. Determining profile of dose distribution for PD-103 brachytherapy source

    International Nuclear Information System (INIS)

    Berkay, Camgoz; Mehmet, N. Kumru; Gultekin, Yegin

    2006-01-01

    Full text: Brachytherapy is a particular radiotherapy for cancer treatments. By destructing cancerous cells using radiation, the treatment proceeded. When alive tissues are subject it is hazardous to study experimental. For brachytherapy sources generally are studied as theoretical using computer simulation. General concept of the treatment is to locate the radioactive source into cancerous area of related tissue. In computer studies Monte Carlo mathematical method that is in principle based on random number generations, is used. Palladium radioisotope is LDR (Low radiation Dose Rate) source. Main radioactive material was coated with titanium cylinder with 3mm length, 0.25 mm radius. There are two parts of Pd-103 in the titanium cylinder. It is impossible to investigate differential effects come from two part as experimental. Because the source dimensions are small compared with measurement distances. So there is only simulation method. In dosimetric studies it is aimed to determine absorbed dose distribution in tissue as radial and angular. In nuclear physics it is obligation to use computer based methods for researchers. Radiation studies have hazards for scientist and people interacted with radiation. When hazard exceed over recommended limits or physical conditions are not suitable (long work time, non economical experiments, inadequate sensitivity of materials etc.) it is unavoidable to simulate works and experiments before practices of scientific methods in life. In medical area, usage of radiation is required computational work for cancer treatments. Some computational studies are routine in clinics and other studies have scientific development purposes. In brachytherapy studies there are significant differences between experimental measurements and theoretical (computer based) output data. Errors of data taken from experimental studies are larger than simulation values errors. In design of a new brachytherapy source it is important to consider detailed

  19. Effect of photon energy spectrum on dosimetric parameters of brachytherapy sources.

    Science.gov (United States)

    Ghorbani, Mahdi; Mehrpouyan, Mohammad; Davenport, David; Ahmadi Moghaddas, Toktam

    2016-06-01

    The aim of this study is to quantify the influence of the photon energy spectrum of brachytherapy sources on task group No. 43 (TG-43) dosimetric parameters. Different photon spectra are used for a specific radionuclide in Monte Carlo simulations of brachytherapy sources. MCNPX code was used to simulate 125I, 103Pd, 169Yb, and 192Ir brachytherapy sources. Air kerma strength per activity, dose rate constant, radial dose function, and two dimensional (2D) anisotropy functions were calculated and isodose curves were plotted for three different photon energy spectra. The references for photon energy spectra were: published papers, Lawrence Berkeley National Laboratory (LBNL), and National Nuclear Data Center (NNDC). The data calculated by these photon energy spectra were compared. Dose rate constant values showed a maximum difference of 24.07% for 103Pd source with different photon energy spectra. Radial dose function values based on different spectra were relatively the same. 2D anisotropy function values showed minor differences in most of distances and angles. There was not any detectable difference between the isodose contours. Dosimetric parameters obtained with different photon spectra were relatively the same, however it is suggested that more accurate and updated photon energy spectra be used in Monte Carlo simulations. This would allow for calculation of reliable dosimetric data for source modeling and calculation in brachytherapy treatment planning systems.

  20. Equivalent properties of single event burnout induced by different sources

    International Nuclear Information System (INIS)

    Yang Shiyu; Cao Zhou; Da Daoan; Xue Yuxiong

    2009-01-01

    The experimental results of single event burnout induced by heavy ions and 252 Cf fission fragments in power MOSFET devices have been investigated. It is concluded that the characteristics of single event burnout induced by 252 Cf fission fragments is consistent to that in heavy ions. The power MOSFET in the 'turn-off' state is more susceptible to single event burnout than it is in the 'turn-on' state. The thresholds of the drain-source voltage for single event burnout induced by 173 MeV bromine ions and 252 Cf fission fragments are close to each other, and the burnout cross section is sensitive to variation of the drain-source voltage above the threshold of single event burnout. In addition, the current waveforms of single event burnouts induced by different sources are similar. Different power MOSFET devices may have different probabilities for the occurrence of single event burnout. (authors)

  1. Calibration of Photon Sources for Brachytherapy

    Science.gov (United States)

    Rijnders, Alex

    Source calibration has to be considered an essential part of the quality assurance program in a brachytherapy department. Not only it will ensure that the source strength value used for dose calculation agrees within some predetermined limits to the value stated on the source certificate, but also it will ensure traceability to international standards. At present calibration is most often still given in terms of reference air kerma rate, although calibration in terms of absorbed dose to water would be closer to the users interest. It can be expected that in a near future several standard laboratories will be able to offer this latter service, and dosimetry protocols will have to be adapted in this way. In-air measurement using ionization chambers (e.g. a Baldwin—Farmer ionization chamber for 192Ir high dose rate HDR or pulsed dose rate PDR sources) is still considered the method of choice for high energy source calibration, but because of their ease of use and reliability well type chambers are becoming more popular and are nowadays often recommended as the standard equipment. For low energy sources well type chambers are in practice the only equipment available for calibration. Care should be taken that the chamber is calibrated at the standard laboratory for the same source type and model as used in the clinic, and using the same measurement conditions and setup. Several standard laboratories have difficulties to provide these calibration facilities, especially for the low energy seed sources (125I and 103Pd). Should a user not be able to obtain properly calibrated equipment to verify the brachytherapy sources used in his department, then at least for sources that are replaced on a regular basis, a consistency check program should be set up to ensure a minimal level of quality control before these sources are used for patient treatment.

  2. Clinical Practice and Quality Assurance Challenges in Modern Brachytherapy Sources and Dosimetry

    International Nuclear Information System (INIS)

    Butler, Wayne M.; Merrick, Gregory S.

    2008-01-01

    Modern brachytherapy has led to effective treatments through the establishment of broadly applicable dosimetric thresholds for maximizing survival with minimal morbidity. Proper implementation of recent dosimetric consensus statements and quality assurance procedures is necessary to maintain the established level of safety and efficacy. This review classifies issues as either 'systematic' or 'stochastic' in terms of their impact on large groups or individual patients, respectively. Systematic changes affecting large numbers of patients occur infrequently and include changes in source dosimetric parameters, prescribing practice, dose calculation formalism, and improvements in calculation algorithms. The physicist must be aware of how incipient changes accord with previous experience. Stochastic issues involve procedures that are applied to each patient individually. Although ample guidance for quality assurance of brachytherapy sources exists, some ambiguities remain. The latest American Association of Physicists in Medicine guidance clarifies what is meant by independent assay, changes source sampling recommendations, particularly for sources in sterile strands and sterile preassembled needles, and modifies action level thresholds. The changing environment of brachytherapy has not changed the fact that the prime responsibility for quality assurance in brachytherapy lies with the institutional medical physicist

  3. Structures of the neutron-rich nuclei observed in fission of {sup 252}Cf

    Energy Technology Data Exchange (ETDEWEB)

    Ramayya, A. V.; Hamilton, J. H.; Goodin, C. J.; Brewer, N. T.; Hwang, J. K. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Luo, Y. X. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 USA and Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Liu, S. H. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 USA and UNRIB/Oak Ridge Associated Universities, Oak Ridge, Tennessee 37831 (United States); Rasmussen, J. O.; Lee, I. Y. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Stone, N. J. [Department of Physics, Oxford University, Oxford OX1 3PU (United Kingdom); Daniel, A. V. [Flerov Laboratory of Nuclear Reactions, JINR, Dubna (Russian Federation); Zhu, S. J. [Department of Physics, Tsinghua University, Beijing 100084 (China)

    2014-08-14

    Analysis of high statistics triple coincidence fission γ data from {sup 252}Cf at Gammasphere including angular correlations yielded well-expanded high-spin level schemes with more complete and reliable spin/parity assignments for {sup 82}Ge, {sup 118,120,122}Cd and {sup 114,115}Rh. Both the quasi-particle/hole couplings and quasi-rotational degrees of freedom are implied to play roles in these Cd isotopes. Evidence for triaxial shapes and octupole components in the Cd isotopes is presented. These Cd isotopes may have triaxial deformations. High-spin level schemes of {sup 114,115}Rh have been established for the first time. The existence of a relatively large signature splitting and an yrare band shows typical features of a triaxially deformed nucleus. Possible excited deformed rotational bands are observed, for the first time, in {sup 82}Ge. From the multipole mixing ratio measurement, the ground state configurations of {sup 109,111}Ru, as well as excited states in {sup 103,107}Mo and {sup 111}Ru were determined.

  4. A search for fine structure of the time-of-flight spectrum of the fission neutrons of 252Cf

    International Nuclear Information System (INIS)

    Scobie, J.; Scott, R.D.; Feather, N.; Vass, D.G.

    1977-01-01

    A standard time-of-flight arrangement, in which start pulses were supplied by fission fragments and stop pulses by neutrons, has been employed in an attempt to check recent claims of the existence of fine structures in the time-of-flight spectrum of the fission neutrons of 252 Cf. This structure, in the form of spikes with tails towards longer times, has been attributed to the emission of neutrons of short delay (with half-lives of a few to a hundred or so nanoseconds) in the fission process. It has not been possible to find any convincing evidence for the existence of such structure. (author)

  5. In situ x-ray fluorescence and californium-252 neutron activation analysis for marine and terrestrial mineral exploration

    International Nuclear Information System (INIS)

    Wogman, N.A.

    1976-12-01

    Instrumentation has been designed for in situ analysis of marine and terrestrial minerals using the techniques of x-ray fluorescence and neutron activation analysis. The energy-dispersive x-ray fluorescence analyzer allows more than 20 elements to be quantitatively measured at the 10 ppM level in water depths to 300 m. The analyzer consists of a solid cryogen-cooled Si(Li) detector, a 50 mCi 109 Cd or 57 Co excitation source, and an analyzer-computer system for data storage and manipulation. The neutron activation analysis, which is designed to measure up to 30 elements at parts per hundred to ppM levels, utilizes the man-made element 252 Cf as its neutron activation source. The resulting radioelements which emit characteristic gamma radiation are then analyzed in situ during 2- to 200-s counting intervals with Ge(Li) or NaI(T1) detector systems. An extension of this latter technique, which uses a 252 Cf- 235 U fueled subcritical multiplier, is also being studied. The subcritical facility allows the neutrons from the 252 Cf source to be multiplied, thus providing greater neutron flux. Details of these in situ analysis systems, actual in situ spectra, and recorded data are discussed with respect to the detection of minerals at their varying concentration levels. The system response of each illustrates its usefulness for various rapid environmental mineral exploration studies. These techniques can be utilized on terrestrial surfaces and marine or fresh water sediments. 5 figures, 2 tables

  6. Distinct difference in relative biological effectiveness of 252Cf neutrons for the induction of mitotic crossing over and intragenic reversion of the white-ivory allele in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Yoshikawa, Isao; Hoshi, Masaharu; Ikenaga, Mituo

    1996-01-01

    The relative biological effectiveness (RBE) of 252 Cf neutrons was determined for two different types of somatic mutations, i.e., loss of heterozygosity for wing-hair mutations and reversion of the mutant white-ivory eye-color, in Drosophila melanogaster. Loss of heterozygosity for wing-hair mutations results predominantly from mitotic crossing over induced in wing anlage cells of larvae, while the reverse mutation of eye-color is due to an intragenic structural change in the white locus on the X-chromosome. For a quantitative comparison of RBE values for these events, we have constructed a combined mutation assay system so that induced mutant wing-hair clones as well as revertant eye-color clones can be detected simultaneously in the same individuals. Larvae were irradiated at the age of 80±4 h post-oviposition with 252 Cf neutrons or 137 Cs γ-rays, and male adult flies were examined under the microscope for the presence of the two types of clonal mosaic spots appearing. The induction of wing-hair spots per dose unit was much greater for 252 Cf neutrons than for 137 Cs γ -rays, whereas the frequencies of eye-color reversion were similar for neutrons and γ-rays. The estimated RBE values of neutrons were 8.5 and 1.2 for the induction of mutant wing-hair spots and revertant eye-color spots, respectively. These results indicate that the RBE of neutrons is much greater for mitotic crossing over in comparison to the intragenic white-ivory reversion events. Possible causes for the difference in RBE are discussed

  7. Source position verification and dosimetry in HDR brachytherapy using an EPID

    International Nuclear Information System (INIS)

    Smith, R. L.; Taylor, M. L.; McDermott, L. N.; Franich, R. D.; Haworth, A.; Millar, J. L.

    2013-01-01

    Purpose: Accurate treatment delivery in high dose rate (HDR) brachytherapy requires correct source dwell positions and dwell times to be administered relative to each other and to the surrounding anatomy. Treatment delivery inaccuracies predominantly occur for two reasons: (i) anatomical movement or (ii) as a result of human errors that are usually related to incorrect implementation of the planned treatment. Electronic portal imaging devices (EPIDs) were originally developed for patient position verification in external beam radiotherapy and their application has been extended to provide dosimetric information. The authors have characterized the response of an EPID for use with an 192 Ir brachytherapy source to demonstrate its use as a verification device, providing both source position and dosimetric information.Methods: Characterization of the EPID response using an 192 Ir brachytherapy source included investigations of reproducibility, linearity with dose rate, photon energy dependence, and charge build-up effects associated with exposure time and image acquisition time. Source position resolution in three dimensions was determined. To illustrate treatment verification, a simple treatment plan was delivered to a phantom and the measured EPID dose distribution compared with the planned dose.Results: The mean absolute source position error in the plane parallel to the EPID, for dwells measured at 50, 100, and 150 mm source to detector distances (SDD), was determined to be 0.26 mm. The resolution of the z coordinate (perpendicular distance from detector plane) is SDD dependent with 95% confidence intervals of ±0.1, ±0.5, and ±2.0 mm at SDDs of 50, 100, and 150 mm, respectively. The response of the EPID is highly linear to dose rate. The EPID exhibits an over-response to low energy incident photons and this nonlinearity is incorporated into the dose calibration procedure. A distance (spectral) dependent dose rate calibration procedure has been developed. The

  8. Sci-Thur PM – Brachytherapy 04: Commissioning and Implementation of a Cobalt-60 High Dose Rate Brachytherapy Source

    Energy Technology Data Exchange (ETDEWEB)

    Dysart, Jonathan [Horizon Health Network (Canada)

    2016-08-15

    An Eckert & Ziegler Bebig Co0.A86 cobalt 60 high dose rate (HDR) brachytherapy source was commissioned for clinical use. Long-lived Co-60 HDR sources offer potential logistical and economic advantages over Ir-192 sources, and should be considered for low to medium workload brachytherapy departments where modest increases in treatment times are not a factor. In optimized plans, the Co-60 source provides a similar dose distribution to Ir-192 despite the difference in radiation energy. By switching to Co-60, source exchange frequency can be reduced by a factor of 20, resulting in overall financial savings of more than 50% compared to Ir-192 sources. In addition, a reduction in Physicist QA workload of roughly 200 hours over the 5 year life of the Co-60 source is also expected. These benefits should be considered against the modest increases in average treatment time compared to those of Ir-192 sources, as well as the centre-specific needs for operating room shielding modification.

  9. Nuclear isomerism in fission fragments produced by the spontaneous fission of {sup 252}Cf; Isomerisme nucleaire dans les fragments de fission produits dans la fission spontanee du {sup 252}Cf

    Energy Technology Data Exchange (ETDEWEB)

    Gautherin, C

    1997-09-01

    This thesis is devoted to the study of the nuclear structure of neutron-rich nuclei, via the search of isomeric nuclear states. Neutron-rich nuclei were produced in the spontaneous fission of {sup 252}Cf. The experimental study of isomeric states in these nuclei was performed with the {gamma}-array EUROGAM II, coupled to an additional and original fission fragment detector composed by photovoltaic cells, SAPhIR. The photovoltaic cells are well adapted to detect low energy heavy ions and have good energy and time resolutions to obtain a good fission fragment detection. This experiment led to the discovery of new isomeric states in {sup 135}Xe, {sup 104}Mo, {sup 146,147,148}Ce and {sup 152,154,156}Nd, with lifetimes between 60 ns and 2 {mu}s. Level schemes of these nuclei have been completed. An interpretation of the isomeric states in the nuclei {sup 154,156}Nd and {sup 156,158}Sm was performed by Hartree-Fock-Bogolyubov calculations using the DIS Gogny force with two quasi-particles excitations. The confrontation with the experimental results led to an interpretation of these isomeric states as K-isomers. (author)

  10. Tracking brachytherapy sources using emission imaging with one flat panel detector

    International Nuclear Information System (INIS)

    Song Haijun; Bowsher, James; Das, Shiva; Yin Fangfang

    2009-01-01

    This work proposes to use the radiation from brachytherapy sources to track their dwell positions in three-dimensional (3D) space. The prototype device uses a single flat panel detector and a BB tray. The BBs are arranged in a defined pattern. The shadow of the BBs on the flat panel is analyzed to derive the 3D coordinates of the illumination source, i.e., the dwell position of the brachytherapy source. A kilovoltage x-ray source located 3.3 m away was used to align the center BB with the center pixel on the flat panel detector. For a test plan of 11 dwell positions, with an Ir-192 high dose rate unit, one projection was taken for each dwell point, and locations of the BB shadows were manually identified on the projection images. The 3D coordinates for the 11 dwell positions were reconstructed based on two BBs. The distances between dwell points were compared with the expected values. The average difference was 0.07 cm with a standard deviation of 0.15 cm. With automated BB shadow recognition in the future, this technique possesses the potential of tracking the 3D trajectory and the dwell times of a brachytherapy source in real time, enabling real time source position verification.

  11. Analysis of existing data and specification of an experiment to determine the 252Cf half-life to the required degree of accuracy

    International Nuclear Information System (INIS)

    Lorenz, A.; Kharitonov, I.A.

    1994-02-01

    The methods used and the results obtained in measurements of the 252 Cf half-life are analyzed. In calculating the weighted mean value, additional error components as well as those given by the authors are taken into account. In order to reduce the error in the weighted mean value to less than 0.1%, the need and the requirements for an exact measurement are specified. A half-life of 2.6473±0.0028 years is recommended. (author). 16 refs, 3 tabs

  12. In Plant Measurement and Analysis of Mixtures of Uranium and Plutonium TRU-Waste Using a 252Cf Shuffler Instrument

    International Nuclear Information System (INIS)

    Hurd, J.R.

    1998-01-01

    The active-passive 252 Cf shuffler instrument, installed and certified several years ago in Los Alamos National Laboratory's plutonium facility, has now been calibrated for different matrices to measure Waste Isolation Pilot Plant (WIPP)-destined transuranic (TRU)-waste. Little or no data currently exist for these types of measurements in plant environments where sudden large changes in the neutron background radiation can significantly distort the results. Measurements and analyses of twenty-two 55-gallon drums, consisting of mixtures of varying quantities of uranium and plutonium in mostly noncombustible matrices, have been recently completed at the plutonium facility. The calibration and measurement techniques, including the method used to separate out the plutonium component, will be presented and discussed. Calculations used to adjust for differences in uranium enrichment from that of the calibration standards will be shown. Methods used to determine various sources of both random and systematic error will be indicated. Particular attention will be directed to those problems identified as arising from the plant environment. The results of studies to quantify the aforementioned distortion effects in the data will be presented. Various solution scenarios will be outlined, along with those adopted here

  13. Californium-252

    International Nuclear Information System (INIS)

    1975-01-01

    This meeting constituted the third phase of a project initiated by the Dosimetry Section of the IAEA in 1973. The first step, early in 1973, consisted of the development of a programme for the loan of Cf-252 sources to the Member States in support of education, training and some limited research. To date, 14 institutions in 13 Member States have participated in this loan programme. In August last year, the Agency published an instructional syllabus and laboratory manual authored by Professors Eric J. Hall and Harald H. Rossi of Columbia University (Californium-252 in Teaching and Research, Technical Reports Series No. 159). The appearance of this publication, including guidance on the design and construction of a storage and use facility, was the second phase of this programme aimed at providing some support to potential users in the fields of radiation biology and dosimetry. The objective of the programme's third phase - the convening of an Educational Seminar - was to provide a forum to bring together participants in the Agency's loan programme and experts in various scientific fields. Specifically, the Seminar consisted of a series of expert presentations in spectrometry, activation and prompt gamma analyses, on-stream analysis, dosimetry, health physics, radiology and radiotherapy. (author)

  14. Californium-252 Program Equipment Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Chattin, Fred Rhea [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Kenton [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ezold, Julie G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-12-01

    To successfully continue the 252Cf production and meet the needs of the customers, a comprehensive evaluation of the Building 7920 processing equipment was requested to identify equipment critical to the operational continuity of the program.

  15. Evaluation of TG-43 recommended 2D-anisotropy function for elongated brachytherapy sources

    International Nuclear Information System (INIS)

    Awan, Shahid B.; Meigooni, Ali S.; Mokhberiosgouei, Ramin; Hussain, Manzoor

    2006-01-01

    The original and updated protocols recommended by Task Group 43 from the American Association of Physicists in Medicine (i.e., TG-43 and TG-43U1, respectively), have been introduced to unify brachytherapy source dosimetry around the world. Both of these protocols are based on experiences with sources less than 1.0 cm in length. TG-43U1 recommends that for 103 Pd sources, 2D anisotropy function F(r,θ), should be tabulated at a minimum for radial distances of 0.5, 1.0, 2.0, 3.0, and 5.0 cm. Anisotropy functions defined in these protocols are only valid when the point of calculation does not fall on the active length of the source. However, for elongated brachytherapy sources (active length >1 cm), some of the calculation points with r 103 Pd source at radial distances of 2.5, 3.0, and 4.0 cm were 2.95, 1.74, and 1.19, respectively, with differences up to about a factor of 3. Therefore, the validity of the linear interpolation technique for an elongated brachytherapy source with such a large variation in F(r,θ) needs to be investigated. In this project, application of the TG-43U1 formalism for dose calculation around an elongated RadioCoil trade mark sign 103 Pd brachytherapy source has been investigated. In addition, the linear interpolation techniques as described in TG-43U1 for seed type sources have been evaluated for a 5.0 cm long RadioCoil trade mark sign 103 Pd brachytherapy source. Application of a polynomial fit to F(r,θ) has also been investigated as an alternate approach to the linear interpolation technique. The results of these investigations indicate that the TG-43U1 formalism can be extended for elongated brachytherapy sources, if the two-dimensional (2D) anisotropy function is tabulated at a minimum for radial distances of 0.2, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 cm, L/2, and L/2±0.2 cm. Moreover, with the addition of recommended radial distances for 2D anisotropy functions, the linear interpolation technique more closely replicates

  16. Measurement of uranium and plutonium in solid waste by passive photon or neutron counting and isotopic neutron source interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Crane, T.W.

    1980-03-01

    A summary of the status and applicability of nondestructive assay (NDA) techniques for the measurement of uranium and plutonium in 55-gal barrels of solid waste is reported. The NDA techniques reviewed include passive gamma-ray and x-ray counting with scintillator, solid state, and proportional gas photon detectors, passive neutron counting, and active neutron interrogation with neutron and gamma-ray counting. The active neutron interrogation methods are limited to those employing isotopic neutron sources. Three generic neutron sources (alpha-n, photoneutron, and /sup 252/Cf) are considered. The neutron detectors reviewed for both prompt and delayed fission neutron detection with the above sources include thermal (/sup 3/He, /sup 10/BF/sub 3/) and recoil (/sup 4/He, CH/sub 4/) proportional gas detectors and liquid and plastic scintillator detectors. The instrument found to be best suited for low-level measurements (< 10 nCi/g) is the /sup 252/Cf Shuffler. The measurement technique consists of passive neutron counting followed by cyclic activation using a /sup 252/Cf source and delayed neutron counting with the source withdrawn. It is recommended that a waste assay station composed of a /sup 252/Cf Shuffler, a gamma-ray scanner, and a screening station be tested and evaluated at a nuclear waste site. 34 figures, 15 tables.

  17. Conceptual source design and dosimetric feasibility study for intravascular treatment: a proposal for intensity modulated brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Si Yong; Han, Eun Young; Palta, Jatinder R. [College of Medicine, Florida Univ., Florida (United States); Ha, Sung W. [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2003-06-01

    To propose a conceptual design of a novel source for intensity modulated brachytherapy. The source design incorporates both radioactive and shielding materials (stainless steel or tungsten), to provide an asymmetric dose intensity in the azimuthal direction. The intensity modulated intravascular brachytherapy was performed by combining a series of dwell positions and times, distributed along the azimuthal coordinates. Two simple designs for the beta-emitting sources, with similar physical dimensions to a {sub 90}Sr/Y Novoste Beat-Cath source, were considered in the dosimetric feasibility study. In the first design, the radioactive and materials each occupy half of the cylinder and in the second, the radioactive material occupies only a quarter of the cylinder. The radial and azimuthal dose distributions around each source were calculated using the MCNP Monte Carlo code. The preliminary hypothetical simulation and optimization results demonstrated the 87% difference between the maximum and minimum doses to the lumen wall, due to off-centering of the radiation source, could be reduced to less than 7% by optimizing the azimuthal dwell positions and times of the partially shielded intravascular brachytherapy sources. The novel brachytherapy source design, and conceptual source delivery system, proposed in this study show promising dosimetric characteristics for the realization of intensity modulated brachytherapy in intravascular treatment. Further development of this concept will center on building a delivery system that can precisely control the angular motion of a radiation source in a small-diameter catheter.

  18. Conceptual source design and dosimetric feasibility study for intravascular treatment: a proposal for intensity modulated brachytherapy

    International Nuclear Information System (INIS)

    Kim, Si Yong; Han, Eun Young; Palta, Jatinder R.; Ha, Sung W.

    2003-01-01

    To propose a conceptual design of a novel source for intensity modulated brachytherapy. The source design incorporates both radioactive and shielding materials (stainless steel or tungsten), to provide an asymmetric dose intensity in the azimuthal direction. The intensity modulated intravascular brachytherapy was performed by combining a series of dwell positions and times, distributed along the azimuthal coordinates. Two simple designs for the beta-emitting sources, with similar physical dimensions to a 90 Sr/Y Novoste Beat-Cath source, were considered in the dosimetric feasibility study. In the first design, the radioactive and materials each occupy half of the cylinder and in the second, the radioactive material occupies only a quarter of the cylinder. The radial and azimuthal dose distributions around each source were calculated using the MCNP Monte Carlo code. The preliminary hypothetical simulation and optimization results demonstrated the 87% difference between the maximum and minimum doses to the lumen wall, due to off-centering of the radiation source, could be reduced to less than 7% by optimizing the azimuthal dwell positions and times of the partially shielded intravascular brachytherapy sources. The novel brachytherapy source design, and conceptual source delivery system, proposed in this study show promising dosimetric characteristics for the realization of intensity modulated brachytherapy in intravascular treatment. Further development of this concept will center on building a delivery system that can precisely control the angular motion of a radiation source in a small-diameter catheter

  19. Iridium-192 sources production for brachytherapy use

    International Nuclear Information System (INIS)

    Rostelato, Maria Elisa Chuery Martins

    1997-01-01

    The incidence of cancer increases every year in Brazil and turns out to be one of the most important causes of mortality. Some of the patients are treated with brachytherapy, a form of lesion treatment which is based on the insertion of sources into tumors, in this particular case, activated iridium wires. During this process, the ionizing radiation efficiently destroys the malignant cells. These iridium wires have a nucleus made out of an iridium-platinum alloy 20-30/70-80 of 0,1 mm in diameter either coated by platinum or encased in a platinum tube. The technique consists in irradiating the wire in the reactor neutron flux in order to produce iridium-192. The linear activity goes from 1 mCi/cm to 4 mCi/cm and the basic characteristic, which is required, is the homogeneity of the activation along the wire. It should not present a dispersion exceeding 5% on a wire measuring 50 cm in length, 0.5 mm or 0.3 mm in diameter. Several experiments were carried out in order to define the activation parameters. Wires from different origins were analyzed. It was concluded that United States of America and France wires were found to be perfectly adequate for brachytherapy purposes and have therefore been sent to specialized hospitals and successfully applied to cancer patients. Considering that the major purpose of this work is to make this product more accessible in Brazil, at a cost reflecting the Brazilian reality, the IPEN is promoting the preparation of iridium-192 sources to be used in brachytherapy, on a national level. (author)

  20. Challenges using a 252Cf shuffler instrument in a plant environment to measure mixtures of uranium and plutonium transuranic waste

    International Nuclear Information System (INIS)

    Hurd, J.R.

    1999-01-01

    An active-passive 252 Cf shuffler instrument, installed and certified several years ago at Los Alamos National Laboratory's plutonium facility, has now been calibrated for different matrices to measure Waste Isolation Pilot Plant (WIPP)-destined transuranic (TRU) waste. Little or no data currently exist for these types of measurements in plant environments where sudden large changes in the neutron background radiation can significantly distort the results. Measurements and analyses of twenty-two 55-gallon drums, consisting of mixtures of varying quantities of uranium and plutonium in mostly noncombustible matrices, have been recently completed at the plutonium facility. The calibration and measurement techniques, including the method used to separate out the plutonium component, will be presented and discussed. Calculations used to adjust for differences in uranium enrichment from that of the calibration standards will be shown. Methods used to determine various sources of both random and systematic error will be indicated. Particular attention will be directed to those problems identified as arising from the plant environment. The results of studies to quantify the aforementioned distortion effects in the data will be presented. Various solution scenarios will be outlined, along with those adopted here

  1. Study of fission mechanism with the reactions 230Th, 231Pa, 235U, 237Np(n,f) and 252Cf(fs)

    International Nuclear Information System (INIS)

    Benfoughal, T.

    1983-01-01

    In this work, the different stages of the nuclear fission process have been investigated. The analysis of fission cross-section and fission fragment angular distribution measurements are made using the hypothesis of asymmetrically deformed states. From the correlation between fissioning nucleus excitation energy and fragment total kinetic energy measurement for several fissioning systems, it is shown that the nuclear viscosity is relatively strong during the saddle-point to scission-point transition. The study of the spontaneous fission of 252 Cf shows that the fragment mass and kinetic energy distributions are mainly determinated by the nucleon shell effects and pairing correlations [fr

  2. Algorithms for the process management of sealed source brachytherapy

    International Nuclear Information System (INIS)

    Engler, M.J.; Ulin, K.; Sternick, E.S.

    1996-01-01

    Incidents and misadministrations suggest that brachytherapy may benefit form clarification of the quality management program and other mandates of the US Nuclear Regulatory Commission. To that end, flowcharts of step by step subprocesses were developed and formatted with dedicated software. The overall process was similarly organized in a complex flowchart termed a general process map. Procedural and structural indicators associated with each flowchart and map were critiqued and pre-existing documentation was revised. open-quotes Step-regulation tablesclose quotes were created to refer steps and subprocesses to Nuclear Regulatory Commission rules and recommendations in their sequences of applicability. Brachytherapy algorithms were specified as programmable, recursive processes, including therapeutic dose determination and monitoring doses to the public. These algorithms are embodied in flowcharts and step-regulation tables. A general algorithm is suggested as a template form which other facilities may derive tools to facilitate process management of sealed source brachytherapy. 11 refs., 9 figs., 2 tabs

  3. Novel high resolution 125I brachytherapy source dosimetry using Ge-doped optical fibres

    International Nuclear Information System (INIS)

    Issa, Fatma; Hugtenburg, Richard P.; Nisbet, Andrew; Bradley, David A.

    2013-01-01

    The steep dose gradients close to brachytherapy sources limit the ability to obtain accurate measurements of dose. Here we use a novel high spatial resolution dosimeter to measure dose around a 125 I source and compare against simulations. Ge-doped optical fibres, used as thermoluminescent dosimeters, offer sub-mm spatial resolution, linear response from 10 cGy to >1 kGy and dose-rate independence. For a 125 I brachytherapy seed in a PMMA phantom, doses were obtained for source-dosimeter separations from 0.1 cm up to several cm, supported by EGSnrc/DOSRZznrc Monte Carlo simulations and treatment planning system data. The measurements agree with simulations to within 2.3%±0.3% along the transverse and perpendicular axes and within 3.0%±0.5% for measurements investigating anisotropy in angular dose distribution. Measured and Veriseed™ brachytherapy treatment planning system (TPS) values agreed to within 2.7%±0.5%. Ge-doped optical fibre dosimeters allow detailed dose mapping around brachytherapy sources, not least in situations of high dose gradient. - Highlights: • We evaluate fall-off in dose for distances from an 125 I source of 1 mm to 60 mm. • The TL of optical fibres accommodate high dose gradients and doses that reduce by a factor of 10 3 across the range of separations. • We verify measured values using DOSRZnrc Monte Carlo code simulations and the Variseed™ Treatment Planning System. • Measured radial and angular dose are obtained with ≤3% uncertainty

  4. Development of a semiautomatic cutting machine for the fabrication of 137Cs-brachytherapy sources

    International Nuclear Information System (INIS)

    Avhad, B.G.; Dutta, M.L.; Saxena, S.K.; Dash, A.

    2004-01-01

    Cesium-137 sources are used in brachytherapy for the treatment of gynaecological cancers.The process of source preparation entails the vitrification of radioactive glass, its conversion into glass spheres, subsequent filling of spheres into platinum moulds and cutting of sources into the tubular form of dimension 1.5 mm(OD) x 5 mm(l). The large scale production of these sources demands the remote cutting operations within 4 inch thick lead shielded processing plants. This paper describes the development of a semi-automatic cutting machine, which can be used in the large scale production of 137 Cs brachytherapy sources. (author)

  5. 100 mg 251Cf activation analysis facility at the Savannah River Laboratory

    International Nuclear Information System (INIS)

    MacMurdo, K.W.; Bowman, W.W.

    1975-01-01

    The 252 Cf Activation Analysis Facility at the Savannah River Laboratory (SRL) is used routinely for multielement analyses of a wide variety of solid and liquid samples (e.g., metal alloys, fly ash and other airborne particles, rocks, and aqueous and nonaqueous solutions). An automated absolute activation analysis technique, developed to use neutron transport codes to calculate multienergy group neutron spectra and fluxes, converts counting data directly into elemental concentrations expressed in parts per million. The facility contains four sources of 252 Cf totaling slightly over 100 mg. A pneumatic ''rabbit'' system permits automatic irradiation/decay/counting regimes to be performed unattended on up to 100 samples. Detection sensitivities of less than or equal to 400 ppb natural uranium and less than or equal to 0.5 nCi/g for 239 Pu are observed. Detection limits for over 65 elements have been determined. Over 40 elements are detectable at the one part per million level or less. Overall accuracies of +- 10 percent are observed for most elements. (auth)

  6. Automated box/drum waste assay (252Cf shuffler) through the material access and accountability boundary

    International Nuclear Information System (INIS)

    Horley, E.C.; Bjork, C.W.; Bourret, S.C.; Polk, P.J.; Schneider, C.J.; Studley, R.V.

    1992-01-01

    For the first time, a shuffler waste-assay system has been made a part of material access and accountability boundary (MAAB). A 252 Cf Pass-Thru shuffler integrated with a conveyor handling system, will process box or drum waste across the MAAB. This automated system will significantly reduce personnel operating costs because security forces will not be required at the MAAB during waste transfer. Further, the system eliminates the chance of a mix-up between measured and nonmeasured waste. This Pass-Thru shuffler is to be installed in the Westinghouse Savannah River Company 321M facility to screen waste boxes and drums for 235 U. An automated conveyor will load waste containers into the shuffler, and upon verification, will transfer the containers across the MAAB. Verification will consist of a weight measurement followed by active neutron interrogation. Containers that pass low-level waste criteria will be conveyed to an accumulator section outside the MAAB. If a container fails to meet the waste criteria, it will be rejected and sent back to the load station for manual inspection and repackaging

  7. MR-based source localization for MR-guided HDR brachytherapy

    Science.gov (United States)

    Beld, E.; Moerland, M. A.; Zijlstra, F.; Viergever, M. A.; Lagendijk, J. J. W.; Seevinck, P. R.

    2018-04-01

    For the purpose of MR-guided high-dose-rate (HDR) brachytherapy, a method for real-time localization of an HDR brachytherapy source was developed, which requires high spatial and temporal resolutions. MR-based localization of an HDR source serves two main aims. First, it enables real-time treatment verification by determination of the HDR source positions during treatment. Second, when using a dummy source, MR-based source localization provides an automatic detection of the source dwell positions after catheter insertion, allowing elimination of the catheter reconstruction procedure. Localization of the HDR source was conducted by simulation of the MR artifacts, followed by a phase correlation localization algorithm applied to the MR images and the simulated images, to determine the position of the HDR source in the MR images. To increase the temporal resolution of the MR acquisition, the spatial resolution was decreased, and a subpixel localization operation was introduced. Furthermore, parallel imaging (sensitivity encoding) was applied to further decrease the MR scan time. The localization method was validated by a comparison with CT, and the accuracy and precision were investigated. The results demonstrated that the described method could be used to determine the HDR source position with a high accuracy (0.4–0.6 mm) and a high precision (⩽0.1 mm), at high temporal resolutions (0.15–1.2 s per slice). This would enable real-time treatment verification as well as an automatic detection of the source dwell positions.

  8. Dosimetry experience of 192IR sources used In HDR brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    Daci, Lulzime; Myrku, Rodina Cela

    2013-01-01

    Purpose/Objective: The 192IR Sources are the most commonly used in radiotherapy treatments HDR worldwide. According to international recommendations on quality assurance in HDR brachytherapy, an acceptance test based on the determination of the source strength of any new source shall be carried out before first application to verify the manufacturer’s calibration data. The present paper gives the experimental determination of the source strength for our brachytherapy sources used until now in brachytherapy treatments. Materials/Methods: At Mother Teresa University Hospital we have a cost-effective gynecological brachytherapy unit from Eckert & Ziegler BEBIG named GyneSource® that is a five channel HDR after loader equipped with an 192IR source. The software used is HDR plus™ 2.5 that delivers an optimized treatment plan and makes the process especially fast and we use intracavitary BEBIG applicators. From April 2009 up to December 2012, we have imported nine HDR 192IR Sources. The exchange of the source and acceptance test is done by the physicist of the clinic once the source is imported. The measurements are done with a Well-type ionization chamber HDR1000 Plus and the electrometer used is MAX4000. Only seven sources are compared as we miss the dosimetry data of the first source, and the forth source was not measured and not used because the machine was not working in that time. Results/Conclusions: Eight sources were accepted for clinically use as the measurement were within the tolerance. The source number four with e deviation of -1.92% has been double checked compared with a free in-air measurement with farmer type chamber that gave a deviation to source certificate of 4% that is still inside the tolerance to accept a source for clinical use. The deviations of measured Air Kerma rate to the value of the sources certificates of all our used 192IR sources are less than 2%, which are within the tolerance. The checked value of updated source strength in

  9. Application of fission track detectors to californium-252 neutron dosimetry in tissue near the radiation source

    International Nuclear Information System (INIS)

    Oswald, R.A.; Lanzl, L.H.; Rozenfeld, M.

    1981-01-01

    Fission track detectors were applied to a unique problem in neutron dosimetry. Measurements of neutron doses were required at locations within a tumor of 1 cm diameter implanted on the back of a mouse and surrounded by a square array of four 252 Cf medical sources. Measurements made in a tissue-equivalent mouse phantom showed that the neutron dose rate to the center of the tumor was 2.18 rads mg -1 h -1 +- 8.4%. The spatial variation of neutron dose to the tumor ranged from 1.88 to 2.55 rads mg -1 h -1 . These measurements agree with calculated values of neutron dose to those locations in the phantom. Fission track detectors have been found to be a reliable tool for neutron dosimetry for geometries in which one wishes to know neutron dose values which may vary considerably over distances of 1 cm or less

  10. Application of fission track detectors to californium-252 neutron dosimetry in tissue near the radiation source

    International Nuclear Information System (INIS)

    Oswald, R.A.; Lanzl, L.H.; Rozenfeld, M.

    1981-01-01

    Fission track detectors were applied to a unique problem in neutron dosimetry. Measurements of neutron doses were required at locations within a tumor of 1 cm diameter implanted on the back of a mouse and surrounded by a square array of four 252 Cf medical sources. Measurements made in a tissue-equivalent mouse phantom showed that the neutron dose rate to the center of the tumor was 2.18 rads micrograms-1 h-1 +/- 8.4%. The spatial variation of neutron dose to the tumor ranged from 1.88 to 2.55 rads micrograms-1 h-1. These measurements agree with calculated values of neutron dose to those locations in the phantom. Fission track detectors have been found to be a reliable tool for neutron dosimetry for geometries in which one wishes to know neutron dose values which may vary considerably over distances of 1 cm or less

  11. Three-dimensional tomosynthetic image restoration for brachytherapy source localization

    International Nuclear Information System (INIS)

    Persons, Timothy M.

    2001-01-01

    Tomosynthetic image reconstruction allows for the production of a virtually infinite number of slices from a finite number of projection views of a subject. If the reconstructed image volume is viewed in toto, and the three-dimensional (3D) impulse response is accurately known, then it is possible to solve the inverse problem (deconvolution) using canonical image restoration methods (such as Wiener filtering or solution by conjugate gradient least squares iteration) by extension to three dimensions in either the spatial or the frequency domains. This dissertation presents modified direct and iterative restoration methods for solving the inverse tomosynthetic imaging problem in 3D. The significant blur artifact that is common to tomosynthetic reconstructions is deconvolved by solving for the entire 3D image at once. The 3D impulse response is computed analytically using a fiducial reference schema as realized in a robust, self-calibrating solution to generalized tomosynthesis. 3D modulation transfer function analysis is used to characterize the tomosynthetic resolution of the 3D reconstructions. The relevant clinical application of these methods is 3D imaging for brachytherapy source localization. Conventional localization schemes for brachytherapy implants using orthogonal or stereoscopic projection radiographs suffer from scaling distortions and poor visibility of implanted seeds, resulting in compromised source tracking (reported errors: 2-4 mm) and dosimetric inaccuracy. 3D image reconstruction (using a well-chosen projection sampling scheme) and restoration of a prostate brachytherapy phantom is used for testing. The approaches presented in this work localize source centroids with submillimeter error in two Cartesian dimensions and just over one millimeter error in the third

  12. Evaluation of (101)Rh as a brachytherapy source.

    Science.gov (United States)

    Pakravan, Delaram; Ghorbani, Mahdi; Meigooni, Ali Soleimani

    2015-04-01

    Recently a number of hypothetical sources have been proposed and evaluated for use in brachytherapy. In the present study, a hypothetical (101)Rh source with mean photon energy of 121.5 keV and half-life of 3.3 years, has been evaluated as an alternative to the existing high-dose-rate (HDR) sources. Dosimetric characteristics of this source model have been determined following the recommendation of the Task Group 43 (TG-43) of the American Association of the Physicist in Medicine (AAPM), and the results are compared with the published data for (57)Co source and Flexisource (192)Ir sources with similar geometries. MCNPX Monte Carlo code was used for simulation of the (101)Rh hypothetical HDR source design. Geometric design of this hypothetical source was considered to be similar to that of Flexisource (192)Ir source. Task group No. 43 dosimetric parameters, including air kerma strength per mCi, dose rate constant, radial dose function, and two dimensional (2D) anisotropy functions were calculated for the (101)Rh source through simulations. Air kerma strength per activity and dose rate constant for the hypothetical (101)Rh source were 1.09 ± 0.01 U/mCi and 1.18 ± 0.08 cGy/(h.U), respectively. At distances beyond 1.0 cm in phantom, radial dose function for the hypothetical (101)Rh source is higher than that of (192)Ir. It has also similar 2D anisotropy functions to the Flexisource (192)Ir source. (101)Rh is proposed as an alternative to the existing HDR sources for use in brachytherapy. This source provides medium energy photons, relatively long half-life, higher dose rate constant and radial dose function, and similar 2D anisotropy function to the Flexisource (192)Ir HDR source design. The longer half-life of the source reduces the frequency of the source exchange for the clinical environment.

  13. Evaluation of 101Rh as a brachytherapy source

    Science.gov (United States)

    Ghorbani, Mahdi; Meigooni, Ali Soleimani

    2015-01-01

    Purpose Recently a number of hypothetical sources have been proposed and evaluated for use in brachytherapy. In the present study, a hypothetical 101Rh source with mean photon energy of 121.5 keV and half-life of 3.3 years, has been evaluated as an alternative to the existing high-dose-rate (HDR) sources. Dosimetric characteristics of this source model have been determined following the recommendation of the Task Group 43 (TG-43) of the American Association of the Physicist in Medicine (AAPM), and the results are compared with the published data for 57Co source and Flexisource 192Ir sources with similar geometries. Material and methods MCNPX Monte Carlo code was used for simulation of the 101Rh hypothetical HDR source design. Geometric design of this hypothetical source was considered to be similar to that of Flexisource 192Ir source. Task group No. 43 dosimetric parameters, including air kerma strength per mCi, dose rate constant, radial dose function, and two dimensional (2D) anisotropy functions were calculated for the 101Rh source through simulations. Results Air kerma strength per activity and dose rate constant for the hypothetical 101Rh source were 1.09 ± 0.01 U/mCi and 1.18 ± 0.08 cGy/(h.U), respectively. At distances beyond 1.0 cm in phantom, radial dose function for the hypothetical 101Rh source is higher than that of 192Ir. It has also similar 2D anisotropy functions to the Flexisource 192Ir source. Conclusions 101Rh is proposed as an alternative to the existing HDR sources for use in brachytherapy. This source provides medium energy photons, relatively long half-life, higher dose rate constant and radial dose function, and similar 2D anisotropy function to the Flexisource 192Ir HDR source design. The longer half-life of the source reduces the frequency of the source exchange for the clinical environment. PMID:26034499

  14. Monte Carlo Simulations Validation Study: Vascular Brachytherapy Beta Sources

    International Nuclear Information System (INIS)

    Orion, I.; Koren, K.

    2004-01-01

    During the last decade many versions of angioplasty irradiation treatments have been proposed. The purpose of this unique brachytherapy is to administer a sufficient radiation dose into the vein walls in order to prevent restonosis, a clinical sequel to balloon angioplasty. The most suitable sources for this vascular brachytherapy are the β - emitters such as Re-188, P-32, and Sr-90/Y-90, with a maximum energy range of up to 2.1 MeV [1,2,3]. The radioactive catheters configurations offered for these treatments can be a simple wire [4], a fluid filled balloon or a coated stent. Each source is differently positioned inside the blood vessel, and the emitted electrons ranges therefore vary. Many types of sources and configurations were studied either experimentally or with the use of the Monte Carlo calculation technique, while most of the Monte Carlo simulations were carried out using EGS4 [5] or MCNP [6]. In this study we compared the beta-source absorbed-dose versus radial-distance of two treatment configurations using MCNP and EGS4 simulations. This comparison was aimed to discover the differences between the MCNP and the EGS4 simulation code systems in intermediate energies electron transport

  15. Patient effective dose from endovascular brachytherapy with 192Ir Sources

    International Nuclear Information System (INIS)

    Perna, L.; Bianchi, C.; Novario, R.; Nicolini, G.; Tanzi, F.; Conte, L.

    2002-01-01

    The growing use of endovascular brachytherapy has been accompanied by the publication of a large number of studies in several fields, but few studies on patient dose have been found in the literature. Moreover, these studies were carried out on the basis of Monte Carlo simulation. The aim of the present study was to estimate the effective dose to the patient undergoing endovascular brachytherapy treatment with 192 Ir sources, by means of experimental measurements. Two standard treatments were taken into account: an endovascular brachytherapy of the coronary artery corresponding to the activity x time product of 184 GBq.min and an endovascular brachytherapy of the renal artery (898 GBq.min). Experimental assessment was accomplished by thermoluminescence dosemeters positioned in more than 300 measurement points in a properly adapted Rando phantom. A method has been developed to estimate the mean organ doses for all tissues and organs concerned in order to calculate the effective dose associated with intravascular brachytherapy. The normalised organ doses resulting from coronary treatment were 2.4x10 -2 mSv.GBq -1 .min -1 for lung, 0.9x10 -2 mSv.GBq -1 .min -1 for oesophagus and 0.48x10 -2 mSv.GBq -1 .min -1 for bone marrow. During brachytherapy of the renal artery, the corresponding normalised doses were 4.2x10 -2 mSv.GBq -1 .min -1 for colon, 7.8x10 -2 mSv.GBq -1 .min -1 for stomach and 1.7x10 -2 mSv.GBq -1 .min -1 for liver. Coronary treatment involved an effective dose of 0.046 mSv.GBq -1 .min -1 , whereas the treatment of the renal artery resulted in an effective dose of 0.15 mSv.GBq -1 .min -1 ; there were many similarities with data from former studies. Based on these results it can be concluded that the dose level of patients exposed during brachytherapy treatment is low. (author)

  16. Comparison of radiation shielding requirements for HDR brachytherapy using 169Yb and 192Ir sources

    International Nuclear Information System (INIS)

    Lymperopoulou, G.; Papagiannis, P.; Sakelliou, L.; Georgiou, E.; Hourdakis, C. J.; Baltas, D.

    2006-01-01

    169 Yb has received a renewed focus lately as an alternative to 192 Ir sources for high dose rate (HDR) brachytherapy. Following the results of a recent work by our group which proved 169 Yb to be a good candidate for HDR prostate brachytherapy, this work seeks to quantify the radiation shielding requirements for 169 Yb HDR brachytherapy applications in comparison to the corresponding requirements for the current 192 Ir HDR brachytherapy standard. Monte Carlo simulation (MC) is used to obtain 169 Yb and 192 Ir broad beam transmission data through lead and concrete. Results are fitted to an analytical equation which can be used to readily calculate the barrier thickness required to achieve a given dose rate reduction. Shielding requirements for a HDR brachytherapy treatment room facility are presented as a function of distance, occupancy, dose limit, and facility workload, using analytical calculations for both 169 Yb and 192 Ir HDR sources. The barrier thickness required for 169 Yb is lower than that for 192 Ir by a factor of 4-5 for lead and 1.5-2 for concrete. Regarding 169 Yb HDR brachytherapy applications, the lead shielding requirements do not exceed 15 mm, even in highly conservative case scenarios. This allows for the construction of a lead door in most cases, thus avoiding the construction of a space consuming, specially designed maze. The effects of source structure, attenuation by the patient, and scatter conditions within an actual treatment room on the above-noted findings are also discussed using corresponding MC simulation results

  17. High dose-rate brachytherapy source position quality assurance using radiochromic film

    International Nuclear Information System (INIS)

    Evans, M.D.C.; Devic, S.; Podgorsak, E.B.

    2007-01-01

    Traditionally, radiographic film has been used to verify high-dose-rate brachytherapy source position accuracy by co-registering autoradiographic and diagnostic images of the associated applicator. Filmless PACS-based clinics that do not have access to radiographic film and wet developers may have trouble performing this quality assurance test in a simple and practical manner. We describe an alternative method for quality assurance using radiochromic-type film. In addition to being easy and practical to use, radiochromic film has some advantages in comparison with traditional radiographic film when used for HDR brachytherapy quality assurance

  18. Induction of external abnormalities in offspring of male mice irradiated with 252Cf neutron

    International Nuclear Information System (INIS)

    Kurishita, Akihiro; Ono, Tetsuya; Mori, Yuriko; Okada, Shigefumi; Sawada, Syozo

    1992-01-01

    To assess the genetic effects of fission neutron, the induction of external malformations was studied in F 1 fetuses after F 0 male mice were irradiated. Male mice of the ICR:MCH strain were irradiated with 252 Cf neutron at doses of 0.238, 0.475, 0.95 and 1.9 Gy. They were mated with non-irradiated female mice at 71-120 days after irradiation. Pregnant females were autopsied on day 18 of gestation and their fetuses were examined for deaths and external abnormalities. No increases of pre- and post-implantation losses were noted at any dose. External abnormalities were observed at rates of 1.40% in the 0.238 Gy, 2.23% in the 0.475 Gy, 3.36% in the 0.95 and 3.26% in the 1.9 Gy groups; the rate in the control group was 1.65%. The dose-response curve was linear up to 0.95 Gy, and then flattened out; the induction rate of external abnormalities was 2.7x10 -4 /gamete/cGy based on the linear regression. These results indicated that fission neutron effectively induces external abnormalities in F 1 fetuses after spermatogonial irradiation. (author). 29 refs.; 1 fig.; 2 tabs

  19. Comparison of the hypothetical (57)Co brachytherapy source with the (192)Ir source.

    Science.gov (United States)

    Toossi, Mohammad Taghi Bahreyni; Ghorbani, Mahdi; Rostami, Atefeh; Khosroabadi, Mohsen; Khademi, Sara; Knaup, Courtney

    2016-01-01

    The (57)Co radioisotope has recently been proposed as a hypothetical brachytherapy source due to its high specific activity, appropriate half-life (272 days) and medium energy photons (114.17 keV on average). In this study, Task Group No. 43 dosimetric parameters were calculated and reported for a hypothetical (57)Co source. A hypothetical (57)Co source was simulated in MCNPX, consisting of an active cylinder with 3.5 mm length and 0.6 mm radius encapsulated in a stainless steel capsule. Three photon energies were utilized (136 keV [10.68%], 122 keV [85.60%], 14 keV [9.16%]) for the (57)Co source. Air kerma strength, dose rate constant, radial dose function, anisotropy function, and isodose curves for the source were calculated and compared to the corresponding data for a (192)Ir source. The results are presented as tables and figures. Air kerma strength per 1 mCi activity for the (57)Co source was 0.46 cGyh(-1) cm 2 mCi(-1). The dose rate constant for the (57)Co source was determined to be 1.215 cGyh(-1)U(-1). The radial dose function for the (57)Co source has an increasing trend due to multiple scattering of low energy photons. The anisotropy function for the (57)Co source at various distances from the source is more isotropic than the (192)Ir source. The (57)Co source has advantages over (192)Ir due to its lower energy photons, longer half-life, higher dose rate constant and more isotropic anisotropic function. However, the (192)Ir source has a higher initial air kerma strength and more uniform radial dose function. These properties make (57)Co a suitable source for use in brachytherapy applications.

  20. Measurements of the prompt neutron spectra in 233U, 235U, 239Pu thermal neutron fission in the energy range of 0.01-5 MeV and in 252Cf spontaneous fission in the energy range of 0.01-10 MeV

    International Nuclear Information System (INIS)

    Starostov, B.I.; Semenov, A.F.; Nefedov, V.N.

    1978-01-01

    The measurement results on the prompt neutron spectra in 233 U, 235 U, 239 Pu thermal neutron fission in the energy range of 0.01-5 MeV and in 252 Cf spontaneous fission in the energy range of 0.01-10 MeV are presented. The time-of-flight method was used. The exceeding of the spectra over the Maxwell distributions is observed at E 252 Cf neutron fission spectra. The spectra analysis was performed after normalization of the spectra and corresponding Maxwell distributions for one and the same area. In the range of 0.05-0.22 MeV the yield of 235 U + nsub(t) fission neutrons is approximately 8 and approximately 15 % greater than the yield of 252 Cf and 239 Pu + nsub(t) fission neutrons, respectively. In the range of 0.3-1.2 MeV the yield of 235 U + nsub(t) fission neutrons is 8 % greater than the fission neutron yield in case of 239 Pu + nsub(t) fission. The 235 U + nsub(t) and 233 U + nsub(t) fission neutron spectra do not differ from one another in the 0.05-0.6 MeV range

  1. Neutron sources and its dosimetric characteristics

    International Nuclear Information System (INIS)

    Vega C, H.R.; Manzanares A, E.; Hernandez D, V.M.; Mercado S, G.A.; Gallego D, E.; Lorente F, A.

    2005-01-01

    By means of Monte Carlo methods the spectra of the produced neutrons 252 Cf, 252 Cf/D 2 O, 241 Am Be, 239 Pu Be, 140 La Be, 239 Pu 18 O 2 and 226 Ra Be have been calculated. With the information of the spectrum it was calculated the average energy of the neutrons of each source. By means of the fluence coefficients to dose it was determined, for each one of the studied sources, the fluence factors to dose. The calculated doses were H, H * (10), H p,sIab (10, 0 0 ), E AP and E ISO . During the phase of the calculations the sources were modeled as punctual and their characteristics were determined to 100 cm in the hole. Also, for the case of the sources of 239 Pu Be and 241 Am Be, were carried out calculations modeling the sources with their respective characteristics and the dosimetric properties were determined in a space full with air. The results of this last phase of the calculations were compared with the experimental results obtained for both sources. (Author)

  2. Application of Gafchromic registered film in the dosimetry of an intravascular brachytherapy source

    International Nuclear Information System (INIS)

    Song Haijun; Roa, D. Eduardo; Yue Ning; D'Errico, Francesco; Chen Zhe; Nath, Ravinder

    2006-01-01

    The methodology of brachytherapy source dosimetry with Gafchromic registered MD 55-2 film (ISP Technologies, Inc.) is examined with an emphasis on the nonlinearity of the optical density-dose relation within the dynamic dose range, the radial distance-dependent measurement uncertainty, and the format of data presentation. The specific source chosen for this study was a Checkmate trade mark sign (Cordis Corporation) intravascular brachytherapy system. The two-dimensional dose distribution around the source was characterized by a comprehensive analysis of measurement uncertainties. A comparative analysis of the dosimetric data from the vendor and from the scientific literature showed a substantial consistency of the information available for the Checkmate trade mark sign source. Our two-dimensional dosimetric data for the Checkmate trade mark sign source trains is presented in the form of measured along and away dose tables

  3. Use of polyethylene pellets in the design and construction of a storage safe, a transport vessel and a portable shield for californium-252

    International Nuclear Information System (INIS)

    Sharma, S.

    1986-01-01

    A storage and shielding facility for 300 μg of Californium-252 sources was designed and constructed. Though the safe was in a permanent location, the fact that it consisted of a lead bucket surrounded by polyethylene pellets made it simple, movable and inexpensive. If need be, more quantities of Cf-252 could be added without altering the basic design and sacrificing the radiation protection guidelines. The measured radiation levels from 300 μg of stored Cf-252 in and around the storage vault were lower than the expected dose rates by a factor of 5. The measured radiation levels around the occupied environs of the facility were below the maximum permissible yearly dose of 500mrem for non-occupational workers. A transport vessel was designed and constructed to carry up to 50 μg of Californium-252 sources. It consisted of a standard 55 gallon steel drum on casters containing cylindrical lead shield surrounded by polyethylene pellets. The measured maximum surface dose rates on the drum and at one meter away were within the radiation protection guidelines and were less than the expected dose rates. A portable shield was designed and constructed to protect the body in afterloading operations and handling of the sources. It consisted of polyethylene pellets in an aluminum box and an attached 10 cm thick plexiglass eye shield. The simple design, with the ease of using polyethylene pellets can be extended to construct bedside shields

  4. In vivo dosimetry thermoluminescence dosimeters during brachytherapy with a 370 GBq 192Ir source

    International Nuclear Information System (INIS)

    Cuepers, S.; Piessens, M.; Verbeke, L.; Roelstraete, A.

    1995-01-01

    When using LiF thermoluminescence dosimeters in brachytherapy, we have to take into account the properties of a high dose rate 192 Ir source (energy spectrum ranging form 9 to 885 keV, steep dose gradient in the vicinity of the source) and these of the dosimeters themselves (supralinearity, reproducibility, size). All these characteristics combine into a set of correction factors which have been determined during in phantom measurements. These results have then been used to measure the dose delivered to organs at risk (e.g. rectum, bladder, etc.) during high dose rate brachytherapy with a 370 GBq 192 Ir source for patients with gynaecological tumors

  5. Monte Carlo dosimetry of the IRAsource high dose rate 192Ir brachytherapy source

    International Nuclear Information System (INIS)

    Sarabiasl, Akbar; Ayoobian, Navid; Jabbari, Iraj; Poorbaygi, Hossein; Javanshir, Mohammad Reza

    2016-01-01

    High-dose-rate (HDR) brachytherapy is a common method for cancer treatment in clinical brachytherapy. Because of the different source designs, there is a need for specific dosimetry data set for each HDR model. The purpose of this study is to obtain detailed dose rate distributions in water phantom for a first prototype HDR 192 Ir brachytherapy source model, IRAsource, and compare with the other published works. In this study, Monte Carlo N-particle (MCNP version 4C) code was used to simulate the dose rate distributions around the HDR source. A full set of dosimetry parameters reported by the American Association of Physicists in Medicine Task Group No. 43U1 was evaluated. Also, the absorbed dose rate distributions in water, were obtained in an along-away look-up table. The dose rate constant, Λ, of the IRAsource was evaluated to be equal to 1.112 ± 0.005 cGy h −1 U −1 . The results of dosimetry parameters are presented in tabulated and graphical formats and compared with those reported from other commercially available HDR 192 Ir sources, which are in good agreement. This justifies the use of specific data sets for this new source. The results obtained in this study can be used as input data in the conventional treatment planning systems.

  6. Study of the isomer nuclei produced in the spontaneous fission of {sup 252}Cf; Etude des noyaux isomeriques produits dans la fission spontanee de {sup 252}Cf

    Energy Technology Data Exchange (ETDEWEB)

    Gautherin, C.; Houry, M.; Korten, W.; Le Coz, Y.; Lucas, R.; Thiesen, Ch. [Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee, CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France); Badimon, C.; Barreau, G.; Doan, T.P.; Pedemay, G. [Centre d`Etudes Nucleaires, Bordeaux-1 Univ., 33 Gradignan (France); Belier, G.; Girod, M.; Meot, M.V. [CEA Centre d`Etudes de Bruyeres-le-Chatel, 91 (France); Astier, G.; Meot, V.; Peru, S. [CEA Centre d`Etudes de Bruyeres-le-Chatel, 91 (France); Astier, A.; Ducroux, L.; Meyer, M.; Redon, N. [Inst.de Physique Nucleaire, Lyon-1 Univ., 69 - Villeurbanne (France)

    1997-06-01

    Isomeric states have been studied in fission fragments produced by spontaneous fission of {sup 252}Cf. 34 isomeric nuclei have been identified by using coincidences between {gamma}-rays detected in EUROGAM II and fission fragments detected in photovoltaic cells. Lifetimes from 20 ns up to 2 {mu}s have been measured. Microscopic interpretation of the isomeric levels discovered has been tried by means of the Hartree-Fock-Bogolyubov procedure using Gogny force. It was found that the {sup 152,154,156}Nd nuclei have prolate deformation in their ground state; the rotational band built on this ground state is well reproduced by the calculation. For these nuclei the 2 quasi-particle excited states energies are above 1 MeV in agreement with the experiment. The computation confirms the similitude of the {sup 156}Nd and {sup 158}Sm isomeric states associated to neutron 2 quasi-particles of J{sup {pi}} K{sup {pi}} = 5{sup -} ({nu} 5/2 (642) x {nu} 5/2 (523)) while such similitude does not occur for the isotone nuclei {sup 154}Nd and {sup 156}Sm. The computation predicts a proton 2 quasi-particle excited states of J{sup {pi}} = 5{sup -}, near the isomeric level measured in {sup 156}Sm but not for that of {sup 154}Nd. Concerning the {sup 152}Nd the calculated level density is very near that of the states measured in the 1.6 to 2.3 MeV interval. However, the lack of precise information on spins and parities of the measured levels does make not possible a confrontation with the calculations. An up-graded equipment implying 32 photovoltaic cells instead of 2 cells is to be developed and installed by the EUROGAM 3 refs.

  7. The development and medical applications of a simple facility for partial body in vivo neutron activation analysis using californium-252 sources

    International Nuclear Information System (INIS)

    Boddy, K.

    1978-11-01

    A simple and cheap facility for partial body neutron activation analysis has been designed, based on the use of two 100 μg 252 Cf neutron sources. The results reported show that calcium can be measured in parts of the body such as the tibia with a precision as good as +- 1.6 % for a radiation dose of 2 rem. The uniformity of the thermal neutron flux density is better than +- 3 % over 10 cm. Some applications of this irradiation facility for studies of trace elements, in particular cadmium in liver and aluminium in liver or brain, have also been explored. However, the sensitivity attainable is not yet sufficient for the study of normal levels, but could be of interest in toxicological investigations

  8. Development of an adjoint sensitivity field-based treatment-planning technique for the use of newly designed directional LDR sources in brachytherapy.

    Science.gov (United States)

    Chaswal, V; Thomadsen, B R; Henderson, D L

    2012-02-21

    The development and application of an automated 3D greedy heuristic (GH) optimization algorithm utilizing the adjoint sensitivity fields for treatment planning to assess the advantage of directional interstitial prostate brachytherapy is presented. Directional and isotropic dose kernels generated using Monte Carlo simulations based on Best Industries model 2301 I-125 source are utilized for treatment planning. The newly developed GH algorithm is employed for optimization of the treatment plans for seven interstitial prostate brachytherapy cases using mixed sources (directional brachytherapy) and using only isotropic sources (conventional brachytherapy). All treatment plans resulted in V100 > 98% and D90 > 45 Gy for the target prostate region. For the urethra region, the D10(Ur), D90(Ur) and V150(Ur) and for the rectum region the V100cc, D2cc, D90(Re) and V90(Re) all are reduced significantly when mixed sources brachytherapy is used employing directional sources. The simulations demonstrated that the use of directional sources in the low dose-rate (LDR) brachytherapy of the prostate clearly benefits in sparing the urethra and the rectum sensitive structures from overdose. The time taken for a conventional treatment plan is less than three seconds, while the time taken for a mixed source treatment plan is less than nine seconds, as tested on an Intel Core2 Duo 2.2 GHz processor with 1GB RAM. The new 3D GH algorithm is successful in generating a feasible LDR brachytherapy treatment planning solution with an extra degree of freedom, i.e. directionality in very little time.

  9. Development of an adjoint sensitivity field-based treatment-planning technique for the use of newly designed directional LDR sources in brachytherapy

    Science.gov (United States)

    Chaswal, V.; Thomadsen, B. R.; Henderson, D. L.

    2012-02-01

    The development and application of an automated 3D greedy heuristic (GH) optimization algorithm utilizing the adjoint sensitivity fields for treatment planning to assess the advantage of directional interstitial prostate brachytherapy is presented. Directional and isotropic dose kernels generated using Monte Carlo simulations based on Best Industries model 2301 I-125 source are utilized for treatment planning. The newly developed GH algorithm is employed for optimization of the treatment plans for seven interstitial prostate brachytherapy cases using mixed sources (directional brachytherapy) and using only isotropic sources (conventional brachytherapy). All treatment plans resulted in V100 > 98% and D90 > 45 Gy for the target prostate region. For the urethra region, the D10Ur, D90Ur and V150Ur and for the rectum region the V100cc, D2cc, D90Re and V90Re all are reduced significantly when mixed sources brachytherapy is used employing directional sources. The simulations demonstrated that the use of directional sources in the low dose-rate (LDR) brachytherapy of the prostate clearly benefits in sparing the urethra and the rectum sensitive structures from overdose. The time taken for a conventional treatment plan is less than three seconds, while the time taken for a mixed source treatment plan is less than nine seconds, as tested on an Intel Core2 Duo 2.2 GHz processor with 1GB RAM. The new 3D GH algorithm is successful in generating a feasible LDR brachytherapy treatment planning solution with an extra degree of freedom, i.e. directionality in very little time.

  10. Calibration of photon and beta ray sources used in brachytherapy. Guidelines on standardized procedures at Secondary Standards Dosimetry Laboratories

    International Nuclear Information System (INIS)

    2004-03-01

    It has generally been recognized that international harmonization in radiotherapy dosimetry is essential. Consequently, the IAEA has given much effort to this, for example by publishing a number of reports in the Technical Reports Series (TRS) for external beam dosimetry, most notably TRS-277 and more recently TRS-398. Both of these reports describe in detail the steps to be taken for absorbed dose determination in water and they are often referred to as 'dosimetry protocols'. Similar to TRS-277, it is expected that TRS-398 will be adopted or used as a model by a large number of countries as their national protocol. In 1996, the IAEA established a calibration service for low dose rate (LDR) 137 Cs brachytherapy sources, which is the most widely used source for treatment of gynecological cancer. To further enhance harmonization in brachytherapy dosimetry, the IAEA published in 1999 IAEA-TECDOC-1079 entitled 'Calibration of Brachytherapy Sources. Guidelines on Standardized Procedures for the Calibration of Brachytherapy Sources at Secondary Standard Dosimetry Laboratories (SSDLs) and Hospitals'. The report was well received and was distributed in a large number of copies to the members of the IAEA/WHO network of SSDLs and to medical physicists working with brachytherapy. The present report is an update of the aforementioned TECDOC. Whereas TECDOC-1079 described methods for calibrating brachytherapy sources with photon energies at or above those of 192 Ir, the current report has a wider scope in that it deals with standardization of calibration of all the most commonly used brachytherapy sources, including both photon and beta emitting sources. The latter sources have been in use for a few decades already, but their calibration methods have been unclear. Methods are also described for calibrating sources used in the rapidly growing field of cardiovascular angioplasty. In this application, irradiation of the vessel wall is done in an attempt to prevent restenosis after

  11. The observation of quasi-molecular ions from a tiger snake venom component (Msub(r) 13309) using 252Cf-plasma desorption mass spectrometry

    International Nuclear Information System (INIS)

    Kamensky, I.; Haakansson, P.; Kjellberg, J.; Sundqvist, B.; Fohlman, J.; Peterson, P.A.

    1983-01-01

    A method involving fast heavy-ion bombardment of a solid sample called 252 Cf-plasma desorption mass spectrometry has been used to study a non-enzymatic, non-toxic phospholipase homolog from Australian tiger snake (Notechis scutatus) venom. The protein consists of 119 amino acids in a single polypeptide chain cross-linked by 7 disulfide bridges. The isotopically averaged molecular mass as determined by protein sequence analysis is 13309 atomic mass units (amu). The mass distributions were studied by means of time-of-flight measurements. Quasi-molecular ions associated to the molecule and its dimer were observed. The mass of the quasi-molecular ion corresponding to the molecule was determined to be 13285 +- 25 amu. (Auth.)

  12. Water equivalency evaluation of PRESAGE® dosimeters for dosimetry of Cs-137 and Ir-192 brachytherapy sources

    Science.gov (United States)

    Gorjiara, Tina; Hill, Robin; Kuncic, Zdenka; Baldock, Clive

    2010-11-01

    A major challenge in brachytherapy dosimetry is the measurement of steep dose gradients. This can be achieved with a high spatial resolution three dimensional (3D) dosimeter. PRESAGE® is a polyurethane based dosimeter which is suitable for 3D dosimetry. Since an ideal dosimeter is radiologically water equivalent, we have investigated the relative dose response of three different PRESAGE® formulations, two with a lower chloride and bromide content than original one, for Cs-137 and Ir-192 brachytherapy sources. Doses were calculated using the EGSnrc Monte Carlo package. Our results indicate that PRESAGE® dosimeters are suitable for relative dose measurement of Cs-137 and Ir-192 brachytherapy sources and the lower halogen content PRESAGE® dosimeters are more water equivalent than the original formulation.

  13. Evaluation of hypothetical (153)Gd source for use in brachytherapy.

    Science.gov (United States)

    Ghorbani, Mahdi; Behmadi, Marziyeh

    2016-01-01

    The purpose of this work is to evaluate the dosimetric parameters of a hypothetical (153)Gd source for use in brachytherapy and comparison of the dosimetric parameters with those of (192)Ir and (125)I sources. Dose rate constant, the radial dose function and the two dimensional (2D) anisotropy function data for the hypothetical (153)Gd source were obtained by simulation of the source using MCNPX code and then were compared with the corresponding data reported by Enger et al. A comprehensive comparison between this hypothetical source and a (192)Ir source with similar geometry and a (125)I source was performed as well. Excellent agreement was shown between the results of the two studies. Dose rate constant values for the hypothetical (153)Gd, (192)Ir, (125)I sources are 1.173 cGyh(-1) U(-1), 1.044 cGyh(-1) U(-1), 0.925 cGyh(-1) U(-1), respectively. Radial dose function for the hypothetical (153)Gd source has an increasing trend, while (192)Ir has more uniform and (125)I has more rapidly falling off radial dose functions. 2D anisotropy functions for these three sources indicate that, except at 0.5 cm distance, (192)Ir and (125)I have more isotropic trends as compared to the (153)Gd source. A more uniform radial dose function, and 2D anisotropy functions with more isotropy, a much higher specific activity are advantages of (192)Ir source over (153)Gd. However, a longer half-life of (153)Gd source compared to the other two sources, and lower energy of the source with respect to (192)Ir are advantages of using (153)Gd in brachytherapy versus (192)Ir source.

  14. Radiographic Control of 137-Cs Brachytherapy Sources

    International Nuclear Information System (INIS)

    Bistrovic, M.; Viculin, T.; Jurkovic, S.

    2003-01-01

    1 37C s brachytherapy sources are practical for the intracavitary application due to their relatively long lifetime (T 1/2 = 30 y). On the other hand, due to the relatively low energy (0.66 MeV) of the emitted photons, they are suitable for an efficient radiation protection. The dose distribution around the sources is usually calculated by a specific program. However this program requires the knowledge of the position of sources within the applicator as well as the distribution of activity along them. The only way to learn these data is to make an X-ray picture of applicators and sources superimposed to the autoradiography of every source. It is difficult to achieve satisfactory radiographs with high dose rate sources with standard X-ray film material because autoradiography covers the structure of the radiographic shadow. The problem can be overcome either by applying a high intensity X-ray or gamma beam (originating from a radiotherapeutic machine), or by using photographic material of very low sensitivity, for example photographic paper. Combining both possibilities one can obtain satisfactory images. (author)

  15. In vivo dosimetry thermoluminescence dosimeters during brachytherapy with a 370 GBq {sup 192}Ir source

    Energy Technology Data Exchange (ETDEWEB)

    Cuepers, S; Piessens, M; Verbeke, L; Roelstraete, A [Onze-Lieve-Vrouw Hospitaal, Aalst (Belgium). Dept. of Radiotherapy and Oncology

    1995-12-01

    When using LiF thermoluminescence dosimeters in brachytherapy, we have to take into account the properties of a high dose rate {sup 192}Ir source (energy spectrum ranging form 9 to 885 keV, steep dose gradient in the vicinity of the source) and these of the dosimeters themselves (supralinearity, reproducibility, size). All these characteristics combine into a set of correction factors which have been determined during in phantom measurements. These results have then been used to measure the dose delivered to organs at risk (e.g. rectum, bladder, etc.) during high dose rate brachytherapy with a 370 GBq {sup 192}Ir source for patients with gynaecological tumors.

  16. Testing of ENDF/B cross section data in the Californium-252 neutron benchmark field

    International Nuclear Information System (INIS)

    Mannhart, W.

    1979-01-01

    The fission neutron field of 252 Cf presently represents one of the most well-known neutron benchmark fields. For 13 neutron reactions which are of importance in reactor metrology, measurements of spectrum-averaged cross sections, [sigma], performed in this neutron field were compared with calculated average cross sections. This comparison allows one to draw conclusions as to the quality of different sigma(E) data taken from ENDF/B-IV, from ENDF/B-V, and from recent experiments and used in the calculation of average cross sections. The comparison includes an uncertainty analysis regarding the different uncertainty contributions of [sigma], of sigma(E), and of the spectral distribution of 252 Cf fission neutrons. Additionally, in a few examples, sensitivity studies were carried out. The sensitivity of the spectrum-averaged cross sections to individual characteristics of the sigma(E) data, such as normalization factors or shifts in the energy scale, was investigated. Similarly, the sensitivity of [sigma] to the spectral distribution of 252 Cf was determined. 4 figures, 2 tables

  17. Dose rate constant and energy spectrum of interstitial brachytherapy sources

    International Nuclear Information System (INIS)

    Chen Zhe; Nath, Ravinder

    2001-01-01

    In the past two years, several new manufacturers have begun to market low-energy interstitial brachytherapy seeds containing 125 I and 103 Pd. Parallel to this development, the National Institute of Standards and Technology (NIST) has implemented a modification to the air-kerma strength (S K ) standard for 125 I seeds and has also established an S K standard for 103 Pd seeds. These events have generated a considerable number of investigations on the determination of the dose rate constants (Λ) of interstitial brachytherapy seeds. The aim of this work is to study the general properties underlying the determination of Λ and to develop a simple method for a quick and accurate estimation of Λ. As the dose rate constant of clinical seeds is defined at a fixed reference point, we postulated that Λ may be calculated by treating the seed as an effective point source when the seed's source strength is specified in S K and its source characteristics are specified by the photon energy spectrum measured in air at the reference point. Using a semi-analytic approach, an analytic expression for Λ was derived for point sources with known photon energy spectra. This approach enabled a systematic study of Λ as a function of energy. Using the measured energy spectra, the calculated Λ for 125 I model 6711 and 6702 seeds and for 192 Ir seed agreed with the AAPM recommended values within ±1%. For the 103 Pd model 200 seed, the agreement was 5% with a recently measured value (within the ±7% experimental uncertainty) and was within 1% with the Monte Carlo simulations. The analytic expression for Λ proposed here can be evaluated using a programmable calculator or a simple spreadsheet and it provides an efficient method for checking the measured dose rate constant for any interstitial brachytherapy seed once the energy spectrum of the seed is known

  18. Patient effective dose from endovascular brachytherapy with {sup 192}Ir Sources

    Energy Technology Data Exchange (ETDEWEB)

    Perna, L.; Bianchi, C.; Novario, R.; Nicolini, G.; Tanzi, F.; Conte, L

    2002-07-01

    The growing use of endovascular brachytherapy has been accompanied by the publication of a large number of studies in several fields, but few studies on patient dose have been found in the literature. Moreover, these studies were carried out on the basis of Monte Carlo simulation. The aim of the present study was to estimate the effective dose to the patient undergoing endovascular brachytherapy treatment with {sup 192}Ir sources, by means of experimental measurements. Two standard treatments were taken into account: an endovascular brachytherapy of the coronary artery corresponding to the activity x time product of 184 GBq.min and an endovascular brachytherapy of the renal artery (898 GBq.min). Experimental assessment was accomplished by thermoluminescence dosemeters positioned in more than 300 measurement points in a properly adapted Rando phantom. A method has been developed to estimate the mean organ doses for all tissues and organs concerned in order to calculate the effective dose associated with intravascular brachytherapy. The normalised organ doses resulting from coronary treatment were 2.4x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for lung, 0.9x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for oesophagus and 0.48x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for bone marrow. During brachytherapy of the renal artery, the corresponding normalised doses were 4.2x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for colon, 7.8x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for stomach and 1.7x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for liver. Coronary treatment involved an effective dose of 0.046 mSv.GBq{sup -1}.min{sup -1}, whereas the treatment of the renal artery resulted in an effective dose of 0.15 mSv.GBq{sup -1}.min{sup -1}; there were many similarities with data from former studies. Based on these results it can be concluded that the dose level of patients exposed during brachytherapy treatment is low. (author)

  19. Cs-137 brachytherapy sources calibration with well chamber

    International Nuclear Information System (INIS)

    Brunetto, M.; Sansogne, R.; Arbiser, S.; Duran, M.P.

    2004-01-01

    This work describes the procedures and actions developed for the identification and reference air kerma rate (S k ) verification of Cs-137 sources used in gynecological brachytherapy practices. Following the IAEA TECDOC 1151 recommendations, the first stage consisted in designing the documentation required for the inventory and shipping registry of sources, along with the digital spreadsheets for calculating the decay and S k of the sources at the moment of implantation. As a second stage, the S k of sources was measured, following the low dose rate sources protocol advise, with a Standard Imaging HDR 1000 Plus well chamber calibrated at the University of Wisconsin SSDL. The documentation generated through this procedure allows identify each source clearly and uni-vocally. No significant differences were found between the S k values obtained from the well chamber calibration procedure and those reported by the manufacturer in the corresponding certificates. The highest percent difference found was 2.3%. (author) [es

  20. Modeling a Hypothetical 170Tm Source for Brachytherapy Applications

    International Nuclear Information System (INIS)

    Enger, Shirin A.; D'Amours, Michel; Beaulieu, Luc

    2011-01-01

    Purpose: To perform absorbed dose calculations based on Monte Carlo simulations for a hypothetical 170 Tm source and to investigate the influence of encapsulating material on the energy spectrum of the emitted electrons and photons. Methods: GEANT4 Monte Carlo code version 9.2 patch 2 was used to simulate the decay process of 170 Tm and to calculate the absorbed dose distribution using the GEANT4 Penelope physics models. A hypothetical 170 Tm source based on the Flexisource brachytherapy design with the active core set as a pure thulium cylinder (length 3.5 mm and diameter 0.6 mm) and different cylindrical source encapsulations (length 5 mm and thickness 0.125 mm) constructed of titanium, stainless-steel, gold, or platinum were simulated. The radial dose function for the line source approximation was calculated following the TG-43U1 formalism for the stainless-steel encapsulation. Results: For the titanium and stainless-steel encapsulation, 94% of the total bremsstrahlung is produced inside the core, 4.8 and 5.5% in titanium and stainless-steel capsules, respectively, and less than 1% in water. For the gold capsule, 85% is produced inside the core, 14.2% inside the gold capsule, and a negligible amount ( 170 Tm source is primarily a bremsstrahlung source, with the majority of bremsstrahlung photons being generated in the source core and experiencing little attenuation in the source encapsulation. Electrons are efficiently absorbed by the gold and platinum encapsulations. However, for the stainless-steel capsule (or other lower Z encapsulations) electrons will escape. The dose from these electrons is dominant over the photon dose in the first few millimeter but is not taken into account by current standard treatment planning systems. The total energy spectrum of photons emerging from the source depends on the encapsulation composition and results in mean photon energies well above 100 keV. This is higher than the main gamma-ray energy peak at 84 keV. Based on our

  1. Procedures for brachytherapy sources lost in a radiotherapy department; Protocolo para fontes de braquiterapia extraviadas no ambiente hospitalar

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Adelaide de [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras

    1997-12-31

    Brachytherapy sources are easily lost in a Radiotherapy Department owing to unexpected behaviour of the patient and/or inattention of the people in charge of the sources. This work reports a protocol to be used when brachytherapy sources are lost and it was based on the search of three sealed sources of Cesium 137 with activity of 37 x 10{sup 7} Bq, removed by a patient from a conventional afterloading intra-uterine system (Henscke). (author) 5 refs., 3 figs.; e-mail: dalmeida at biomag.ffclrp.usp.br

  2. Applications of the Italian protocol for the calibration of brachytherapy sources

    International Nuclear Information System (INIS)

    Piermattei, A.; Azario, L.

    1997-01-01

    The Associazione Italiana di Fisica Biomedica (AIFB; Italian Association of Biomedical Physics) has adopted the Italian protocol for the calibration of brachytherapy sources. The AIFB protocol allows measurements of the reference air kerma rate, dK/dt r , within 1.7% (1σ). To measure dK/dt r the AIFB protocol has identified a direct and an indirect procedure. The direct procedure is based on the use of spherical or cylindrical ionization chambers as local reference dosimeters positioned along the transverse bisector axis of the source. Once the source is specified by a dK/dt r value, this can be used to calibrate a field instrument, such as a well-type ionization chamber, for further source calibrations by means of an indirect procedure. This paper reports the results obtained by the Physics Laboratory of the Universita Cattolica del S Cuore (PL-UCSC), in terms of dK/dt r calibration of five types of source, 169 Yb, 192 Ir and 137 Cs. The role of the dK/dt r determination for a brachytherapy source has been underlined when a new source such as the 169 Yb seed model X1267 has been proposed for clinical use. The dK/dt r values for 137 Cs spherical sources differed by 5% from the vendor's mean value. The five types of source calibrated in terms of dK/dt r were used to obtain the calibration factor, N K r source , of an HDR-1000 well-type ionization chamber. (author)

  3. Evaluation of neutron sources for ISAGE-in-situ-NAA for a future lunar mission

    International Nuclear Information System (INIS)

    Li, X.; Breitkreutz, H.; Burfeindt, J.; Bernhardt, H.-G.; Trieloff, M.; Hopp, J.; Jessberger, E.K.; Schwarz, W.H.; Hofmann, P.; Hiesinger, H.

    2011-01-01

    For a future Moon landing, a concept for an in-situ NAA involving age determination using the 40 Ar- 39 Ar method is developed. A neutron source 252 Cf is chosen for sample irradiation on the Moon. A special sample-in-source irradiation geometry is designed to provide a homogeneous distribution of neutron flux at the irradiation position. Using reflector, the neutron flux is likely to increase by almost 200%. Sample age of 1 Ga could be determined. Elemental analysis using INAA is discussed. - Highlights: → We developed a concept for an in-situ age determination on the Moon. → 252 Cf is chosen as the neutron source for the 40 Ar- 39 Ar-method. → A sample-in-source geometry is designed to provide homogeneous neutron flux. → Determination of U, Th, K and Ir using NAA on the Moon is possible.

  4. Treatment of bulky stage IB and IIB cervical cancers with outpatient neutron brachytherapy, external pelvic radiation and extrafascial hysterectomy

    International Nuclear Information System (INIS)

    Van Nagell, J.R.; Maruyama, Y.; Yoneda, J.; Donaldson, E.S.; Hanson, M.B.; Gallion, H.H.; Powell, D.E.; Kryscio, R.J.

    1986-01-01

    From January, 1977, to December, 1982, twenty-nine patients with bulky (>4 cms diameter) Stage IB or IIB cervical cancer were treated at the University of Kentucky Medical Center by a combination of out-patient neutron brachytherapy (Cf-252) and external pelvic radiation followed by extrafascial hysterectomy. Residual tumor was present in the hysterectomy specimens of 25 per cent. Complications during and following radiation therapy and surgery were minimal and included vaginal stenosis, proctitis, and hemorrhagic cystitis. The mean duration of hospitalization for surgery in these patients was 6.6 days (range 5-15 days) and postoperative morbidity was low. No patient required blood transfusion. Four patients developed urinary tract infections and two had superficial wound separations. Following treatment, patients were seen at monthly intervals for one year, every three months for two years, and every six months thereafter. No patient has been lost to follow-up. Two patients (7 per cent) developed tumor recurrence and have died of disease (1 of distant metastases; 1 local). The remaining 27 patients (93 per cent) are alive and well with no evidence of disease 24-89 months (mean 48 months) after therapy. No radiogenic fistulae or bowel obstruction were observed. These preliminary results suggest that the combination of outpatient neutron brachytherapy, external pelvic radiation, and extrafascial hysterectomy for patients with Stage IB and IIB cervical cancer is well tolerated. Complications associated with this treatment regimen have been minimal, and the recurrence rate is low. The duration of intracavitary neutron brachytherapy was short, and outpatient therapy was well received by patients

  5. Material-specific Conversion Factors for Different Solid Phantoms Used in the Dosimetry of Different Brachytherapy Sources

    Directory of Open Access Journals (Sweden)

    Sedigheh Sina

    2015-07-01

    Full Text Available Introduction Based on Task Group No. 43 (TG-43U1 recommendations, water phantom is proposed as a reference phantom for the dosimetry of brachytherapy sources. The experimental determination of TG-43 parameters is usually performed in water-equivalent solid phantoms. The purpose of this study was to determine the conversion factors for equalizing solid phantoms to water. Materials and Methods TG-43 parameters of low- and high-energy brachytherapy sources (i.e., Pd-103, I-125 and Cs-137 were obtained in different phantoms, using Monte Carlo simulations. The brachytherapy sources were simulated at the center of different phantoms including water, solid water, poly(methyl methacrylate, polystyrene and polyethylene. Dosimetric parameters such as dose rate constant, radial dose function and anisotropy function of each source were compared in different phantoms. Then, conversion factors were obtained to make phantom parameters equivalent to those of water. Results Polynomial coefficients of conversion factors were obtained for all sources to quantitatively compare g(r values in different phantom materials and the radial dose function in water. Conclusion Polynomial coefficients of conversion factors were obtained for all sources to quantitatively compare g(r values in different phantom materials and the radial dose function in water.

  6. The D-D Neutron Generator as an Alternative to Am(Li) Isotopic Neutron Source in the Active Well Coincidence Counter

    Energy Technology Data Exchange (ETDEWEB)

    McElroy, Robert Dennis [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cleveland, Steven L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-03-01

    The 235U mass assay of bulk uranium items, such as oxide canisters, fuel pellets, and fuel assemblies, is not achievable by traditional gamma-ray assay techniques due to the limited penetration of the item by the characteristic 235U gamma rays. Instead, fast neutron interrogation methods such as active neutron coincidence counting must be used. For international safeguards applications, the most commonly used active neutron systems, the Active Well Coincidence Counter (AWCC), Uranium Neutron Collar (UNCL) and 252Cf Shuffler, rely on fast neutron interrogation using an isotopic neutron source [i.e., 252Cf or Am(Li)] to achieve better measurement accuracies than are possible using gamma-ray techniques for high-mass, high-density items. However, the Am(Li) sources required for the AWCC and UNCL systems are no longer manufactured, and newly produced systems rely on limited supplies of sources salvaged from disused instruments. The 252Cf shuffler systems rely on the use of high-output 252Cf sources, which while still available have become extremely costly for use in routine operations and require replacement every five to seven years. Lack of a suitable alternative neutron interrogation source would leave a potentially significant gap in the safeguarding of uranium processing facilities. In this work, we made use of Oak Ridge National Laboratory’s (ORNL’s) Large Volume Active Well Coincidence Counter (LV-AWCC) and a commercially available deuterium-deuterium (D-D) neutron generator to examine the potential of the D-D neutron generator as an alternative to the isotopic sources. We present the performance of the LV-AWCC with D-D generator for the assay of 235U based on the results of Monte Carlo N-Particle (MCNP) simulations and measurements of depleted uranium (DU), low enriched uranium (LEU), and highly enriched uranium (HEU) items.

  7. Moderator design studies for a new neutron reference source based on the D–T fusion reaction

    International Nuclear Information System (INIS)

    Mozhayev, Andrey V.; Piper, Roman K.; Rathbone, Bruce A.; McDonald, Joseph C.

    2016-01-01

    The radioactive isotope Californium-252 ( 252 Cf) is relied upon internationally as a neutron calibration source for ionizing radiation dosimetry because of its high specific activity. The source may be placed within a heavy-water (D 2 O) moderating sphere to produce a softened spectrum representative of neutron fields common to commercial nuclear power plant environments, among others. Due to termination of the U.S. Department of Energy loan/lease program in 2012, the expense of obtaining 252 Cf sources has undergone a significant increase, rendering high output sources largely unattainable. On the other hand, the use of neutron generators in research and industry applications has increased dramatically in recent years. Neutron generators based on deuteriumtritium (D–T) fusion reaction provide high neutron fluence rates and, therefore, could possibly be used as a replacement for 252 Cf. To be viable, the 14 MeV D–T output spectrum must be significantly moderated to approximate common workplace environments. This paper presents the results of an effort to select appropriate moderating materials and design a configuration to reshape the primary neutron field toward a spectrum approaching that from a nuclear power plant workplace. A series of Monte-Carlo (MCNP) simulations of single layer high- and low-Z materials are used to identify initial candidate moderators. Candidates are refined through a similar series of simulations involving combinations of 2–5 different materials. The simulated energy distribution using these candidate moderators are rated in comparison to a target spectrum. Other properties, such as fluence preservation and/or enhancement, prompt gamma production and other characteristics are also considered. - Highlights: • D–T generator neutron calibration field replacement for D 2 O-moderated 252 Cf. • Determination of representative nuclear power plant workplace neutron spectrum. • Simulations to assess moderating materials to soften 14

  8. Implementation of the Fissile Mass Flow Monitor Source Verification and Confirmation

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, Taner [ORNL; March-Leuba, Jose A [ORNL; Powell, Danny H [ORNL; Nelson, Dennis [Sandia National Laboratories (SNL); Radev, Radoslav [Lawrence Livermore National Laboratory (LLNL)

    2007-12-01

    This report presents the verification procedure for neutron sources installed in U.S. Department of Energy equipment used to measure fissile material flow. The Fissile Mass Flow Monitor (FMFM) equipment determines the {sup 235}U fissile mass flow of UF{sub 6} gas streams by using {sup 252}Cf neutron sources for fission activation of the UF{sub 6} gas and by measuring the fission products in the flow. The {sup 252}Cf sources in each FMFM are typically replaced every 2 to 3 years due to their relatively short half-life ({approx} 2.65 years). During installation of the new FMFM sources, the source identity and neutronic characteristics provided by the manufacturer are verified with the following equipment: (1) a remote-control video television (RCTV) camera monitoring system is used to confirm the source identity, and (2) a neutron detection system (NDS) is used for source-strength confirmation. Use of the RCTV and NDS permits remote monitoring of the source replacement process and eliminates unnecessary radiation exposure. The RCTV, NDS, and the confirmation process are described in detail in this report.

  9. Implementation of the Fissile Mass Flow Monitor Source Verification and Confirmation

    International Nuclear Information System (INIS)

    Uckan, Taner; March-Leuba, Jose A.; Powell, Danny H.; Nelson, Dennis; Radev, Radoslav

    2007-01-01

    This report presents the verification procedure for neutron sources installed in U.S. Department of Energy equipment used to measure fissile material flow. The Fissile Mass Flow Monitor (FMFM) equipment determines the 235 U fissile mass flow of UF 6 gas streams by using 252 Cf neutron sources for fission activation of the UF 6 gas and by measuring the fission products in the flow. The 252 Cf sources in each FMFM are typically replaced every 2 to 3 years due to their relatively short half-life (∼ 2.65 years). During installation of the new FMFM sources, the source identity and neutronic characteristics provided by the manufacturer are verified with the following equipment: (1) a remote-control video television (RCTV) camera monitoring system is used to confirm the source identity, and (2) a neutron detection system (NDS) is used for source-strength confirmation. Use of the RCTV and NDS permits remote monitoring of the source replacement process and eliminates unnecessary radiation exposure. The RCTV, NDS, and the confirmation process are described in detail in this report.

  10. Measurement of the average number of prompt neutrons emitted per fission of 235U relative to 252Cf for the energy region 500 eV to 10 MeV

    International Nuclear Information System (INIS)

    Gwin, R.; Spencer, R.R.; Ingle, R.W.; Todd, J.H.; Weaver, H.

    1980-01-01

    The average number of prompt neutrons emitted per fission ν/sub p/-bar(E), was measured for 235 U relative to ν/sub p/-bar for the spontaneous fission of 252 Cf over the neutron energy range from 500 eV to 10 MeV. The samples of 235 U and 252 Cf were contained in fission chambers located in the center of a large liquid scintillator. Fission neutrons were detected by the large liquid scintillator. The present values of ν/sub p/-bar(E) for 235 U are about 0.8% larger than those measured by Boldeman. In earlier work with the present system, it was noted that Boldeman's value of ν/sub p/-bar(E) for thermal energy neutrons was about 0.8% lower than obtained at ORELA. It is suggested that the thickness of the fission foil used in Boldeman's experiment may cause some of the discrepancy between his and the present values of ν/sub p/-bar(E). For the energy region up to 700 keV, the present values of ν/sub p/-bar(E) for 235 U agree, within the uncertainty, with those given in ENDF/B-V. Above 1 MeV the present results for ν/sub p/-bar(E) range about the ENDF/B-V values with differences up to 1.3%. 6 figures, 1 table

  11. Neutron spectra and dosimetric features of isotopic neutron sources: a review

    International Nuclear Information System (INIS)

    Vega C, H. R.; Martinez O, S. A.

    2015-10-01

    A convenient way to produce neutrons is the isotopic neutron source, where the production is through (α, n), (γ, n), and spontaneous fission reactions. Isotopic neutron sources are small, easy to handle, and have a relative low cost. On the other hand the neutron yield is small and mostly of them produces neutrons with a wide energy distribution. In this work, a review is carried out about the the main features of 24 NaBe, 24 NaD 2 O, 116 InBe, 140 LaBe, 238 PuLi, 239 PuBe, 241 AmB, 241 AmBe, 241 AmF, 241 AmLi, 242 CmBe, 210 PoBe, 226 RaBe, 252 Cf and 252 Cf/D 2 O isotopic neutron source. Also, using Monte Carlo methods, the neutron spectra in 31 energy groups, the neutron mean energy; the Ambient dose equivalent, the Personal dose equivalent and the Effective dose were calculated for these isotopic neutron sources. (Author)

  12. Resolving the brachytherapy challenges with government funded hospital.

    Science.gov (United States)

    Nikam, D S; Jagtap, A S; Vinothraj, R

    2016-01-01

    The objective of this study is to rationalize the feasibility and cost-effectiveness of high dose rate (HDR) cobalt 60 (Co-60) source versus 192-Iridium (192-Ir) source brachytherapy in government funded hospitals and treatment interruption gap because of exchange of sources. A retrospective study of gynecological cancer patients, treated by radiotherapy with curative intent between April 2005 and September 2012 was conducted. We analyzed the total number of patients treated for external beam radiotherapy (EBRT) and brachytherapy (Intracavitary brachytherapy or cylindrical vaginal source). The dates for 192-Ir sources installation and the last date and first date of brachytherapy procedure before and after source installation respectively were also analyzed and calculated the gap in days for brachytherapy interruptions. The study was analyzed the records of 2005 to September 2012 year where eight 192-Ir sources were installed. The mean gap between treatment interruptions was 123.12 days (range 1-647 days). The Institutional incidence of gynecological cancer where radiotherapy was treatment modality (except ovary) is 34.9 percent. Around 52.25 percent of patients who received EBRT at this institute were referred to outside hospital for brachytherapy because of unavailability of Iridium source. The cost for 5 year duration for single cobalt source is approximately 20-22 lakhs while for 15 Iridium sources is approximately 52-53 lakhs. The combined HDR Co-60 brachytherapy and EBRT provide a useful modality in the treatment of gynecological cancer where radiotherapy is indicated, the treatment interruption because of source exchange is longer and can be minimized by using cobalt source as it is cost-effective and has 5 year working life. Thus, Co-60 source for brachytherapy is a feasible option for government funded hospitals in developing countries.

  13. 5He, 7He, and 8Li (E*=2.26 MeV) intermediate ternary particles in the spontaneous fission of 252Cf

    International Nuclear Information System (INIS)

    Kopatch, Yu.N.; Mutterer, M.; Schwalm, D.; Thirolf, P.; Goennenwein, F.

    2002-01-01

    The neutron-unstable odd-N isotopes 5 He, 7 He, and 8 Li (in its excited state of E*=2.26 MeV) were measured to show up as short-lived (τ≅10 -21 -10 -20 s) intermediate light charged particles (LCPs) in ternary fission of 252 Cf. For the study a high-efficiency angular correlation measurement between neutrons, LCPs, and main fission fragments has been performed. The evidence for the ternary 5 He and 7 He particles (lifetimes: 1x10 -21 s, and 4x10 -21 s, respectively) was disclosed from the measured angular distributions of their decay neutrons focused by the emission in flight towards the direction of motion of 4 He and 6 He ternary particles. Similarly, neutrons observed to be peaked around Li-particle motion could be attributed to the decay of the second excited state at E*=2.26 MeV (lifetime: 2x10 -20 s) of 8 Li. The fractional yields of the intermediate 5 He and 7 He ternary fission modes relative to the 'true' ternary 4 He and 6 He modes, respectively, were determined to be 0.21(5) for both cases. The mean energy of the 4 He residues resulting from the 5 He decay was determined to be 12.4(3) MeV, compared to 15.7(2) MeV for all ternary α particles registered, and to 16.4(3) MeV for the true ternary α particles. The mean energy of the 6 He residues from the 7 He decay is 11.0(15) MeV, compared to 12.3(5) MeV for all ternary 6 He particles. The population of 8 Li* was deduced to be 0.06(2) relative to Li ternary fission, and 0.33(20) relative to the yield of particle stable 8 Li. The perspective of using the observed intermediate LCPs for probing the ternary scission configuration in 252 Cf fission with the aid of trajectory calculations is briefly discussed

  14. 5He, 7He and 8Li (E=2.26 MeV) intermediate ternary particles in the spontaneous fission of 252Cf

    International Nuclear Information System (INIS)

    Kopatch, Yu. N.; Goennenwein, F.

    2002-02-01

    The neutron-unstable odd-N isotopes 5 He, 7 He and 8 Li (in its excited state of E * = 2.26 MeV) were measured to show up as short-lived intermediate light-charged-particles (LCP) in ternary fission of 252 Cf. For the study a high-efficiency angular correlation measurement between neutrons, LCPs and main fission fragments has been performed. The evidence for the ternary 5 He and 7 He particles (lifetimes: 1 x 10 -21 s, and 4 x 10 -21 s, respectively) was disclosed from the measured angular distributions of their decay neutrons focused by the emission in flight towards the direction of motion of 4 He and 6 He ternary particles. Similarly, neutrons observed to be peaked around Li-particle motion could be attributed to the decay of the second excited state at E * = 2.26 MeV (lifetime: 2 x 10 -20 s) of 8 Li. The fractional yields of the intermediate 5 He and 7 He ternary fission modes relative to the ''true'' ternary 4 He and 6 He modes, respectively, were determined to be 0.21(5) for both cases. The mean energy of the 4 He residues resulting from the 5 He decay was determined to be 12.4(3) MeV, compared to 15.7(2) MeV for all ternary α-particles registered, and to 16.4(3) MeV for the true ternary α-particles. The mean energy of the 6 He residues from the 7 He decay is 11.0(15) MeV, compared to 12.3(5) MeV for all ternary 6 He particles. The population of 8 Li * was deduced to be 0.06(2) relative to Li ternary fission, and 0.33(20) relative to the yield of particle stable 8 Li. The perspective of using the observed intermediate LCPs for probing the ternary scission configuration in 252 Cf fission with the aid of trajectory calculations is briefly discussed. (orig.)

  15. Microdosimetric evaluation of relative biological effectiveness for 103PD, 125I, 241AM, and 192IR brachytherapy sources

    International Nuclear Information System (INIS)

    Wuu, C.S.; Kliauga, P.; Zaider, M.; Amols, H.I.

    1996-01-01

    Purpose: To determine the microdosimetric-derived relative biological effectiveness (RBE) of 103 Pd, 125 I, 241 Am, and 192 Ir brachytherapy sources at low doses and/or low dose rates. Methods and Materials: The Theory of Dual Radiation Action can be used to predict expected RBE values based on the spatial distribution of energy deposition at microscopic levels from these sources. Single-event lineal energy spectra for these isotopes have been obtained both experimentally and theoretically. A grid-defined wall-less proportional counter was used to measure the lineal energy distributions. Unlike conventional Rossi proportional counters, the counter used in these measurements has a conducting nylon fiber as the central collecting anode and has no metal parts. Thus, the Z-dependence of the photoelectric effect is eliminated as a source of measurement error. Single-event spectra for these brachytherapy sources have been also calculated by: (a) the Monte Carlo code MCNP to generate the electron slowing down spectrum, (b) transport of monoenergetic electron tracks, event by event, with our Monte Carlo code DELTA, (c) using the concept of associated volume to obtain the lineal energy distribution f(y) for each monoenergetic electron, and (d) obtaining the composite lineal energy spectrum for a given brachytherapy source based on the electron spectrum calculated at step (a). Results: Relative to 60 Co, the RBE values obtained from this study are: 2.3 for 103 Pd, 2.1 for 125 I, 2.1 for 241 Am, and 1.3 for 192 Ir. Conclusions: These values are consistent with available data from in vitro cell survival experiments. We suggest that, at least for these brachytherapy sources, microdosimetry may be used as a credible alternative to time-consuming (and often uncertain) radiobiological experiments to obtain information on radition quality and make reliable predictions of RBE in low dose rate brachytherapy

  16. Biomedical neutron research at the Californium User Facility for neutron science

    International Nuclear Information System (INIS)

    Martin, R.C.; Byrne, T.E.; Miller, L.F.

    1997-01-01

    The Californium User Facility for Neutron Science has been established at Oak Ridge National Laboratory (ORNL). The Californium User Facility (CUF) is a part of the larger Californium Facility, which fabricates and stores compact 252 Cf neutron sources for worldwide distribution. The CUF can provide a cost-effective option for research with 252 Cf sources. Three projects at the CUF that demonstrate the versatility of 252 Cf for biological and biomedical neutron-based research are described: future establishment of a 252 Cf-based neutron activation analysis system, ongoing work to produce miniature high-intensity, remotely afterloaded 252 Cf sources for tumor therapy, and a recent experiment that irradiated living human lung cancer cells impregnated with experimental boron compounds to test their effectiveness for boron neutron capture therapy

  17. Dosimetry of iridium-192 sources used in brachytherapy

    International Nuclear Information System (INIS)

    Henn, Keli Cristina

    1999-09-01

    The use of high dose rate brachytherapy (HDR) has been increasing in recent years, due to several advantages relative to conventional low dose rate brachytherapy, such as: shorter treatment times, the ability to fractionate treatment (and thus perform many treatments on an outpatient basis) and reduced worker exposures. Most HDR equipment uses small, high activity 192 Ir sources, which are introduced into the patient using a remote system. The dose distribution around these sources is strongly dependent on the size and shape of the active volume and on the encapsulation of the source. The objective of this work is to compare two methods of calibrating sources of 192 Ir, mamely, measurements in air with an ionization thimble chamber or with a well-type ionization chamber. In addition, we measured the anisotropy of the sources and made comparisons with values supplied by the manufacturer, since this factor is taken into account in the planning system algorithm when dose distributions are calculated. The dose was also evaluated at points of clinical interest (i.e. in the rectum and bladder) and compared to values obtained with the Nucletron PLATO-BPS planning system. The use of lead for rectal protection was evaluated in a cylindrical applicator, aiming the further development of a gynecological applicator. The results of the calibration of seven sources showed that the uncertainty in the calibration in a 'jig' system is smaller than 1%, compared to the value supplied by the source manufacturer. The differences between the results obtained with the well-type ionization camera and the 'jig' system were around 2%. The anisotropy showed good agreement with the values supplied by the manufacturer. The results show that the anisotropy factors, in air and water, are approximately constant and equal to 1.0, for angles between 70 deg and 150 deg. For angles smaller than 70 deg the anisotropy factor in water is larger than in air. Results are also presented for 180 deg, which

  18. The comparison of four neutron sources for Prompt Gamma Neutron Activation Analysis (PGNAA) in vivo detections of boron.

    Science.gov (United States)

    Fantidis, J G; Nicolaou, G E; Potolias, C; Vordos, N; Bandekas, D V

    A Prompt Gamma Ray Neutron Activation Analysis (PGNAA) system, incorporating an isotopic neutron source has been simulated using the MCNPX Monte Carlo code. In order to improve the signal to noise ratio different collimators and a filter were placed between the neutron source and the object. The effect of the positioning of the neutron beam and the detector relative to the object has been studied. In this work the optimisation procedure is demonstrated for boron. Monte Carlo calculations were carried out to compare the performance of the proposed PGNAA system using four different neutron sources ( 241 Am/Be, 252 Cf, 241 Am/B, and DT neutron generator). Among the different systems the 252 Cf neutron based PGNAA system has the best performance.

  19. Assessment of the risks associated with Iodine-125 handling production sources for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Daiane C.B.; Rostelato, Maria Elisa C.; Vicente, Roberto; Zeituni, Carlos A.; Tiezzi, Rodrigo; Costa, Osvaldo L.; Souza, Carla D.; Peleias Junior, Fernando S.; Rodrigues, Bruna T.; Souza, Anderson S.; Batista, Talita Q.; Melo, Emerson R.; Camargo, Anderson R., E-mail: dcsouza@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Karam Junior, Dib, E-mail: dib.karam@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil)

    2015-07-01

    In Brazil, prostate cancer is the second most frequent disease, with an estimated 68,800 new cases in 2013. This type of cancer can be treated with brachytherapy, which uses sealed sources of Iodine-125 implanted permanently in the prostate. These sources are currently imported at a high cost, making public treatment in large scale impractical. To reduce costs and to meet domestic demand, the laboratory for production of brachytherapy sources at the Nuclear and Energy Research Institute (IPEN) is currently nationalizing the production of this radioisotope. Iodine is quite volatile making the handling of its radioactive isotopes potentially dangerous. The aim of this paper is to evaluate the risks to which workers are exposed during the production and handling of the sources. The research method consisted initially of a literature review on the toxicity of iodine, intake limits, related physical risks, handling of accidents, generation of radioactive wastes, etc. The results allowed for establishing safety and radioprotection policies in order to ensure efficient and safe production in all stages and the implementation of good laboratory practices. (author)

  20. Assessment of the risks associated with Iodine-125 handling production sources for brachytherapy

    International Nuclear Information System (INIS)

    Souza, Daiane C.B.; Rostelato, Maria Elisa C.; Vicente, Roberto; Zeituni, Carlos A.; Tiezzi, Rodrigo; Costa, Osvaldo L.; Souza, Carla D.; Peleias Junior, Fernando S.; Rodrigues, Bruna T.; Souza, Anderson S.; Batista, Talita Q.; Melo, Emerson R.; Camargo, Anderson R.; Karam Junior, Dib

    2015-01-01

    In Brazil, prostate cancer is the second most frequent disease, with an estimated 68,800 new cases in 2013. This type of cancer can be treated with brachytherapy, which uses sealed sources of Iodine-125 implanted permanently in the prostate. These sources are currently imported at a high cost, making public treatment in large scale impractical. To reduce costs and to meet domestic demand, the laboratory for production of brachytherapy sources at the Nuclear and Energy Research Institute (IPEN) is currently nationalizing the production of this radioisotope. Iodine is quite volatile making the handling of its radioactive isotopes potentially dangerous. The aim of this paper is to evaluate the risks to which workers are exposed during the production and handling of the sources. The research method consisted initially of a literature review on the toxicity of iodine, intake limits, related physical risks, handling of accidents, generation of radioactive wastes, etc. The results allowed for establishing safety and radioprotection policies in order to ensure efficient and safe production in all stages and the implementation of good laboratory practices. (author)

  1. Monte Carlo Simulation of stepping source in afterloading intracavitary brachytherapy for GZP6 unit

    International Nuclear Information System (INIS)

    Toossi, M.T.B.; Abdollahi, M.; Ghorbani, M.

    2010-01-01

    Full text: Stepping source in brachytherapy systems is used to treat a target lesion longer than the effective treatment length of the source. Dose calculation accuracy plays a vital role in the outcome of brachytherapy treatment. In this study, the stepping source (channel 6) of GZP6 brachytherapy unit was simulated by Monte Carlo simulation and matrix shift method. The stepping source of GZP6 was simulated by Monte Carlo MCNPX code. The Mesh tally (type I) was employed for absorbed dose calculation in a cylindrical water phantom. 5 x 108 photon histories were scored and a 0.2% statistical uncertainty was obtained by Monte Carlo calculations. Dose distributions were obtained by our matrix shift method for esophageal cancer tumor lengths of 8 and 10 cm. Isodose curves produced by simulation and TPS were superimposed to estimate the differences. Results Comparison of Monte Carlo and TPS dose distributions show that in longitudinal direction (source movement direction) Monte Carlo and TPS dose distributions are comparable. [n transverse direction, the dose differences of 7 and 5% were observed for esophageal tumor lengths of 8 and 10 cm respectively. Conclusions Although, the results show that the maximum difference between Monte Carlo and TPS calculations is about 7%, but considering that the certified activity is given with ± I 0%, uncertainty, then an error of the order of 20% for Monte Carlo calculation would be reasonable. It can be suggested that accuracy of the dose distribution produced by TPS is acceptable for clinical applications. (author)

  2. Evaluation of neutron sources for ISAGE-in-situ-NAA for a future lunar mission

    Energy Technology Data Exchange (ETDEWEB)

    Li, X., E-mail: xiaosong.li@frm2.tum.de [Forschungs-Neutronenquelle Heinz Maier-Leibnitz, FRM II, Technische Universitaet Muenchen, Lichtenbergstr. 1, D-85747 Garching (Germany); Breitkreutz, H. [Forschungs-Neutronenquelle Heinz Maier-Leibnitz, FRM II, Technische Universitaet Muenchen, Lichtenbergstr. 1, D-85747 Garching (Germany); Burfeindt, J.; Bernhardt, H.-G. [Kayser-Threde GmbH, Wolfratshauser Str. 48, D-81379 Muenchen (Germany); Trieloff, M.; Hopp, J. [Institut fuer Geowissenschaften, Ruprecht-Karls-Universitaet Heidelberg, D-69120 Heidelberg (Germany); Jessberger, E.K. [Institut fuer Planetologie, Westfaelische Wilhelms-Universitaet Muenster, D-48149 Muenster (Germany); Schwarz, W.H. [Institut fuer Geowissenschaften, Ruprecht-Karls-Universitaet Heidelberg, D-69120 Heidelberg (Germany); Hofmann, P. [Kayser-Threde GmbH, Wolfratshauser Str. 48, D-81379 Muenchen (Germany); Hiesinger, H. [Institut fuer Planetologie, Westfaelische Wilhelms-Universitaet Muenster, D-48149 Muenster (Germany)

    2011-11-15

    For a future Moon landing, a concept for an in-situ NAA involving age determination using the {sup 40}Ar-{sup 39}Ar method is developed. A neutron source {sup 252}Cf is chosen for sample irradiation on the Moon. A special sample-in-source irradiation geometry is designed to provide a homogeneous distribution of neutron flux at the irradiation position. Using reflector, the neutron flux is likely to increase by almost 200%. Sample age of 1 Ga could be determined. Elemental analysis using INAA is discussed. - Highlights: > We developed a concept for an in-situ age determination on the Moon. > {sup 252}Cf is chosen as the neutron source for the {sup 40}Ar-{sup 39}Ar-method. > A sample-in-source geometry is designed to provide homogeneous neutron flux. > Determination of U, Th, K and Ir using NAA on the Moon is possible.

  3. Calibration of photon and beta ray sources used in brachytherapy. Guidelines on standardized procedures at Secondary Standards Dosimetry Laboratories (SSDLs) and hospitals

    International Nuclear Information System (INIS)

    2002-03-01

    It has generally been recognized that international harmonization in radiotherapy dosimetry is essential. Consequently, the IAEA has given much effort to this, for example by publishing a number of reports in the Technical Reports Series (TRS) for external beam dosimetry, most notably TRS-277 and more recently TRS-398. Both of these reports describe in detail the steps to be taken for absorbed dose determination in water and they are often referred to as 'dosimetry protocols'. Similar to TRS-277, it is expected that TRS-398 will be adopted or used as a model by a large number of countries as their national protocol. In 1996, the IAEA established a calibration service for low dose rate (LDR) 137 Cs brachytherapy sources, which is the most widely used source for treatment of gynecological cancer. To further enhance harmonization in brachytherapy dosimetry, the IAEA published in 1999 IAEA-TECDOC-1079 entitled 'Calibration of Brachytherapy Sources. Guidelines on Standardized Procedures for the Calibration of Brachytherapy Sources at Secondary Standard Dosimetry Laboratories (SSDLs) and Hospitals'. The report was well received and was distributed in a large number of copies to the members of the IAEA/WHO network of SSDLs and to medical physicists working with brachytherapy. The present report is an update of the aforementioned TECDOC. Whereas TECDOC-1079 described methods for calibrating brachytherapy sources with photon energies at or above those of 192 Ir, the current report has a wider scope in that it deals with standardization of calibration of all the most commonly used brachytherapy sources, including both photon and beta emitting sources. The latter sources have been in use for a few decades already, but their calibration methods have been unclear. Methods are also described for calibrating sources used in the rapidly growing field of cardiovascular angioplasty. In this application, irradiation of the vessel wall is done in an attempt to prevent restenosis after

  4. A Comparison of the Dosimetric Parameters of Cs-137 Brachytherapy Source in Different Tissues with Water Using Monte Carlo Simulation

    Directory of Open Access Journals (Sweden)

    Sedigheh Sina

    2012-03-01

    Full Text Available Introduction After the publication of Task Group number 43 dose calculation formalism by the American Association of Physicists in Medicine (AAPM, this method has been known as the most common dose calculation method in brachytherapy treatment planning. In this formalism, the water phantom is introduced as the reference dosimetry phantom, while the attenuation coefficient of the sources in the water phantom is different from that of different tissues. The purpose of this study is to investigate the effects of the phantom materials on the TG-43 dosimetery parameters of the Cs-137 brachytherapy source using MCNP4C Monte Carlo code. Materials and Methods In this research, the Cs-137 (Model Selectron brachytherapy source was simulated in different phantoms (bone, soft tissue, muscle, fat, and the inhomogeneous phantoms of water/bone of volume 27000 cm3 using MCNP4C Monte Carlo code. *F8 tally was used to obtain the dose in a fine cubical lattice. Then the TG-43 dosimetry parameters of the brachytherapy source were obtained in water phantom and compared with those of different phantoms. Results The percentage difference between the radial dose function g(r of bone and the g(r of water phantom, at a distance of 10 cm from the source center is 20%, while such differences are 1.7%, 1.6% and 1.1% for soft tissue, muscle, and fat, respectively. The largest difference of the dose rate constant of phantoms with those of water is 4.52% for the bone phantom, while the differences for soft tissue, muscle, and fat are 1.18%, 1.27%, and 0.18%, respectively. The 2D anisotropy function of the Cs-137 source for different tissues is identical to that of water. Conclusion The results of the simulations have shown that dose calculation in water phantom would introduce errors in the dose calculation around brachytherapy sources. Therefore, it is suggested that the correction factors of different tissues be applied after dose calculation in water phantoms, in order to

  5. Study of the shielding for spontaneous fission sources of Californium-252

    International Nuclear Information System (INIS)

    Davila R, I.

    1991-06-01

    A shielding study is made to attenuate, until maximum permissible levels, the neutrons radiation and photons emitted by spontaneous fission coming from a source of Californium-252. The compound package by a database (Library DLC-23) and the ANISNW code is used, in it version for personal computer. (Author)

  6. Biomedical neutron research at the Californium User Facility for Neutron Science

    International Nuclear Information System (INIS)

    Martin, R.C.; Byrne, T.E.; Miller, L.F.

    1998-01-01

    The Californium User Facility for Neutron Science has been established at Oak Ridge National Laboratory (ORNL). The Californium User Facility (CUF) is a part of the larger Californium Facility, which fabricates and stores compact 252 Cf neutron sources for worldwide distribution. The CUF can provide a cost-effective option for research with 252 Cf sources. Three projects at the CUF that demonstrate the versatility of 252 Cf for biological and biomedical neutron-based research are described: future establishment of a 252 Cf-based neutron activation analysis system, ongoing work to produce miniature high-intensity, remotely afterloaded 252 Cf sources for tumor therapy, and a recent experiment that irradiated living human lung cancer cells impregnated with experimental boron compounds to test their effectiveness for boron neutron capture therapy. (author)

  7. Air core detectors for Cerenkov-free scintillation dosimetry of brachytherapy β-sources.

    Science.gov (United States)

    Eichmann, Marion; Thomann, Benedikt

    2017-09-01

    Plastic scintillation detectors are used for dosimetry in small radiation fields with high dose gradients, e.g., provided by β-emitting sources like 106 Ru/ 106 Rh eye plaques. A drawback is a background signal caused by Cerenkov radiation generated by electrons passing the optical fibers (light guides) of this dosimetry system. Common approaches to correct for the Cerenkov signal are influenced by uncertainties resulting from detector positioning and calibration procedures. A different approach to avoid any correction procedure is to suppress the Cerenkov signal by replacing the solid core optical fiber with an air core light guide, previously shown for external beam therapy. In this study, the air core concept is modified and applied to the requirements of dosimetry in brachytherapy, proving its usability for measuring water energy doses in small radiation fields. Three air core detectors with different air core lengths are constructed and their performance in dosimetry for brachytherapy β-sources is compared with a standard two-fiber system, which uses a second fiber for Cerenkov correction. The detector systems are calibrated with a 90 Sr/ 90 Y secondary standard and tested for their angular dependence as well as their performance in depth dose measurements of 106 Ru/ 106 Rh sources. The signal loss relative to the standard detector increases with increasing air core length to a maximum value of 58.3%. At the same time, however, the percentage amount of Cerenkov light in the total signal is reduced from at least 12.1% to a value below 1.1%. There is a linear correlation between induced dose and measured signal current. The air core detectors determine the dose rates for 106 Ru/ 106 Rh sources without any form of correction for the Cerenkov signal. The air core detectors show advantages over the standard two-fiber system especially when measuring in radiation fields with high dose gradients. They can be used as simple one-fiber systems and allow for an almost

  8. Measurement of the energy spectrum of {sup 252}Cf fission fragments using nuclear track detectors and digital image processing

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa, G.; Golzarri, J. I. [UNAM, Instituto de Fisica, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Castano, V. M. [UNAM, Centro de Fisica Aplicada y Tecnologia Avanzada, Boulevard Juriquilla 3001, Santiago de Queretaro, 76230 Queretaro (Mexico); Gaso, I. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Mena, M.; Segovia, N. [UNAM, Instituto de Geofisica, Circuito de la Investigacion Cientifica, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2010-02-15

    The energy spectrum of {sup 252}Cf fission fragments was measured using nuclear track detectors and digital image analysis system. The detection material was fused silica glass. The detectors were chemically etched in an 8% HF solution. After experimenting with various etching time, it was found that the best resolution of the track diameter distribution was obtained after 30 minutes of etching. Both Gaussian and Lorentzian curves were fit to the track diameter distribution histograms and used to determine the basic parameters of the distribution of the light (N{sub L}) and heavy (N{sub H}) formed peaks and the minimum of the central valley (N{sub V}). Advantages of the method presented here include the fully-automated analysis process, the low cost of the nuclear track detectors and the simplicity of the nuclear track method. The distribution resolution obtained by this method is comparable with the resolution obtained by electronic analysis devices. The descriptive variables calculated were very close to those obtained by other methods based on the use of semiconductor detectors. (Author)

  9. Coulomb effects in isobaric cold fission from reactions 233U(nth,f), 235U(nth,f),239Pu(nth,f) and 252Cf(sf)

    International Nuclear Information System (INIS)

    Montoya, Modesto

    2013-01-01

    The Coulomb effect hypothesis, formerly used to interpret fluctuations in the curve of maximal total kinetic energy as a function of light fragment mass in reactions 233 U(n th ,f), 235 U(n th ,f) and 239 Pu(n th ,f), is confirmed in high kinetic energy as well as in low excitation energy windows, respectively. Data from reactions 233 U(n th ,f), 235 U(n th ,f), 239 Pu(n th ,f) and 252 Cf(sf) show that, between two isobaric fragmentations with similar Q-values, the more asymmetric charge split reaches the higher value of total kinetic energy. Moreover, in isobaric charge splits with different Q-values, similar preference for asymmetrical fragmentations is observed in low excitation energy windows. (author).

  10. Monte Carlo simulation of MOSFET dosimeter for brachytherapy sources

    International Nuclear Information System (INIS)

    Suchitra, G.; Bharanidharan, G.; Manigandan, D.; Aruna, P.; Ganesan, S.; Subbaiah, K.V.

    2008-01-01

    In vivo patient dose verification is considered to be an important part of quality assurance in radiotherapy, as there may be uncertainty between the prescribed dose and the dose actually delivered to the patients. A dose estimator method was used to calculate the dose in the extremely thin sensitive volume. This work shows the response of MOSFET detector for various brachytherapy sources at various experimental condition and the results were compared with the earlier published values. The details of computations and the results are discussed

  11. Sensitivity of the 252Cf(sf neutron observables to the FREYA input yield functions Y(A, Z, TKE

    Directory of Open Access Journals (Sweden)

    Randrup Jørgen

    2017-01-01

    Full Text Available Within the framework of the fission event generator FREYA, we are studying the sensitivity of various neutron observables to the yield distribution Y (A,Z,TKE used as input to the code. Concentrating on spontaneous fission of 252Cf, we have sampled a large number of different input yield functions based on χ2 fits to the experimental data on Y (A and Y (TKE|A. For each of these input yield distributions, we then use FREYA to generate a large sample of complete fission events from which we extract a variety of neutron observables, including the multiplicity distribution, the associated correlation coefficients, and its factorial moments, the dependence of the mean neutron multiplicity on the total fragment kinetic energy TKE and on the fragment mass number A, the neutron energy spectrum, and the two-neutron angular correlation function. In this way, we can determine the variation of these observables resulting from the uncertainties in the experimental mesurements. The imposition of a constraint on the resulting mean neutron multiplicity reduces the variation of the calculated neutron observables and provides a means for shrinking the uncertainties associated with the measured data.

  12. Sensitivity of the 252Cf(sf) neutron observables to the FREYA input yield functions Y(A, Z, TKE)

    Science.gov (United States)

    Randrup, Jørgen; Talou, Patrick; Vogt, Ramona

    2017-09-01

    Within the framework of the fission event generator FREYA, we are studying the sensitivity of various neutron observables to the yield distribution Y (A,Z,TKE) used as input to the code. Concentrating on spontaneous fission of 252Cf, we have sampled a large number of different input yield functions based on χ2 fits to the experimental data on Y (A) and Y (TKE|A). For each of these input yield distributions, we then use FREYA to generate a large sample of complete fission events from which we extract a variety of neutron observables, including the multiplicity distribution, the associated correlation coefficients, and its factorial moments, the dependence of the mean neutron multiplicity on the total fragment kinetic energy TKE and on the fragment mass number A, the neutron energy spectrum, and the two-neutron angular correlation function. In this way, we can determine the variation of these observables resulting from the uncertainties in the experimental mesurements. The imposition of a constraint on the resulting mean neutron multiplicity reduces the variation of the calculated neutron observables and provides a means for shrinking the uncertainties associated with the measured data.

  13. Brachytherapy dosimetry parameters calculated for a 131Cs source

    International Nuclear Information System (INIS)

    Rivard, Mark J.

    2007-01-01

    A comprehensive analysis of the IsoRay Medical model CS-1 Rev2 131 Cs brachytherapy source was performed. Dose distributions were simulated using Monte Carlo methods (MCNP5) in liquid water, Solid TM , and Virtual Water TM spherical phantoms. From these results, the in-water brachytherapy dosimetry parameters have been determined, and were compared with those of Murphy et al. [Med. Phys. 31, 1529-1538 (2004)] using measurements and simulations. Our results suggest that calculations obtained using erroneous cross-section libraries should be discarded as recommended by the 2004 AAPM TG-43U1 report. Our MC Λ value of 1.046±0.019 cGy h -1 U -1 is within 1.3% of that measured by Chen et al. [Med. Phys. 32, 3279-3285 (2005)] using TLDs and the calculated results of Wittman and Fisher [Med. Phys. 34, 49-54 (2007)] using MCNP5. Using the discretized energy approach of Rivard [Appl. Radiat. Isot. 55, 775-782 (2001)] to ascertain the impact of individual 131 Cs photons on radial dose function and anisotropy functions, there was virtual equivalence of results for 29.461≤E γ ≤34.419 keV and for a mono-energetic 30.384 keV photon source. Comparisons of radial dose function and 2D anisotropy function data are also included, and an analysis of material composition and cross-section libraries was performed

  14. Determination of the tissue inhomogeneity correction in high dose rate Brachytherapy for Iridium-192 source

    Directory of Open Access Journals (Sweden)

    Barlanka Ravikumar

    2012-01-01

    Full Text Available In Brachytherapy treatment planning, the effects of tissue heterogeneities are commonly neglected due to lack of accurate, general and fast three-dimensional (3D dose-computational algorithms. In performing dose calculations, it is assumed that the tumor and surrounding tissues constitute a uniform, homogeneous medium equivalent to water. In the recent past, three-dimensional computed tomography (3D-CT based treatment planning for Brachytherapy applications has been popularly adopted. However, most of the current commercially available planning systems do not provide the heterogeneity corrections for Brachytherapy dosimetry. In the present study, we have measured and quantified the impact of inhomogeneity caused by different tissues with a 0.015 cc ion chamber. Measurements were carried out in wax phantom which was employed to measure the heterogeneity. Iridium-192 (192 Ir source from high dose rate (HDR Brachytherapy machine was used as the radiation source. The reduction of dose due to tissue inhomogeneity was measured as the ratio of dose measured with different types of inhomogeneity (bone, spleen, liver, muscle and lung to dose measured with homogeneous medium for different distances. It was observed that different tissues attenuate differently, with bone tissue showing maximum attenuation value and lung tissue resulting minimum value and rest of the tissues giving values lying in between those of bone and lung. It was also found that inhomogeneity at short distance is considerably more than that at larger distances.

  15. Spectroscopic output of {sup 125}I and {sup 103}Pd low dose rate brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Usher-Moga, Jacqueline; Beach, Stephen M.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin--Madison, Madison, Wisconsin 53705 (United States); Global Physics Solutions, St. Joseph, Michigan 49085 (United States); Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

    2009-01-15

    The spectroscopic output of low dose rate (LDR) brachytherapy sources is dependent on the physical design and construction of the source. Characterization of the emitted photons from 12 {sup 125}I and 3 {sup 103}Pd LDR brachytherapy source models is presented. Photon spectra, both along the transverse bisector and at several polar angles, were measured in air with a high-purity reverse electrode germanium (REGe) detector. Measured spectra were corrected to in vacuo conditions via Monte Carlo and analytical methods. The tabulated and plotted spectroscopic data provide a more complete understanding of each source model's output characteristics than can be obtained with other measurement techniques. The variation in fluorescence yield of the {sup 125}I sources containing silver caused greater differences in the emitted spectra and average energies among these seed models than was observed for the {sup 103}Pd sources or the {sup 125}I sources that do not contain silver. Angular spectroscopic data further highlighted the effects of source construction unique to each model, as well as the asymmetric output of many seeds. These data demonstrate the need for the incorporation of such physically measured output characteristics in the Monte Carlo modeling process.

  16. Neutron spectra and dosimetric features of isotopic neutron sources: a review

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas, Zac. (Mexico); Martinez O, S. A., E-mail: fermineutron@yahoo.com [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, Av. Central del Norte 39-115, 150003 Tunja, Boyaca (Colombia)

    2015-10-15

    A convenient way to produce neutrons is the isotopic neutron source, where the production is through (α, n), (γ, n), and spontaneous fission reactions. Isotopic neutron sources are small, easy to handle, and have a relative low cost. On the other hand the neutron yield is small and mostly of them produces neutrons with a wide energy distribution. In this work, a review is carried out about the the main features of {sup 24}NaBe, {sup 24}NaD{sub 2}O, {sup 116}InBe, {sup 140}LaBe, {sup 238}PuLi, {sup 239}PuBe, {sup 241}AmB, {sup 241}AmBe, {sup 241}AmF, {sup 241}AmLi, {sup 242}CmBe, {sup 210}PoBe, {sup 226}RaBe, {sup 252}Cf and {sup 252}Cf/D{sub 2}O isotopic neutron source. Also, using Monte Carlo methods, the neutron spectra in 31 energy groups, the neutron mean energy; the Ambient dose equivalent, the Personal dose equivalent and the Effective dose were calculated for these isotopic neutron sources. (Author)

  17. About brachytherapy for the handling of cancer

    International Nuclear Information System (INIS)

    Campos, Tarcisio P.R.; Silva, Nilton O.; Damaso, Renato S.; Costa, Helder R.; Borges, Paulo H.R.; Mendes, Bruno M.

    2000-01-01

    The technique of brachytherapy is argued in this article. The 'hardware' and 'necessary software' for the handling are summarily presented. Being the macro-dosimetry an important stage in the radiation therapy procedure, a simplified method of doses evaluation in conventional brachytherapy is presented. In an illustrative form, isodoses of a three-dimensional distribution of linear sources are drawn on a digitalized X-ray picture, exemplifying the handling of breast brachytherapy by sources of iridium

  18. Comparison of 60Cobalt and 192Iridium sources in high dose rate afterloading brachytherapy

    International Nuclear Information System (INIS)

    Richter, J.; Baier, K.; Flentje, M.

    2008-01-01

    Purpose: 60 Co sources with dimensions identical to those of 192 Ir have recently been made available in clinical brachytherapy. A longer half time reduces demands on logistics and quality assurance and perhaps costs. Material and Methods: Comparison of the physical properties of 60 Co and 192 Ir with regard to brachytherapy. Results: Required activities for the same air kerma rate are lower by a factor of 2.8 for 60 Co. Differential absorption in tissues of different densities can be neglected. Monte Carlo calculations demonstrate that integral dose due to radial dose fall off is higher for 192 Ir in comparison to 60 Co within the first 22 cm from the source (normalization at 1 cm). At larger distances this relationship is reversed. Conclusion: Clinical examples for intracavitary and interstitial applications however, show practically identical dose distributions in the treatment volume. (orig.)

  19. Sensitivity studies in Monte Carlo treatment planning for neutron brachytherapy of cervical cancer : role of boron augmentation

    International Nuclear Information System (INIS)

    Ralston, A.; Wallace, S.A.; Allen, B.J.

    1996-01-01

    Cervical cancer is the most common malignancy of women in the world and in the third world often presents in an advanced state. While photo radiation therapy is an established form of treatment, neutron brachytherapy with Cf-252 has proven to give superior local control in advanced cases without serious complications. This advantage arises from the reduction in radio-resistance, ascribed to hypoxia in bulky tumours, which occurs with high LET radiation. A further improvement is being sought by dose augmentation with boron neutron capture therapy. The Los Alamos Monte Carlo Neutron Photon radiation transport code MCNP is being used to investigate the effects of fat, muscle, bone and voids in the fast and thermal dose distributions. Whereas the fast neutron dose determines normal tissue tolerance, the boron neutron capture dose rate is determined by the thermal flux distribution. The neutron spectrum is sensitive to changes in hydrogen density, as occurs with muscle, fat and bone. The implications of this sensitivity are examined to determine whether detailed individual Monte Carlo calculations are required for patient clinical treatment plans. (author)

  20. Monte Carlo modeling of 60 Co HDR brachytherapy source in water and in different solid water phantom materials

    Directory of Open Access Journals (Sweden)

    Sahoo S

    2010-01-01

    Full Text Available The reference medium for brachytherapy dose measurements is water. Accuracy of dose measurements of brachytherapy sources is critically dependent on precise measurement of the source-detector distance. A solid phantom can be precisely machined and hence source-detector distances can be accurately determined. In the present study, four different solid phantom materials such as polymethylmethacrylate (PMMA, polystyrene, Solid Water, and RW1 are modeled using the Monte Carlo methods to investigate the influence of phantom material on dose rate distributions of the new model of BEBIG 60 Co brachytherapy source. The calculated dose rate constant is 1.086 ± 0.06% cGy h−1 U−1 for water, PMMA, polystyrene, Solid Water, and RW1. The investigation suggests that the phantom materials RW1 and Solid Water represent water-equivalent up to 20 cm from the source. PMMA and polystyrene are water-equivalent up to 10 cm and 15 cm from the source, respectively, as the differences in the dose data obtained in these phantom materials are not significantly different from the corresponding data obtained in liquid water phantom. At a radial distance of 20 cm from the source, polystyrene overestimates the dose by 3% and PMMA underestimates it by about 8% when compared to the corresponding data obtained in water phantom.

  1. Radiation sources and methods for producing them

    International Nuclear Information System (INIS)

    Malson, H.A.; Moyer, S.E.; Honious, H.B.; Janzow, E.F.

    1979-01-01

    The radiation sources contain a substrate with an electrically conducting, non-radioactive metal surface, a layer of a metal isotope of the scandium group as well as a percentage of non-radioactive binding metal being coated on the surface by means of an electroplating method. Besides examples for β sources ( 147 Pm), γ sources ( 241 Am), and neutron sources ( 252 Cf) there is described an α-radiation source ( 241 Am, 244 Cu, 238 Pu) for smoke detectors. There are given extensive tables and a bibliography. (DG) [de

  2. Brachytherapy

    Science.gov (United States)

    ... the use of a type of energy, called ionizing radiation, to kill cancer cells and shrink tumors. External ... In all cases of brachytherapy, the source of radiation is encapsulated ... non-radioactive metallic capsule. This prevents the radioactive materials ...

  3. Standardization of the calibration of brachytherapy sources at the IAEA dosimetry laboratory

    International Nuclear Information System (INIS)

    Shanta, A.; Andreo, P.

    1996-01-01

    A new service to SSDLs has been initiated at the IAEA Dosimetry Laboratory for providing calibrations of well-type ionisation chambers, used in brachytherapy applications, which are traceable to the International Measurement System. Considering that the most common radionuclide used in the developing countries is 137 Cs, two such sources of the type used for gynaecological intracavitary applications have been purchased by the Agency and calibrated at the National Institute of Standards and Technology (NIST), USA. These 137 Cs reference sources together with a well-type ionization chamber constitute the IAEA brachytherapy dosimetry standard. Based on the recommendations by a group of experts, a method has been developed for transferring calibrations to SSDLs which is described in this paper. The method is based on the acquisition by the SSDLs of sources and equipment similar to those at the IAEA. The well-type chamber is to be calibrated at the IAEA Dosimetry Laboratory, and this will be used at the SSDL to calibrate its own reference sources. These sources can in turn by used to calibrate well-type chambers from hospital users and to calibrate other type of sources by performing measurements in air. In order to standardize the procedures for the two methods and to provide guidance to the SSDLs, measurements have been carried out at the IAEA Dosimetry Laboratory. The reproducibility of the two type of measurements has been found to be better than 0.5%, and the uncertainty of calibrations estimated to be less than 1.5% (one standard deviation). (author). 8 refs, 8 figs, 2 tabs

  4. Determination of the intrinsic energy dependence of LiF:Mg,Ti thermoluminescent dosimeters for 125I and 103Pd brachytherapy sources relative to 60Co.

    Science.gov (United States)

    Reed, J L; Rasmussen, B E; Davis, S D; Micka, J A; Culberson, W S; DeWerd, L A

    2014-12-01

    To determine the intrinsic energy dependence of LiF:Mg,Ti thermoluminescent dosimeters (TLD-100) for (125)I and (103)Pd brachytherapy sources relative to (60)Co. LiF:Mg,Ti TLDs were irradiated with low-energy brachytherapy sources and with a (60)Co teletherapy source. The brachytherapy sources measured were the Best 2301 (125)I seed, the OncoSeed 6711 (125)I seed, and the Best 2335 (103)Pd seed. The TLD light output per measured air-kerma strength was determined for the brachytherapy source irradiations, and the TLD light output per air kerma was determined for the (60)Co irradiations. Monte Carlo (MC) simulations were used to calculate the dose-to-TLD rate per air-kerma strength for the brachytherapy source irradiations and the dose to TLD per air kerma for the (60)Co irradiations. The measured and MC-calculated results for all irradiations were used to determine the TLD intrinsic energy dependence for (125)I and (103)Pd relative to (60)Co. The relative TLD intrinsic energy dependences (relative to (60)Co) and associated uncertainties (k = 1) were determined to be 0.883 ± 1.3%, 0.870 ± 1.4%, and 0.871 ± 1.5% for the Best 2301 seed, OncoSeed 6711 seed, and Best 2335 seed, respectively. The intrinsic energy dependence of TLD-100 is dependent on photon energy, exhibiting changes of 13%-15% for (125)I and (103)Pd sources relative to (60)Co. TLD measurements of absolute dose around (125)I and (103)Pd brachytherapy sources should explicitly account for the relative TLD intrinsic energy dependence in order to improve dosimetric accuracy.

  5. Determination of the intrinsic energy dependence of LiF:Mg,Ti thermoluminescent dosimeters for 125I and 103Pd brachytherapy sources relative to 60Co

    International Nuclear Information System (INIS)

    Reed, J. L.; Micka, J. A.; Culberson, W. S.; DeWerd, L. A.; Rasmussen, B. E.; Davis, S. D.

    2014-01-01

    Purpose: To determine the intrinsic energy dependence of LiF:Mg,Ti thermoluminescent dosimeters (TLD-100) for 125 I and 103 Pd brachytherapy sources relative to 60 Co. Methods: LiF:Mg,Ti TLDs were irradiated with low-energy brachytherapy sources and with a 60 Co teletherapy source. The brachytherapy sources measured were the Best 2301 125 I seed, the OncoSeed 6711 125 I seed, and the Best 2335 103 Pd seed. The TLD light output per measured air-kerma strength was determined for the brachytherapy source irradiations, and the TLD light output per air kerma was determined for the 60 Co irradiations. Monte Carlo (MC) simulations were used to calculate the dose-to-TLD rate per air-kerma strength for the brachytherapy source irradiations and the dose to TLD per air kerma for the 60 Co irradiations. The measured and MC-calculated results for all irradiations were used to determine the TLD intrinsic energy dependence for 125 I and 103 Pd relative to 60 Co. Results: The relative TLD intrinsic energy dependences (relative to 60 Co) and associated uncertainties (k = 1) were determined to be 0.883 ± 1.3%, 0.870 ± 1.4%, and 0.871 ± 1.5% for the Best 2301 seed, OncoSeed 6711 seed, and Best 2335 seed, respectively. Conclusions: The intrinsic energy dependence of TLD-100 is dependent on photon energy, exhibiting changes of 13%–15% for 125 I and 103 Pd sources relative to 60 Co. TLD measurements of absolute dose around 125 I and 103 Pd brachytherapy sources should explicitly account for the relative TLD intrinsic energy dependence in order to improve dosimetric accuracy

  6. Dose Distributions of an 192Ir Brachytherapy Source in Different Media

    Directory of Open Access Journals (Sweden)

    C. H. Wu

    2014-01-01

    Full Text Available This study used MCNPX code to investigate the brachytherapy 192Ir dose distributions in water, bone, and lung tissue and performed radiophotoluminescent glass dosimeter measurements to verify the obtained MCNPX results. The results showed that the dose-rate constant, radial dose function, and anisotropy function in water were highly consistent with data in the literature. However, the lung dose near the source would be overestimated by up to 12%, if the lung tissue is assumed to be water, and, hence, if a tumor is located in the lung, the tumor dose will be overestimated, if the material density is not taken into consideration. In contrast, the lung dose far from the source would be underestimated by up to 30%. Radial dose functions were found to depend not only on the phantom size but also on the material density. The phantom size affects the radial dose function in bone more than those in the other tissues. On the other hand, the anisotropy function in lung tissue was not dependent on the radial distance. Our simulation results could represent valid clinical reference data and be used to improve the accuracy of the doses delivered during brachytherapy applied to patients with lung cancer.

  7. Influence of radioactive sources discretization in the Monte Carlo computational simulations of brachytherapy procedures: a case study on the procedures for treatment of prostate cancer

    International Nuclear Information System (INIS)

    Barbosa, Antonio Konrado de Santana; Vieira, Jose Wilson; Costa, Kleber Souza Silva; Lima, Fernando Roberto de Andrade

    2011-01-01

    Radiotherapy computational simulation procedures using Monte Carlo (MC) methods have shown to be increasingly important to the improvement of cancer fighting strategies. One of the biases in this practice is the discretization of the radioactive source in brachytherapy simulations, which often do not match with a real situation. This study had the aim to identify and to measure the influence of radioactive sources discretization in brachytherapy MC simulations when compared to those that do not present discretization, using prostate brachytherapy with Iodine-125 radionuclide as model. Simulations were carried out with 108 events with both types of sources to compare them using EGSnrc code associated to MASH phantom in orthostatic and supine positions with some anatomic adaptations. Significant alterations were found, especially regarding bladder, rectum and the prostate itself. It can be concluded that there is a need to discretized sources in brachytherapy simulations to ensure its representativeness. (author)

  8. Study of the shielding for spontaneous fission sources of Californium-252; Estudio de blindaje para fuentes de fision espontanea de Californio-252

    Energy Technology Data Exchange (ETDEWEB)

    Davila R, I

    1991-06-15

    A shielding study is made to attenuate, until maximum permissible levels, the neutrons radiation and photons emitted by spontaneous fission coming from a source of Californium-252. The compound package by a database (Library DLC-23) and the ANISNW code is used, in it version for personal computer. (Author)

  9. American brachytherapy society (ABS) guidelines for brachytherapy of esophageal cancer

    International Nuclear Information System (INIS)

    Nag, Subir; Gaspar, Laurie; Herskovic, Arnold; Mantravadi, Prasad; Speiser, Burton

    1996-01-01

    Introduction: There is wide variation in the indications, techniques, treatment regimens and dosimetry being used to treat cancer of the esophagus and no guidelines exist for optimal therapy. Methods: The Clinical Research Committee of the ABS met to formulate consensus guidelines for brachytherapy in esophageal cancer. Results: Good candidates for brachytherapy include patients with unifocal disease, with thoracic tumor 10 cm primary regional lymph adenopathy or tumor located in the gastro-esophageal junction or cervical esophagus. Contraindications include tracheo-esophageal fistula or stenosis that cannot be by-passed. The esophageal or nasogastric tube inserted should have a diameter of 6-10 mm whenever possible. If 5FU-based chemotherapy and 50 Gy external beam (EBRT) are used, it is suggested that the low dose rate brachytherapy (LDR) dose be 20 Gy at 0.4-1 Gy/hr, prescribed at 1 cm from the source. If high dose rate (HDR) is used, the dose recommended is 10 Gy in 2 weekly fractions of 5 Gy each, given after EBRT. Chemotherapy is not usually given concurrently with brachytherapy, and when it is, the brachytherapy dose is reduced. The length of esophagus treated by brachytherapy includes the post-EBRT involved area and a 1-2 cm margin proximally and distally. Supportive care, given during EBRT includes an antifungal agent (e.g., diflucan) and carafate. Gradual dilatation of the esophagus is required post-treatment for esophageal strictures. Conclusion: Guidelines were developed for brachytherapy in esophageal cancer. As more clinical data becomes available, these guidelines will be updated by the ABS

  10. Dosimetry audit on the accuracy of 192Ir brachytherapy source strength determinations in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson Tedgren, Aasa

    2007-11-15

    The absorbed dose delivered to the patient in brachytherapy is directly proportional to the source strength in terms of the reference air-kerma rate (RAKR). Verification of this quantity by the hospitals is widely recognized as an important part of a quality assurance program. An external audit was performed on behalf of the Secondary Standard Dosimetry Laboratory at the Swedish Radiation Protection Authority (SSI). The aim was to investigate how accurately the source-strength in 192Ir brachytherapy is determined at Swedish hospitals. The SSI reference well-type ion chamber and calibrated equipment were used to measure the RAKR of an 192Ir source in each of the 14 Swedish afterloading units. Comparisons with values determined by vendors and hospitals were made. Agreement in values of RAKR as determined by SSI, hospitals and vendors were in all cases within the +-3% uncertainty (at a coverage factor of k=2), typically guaranteed by the vendors. The good agreement reflects the robustness and easy handling of well-type chambers designed for brachytherapy in use by all Swedish hospitals. The 192Ir calibration service planned at SSI will solve the hospitals current problem with recalibration of equipment. SSI can also advise hospitals to follow the IAEA recommendations for measurement techniques and maintenance of equipment. It is worthwhile for the hospitals to establish their own ratio (or deviation) with the vendor and follow it as function of time. Such a mean-ratio embeds systematic differences of various origins and have a lower uncertainty than has the RAKR alone, making it useful for early detection of problems with equipment or routines. SSI could also define requirements for the agreement between source strengths as determined by hospitals and vendors and couple this to an action plan, dependent on level of disagreement, and some kind of reporting to SSI

  11. Dosimetry audit on the accuracy of 192Ir brachytherapy source strength determinations in Sweden

    International Nuclear Information System (INIS)

    Carlsson Tedgren, Aasa

    2007-11-01

    The absorbed dose delivered to the patient in brachytherapy is directly proportional to the source strength in terms of the reference air-kerma rate (RAKR). Verification of this quantity by the hospitals is widely recognized as an important part of a quality assurance program. An external audit was performed on behalf of the Secondary Standard Dosimetry Laboratory at the Swedish Radiation Protection Authority (SSI). The aim was to investigate how accurately the source-strength in 192 Ir brachytherapy is determined at Swedish hospitals. The SSI reference well-type ion chamber and calibrated equipment were used to measure the RAKR of an 192 Ir source in each of the 14 Swedish afterloading units. Comparisons with values determined by vendors and hospitals were made. Agreement in values of RAKR as determined by SSI, hospitals and vendors were in all cases within the ±3% uncertainty (at a coverage factor of k=2), typically guaranteed by the vendors. The good agreement reflects the robustness and easy handling of well-type chambers designed for brachytherapy in use by all Swedish hospitals. The 192 Ir calibration service planned at SSI will solve the hospitals current problem with recalibration of equipment. SSI can also advise hospitals to follow the IAEA recommendations for measurement techniques and maintenance of equipment. It is worthwhile for the hospitals to establish their own ratio (or deviation) with the vendor and follow it as function of time. Such a mean-ratio embeds systematic differences of various origins and have a lower uncertainty than has the RAKR alone, making it useful for early detection of problems with equipment or routines. SSI could also define requirements for the agreement between source strengths as determined by hospitals and vendors and couple this to an action plan, dependent on level of disagreement, and some kind of reporting to SSI

  12. Dosimetric study of a brachytherapy treatment of esophagus with Brazilian 192Ir sources using an anthropomorphic phantom

    Science.gov (United States)

    Neves, Lucio P.; Santos, William S.; Gorski, Ronan; Perini, Ana P.; Maia, Ana F.; Caldas, Linda V. E.; Orengo, Gilberto

    2014-11-01

    Several radioisotopes are produced at Instituto de Pesquisas Energéticas e Nucleares for the use in medical treatments, including the activation of 192Ir sources. These sources are suitable for brachytherapy treatments, due to their low or high activity, depending on the concentration of 192Ir, easiness to manufacture, small size, stable daughter products and the possibility of re-utilization. They may be used for the treatment of prostate, cervix, head and neck, skin, breast, gallbladder, uterus, vagina, lung, rectum, and eye cancer treatment. In this work, the use of some 192Ir sources was studied for the treatment of esophagus cancer, especially the dose determination of important structures, such as those on the mediastinum. This was carried out utilizing a FASH anthropomorphic phantom and the MCNP5 Monte Carlo code to transport the radiation through matter. It was possible to observe that the doses at lungs, breast, esophagus, thyroid and heart were the highest, which was expected due to their proximity to the source. Therefore, the data are useful to assess the representative dose specific to brachytherapy treatments on the esophagus for radiation protection purposes. The use of brachytherapy sources was studied for the treatment of esophagus cancer. FASH anthropomorphic phantom and MCNP5 Monte Carlo code were employed. The doses at lungs, breast, esophagus, thyroid and heart were the highest. The data is useful to assess the representative doses of treatments on the esophagus.

  13. Neutron sources and its dosimetric characteristics; Fuentes de neutrones y sus caracteristicas dosimetricas

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R.; Manzanares A, E.; Hernandez D, V.M.; Mercado S, G.A. [Universidad Autonoma de Zacatecas, A.P. 336, 98000 Zacatecas (Mexico); Gallego D, E.; Lorente F, A. [Universidad Politecnica de Madrid, C/Jose Gutierrez Abascal 2, E-28006 Madrid (Spain)

    2005-07-01

    By means of Monte Carlo methods the spectra of the produced neutrons {sup 252} Cf, {sup 252} Cf/D{sub 2}O, {sup 241} Am Be, {sup 239} Pu Be, {sup 140} La Be, {sup 239} Pu{sup 18}O{sub 2} and {sup 226} Ra Be have been calculated. With the information of the spectrum it was calculated the average energy of the neutrons of each source. By means of the fluence coefficients to dose it was determined, for each one of the studied sources, the fluence factors to dose. The calculated doses were H, H{sup *}(10), H{sub p,sIab} (10, 0{sup 0}), E{sub AP} and E{sub ISO}. During the phase of the calculations the sources were modeled as punctual and their characteristics were determined to 100 cm in the hole. Also, for the case of the sources of {sup 239} Pu Be and {sup 241} Am Be, were carried out calculations modeling the sources with their respective characteristics and the dosimetric properties were determined in a space full with air. The results of this last phase of the calculations were compared with the experimental results obtained for both sources. (Author)

  14. Monte Carlo dosimetric characterization of the Flexisource Co-60 high-dose-rate brachytherapy source using PENELOPE.

    Science.gov (United States)

    Almansa, Julio F; Guerrero, Rafael; Torres, Javier; Lallena, Antonio M

    60 Co sources have been commercialized as an alternative to 192 Ir sources for high-dose-rate (HDR) brachytherapy. One of them is the Flexisource Co-60 HDR source manufactured by Elekta. The only available dosimetric characterization of this source is that of Vijande et al. [J Contemp Brachytherapy 2012; 4:34-44], whose results were not included in the AAPM/ESTRO consensus document. In that work, the dosimetric quantities were calculated as averages of the results obtained with the Geant4 and PENELOPE Monte Carlo (MC) codes, though for other sources, significant differences have been quoted between the values obtained with these two codes. The aim of this work is to perform the dosimetric characterization of the Flexisource Co-60 HDR source using PENELOPE. The MC simulation code PENELOPE (v. 2014) has been used. Following the recommendations of the AAPM/ESTRO report, the radial dose function, the anisotropy function, the air-kerma strength, the dose rate constant, and the absorbed dose rate in water have been calculated. The results we have obtained exceed those of Vijande et al. In particular, the absorbed dose rate constant is ∼0.85% larger. A similar difference is also found in the other dosimetric quantities. The effect of the electrons emitted in the decay of 60 Co, usually neglected in this kind of simulations, is significant up to the distances of 0.25 cm from the source. The systematic and significant differences we have found between PENELOPE results and the average values found by Vijande et al. point out that the dosimetric characterizations carried out with the various MC codes should be provided independently. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  15. A californium-252 source for radiobiological studies at Hiroshima University

    International Nuclear Information System (INIS)

    Kato, Kazuo; Takeoka, Seiji; Kuroda, Tokue; Tsujimura, Tomotaka; Kawami, Masaharu; Hoshi, Masaharu; Sawada, Shozo

    1987-01-01

    A 1.93 Ci (3.6 mg) californium-252 source was installed in the radiation facility of the Research Institute for Nuclear Medicine and Biology, Hiroshima University. This source produces fission neutrons (8.7 x 10 9 n/s at the time of its installation), which are similar to neutron spectrum of the atomic bombs. It is useful for studying biological effects of fission neutrons and neutron dosimetry. An apparatus was dosigned to accomodate this source and to apply it to such studies. It has resulted in profitable fission neutron exposures, while suppressing scattered neutrons and secondary gamma rays. This apparatus incorporates many safety systems, including one which interlocks with all of doors and an elevator serving the exposure room, so as to prevent accidents involving users. (author)

  16. Study and methodologies for fixing epoxy resin in radioactive sources used for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Bruna T.; Rostelato, Maria E.C.M.; Souza, Carla D.; Tozetti, Cíntia A.; Zeituni, Carlos A.; Nogueira, Beatriz R.; Silva, José T.; Júnior, Dib K.; Fernandes, Vagner; Souza, Raquel V.; Abreu, Rodrigo T., E-mail: bteigarodrigues@gmail.com, E-mail: elisaros@ipen.br, E-mail: carladdsouza@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Universidade de São Paulo (USP), SP (Brazil)

    2017-07-01

    The World Health Organization (WHO) estimates that the number of new cancer cases worldwide will reach 15 million by 2020. The disease is already the second leading cause of death worldwide, being behind only cardiovascular disease. It is unquestionable that it is a public health problem, especially among developing countries. Prostate cancer is the most common among men, approximately 28.6%. The choice of type of treatment for prostate cancer should consider several factors such as: tumor size and extent, apparent aggressiveness (pathological characteristics), age, health. Among the methods applied, brachytherapy has been used in the initial and intermediate stages of the disease. Brachytherapy is a safe and effective treatment for localized prostate cancer. Brachytherapy is a form of radiotherapy in which radioactive seeds are placed in contact with or within the organ being treated. This technique allows a large dose of radiation to be released only on the target tumor that protects healthy surrounding tissues. Sources may have different shapes and sizes, but the one used for prostate cancer is usually 4.5 mm in length and 0.8 mm in diameter. About 80 to 120 seeds can be used per patient. Iodine-125 is the radioisotope most used in brachytherapy of the prostate, it emits 35,49keV X-rays in 100% of the decays, with average energy of 29 keV. The treatment of prostate cancer with permanent implantation of iodine-125 seeds has grown dramatically in the world in recent years. Most patients can return to normal life within three days with little or no pain. (author)

  17. Study and methodologies for fixing epoxy resin in radioactive sources used for brachytherapy

    International Nuclear Information System (INIS)

    Rodrigues, Bruna T.; Rostelato, Maria E.C.M.; Souza, Carla D.; Tozetti, Cíntia A.; Zeituni, Carlos A.; Nogueira, Beatriz R.; Silva, José T.; Júnior, Dib K.; Fernandes, Vagner; Souza, Raquel V.; Abreu, Rodrigo T.

    2017-01-01

    The World Health Organization (WHO) estimates that the number of new cancer cases worldwide will reach 15 million by 2020. The disease is already the second leading cause of death worldwide, being behind only cardiovascular disease. It is unquestionable that it is a public health problem, especially among developing countries. Prostate cancer is the most common among men, approximately 28.6%. The choice of type of treatment for prostate cancer should consider several factors such as: tumor size and extent, apparent aggressiveness (pathological characteristics), age, health. Among the methods applied, brachytherapy has been used in the initial and intermediate stages of the disease. Brachytherapy is a safe and effective treatment for localized prostate cancer. Brachytherapy is a form of radiotherapy in which radioactive seeds are placed in contact with or within the organ being treated. This technique allows a large dose of radiation to be released only on the target tumor that protects healthy surrounding tissues. Sources may have different shapes and sizes, but the one used for prostate cancer is usually 4.5 mm in length and 0.8 mm in diameter. About 80 to 120 seeds can be used per patient. Iodine-125 is the radioisotope most used in brachytherapy of the prostate, it emits 35,49keV X-rays in 100% of the decays, with average energy of 29 keV. The treatment of prostate cancer with permanent implantation of iodine-125 seeds has grown dramatically in the world in recent years. Most patients can return to normal life within three days with little or no pain. (author)

  18. Study of Different Tissue Density Effects on the Dose Distribution of a 103Pd Brachytherapy Source Model MED3633

    Directory of Open Access Journals (Sweden)

    Ali Asghar Mowlavi

    2010-09-01

    Full Text Available Introduction: Clinical application of encapsulated radioactive brachytherapy sources has a major role in cancer treatment. In the present research, the effects of different tissue densities on the dose distribution of a 103Pd brachytherapy source in a spherical phantom of 50 cm radius have been studied. Material and Methods: As is well known, absorbed dose in tissue depends to its density, but this difference is not clear in measurements. Therefore, we applied the MCNP code to evaluate the effect of density on the dose distribution. 103Pd brachytherapy sources are used to treat prostate, breast and other cancers. Results: Absorbed dose has been calculated and presented around a source placed in the center of the phantom for different tissue densities. Also, we derived anisotropy and radial dose functions and compared our Monte Carlo results with experimental results of Rivard and Li et al. for F(1, θ and g(r in 1.040 g/cm3 tissue. Conclusion: The results of this study show that relative dose variations around the source center are very considerable at different densities, because of the presence of a photoabsorber (Au-Cu alloy in the source core. Dose variation exceeds 80% at the point (Z = 2.4 mm, Y = 0 mm. Computed values of anisotropy and radial dose functions are in good agreement with the experimental results of Rivard and Li et al.

  19. A robotic device for MRI-guided prostate brachytherapy

    NARCIS (Netherlands)

    Lagerburg, V.

    2008-01-01

    One of the treatment options for prostate cancer is brachytherapy with iodine-125 sources. In prostate brachytherapy a high radiation dose is delivered to the prostate with a steep dose fall off to critical surrounding organs. The implantation of the iodine sources is currently performed under

  20. Investigations into the Optimization of Multi-Source Strength Brachytherapy Treatment Procedures

    CERN Document Server

    Henderson, D L; Yoo, S

    2002-01-01

    The goal of this project is to investigate the use of multi-strength and multi-specie radioactive sources in permanent prostate implant brachytherapy. In order to fulfill the requirement for an optimal dose distribution, the prescribed dose should be delivered to the target in a nearly uniform dose distribution while simultaneously sparing sensitive structures. The treatment plan should use a small number of needles and sources while satisfying the treatment requirements. The hypothesis for the use of multi-strength and/or multi-specie sources is that a better treatment plan using fewer sources and needles could be obtained than by treatment plans using single-strength sources could reduce the overall number of sources used for treatment. We employ a recently developed greedy algorithm based on the adjoint concept as the optimization search engine. The algorithm utilizes and ''adjoint ratio'', which provides a means of ranking source positions, as the pseudo-objective function. It ha s been shown that the gre...

  1. Unification of a common biochemical failure definition for prostate cancer treated with brachytherapy or external beam radiotherapy with or without androgen deprivation

    International Nuclear Information System (INIS)

    Fitch, Dwight L.; McGrath, Samuel; Martinez, Alvaro A.; Vicini, Frank A.; Kestin, Larry L.

    2006-01-01

    Purpose: Minimal data are available regarding selection of an optimal biochemical failure (BF) definition for patients treated with brachytherapy, external beam radiotherapy (EBRT), and combinations of these treatments with or without androgen deprivation (AD). We retrospectively analyzed our institution's experience treating localized prostate cancer in an attempt to determine a BF definition that could be applied for these various treatment modalities. Methods and Materials: A total of 2376 patients with clinical stage T1-T3 N0 M0 prostate cancer were treated with conventional dose (median, 66.6 Gy) EBRT (n = 1201), high-dose (median, 75.6 Gy) adaptive radiation therapy (n = 465), EBRT + high-dose-rate brachytherapy boost (n 416), or brachytherapy alone (n = 294) between 1987 and 2003. A total of 496 patients (21%) received neoadjuvant AD with radiation therapy. There were 21924 posttreatment prostate-specific antigen (PSA) measurements. Multiple BF definitions were tested for their sensitivity, specificity, positive predictive value (+PV), and negative PV (-PV) in predicting subsequent clinical failure (CF) (any local failure or distant metastasis), overall survival (OS), and cause-specific survival (CSS). Median follow-up was 4.5 years. The date of BF was the date BF criteria were met (e.g., date of third rise). Results: A total of 290 patients (12%) experienced CF at a median interval of 3.6 years (range, 0.2-15.2 years). The 5- and 10-year CF rates were 12% and 26%, respectively. Three consecutive rises yielded a 46% sensitivity and 84% specificity for predicting CF. The 10-year CF for those 475 patients who experienced three rises (BF) was 37% vs. 17% for those patients who did not meet these criteria (biochemically controlled [BC]). For all patients, the following definitions were superior to three rises for predicting CF for both +PV, and -PV: n + 1 (≥1 ng/mL above nadir), n + 2, n + 3, threshold 2 (any PSA ≥2.0 ng/mL at or after nadir), threshold 3

  2. Directional interstitial brachytherapy from simulation to application

    Science.gov (United States)

    Lin, Liyong

    Organs at risk (OAR) are sometimes adjacent to or embedded in or overlap with the clinical target volume (CTV) to be treated. The purpose of this PhD study is to develop directionally low energy gamma-emitting interstitial brachytherapy sources. These sources can be applied between OAR to selectively reduce hot spots in the OARs and normal tissues. The reduction of dose over undesired regions can expand patient eligibility or reduce toxicities for the treatment by conventional interstitial brachytherapy. This study covers the development of a directional source from design optimization to construction of the first prototype source. The Monte Carlo code MCNP was used to simulate the radiation transport for the designs of directional sources. We have made a special construction kit to assemble radioactive and gold-shield components precisely into D-shaped titanium containers of the first directional source. Directional sources have a similar dose distribution as conventional sources on the treated side but greatly reduced dose on the shielded side, with a sharp dose gradient between them. A three-dimensional dose deposition kernel for the 125I directional source has been calculated. Treatment plans can use both directional and conventional 125I sources at the same source strength for low-dose-rate (LDR) implants to optimize the dose distributions. For prostate tumors, directional 125I LDR brachytherapy can potentially reduce genitourinary and gastrointestinal toxicities and improve potency preservation for low risk patients. The combination of better dose distribution of directional implants and better therapeutic ratio between tumor response and late reactions enables a novel temporary LDR treatment, as opposed to permanent or high-dose-rate (HDR) brachytherapy for the intermediate risk T2b and high risk T2c tumors. Supplemental external-beam treatments can be shortened with a better brachytherapy boost for T3 tumors. In conclusion, we have successfully finished the

  3. Non-uniform dwell times in line source high dose rate brachytherapy: physical and radiobiological considerations

    International Nuclear Information System (INIS)

    Jones, B.; Tan, L.T.; Freestone, G.; Bleasdale, C.; Myint, S.; Littler, J.

    1994-01-01

    The ability to vary source dwell times in high dose rate (HDR) brachytherapy allows for the use of non-uniform dwell times along a line source. This may have advantages in the radical treatment of tumours depending on individual tumour geometry. This study investigates the potential improvements in local tumour control relative to adjacent normal tissue isoeffects when intratumour source dwell times are increased along the central portion of a line source (technique A) in radiotherapy schedules which include a relatively small component of HDR brachytherapy. Such a technique is predicted to increase the local control for tumours of diameters ranging between 2 cm and 4 cm by up to 11% compared with a technique in which there are uniform dwell times along the line source (technique B). There is no difference in the local control rates for the two techniques when used to treat smaller tumours. Normal tissue doses are also modified by the technique used. Technique A produces higher normal tissue doses at points perpendicular to the centre of the line source and lower dose at points nearer the ends of the line source if the prescription point is not in the central plane of the line source. Alternatively, if the dose is prescribed at a point in the central plane of the line source, the dose at all the normal tissue points are lower when technique A is used. (author)

  4. Dosimetry audit on the accuracy of {sup 192}Ir brachytherapy source strength determinations in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson Tedgren, Aasa

    2007-11-15

    The absorbed dose delivered to the patient in brachytherapy is directly proportional to the source strength in terms of the reference air-kerma rate (RAKR). Verification of this quantity by the hospitals is widely recognized as an important part of a quality assurance program. An external audit was performed on behalf of the Secondary Standard Dosimetry Laboratory at the Swedish Radiation Protection Authority (SSI). The aim was to investigate how accurately the source-strength in {sup 192}Ir brachytherapy is determined at Swedish hospitals. The SSI reference well-type ion chamber and calibrated equipment were used to measure the RAKR of an {sup 192}Ir source in each of the 14 Swedish afterloading units. Comparisons with values determined by vendors and hospitals were made. Agreement in values of RAKR as determined by SSI, hospitals and vendors were in all cases within the {+-}3% uncertainty (at a coverage factor of k=2), typically guaranteed by the vendors. The good agreement reflects the robustness and easy handling of well-type chambers designed for brachytherapy in use by all Swedish hospitals. The {sup 192}Ir calibration service planned at SSI will solve the hospitals current problem with recalibration of equipment. SSI can also advise hospitals to follow the IAEA recommendations for measurement techniques and maintenance of equipment. It is worthwhile for the hospitals to establish their own ratio (or deviation) with the vendor and follow it as function of time. Such a mean-ratio embeds systematic differences of various origins and have a lower uncertainty than has the RAKR alone, making it useful for early detection of problems with equipment or routines. SSI could also define requirements for the agreement between source strengths as determined by hospitals and vendors and couple this to an action plan, dependent on level of disagreement, and some kind of reporting to SSI.

  5. Fitting and benchmarking of Monte Carlo output parameters for iridium-192 high dose rate brachytherapy source

    International Nuclear Information System (INIS)

    Acquah, F.G.

    2011-01-01

    Brachytherapy, the use of radioactive sources for the treatment of tumours is an important tool in radiation oncology. Accurate calculations of dose delivered to malignant and normal tissues are the main responsibility of the Medical Physics staff. With the use of Treatment Planning System (TPS) computers now becoming a standard practice in the Radiation Oncology Departments, Independent calculations to certify the results of these commercial TPSs are important part of a good quality management system for brachytherapy implants. There are inherent errors in the dose distributions produced by these TPSs due to its failure to account for heterogeneity in the calculation algorithms and Monte Carlo (MC) method seems to be the panacea for these corrections. In this study, a fit functional form using MC output parameters was performed to reduce dose calculation uncertainty using the Matlab software curve fitting applications. This includes the modification of the AAPM TG-43 parameters to accommodate the new developments for a rapid brachytherapy dose rate calculation. Analytical computations were performed to hybridize the anisotropy function, F(r,θ) and radial dose function, g(r) into a single new function f(r,θ) for the Nucletron microSelectron High Dose Rate 'new or v2' (mHDRv2) 192 Ir brachytherapy source. In order to minimize computation time and to improve the accuracy of manual calculations, the dosimetry function f(r,θ) used fewer parameters and formulas for the fit. Using MC outputs as the standard, the percentage errors for the fits were calculated and used to evaluate the average and maximum uncertainties. Dose rate deviation between the MC data and fit were also quantified as errors(E), which showed minimal values. These results showed that the dosimetry parameters from this study as compared to those of MC outputs parameters were in good agreement and better than the results obtained from literature. The work confirms a lot of promise in building robust

  6. The American Brachytherapy Society recommendations for low-dose-rate brachytherapy for carcinoma of the cervix

    International Nuclear Information System (INIS)

    Nag, Subir; Chao, Clifford; Erickson, Beth; Fowler, Jeffery; Gupta, Nilendu; Martinez, Alvaro; Thomadsen, Bruce

    2002-01-01

    Purpose: This report presents guidelines for using low-dose-rate (LDR) brachytherapy in the management of patients with cervical cancer. Methods: Members of the American Brachytherapy Society (ABS) with expertise in LDR brachytherapy for cervical cancer performed a literature review, supplemented by their clinical experience, to formulate guidelines for LDR brachytherapy of cervical cancer. Results: The ABS strongly recommends that radiation treatment for cervical carcinoma (with or without chemotherapy) should include brachytherapy as a component. Precise applicator placement is essential for improved local control and reduced morbidity. The outcome of brachytherapy depends, in part, on the skill of the brachytherapist. Doses given by external beam radiotherapy and brachytherapy depend upon the initial volume of disease, the ability to displace the bladder and rectum, the degree of tumor regression during pelvic irradiation, and institutional practice. The ABS recognizes that intracavitary brachytherapy is the standard technique for brachytherapy for cervical carcinoma. Interstitial brachytherapy should be considered for patients with disease that cannot be optimally encompassed by intracavitary brachytherapy. The ABS recommends completion of treatment within 8 weeks, when possible. Prolonging total treatment duration can adversely affect local control and survival. Recommendations are made for definitive and postoperative therapy after hysterectomy. Although recognizing that many efficacious LDR dose schedules exist, the ABS presents suggested dose and fractionation schemes for combining external beam radiotherapy with LDR brachytherapy for each stage of disease. The dose prescription point (point A) is defined for intracavitary insertions. Dose rates of 0.50 to 0.65 Gy/h are suggested for intracavitary brachytherapy. Dose rates of 0.50 to 0.70 Gy/h to the periphery of the implant are suggested for interstitial implant. Use of differential source activity or

  7. SU-E-T-155: Calibration of Variable Longitudinal Strength 103Pd Brachytherapy Sources

    International Nuclear Information System (INIS)

    Reed, J; Radtke, J; Micka, J; Culberson, W; DeWerd, L

    2015-01-01

    Purpose: Brachytherapy sources with variable longitudinal strength (VLS) allow for a customized intensity along the length of the source. These have applications in focal brachytherapy treatments of prostate cancer where dose boosting can be achieved through modulation of intra-source strengths. This work focused on development of a calibration methodology for VLS sources based on measurements and Monte Carlo (MC) simulations of five 1 cm 10 3 Pd sources each containing four regions of variable 103 Pd strength. Methods: The air-kerma strengths of the sources were measured with a variable-aperture free-air chamber (VAFAC). Source strengths were also measured using a well chamber. The in-air azimuthal and polar anisotropy of the sources were measured by rotating them in front of a NaI scintillation detector and were calculated with MC simulations. Azimuthal anisotropy results were normalized to their mean intensity values. Polar anisotropy results were normalized to their average transverse axis intensity values. The relative longitudinal strengths of the sources were measured via on-contact irradiations with radiochromic film, and were calculated with MC simulations. Results: The variable 103 Pd loading of the sources was validated by VAFAC and well chamber measurements. Ratios of VAFAC air-kerma strengths and well chamber responses were within ±1.3% for all sources. Azimuthal anisotropy results indicated that ≥95% of the normalized values for all sources were within ±1.7% of the mean values. Polar anisotropy results indicated variations within ±0.3% for a ±7.6° angular region with respect to the source transverse axis. Locations and intensities of the 103 Pd regions were validated by radiochromic film measurements and MC simulations. Conclusion: The calibration methodology developed in this work confirms that the VLS sources investigated have a high level of polar uniformity, and that the strength and longitudinal intensity can be verified experimentally and

  8. Proposal of a postal system for Ir-192 sources calibration used in high dose rate brachytherapy with LiF:Mn:Ti thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Vieira, W.S.; Borges, J.C.; Almeida, C.E.V.

    1998-01-01

    A proposal in order to improve the brachytherapy quality control and to allow postal intercomparison of Ir-192 sources used in high dose rate brachytherapy has been presented. The LiF: Mn: Ti (TLD 100) detector has been selected for such purpose. The experimental array and the TLDs irradiation and calibration techniques, at the treatment units, have been specified in the light of more recent methodology of Ir-192 calibration sources. (Author)

  9. Development of an asymmetric multiple-position neutron source (AMPNS) method to monitor the criticality of a degraded reactor core

    International Nuclear Information System (INIS)

    Kim, S.S.; Levine, S.H.

    1985-01-01

    An analytical/experimental method has been developed to monitor the subcritical reactivity and unfold the k/sub infinity/ distribution of a degraded reactor core. The method uses several fixed neutron detectors and a Cf-252 neutron source placed sequentially in multiple positions in the core. Therefore, it is called the Asymmetric Multiple Position Neutron Source (AMPNS) method. The AMPNS method employs nucleonic codes to analyze the neutron multiplication of a Cf-252 neutron source. An optimization program, GPM, is utilized to unfold the k/sub infinity/ distribution of the degraded core, in which the desired performance measure minimizes the error between the calculated and the measured count rates of the degraded reactor core. The analytical/experimental approach is validated by performing experiments using the Penn State Breazeale TRIGA Reactor (PSBR). A significant result of this study is that it provides a method to monitor the criticality of a damaged core during the recovery period

  10. Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

    Science.gov (United States)

    Shi, Chengyu; Guo, Bingqi; Cheng, Chih-Yao; Eng, Tony; Papanikolaou, Nikos

    2010-09-01

    A low-energy electronic brachytherapy source (EBS), the model S700 Axxent™ x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V100 reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as compared to 95

  11. Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Shi Chengyu; Guo Bingqi; Eng, Tony; Papanikolaou, Nikos [Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, TX 78229 (United States); Cheng, Chih-Yao, E-mail: shic@uthscsa.ed [Radiation Oncology Department, Oklahoma University Health Science Center, Oklahoma, OK 73104 (United States)

    2010-09-21

    A low-energy electronic brachytherapy source (EBS), the model S700 Axxent(TM) x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V{sub 100} reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as

  12. Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

    International Nuclear Information System (INIS)

    Shi Chengyu; Guo Bingqi; Eng, Tony; Papanikolaou, Nikos; Cheng, Chih-Yao

    2010-01-01

    A low-energy electronic brachytherapy source (EBS), the model S700 Axxent(TM) x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V 100 reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as compared to 95

  13. Current status of brachytherapy in Korea: a national survey of radiation oncologists.

    Science.gov (United States)

    Kim, Haeyoung; Kim, Joo Young; Kim, Juree; Park, Won; Kim, Young Seok; Kim, Hak Jae; Kim, Yong Bae

    2016-07-01

    The aim of the present study was to acquire information on brachytherapy resources in Korea through a national survey of radiation oncologists. Between October 2014 and January 2015, a questionnaire on the current status of brachytherapy was distributed to all 86 radiation oncology departments in Korea. The questionnaire was divided into sections querying general information on human resources, brachytherapy equipment, and suggestions for future directions of brachytherapy policy in Korea. The response rate of the survey was 88.3%. The average number of radiation oncologists per center was 2.3. At the time of survey, 28 centers (36.8%) provided brachytherapy to patients. Among the 28 brachytherapy centers, 15 (53.5%) were located in in the capital Seoul and its surrounding metropolitan areas. All brachytherapy centers had a high-dose rate system using (192)Ir (26 centers) or (60)Co (two centers). Among the 26 centers using (192)Ir sources, 11 treated fewer than 40 patients per year. In the two centers using (60)Co sources, the number of patients per year was 16 and 120, respectively. The most frequently cited difficulties in performing brachytherapy were cost related. A total of 21 centers had a plan to sustain the current brachytherapy system, and four centers noted plans to upgrade their brachytherapy system. Two centers stated that they were considering discontinuation of brachytherapy due to cost burdens of radioisotope source replacement. The present study illustrated the current status of brachytherapy in Korea. Financial difficulties were the major barriers to the practice of brachytherapy.

  14. Monte Carlo simulations and radiation dosimetry measurements of 142Pr capillary tube-based radioactive implant (CTRI). A new structure for brachytherapy sources

    International Nuclear Information System (INIS)

    Bakht, M.K.; Haddadi, A.; Sadeghi, M.; Ahmadi, S.J.; Sadjadi, S.S.; Tenreiro, C.

    2013-01-01

    Previously, a promising β - -emitting praseodymium-142 glass seed was proposed for brachytherapy of prostate cancer. In accordance with the previous study, a 142 Pr capillary tube-based radioactive implant (CTRI) was suggested as a source with a new structure to enhance application of β - -emitting radioisotopes such as 142 Pr in brachytherapy. Praseodymium oxide powder was encapsulated in a glass capillary tube. Then, a thin and flexible fluorinated ethylene propylene Teflon layer sealed the capillary tube. The source was activated in the Tehran Research Reactor by the 141 Pr(n, γ) 142 Pr reaction. Measurements of the dosimetric parameters were performed using GafChromic radiochromic film. In addition, the dose rate distribution of 142 Pr CTRI was calculated by modeling 142 Pr source in a water phantom using Monte Carlo N-Particle Transport (MCNP5) Code. The active source was unreactive and did not leak in water. In comparison with the earlier proposed 142 Pr seed, the suggested source showed similar desirable dosimetric characteristics. Moreover, the 142 Pr CTRI production procedure may be technically and economically more feasible. The mass of praseodymium in CTRI structure could be greater than that of the 142 Pr glass seed; therefore, the required irradiation time and the neutron flux could be reduced. A 142 Pr CTRI was proposed for brachytherapy of prostate cancer. The dosimetric calculations by the experimental measurements and Monte Carlo simulation were performed to fulfill the requirements according to the American Association of Physicists in Medicine recommendations before the clinical use of new brachytherapy sources. The characteristics of the suggested source were compared with those of the previously proposed 142 Pr glass seed. (author)

  15. High dose-rate brachytherapy source localization: positional resolution using a diamond detector

    International Nuclear Information System (INIS)

    Nakano, T; Suchowerska, N; Bilek, M M; McKenzie, D R; Ng, N; Kron, T

    2003-01-01

    A potential real-time source position verification process for high dose-rate (HDR) brachytherapy treatment is described. This process is intended to provide immediate confirmation that a treatment is proceeding according to plan, so that corrective action can be taken if necessary. We show that three dosimeters are in principle sufficient and demonstrate the feasibility of the process using a diamond detector and an Ir-192 source. An error analysis including all identified sources of error shows that this detector is capable of locating the distance to the source to within 2 mm for distances up to 12 cm. This positional accuracy is less than the diameter of typical HDR catheters indicating that a diamond detector can be used to accurately determine the distance to the source. The uncertainty in the distance is found to increase with distance

  16. Energy spectrum based calculation of the half and the tenth value layers for brachytherapy sources using a semiempirical parametrized mass attenuation coefficient formulism

    International Nuclear Information System (INIS)

    Yue, Ning J.

    2008-01-01

    As different types of radionuclides (e.g., 131 Cs source) are introduced for clinical use in brachytherapy, the question is raised regarding whether a relatively simple method exists for the derivation of values of the half value layer (HVL) or the tenth value layer (TVL). For the radionuclide that has been clinically used for years, such as 125 I and 103 Pd, the sources have been manufactured and marketed by several vendors with different designs and structures. Because of the nature of emission of low energy photons for these radionuclides, energy spectra of the sources are very dependent on their individual designs. Though values of the HVL or the TVL in certain commonly used shielding materials are relatively small for these low energy photon emitting sources, the question remains how the variations in energy spectra affect the HVL (or TVL) values and whether these values can be calculated with a relatively simple method. A more fundamental question is whether a method can be established to derive the HVL (TVL) values for any brachytherapy sources and for different materials in a relatively straightforward fashion. This study was undertaken to answer these questions. Based on energy spectra, a well established semiempirical mass attenuation coefficient computing scheme was utilized to derive the HVL (TVL) values of different materials for different types of brachytherapy sources. The method presented in this study may be useful to estimate HVL (TVL) values of different materials for brachytherapy sources of different designs and containing different radionuclides

  17. Absolute measurement of LDR brachytherapy source emitted power: Instrument design and initial measurements.

    Science.gov (United States)

    Malin, Martha J; Palmer, Benjamin R; DeWerd, Larry A

    2016-02-01

    Energy-based source strength metrics may find use with model-based dose calculation algorithms, but no instruments exist that can measure the energy emitted from low-dose rate (LDR) sources. This work developed a calorimetric technique for measuring the power emitted from encapsulated low-dose rate, photon-emitting brachytherapy sources. This quantity is called emitted power (EP). The measurement methodology, instrument design and performance, and EP measurements made with the calorimeter are presented in this work. A calorimeter operating with a liquid helium thermal sink was developed to measure EP from LDR brachytherapy sources. The calorimeter employed an electrical substitution technique to determine the power emitted from the source. The calorimeter's performance and thermal system were characterized. EP measurements were made using four (125)I sources with air-kerma strengths ranging from 2.3 to 5.6 U and corresponding EPs of 0.39-0.79 μW, respectively. Three Best Medical 2301 sources and one Oncura 6711 source were measured. EP was also computed by converting measured air-kerma strengths to EPs through Monte Carlo-derived conversion factors. The measured EP and derived EPs were compared to determine the accuracy of the calorimeter measurement technique. The calorimeter had a noise floor of 1-3 nW and a repeatability of 30-60 nW. The calorimeter was stable to within 5 nW over a 12 h measurement window. All measured values agreed with derived EPs to within 10%, with three of the four sources agreeing to within 4%. Calorimeter measurements had uncertainties ranging from 2.6% to 4.5% at the k = 1 level. The values of the derived EPs had uncertainties ranging from 2.9% to 3.6% at the k = 1 level. A calorimeter capable of measuring the EP from LDR sources has been developed and validated for (125)I sources with EPs between 0.43 and 0.79 μW.

  18. Investigation of the Effects of Tissue Inhomogeneities on the Dosimetric Parameters of a Cs-137 Brachytherapy Source using the MCNP4C Code

    Directory of Open Access Journals (Sweden)

    Mehdi Zehtabian

    2010-09-01

    Full Text Available Introduction: Brachytherapy is the use of small encapsulated radioactive sources in close vicinity of tumors. Various methods are used to obtain the dose distribution around brachytherapy sources. TG-43 is a dosimetry protocol proposed by the AAPM for determining dose distributions around brachytherapy sources. The goal of this study is to update this protocol for presence of bone and air inhomogenities.  Material and Methods: To update the dose rate constant parameter of the TG-43 formalism, the MCNP4C simulations were performed in phantoms composed of water-bone and water-air combinations. The values of dose at different distances from the source in both homogeneous and inhomogeneous phantoms were estimated in spherical tally cells of 0.5 mm radius using the F6 tally. Results: The percentages of dose reductions in presence of air and bone inhomogenities for the Cs-137 source were found to be 4% and 10%, respectively. Therefore, the updated dose rate constant (Λ will also decrease by the same percentages.   Discussion and Conclusion: It can be easily concluded that such dose variations are more noticeable when using lower energy sources such as Pd-103 or I-125.

  19. WE-DE-201-08: Multi-Source Rotating Shield Brachytherapy Apparatus for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dadkhah, H; Wu, X [University of Iowa, Iowa City, Iowa (United States); Kim, Y; Flynn, R [University of Iowa Hospitals and Clinics, Iowa City, IA (United States)

    2016-06-15

    Purpose: To introduce a novel multi-source rotating shield brachytherapy (RSBT) apparatus for the precise simultaneous angular and linear positioning of all partially-shielded 153Gd radiation sources in interstitial needles for treating prostate cancer. The mechanism is designed to lower the detrimental dose to healthy tissues, the urethra in particular, relative to conventional high-dose-rate brachytherapy (HDR-BT) techniques. Methods: Following needle implantation, the delivery system is docked to the patient template. Each needle is coupled to a multi-source afterloader catheter by a connector passing through a shaft. The shafts are rotated by translating a moving template between two stationary templates. Shaft walls as well as moving template holes are threaded such that the resistive friction produced between the two parts exerts enough force on the shafts to bring about the rotation. Rotation of the shaft is then transmitted to the shielded source via several keys. Thus, shaft angular position is fully correlated with the position of the moving template. The catheter angles are simultaneously incremented throughout treatment as needed, and only a single 360° rotation of all catheters is needed for a full treatment. For each rotation angle, source depth in each needle is controlled by a multi-source afterloader, which is proposed as an array of belt-driven linear actuators, each of which drives a source wire. Results: Optimized treatment plans based on Monte Carlo dose calculations demonstrated RSBT with the proposed apparatus reduced urethral D{sub 1cc} below that of conventional HDR-BT by 35% for urethral dose gradient volume within 3 mm of the urethra surface. Treatment time to deliver 20 Gy with multi-source RSBT apparatus using nineteen 62.4 GBq {sup 153}Gd sources is 117 min. Conclusions: The proposed RSBT delivery apparatus in conjunction with multiple nitinol catheter-mounted platinum-shielded {sup 153}Gd sources enables a mechanically feasible

  20. Experimental and theoretical determination of dosimetric characteristics of IsoAid ADVANTAGETM125I brachytherapy source

    International Nuclear Information System (INIS)

    Meigooni, Ali S.; Hayes, Joshua L.; Zhang Hualin; Sowards, Keith

    2002-01-01

    125 I brachytherapy sources are being used for interstitial implants in tumor sites such as the prostate. Recently, the ADVANTAGE TM 125 I, Model IAI-125, source became commercially available for interstitial brachytherapy treatment. Dosimetric characteristics (dose rate constant, radial dose function, and anisotropy function) of this source were experimentally and theoretically determined, following the AAPM Task Group 43 recommendations. Derivation of the dose rate constant was based on recent NIST WAFAC calibration performed in accordance with their 1999 standard. Measurements were performed in Solid Water TM phantom using LiF thermoluminescent dosimeters. The theoretical calculations were performed in both Solid Water TM and water using the PTRAN Monte Carlo code. The results indicated that a dose rate constant of the new source in water was 0.98±0.03 cGy h -1 U -1 . The radial dose function of the new source was measured in Solid Water TM and calculated both in water and Solid Water TM at distances up to 10.0 cm. The anisotropy function, F(r,θ), of the new source was measured and calculated in Solid Water TM at distances of 2 cm, 3 cm, 5 cm, and 7 cm and also was calculated in water at distances ranging from 1 cm to 7 cm from the source. From the anisotropy function, the anisotropy factors and anisotropy constant were derived. The anisotropy constant of the ADVANTAGE TM 125 I source in water was found to be 0.97±0.03. The dosimetric characteristics of this new source compared favorably with those from the Amersham Health Model 6711 source. Complete dosimetric parameters of the new source are presented in this paper

  1. An orthodontic device for retaining implanted radioactive sources during brachytherapy for cancer of the oral cavity

    International Nuclear Information System (INIS)

    Masuko, Noriko; Katsura, Kouji; Sugita, Tadashi; Sakai, Kunio; Sato, Katsurou; Kawana, Masahiro; Nonomura, Naobumi

    2000-01-01

    An orthodontic retainer was devised to keeping implanted radioactive sources in position and improve the quality of life during brachytherapy for cancer of the oral cavity. The retainer was used in 3 patients with oral cancer, one with cancer of the hard palate, one with cancer of the soft palate, and one with cancer of the floor of mouth, during brachytherapy using 198 Au grains and 137 Cs needles. These patients could speak freely. One with cancer of the hard palate could drink water and ingest semi-liquid food during treatment instead of nasal tube feeding. The plaster dental model obtained while making the retainer proved to be useful for training radiation oncologists. (author)

  2. [Developments in brachytherapy].

    Science.gov (United States)

    Ikeda, H

    1995-09-01

    Brachytherapy is one of the ideal methods of radiotherapy because of the concentration of a high dose on the target. Recent developments, including induction of afterloading method, utilization of small-sized high-activity sources such as Iridium-192, and induction of high technology and computerization, have made for shortening of irradiation time and source handling, which has led to easier management of the patient during treatment. Dose distribution at high dose rate (HDR) is at least as good as that of low dose rate (LDR), and selection of fractionation and treatment time assures even greater biological effects on hypoxic tumor cells than LDR. Experience with HDR brachytherapy in uterine cervix cancer using Cobalt-60 during the past 20 years in this country has gradually been evaluated in U.S. and Europe. The indications for HDR treatment have extended to esophagus, bronchus, bile duct, brain, intraoperative placement of source guide, and perineal region using templates, as well as the conventional use for uterus, tongue and so on.

  3. The difference of scoring dose to water or tissues in Monte Carlo dose calculations for low energy brachytherapy photon sources.

    Science.gov (United States)

    Landry, Guillaume; Reniers, Brigitte; Pignol, Jean-Philippe; Beaulieu, Luc; Verhaegen, Frank

    2011-03-01

    The goal of this work is to compare D(m,m) (radiation transported in medium; dose scored in medium) and D(w,m) (radiation transported in medium; dose scored in water) obtained from Monte Carlo (MC) simulations for a subset of human tissues of interest in low energy photon brachytherapy. Using low dose rate seeds and an electronic brachytherapy source (EBS), the authors quantify the large cavity theory conversion factors required. The authors also assess whether ap plying large cavity theory utilizing the sources' initial photon spectra and average photon energy induces errors related to spatial spectral variations. First, ideal spherical geometries were investigated, followed by clinical brachytherapy LDR seed implants for breast and prostate cancer patients. Two types of dose calculations are performed with the GEANT4 MC code. (1) For several human tissues, dose profiles are obtained in spherical geometries centered on four types of low energy brachytherapy sources: 125I, 103Pd, and 131Cs seeds, as well as an EBS operating at 50 kV. Ratios of D(w,m) over D(m,m) are evaluated in the 0-6 cm range. In addition to mean tissue composition, compositions corresponding to one standard deviation from the mean are also studied. (2) Four clinical breast (using 103Pd) and prostate (using 125I) brachytherapy seed implants are considered. MC dose calculations are performed based on postimplant CT scans using prostate and breast tissue compositions. PTV D90 values are compared for D(w,m) and D(m,m). (1) Differences (D(w,m)/D(m,m)-1) of -3% to 70% are observed for the investigated tissues. For a given tissue, D(w,m)/D(m,m) is similar for all sources within 4% and does not vary more than 2% with distance due to very moderate spectral shifts. Variations of tissue composition about the assumed mean composition influence the conversion factors up to 38%. (2) The ratio of D90(w,m) over D90(m,m) for clinical implants matches D(w,m)/D(m,m) at 1 cm from the single point sources, Given

  4. Role of energy cost in the yield of cold ternary fission of Cf

    Indian Academy of Sciences (India)

    Abstract. The energy costs in the cold ternary fission of 252Cf for various light charged particle emission are calculated by including Wong's correction for Coulomb potential. Energy cost is found to be higher in cold fission than in normal fission. It is found that energy cost always increases with decrease in experimental yield ...

  5. Study on development and actual application of scientific crime detection technique using small scale neutron radiation source

    International Nuclear Information System (INIS)

    Suzuki, Yasuhiro; Kishi, Toru; Tachikawa, Noboru; Ishikawa, Isamu.

    1997-01-01

    PGA (Prompt γ-ray Analysis) is an analytic method of γ-ray generated from atomic nuclei of elements in the specimen just after irradiation (within 10(exp-14)sec.) of neutron to it. As using neutron with excellent transmission for an exciting source, this method can be used for inspecting the matters in closed containers non-destructively, and can also detect non-destructively light elements such as boron, nitrogen and others difficult by other non-destructive analysis. Especially, it is found that this method can detect such high concentration of nitrogen, chlorine and others which are characteristic elements for the explosives. However, as there are a number of limitations at the nuclear reactor site, development of an analytical apparatus for small scale neutron radiation source was begun, at first. In this fiscal year, analysis of the light elements such as nitrogen, chlorine and others using PGA was attempted by using 252-Cf as the simplest neutron source in its operation. As the 252-Cf neutron flux was considerably lower than that of nuclear reactor, its analytical sensitivity was also investigated. (G.K.)

  6. The mass transfer mechanism of fissile material due to fission

    International Nuclear Information System (INIS)

    Shafrir, N.H.

    1975-01-01

    A thin 252 Cf source of a mean thickness of an approXimately mono-atomic layer was used as an experimental model for the study of the basic mechanism of the knock-on process taking place in fissile material. Because of the thinness of the source it can be assumed that mainly primary knock-ons are formed. The ejection rate of knock-ons created by direct collisions between fission fragments and source atoms was measured as follows: the ejected atoms were collected in high vacuum on a catcher foil and 252 Cf determined by alpha spectroscopy using a silicon surface barrier detector. The number of 252 Cf ejected from the source in unit time could thus be determined while considering the anisotropy of ejection, geometry and counting efficiency. Taking into account the chemical composition of the source, eta(theor.) = 252 Cf atoms/fission was obtained. This result can be considered in reasonable agreement with experiment confirming that under the experimental conditions described, practically no knock-on cascade is formed. (B.G.)

  7. Calculation of integrated biological response in brachytherapy

    International Nuclear Information System (INIS)

    Dale, Roger G.; Coles, Ian P.; Deehan, Charles; O'Donoghue, Joseph A.

    1997-01-01

    Purpose: To present analytical methods for calculating or estimating the integrated biological response in brachytherapy applications, and which allow for the presence of dose gradients. Methods and Materials: The approach uses linear-quadratic (LQ) formulations to identify an equivalent biologically effective dose (BED eq ) which, if applied to a specified tissue volume, would produce the same biological effect as that achieved by a given brachytherapy application. For simple geometrical cases, BED multiplying factors have been derived which allow the equivalent BED for tumors to be estimated from a single BED value calculated at a dose reference point. For more complex brachytherapy applications a voxel-by-voxel determination of the equivalent BED will be more accurate. Equations are derived which when incorporated into brachytherapy software would facilitate such a process. Results: At both high and low dose rates, the BEDs calculated at the dose reference point are shown to be lower than the true values by an amount which depends primarily on the magnitude of the prescribed dose; the BED multiplying factors are higher for smaller prescribed doses. The multiplying factors are less dependent on the assumed radiobiological parameters. In most clinical applications involving multiple sources, particularly those in multiplanar arrays, the multiplying factors are likely to be smaller than those derived here for single sources. The overall suggestion is that the radiobiological consequences of dose gradients in well-designed brachytherapy treatments, although important, may be less significant than is sometimes supposed. The modeling exercise also demonstrates that the integrated biological effect associated with fractionated high-dose-rate (FHDR) brachytherapy will usually be different from that for an 'equivalent' continuous low-dose-rate (CLDR) regime. For practical FHDR regimes involving relatively small numbers of fractions, the integrated biological effect to

  8. Estimation of distance error by fuzzy set theory required for strength determination of HDR (192)Ir brachytherapy sources.

    Science.gov (United States)

    Kumar, Sudhir; Datta, D; Sharma, S D; Chourasiya, G; Babu, D A R; Sharma, D N

    2014-04-01

    Verification of the strength of high dose rate (HDR) (192)Ir brachytherapy sources on receipt from the vendor is an important component of institutional quality assurance program. Either reference air-kerma rate (RAKR) or air-kerma strength (AKS) is the recommended quantity to specify the strength of gamma-emitting brachytherapy sources. The use of Farmer-type cylindrical ionization chamber of sensitive volume 0.6 cm(3) is one of the recommended methods for measuring RAKR of HDR (192)Ir brachytherapy sources. While using the cylindrical chamber method, it is required to determine the positioning error of the ionization chamber with respect to the source which is called the distance error. An attempt has been made to apply the fuzzy set theory to estimate the subjective uncertainty associated with the distance error. A simplified approach of applying this fuzzy set theory has been proposed in the quantification of uncertainty associated with the distance error. In order to express the uncertainty in the framework of fuzzy sets, the uncertainty index was estimated and was found to be within 2.5%, which further indicates that the possibility of error in measuring such distance may be of this order. It is observed that the relative distance li estimated by analytical method and fuzzy set theoretic approach are consistent with each other. The crisp values of li estimated using analytical method lie within the bounds computed using fuzzy set theory. This indicates that li values estimated using analytical methods are within 2.5% uncertainty. This value of uncertainty in distance measurement should be incorporated in the uncertainty budget, while estimating the expanded uncertainty in HDR (192)Ir source strength measurement.

  9. Comprehensive brachytherapy physical and clinical aspects

    CERN Document Server

    Baltas, Dimos; Meigooni, Ali S; Hoskin, Peter J

    2013-01-01

    Modern brachytherapy is one of the most important oncological treatment modalities requiring an integrated approach that utilizes new technologies, advanced clinical imaging facilities, and a thorough understanding of the radiobiological effects on different tissues, the principles of physics, dosimetry techniques and protocols, and clinical expertise. A complete overview of the field, Comprehensive Brachytherapy: Physical and Clinical Aspects is a landmark publication, presenting a detailed account of the underlying physics, design, and implementation of the techniques, along with practical guidance for practitioners. Bridging the gap between research and application, this single source brings together the technological basis, radiation dosimetry, quality assurance, and fundamentals of brachytherapy. In addition, it presents discussion of the most recent clinical practice in brachytherapy including prostate, gynecology, breast, and other clinical treatment sites. Along with exploring new clinical protocols, ...

  10. Discrepancies in the half-lives of 90Sr, 137Cs and 252Cf

    International Nuclear Information System (INIS)

    Rajput, M.U.; Mac Mahon, T.D.

    1990-01-01

    Recent reports have pointed out that significant discrepancies exist in published half-life data for 90 Sr, 137 Cs and 252 Cr, amongst others. These discrepancies make the estimation of evaluated half-lives for these isotopes difficult and contentious. This paper reviews the current situation, takes into account recently available data and attempts to derive recommended half-lives and associated uncertainties for the three isotopes. 37 refs, 3 tabs

  11. Study of the 249-251Cf + 48Ca reactions: recent results and outlook

    Science.gov (United States)

    Voinov, A. A.; Oganessian, Yu Ts; Abdullin, F. Sh; Brewer, N. T.; Dmitriev, S. N.; Grzywacz, R. K.; Hamilton, J. H.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Rykaczewski, K. P.; Sabelnikov, A. V.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Stoyer, M. A.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu S.; Utyonkov, V. K.; Vostokin, G. K.

    2018-02-01

    Experiment aiming at the synthesis of heavy isotopes of Z=118 (Og) using beam of 48Ca and a target of 249-251Cf was undertaken in October 2015 - April 2016 employing the Dubna Gas-Filled Recoil Separator (FLNR JINR). The target of mixed isotopes of 249-251Cf (50.7% of 249Cf, 12.9% of 250Cf, and 36.4% of 251Cf) was irradiated by 48Ca ions at two beam energies of 252 and 258 MeV with the corresponding accumulated beam doses of 1.6×1019 and 1.1×1019. A single event observed at lower beam energy was assigned to the isotope 294Og, the product of the reaction 249Cf(48Ca, 3n); its decay pattern and the observed radioactive properties of the nuclides in the decay chain reproduce in full those observed for 294Og in our earlier experiments of 2002-2005 and 2012. At higher beam energy we observed no decay chains that could be attributed to the isotopes of Og. The possibility of renewal of this experiment in the future is discussed.

  12. Comparison of TG-43 and TG-186 in breast irradiation using a low energy electronic brachytherapy source

    International Nuclear Information System (INIS)

    White, Shane A.; Landry, Guillaume; Reniers, Brigitte; Fonseca, Gabriel Paiva; Holt, Randy; Rusch, Thomas; Beaulieu, Luc; Verhaegen, Frank

    2014-01-01

    Purpose: The recently updated guidelines for dosimetry in brachytherapy in TG-186 have recommended the use of model-based dosimetry calculations as a replacement for TG-43. TG-186 highlights shortcomings in the water-based approach in TG-43, particularly for low energy brachytherapy sources. The Xoft Axxent is a low energy ( w,m ) and dose to medium (D m,m ), for the heterogeneous simulations. All results were compared against TG-43-based dose distributions and evaluated using dose ratio maps and DVH metrics. Changes in skin and PTV dose were highlighted. Results: All simulated heterogeneous models showed a reduced dose to the DVH metrics that is dependent on the method of dose reporting and patient geometry. Based on a prescription dose of 34 Gy, the average D 90 to PTV was reduced by between ∼4% and ∼40%, depending on the scoring method, compared to the TG-43 result. Peak skin dose is also reduced by 10%–15% due to the absence of backscatter not accounted for in TG-43. The balloon applicator also contributed to the reduced dose. Other ROIs showed a difference depending on the method of dose reporting. Conclusions: TG-186-based calculations produce results that are different from TG-43 for the Axxent source. The differences depend strongly on the method of dose reporting. This study highlights the importance of backscatter to peak skin dose. Tissue heterogeneities, applicator, and patient geometries demonstrate the need for a more robust dose calculation method for low energy brachytherapy sources

  13. Automated absolute activation analysis with californium-252 sources

    International Nuclear Information System (INIS)

    MacMurdo, K.W.; Bowman, W.W.

    1978-09-01

    A 100-mg 252 Cf neutron activation analysis facility is used routinely at the Savannah River Laboratory for multielement analysis of many solid and liquid samples. An absolute analysis technique converts counting data directly to elemental concentration without the use of classical comparative standards and flux monitors. With the totally automated pneumatic sample transfer system, cyclic irradiation-decay-count regimes can be pre-selected for up to 40 samples, and samples can be analyzed with the facility unattended. An automatic data control system starts and stops a high-resolution gamma-ray spectrometer and/or a delayed-neutron detector; the system also stores data and controls output modes. Gamma ray data are reduced by three main programs in the IBM 360/195 computer: the 4096-channel spectrum and pertinent experimental timing, counting, and sample data are stored on magnetic tape; the spectrum is then reduced to a list of significant photopeak energies, integrated areas, and their associated statistical errors; and the third program assigns gamma ray photopeaks to the appropriate neutron activation product(s) by comparing photopeak energies to tabulated gamma ray energies. Photopeak areas are then converted to elemental concentration by using experimental timing and sample data, calculated elemental neutron capture rates, absolute detector efficiencies, and absolute spectroscopic decay data. Calculational procedures have been developed so that fissile material can be analyzed by cyclic neutron activation and delayed-neutron counting procedures. These calculations are based on a 6 half-life group model of delayed neutron emission; calculations include corrections for delayed neutron interference from 17 O. Detection sensitivities of 239 Pu were demonstrated with 15-g samples at a throughput of up to 140 per day. Over 40 elements can be detected at the sub-ppM level

  14. Measurement of the fission yields of selected prompt and decay fission product gamma-rays of spontaneously fissioning 252Cf and 244Cm

    International Nuclear Information System (INIS)

    Reber, E.L.; Gehrke, R.J.; Aryaeinejad, R.; Hartwell, J.K.

    2005-01-01

    Gamma-ray spectrometry measurements have been made of the fission yields of selected γ -rays emitted by the spontaneously fissioning isotopes 252 Cf and 244 Cm. The measured γ-rays were selected based on their relative abundance in the spectrum and their freedom from interference or, in a few instances, ease of interference correction. From these data and the cumulative and independent yield data of England and Rider, those γ-rays that are primarily produced by radioactive decay, as opposed to direct yield, were converted into the decays per spontaneous fission expressed in percent and compared to cumulative yield values of England and Rider. For those γ-rays whose production is dominated by direct (independent) yield, the ratio of γ-rays per spontaneous fission is reported. The γ-ray yield can be compared to the independent yield values of England and Rider when 100% of the direct feeding passes through the γ-ray. In those cases where both cumulative and independent yields contribute to the observed γ-ray emission rate, a direct comparison is not possible but a method to quantify the contribution from each is proposed. (author)

  15. Interstitial prostate brachytherapy. LDR-PDR-HDR

    International Nuclear Information System (INIS)

    Kovacs, Gyoergy; Hoskin, Peter

    2013-01-01

    The first comprehensive overview of interstitial brachytherapy for the management of local or locally advanced prostate cancer. Written by an interdisciplinary team who have been responsible for the successful GEC-ESTRO/EAU Teaching Course. Discusses in detail patient selection, the results of different methods, the role of imaging, and medical physics issues. Prostate brachytherapy has been the subject of heated debate among surgeons and the proponents of the various brachytherapy methods. This very first interdisciplinary book on the subject provides a comprehensive overview of innovations in low dose rate (LDR), high dose rate (HDR), and pulsed dose rate (PDR) interstitial brachytherapy for the management of local or locally advanced prostate cancer. In addition to detailed chapters on patient selection and the use of imaging in diagnostics, treatment guidance, and implantation control, background chapters are included on related medical physics issues such as treatment planning and quality assurance. The results obtained with the different treatment options and the difficult task of salvage treatment are fully discussed. All chapters have been written by internationally recognized experts in their fields who for more than a decade have formed the teaching staff responsible for the successful GEC-ESTRO/EAU Prostate Brachytherapy Teaching Course. This book will be invaluable in informing residents and others of the scientific background and potential of modern prostate brachytherapy. It will also prove a useful source of up-to-date information for those who specialize in prostate brachytherapy or intend to start an interstitial brachytherapy service.

  16. Definition of medical event is to be based on the total source strength for evaluation of permanent prostate brachytherapy: A report from the American Society for Radiation Oncology.

    Science.gov (United States)

    Nag, Subir; Demanes, D Jeffrey; Hagan, Michael; Rivard, Mark J; Thomadsen, Bruce R; Welsh, James S; Williamson, Jeffrey F

    2011-10-01

    The Nuclear Regulatory Commission deems it to be a medical event (ME) if the total dose delivered differs from the prescribed dose by 20% or more. A dose-based definition of ME is not appropriate for permanent prostate brachytherapy as it generates too many spurious MEs and thereby creates unnecessary apprehension in patients, and ties up regulatory bodies and the licensees in unnecessary and burdensome investigations. A more suitable definition of ME is required for permanent prostate brachytherapy. The American Society for Radiation Oncology (ASTRO) formed a working group of experienced clinicians to review the literature, assess the validity of current regulations, and make specific recommendations about the definition of an ME in permanent prostate brachytherapy. The working group found that the current definition of ME in §35.3045 as "the total dose delivered differs from the prescribed dose by 20 percent or more" was not suitable for permanent prostate brachytherapy since the prostate volume (and hence the resultant calculated prostate dose) is dependent on the timing of the imaging, the imaging modality used, the observer variability in prostate contouring, the planning margins used, inadequacies of brachytherapy treatment planning systems to calculate tissue doses, and seed migration within and outside the prostate. If a dose-based definition for permanent implants is applied strictly, many properly executed implants would be improperly classified as an ME leading to a detrimental effect on brachytherapy. The working group found that a source strength-based criterion, of >20% of source strength prescribed in the post-procedure written directive being implanted outside the planning target volume is more appropriate for defining ME in permanent prostate brachytherapy. ASTRO recommends that the definition of ME for permanent prostate brachytherapy should not be dose based but should be based upon the source strength (air-kerma strength) administered.

  17. WE-A-17A-02: BEST IN PHYSICS (THERAPY) - Development of a Calorimeter for the Measurement of the Power Emitted From LDR Brachytherapy Sources

    Energy Technology Data Exchange (ETDEWEB)

    Malin, M; Palmer, B; DeWerd, L [University of WI-Madison, Madison, WI (United States)

    2014-06-15

    Purpose: Model-based dose calculation algorithms for brachytherapy sources are designed to compute dose per particle or dose per unit energy leaving the encapsulation of a brachytherapy source. As such, the power leaving the encapsulation of a source, called emitted power (EP), would be a natural source strength metric for these new algorithms. However, no instrument is currently capable of an absolute measurement of EP. A calorimeter operating with a liquid helium thermal sink was designed and constructed to measure the EP of low-dose rate (LDR) I-125 and Pd-103 brachytherapy sources. Methods: Calorimeter design was optimized through thermal and Monte Carlo (MC) modeling. Thermal modeling showed that specific thermal conditions would be necessary for accurate calorimeter measurements. These conditions were experimentally verified. The EP of two LDR I-125 source models was measured. An air-kermastrength (AKS)-to-EP conversion coefficient was determined through MC simulations and applied to well-type ionization chamber measurements of AKS to enable comparison with EP measurements. Results: MCdetermined EP per unit AKS conversion coefficients were source model dependent and are on the order of 0.1 μW/U. The signal-to-noise ratio was a function of source strength, and was 294 for a 0.5 μW source. Measurements were repeatable to within 3.6% for a 0.5 μW source. Initial EP measurements were made with two I-125 source models, a 5.7 U Oncura 6711 and a 2.9 U Best Medical 2301. Model 2301 results agreed with the MC-converted AKS value to within the measurement uncertainty of 4.3% at k=1. The Model 6711 results were systematically high and are under investigation. Conclusion: A calorimeter was designed to provide an absolute measurement of the EP for LDR brachytherapy sources and preliminary EP measurements have been made. This new calorimeter design shows promise of providing a more fundamentally useful source strength standard.

  18. Investigation of source position uncertainties & balloon deformation in MammoSite brachytherapy on treatment effectiveness

    International Nuclear Information System (INIS)

    Bensaleh, S.

    2010-01-01

    The MammoSite ® breast high dose rate brachytherapy is used in treatment of early-stage breast cancer. The tumour bed volume is irradiated with high dose per fraction in a relatively small number of fractions. Uncertainties in the source positioning and MammoSite balloon deformation will alter the prescribed dose within the treated volume. They may also expose the normal tissues in balloon proximity to excessive dose. The purpose of this work is to explore the impact of these two uncertainties on the MammoSite dose distribution in the breast using dose volume histograms and Monte Carlo simulations. The Lyman–Kutcher and relative seriality models were employed to estimate the normal tissues complications associated with the MammoSite dose distributions. The tumour control probability was calculated using the Poisson model. This study gives low probabilities for developing heart and lung complications. The probability of complications of the skin and normal breast tissues depends on the location of the source inside the balloon and the volume receiving high dose. Incorrect source position and balloon deformation had significant effect on the prescribed dose within the treated volume. A 4 mm balloon deformation resulted in reduction of the tumour control probability by 24%. Monte Carlo calculations using EGSnrc showed that a deviation of the source by 1 mm caused approximately 7% dose reduction in the treated target volume at 1 cm from the balloon surface. In conclusion, accurate positioning of the 192 Ir source at the balloon centre and minimal balloon deformation are critical for proper dose delivery with the MammoSite brachytherapy applicator. On the basis of this study, we suggest that the MammoSite treatment protocols should allow for a balloon deformation of ≤2 mm and a maximum source deviation of ≤1 mm.

  19. Differential and integral comparisons of three representations of the prompt neutron spectrum for the spontaneous fission of 252Cf

    International Nuclear Information System (INIS)

    Madland, D.G.; LaBauve, R.J.; Nix, J.R.

    1984-01-01

    Because of their importance as neutron standards, we present comparisons of measured and calculated prompt fission neutron spectra N(E) and average prompt neutron multiplicities anti nu/sub p/ for the spontaneous fission of 252 Cf. In particular, we test three representations of N(E) against recent experimental measurements of the differential spectrum and threshold integral cross sections. These representations are the Maxwellian spectrum, the NBS spectrum, and the Los Alamos spectrum of Madland and Nix. For the Maxwellian spectrum, we obtain the value of the Maxwellian temperature T/sub M/ by a least-squares adjustment to the experimental differential spectrum of Poenitz and Tamura. For the Los Alamos spectrum, a similar least-squares adjustment determines the nuclear level-density parameter a, which is the single unknown parameter that appears. The NBS spectrum has been previously constructed by adjustments to eight differential spectra measured during the period 1965 to 1974. Among these three representations, we find that the Los Alamos spectrum best reproduces both the differential and integral measurements, assuming ENDF/B-V cross sections in the calculation of the latter. Although the NBS spectrum reproduces the integral measurements fairly well, it fails to satisfactorily reproduce the new differential measurement, and the Maxwellian spectrum fails to satisfactorily reproduce the integral measurements. Additionally, we calculate a value of anti nu/sub p/ from the Los Alamos theory that is within approximately 1% of experiment. 25 references

  20. Activation analysis of stainless steel flux monitors using 252Cf neutron sources

    International Nuclear Information System (INIS)

    Williams, J.G.; Newton, T.H. Jr.; Cogburn, C.O.

    1984-01-01

    Activation analysis was performed on stainless steel beads from a chain which is used in reactor pressure vessel surveillance experiments at the Arkansas Power and Light Company reactors. The beads allow monitoring of two fast and three thermal neutron induced reactions: 58 Ni(n,p) 58 Co, 54 Fe(n,p) 54 Mn, 58 Fe(n,γ) 59 Fe, 59 Co(n,γ) 60 Co and 50 Cr(n,γ) 51 Cr. The analysis was performed using 12 beads from various positions along 5 different batches of chain and standard materials in an H 2 O moderator tank using two intense californium sources which had a total neutron emission rate of 3.97 x 10 10 /s. Semiconductor gamma spectrometers were used to count the products of the above reactions in the specimens. The percentage by weight of the iron, chromium and cobalt in the beads were found to be 62.1%, 20.2% and 0.120%, respectively. The excellent uniformity found in the bead compositions demonstrates the reproducibility of the experimental techniques and enhances considerably the value of the beads as neutron flux montitors

  1. Dosimetry in high dose rate endoluminal brachytherapy

    International Nuclear Information System (INIS)

    Uno, Takashi; Kotaka, Kikuo; Itami, Jun

    1994-01-01

    In endoluminal brachytherapy for the tracheobronchial tree, esophagus, and bile duct, a reference point for dose calculation has been often settled at 1 cm outside from the middle of source travel path. In the current study, a change in the ratio of the reference point dose on the convex to concave side (Dq/Dp) was calculated, provided the source travel path bends as is the case in most endoluminal brachytherapies. Point source was presumed to move stepwise at 1 cm interval from 4 to 13 locations. Retention time at each location was calculated by personal computer so as to deliver equal dose at 1 cm from the linear travel path. With the retention time remaining constant, the change of Dq/Dp was assessed by bending the source travel path. Results indicated that the length of the source travel path and radius of its curve influenced the pattern of change in Dq/Dp. Therefore, it was concluded that the difference in reference dose on the convex and concave side of the curved path is not negligible under certain conditions in endoluminal brachytherapy. In order to maintain the ratio more than 0.9, relatively greater radius was required when the source travel path was decreased. (author)

  2. Transuranium processing plant report of production, status, and plans for the period October 1, 1978-September 30, 1980

    International Nuclear Information System (INIS)

    King, L.J.; Bigelow, J.E.; Collins, E.D.

    1981-08-01

    During this period, transuranium elements were obtained from 26 irradiated HFIT targets. The products included 86 mg of 249 Bk, 686 mg of 252 Cf, 3.1 mg of 253 Es, and an estimated 1.4 pg of 257 Fm. In addition, about 326 mg of high-purity 248 Cm was separated from previously purified 252 Cf. One hundred seven product shipments were made from TRU; recipients and the amounts of nuclides shipped are listed in a table. Forty-two standard and two special HFIR targets were fabricated. During the next 18 months, production totals of 110 mg of 249 Bk, 1200 mg of 252 Cf, 5.5 mg of 253 Es, and 2 pg of 257 Fm are anticipated. Also, a total of 225 mg of 248 Cm is expected to be made available. During this report period, a charcoal adsorber system for radioiodine removal was installed, tested, and placed in service. This system serves as a backup to the Hopcalite-charcoal system for adsorption of 131 I from the VOG stream. Seven 252 Cf neutron sources were fabricated during this report period. A total of 100 neutron sources have been fabricated previously at TRU. The original and current contents ( 252 Cf and 248 Cm) of the existing sources and the individuals to whom the sources are currently loaned are listed in a table. In addition to neutron sources, nine fission sources were prepared by electroplating 252 Cf onto platinum disks or foils.Special projects during this report period included (1) purification of two batches of isotopically pure 240 Pu, (2) fabrication of two special HFIR targets, (3) repurification of the residues of the einsteinium product from Campaign 56, (4) production of approx. 235 μg of 250 Cf by irradiation of 249 Bk, (5) radiography of 28 irradiated, stainless steel alloy, fracture-strain specimens, and (6) preparations for the production of 40 μg of 245 Es by irradiation of 253 Es

  3. Cluster pattern analysis of energy deposition sites for the brachytherapy sources 103Pd, 125I, 192Ir, 137Cs, and 60Co.

    Science.gov (United States)

    Villegas, Fernanda; Tilly, Nina; Bäckström, Gloria; Ahnesjö, Anders

    2014-09-21

    Analysing the pattern of energy depositions may help elucidate differences in the severity of radiation-induced DNA strand breakage for different radiation qualities. It is often claimed that energy deposition (ED) sites from photon radiation form a uniform random pattern, but there is indication of differences in RBE values among different photon sources used in brachytherapy. The aim of this work is to analyse the spatial patterns of EDs from 103Pd, 125I, 192Ir, 137Cs sources commonly used in brachytherapy and a 60Co source as a reference radiation. The results suggest that there is both a non-uniform and a uniform random component to the frequency distribution of distances to the nearest neighbour ED. The closest neighbouring EDs show high spatial correlation for all investigated radiation qualities, whilst the uniform random component dominates for neighbours with longer distances for the three higher mean photon energy sources (192Ir, 137Cs, and 60Co). The two lower energy photon emitters (103Pd and 125I) present a very small uniform random component. The ratio of frequencies of clusters with respect to 60Co differs up to 15% for the lower energy sources and less than 2% for the higher energy sources when the maximum distance between each pair of EDs is 2 nm. At distances relevant to DNA damage, cluster patterns can be differentiated between the lower and higher energy sources. This may be part of the explanation to the reported difference in RBE values with initial DSB yields as an endpoint for these brachytherapy sources.

  4. Application of TSH bioindicator for studying the biological efficiency of radiation

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Cebulska-Wasilewska, A.

    1996-10-01

    Dose response relationships for various endpoints (gene and lethal mutations, cell cycle alterations) in somatic cells of Tradescantia clone 4430 were established for X-rays and for mixed fast and thermal neutrons from Cf-252 source of KAERI and from U-120 cyclotron of INP. This was a pilot experiment to check if it is possible to establish the relative biological effectiveness values for Cf-252 irradiated TSH cells, with and without boron ion pretreatment, in conditions of mutual KAERI-INP experiment. When T-4430 was pretreated with boron ion, there was and enhancement in biological efficacy of neutron form Cf-252 source. 2 tabs., 7 figs., 7 refs. (Author)

  5. Evaluation of the response of polymeric gel modified MAGIC-f using a clinical brachytherapy source and Monte Carlo simulation with package PENELOPE

    International Nuclear Information System (INIS)

    Quevedo, Ana Luiza; Nicolucci, Patricia; Borges, Leandro F.

    2016-01-01

    In this work a comparison of experimental and simulated relative doses of a clinical brachytherapy source was performed. A 5 x 5 x 7 cm"3 phantom with a modified MAGIC-f gel was irradiated using a clinical "1"9"2Ir source and read using Magnetic Resonance Imaging. The Monte Carlo simulation package PENELOPE was used to simulate the dose distributions of the same radiation source. The dose distributions were obtained in two planes perpendicular to the source: one passing through the source's center and the other at 0.5 cm away from the source's center. The higher differences found between experimental and computational distributions were 12.5% at a point 0.62 cm from the source for the central plane and 8.6% at 1.3 cm from the source to the plane 0.5 cm away from the source's center. Considering the high dose gradient of these dose distributions, the results obtained show that the modified MAGIC-f gel is promising for brachytherapy dosimetry. (author)

  6. Fission-neutrons source with fast neutron-emission timing

    Energy Technology Data Exchange (ETDEWEB)

    Rusev, G., E-mail: rusev@lanl.gov; Baramsai, B.; Bond, E.M.; Jandel, M.

    2016-05-01

    A neutron source with fast timing has been built to help with detector-response measurements. The source is based on the neutron emission from the spontaneous fission of {sup 252}Cf. The time is provided by registering the fission fragments in a layer of a thin scintillation film with a signal rise time of 1 ns. The scintillation light output is measured by two silicon photomultipliers with rise time of 0.5 ns. Overall time resolution of the source is 0.3 ns. Design of the source and test measurements using it are described. An example application of the source for determining the neutron/gamma pulse-shape discrimination by a stilbene crystal is given.

  7. Evaluation of Wall Correction Factor of INER's Air-Kerma Primary Standard Chamber and Dose Variation by Source Displacement for HDR 192Ir Brachytherapy

    Directory of Open Access Journals (Sweden)

    J. H. Lee

    2013-01-01

    Full Text Available The aim of the present study was to estimate the wall effect of the self-made spherical graphite-walled cavity chamber with the Monte Carlo method for establishing the air-kerma primary standard of high-dose-rate (HDR 192Ir brachytherapy sources at the Institute of Nuclear Energy Research (INER, Taiwan. The Monte Carlo method established in this paper was also employed to respectively simulate wall correction factors of the 192Ir air-kerma standard chambers used at the National Institute of Standards and Technology (NIST, USA and the National Physical Laboratory (NPL, UK for comparisons and verification. The chamber wall correction calculation results will be incorporated into INER's HDR 192Ir primary standard in the future. For the brachytherapy treatment in the esophagus or in the bronchi, the position of the isotope may have displacement in the cavity. Thus the delivered dose would differ from the prescribed dose in the treatment plan. We also tried assessing dose distribution due to the position displacement of HDR 192Ir brachytherapy source in a phantom with a central cavity by the Monte Carlo method. The calculated results could offer a clinical reference for the brachytherapy within the human organs with cavity.

  8. Inverse gamma ray dose rate effect in californium-252 RBE experiment with human T-1 cells irradiated in vitro

    International Nuclear Information System (INIS)

    Todd, P.; Feola, J.M.

    1986-01-01

    Metabolically deoxygenated suspensions of human T-1 cells were used to determine the RBE in hypoxia of low dose rate (LDR) Cf-252 radiation compared to LDR gamma radiation. Based upon the initial portion of the survival curves the RBE was 5.0 ± 1.0 for all components of the Cf-252 radiation and 7.1 ± 1.7 for the neutrons alone. An inverse dose rate effect was observed for LDR gamma radiation in which greater cell sensitivity was observed at lower dose rates and longer irradiation periods. It was demonstrated that there was little or no sublethal damage repair or cell progression during LDR at 21 deg C, and the observed decrease in cell survival probability with increasing irradiation time at a given dose was attributable to reoxygenation of the cell suspensions during the course of LDR exposures. (Auth.)

  9. Investigation and optimisation of mobile NaI(Tl) and 3He-based neutron detectors for finding point sources

    International Nuclear Information System (INIS)

    Nilsson, Jonas M.C.; Finck, Robert R.; Rääf, Christopher

    2015-01-01

    Neutron radiation produces high-energy gamma radiation through (n,γ) reactions in matter. This can be used to detect neutron sources indirectly using gamma spectrometers. The sensitivity of a gamma spectrometer to neutrons can be amplified by surrounding it with polyvinyl chloride (PVC). The hydrogen in the PVC acts as a moderator and the chlorine emits prompt gammas when a neutron is captured. A 4.7-l 3 He-based mobile neutron detector was compared to a 4-l NaI(Tl)-detector covered with PVC using this principle. Methods were also developed to optimise the measurement parameters of the systems. The detector systems were compared with regard to their ability to find 241 AmBe, 252 Cf and 238 Pu– 13 C neutron sources. Results from stationary measurements were used to calculate optimal integration times as well as minimum detectable neutron emission rates. It was found that the 3 He-based detector was more sensitive to 252 Cf sources whereas the NaI(Tl) detector was more sensitive to 241 AmBe and 238 Pu– 13 C sources. The results also indicated that the sensitivity of the detectors to sources at known distances could theoretically be improved by 60% by changing from fixed integration times to list mode in mobile surveys

  10. Basic experiment on scattering type level gauge using neutron source

    International Nuclear Information System (INIS)

    Kumazaki, Hiroshi; Fukuchi, Ryoichi; Horiguchi, Yasuhiro

    1984-01-01

    The level gauges using sealed radiation sources have been utilized for pulp and chemical industries, however, for those gauges, transmission type gamma sources are used, which require considerably large radioactivity, and it hinders the spread to medium and small enterprises. Recently, Cf-252 has become easily available, and various He-3 counters are on the market, consequently, the scattering type level gauges combining them have been examined. With the level gauges of this type, the judgement of level can be made sufficiently with the Cf-252 below 3.7 x 10 6 Bq, therefore, if the practical instruments are made, they seem to spread into medium and small enterprises because of the safety and the chief handling radiation being unnecessary. For the purpose of developing and manufacturing for trial this scattering type level gauge, the basic experiment was carried out to examine the effects of the change of salt content and the thickness of vessels and the effect of scattering materials. The possibility of the on-off operation as level gauges was also examined. The experimental method and the results are reported. The count considerably decreased with increasing salt content. Scattering materials worked effectively to increase the count. (Kako, I.)

  11. Pulsed dose rate brachytherapy – is it the right way?

    Directory of Open Access Journals (Sweden)

    Janusz Skowronek

    2010-10-01

    Full Text Available Pulsed dose rate (PDR-BT treatment is a brachytherapy modality that combines physical advantages of high-doserate (HDR-BT technology (isodose optimization, radiation safety with the radiobiological advantages of low-dose-rate (LDR-BT brachytherapy. Pulsed brachytherapy consists of using stronger radiation source than for LDR-BT and producing series of short exposures of 10 to 30 minutes in every hour to approximately the same total dose in the sameoverall time as with the LDR-BT. Modern afterloading equipment offers certain advantages over interstitial or intracavitaryinsertion of separate needles, tubes, seeds or wires. Isodose volumes in tissues can be created flexibly by a combinationof careful placement of the catheter and the adjustment of the dwell times of the computerized stepping source.Automatic removal of the radiation sources into a shielded safe eliminates radiation exposures to staff and visitors.Radiation exposure is also eliminated to the staff who formerly loaded and unloaded multiplicity of radioactive sources into the catheters, ovoids, tubes etc. This review based on summarized clinical investigations, analyses the feasibility and the background to introduce this brachytherapy technique and chosen clinical applications of PDR-BT.

  12. Design and optimization of a brachytherapy robot

    Science.gov (United States)

    Meltsner, Michael A.

    Trans-rectal ultrasound guided (TRUS) low dose rate (LDR) interstitial brachytherapy has become a popular procedure for the treatment of prostate cancer, the most common type of non-skin cancer among men. The current TRUS technique of LDR implantation may result in less than ideal coverage of the tumor with increased risk of negative response such as rectal toxicity and urinary retention. This technique is limited by the skill of the physician performing the implant, the accuracy of needle localization, and the inherent weaknesses of the procedure itself. The treatment may require 100 or more sources and 25 needles, compounding the inaccuracy of the needle localization procedure. A robot designed for prostate brachytherapy may increase the accuracy of needle placement while minimizing the effect of physician technique in the TRUS procedure. Furthermore, a robot may improve associated toxicities by utilizing angled insertions and freeing implantations from constraints applied by the 0.5 cm-spaced template used in the TRUS method. Within our group, Lin et al. have designed a new type of LDR source. The "directional" source is a seed designed to be partially shielded. Thus, a directional, or anisotropic, source does not emit radiation in all directions. The source can be oriented to irradiate cancerous tissues while sparing normal ones. This type of source necessitates a new, highly accurate method for localization in 6 degrees of freedom. A robot is the best way to accomplish this task accurately. The following presentation of work describes the invention and optimization of a new prostate brachytherapy robot that fulfills these goals. Furthermore, some research has been dedicated to the use of the robot to perform needle insertion tasks (brachytherapy, biopsy, RF ablation, etc.) in nearly any other soft tissue in the body. This can be accomplished with the robot combined with automatic, magnetic tracking.

  13. Biology of dose rate in brachytherapy

    International Nuclear Information System (INIS)

    Brenner, David J.

    1995-01-01

    Purpose: This course is designed for practitioners and beginners in brachytherapy. The aim is to review biological principles underlying brachytherapy, to understand why current treatment regimes are the way they are, and to discuss what the future may hold in store. Brachytherapy has a long history. It was suggested as long ago as 1903 by Alexander Graham Bell, and the optimal application of this technique has been a subject of debate ever since. 'Brachy' means 'short', and the essential features of conventional brachytherapy are: positioning of the source a short distance from, or in, the tumor, allowing good dose distributions; short overall treatment times, to counter tumor repopulation; low dose rate, enabling a good therapeutic advantage between tumor control and damage to late-responding tissue. The advantages of good dose distributions speak for themselves; in some situations, as we shall see, computer-based dose optimization can be used to improve them still further. The advantages of short overall times stem from the fact that accelerated repopulation of the tumor typically begins a few weeks after the start of a radiation treatment. If all the radiation can be crammed in before that time, the risks of tumor repopulation can be considerably reduced. In fact even external-beam radiotherapy is moving in this direction, with the use of highly accelerated protocols. The advantages of low dose rate stem from the differential response to fractionation of early- and late-responding tissues. Essentially, lowering the dose rate spares late-responding tissue more than it does early-responding tissue such as tumors. We shall also discuss some recent innovations in the context of the general principles that have been outlined. For example, High dose rate brachytherapy, particularly for the uterine cervix: Does it work? If so, when and why? Use of Ir-192 sources, with a half life of 70 days: Should corrections be made for changing biological effectiveness as the dose

  14. Radiological protection on interstitial brachytherapy and dose determination and exposure rate of an Ir-192 source through the MCNP-4B

    International Nuclear Information System (INIS)

    Morales L, M.E.

    2006-01-01

    The present work was carried out in the Neurological Sciences Institute having as objective to determine the dose and the rate of exhibition of the sources of Iridium 192, Iodine 125 and Palladium 103; which are used to carry out implant in the Interstitial Brachytherapy according to the TG43. For it we carry out a theoretical calculation, its are defined in the enter file: the geometry, materials of the problem and the radiation source, etc; in the MCNP-4B Monte Carlo code, considering a punctual source and for the dose determination we simulate thermoluminescent dosemeters (TLD): at 5 cm, 50 cm, 100 cm and 200 cm of the source. Our purpose is to analyze the radioprotection measures that should take into account in this Institute in which are carried out brain biopsies using a Micro mar stereotactic mark, and in a near future with the collaboration of a doctor and a cuban physique seeks to be carried out the Interstitial Brachytherapy technique with sources of Ir-192 for patient with tumors like glioblastoma, astrocytoma, etc. (Author)

  15. American College of Radiology-American Brachytherapy Society practice parameter for electronically generated low-energy radiation sources.

    Science.gov (United States)

    Devlin, Phillip M; Gaspar, Laurie E; Buzurovic, Ivan; Demanes, D Jeffrey; Kasper, Michael E; Nag, Subir; Ouhib, Zoubir; Petit, Joshua H; Rosenthal, Seth A; Small, William; Wallner, Paul E; Hartford, Alan C

    This collaborative practice parameter technical standard has been created between the American College of Radiology and American Brachytherapy Society to guide the usage of electronically generated low energy radiation sources (ELSs). It refers to the use of electronic X-ray sources with peak voltages up to 120 kVp to deliver therapeutic radiation therapy. The parameter provides a guideline for utilizing ELS, including patient selection and consent, treatment planning, and delivery processes. The parameter reviews the published clinical data with regard to ELS results in skin, breast, and other cancers. This technical standard recommends appropriate qualifications of the involved personnel. The parameter reviews the technical issues relating to equipment specifications as well as patient and personnel safety. Regarding suggestions for educational programs with regard to this parameter,it is suggested that the training level for clinicians be equivalent to that for other radiation therapies. It also suggests that ELS must be done using the same standards of quality and safety as those in place for other forms of radiation therapy. Copyright © 2017 American Brachytherapy Society and American College of Radiology. Published by Elsevier Inc. All rights reserved.

  16. Comparison of TG-43 dosimetric parameters of brachytherapy sources obtained by three different versions of MCNP codes.

    Science.gov (United States)

    Zaker, Neda; Zehtabian, Mehdi; Sina, Sedigheh; Koontz, Craig; Meigooni, Ali S

    2016-03-08

    Monte Carlo simulations are widely used for calculation of the dosimetric parameters of brachytherapy sources. MCNP4C2, MCNP5, MCNPX, EGS4, EGSnrc, PTRAN, and GEANT4 are among the most commonly used codes in this field. Each of these codes utilizes a cross-sectional library for the purpose of simulating different elements and materials with complex chemical compositions. The accuracies of the final outcomes of these simulations are very sensitive to the accuracies of the cross-sectional libraries. Several investigators have shown that inaccuracies of some of the cross section files have led to errors in 125I and 103Pd parameters. The purpose of this study is to compare the dosimetric parameters of sample brachytherapy sources, calculated with three different versions of the MCNP code - MCNP4C, MCNP5, and MCNPX. In these simulations for each source type, the source and phantom geometries, as well as the number of the photons, were kept identical, thus eliminating the possible uncertainties. The results of these investigations indicate that for low-energy sources such as 125I and 103Pd there are discrepancies in gL(r) values. Discrepancies up to 21.7% and 28% are observed between MCNP4C and other codes at a distance of 6 cm for 103Pd and 10 cm for 125I from the source, respectively. However, for higher energy sources, the discrepancies in gL(r) values are less than 1.1% for 192Ir and less than 1.2% for 137Cs between the three codes.

  17. Studies on the preparation of 103Pd inner core of seed sources for brachytherapy applications

    International Nuclear Information System (INIS)

    Saha, Sujata; Manolkar, R.B.; Vimalnath, K.V.; Dash, A.; Venkatesh, Meera

    2007-01-01

    103 Pd seed sources are used widely world over for brachytherapy applications. 103 Pd available in-house was used to study its deposition on silver wire using electro-deposition and electroless deposition techniques with an aim to developing the inner core preparation of sealed radiation sources for treatment of prostate and ocular melanoma. Various parameters such as radioactive concentration of the feed solution, current density, time, temperature and pH of the solution were optimized to achieve maximum 103 Pd deposition on Ag wire. In electroless technique, the deposited amount of Pd was found to be nearly triple compared to electro-deposition in two hours time period. Both the methods gave nonleachable and well adherent sources. (author)

  18. Brachytherapy source calibration, reviews, and consistency of 192Ir high-dose rate afterloading sources supplied over the period of 10 years: a retrospective analysis

    International Nuclear Information System (INIS)

    Nagappan, Balasubramanian; Kumar, Yogesh; Patel, Narayan P.; Dhull, Anil Kumar; Kaushal, Vivek

    2015-01-01

    Measurement and verification of strength of monomodal high-dose rate (mHDR) 192 Ir source supplied by the vendor is a major part of quality assurance program. Reference air kerma rate (RAKR) or air kerma strength (AKS) is the recommended quantity to specify the strength of gamma emitting brachytherapy sources. Physicist in our institution performed the source calibration as soon as each 192 Ir new source was loaded on the mHDR afterloading machine. The AKS accurately measured using a physikalisch technische werkstatten (PTW) re-entrant chamber-electrometer system in a scatter-free geometry was used to compute the air kerma rate (AKR) at one-meter distance in the air. To ensure accurate dose delivery to brachytherapy patients, measured AKS or RAKR should be entered correctly in both HDR treatment console station (TCS) as well as treatment planning system (TPS) associated with it. The clinical outcome mainly depends not only on the accuracy of the source strength measurement in the hospital but also on the correct source strength entered into both TCS and TPS software. A retrospective study on 22 mHDR V2 sources supplied by the vendor for the period of 10 years was taken up to access the accuracy of source strength supplied to the Radiotherapy department. The results are analyzed and reported. The accuracy in measured RAKR of all 22 sources supplied by vendor was well within the tolerance limits set by the national regulatory body and international recommendations. The deviations observed between measured RAKR versus manufacturer's quoted RAKR were in the range from -1.71% to +1.15%. In conclusion, the measured RAKR have good agreement with vendor quoted RAKR values. (author)

  19. Transport calculations of. gamma. -ray flux density and dose rate about implantable californium-252 sources

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, A; Lin, B I [Cincinnati Univ., Ohio (USA). Dept. of Chemical and Nuclear Engineering; Windham, J P; Kereiakes, J G

    1976-07-01

    ..gamma.. flux density and dose rate distributions have been calculated about implantable californium-252 sources for an infinite tissue medium. Point source flux densities as a function of energy and position were obtained from a discrete-ordinates calculation, and the flux densities were multiplied by their corresponding kerma factors and added to obtain point source dose rates. The point dose rates were integrated over the line source to obtain line dose rates. Container attenuation was accounted for by evaluating the point dose rate as a function of platinum thickness. Both primary and secondary flux densities and dose rates are presented. The agreement with an independent Monte Carlo calculation was excellent. The data presented should be useful for the design of new source configurations.

  20. Comparison of TG-43 and TG-186 in breast irradiation using a low energy electronic brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    White, Shane A.; Landry, Guillaume; Reniers, Brigitte, E-mail: brigitte.reniers@maastro.nl [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN (Netherlands); Fonseca, Gabriel Paiva [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Instituto de Pesquisas Energéticas e Nucleares – IPEN-CNEN/SP, São Paulo CP 11049, 05422-970 (Brazil); Holt, Randy; Rusch, Thomas [Xoft, A Subsidiary of iCAD, Sunnyvale, California 94085-4115 (United States); Beaulieu, Luc [Centre Hospitalier Universitaire de Québec Université Laval, Radio-Oncologie et Centre de Recherche en Cancérologie de l’Université Laval, Québec, Québec G1R 2J6 Canada (Canada); Verhaegen, Frank [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Department of Oncology, McGill University, Montreal, Quebec H3G 1A4 (Canada)

    2014-06-15

    Purpose: The recently updated guidelines for dosimetry in brachytherapy in TG-186 have recommended the use of model-based dosimetry calculations as a replacement for TG-43. TG-186 highlights shortcomings in the water-based approach in TG-43, particularly for low energy brachytherapy sources. The Xoft Axxent is a low energy (<50 kV) brachytherapy system used in accelerated partial breast irradiation (APBI). Breast tissue is a heterogeneous tissue in terms of density and composition. Dosimetric calculations of seven APBI patients treated with Axxent were made using a model-based Monte Carlo platform for a number of tissue models and dose reporting methods and compared to TG-43 based plans. Methods: A model of the Axxent source, the S700, was created and validated against experimental data. CT scans of the patients were used to create realistic multi-tissue/heterogeneous models with breast tissue segmented using a published technique. Alternative water models were used to isolate the influence of tissue heterogeneity and backscatter on the dose distribution. Dose calculations were performed using Geant4 according to the original treatment parameters. The effect of the Axxent balloon applicator used in APBI which could not be modeled in the CT-based model, was modeled using a novel technique that utilizes CAD-based geometries. These techniques were validated experimentally. Results were calculated using two dose reporting methods, dose to water (D{sub w,m}) and dose to medium (D{sub m,m}), for the heterogeneous simulations. All results were compared against TG-43-based dose distributions and evaluated using dose ratio maps and DVH metrics. Changes in skin and PTV dose were highlighted. Results: All simulated heterogeneous models showed a reduced dose to the DVH metrics that is dependent on the method of dose reporting and patient geometry. Based on a prescription dose of 34 Gy, the average D{sub 90} to PTV was reduced by between ∼4% and ∼40%, depending on the

  1. Determination of dosimetric characteristics of OptiSeedTM a plastic brachytherapy 103Pd source

    International Nuclear Information System (INIS)

    Wang Zhonglu; Hertel, Nolan E.

    2005-01-01

    A new 103 Pd plastic brachytherapy source, OptiSeed TM Model 1032P, is being introduced by International Brachytherapy sa (IBt). Measurements of the dose distributions about the source were performed using LiF thermoluminescent dosimeters (TLD-100) in Virtual Water TM . MCNP5 calculations were performed to determine the dose distributions in Virtual Water TM and liquid water. The source dose rate constant, radial dose function, anisotropy function and anisotropy factor have been determined following the updated AAPM TG-43 recommendations. The measured dose rate constant in the Virtual Water TM phantom was determined to be 0.727±6.9% cGy h -1 U -1 , and the computed value is 0.716±2.1% cGy h -1 U -1 . The Monte-Carlo simulation yielded a dose rate constant of 0.665±2.1% cGy h -1 U -1 in water. The measured dose rate constant in water is 0.675±7.5% cGy h -1 U -1 . It is determined by multiplying the dose rate constant measured in the Virtual Water TM phantom with the ratio of the value calculated in water to that in Virtual Water TM . The average of the measured and calculated dose rate constant is 0.670±5.5% cGy h -1 U -1 . The radial dose functions of the new source were measured for distances ranging from 1 to 7 cm in a Virtual Water TM phantom. The anisotropy functions in Virtual Water TM phantom were measured for distances of 2, 3, 5, and 7 cm. The Monte-Carlo computed radial dose functions, anisotropy functions, and anisotropy factors in both Virtual Water TM phantom and water are reported

  2. Calibration of {sup 192}Ir high dose rate brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Marechal, M H [Instituto de Radioprotecao e Dozimetria, Rio de Jainero (Brazil); Almeida, C.E. de [Laboratorio de Ciencias Radiologicas, UERL, Rio de Janeiro (Brazil); Sibata, C H [Roswell Park Cancer Inst., Buffalo, NY (United States)

    1996-08-01

    A method for calibration of high dose rate sources used in afterloading brachytherapy systems is described. The calibration for {sup 192}Ir is determined by interpolating {sup 60}Co gamma-rays and 250 kV x-rays calibration factors. All measurements were done using the same build up caps as described by Goetsch et al and recommended by AAPM. The attenuation correction factors were determined to be 0.9903, 0.9928 and 0.9993 for {sup 192}Ir, {sup 60}Co and 250 kV x-ray, respectively. A wall + cap thickness of 0.421 g.cm{sup -2} is recommended for all measurements to ensure electronic equilibrium for {sup 60}Co and {sup 192}Ir gamma-ray beams. A mathematical formalism is described for determination of (N{sub x}){sub Ir}. (author). 5 refs, 1 fig.

  3. Design and dosimetric characteristics of a new endocavitary contact radiotherapy system using an electronic brachytherapy source.

    Science.gov (United States)

    Richardson, Susan; Garcia-Ramirez, Jose; Lu, Wei; Myerson, Robert J; Parikh, Parag

    2012-11-01

    To present design aspects and acceptance tests performed for clinical implementation of electronic brachytherapy treatment of early stage rectal adenocarcinoma. A dosimetric comparison is made between the historically used Philips RT-50 unit and the newly developed Axxent(®) Model S700 electronic brachytherapy source manufactured by Xoft (iCad, Inc.). Two proctoscope cones were manufactured by ElectroSurgical Instruments (ESI). Two custom surface applicators were manufactured by Xoft and were designed to fit and interlock with the proctoscope cones from ESI. Dose rates, half value layers (HVL), and percentage depth dose (PDD) measurements were made with the Xoft system and compared to historical RT-50 data. A description of the patient treatment approach and exposure rates during the procedure is also provided. The electronic brachytherapy system has a lower surface dose rate than the RT-50. The dose rate to water on the surface from the Xoft system is approximately 2.1 Gy∕min while the RT-50 is 10-12 Gy∕min. However, treatment times with Xoft are still reasonable. The HVLs and PDDs between the two systems were comparable resulting in similar doses to the target and to regions beyond the target. The exposure rate levels around a patient treatment were acceptable. The standard uncertainty in the dose rate to water on the surface is approximately ±5.2%. The Philips RT-50 unit is an out-of-date radiotherapy machine that is no longer manufactured with limited replacement parts. The use of a custom-designed proctoscope and Xoft surface applicators allows delivery of a well-established treatment with the ease of a modern radiotherapy device. While the dose rate is lower with the use of Xoft, the treatment times are still reasonable. Additionally, personnel may stand farther away from the Xoft radiation source, thus potentially reducing radiation exposure to the operator and other personnel.

  4. Comparison of TG‐43 dosimetric parameters of brachytherapy sources obtained by three different versions of MCNP codes

    Science.gov (United States)

    Zaker, Neda; Sina, Sedigheh; Koontz, Craig; Meigooni1, Ali S.

    2016-01-01

    Monte Carlo simulations are widely used for calculation of the dosimetric parameters of brachytherapy sources. MCNP4C2, MCNP5, MCNPX, EGS4, EGSnrc, PTRAN, and GEANT4 are among the most commonly used codes in this field. Each of these codes utilizes a cross‐sectional library for the purpose of simulating different elements and materials with complex chemical compositions. The accuracies of the final outcomes of these simulations are very sensitive to the accuracies of the cross‐sectional libraries. Several investigators have shown that inaccuracies of some of the cross section files have led to errors in  125I and  103Pd parameters. The purpose of this study is to compare the dosimetric parameters of sample brachytherapy sources, calculated with three different versions of the MCNP code — MCNP4C, MCNP5, and MCNPX. In these simulations for each source type, the source and phantom geometries, as well as the number of the photons, were kept identical, thus eliminating the possible uncertainties. The results of these investigations indicate that for low‐energy sources such as  125I and  103Pd there are discrepancies in gL(r) values. Discrepancies up to 21.7% and 28% are observed between MCNP4C and other codes at a distance of 6 cm for  103Pd and 10 cm for  125I from the source, respectively. However, for higher energy sources, the discrepancies in gL(r) values are less than 1.1% for  192Ir and less than 1.2% for  137Cs between the three codes. PACS number(s): 87.56.bg PMID:27074460

  5. Enhancement of discharge performance of Li/CF x cell by thermal treatment of CF x cathode material

    Science.gov (United States)

    Zhang, Sheng S.; Foster, Donald; Read, Jeffrey

    In this work we demonstrate that the thermal treatment of CF x cathode material just below the decomposition temperature can enhance discharge performance of Li/CF x cells. The performance enhancement becomes more effective when heating a mixture of CF x and citric acid (CA) since CA serves as an extra carbon source. Discharge experiments show that the thermal treatment not only reduces initial voltage delay, but also raises discharge voltage. Whereas the measurement of powder impedance indicates the thermal treatment does not increase electronic conductivity of CF x material. Based on these facts, we propose that the thermal treatment results in a limited decomposition of CF x, which yields a subfluorinated carbon (CF x- δ), instead of a highly conductive carbon. In the case of CF x/AC mixture, the AC provides extra carbon that reacts with F 2 and fluorocarbon radicals generated by the thermal decomposition of CF x to form subfluorinated carbon. The process of thermal treatment is studied by thermogravimetric analysis and X-ray diffraction, and the effect of treatment conditions such as heating temperature, heating time and CF x/CA ratio on the discharge performance of CF x cathode is discussed. As an example, a Li/CF x cell using CF x treated with CA at 500 °C under nitrogen for 2 h achieved theretical specific capacity when being discharged at C/5. Impedance analysis indicates that the enhanced performance is attributed to a significant reduction in the cell reaction resistance.

  6. MO-D-BRD-03: Radiobiology and Commissioning of Electronic Brachytherapy for IORT

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J. [Oregon Health & Science Univ (United States)

    2015-06-15

    Electronic brachytherapy (eBT) has seen an insurgence of manufacturers entering the US market for use in radiation therapy. In addition to the established interstitial, intraluminary, and intracavitary applications of eBT, many centers are now using eBT to treat skin lesions. It is important for medical physicists working with electronic brachytherapy sources to understand the basic physics principles of the sources themselves as well as the variety of applications for which they are being used. The calibration of the sources is different from vendor to vendor and the traceability of calibrations has evolved as new sources came to market. In 2014, a new air-kerma based standard was introduced by the National Institute of Standards and Technology (NIST) to measure the output of an eBT source. Eventually commercial treatment planning systems should accommodate this new standard and provide NIST traceability to the end user. The calibration and commissioning of an eBT system is unique to its application and typically entails a list of procedural recommendations by the manufacturer. Commissioning measurements are performed using a variety of methods, some of which are modifications of existing AAPM Task Group protocols. A medical physicist should be familiar with the different AAPM Task Group recommendations for applicability to eBT and how to properly adapt them to their needs. In addition to the physical characteristics of an eBT source, the photon energy is substantially lower than from HDR Ir-192 sources. Consequently, tissue-specific dosimetry and radiobiological considerations are necessary when comparing these brachytherapy modalities and when making clinical decisions as a radiation therapy team. In this session, the physical characteristics and calibration methodologies of eBt sources will be presented as well as radiobiology considerations and other important clinical considerations. Learning Objectives: To understand the basic principles of electronic

  7. Source storage and transfer cask: Users Guide

    International Nuclear Information System (INIS)

    Eccleston, G.W.; Speir, L.G.; Garcia, D.C.

    1985-04-01

    The storage and shield cask for the dual californium source is designed to shield and transport up to 3.7 mg (2 Ci) of 252 Cf. the cask meets Department of Transportation (DOT) license requirements for Type A materials (DOT-7A). The cask is designed to transfer sources to and from the Flourinel and Fuel Storage (FAST) facility delayed-neutron interrogator. Californium sources placed in the cask must be encapsulated in the SR-CF-100 package and attached to Teleflex cables. The cask contains two source locations. Each location contains a gear box that allows a Teleflex cable to be remotely moved by a hand crank into and out of the cask. This transfer procedure permits sources to be easily removed and inserted into the delayed-neutron interrogator and reduces personnel radiation exposure during transfer. The radiation dose rate with the maximum allowable quantity of californium (3.7 mg) in the cask is 30 mR/h at the surface and less than 2 mR/h 1 m from the cask surface. This manual contains information about the cask, californium sources, describes the method to ship the cask, and how to insert and remove sources from the cask. 28 figs

  8. Brachytherapy with 125-Iodine sources: transport and radiation protection

    International Nuclear Information System (INIS)

    Souza, Carla D.; Zeituni, Carlos A.; Moura, Joao A.; Moura, Eduardo S.; Nagatomi, Helio R.; Feher, Anselmo; Hilario, Katia F.; Rostelato, Maria Elisa C.M.

    2009-01-01

    The estimates for the year 2009 show that 466,730 new cancer cases will occur in Brazil. Prostate cancer is the second most incident type. Brachytherapy, a type of radiotherapy, with Iodine-125 sources are an important form of treatment for this kind of cancer. The Instituto de Pesquisas Energeticas e Nucleares (IPEN) created a project to develop a national prototype of these sources and is implementing a facility for local production. The seeds manufacture in Brazil will allow to diminish the treatment cost and make it possible for a larger number of patients. While the laboratory is not ready, the IPEN import and it distributes seeds. This work aim is to present and evaluate the transport procedures and the radiological protection applied to imported sources in order to assist the procedures for the new laboratory implementation. Before sending to hospitals, the seeds are packed by a radioprotector supervisor, in accordance with CNEN NE 5.01 standard 'Radioactive Material Transport'. Despite Iodine-125 presents low energy photons, around 29 keV, local and personal dosimeters are used during the transport process, as described in CNEN NN 3.01 standard 'Radiological Protection Basic Guideline'. All the results show no contamination and very low exposure, proving the method to be valid. The transport procedure used is correct, according to the regulations. As an result of this work, a new dosimeter should be installed and evaluate in future study. (author)

  9. Dose heterogeneity correction for low-energy brachytherapy sources using dual-energy CT images

    Science.gov (United States)

    Mashouf, S.; Lechtman, E.; Lai, P.; Keller, B. M.; Karotki, A.; Beachey, D. J.; Pignol, J. P.

    2014-09-01

    Permanent seed implant brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose around brachytherapy sources is based on the AAPM TG-43 formalism, which generates the dose in a homogeneous water medium. Recently, AAPM TG-186 emphasized the importance of accounting for tissue heterogeneities. We have previously reported on a methodology where the absorbed dose in tissue can be obtained by multiplying the dose, calculated by the TG-43 formalism, by an inhomogeneity correction factor (ICF). In this work we make use of dual energy CT (DECT) images to extract ICF parameters. The advantage of DECT over conventional CT is that it eliminates the need for tissue segmentation as well as assignment of population based atomic compositions. DECT images of a heterogeneous phantom were acquired and the dose was calculated using both TG-43 and TG-43 × \\text{ICF} formalisms. The results were compared to experimental measurements using Gafchromic films in the mid-plane of the phantom. For a seed implant configuration of 8 seeds spaced 1.5 cm apart in a cubic structure, the gamma passing score for 2%/2 mm criteria improved from 40.8% to 90.5% when ICF was applied to TG-43 dose distributions.

  10. Neutron dosimetry at SLAC: Neutron sources and instrumentation

    International Nuclear Information System (INIS)

    Liu, J.C.; Jenkins, T.M.; McCall, R.C.; Ipe, N.E.

    1991-10-01

    This report summarizes in detail the dosimetric characteristics of the five radioisotopic type neutron sources ( 238 PuBe, 252 Cf, 238 PuB, 238 PuF 4 , and 238 PuLi) and the neutron instrumentation (moderated BF 3 detector, Anderson-Braun (AB) detector, AB remmeter, Victoreen 488 Neutron Survey Meter, Beam Shut-Off Ionization Chamber, 12 C plastic scintillator detector, moderated indium foil detector, and moderated and bare TLDs) that are commonly used for neutron dosimetry at the Stanford Linear Accelerator Center (SLAC). 36 refs,. 19 figs

  11. Separation of fission produced 106Ru from simulated high level nuclear wastes for production of brachytherapy sources

    International Nuclear Information System (INIS)

    Blicharska, Magdalena; Bartoś, Barbara; Krajewski, Seweryn; Bilewicz, Aleksander

    2014-01-01

    Brachytherapy is the common method for treating various tumors, and currently 106 Ru and 125 I applicators are the most frequently used. Considering that 106 Ru is a β emitter with maximum energy of 3.54 MeV, it is best indicated in the treatment of small melanomas, with up to 20 mm tissue range. 106 Ru is commercially obtained from neutron irradiated high enrichment 235 U target in process of production 99 Mo. At present, there are only a handful of ageing reactors worldwide capable of producing the 99 Mo, therefore alternative strategies for production of this key medical isotope are explored. In our work, we propose to use liquid high-level radioactive waste as a source of high activity of 106 Ru. Simple calculations indicate that 1 dm 3 of HLLW solution after 4 years of cooling contains about 500 GBq of 106 Ru. This amount of activity is enough for production of about few thousands of brachytherapy sources. Present communication reports results of our process development studies on the recovery of ruthenium radioisotopes from simulated solution of high level radioactive waste using oxidation-extraction method

  12. Determination of the chemical yield on the Fricke dosimetry for 192Ir sources used in brachytherapy

    International Nuclear Information System (INIS)

    David, M.G.; Albuquerque, M.A.G.; Almeida, C.E. de; Rosado, P.H.

    2015-01-01

    With the aim of developing a primary standard for the absorbed dose to water, for the 192 Ir sources used in high dose rate brachytherapy, this work focuses on the determination of the chemical yield, G(Fe +3 ), using Fricke dosimetry, for the energy of those sources . The G(Fe +3 ) were determined the for three qualities of x-ray beams (150, 250 and 300 kV ) and for 60 Co energy. The G(Fe +3 ) value for the average energy of 192 Ir was obtained by linear fit, the found value was 1,555 ± 0,015 μmol/J. (author)

  13. Source of hope [El Salvador’s only brachytherapy centre

    International Nuclear Information System (INIS)

    Falcon Castro, Nancy

    2010-01-01

    Set up in 2008 with the IAEA’s support, the Cancer Institute 'Dr. Narciso Diaz Bazan' is El Salvador’s only brachytherapy treatment facility for women affected by uterine cancer. To date, over 1000 women affected by cervical cancer have received treatment in the centre

  14. SU-F-T-32: Evaluation of the Performance of a Multiple-Array-Diode Detector for Quality Assurance Tests in High-Dose-Rate Brachytherapy with Ir-192 Source

    Energy Technology Data Exchange (ETDEWEB)

    Harpool, K; De La Fuente Herman, T; Ahmad, S; Ali, I [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2016-06-15

    Purpose: To evaluate the performance of a two-dimensional (2D) array-diode- detector for geometric and dosimetric quality assurance (QA) tests of high-dose-rate (HDR) brachytherapy with an Ir-192-source. Methods: A phantom setup was designed that encapsulated a two-dimensional (2D) array-diode-detector (MapCheck2) and a catheter for the HDR brachytherapy Ir-192 source. This setup was used to perform both geometric and dosimetric quality assurance for the HDR-Ir192 source. The geometric tests included: (a) measurement of the position of the source and (b) spacing between different dwell positions. The dosimteric tests include: (a) linearity of output with time, (b) end effect and (c) relative dose verification. The 2D-dose distribution measured with MapCheck2 was used to perform the previous tests. The results of MapCheck2 were compared with the corresponding quality assurance testes performed with Gafchromic-film and well-ionization-chamber. Results: The position of the source and the spacing between different dwell-positions were reproducible within 1 mm accuracy by measuring the position of maximal dose using MapCheck2 in contrast to the film which showed a blurred image of the dwell positions due to limited film sensitivity to irradiation. The linearity of the dose with dwell times measured from MapCheck2 was superior to the linearity measured with ionization chamber due to higher signal-to-noise ratio of the diode readings. MapCheck2 provided more accurate measurement of the end effect with uncertainty < 1.5% in comparison with the ionization chamber uncertainty of 3%. Although MapCheck2 did not provide absolute calibration dosimeter for the activity of the source, it provided accurate tool for relative dose verification in HDR-brachytherapy. Conclusion: The 2D-array-diode-detector provides a practical, compact and accurate tool to perform quality assurance for HDR-brachytherapy with an Ir-192 source. The diodes in MapCheck2 have high radiation sensitivity and

  15. The Activity Check of Brachytherapy Isotope

    International Nuclear Information System (INIS)

    Kim, Gun Oh; Lee, Byung Koo; Kwon, Young Ho

    2004-01-01

    An isotope Ir-192, which is used in brachytherapy depends on import in whole quantities. There are a few ways for its activity. measurement using Welltype chamber or the way to rely on authentic decay table of manufacturer. In-air dosimetry using Farmer Chamber, etc. In this paper, let me introduce the way using Farmer chamber which is easier and simple. With the Farmer chamber and source calibration jig, take a measurement the activity of an isotope Ir-192 and compare the value with the value from decay table of manufacturer and check the activity of source. The result of measurement, compared the value from decay table, by ±2.1. (which belongs to recommendable value for AAPM ±5% as difference of error range). It is possible to use on clinical medicine. With the increase in use of brachytherapy, the increase of import is essential. And an accurate activity check of source is compulsory. For the activity check of source, it was possible to use Farmer chamber and source calibration jig without additional purchase of Well type chamber.

  16. A comparison of the relative biological effectiveness of low energy electronic brachytherapy sources in breast tissue: a Monte Carlo study.

    Science.gov (United States)

    White, Shane A; Reniers, Brigitte; de Jong, Evelyn E C; Rusch, Thomas; Verhaegen, Frank

    2016-01-07

    Electronic brachytherapy sources use low energy photons to treat the tumor bed during or after breast-conserving surgery. The relative biological effectiveness of two electronic brachytherapy sources was explored to determine if spectral differences due to source design influenced radiation quality and if radiation quality decreased with distance in the breast. The RBE was calculated through the number of DNA double strand breaks (RBEDSB) using the Monte Carlo damage simulator (MCDS) in combination with other Monte Carlo electron/photon spectrum calculations. 50kVp photons from the Intrabeam (Carl Zeiss Surgical) and Axxent (Xoft) through 40-mm spherical applicators were simulated to account for applicator and tissue attenuation in a variety of breast tissue compositions. 40kVp Axxent photons were also simulated. Secondary electrons (known to be responsible for most DNA damage) spectra at different distance were inputted into MCDS to calculate the RBEDSB. All RBEDSB used a cobalt-60 reference. RBEDSB data was combined with corresponding average photon spectrum energy for the Axxent and applied to model-based average photon energy distributions to produce an RBEDSB map of an accelerated partial breast irradiation (APBI) patient. Both Axxent and Intrabeam 50kVp spectra were shown to have a comparable RBEDSB of between 1.4 and 1.6 at all distances in spite of progressive beam hardening. The Axxent 40kVp also demonstrated a similar RBEDSB at distances. Most RBEDSB variability was dependent on the tissue type as was seen in rib (RBEDSB  ≈  1.4), gland (≈1.55), adipose (≈1.59), skin (≈1.52) and lung (≈1.50). RBEDSB variability between both sources was within 2%. A correlation was shown between RBEDSB and average photon energy and used to produce an RBEDSB map of a dose distribution in an APBI patient dataset. Radiation quality is very similar between electronic brachytherapy sources studied. No significant reductions in RBEDSB were observed with

  17. BRIT manual after loading brachytherapy kit for intracavitary: initial experience

    International Nuclear Information System (INIS)

    Aggarwal, Lalit M.; Mandal, Abhijit; Asthana, Anupam K.; Shahi, Uday P.; Pradhan, Satyajit

    2007-01-01

    Brachytherapy continues to serve as an important and rapidly evolving tool in the management of cancer. Technological developments in the last two decades have dramatic impact on the safe practice of brachytherapy. A wide range of brachytherapy sources and equipment are available for new therapeutic possibilities. However, decision making with regard to new brachytherapy facilities are need based and depend on the patient load, socioeconomic status of the patients, and funds available with the institution. Remote afterloading equipments are fast replacing the Manual After Loading (MAL) systems. However, keeping in view the large number of patients, who can not afford expensive treatment, the utility of manual after loading system which is inexpensive, cannot be ignored

  18. The establishment, nurturing, and fruition of a national transplutonium production program

    International Nuclear Information System (INIS)

    Bigelow, J.E.

    1992-01-01

    The first two slides describe the discovery of 252 Cf and the properties that make it useful as a neutron source. The next two describe the applications. The next two cover the history of the Market Development Program, which is pretty much phased out now, with most residual responsibilities transferred to Oak Ridge. The final slide illustrates the uses of 252 Cf that has been sold and commercially fabricated into neutron sources

  19. Evaluation of interpolation methods for TG-43 dosimetric parameters based on comparison with Monte Carlo data for high-energy brachytherapy sources.

    Science.gov (United States)

    Pujades-Claumarchirant, Ma Carmen; Granero, Domingo; Perez-Calatayud, Jose; Ballester, Facundo; Melhus, Christopher; Rivard, Mark

    2010-03-01

    The aim of this work was to determine dose distributions for high-energy brachytherapy sources at spatial locations not included in the radial dose function g L ( r ) and 2D anisotropy function F ( r , θ ) table entries for radial distance r and polar angle θ . The objectives of this study are as follows: 1) to evaluate interpolation methods in order to accurately derive g L ( r ) and F ( r , θ ) from the reported data; 2) to determine the minimum number of entries in g L ( r ) and F ( r , θ ) that allow reproduction of dose distributions with sufficient accuracy. Four high-energy photon-emitting brachytherapy sources were studied: 60 Co model Co0.A86, 137 Cs model CSM-3, 192 Ir model Ir2.A85-2, and 169 Yb hypothetical model. The mesh used for r was: 0.25, 0.5, 0.75, 1, 1.5, 2-8 (integer steps) and 10 cm. Four different angular steps were evaluated for F ( r , θ ): 1°, 2°, 5° and 10°. Linear-linear and logarithmic-linear interpolation was evaluated for g L ( r ). Linear-linear interpolation was used to obtain F ( r , θ ) with resolution of 0.05 cm and 1°. Results were compared with values obtained from the Monte Carlo (MC) calculations for the four sources with the same grid. Linear interpolation of g L ( r ) provided differences ≤ 0.5% compared to MC for all four sources. Bilinear interpolation of F ( r , θ ) using 1° and 2° angular steps resulted in agreement ≤ 0.5% with MC for 60 Co, 192 Ir, and 169 Yb, while 137 Cs agreement was ≤ 1.5% for θ energy brachytherapy sources, and was similar to commonly found examples in the published literature. For F ( r , θ ) close to the source longitudinal-axis, polar angle step sizes of 1°-2° were sufficient to provide 2% accuracy for all sources.

  20. A systematic evaluation of the dose-rate constant determined by photon spectrometry for 21 different models of low-energy photon-emitting brachytherapy sources.

    Science.gov (United States)

    Chen, Zhe Jay; Nath, Ravinder

    2010-10-21

    The aim of this study was to perform a systematic comparison of the dose-rate constant (Λ) determined by the photon spectrometry technique (PST) with the consensus value ((CON)Λ) recommended by the American Association of Physicists in Medicine (AAPM) for 21 low-energy photon-emitting interstitial brachytherapy sources. A total of 63 interstitial brachytherapy sources (21 different models with 3 sources per model) containing either (125)I (14 models), (103)Pd (6 models) or (131)Cs (1 model) were included in this study. A PST described by Chen and Nath (2007 Med. Phys. 34 1412-30) was used to determine the dose-rate constant ((PST)Λ) for each source model. Source-dependent variations in (PST)Λ were analyzed systematically against the spectral characteristics of the emitted photons and the consensus values recommended by the AAPM brachytherapy subcommittee. The values of (PST)Λ for the encapsulated sources of (103)Pd, (125)I and (131)Cs varied from 0.661 to 0.678 cGyh(-1) U(-1), 0.959 to 1.024 cGyh(-1)U(-1) and 1.066 to 1.073 cGyh(-1)U(-1), respectively. The relative variation in (PST)Λ among the six (103)Pd source models, caused by variations in photon attenuation and in spatial distributions of radioactivity among the source models, was less than 3%. Greater variations in (PST)Λ were observed among the 14 (125)I source models; the maximum relative difference was over 6%. These variations were caused primarily by the presence of silver in some (125)I source models and, to a lesser degree, by the variations in photon attenuation and in spatial distribution of radioactivity among the source models. The presence of silver generates additional fluorescent x-rays with lower photon energies which caused the (PST)Λ value to vary from 0.959 to 1.019 cGyh(-1)U(-1) depending on the amount of silver used by a given source model. For those (125)I sources that contain no silver, their (PST)Λ was less variable and had values within 1% of 1.024 cGyh(-1)U(-1). For the 16

  1. Audits in high dose rate brachytherapy in Brazil

    International Nuclear Information System (INIS)

    Marechal, M.H.; Rosa, L.A.; Velasco, A.; Paiva, E. de; Goncalves, M.; Castelo, L.C.

    2002-01-01

    The lack of well established dosimetry protocols for HDR sources is a point of great concern regarding the uniformity of procedures within a particular country. The main objective of this paper is to report the results of an implementation of the audit program in dosimetry of high dose rate brachytherapy sources used by the radiation therapy centers in Brazil. In Brazil, among 169 radiotherapy centers, 35 have HDR brachytherapy systems. This program started in August 2001 and until now eight radiotherapy services were audited. The audit program consists of the visit in loco to each center and the evaluation of the intensity of the source with a well type chamber specially design for HDR 192 Ir sources. The measurements was carried out with a HDR1000PLUS Brachytherapy Well Type Chamber and a MAX 4000 Electrometer, both manufactured by Standard Imaging Inc. The chamber was calibrated in air kerma strength by the Accredited Dosimetry Calibration Laboratory, Department of Medical Physics, University of Wisconsin in the USA. The same chamber was calibrated in Brazil using a 192 lr high dose rate source whose intensity was determined by 60 Co gamma rays and 250 kV x rays interpolation methodology. The Nk of 60 Co and 250 kV x rays were provided by the Brazilian National Standard Laboratory for Ionizing Radiation (LMNRI)

  2. MO-B-BRC-01: Introduction [Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Prisciandaro, J. [University of Michigan (United States)

    2016-06-15

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

  3. Neutron dosimetry at SLAC: Neutron sources and instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J.C.; Jenkins, T.M.; McCall, R.C.; Ipe, N.E.

    1991-10-01

    This report summarizes in detail the dosimetric characteristics of the five radioisotopic type neutron sources ({sup 238}PuBe, {sup 252}Cf, {sup 238}PuB, {sup 238}PuF{sub 4}, and {sup 238}PuLi) and the neutron instrumentation (moderated BF{sub 3} detector, Anderson-Braun (AB) detector, AB remmeter, Victoreen 488 Neutron Survey Meter, Beam Shut-Off Ionization Chamber, {sup 12}C plastic scintillator detector, moderated indium foil detector, and moderated and bare TLDs) that are commonly used for neutron dosimetry at the Stanford Linear Accelerator Center (SLAC). 36 refs,. 19 figs.

  4. Computed tomography in brachytherapy

    International Nuclear Information System (INIS)

    Mansfield, C.M.; Lee, K.R.; Dwyer, S.; Zellmer, D.; Cook, P.

    1983-01-01

    CT scanning adds to the ability to evaluate brachytherapy techniques. It provides an additional method in the assessment of patients who are candidates for or who are being treated by brachytherapy. The CT scan can give information regarding the position of the sources and their relation to the tumor and normal structures with greater ease than do orthogonal views. This makes it possible to accurately calculate areas of high or low dose. Potential areas of overdose can be recognized, thereby decreasing the chances of postbrachytherapy complications. CT scanning can be used at various levels of complexity in dosimetry evaluation. Adequate brachytherapy dosimetry information is obtainable from CT slices through one or more levels of the implanted volume. In some instances it is possible to obtain additional information by reconstructing the scans in other planes, e.g., coronal or sagittal. Three-dimensional viewing of the implant is desirable, but it should be pointed out that this approach is time-consuming and beyond the capabilities of most institutions at present. It will be necessary to continue work on three-dimensional treatment planning to make it readily available

  5. Monte Carlo dosimetry of a tandem positioned beta-emitting intravascular brachytherapy source train

    International Nuclear Information System (INIS)

    Wallace, Steven A.; Schumer, Wendy; Horrigan, Mark

    2002-01-01

    Prevention of restenosis following interventional coronary procedures with catheter based beta-emitting sources is currently under clinical trial investigations. Systems utilizing fixed length source trains limit the clinician's ability to increase the radiation source length as required. A technique known as 'pull back' is used when the segment of artery requiring radiation is longer than the available fixed length source train. In this instance, tandem positioning of the fixed length source is used to treat the longer length of artery. The aim of this study was to examine the dosimetry of the junction region associated with pull back treatments using a commercially available 90 Sr/Y catheter based intravascular brachytherapy source train. Dose profiles were calculated, using the Monte Carlo code MCNP4B, at radial distances of 1.5, 2.0, and 2.5 mm for pull back techniques using 2.5 mm overlapping, abutting, and 2.5 mm spaced source trains. Results at the protocol prescription radius of 2 mm showed a junction dose elevated 61% above prescription for 2.5 mm overlapping source trains. For 2.5 mm spaced trains, this figure falls to 64% below prescription dose. In contrast, abutted source trains exhibited only a 1% depression below prescription dose in the junction region. The reference point dose rate per unit activity of this source was found to be consistent with previous studies

  6. Intra coronary brachytherapy

    International Nuclear Information System (INIS)

    Ghofourian, H.; Ghahremani, A.; Oliaie, A.; Taghizadeh Asl, M.

    2002-01-01

    Despite the initial promise of vasculopathy intervention restenosis- a consequence of the (normal) would healing process-has emerged as a major problem. Angiographic restenosis has been reported in 40-60% of patients after successful P TCA. The basic mechanism of restenosis, (acute recoil, negative remodeling and neo intimal hyperplasia), are only partially counteracted by endovascular prosthetic devices (s tents). The rate of in-s tent restenosis, which is primarily caused by neo intimal hyperplasia due to the (micro) trauma of the arterial wall by the s tent struts, has been reduced to 18-32%. Ionizing (beta or gamma) radiations has been established as a potent treatment for malignant disorders. In recent years, there has also been increasing interest among clinicians in the management of benign lesions with radiation. Over the past several years, there has been a growing body of evidence that endovascular brachytherapy has a major impact on the biology of the restenosis. It must be underlined that understanding the biology and pathophysiology of restenosis and assessing various treatment options should preferably be a team effort, with the three g races b eing interventional cardiologist, nuclear oncologist, and industrial partners. The vast amount of data in over 20000 patients from a wide range of randomized controlled trials, has shown that brachytherapy is the only effective treatment for in-s tent restenosis. We are learning more and more about how to improve brachytherapy. While the new coated s tents that we heard about today is fascinating and extremely promising, brachytherapy still has a very important place in difficult patients, such as those with total occlusions, osti al lesions, left main lesions, multivessel disease and diabetes. Regarding to above mentioned tips, we (a research team work, in the Nuclear Research Center Of the Atomic Energy Organization Of Iran), focused on synthesis and preparation of radioactive materials for use in I c-B T. We

  7. Evaluation of neutron sources for ISAGE-in-situ-NAA for a future lunar mission.

    Science.gov (United States)

    Li, X; Breitkreutz, H; Burfeindt, J; Bernhardt, H-G; Trieloff, M; Hopp, J; Jessberger, E K; Schwarz, W H; Hofmann, P; Hiesinger, H

    2011-11-01

    For a future Moon landing, a concept for an in-situ NAA involving age determination using the (40)Ar-(39)Ar method is developed. A neutron source (252)Cf is chosen for sample irradiation on the Moon. A special sample-in-source irradiation geometry is designed to provide a homogeneous distribution of neutron flux at the irradiation position. Using reflector, the neutron flux is likely to increase by almost 200%. Sample age of 1Ga could be determined. Elemental analysis using INAA is discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. SU-E-T-284: Revisiting Reference Dosimetry for the Model S700 Axxent 50 KVp Electronic Brachytherapy Source

    International Nuclear Information System (INIS)

    Hiatt, JR; Rivard, MJ

    2014-01-01

    Purpose: The model S700 Axxent electronic brachytherapy source by Xoft was characterized in 2006 by Rivard et al. The source design was modified in 2006 to include a plastic centering insert at the source tip to more accurately position the anode. The objectives of the current study were to establish an accurate Monte Carlo source model for simulation purposes, to dosimetrically characterize the new source and obtain its TG-43 brachytherapy dosimetry parameters, and to determine dose differences between the source with and without the centering insert. Methods: Design information from dissected sources and vendor-supplied CAD drawings were used to devise the source model for radiation transport simulations of dose distributions in a water phantom. Collision kerma was estimated as a function of radial distance, r, and polar angle, θ, for determination of reference TG-43 dosimetry parameters. Simulations were run for 10 10 histories, resulting in statistical uncertainties on the transverse plane of 0.03% at r=1 cm and 0.08% at r=10 cm. Results: The dose rate distribution the transverse plane did not change beyond 2% between the 2006 model and the current study. While differences exceeding 15% were observed near the source distal tip, these diminished to within 2% for r>1.5 cm. Differences exceeding a factor of two were observed near θ=150° and in contact with the source, but diminished to within 20% at r=10 cm. Conclusions: Changes in source design influenced the overall dose rate and distribution by more than 2% over a third of the available solid angle external from the source. For clinical applications using balloons or applicators with tissue located within 5 cm from the source, dose differences exceeding 2% were observed only for θ>110°. This study carefully examined the current source geometry and presents a modern reference TG-43 dosimetry dataset for the model S700 source

  9. The need for international standardization in clinical beta dosimetry for brachytherapy

    International Nuclear Information System (INIS)

    Quast, U.; Boehm, J.; Kaulich, T.W.

    2002-01-01

    Beta radiation has found increasing interest in radiotherapy. Besides the curative treatment of small and medium-sized intraocular tumors by means of ophthalmic beta radiation plaques, intravascular brachytherapy has proven to successfully overcome the severe problem of restenosis after interventional treatment of arterial stenosis in coronaries and peripheral vessels in many clinical trials with a large number of patients. Prior to initiating procedures applying beta radiation in radiotherapy, however, there is a common need to specify methods for the determination and specification of the absorbed dose to water or tissue and their spatial distributions. The IAEA-TECDOC-1274 Calibration of photon and beta ray sources used in brachytherapy (2002) is a help for photon brachytherapy calibration. But, for beta seed and line sources, IAEA recommends well type ionization chambers as working standards which are far from measuring absorbed dose to water of the radiation clinically used. Although the application of such working standards seems to be more precise, large errors can occur when the medical physicist has to convert the calibration data to absorbed dose to water of the beta radiation emitted. The user must believe that the source is equally activated and that the manufacturer did not change the design and construction of the source encapsulation. With the DGMP Report 16 (2001) Guidelines for medical physical aspects of intravascular brachytherapy a very detailed code of practice is given, especially for the calibration and clinical dosimetry of intravascular beta radiation sources. As there is a global need for standardization in clinical dosimetry for intravascular brachytherapy utilizing beta radiation, the DIN-NAR, the German committee on standardization in radiology, task group dosimetry, has initiated an international adhoc working group for a new ISO work item proposal on the standardization of procedures in clinical dosimetry to guarantee reliable

  10. Dosimetric characterization of the GammaClip™{sup 169}Yb low dose rate permanent implant brachytherapy source for the treatment of nonsmall cell lung cancer postwedge resection

    Energy Technology Data Exchange (ETDEWEB)

    Currier, Blake [Medical Physics, University of Massachusetts Lowell, 1 University Avenue, Lowell, Massachusetts 01854 (United States); Munro, John J. III [Source Production and Equipment Co., Inc., 113 Teal Street, St. Rose, Louisiana 70087 (United States); Medich, David C. [Department of Physics, Worcester Polytechnic Institute, 100 Institute Road, Worcester, Massachusetts 01609 (United States)

    2013-08-15

    Purpose: A novel {sup 169}Yb low dose rate permanent implant brachytherapy source, the GammaClip™, was developed by Source Production and Equipment Co. (New Orleans, LA) which is designed similar to a surgical staple while delivering therapeutic radiation. In this report, the brachytherapy source was characterized in terms of “Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: Report of the AAPM and ESTRO” by Perez-Calatayud et al. [Med. Phys. 39, 2904–2929 (2012)] using the updated AAPM Task Group Report No. 43 formalism.Methods: Monte Carlo calculations were performed using Monte Carlo N-Particle 5, version 1.6 in water and air, the in-air photon spectrum filtered to remove photon energies below 10 keV in accordance with TG-43U1 recommendations and previously reviewed {sup 169}Yb energy cutoff levels [D. C. Medich, M. A. Tries, and J. M. Munro, “Monte Carlo characterization of an Ytterbium-169 high dose rate brachytherapy source with analysis of statistical uncertainty,” Med. Phys. 33, 163–172 (2006)]. TG-43U1 dosimetric data, including S{sub K}, D-dot (r,θ), Λ, g{sub L}(r), F(r, θ), φ{sub an}(r), and φ{sub an} were calculated along with their statistical uncertainties. Since the source is not axially symmetric, an additional set of calculations were performed to assess the resulting axial anisotropy.Results: The brachytherapy source's dose rate constant was calculated to be (1.22 ± 0.03) cGy h{sup −1} U{sup −1}. The uncertainty in the dose to water calculations, D-dot (r,θ), was determined to be 2.5%, dominated by the uncertainties in the cross sections. The anisotropy constant, φ{sub an}, was calculated to be 0.960 ± 0.011 and was obtained by integrating the anisotropy factor between 1 and 10 cm using a weighting factor proportional to r{sup −2}. The radial dose function was calculated at distances between 0.5 and 12 cm, with a maximum value of 1.20 at 5.15 ± 0.03 cm. Radial dose

  11. Comparison between methods for fixing radioactive iodine in silver substrate for manufacturing brachytherapy sources

    International Nuclear Information System (INIS)

    Souza, Carla Daruich

    2012-01-01

    Among the different ways to treat prostate cancer, brachytherapy with iodine- 125 seeds is an option that provides good results and fewer side effects. In the present study several deposition methods of radioactive iodine in a silver substrate were compared in order to choose the most suitable alternative for the routine production to be implemented at IPEN's laboratory. The methodology used was chosen based on the available infrastructure and experience of the researchers present. Therefore, the 131 I was used for testing (same chemical behavior as 131 I). Four methods were selected: Method 1 (test based on electrodeposition method developed by D.Kubiatowicz) presented 65.16% efficiency; Method 2 (chemical reaction based on the method developed by D. Kubiatowicz - HCl) with the result of 70.80% efficiency; method 3 (chemical reaction based on the method developed by Dr. Maria Elisa Rostelato) with 55.80% efficiency; Method 4 (IQ-IPEN) resulted in 99% efficiency. Since this method has more radioactive material fixation (which represents virtually the entire cost of the seed), the final price is the cheapest. This method is the suggested one to be implemented in the IPEN's laboratory for brachytherapy sources production. Besides, the method is the fasted one. (author)

  12. Design and dosimetric characteristics of a new endocavitary contact radiotherapy system using an electronic brachytherapy source

    International Nuclear Information System (INIS)

    Richardson, Susan; Garcia-Ramirez, Jose; Lu Wei; Myerson, Robert J.; Parikh, Parag

    2012-01-01

    Purpose: To present design aspects and acceptance tests performed for clinical implementation of electronic brachytherapy treatment of early stage rectal adenocarcinoma. A dosimetric comparison is made between the historically used Philips RT-50 unit and the newly developed Axxent ® Model S700 electronic brachytherapy source manufactured by Xoft (iCad, Inc.). Methods: Two proctoscope cones were manufactured by ElectroSurgical Instruments (ESI). Two custom surface applicators were manufactured by Xoft and were designed to fit and interlock with the proctoscope cones from ESI. Dose rates, half value layers (HVL), and percentage depth dose (PDD) measurements were made with the Xoft system and compared to historical RT-50 data. A description of the patient treatment approach and exposure rates during the procedure is also provided. Results: The electronic brachytherapy system has a lower surface dose rate than the RT-50. The dose rate to water on the surface from the Xoft system is approximately 2.1 Gy/min while the RT-50 is 10–12 Gy/min. However, treatment times with Xoft are still reasonable. The HVLs and PDDs between the two systems were comparable resulting in similar doses to the target and to regions beyond the target. The exposure rate levels around a patient treatment were acceptable. The standard uncertainty in the dose rate to water on the surface is approximately ±5.2%. Conclusions: The Philips RT-50 unit is an out-of-date radiotherapy machine that is no longer manufactured with limited replacement parts. The use of a custom-designed proctoscope and Xoft surface applicators allows delivery of a well-established treatment with the ease of a modern radiotherapy device. While the dose rate is lower with the use of Xoft, the treatment times are still reasonable. Additionally, personnel may stand farther away from the Xoft radiation source, thus potentially reducing radiation exposure to the operator and other personnel.

  13. Design and dosimetric characteristics of a new endocavitary contact radiotherapy system using an electronic brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, Susan; Garcia-Ramirez, Jose; Lu Wei; Myerson, Robert J.; Parikh, Parag [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States); Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201 (United States); Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States)

    2012-11-15

    Purpose: To present design aspects and acceptance tests performed for clinical implementation of electronic brachytherapy treatment of early stage rectal adenocarcinoma. A dosimetric comparison is made between the historically used Philips RT-50 unit and the newly developed Axxent{sup Registered-Sign} Model S700 electronic brachytherapy source manufactured by Xoft (iCad, Inc.). Methods: Two proctoscope cones were manufactured by ElectroSurgical Instruments (ESI). Two custom surface applicators were manufactured by Xoft and were designed to fit and interlock with the proctoscope cones from ESI. Dose rates, half value layers (HVL), and percentage depth dose (PDD) measurements were made with the Xoft system and compared to historical RT-50 data. A description of the patient treatment approach and exposure rates during the procedure is also provided. Results: The electronic brachytherapy system has a lower surface dose rate than the RT-50. The dose rate to water on the surface from the Xoft system is approximately 2.1 Gy/min while the RT-50 is 10-12 Gy/min. However, treatment times with Xoft are still reasonable. The HVLs and PDDs between the two systems were comparable resulting in similar doses to the target and to regions beyond the target. The exposure rate levels around a patient treatment were acceptable. The standard uncertainty in the dose rate to water on the surface is approximately {+-}5.2%. Conclusions: The Philips RT-50 unit is an out-of-date radiotherapy machine that is no longer manufactured with limited replacement parts. The use of a custom-designed proctoscope and Xoft surface applicators allows delivery of a well-established treatment with the ease of a modern radiotherapy device. While the dose rate is lower with the use of Xoft, the treatment times are still reasonable. Additionally, personnel may stand farther away from the Xoft radiation source, thus potentially reducing radiation exposure to the operator and other personnel.

  14. Atmospheric observations for quantifying emissions of point-source synthetic greenhouse gases (CF4, NF3 and HFC-23)

    Science.gov (United States)

    Arnold, Tim; Manning, Alistair J.; Li, Shanlan; Kim, Jooil; Park, Sunyoung; Fraser, Paul J.; Mitrevski, Blagoj; Steele, L. Paul; Krummel, Paul B.; Mühle, Jens; Weiss, Ray F.

    2016-04-01

    The fluorinated species carbon tetrafluoride (CF4; PFC-14), nitrogen trifluoride (NF3) and trifluoromethane (CHF3; HFC-23) are potent greenhouse gases with 100-year global warming potentials of 6,630, 16,100 and 12,400, respectively. Unlike the majority of CFC-replacement compounds that are emitted from fugitive and mobile emission sources, these gases are largely emitted from large single point sources - semiconductor manufacturing facilities (all three), aluminium smelting plants (CF4) and chlorodifluoromethane factories (HFC-23). In this work we show the potential for atmospheric measurements to understand regional sources of these gases and to highlight emission 'hotspots'. We target our analysis on measurements from two Advanced Global Atmospheric Gases Experiment (AGAGE) long term monitoring sites that are particularly sensitive to regional emissions of these gases: Gosan on Jeju Island in the Republic of Korea and Cape Grim on Tasmania in Australia. These sites measure CF4, NF3 and HFC-23 alongside a suite of greenhouse and stratospheric ozone depleting gases every two hours using automated in situ gas-chromatography mass-spectrometry instrumentation. We couple each measurement to an analysis of air history using the regional atmospheric transport model NAME (Numerical Atmospheric dispersion Modelling Environment) driven by 3D meteorology from the Met Office's Unified Model, and use a Bayesian inverse method (InTEM - Inversion Technique for Emission Modelling) to calculate yearly emission changes over a decade (2005-2015) at high spatial resolution. At present these gases make a small contribution to global radiative forcing, however, given that their impact could rise significantly and that point sources of such gases can be mitigated, atmospheric monitoring could be an important tool for aiding emissions reduction policy.

  15. The IPEM code of practice for determination of the reference air kerma rate for HDR 192Ir brachytherapy sources based on the NPL air kerma standard

    International Nuclear Information System (INIS)

    Bidmead, A M; Sander, T; Nutbrown, R F; Locks, S M; Lee, C D; Aird, E G A; Flynn, A

    2010-01-01

    This paper contains the recommendations of the high dose rate (HDR) brachytherapy working party of the UK Institute of Physics and Engineering in Medicine (IPEM). The recommendations consist of a Code of Practice (COP) for the UK for measuring the reference air kerma rate (RAKR) of HDR 192 Ir brachytherapy sources. In 2004, the National Physical Laboratory (NPL) commissioned a primary standard for the realization of RAKR of HDR 192 Ir brachytherapy sources. This has meant that it is now possible to calibrate ionization chambers directly traceable to an air kerma standard using an 192 Ir source (Sander and Nutbrown 2006 NPL Report DQL-RD 004 (Teddington: NPL) http://publications.npl.co.uk). In order to use the source specification in terms of either RAKR, .K R (ICRU 1985 ICRU Report No 38 (Washington, DC: ICRU); ICRU 1997 ICRU Report No 58 (Bethesda, MD: ICRU)), or air kerma strength, S K (Nath et al 1995 Med. Phys. 22 209-34), it has been necessary to develop algorithms that can calculate the dose at any point around brachytherapy sources within the patient tissues. The AAPM TG-43 protocol (Nath et al 1995 Med. Phys. 22 209-34) and the 2004 update TG-43U1 (Rivard et al 2004 Med. Phys. 31 633-74) have been developed more fully than any other protocol and are widely used in commercial treatment planning systems. Since the TG-43 formalism uses the quantity air kerma strength, whereas this COP uses RAKR, a unit conversion from RAKR to air kerma strength was included in the appendix to this COP. It is recommended that the measured RAKR determined with a calibrated well chamber traceable to the NPL 192 Ir primary standard is used in the treatment planning system. The measurement uncertainty in the source calibration based on the system described in this COP has been reduced considerably compared to other methods based on interpolation techniques.

  16. Inverse planning in brachytherapy from radium to high rate 192 iridium afterloading

    International Nuclear Information System (INIS)

    Lahanas, M.; Mould, R.F.; Baltas, D.; Karauzakis, K.; Giannouli, S.; Baltas, D.

    2004-01-01

    We consider the inverse planning problem in brachytherapy, i.e. the problem to determine an optimal number of catheters, number of sources for low-dose rate brachytherapy (LDR) and the optimal dwell times for high-dose rate brachytherapy (HDR) necessary to obtain an optimal as possible dose distribution. Starting from the 1930s, inverse planning for LDR brachytherapy used geometrically derived rules to determine the optimal placement of sources in order to achieve a uniform dose distribution of a specific level in planes, spheres and cylinders. Rules and nomograms were derived which still are widely used. With the rapid development of 3D imaging technologies and the rapidly increasing computer power we have now entered the new era of computer-based inverse planning in brachytherapy. The inverse planning is now an optimisation process adapted to the individual geometry of the patient. New inverse planning optimisation algorithms are anatomy-based that consider the real anatomy of the tumour and the organs at risk (OAR). Computer-based inverse planning considers various effects such as stability of solutions for seed misplacements which cannot ever be solved analytically without gross simplifications. In the last few years multiobjective (MO) inverse planning algorithms have been developed which recognise the MO optimisation problem which is inherent in inverse planning in brachytherapy. Previous methods used a trial and error method to obtain a satisfactory solution. MO optimisation replaces this trial and error process by presenting a representative set of dose distributions that can be obtained. With MO optimisation it is possible to obtain information that can be used to obtain the optimum number of catheters, their position and the optimum distribution of dwell times for HDR brachytherapy. For LDR brachytherapy also the stability of solutions due to seed migration can also be improved. A spectrum of alternative solutions is available and the treatment planner

  17. Determination of factors through Monte Carlo method for Fricke dosimetry from 192Ir sources for brachytherapy

    International Nuclear Information System (INIS)

    David, Mariano Gazineu; Salata, Camila; Almeida, Carlos Eduardo

    2014-01-01

    The Laboratorio de Ciencias Radiologicas develops a methodology for the determination of the absorbed dose to water by Fricke chemical dosimetry method for brachytherapy sources of 192 Ir high dose rate and have compared their results with the laboratory of the National Research Council Canada. This paper describes the determination of the correction factors by Monte Carlo method, with the Penelope code. Values for all factors are presented, with a maximum difference of 0.22% for their determination by an alternative way. (author)

  18. Design of a portable directional neutron source finder

    International Nuclear Information System (INIS)

    Yamanishi, Hirokuni

    2005-01-01

    An instrument that determines the direction of a remote existing neutron source has been designed. This instrument combines a polyethylene block and four 3 He counter tubes. The advantages of the instrument are portability and good angular resolution. The count from the detector was varied with the neutron incident angle due to the moderator. Using this characteristic, the direction of the neutron source can be measured precisely by revising the axis of the instrument so that the difference between the four detectors measurements is minimized. Consequently, the direction of the central axis of the instrument in which the response difference of the four detectors reaches a minimum indicates the direction of the neutron source. The practical use of the instrument was demonstrated by 252 Cf source irradiation experiment and MCNP simulation

  19. American brachytherapy society (ABS) consensus guidelines for brachytherapy of esophageal cancer

    International Nuclear Information System (INIS)

    Gaspar, Laurie E.; Nag, Subir; Herskovic, Arnold; Mantravadi, Rao; Speiser, Burton

    1997-01-01

    Introduction: There is wide variation in the indications, treatment regimens, and dosimetry for brachytherapy in the treatment of cancer of the esophagus. No guidelines for optimal therapy currently exist. Methods and Materials: Utilizing published reports and clinical experience, representatives of the Clinical Research Committee of the American Brachytherapy Society (ABS) formulated guidelines for brachytherapy in esophageal cancer. Results: Recommendations were made for brachytherapy in the definitive and palliative treatment of esophageal cancer. (A) Definitive treatment: Good candidates for brachytherapy include patients with unifocal thoracic adeno- or squamous cancers ≤ 10 cm in length, with no evidence of intra-abdominal or metastatic disease. Contraindications include tracheal or bronchial involvement, cervical esophagus location, or stenosis that cannot be bypassed. The esophageal brachytherapy applicator should have an external diameter of 6-10 mm. If 5FU-based chemotherapy and 45-50-Gy external beam are used, recommended brachytherapy is either: (i) HDR 10 Gy in two weekly fractions of 5 Gy each; or (ii) LDR 20 Gy in a single course at 0.4-1 Gy/hr. All doses are specified 1 cm from the midsource or middwell position. Brachytherapy should follow external beam radiation therapy and should not be given concurrently with chemotherapy. (B) Palliative treatment: Patients with adeno- or squamous cancers of the thoracic esophagus with distant metastases or unresectable local disease progression/recurrence after definitive radiation treatment should be considered for brachytherapy with palliative intent. After limited dose (30 Gy) EBRT, the recommended brachytherapy is either: (i) HDR 10-14 Gy in one or two fractions; or (ii) LDR 20-25 Gy in a single course at 0.4-1 Gy/hr. The need for external beam radiation in newly diagnosed patients with a life expectancy of less than 3 months is controversial. In these cases, HDR of 15-20 Gy in two to four fractions or

  20. MO-D-BRD-01: Clinical Implementation of An Electronic Brachytherapy Program for the Skin

    International Nuclear Information System (INIS)

    Ouhib, Z.

    2015-01-01

    Electronic brachytherapy (eBT) has seen an insurgence of manufacturers entering the US market for use in radiation therapy. In addition to the established interstitial, intraluminary, and intracavitary applications of eBT, many centers are now using eBT to treat skin lesions. It is important for medical physicists working with electronic brachytherapy sources to understand the basic physics principles of the sources themselves as well as the variety of applications for which they are being used. The calibration of the sources is different from vendor to vendor and the traceability of calibrations has evolved as new sources came to market. In 2014, a new air-kerma based standard was introduced by the National Institute of Standards and Technology (NIST) to measure the output of an eBT source. Eventually commercial treatment planning systems should accommodate this new standard and provide NIST traceability to the end user. The calibration and commissioning of an eBT system is unique to its application and typically entails a list of procedural recommendations by the manufacturer. Commissioning measurements are performed using a variety of methods, some of which are modifications of existing AAPM Task Group protocols. A medical physicist should be familiar with the different AAPM Task Group recommendations for applicability to eBT and how to properly adapt them to their needs. In addition to the physical characteristics of an eBT source, the photon energy is substantially lower than from HDR Ir-192 sources. Consequently, tissue-specific dosimetry and radiobiological considerations are necessary when comparing these brachytherapy modalities and when making clinical decisions as a radiation therapy team. In this session, the physical characteristics and calibration methodologies of eBt sources will be presented as well as radiobiology considerations and other important clinical considerations. Learning Objectives: To understand the basic principles of electronic

  1. Monte Carlo characterization of the Gamma-Med Hdr plus Ir-192 brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, E.; Sosa, M. A.; Gil V, A. [Universidad de Guanajuato, Division de Ciencias e Ingenierias, Av. Insurgentes 2354, 37150 Leon, Guanajuato (Mexico); Monzon, E., E-mail: eric_1985@fisica.ugto.mx [IMSS, Unidad Medica de Alta Especialidad No. 1, Av. Adolfo Lopez Mateos 1813, 37340 Leon, Guanajuato (Mexico)

    2015-10-15

    Full text: The MCNP4C Monte Carlo code was used to simulate the dosimetry around the Gamma-Med Hdr Plus iridium-192 brachytherapy source in both air/vacuum and water environments. Dosimetry data in water was calculated and are presented into an away-along table. All dosimetric quantities recommended by the AAPM Task Group 43 report have been also calculated. These quantities are air kerma strength, dose rate constant, radial dose function and anisotropy function. The obtained data are compared to this source reference data, finding results in good agreement with them. In this study, recommendations of the AAPM TG-43U1 report have been followed and comply with the most recent AAPM and ESTRO physics committee recommendations about Monte Carlo techniques. The data in the present study complement published data and can be used as input in the Tps or as benchmark data to verify the results of the treatment planning systems as well as a means of comparison with other datasets from this source. (Author)

  2. Monte Carlo characterization of the Gamma-Med Hdr plus Ir-192 brachytherapy source

    International Nuclear Information System (INIS)

    Reyes, E.; Sosa, M. A.; Gil V, A.; Monzon, E.

    2015-10-01

    Full text: The MCNP4C Monte Carlo code was used to simulate the dosimetry around the Gamma-Med Hdr Plus iridium-192 brachytherapy source in both air/vacuum and water environments. Dosimetry data in water was calculated and are presented into an away-along table. All dosimetric quantities recommended by the AAPM Task Group 43 report have been also calculated. These quantities are air kerma strength, dose rate constant, radial dose function and anisotropy function. The obtained data are compared to this source reference data, finding results in good agreement with them. In this study, recommendations of the AAPM TG-43U1 report have been followed and comply with the most recent AAPM and ESTRO physics committee recommendations about Monte Carlo techniques. The data in the present study complement published data and can be used as input in the Tps or as benchmark data to verify the results of the treatment planning systems as well as a means of comparison with other datasets from this source. (Author)

  3. SU-F-T-05: Dosimetric Evaluation and Validation of Newlydeveloped Well Chamber for Use in the Calibration of Brachytherapy Sources

    Energy Technology Data Exchange (ETDEWEB)

    Saminathan, S; Godson, H; Ponmalar, R; Manickam, R [Kidwai Memorial Institute of Oncology, Bangalore, Karnataka (India); Mazarello, J [Rosalina India private limited, Mumbai, Maharastra (India)

    2016-06-15

    Purpose: To evaluate the dosimetric characteristics of newly developed well type ionization chamber and to validate the results with the commercially available calibrated well chambers that are being used for the calibration of brachytherapy sources. Methods: The newly developed well type ionization chamber (BDS 1000) has been designed for the convenient use in brachytherapy which is open to atmospheric condition. The chamber has a volume of 240 cm3 and weight of 2.5 Kg. The calibration of the radioactive source with activities from 0.01 mCi to 20 Ci can be carried out using this chamber. The dosimetric parameters such as leakage current, stability, scattering effect, ion collection efficiency, reference air kerma rate and nominal response with energy were carried out with the BDS 1000 well type ion chamber. The evaluated dosimetric characteristics of BDS1000 well chamber were validated with two other commercially available well chambers (HDR 1000 plus and BTC/3007). Results: The measured leakage current observed was negligible for the newly developed BDS 1000 well type ion chamber. The ion collection efficiency was close to 1 and the response of the chamber was found to be very stable. The determined sweet spot was at 42 mm from bottom of the chamber insert. The reference air kerma rate was found to be 4.634 × 105 Gym2hr-1A-1 for the BDS 1000 well chamber. The overall dosimetric characteristics of BDS 1000 well chamber was in good agreement with the dosimetric properties of other two well chambers. Conclusion: The dosimetric study shows that the newly developed BDS 1000 well type ionization chamber is high sensitive and reliable chamber for reference air kerma strength calibration. The results obtained confirm that this chamber can be used for the calibration of HDR and LDR brachytherapy sources.

  4. Radiobiological considerations in gynaecological HDR and LDR brachytherapy

    International Nuclear Information System (INIS)

    Bauer, M.; Schulz-Wendtland, R.

    1989-01-01

    In brachytherapy the advantages of high dose rate over low dose rate afterloading therapy were obvious. Out-patient treatment becomes possible, the position of the sources is reproducible and can be observed during the treatment and the patients have to be immobilised for only a short time, giving less psychological stress and a decreased risk of thrombosis and embolism. When changing from LDR to HDR afterloading therapy we are not yet able to evaluate its biological impact. Radiobiological considerations and our experimental data, however, give us the following clinical consequences by using HDR brachytherapy: There is a need for about 15 fractions or more and each increase in dose rate requires higher fractioning. Due to the steep dose rate decline and the inhomogeneous dose distribution, multiple equivalence factors are necessary when fractioning is not sufficiently high. Correction factors to reduce the dose close to the source are low, with increasing distance from the source they increase. If HDR radiation therapy is used, the percutaneous dose in the pelvic wall region should be reduced. The reduction of the dose in HDR brachytherapy is a compromise to limit the side effects caused by the radiation. The drawback is a small therapeutic range and reduced therapeutic effectivity at the tumour. (orig.) [de

  5. Multihelix rotating shield brachytherapy for cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dadkhah, Hossein [Department of Biomedical Engineering, University of Iowa, 1402 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242 (United States); Kim, Yusung; Flynn, Ryan T., E-mail: ryan-flynn@uiowa.edu [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Wu, Xiaodong [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 and Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242 (United States)

    2015-11-15

    Purpose: To present a novel brachytherapy technique, called multihelix rotating shield brachytherapy (H-RSBT), for the precise angular and linear positioning of a partial shield in a curved applicator. H-RSBT mechanically enables the dose delivery using only linear translational motion of the radiation source/shield combination. The previously proposed approach of serial rotating shield brachytherapy (S-RSBT), in which the partial shield is rotated to several angular positions at each source dwell position [W. Yang et al., “Rotating-shield brachytherapy for cervical cancer,” Phys. Med. Biol. 58, 3931–3941 (2013)], is mechanically challenging to implement in a curved applicator, and H-RSBT is proposed as a feasible solution. Methods: A Henschke-type applicator, designed for an electronic brachytherapy source (Xoft Axxent™) and a 0.5 mm thick tungsten partial shield with 180° or 45° azimuthal emission angles and 116° asymmetric zenith angle, is proposed. The interior wall of the applicator contains six evenly spaced helical keyways that rigidly define the emission direction of the partial radiation shield as a function of depth in the applicator. The shield contains three uniformly distributed protruding keys on its exterior wall and is attached to the source such that it rotates freely, thus longitudinal translational motion of the source is transferred to rotational motion of the shield. S-RSBT and H-RSBT treatment plans with 180° and 45° azimuthal emission angles were generated for five cervical cancer patients with a diverse range of high-risk target volume (HR-CTV) shapes and applicator positions. For each patient, the total number of emission angles was held nearly constant for S-RSBT and H-RSBT by using dwell positions separated by 5 and 1.7 mm, respectively, and emission directions separated by 22.5° and 60°, respectively. Treatment delivery time and tumor coverage (D{sub 90} of HR-CTV) were the two metrics used as the basis for evaluation and

  6. Comparison of TG-43 and TG-186 in breast irradiation using a low energy electronic brachytherapy source.

    Science.gov (United States)

    White, Shane A; Landry, Guillaume; Fonseca, Gabriel Paiva; Holt, Randy; Rusch, Thomas; Beaulieu, Luc; Verhaegen, Frank; Reniers, Brigitte

    2014-06-01

    The recently updated guidelines for dosimetry in brachytherapy in TG-186 have recommended the use of model-based dosimetry calculations as a replacement for TG-43. TG-186 highlights shortcomings in the water-based approach in TG-43, particularly for low energy brachytherapy sources. The Xoft Axxent is a low energy (S700, was created and validated against experimental data. CT scans of the patients were used to create realistic multi-tissue/heterogeneous models with breast tissue segmented using a published technique. Alternative water models were used to isolate the influence of tissue heterogeneity and backscatter on the dose distribution. Dose calculations were performed using Geant4 according to the original treatment parameters. The effect of the Axxent balloon applicator used in APBI which could not be modeled in the CT-based model, was modeled using a novel technique that utilizes CAD-based geometries. These techniques were validated experimentally. Results were calculated using two dose reporting methods, dose to water (Dw,m) and dose to medium (Dm,m), for the heterogeneous simulations. All results were compared against TG-43-based dose distributions and evaluated using dose ratio maps and DVH metrics. Changes in skin and PTV dose were highlighted. All simulated heterogeneous models showed a reduced dose to the DVH metrics that is dependent on the method of dose reporting and patient geometry. Based on a prescription dose of 34 Gy, the average D90 to PTV was reduced by between ~4% and ~40%, depending on the scoring method, compared to the TG-43 result. Peak skin dose is also reduced by 10%-15% due to the absence of backscatter not accounted for in TG-43. The balloon applicator also contributed to the reduced dose. Other ROIs showed a difference depending on the method of dose reporting. TG-186-based calculations produce results that are different from TG-43 for the Axxent source. The differences depend strongly on the method of dose reporting. This study

  7. Photon spectrometry for the determination of the dose-rate constant of low-energy photon-emitting brachytherapy sources

    International Nuclear Information System (INIS)

    Chen, Zhe Jay; Nath, Ravinder

    2007-01-01

    Accurate determination of dose-rate constant (Λ) for interstitial brachytherapy sources emitting low-energy photons (<50 keV) has remained a challenge in radiation dosimetry because of the lack of a suitable absolute dosimeter for accurate measurement of the dose rates near these sources. Indeed, a consensus value of Λ taken as the arithmetic mean of the dose-rate constants determined by different research groups and dosimetry techniques has to be used at present for each source model in order to minimize the uncertainties associated with individual determinations of Λ. Because the dosimetric properties of a source are fundamentally determined by the characteristics of the photons emitted by the source, a new technique based on photon spectrometry was developed in this work for the determination of dose-rate constant. The photon spectrometry technique utilized a high-resolution gamma-ray spectrometer to measure source-specific photon characteristics emitted by the low-energy sources and determine their dose-rate constants based on the measured photon-energy spectra and known dose-deposition properties of mono-energetic photons in water. This technique eliminates many of the difficulties arising from detector size, the energy dependence of detector sensitivity, and the use of non-water-equivalent solid phantoms in absolute dose rate measurements. It also circumvents the uncertainties that might be associated with the source modeling in Monte Carlo simulation techniques. It was shown that the estimated overall uncertainty of the photon spectrometry technique was less than 4%, which is significantly smaller than the reported 8-10% uncertainty associated with the current thermo-luminescent dosimetry technique. In addition, the photon spectrometry technique was found to be stable and quick in Λ determination after initial setup and calibration. A dose-rate constant can be determined in less than two hours for each source. These features make it ideal to determine

  8. Afterloading techniques in brachytherapy

    International Nuclear Information System (INIS)

    Kirsch, M.; Orban, R.; Lorenz, B.

    1981-01-01

    The advantages of applying modern afterloading methods in brachytherapie of malignant diseases are outlined. They include, among other things, a considerable reduction in radiation exposure to staff involved. Furthermore, the radiation protection requirements imposed by the licensing authority on the construction, equipment and operation of remote controlled afterloading installations with gamma sources of up to 4 TBq (108 Ci) have been compiled. (author)

  9. Preparations for the start-up of a research program in nuclear safeguards at Chalmers

    International Nuclear Information System (INIS)

    Avdic, Senada; Pazsit, Imre

    2004-03-01

    The Department of Reactor Physics at Chalmers University of Technology plans to start-up a research program in nuclear safeguards and nuclear material management. The program is aimed at utilizing the experimental facilities as well as the experience in reactor physics, criticality safety, signal processing and unfolding, and experimental nuclear techniques, in tackling problems in non-destructive assay (NDA) of nuclear materials. For the introductory part of this program, support has been received from the Swedish Nuclear Power Inspectorate to host Dr. Senada Avdic, University of Tuzla, Bosnia, as a post-doc for three months to participate in the preparatory program. The preparations were focussed on a survey of existing active non-destructive assay methods and preparations of their application in the experimental and theoretical/calculational research of our Department. The methods surveyed comprise - the use of a 252 Cf source in active NDA measurements; - planning of an experiment with the existing equipments of the Department; - time correlation measurements with a 252 Cf source and/or a 252 Cf detector; - Monte Carlo simulations of the time correlations between gammas and neutrons from a measurement with a 252 Cf detector: the MCNP-PoliMi code; - Identification of fissile material (enrichment/mass) with 252 Cf measurements; the use of various unfolding techniques (artificial neural networks) for identifying nuclear parameters; use of neutron activation analysis with a neutron generator for determination of distribution of material in an unknown sample; - determination of fissile material content by measurements of delayed neutrons

  10. Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: report of the AAPM and ESTRO.

    Science.gov (United States)

    Perez-Calatayud, Jose; Ballester, Facundo; Das, Rupak K; Dewerd, Larry A; Ibbott, Geoffrey S; Meigooni, Ali S; Ouhib, Zoubir; Rivard, Mark J; Sloboda, Ron S; Williamson, Jeffrey F

    2012-05-01

    Recommendations of the American Association of Physicists in Medicine (AAPM) and the European Society for Radiotherapy and Oncology (ESTRO) on dose calculations for high-energy (average energy higher than 50 keV) photon-emitting brachytherapy sources are presented, including the physical characteristics of specific (192)Ir, (137)Cs, and (60)Co source models. This report has been prepared by the High Energy Brachytherapy Source Dosimetry (HEBD) Working Group. This report includes considerations in the application of the TG-43U1 formalism to high-energy photon-emitting sources with particular attention to phantom size effects, interpolation accuracy dependence on dose calculation grid size, and dosimetry parameter dependence on source active length. Consensus datasets for commercially available high-energy photon sources are provided, along with recommended methods for evaluating these datasets. Recommendations on dosimetry characterization methods, mainly using experimental procedures and Monte Carlo, are established and discussed. Also included are methodological recommendations on detector choice, detector energy response characterization and phantom materials, and measurement specification methodology. Uncertainty analyses are discussed and recommendations for high-energy sources without consensus datasets are given. Recommended consensus datasets for high-energy sources have been derived for sources that were commercially available as of January 2010. Data are presented according to the AAPM TG-43U1 formalism, with modified interpolation and extrapolation techniques of the AAPM TG-43U1S1 report for the 2D anisotropy function and radial dose function.

  11. Ultrasonography-guided cobalt-60 brachytherapy for malignant glioma

    International Nuclear Information System (INIS)

    Sakai, Noboru; Takenaka, Katsunobu; Ueda, Tatsuya

    1989-01-01

    Brachytherapy with cobalt-60 source is reported. In this method it is characterized that the source is inserted interstitially with remote control system by after-loading method via outer catheter (using tandem tube), which was established in the center of residual tumor, using ultrasonography guide with trepanation, or intraoperatively put within the dead space after tumor resection. Six cases of deep-seated and recurrent malignant glioma, were treated with this method. A total dose of 20 to 45 Gy (10 to 15 Gy/day for 2 to 3 days) was delivered to the target. Additionally conventional external irradiation was followed. The effect of cobalt-60 brachytherapy on such tumors were favorable especially for well-circumscribed glioma less than 3 cm on CT scan. (author)

  12. System optimization for continuous on-stream elemental analysis using low-output isotopic neutron sources

    International Nuclear Information System (INIS)

    Rizk, R.A.M.

    1989-01-01

    In continuous on-stream neutron activation analysis, the material to be analyzed may be continuously recirculated in a closed loop system between an activation source and a shielded detector. In this paper an analytical formulation of the detector response for such a system is presented. This formulation should be useful in optimizing the system design parameters for specific applications. A study has been made of all parameters that influence the detector response during on-stream analysis. Feasibility applications of the method to solutions of manganese and vanadium using a 5 μg 252 Cf neutron source are demonstrated. (author)

  13. Verification and analysis of the positioning of a source of brachytherapy high dose within an applicator gynecological interstitial fletcher Utrecht TC/RM

    International Nuclear Information System (INIS)

    Panedo Cobos, J. M.; Garcia castejon, M. A.; Huertas Martinez, C.; Gomez-Tejedor Alonso, S.; Rincon Perez, M.; Luna Tirado, J.; Perez Casas, A. M.

    2013-01-01

    Applicators are guides that circulate and are located within the patient brachytherapy sources. Applicators can suffer mechanical deformations due to processes of sterilization or shock, which may result in that the source do not place within these very precise and coincides with the planned. In these cases the planned treatment deviate actually managed. The object of this study is to verify that the position of the source into the dispenser coincides with the planned position, with a procedure that is described. (Author)

  14. Radiation safety and gynaecological brachytherapy

    International Nuclear Information System (INIS)

    Crawford, L.

    1985-01-01

    In 1983, the Radiation Control Section of the South Australian Health Commission conducted an investigation into radiation safety practices in gynaecological brachytherapy. Part of the investigation included a study of the transportation of radioactive sources between hospitals. Several deficiences in radiation safety were found in the way these sources were being transported. New transport regulations came into force in South Australia in July 1984 and since then there have been many changes in the transportation procedure

  15. Radiation protection procedures and dose to the staff in brachytherapy with permanent implant of the sources

    International Nuclear Information System (INIS)

    Tosi, G.; Cattani, F.

    2002-01-01

    The treatment of intra capsular prostate cancers with the permanent implantation of low energy sealed radioactive sources (''103 Pd-''125I) offers the same probability of curing the tumours as surgery and external-beam radiotherapy with a minimum incidence of unwanted side-effects. The first attempts of using sealed sources for treating prostate cancers go back to 1917, when Barringer reported the results obtained with the implant of ''236Ra needles. Beginning from that period the interest for prostate brachytherapy has shown a fluctuating trend, due especially to the technological possibilities and to the status of the alternative treatment modalities (surgery, external radiotherapy). The main reason of the substantial failure of brachytherapy as compared to the two other treatment modalities had two main causes: the energy, too high ( E≅ 840 keV), of γ-radiation emitted by ''226 Ra in equilibrium with its decay products and the lack of imaging techniques able to visualize with sufficient accuracy both the prostate and the arrangement, inside it, of the radioactive sources. The employ of low energy γ-emitting radionuclides began in 1974, when Whitmore et al. working at the Sloan Kettering Memorial Cancer Hospital of New York suggested the use of ''125 I sealed sources for the realisation of interstitial permanent implants. Also this attempt, though reducing the side effects typical of the surgical intervention (incontinence, impotence), did non give the expected results in terms of local control of the disease and, as a consequence, of the survival's length. This partial failure was attributed to the fact that, in most cases the dose distribution inside the target volume was not homogeneous, due to the inadequacy of the available imaging techniques used for checking the real position of the sources, during their manual insertion in the tissues. In the last ten years,however, great progresses have been made in the US i maging techniques, in the manufacture of

  16. New fit of thermal neutron constants (TNC for 233,235U, 239,241Pu and 252Cf(sf: Microscopic vs. maxwellian data

    Directory of Open Access Journals (Sweden)

    Pronyaev Vladimir G.

    2017-01-01

    Full Text Available An IAEA project to update the Neutron Standards is near completion. Traditionally, the Thermal Neutron Constants (TNC evaluated data by Axton for thermal-neutron scattering, capture and fission on four fissile nuclei and the total nu-bar of 252Cf(sf are used as input in the combined least-square fit with neutron cross section standards. The evaluation by Axton (1986 was based on a least-square fit of both thermal-spectrum averaged cross sections (Maxwellian data and microscopic cross sections at 2200 m/s. There is a second Axton evaluation based exclusively on measured microscopic cross sections at 2200 m/s (excluding Maxwellian data. Both evaluations disagree within quoted uncertainties for fission and capture cross sections and total multiplicities of uranium isotopes. There are two factors, which may lead to such difference: Westcott g-factors with estimated 0.2% uncertainties used in the Axton's fit, and deviation of the thermal spectra from Maxwellian shape. To exclude or mitigate the impact of these factors, a new combined GMA fit of standards was undertaken with Axton's TNC evaluation based on 2200 m/s data used as a prior. New microscopic data at the thermal point, available since 1986, were added to the combined fit. Additionally, an independent evaluation of TNC was undertaken using CONRAD code. Both GMA and CONRAD results are consistent within quoted uncertainties. New evaluation shows a small increase of fission and capture thermal cross sections, and a corresponding decrease in evaluated thermal nubar for uranium isotopes and 239Pu.

  17. Dose calculation in brachytherapy with microcomputers

    International Nuclear Information System (INIS)

    Elbern, A.W.

    1989-01-01

    The computer algorithms, that allow the calculation of brachytherapy doses and its graphic representation for implants, using programs developed for Pc microcomputers are presented. These algorithms allow to localized the sources in space, from their projection in radiographics images and trace isodose counter. (C.G.C.) [pt

  18. SU-F-T-06: Development of a Formalism for Practical Dose Measurements in Brachytherapy in the German Standard DIN 6803

    Energy Technology Data Exchange (ETDEWEB)

    Hensley, F [Ruprecht Karl University of Heidelberg, Heidelberg (Germany); Chofor, N [Carl von Ossietzky University of Oldenburg, Oldenburg (Germany); Schoenfeld, A [University of Oldenburg, Oldenburg (Germany); Harder, D [Georg-August University of Goettingen, Goettingen (Germany)

    2016-06-15

    Purpose: In the steep dose gradients in the vicinity of a radiation source and due to the properties of the changing photon spectra, dose measurements in Brachytherapy usually have large uncertainties. Working group DIN 6803-3 is presently discussing recommendations for practical brachytherapy dosimetry incorporating recent theoretical developments in the description of brachytherapy radiation fields as well as new detectors and phantom materials. The goal is to prepare methods and instruments to verify dose calculation algorithms and for clinical dose verification with reduced uncertainties. Methods: After analysis of the distance dependent spectral changes of the radiation field surrounding brachytherapy sources, the energy dependent response of typical brachytherapy detectors was examined with Monte Carlo simulations. A dosimetric formalism was developed allowing the correction of their energy dependence as function of source distance for a Co-60 calibrated detector. Water equivalent phantom materials were examined with Monte Carlo calculations for their influence on brachytherapy photon spectra and for their water equivalence in terms of generating equivalent distributions of photon spectra and absorbed dose to water. Results: The energy dependence of a detector in the vicinity of a brachytherapy source can be described by defining an energy correction factor kQ for brachytherapy in the same manner as in existing dosimetry protocols which incorporates volume averaging and radiation field distortion by the detector. Solid phantom materials were identified which allow precise positioning of a detector together with small correctable deviations from absorbed dose to water. Recommendations for the selection of detectors and phantom materials are being developed for different measurements in brachytherapy. Conclusion: The introduction of kQ for brachytherapy sources may allow more systematic and comparable dose measurements. In principle, the corrections can be

  19. A Monte Carlo dosimetry study using Henschke applicator for cervical brachytherapy

    International Nuclear Information System (INIS)

    Yu, Pei-Chieh; Chao, Tsi-Chian; Lee, Chung-Chi; Wu, Ching-Jung; Tung, Chuan-Jong

    2010-01-01

    In recent years the Henschke applicator has been widely used for gynecologic patients treated by brachytherapy in Taiwan. However, the commercial brachytherapy planning system did not properly evaluate the dose perturbation caused by the Henschke applicator. Since the European Society for Therapeutic Radiology and Oncology advised that the effect of source shielding should be incorporated into the brachytherapy planning system, it required calculation and comparison of the dose distribution around the applicator. This study used the Monte Carlo MCNP code to simulate the dose distribution in a water phantom that contained the Henschke applicator with one tandem and two ovoids. Three dwell positions of a high dose rate 192 Ir source were simulated by including and excluding the applicator. The mesh tally option of the MCNP was applied to facilitate the calculation of a large number of tallies in the phantom. The voxel size effect and the charge particle equilibrium were studied by comparing the results calculated with different tally options. The calculated results showed that the brachytherapy planning system overestimated the rectal dose and that the shielding material in the applicator contributed more than 40% to the rectal dose.

  20. Prostate cancer brachytherapy

    International Nuclear Information System (INIS)

    Abreu, Carlos Eduardo Vita; Silva, Joao L. F.; Srougi, Miguel; Nesrallah, Adriano

    1999-01-01

    The transperineal brachytherapy with 125 I/Pd 103 seed implantation guided by transurethral ultrasound must be presented as therapeutical option of low urinary morbidity in patients with localized prostate cancer. The combined clinical staging - including Gleason and initial PSA - must be encouraged, for definition of a group of low risk and indication of exclusive brachytherapy. Random prospective studies are necessary in order to define the best role of brachytherapy, surgery and external beam radiation therapy

  1. Comparison between methods for fixing radioactive iodine in silver substrate for manufacturing brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Peleias Junior, Fernando S.; Zeituni, Carlos A.; Rostelato, Maria Elisa C.M., E-mail: fernandopeleias@gmail.com, E-mail: czeituni@ipen.br, E-mail: elisaros@ipen.br; and others

    2013-07-01

    Cancer is a term used generically to represent a group of more than 100 illnesses, including malignant tumors from different locations. According to World Health Organization (WHO), is a leading cause of death worldwide, accounted for 7.6 million deaths. Prostate cancer is the sixth most common type in the world, representing about 10% of all cases of cancer and its treatment may be by surgery, radiotherapy or even vigilant observation. A method of radiotherapy which has been extensively used in the early and intermediate stages of the illness is brachytherapy, where radioactive seeds are placed inside or next to the area requiring treatment, which reduces the probability of unnecessary damage to surrounding healthy tissues. Currently, the radioactive isotope Iodine-125, adsorbed on silver substrate, is one of the most used in prostate brachytherapy. The present study compares several deposition methods of radioactive Iodine on silver substrate, in order to choose the most suitable one to be implemented at the laboratory of radioactive sources production of IPEN. The methodology used was chosen based on the available infrastructure and experience of the researchers of the institute. Therefore, Iodine-131 was used for testing (same chemical behavior of Iodine -125). Three methods were selected: method 1 (test based on electrodeposition method, developed by David Kubiatowicz) which presented efficiency of 65.16% ; method 2 (chemical reaction based on the method developed by David Kubiatowicz -HCl) which presented efficiency of 70.80%; method 3 (chemical reaction based on the method developed by Dr. Maria Elisa Rostelato) which presented efficiency of 55.80% . Based on the results, the second method is the suggested one to be implemented at the laboratory of radioactive sources production of IPEN. (author)

  2. Comparison between methods for fixing radioactive iodine in silver substrate for manufacturing brachytherapy sources

    International Nuclear Information System (INIS)

    Peleias Junior, Fernando S.; Zeituni, Carlos A.; Rostelato, Maria Elisa C.M.

    2013-01-01

    Cancer is a term used generically to represent a group of more than 100 illnesses, including malignant tumors from different locations. According to World Health Organization (WHO), is a leading cause of death worldwide, accounted for 7.6 million deaths. Prostate cancer is the sixth most common type in the world, representing about 10% of all cases of cancer and its treatment may be by surgery, radiotherapy or even vigilant observation. A method of radiotherapy which has been extensively used in the early and intermediate stages of the illness is brachytherapy, where radioactive seeds are placed inside or next to the area requiring treatment, which reduces the probability of unnecessary damage to surrounding healthy tissues. Currently, the radioactive isotope Iodine-125, adsorbed on silver substrate, is one of the most used in prostate brachytherapy. The present study compares several deposition methods of radioactive Iodine on silver substrate, in order to choose the most suitable one to be implemented at the laboratory of radioactive sources production of IPEN. The methodology used was chosen based on the available infrastructure and experience of the researchers of the institute. Therefore, Iodine-131 was used for testing (same chemical behavior of Iodine -125). Three methods were selected: method 1 (test based on electrodeposition method, developed by David Kubiatowicz) which presented efficiency of 65.16% ; method 2 (chemical reaction based on the method developed by David Kubiatowicz -HCl) which presented efficiency of 70.80%; method 3 (chemical reaction based on the method developed by Dr. Maria Elisa Rostelato) which presented efficiency of 55.80% . Based on the results, the second method is the suggested one to be implemented at the laboratory of radioactive sources production of IPEN. (author)

  3. Investigation of Anisotropy Caused by Cylinder Applicator on Dose Distribution around Cs-137 Brachytherapy Source using MCNP4C Code

    Directory of Open Access Journals (Sweden)

    Sedigheh Sina

    2011-06-01

    Full Text Available Introduction: Brachytherapy is a type of radiotherapy in which radioactive sources are used in proximity of tumors normally for treatment of malignancies in the head, prostate and cervix. Materials and Methods: The Cs-137 Selectron source is a low-dose-rate (LDR brachytherapy source used in a remote afterloading system for treatment of different cancers. This system uses active and inactive spherical sources of 2.5 mm diameter, which can be used in different configurations inside the applicator to obtain different dose distributions. In this study, first the dose distribution at different distances from the source was obtained around a single pellet inside the applicator in a water phantom using the MCNP4C Monte Carlo code. The simulations were then repeated for six active pellets in the applicator and for six point sources.  Results: The anisotropy of dose distribution due to the presence of the applicator was obtained by division of dose at each distance and angle to the dose at the same distance and angle of 90 degrees. According to the results, the doses decreased towards the applicator tips. For example, for points at the distances of 5 and 7 cm from the source and angle of 165 degrees, such discrepancies reached 5.8% and 5.1%, respectively.  By increasing the number of pellets to six, these values reached 30% for the angle of 5 degrees. Discussion and Conclusion: The results indicate that the presence of the applicator causes a significant dose decrease at the tip of the applicator compared with the dose in the transverse plane. However, the treatment planning systems consider an isotropic dose distribution around the source and this causes significant errors in treatment planning, which are not negligible, especially for a large number of sources inside the applicator.

  4. Imaging of fast-neutron sources using solid-state track-recorder pinhole radiography

    International Nuclear Information System (INIS)

    Ruddy, F.H.; Gold, R.; Roberts, J.H.; Kaiser, B.J.; Preston, C.C.

    1983-08-01

    Pinhole imaging methods are being developed and tested for potential future use in imaging the intense neutron source of the Fusion Materials Irradiation Test (FMIT) Facility. Previously reported, extensive calibration measurements of the proton, neutron, and alpha particle response characteristics of CR-39 polymer solid state track recorders (SSTRs) are being used to interpret the results of imaging experiments using both charged particle and neutron pinhole collimators. High resolution, neutron pinhole images of a 252 Cf source have been obtained in the form of neutron induced proton recoil tracks in CR-39 polymer SSTR. These imaging experiments are described as well as their potential future applications to FMIT

  5. Evaluation of high-energy brachytherapy source electronic disequilibrium and dose from emitted electrons.

    Science.gov (United States)

    Ballester, Facundo; Granero, Domingo; Pérez-Calatayud, José; Melhus, Christopher S; Rivard, Mark J

    2009-09-01

    The region of electronic disequilibrium near photon-emitting brachytherapy sources of high-energy radionuclides (60Co, 137CS, 192Ir, and 169Yb) and contributions to total dose from emitted electrons were studied using the GEANT4 and PENELOPE Monte Carlo codes. Hypothetical sources with active and capsule materials mimicking those of actual sources but with spherical shape were examined. Dose contributions due to source photons, x rays, and bremsstrahlung; source beta-, Auger electrons, and internal conversion electrons; and water collisional kerma were scored. To determine if conclusions obtained for electronic equilibrium conditions and electron dose contribution to total dose for the representative spherical sources could be applied to actual sources, the 192Ir mHDR-v2 source model (Nucletron B.V., Veenendaal, The Netherlands) was simulated for comparison to spherical source results and to published data. Electronic equilibrium within 1% is reached for 60Co, 137CS, 192Ir, and 169Yb at distances greater than 7, 3.5, 2, and 1 mm from the source center, respectively, in agreement with other published studies. At 1 mm from the source center, the electron contributions to total dose are 1.9% and 9.4% for 60Co and 192Ir, respectively. Electron emissions become important (i.e., > 0.5%) within 3.3 mm of 60Co and 1.7 mm of 192Ir sources, yet are negligible over all distances for 137Cs and 169Yb. Electronic equilibrium conditions along the transversal source axis for the mHDR-v2 source are comparable to those of the spherical sources while electron dose to total dose contribution are quite different. Electronic equilibrium conditions obtained for spherical sources could be generalized to actual sources while electron contribution to total dose depends strongly on source dimensions, material composition, and electron spectra.

  6. 48 CFR 53.301-252 - Standard Form 252, Architect-Engineer Contract.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Standard Form 252, Architect-Engineer Contract. 53.301-252 Section 53.301-252 Federal Acquisition Regulations System FEDERAL..., Architect-Engineer Contract. EC01MY91.035 EC01MY91.036 ...

  7. Dose reduction in LDR brachytherapy by implanted prostate gold fiducial markers.

    Science.gov (United States)

    Landry, Guillaume; Reniers, Brigitte; Lutgens, Ludy; Murrer, Lars; Afsharpour, Hossein; de Haas-Kock, Danielle; Visser, Peter; van Gils, Francis; Verhaegen, Frank

    2012-03-01

    The dosimetric impact of gold fiducial markers (FM) implanted prior to external beam radiotherapy of prostate cancer on low dose rate (LDR) brachytherapy seed implants performed in the context of combined therapy was investigated. A virtual water phantom was designed containing a single FM. Single and multi source scenarios were investigated by performing Monte Carlo dose calculations, along with the influence of varying orientation and distance of the FM with respect to the sources. Three prostate cancer patients treated with LDR brachytherapy for a recurrence following external beam radiotherapy with implanted FM were studied as surrogate cases to combined therapy. FM and brachytherapy seeds were identified on post implant CT scans and Monte Carlo dose calculations were performed with and without FM. The dosimetric impact of the FM was evaluated by quantifying the amplitude of dose shadows and the volume of cold spots. D(90) was reported based on the post implant CT prostate contour. Large shadows are observed in the single source-FM scenarios. As expected from geometric considerations, the shadows are dependent on source-FM distance and orientation. Large dose reductions are observed at the distal side of FM, while at the proximal side a dose enhancement is observed. In multisource scenarios, the importance of shadows appears mitigated, although FM at the periphery of the seed distribution caused underdosage (LDR brachytherapy seed implant dose distributions. Therefore, reduced tumor control could be expected from FM implanted in tumors, although our results are too limited to draw conclusions regarding clinical significance.

  8. Prototypes of phosphorus-32 sealed sources for use in Brachytherapy

    International Nuclear Information System (INIS)

    Anaya Garro, Olgger; Vela Mora, Mariano; Revilla Silva, Angel Revilla

    2005-01-01

    It has developed prototypes of phosphorus-32 sealed sources for use in Brachytherapy. This one was made in two stages, at the first one, we designed and constructed the container (capsule), the filling system and the sealed system; at the second one, we made the irradiation of the capsules containing the 'target'. The prototypes was made of aluminum in cylindrical geometry. During the irradiation test was made using two different dimensions: one of 1 mm outer diameter and 1 cm length and another one of 0.8 mm outer diameter and 5 mm length. They were radiated in the core of the RP-10 research reactor, at 7.93 x10 13 n/cm 2 .s thermal neutron flux during 27 operation cycles. Activities of 144.53 MBq (3.91 mCi) and 107.67 MBq (2.91 mCi) was obtained for each case. This activities are adequate to restenosis and for some tumors treatment. We can observed that the capsules irradiated passed visual inspection in its physical integrity (leakage and geometry). It has been demonstrated, that the beta radiation for his minor power of penetration and its high interaction, causes major local damage to the malignant tissue, minimizing the damage of the healthy surrounding tissues. It has been advisable to use for the treatment of illnesses of the circulatory system and some tumors. At the present, the source of strontium-90 are the most beta ray source used, but of this one are obtained as fission product of uranium target, where valuable radioactive waste is generated, whereas if we were using phosphorus-32 that we propose, radioactive waste would not be generated since it would take place directly as sealed source, for reaction (n, β). (author)

  9. SU-E-T-284: Revisiting Reference Dosimetry for the Model S700 Axxent 50 KV{sub p} Electronic Brachytherapy Source

    Energy Technology Data Exchange (ETDEWEB)

    Hiatt, JR [Rhode Island Hospital, Providence, RI (United States); Rivard, MJ [Tufts University School of Medicine, Boston, MA (United States)

    2014-06-01

    Purpose: The model S700 Axxent electronic brachytherapy source by Xoft was characterized in 2006 by Rivard et al. The source design was modified in 2006 to include a plastic centering insert at the source tip to more accurately position the anode. The objectives of the current study were to establish an accurate Monte Carlo source model for simulation purposes, to dosimetrically characterize the new source and obtain its TG-43 brachytherapy dosimetry parameters, and to determine dose differences between the source with and without the centering insert. Methods: Design information from dissected sources and vendor-supplied CAD drawings were used to devise the source model for radiation transport simulations of dose distributions in a water phantom. Collision kerma was estimated as a function of radial distance, r, and polar angle, θ, for determination of reference TG-43 dosimetry parameters. Simulations were run for 10{sup 10} histories, resulting in statistical uncertainties on the transverse plane of 0.03% at r=1 cm and 0.08% at r=10 cm. Results: The dose rate distribution the transverse plane did not change beyond 2% between the 2006 model and the current study. While differences exceeding 15% were observed near the source distal tip, these diminished to within 2% for r>1.5 cm. Differences exceeding a factor of two were observed near θ=150° and in contact with the source, but diminished to within 20% at r=10 cm. Conclusions: Changes in source design influenced the overall dose rate and distribution by more than 2% over a third of the available solid angle external from the source. For clinical applications using balloons or applicators with tissue located within 5 cm from the source, dose differences exceeding 2% were observed only for θ>110°. This study carefully examined the current source geometry and presents a modern reference TG-43 dosimetry dataset for the model S700 source.

  10. [An improved method of preparing protein and peptide probes in mass spectrometry with ionization of division fragments by californium-252 (TOF-PDMS)].

    Science.gov (United States)

    Chivanov, V D; Zubarev, R A; Aksenov, S A; Bordunova, O G; Eremenko, V I; Kabanets, V M; Tatarinova, V I; Mishnev, A K; Kuraev, V V; Knysh, A N; Eremenko, I A

    1996-08-01

    The addition of organic acids (picric, oxalic, citric, or tartaric) to peptide and protein samples was found to significantly increase the yield of their quasi-molecular ions (QMI) in time-of-flight 252Cf plasma desorption mass spectrometry. The yield of the ions depended on the pKa of the acid added.

  11. Dose rate constants for 125I, 103Pd, 192Ir and 169Yb brachytherapy sources: an EGS4 Monte Carlo study

    International Nuclear Information System (INIS)

    Mainegra, Ernesto; Capote, Roberto; Lopez, Ernesto

    1998-01-01

    An exhaustive revision of dosimetry data for 192 Ir, 125 I, 103 Pd and 169 Yb brachytherapy sources has been performed by means of the EGS4 simulation system. The DLC-136/PHOTX cross section library, water molecular form factors, bound Compton scattering and Doppler broadening of the Compton-scattered photon energy were considered in the calculations. The absorbed dose rate per unit contained activity in a medium at 1 cm in water and air-kerma strength per unit contained activity for each seed model were calculated, allowing the dose rate constant (DRC) Λ to be estimated. The influence of the calibration procedure on source strength for low-energy brachytherapy seeds is discussed. Conversion factors for 125 I and 103 Pd seeds to obtain the dose rate in liquid water from the dose rate measured in a solid water phantom with a detector calibrated for dose to water were calculated. A theoretical estimate of the DRC for a 103 Pd model 200 seed equal to 0.669±0.002 cGy h -1 U -1 is obtained. Comparison of obtained DRCs with measured and calculated published results shows agreement within 1.5% for 192 Ir, 169 Yb and 125 I sources. (author)

  12. Methodology study for fixation of radioactive iodine in polymeric substrate for brachytherapy sources

    International Nuclear Information System (INIS)

    Rodrigues, Bruna T.; Rostelato, Maria Elisa C.M.; Souza, Carla D.; Tiezzi, Rodrigo; Souza, Daiane B. de; Benega, Marcos A.G.; Souza, Anderson S. de; Peleias Junior, Fernando S.; Zeituni, Calos A.; Fernandes, Vagner; Melo, Emerson Ronaldo de; Camargo, Anderson Rogerio de

    2015-01-01

    Cancer is now the second leading cause of death by disease in several countries, including Brazil. Prostate cancer is the most common among men. Brachytherapy is a modality of radiotherapy in which radioactive seeds are placed inside or in contact with the organ to be treated. The most widely used radioisotope in prostate brachytherapy is Iodine-125 which is presented fixated on a silver substrate that is subsequently placed inside a titanium capsule. A large dose of radiation is released only in the targeted tumor protecting healthy surrounding tissues. The technique requires the application of 80 - 120 seeds per patient. The implants of seeds have low impact and non-surgical procedures. Most patients can return to normal life within three days with little or no pain. This work proposes an alternative to the seeds that have already been developed, in order to reduce the cost by obtaining a better efficiency on fixing the radioactive iodine onto the epoxy resin. Methods have been developed to perform the fixation of Iodine-125 onto polymeric substrates. The parameters analyzed were the immersion time, type of static or dynamic reaction, concentration of the adsorption solution, the specific activity of the radioactive source, the need for carrier and chemical form of the radioactive Iodine. These experiments defined the most effective method to fixate the Iodine onto the polymeric material (epoxy resin), the Iodine activity in the polymeric substrate, the activity of the distribution of variation in a plot of polymeric cores and the efficiency of the epoxy resin to seal the seed. (author)

  13. Low dose rate 137Cs Brachytherapy source calibration with farmer type ionisation chamber and specialised fabricated jig in Korle-Bu Teaching Hospital

    International Nuclear Information System (INIS)

    Opare-Asare, K.

    2013-06-01

    An important part of a general quality assurance (QA) program for brachytherapy dosimetry is the source calibration because wide ranges of uncertainties are quoted by manufactures. This research is aimed at calibrating LDR 137 Cs brachytherapy source in the Korle-Bu Teaching Hospital by multiple-distance air kerma measurement technique using a specialized designed jig and a calibrated therapy ionization chamber. Specialized jig was fabricated with source holder positions and ionization chamber positions on the jig. Farmer type ionization chamber of volume 0.6cm 3 was used with and without build up cap. The results were validated using well type ionization chamber on channels on 1 and 5 taking into account decay correction. Air Kerma rates were determined at multiple distances between 8cm to 12cm from measured charges recorded by Max 4000 electrometer. The scatter dose relationship described by Ezzell [1992] was used to determine scattered radiation. The analytical method of determining air kerma calibration factor of 137 Cs described by Sharma et.al [2011] was used to determine beam quality correction factor for the 137 Cs. Beam attenuation was determined. Experimental data were compared with manufacturer's quoted source strength for verification. Well type ionization chamber results and experimental results on channel V1 and V5 deviated by 2.39% and 1.58% respectively. Experimental data deviated by 4.73% and 1.24% from theoretical data on channels V1 and V5 respectively. The mean of the experimental data deviated from the theoretical data by ±3.1% and from the well type measurements data by ±1.98%. The well type chamber results compared well with the experimental data. This is an indication that the method used for source calibration is a reliable alternative method of source calibration. The method used in this work has proven to be an efficient way of determining the actual source strength of the LDR brachytherapy 137 Cs source in Korle-Bu Radiotherapy Centre

  14. Quality control of Ir-192, Cs-137 and Ra-226 sources for use in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Oyrzun Cortes, C H; Palma D, A M; Penaloza C, H; Tomicic, M [Comision Chilena de Energia Nuclear, Santiago (Chile)

    1996-08-01

    In order to establish a certain degree of reliability in the use and managing of radioactive material in brachytherapy, a minimal quality control to each source was implemented. The purpose was to estimate the degree of radioactive leak, resistance to the mechanic traction and stress of use. Through a physical control of the radioactive material (a simple dip test and using a photon scanner or auto-radiography) the minimal conditions that guarantee safe use are established. This information is transmitted to a calibration laboratory for certification in exposure rate and/or activity. Systematic use of these tests, enables discovery of radioactive material leakage due to faults in the seal. (author).

  15. Quality control of Ir-192, Cs-137 and Ra-226 sources for use in brachytherapy

    International Nuclear Information System (INIS)

    Oyrzun Cortes, C.H.; Palma D, A.M.; Penaloza C, H.; Tomicic, M.

    1996-01-01

    In order to establish a certain degree of reliability in the use and managing of radioactive material in brachytherapy, a minimal quality control to each source was implemented. The purpose was to estimate the degree of radioactive leak, resistance to the mechanic traction and stress of use. Through a physical control of the radioactive material (a simple dip test and using a photon scanner or auto-radiography) the minimal conditions that guarantee safe use are established. This information is transmitted to a calibration laboratory for certification in exposure rate and/or activity. Systematic use of these tests, enables discovery of radioactive material leakage due to faults in the seal. (author)

  16. Neutron Sources for Standard-Based Testing

    Energy Technology Data Exchange (ETDEWEB)

    Radev, Radoslav [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McLean, Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-10

    The DHS TC Standards and the consensus ANSI Standards use 252Cf as the neutron source for performance testing because its energy spectrum is similar to the 235U and 239Pu fission sources used in nuclear weapons. An emission rate of 20,000 ± 20% neutrons per second is used for testing of the radiological requirements both in the ANSI standards and the TCS. Determination of the accurate neutron emission rate of the test source is important for maintaining consistency and agreement between testing results obtained at different testing facilities. Several characteristics in the manufacture and the decay of the source need to be understood and accounted for in order to make an accurate measurement of the performance of the neutron detection instrument. Additionally, neutron response characteristics of the particular instrument need to be known and taken into account as well as neutron scattering in the testing environment.

  17. Preparations for the start-up of a research program in nuclear safeguards at Chalmers

    Energy Technology Data Exchange (ETDEWEB)

    Avdic, Senada; Pazsit, Imre

    2004-03-01

    The Department of Reactor Physics at Chalmers University of Technology plans to start-up a research program in nuclear safeguards and nuclear material management. The program is aimed at utilizing the experimental facilities as well as the experience in reactor physics, criticality safety, signal processing and unfolding, and experimental nuclear techniques, in tackling problems in non-destructive assay (NDA) of nuclear materials. For the introductory part of this program, support has been received from the Swedish Nuclear Power Inspectorate to host Dr. Senada Avdic, University of Tuzla, Bosnia, as a post-doc for three months to participate in the preparatory program. The preparations were focussed on a survey of existing active non-destructive assay methods and preparations of their application in the experimental and theoretical/calculational research of our Department. The methods surveyed comprise - the use of a {sup 252}Cf source in active NDA measurements; - planning of an experiment with the existing equipments of the Department; - time correlation measurements with a {sup 252}Cf source and/or a {sup 252}Cf detector; - Monte Carlo simulations of the time correlations between gammas and neutrons from a measurement with a {sup 252}Cf detector: the MCNP-PoliMi code; - Identification of fissile material (enrichment/mass) with {sup 252}Cf measurements; the use of various unfolding techniques (artificial neural networks) for identifying nuclear parameters; use of neutron activation analysis with a neutron generator for determination of distribution of material in an unknown sample; - determination of fissile material content by measurements of delayed neutrons.

  18. Prostate brachytherapy seed migration to the heart seen on cardiovascular computed tomographic angiography

    Directory of Open Access Journals (Sweden)

    Shilpa Sachdeva, MD

    2017-03-01

    Full Text Available Brachytherapy consists of placing radioactive sources into or adjacent to tumors, to deliver conformal radiation treatment. The technique is used for treatment of primary malignancies and for salvage in recurrent disease. Permanent prostate brachytherapy seeds are small metal implants containing radioactive sources of I-125, Pd-103, or Cs-131 encased in a titanium shell. They can embolize through the venous system to the lungs or heart and subsequently be detected by cardiovascular computed tomography. Cardiovascular imagers should be aware of the appearance of migrated seeds, as their presence in the chest is generally benign, so that unnecessary worry and testing are avoided. We report a case of a patient who underwent brachytherapy for prostate cancer and developed a therapeutic seeds embolus to the right ventricle.

  19. Overview of NWIS Software

    International Nuclear Information System (INIS)

    Mullens, J.A.

    1999-01-01

    The Nuclear Weapons Identification System (NWIS) is a system that performs radiation signature measurements on objects such as nuclear weapons components. NWIS consists of a 252 Cf fission source, radiation detectors and associated analog electronics, data acquisition boards, and a computer running Windows NT and the application software. NWIS uses signal processing techniques to produce a radiation signature from the radiation emitted from the object. This signature can be stored and later compared to another signature to determine whether two objects are similar. A library of such signatures can be used to identify objects in closed containers as well as determine attributes such as fissile mass and in some cases enrichment. NWIS uses a 252 Cf source on one side of the object to produce radiation that its detectors measure on the other side of the target (active mode). If the object naturally emits enough radiation, the 252 Cf source is not required (passive mode). The NWIS data acquisition hardware has five detector channels. Each channel receives shaped detector pulses and times those pulses with 1 nanosecond resolution. In active mode measurements one of these channels receives pulses from a detector measuring the 252 Cf source fissions. Thus, for active mode measurements, NWIS has the time of each 252 Cf fission and the subsequent injection of neutrons and gamma rays into the object. The remaining channels receive pulses from the detectors measuring radiation from the object. These detectors record the amount and time of radiation exiting the object. By correlating the radiation events among the source and the other detectors, and among the detectors themselves, a characteristic response of the object to 252 Cf radiation or its own internal radiation is measured. The data acquisition hardware consists of two custom-made boards. The Data Capture and Compression (DCC) board is built around a Gallium Arsine (GaAs) chip designed at ORNL. This chip assigns a time

  20. SU-E-T-212: Comparison of TG-43 Dosimetric Parameters of Low and High Energy Brachytherapy Sources Obtained by MCNP Code Versions of 4C, X and 5

    Energy Technology Data Exchange (ETDEWEB)

    Zehtabian, M; Zaker, N; Sina, S [Shiraz University, Shiraz, Fars (Iran, Islamic Republic of); Meigooni, A Soleimani [Comprehensive Cancer Center of Nevada, Las Vegas, Nevada (United States)

    2015-06-15

    Purpose: Different versions of MCNP code are widely used for dosimetry purposes. The purpose of this study is to compare different versions of the MCNP codes in dosimetric evaluation of different brachytherapy sources. Methods: The TG-43 parameters such as dose rate constant, radial dose function, and anisotropy function of different brachytherapy sources, i.e. Pd-103, I-125, Ir-192, and Cs-137 were calculated in water phantom. The results obtained by three versions of Monte Carlo codes (MCNP4C, MCNPX, MCNP5) were compared for low and high energy brachytherapy sources. Then the cross section library of MCNP4C code was changed to ENDF/B-VI release 8 which is used in MCNP5 and MCNPX codes. Finally, the TG-43 parameters obtained using the MCNP4C-revised code, were compared with other codes. Results: The results of these investigations indicate that for high energy sources, the differences in TG-43 parameters between the codes are less than 1% for Ir-192 and less than 0.5% for Cs-137. However for low energy sources like I-125 and Pd-103, large discrepancies are observed in the g(r) values obtained by MCNP4C and the two other codes. The differences between g(r) values calculated using MCNP4C and MCNP5 at the distance of 6cm were found to be about 17% and 28% for I-125 and Pd-103 respectively. The results obtained with MCNP4C-revised and MCNPX were similar. However, the maximum difference between the results obtained with the MCNP5 and MCNP4C-revised codes was 2% at 6cm. Conclusion: The results indicate that using MCNP4C code for dosimetry of low energy brachytherapy sources can cause large errors in the results. Therefore it is recommended not to use this code for low energy sources, unless its cross section library is changed. Since the results obtained with MCNP4C-revised and MCNPX were similar, it is concluded that the difference between MCNP4C and MCNPX is their cross section libraries.