WorldWideScience

Sample records for epithermal neutrons activation

  1. Epithermal neutron activation analysis of food

    International Nuclear Information System (INIS)

    Zikovsky, L.; Soliman, K.

    1999-01-01

    Food samples were irradiated with thermal and epithermal neutrons. The average ratios of thermal to epithermal activity were determined for 80 Br, 49 Ca, 38 Cl, 60m Co, 42 K, 27 Mg, 56 Mn, 24 Na, and 86m Rb. They were equal to 2.1, 26, 24, 6.6, 19, 16, 11, 23 and 1.9, respectively. Then, 57 food samples were analyzed by epithermal neutron activation analysis for Br and Rb. The concentrations (in ppm) of Br and Rb were in asparagus (2) 2.3, 11.5; beets (3) 0.5, 0.8; beef (3) 1.7, 3.6; cabbage (5) 0.5, 10.8; carrot (3) 0.2, 3.7; chicken (3) 0.6, 4.4; chocolate (7) 11.1, 18.7; egg (3) 0.9, 1.9; french bean (3) 0.3, 1.0; goose (2) 1.3, 9.3; lettuce (2) 0.9, 1.7; pork (1) 1.5, 4.4; potato (7) 1.0, 1.2; sausage (3) 4.8, 3.5; spinach (3) 3.6, 4.0; strawberry jam (3) 0.4, 1.4; tomato (1) 13.5, 14.6; turkey (3) 1.2, 4.9. respectively. The number of samples and analyzed is indicated in parentheses. (author)

  2. Epithermal neutron activation analysis in applied microbiology

    International Nuclear Information System (INIS)

    Marina Frontasyeva

    2012-01-01

    Some results from applying epithermal neutron activation analysis at FLNP JINR, Dubna, Russia, in medical biotechnology, environmental biotechnology and industrial biotechnology are reviewed. In the biomedical experiments biomass from the blue-green alga Spirulina platensis (S. platensis) has been used as a matrix for the development of pharmaceutical substances containing such essential trace elements as selenium, chromium and iodine. The feasibility of target-oriented introduction of these elements into S. platensis biocomplexes retaining its protein composition and natural beneficial properties was shown. The absorption of mercury on growth dynamics of S. platensis and other bacterial strains was observed. Detoxification of Cr and Hg by Arthrobacter globiformis 151B was demonstrated. Microbial synthesis of technologically important silver nanoparticles by the novel actinomycete strain Streptomyces glaucus 71 MD and blue-green alga S. platensis were characterized by a combined use of transmission electron microscopy, scanning electron microscopy and energy-dispersive analysis of X-rays. It was established that the tested actinomycete S. glaucus 71 MD produces silver nanoparticles extracellularly when acted upon by the silver nitrate solution, which offers a great advantage over an intracellular process of synthesis from the point of view of applications. The synthesis of silver nanoparticles by S. platensis proceeded differently under the short-term and long-term silver action. (author)

  3. Determination of silver using cyclic epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Pun, T.H.; Landsberger, S.

    2012-01-01

    A fast pneumatic transfer facility was installed in Nuclear Engineering Teaching Laboratory (NETL) of the University of Texas at Austin for the purpose of cyclic thermal and epithermal neutron activation analysis. In this study efforts were focused on the evaluation of cyclic epithermal neutron activation analysis (CENAA). Various NIST and CANMET certified materials were analyzed by the system. Experiment results showed 110 Ag with its 25 s half-life as one of the isotopes favored by the system. Thus, the system was put into practical application in identifying silver in metallic ores. Comparison of sliver concentrations as determined by CENAA in CANMET certified reference materials gave very good results. (author)

  4. Epithermal neutron activation analysis using a boron carbide irradiation filter

    International Nuclear Information System (INIS)

    Ehmann, W.D.; Brueckner, J.

    1980-01-01

    The use of boron carbide as a thermal neutron filter in epithermal neutron activation (ENAA) analysis has been investigated. As compared to the use of a cadmium filter, boron provides a greater reduction of activities from elements relatively abundant in terrestrial rocks and fossil fuels, such as Na, La, Sc and Fe. These elements have excitation functions which follow the 1/v law in the 1 to 10 eV lower epithermal region. This enhances the sensitivity of ENAA for elements such as U, Th, Ba and etc. which have strong resonances in the higher epithermal region above 10 eV. In addition, a boron carbide filter has the advantages over cadmium of acquiring a relatively low level of induced activity which poses minimal radiation safety problems, when used for ENAA. (author)

  5. Directional epithermal neutron detector

    International Nuclear Information System (INIS)

    Givens, W.W.; Mills, W.R. Jr.

    1986-01-01

    A borehole tool for epithermal neutron die-away logging of subterranean formations surrounding a borehole is described which consists of: (a) a pulsed source of fast neutrons for irradiating the formations surrounding a borehole, (b) at least one neutron counter for counting epithermal neutrons returning to the borehole from the irradiated formations, (c) a neutron moderating material, (d) an outer thermal neutron shield providing a housing for the counter and the moderating material, (e) an inner thermal neutron shield dividing the housing so as to provide a first compartment bounded by the inner thermal neutron shield and a first portion of the outer thermal neutron shield and a second compartment bounded by the inner thermal neutron shield and a second portion of the outer thermal neutron shield, the counter being positioned within the first compartment and the moderating material being positioned within the second compartment, and (f) means for positioning the borehole tool against one side of the borehole wall and azimuthally orienting the borehole tool such that the first chamber is in juxtaposition with the borehole wall, the formation epithermal neutrons penetrating into the first chamber through the first portion of the outer thermal neutron shield are detected by the neutron counter for die-away measurement, thereby maximizing the directional sensitivty of the neutron counter to formation epithermal neutrons, the borehole fluid epithermal neutrons penetrating into the second chamber through the second chamber through the second portion of the outer thermal neutron shield are largely slowed down and lowered in energy by the moderating material and absorbed by the inner thermal neutron shield before penetrating into the first chamber, thereby minimizing the directional sensitivity of the neutron counter to borehole fluid epithermal neutrons

  6. Epithermal Neutron Activation Analysis of the Asian Herbal Plants

    International Nuclear Information System (INIS)

    Baljinnyam, N.; Frontasyeva, M. V.; Ostrovnaya, T. M.; Pavlov, S. S.; Jugder, B.; Norov, N.

    2011-01-01

    Asian medicinal herbs Chrysanthemum (Spiraea aquilegifolia Pall.) and Red Sandalwood (Pterocarpus Santalinus) are widely used in folk and Ayurvedic medicine for healing and preventing some diseases. The modern medical science has proved that the Chrysanthemum (Spiraea aquilegifolia Pall.) possesses the following functions: reducing blood press, dispelling cancer cell, coronary artery's expanding and bacteriostating and Red Sandalwood (Pterocarpus Santalinus) is recommended against headache, toothache, skin diseases, vomiting and sometimes it is taken for treatment of diabetes. Species of Chrysanthemums were collected in the north-eastern and central Mongolia, and the Red Sandalwood powder was imported from India. Samples of Chrysanthemums (branches, flowers and leaves)(0.5 g) and red sandalwood powder (0.5 g) were subjected to the multi-element instrumental neutron activation analysis using epithermal neutrons (ENAA) at the IBR-2 reactor, Frank Laboratory of Neutron Physics (FLNP) JINR, Dubna. A total of 41 elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Cd, Cs, Ba, La, Hf, Ta, W, Sb, Au, Hg, Ce, Nd, Sm, Eu, Tb, Dy, Yb, Th, U, Lu) were determined. For the first time such a large group of elements was determined in the herbal plants used in Mongolia. The quality control of the analytical results was provided by using certified reference material Bowen Cabbage. The results obtained are compared to the ''Reference plant? data (B. Markert, 1992) and interpreted in terms of excess of such elements as Se, Cr, Ca, Fe, Ni, Mo, and rare earth elements.

  7. Epithermal neutron activation analysis for studying the environment

    International Nuclear Information System (INIS)

    Frontas'eva, M.V.; Steinnes, E.

    1997-01-01

    Epithermal neutron activation analysis (ENAA) has certain advantages over the conventional instrumental analysis (INAA) in terms of improvement in precision and lowering of detection limits, reduction of high matrix activity and fission interferences if any. The current status and the applications of ENAA to environmental samples are reviewed. Experience in the use of ENAA in the monitoring of atmospheric depositions by means of moss-biomonitors at pulsed fast reactor IBR-2 in Dubna is summarized. INAA has shown to be useful for a number of sample types of interest in environmental studies, and should find more extensive use in this area. Analysis of airborne particulate matter is a case where ENAA should be particularly useful. A similar case where ENAA has shown strong performance is in the analysis of mosses used as biomonitors of atmospheric deposition, where 45 elements were determined. In this and other cases, however, induction-coupled plasma mass spectrometry is a very strong competitor, offering data for even more elements. A comparison of ENAA and ICP-MS for moss analysis is presented, and cases where ENAA is unique are discussed

  8. Uranium in coral skeletons determined by epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Ohde, S.; Hossain, M.M.M.; Ozaki, H.; Masuzawa, T.

    2003-01-01

    A simple and non-destructive method has been proposed for the routine determination of uranium by epithermal neutron activation analysis in coral skeletons. Using a cadmium capsule, about 0.1-0.2 g samples were irradiated for 6 hours in the Triga Mark II Reactor. Measurements of γ-ray ( 239 Np via 239 U) were performed with each sample and standard after cooling for about three days. Compared with a non-destructive thermal NAA, the present method was found to improve the sensitivity because it reduced the intense Compton background induced by 24 Na. Uranium in coral standards was determined within 2% of analytical precision. The data obtained for the carbonate standards are mostly consistent with reported values. The present method could be usefully applied to determine uranium contents in fossil corals from the Funafuti Atoll in the Pacific. The distribution of uranium between seawater and coral skeletons is also discussed in order to understand the environmental media in which the coral grew. (author)

  9. Optimization in Activation Analysis by Means of Epithermal Neutrons. Determination of Molybdenum in Steel

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D; Jirlow, J

    1963-12-15

    Optimization in activation analysis by means of selective activation with epithermal neutrons is discussed. This method was applied to the determination of molybdenum in a steel alloy without recourse to radiochemical separations. The sensitivity for this determination is estimated to be 10 ppm. With the common form of activation by means of thermal neutrons, the sensitivity would be about one-tenth of this. The sensitivity estimations are based on evaluation of the photo peak ratios of Mo-99/Fe-59.

  10. Epithermal neutron flux characterization of the TRIGA Mark III reactor, Salazar, Mexico, for use in Internal Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Diaz Rizo, O.; Herrera Peraza, E.

    1996-01-01

    The non ideality of the epithermal neutron flux distribution at a reactor site parameter (made, using Chloramine-T method. Radiochemical purity and stability of the labelled product were determined by radiochromatography. The labelled Melagenine-II showed two radioactive fractions thermal-to-epithermal neutron ratio (f) were determined in the 3 typical irradiations positions of the TRIGA Mark III reactor of the National Nuclear Research Institute, Salazar, Mexico, using the Cd-ratio for multi monitor and bare bi-isotopic monitor methods respectively. This characterization is of use in the K o - method of neutron activation analysis, recently introduced at the Institute

  11. Measurement of thermal, epithermal and fast neutrons fluxes by the activation foil method at IEA-R1 reactor

    International Nuclear Information System (INIS)

    Dias, M.S.; Koskinas, M.F.; Berretta, J.R.; Fratin, L.; Botelho, S.

    1990-01-01

    The thermal, epithermal and fast neutron fluxes have been determined experimentally by the activation foil method at position GI, located near the IEA-R1 reactor core. The reactions used were 197 Au (n,gamma) 198 Au, for thermal and epithermal neutrons and 27 Na (n,alpha) 24 Na, for fast neutrons. The activities were measured by the 4π(PC)β-γ coincidence method. (author)

  12. Epithermal neutron instrumentation at ISIS

    International Nuclear Information System (INIS)

    Gorini, G; Festa, G; Andreani, C

    2014-01-01

    The advent of pulsed neutron sources makes available high epithermal neutron fluxes (in the energy range between 500 meV and 100 eV). New dedicated instrumentation, such as Resonance Detectors, was developed at ISIS spallation neutron source in the last years to apply the specific properties of this kind of neutron beam to the study of condensed matter. New detection strategies like Filter Difference method and Foil Cycling Technique were also developed in parallel to the detector improvement at the VESUVIO beamline. Recently, epithermal neutron beams were also used at the INES beamline to study elemental and isotopic composition of materials, with special application to cultural heritage studies. In this paper we review a series of epithermal neutron instrumentation developed at ISIS, their evolution over time and main results obtained

  13. Utilization of boron irradiation filters in reactor neutron activation via epithermal (n,γ) and fast neutron reactions

    International Nuclear Information System (INIS)

    Chisela, F.

    1986-01-01

    The technique of instrumental neutron activation analysis based on irradiation with reactor epithermal and fast neutrons has been described and evaluated. Important characteristics of boron neutron absorbers used to remove thermal neutrons from the reactor neutron spectrum have been examined and compared with those of cadmium. Three boron compound shields, have been designed and constructed at the BER II 5MW reactor for use in epithermal neutron activation analysis of biological materials. The major advantages offered by these filters in this application include the flexibility of varying the filter thickness, the low radioactivity induced in the filters during irradiation, ease of fabrication and the relatively low cost of the filter materials. The radiation heating due to the 10 B(n,α) 7 Li-reaction has been experimentally investigated for the filters used and the results obtained confirm the necessity for efficient cooling of these filters during irradiation. Three irradiation facilities have been characterized with respect to the neutron flux density and the flux spatial distribution. An experiment has been designed and carried out to compensate the flux inhomogeneity in two irradiation positions of the DBV facility caused by the reactor geometry. Several biological samples including well characterized reference materials have been analysed after epithermal activation and the results compared with those obtained with the classical thermal neutron activation method. Improved sensitivity of determination has been found for elements with high resonance integral to thermal neutron cross section ratios (RI/σ 0 ). The range of elements that can be determined instrumentally is extended and the time scale of analysis is considerably reduced. (orig.) [de

  14. Epithermal neutron beam interference with cardiac pacemakers

    International Nuclear Information System (INIS)

    Koivunoro, H.; Serén, T.; Hyvönen, H.; Kotiluoto, P.; Iivonen, P.; Auterinen, I.; Seppälä, T.; Kankaanranta, L.; Pakarinen, S.; Tenhunen, M.; Savolainen, S.

    2011-01-01

    In this paper, a phantom study was performed to evaluate the effect of an epithermal neutron beam irradiation on the cardiac pacemaker function. Severe malfunction occurred in the pacemakers after substantially lower dose from epithermal neutron irradiation than reported in the fast neutron or photon beams at the same dose rate level. In addition the pacemakers got activated, resulting in nuclides with half-lives from 25 min to 115 d. We suggest that BNCT should be administrated only after removal of the pacemaker from the vicinity of the tumor.

  15. Epithermal neutron beam interference with cardiac pacemakers

    Energy Technology Data Exchange (ETDEWEB)

    Koivunoro, H., E-mail: hanna.koivunoro@helsinki.fi [Department of Physics, P.O.B. 64, FI-00014 University of Helsinki (Finland)] [Department of Oncology, Helsinki University Central Hospital, P.O.B. 180, FIN-00029 HUS (Finland)] [Boneca Corporation, Finland, Filnland (Finland); Seren, T. [VTT Technical Research Centre of Finland (Finland); Hyvoenen, H. [Boneca Corporation, Finland, Filnland (Finland); Kotiluoto, P. [VTT Technical Research Centre of Finland (Finland); Iivonen, P. [St. Jude Medical (Finland); Auterinen, I. [VTT Technical Research Centre of Finland (Finland); Seppaelae, T.; Kankaanranta, L. [Department of Oncology, Helsinki University Central Hospital, P.O.B. 180, FIN-00029 HUS (Finland); Pakarinen, S. [Department of Cardiology, Helsinki University Central Hospital (Finland); Tenhunen, M. [Department of Oncology, Helsinki University Central Hospital, P.O.B. 180, FIN-00029 HUS (Finland); Savolainen, S. [HUS Helsinki Medical Imaging Center, Helsinki University Central Hospital (Finland)

    2011-12-15

    In this paper, a phantom study was performed to evaluate the effect of an epithermal neutron beam irradiation on the cardiac pacemaker function. Severe malfunction occurred in the pacemakers after substantially lower dose from epithermal neutron irradiation than reported in the fast neutron or photon beams at the same dose rate level. In addition the pacemakers got activated, resulting in nuclides with half-lives from 25 min to 115 d. We suggest that BNCT should be administrated only after removal of the pacemaker from the vicinity of the tumor.

  16. Bromine and iodine in Chinese medical herbs determined via epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Chien-Yi Chen; Yuan-Yaw Wei; Sheng-Pin ChangLai; Lung-Kwang Pan

    2003-01-01

    Nineteen natural herbs and two prescriptions prepared from mixed herbs were analyzed via epithermal neutron activation analysis (ENAA) to evaluate their bromine and iodine concentration. Traditional medical doctors prescribed the samples presented in this work to most Taiwanese children for strengthening their immune systems. Empirical results indicated a wide diversity of bromine in the samples. Yet, the iodine concentration was only around one to tenth or twentieth of the bromine. The maximum daily intake (MDI) for various medical herbs was also widely diversified from one to tenfold on the basis of various criteria. The minimum detectable concentration (MDC) of bromine and iodine found was 0.42±0.14 ppm and 0.067±0.016 ppm, respectively. Compared to that from conventional thermal neutron activation analysis (NAA) for a similar evaluation, the extremely low MDC obtained here was attributed to the large amount of thermal neutron absorption during sample irradiation. (author)

  17. Determination of selenium in Ni + Co concentrates applying epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Capote Rodriguez, G.; Perez Sayaz, G.; Hernandez Rivero, A.; Moreno Bermudez, J.; Ribeiro Guevara, S.; Arribere, M.A.; Molina Insfran, J.

    1996-01-01

    Concentration of Se in Ni + Co concentrates obtained in nickel industry has to be determined as that is a quality control requirement for its commercialization. At present, analysis of Se, specially at a minor and trace levels is relatively complicated and destructive procedures are frequently required. In this work determination of Se by epithermal neutron activation analysis (ENAA) in 17 samples of nickel industry was investigated. Application of ENAA allowed nondestructive determination of Se concentration down to ppm level in spite of presence of high Co, Fe, Ni, and Cr contents in the samples

  18. Comparison of different methods for activation analysis of geological and pedological samples: Reactor and epithermal neutron activation, relative and monostandard method

    International Nuclear Information System (INIS)

    Alian, A.; Sansoni, B.

    1980-04-01

    Using purely instrumental methods, a comparative study is presented on neutron activation analysis of rock and soil samples by whole reactor neutron spectrum and epithermal neutrons with both relative and monostandard procedures. The latter procedure used with epithermal neutron activation analysis of soil samples necessitated the use of the 'effective resonance integrals' which were determined experimentally. The incorporation of the #betta# factor, representing deviation of reactor epithermal neutron flux from 1/E law, is developed in the present work. The main criteria for the choice of one or more of the procedures studied for a given purpose are also indicated. Analysis of 15 trace elements, Ca and Fe in the standard Japanese granite JG-1 using monostandard epithermal neutron activation gave results in good agreement with the average literature values. (orig./RB) [de

  19. Determination of trace cadmium and other elements in bone by epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Dowlati, R.; Jervis, R.E.

    1991-01-01

    Epithermal neutron activation analysis (ENAA) was applied to measure quantitatively Cd and other elements in bone samples from control and Cd-fed rats. This method was found to be non-destructive to the bone samples, with no sign of 'radiolytic charring' and was sensitive enough to detect and quantify Cd in bone samples at normal levels for mammals (viz. 0.5-1.0μg/g) and higher. Two different thermal neutron shield materials were utilized, namely cadmium and boron. The boron shield resulted in a 27% improvement in the detection limit of Cd in bone. The accuracy of ENAA for Cd was assessed by intercomparison with electrothermal atomic absorption spectrophotometry (ETAAS), and the results were in fair agreement (±23%) with those from ENAA. (author) 24 refs.; 5 tabs

  20. Measurement of trace cadmium and elements in bone by epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Dowlati, R.; Jervis, R.E.

    1991-01-01

    Epithermal neutron activation analysis (ENAA) was applied to measure quantitatively Cd and other elements in bone samples from control and Cd-fed rats. This method was found to be non-destructive to the bone samples, with no sign of 'radiolytic charring' and was sensitive enough to detect and quantify Cd in bone samples at normal levels for mammals (viz. 0.5-1.0 μg/g) and higher. Two different thermal neutron shield materials were utilized, namely cadmium and boron. The boron shield resulted in a 27% improvement in the detection limit of Cd in bone. The accuracy of ENAA for Cd was assessed by intercomparison with electrothermal atomic absorption spectrophotometry (ETAAS), and the results in fair agreement (±23%) with those from ENAA

  1. Temperature imaging using epithermal neutrons

    International Nuclear Information System (INIS)

    Fowler, P.H.; Taylor, A.D.

    1987-08-01

    The paper concerns the temperature measurement of suitable targets, both remotely and non-invasively, using epithermal neutrons. The text was presented at the Neutron Resonance Radiography Workshop, Los Alamos, U.S.A., 1987. The technique is demonstrated for tantalum foils at different temperatures, using a pulsed beam of epithermal neutrons, at both Los Alamos and ISIS (United Kingdom). Results on the measured time-of-flight spectra and the tantalum resonances are presented. Beam properties and fluxes at ISIS are discussed. Features of the proposed detectors suitable for the temperature technique are outlined, along with the data analysis, the moving targets, the cyclic temperature variations and transients, and the usefulness of the technique. (U.K.)

  2. Study on the determination of uranium by activation analysis with epithermal neutrons

    International Nuclear Information System (INIS)

    Atalla, L.T.

    1977-01-01

    A method is described that is applied to the determination of uranium in different types of materials, either by an entirely instrumental method or with the chemical separation of uranium-239, when the presence of interferences does not allow the instrumental analysis. The advantages and disadvantages in the use of epithermal neutrons in the activation of samples for a more selective activation of uranium-238 also presented. The instrumental method is tested through standart materials, accepted internationally. The possibility of uranium extraction with di-etil-hexilphosphoric acid is also presented and the choice of the former technique is justified. The sensitibility of the method is discussed as well as precision and accuracy through results obtained in the analysis of the standards and the calibration curve of uranium [pt

  3. Investigations on the comparator technique used in epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Bereznai, T.; Bodizs, D.; Keoemley, G.

    1977-01-01

    The possible extension of the comparator technique of reactor neutron activation analysis into the field of epithermal neutron activation has been investigated. Ruthenium was used for multi-isotopic comparator. Experiments show that conversion of the so-called reference k-factors - determined by irradiation with reactor neutrons - into ksup(epi)-factors usable at activation under cadmium filter, can be evaluated with fair accuracy. Sources and extent of errors and their contribution to the final error of analysis are discussed. For equal irradiation and counting times advantage of ENAA for several elements is obvious: the much lower background activity permitted the sample to be measured closer to the detector, under better geometry conditions, consequently, permitting several elements to be determined quantitatively. The number of elements determined and the sensitivity of the method are much dependent on the experimental conditions, especially on the composition of the sample, on the PHIsub(e) value, the irradiation time and the efficiency of the Ge(Li) detector. (T.G.)

  4. Distribution of 35 Elements in Peat Cores from Ombrotrophic Bogs Studied by Epithermal Neutron Activation Analysis

    CERN Document Server

    Frontasyeva, M V

    2004-01-01

    In ombrotrophic bogs the surface peat layer is supplied with chemical substances only from the atmosphere. Peat cores from these bogs therefore can be used to study temporal trends in atmospheric deposition of pollutants. In this work epithermal neutron activation analysis was applied for the first time to study the distribution of 35 elements in peat profiles from ombrotrophic bogs. The selected examples were from Finnmark county in northern Norway: one pristine site far from any local pollution source, and another strongly affected by long-term operation of Russian copper-nickel smelters located close to the border. The elements are classified with respect to their behavior in the uppermost 40 cm of the peat, and similarities and differences between the two profiles are discussed. As compared with other more commonly used analytical techniques based on acid decomposition of the sample ENAA has the advantage of providing the total concentrations of the elements.

  5. Study on iodine levels in thyroids of iodine-supplemented rats by epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Wang Xuefei; Zhang Fang; Xu Qing; Liu Nianqing; Chai Zhifang; Zhao Xueqin; Zuo Aijun

    2003-01-01

    The second generation female Wistar rats that have been treated with iodine-deficient food, after their delivery, are divided into three groups i.e. excessive-iodine (EI), adequate-iodine (AI) and iodine-deficient (ID) according to the KIO 3 concentration in the drinking water (3.0, 0.4, 0 mg/L). In addition, the normal rats with low iodine food and 0.4 mg/L KIO 3 water are used as the control group (C). The iodine content in thyroid and the serum thyroid hormone levels of the third generation rats are measured by means of epithermal neutron activation analysis (ENAA), and the method of enzyme-linked immunosorbent assay (ELISA), respectively. The results indicate that the total thyroxine (TT 4 ) and the free thyroxine (FT 4 ) of the EI, compared with those of the controls, are significantly decreased (p 3 ) evidently increased (p 4 , FT 4 and goiter

  6. Elimination of eight interfering radioisotopes in the determination of uranium by activation analysis with epithermic neutrons

    International Nuclear Information System (INIS)

    Requejo, C.S.

    1977-01-01

    The total or parcial elimination interfering radioisotopes in activation analysis of uranium by epithermic neutrons, has been made. It was possible to determine uranium, after chemical separation, from samples of organic and mineral matrixes, which had mercury, selenium, bromine, antimony, gold, barium, molybden and tungsten. Mineral samples were analysed giving results between 0.2 to 5.0 ppm of uranium. The same mineral were ground in agate mortar and in tungsten carbide mill. In the first sample is has been found 0.2277 +- -+ 0.0474 ppm U. The second which had tungsten, at level of 150 ppm, after radiochemical separation, it has been found 0.2465+- -+0.0326 ppm U. These results are considered statistically the same [pt

  7. Measurement of thermal, epithermal and fast neutron flux in the IEA-R1 reactor by the foil activation method

    International Nuclear Information System (INIS)

    Koskinas, M.F.

    1979-01-01

    Experimental and theoretical details of the foil activation method applied to neutrons flux measurements at the IEA-R1 reactor are presented. The thermal - and epithermal - neutron flux were determined form activation measurements of gold, cobalt and manganese foils; and for the fast neutron flux determination, aluminum, iron and nickel foils were used. The measurements of the activity induced in the metal foils were performed using a Ge-Li gamma spectrometry system. In each energy range of the reactor neutron spectrum, the agreement among the experimental flux values obtained using the three kind of materials, indicates the consistency of the theoretical approach and of the nuclear parameters selected. (Author) [pt

  8. Errors of absolute methods of reactor neutron activation analysis caused by non-1/E epithermal neutron spectra

    International Nuclear Information System (INIS)

    Erdtmann, G.

    1993-08-01

    A sufficiently accurate characterization of the neutron flux and spectrum, i.e. the determination of the thermal flux, the flux ratio and the epithermal flux spectrum shape factor, α, is a prerequisite for all types of absolute and monostandard methods of reactor neutron activation analysis. A convenient method for these measurements is the bare triple monitor method. However, the results of this method, are very imprecise, because there are high error propagation factors form the counting errors of the monitor activities. Procedures are described to calculate the errors of the flux parameters, the α-dependent cross-section ratios, and of the analytical results from the errors of the activities of the monitor isotopes. They are included in FORTRAN programs which also allow a graphical representation of the results. A great number of examples were calculated for ten different irradiation facilities in four reactors and for 28 elements. Plots of the results are presented and discussed. (orig./HP) [de

  9. Pulsed neutron sources for epithermal neutrons

    International Nuclear Information System (INIS)

    Windsor, C.G.

    1978-01-01

    It is shown how accelerator based neutron sources, giving a fast neutron pulse of short duration compared to the neutron moderation time, promise to open up a new field of epithermal neutron scattering. The three principal methods of fast neutron production: electrons, protons and fission boosters will be compared. Pulsed reactors are less suitable for epithermal neutrons and will only be briefly mentioned. The design principle of the target producing fast neutrons, the moderator and reflector to slow them down to epithermal energies, and the cell with its beam tubes and shielding will all be described with examples taken from the new Harwell electron linac to be commissioned in 1978. A general comparison of pulsed neutron performance with reactors is fraught with difficulties but has been attempted. Calculation of the new pulsed source fluxes and pulse widths is now being performed but we have taken the practical course of basing all comparisons on extrapolations from measurements on the old 1958 Harwell electron linac. Comparisons for time-of-flight and crystal monochromator experiments show reactors to be at their best at long wavelengths, at coarse resolution, and for experiments needing a specific incident wavelength. Even existing pulsed sources are shown to compete with the high flux reactors in experiments where the hot neutron flux and the time-of-flight methods can be best exploited. The sources under construction can open a new field of inelastic neutron scattering based on energy transfer up to an electron volt and beyond

  10. Determination of 30 elements in coal and fly ash by thermal and epithermal neutron-activation analysis

    International Nuclear Information System (INIS)

    Rowe, J.J.; Steinnes, E.

    1977-01-01

    Thirty elements are determined in coal and fly ash by instrumental neutron-activation analysis using both thermal and epithermal irradiation. Gamma-ray spectra were recorded 7 and 20 days after the irradiations. The procedure is applicable to the routine analysis of coals and fly ash. Epithermal irradiation was found preferable for the determination of Ni, Zn, As, Se, Br, Rb, Sr, Mo, Sb, Cs, Ba, Sm, Tb, Hf, Ta, W, Th and U, whereas thermal irradiation was best for Sc, Cr, Fe, Co, La, Ce, Nd, Eu, Yb and Lu. Results for SRM 1632 (coal) and SRM 1633 (fly ash) agree with those of other investigators. (author)

  11. Polarized epithermal neutron spectrometer at KENS

    International Nuclear Information System (INIS)

    Kohgi, M.

    1983-01-01

    A spectrometer employing a white, epithermal, polarized neutron beam is under construction at KENS. The neutron polarization is achieved by passage through a dynamically polarized proton filter (DPPF). The results of the test experiments show that the DPPF method is promising in obtaining polarized epithermal neutron beam. The basic design of the spectrometer is described

  12. Determination of Uranium and Thorium in Brazilian coals by epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Bernedo, L.F.B.

    1981-08-01

    An experimental technique for the determination of uranium and thorium in coal by epithermal neutron activation was developed and systemized. Seventeen different coal samples, six copper monitors for neutron flux corrections and three NBS standard coal samples were irradiated together in a cadmium cylinder. Uranium and thorium were determined by measuring the 239 N sub(p) and 233 P sub(a) activities respectively, being both produced in (n,γ) reactions and subsequent β - decay. The 239 N sub(p) was measured by counting the 106.4 KeV γ-ray in a LEPS detector and the 233 P sub(a) by counting the 311.8 KeV γ-ray, but in a Ge(Li) detector. A 4096 multichannel analizer and a PDP-11 computer complemented the basic measuring equipment. An average precision of 3% was obtained in the analysis of seventeen coal samples coming from different strata and heights of Charqueadas and Morungava mines in Rio Grande do Sul State. The sensitivity of the method is around 100 ppb. This technique will allow determinations of up to twenty elements, besides uranium and thorium, and it can be applied in routine analysis. (Author) [pt

  13. Determination of uranium in tree bark samples by epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Lima, Nicole Pereira de; Saiki, Mitiko

    2017-01-01

    In this study uranium (U) concentrations were determined in certified reference materials (CRMs) and in tree bark samples collected in 'Cidade Universitaria Armando de Salles Oliveira' (CUASO) USP, Sao Paulo, SP, Brazil). The barks were collected from different species namely Poincianella pluviosa and Tipuana tipu. These bark samples were cleaned, dried, grated and milled for the analyses by epithermal neutron activation analysis method (ENAA). This method consists on irradiating samples and U standard in IEAR1 nuclear reactor with thermal neutron flux of 1:9 x 10 12 n cm -2 s -1 during 40 to 60 seconds depending on the samples matrices. The samples and standard were measured by gamma ray spectroscopy. U was identified by the peak of 74.66 keV of 239 U with half life of 23.47 minutes. Concentration of U was calculated by comparative method. For analytical quality control of U results, certified reference materials were analysed. Results obtained for CRMs presented good precision and accuracy, with |Z score| <= 0.39. Uranium concentrations in tree barks varied from 83.1 to 627.6 ng g - 1 and the relative standard deviations of these results ranged from 1.8 to 10%. (author)

  14. Determination of uranium in tree bark samples by epithermal neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Nicole Pereira de; Saiki, Mitiko, E-mail: mitiko@ipen.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    In this study uranium (U) concentrations were determined in certified reference materials (CRMs) and in tree bark samples collected in 'Cidade Universitaria Armando de Salles Oliveira' (CUASO) USP, Sao Paulo, SP, Brazil). The barks were collected from different species namely Poincianella pluviosa and Tipuana tipu. These bark samples were cleaned, dried, grated and milled for the analyses by epithermal neutron activation analysis method (ENAA). This method consists on irradiating samples and U standard in IEAR1 nuclear reactor with thermal neutron flux of 1:9 x 10{sup 12} n cm{sup -2} s{sup -1} during 40 to 60 seconds depending on the samples matrices. The samples and standard were measured by gamma ray spectroscopy. U was identified by the peak of 74.66 keV of {sup 239}U with half life of 23.47 minutes. Concentration of U was calculated by comparative method. For analytical quality control of U results, certified reference materials were analysed. Results obtained for CRMs presented good precision and accuracy, with |Z score| <= 0.39. Uranium concentrations in tree barks varied from 83.1 to 627.6 ng g{sup -} {sup 1} and the relative standard deviations of these results ranged from 1.8 to 10%. (author)

  15. Epithermal neutron activation analysis of CR(VI)-reducer basalt-inhabiting bacteria

    International Nuclear Information System (INIS)

    Tsibakhashvili, N.Ya.; Kalabegishvili, T.L.; Murusidze, I.G.; Mosulishvili, L.M.; Frontas'eva, M.V.; Kirkesali, E.I.; Aksenova, N.G.; Holman, H.Y.

    2005-01-01

    Epithermal neutron activation analysis (ENAA) has been applied to studying elemental composition of Cr(VI)-reducer bacteria isolated from polluted basalts from the Republic of Georgia. Cr(VI)-reducing ability of the bacteria was examined by electron spin resonance (ESR) demonstrating that the bacteria differ in the rates of Cr(VI) reduction. A well-pronounced correlation between the ability of the bacteria to accumulate Cr(VI) and their ability to reduce Cr(V) to Cr(III) observed in our experiments is discussed. Elemental analysis of these bacteria also revealed that basalt-inhabiting bacteria are distinguished by relative contents of essential elements such as K, Na, Mg, Fe, Mn, Zn, and Co. A high rate of Cr(III) formation correlates with a high concentration of Co in the bacterium. ENAA detected some similarity in the elemental composition of the bacteria. The relatively high contents of Fe detected in the bacteria (140-340 μg/g of dry weight) indicate bacterial adaptation to the environmental conditions typical of the basalts. The concentrations of at least 12-19 different elements ranging from major- to ultratrace ones were determined in each type of bacteria simultaneously. The range of concentrations spans over 8 orders of magnitude

  16. Marine Gradients of Halogens in Moss Studied by Epithermal Neutron Activation Analysis

    CERN Document Server

    Frontasyeva, M V

    2002-01-01

    Epithermal neutron activation analysis is known to be a powerful technique for the simultaneous study of chlorine, bromine and iodine in environmental samples. In this paper it is shown to be useful to elucidate marine gradients of these elements. Examples are from a transect study in northern Norway where samples of the feather moss Hylocomium splendens were collected at distances 0-300 km from the coastline. All three elements decreased exponentially as a function of distance from the ocean in the moss samples, strongly indicating that atmospheric supply from the marine environment is the predominant source of these elements to the terrestrial ecosystem. These results are compared with similar data for surface soils along the same gradients. Comparison is also made with previous data for halogens in moss in Norway obtained by conventional NAA and covering similar transects in other geographical regions. The Cl/Br and Br/I ratios in moss showed a regular change distance from the ocean in all transects, and h...

  17. Epithermal Neutron Activation Analysis (ENAA) of Cr(VI)-reducer Basalt-inhabiting Bacteria

    CERN Document Server

    Tsibakhashvili, N Ya; Kirkesali, E I; Aksenova, N G; Kalabegishvili, T L; Murusidze, I G; Mosulishvili, L M; Holman, H Y N

    2005-01-01

    Epithermal neutron activation analysis (ENAA) has been applied to studying elemental composition of Cr(VI)-reducer bacteria isolated from polluted basalts from the Republic of Georgia. Cr(VI)-reducing ability of the bacteria was examined by electron spin resonance (ESR) demonstrating that the bacteria differ in the rates of Cr(VI) reduction. A well-pronounced correlation between the ability of the bacteria to accumulate Cr(V) and their ability to reduce Cr(V) to Cr(III) observed in our experiments is discussed. Elemental analysis of these bacteria also revealed that basalt-inhabiting bacteria are distinguished by relative contents of essential elements such as K, Na, Mg, Fe, Mn, Zn, and Co. A high rate of Cr(III) formation correlates with a high concentration of Co in the bacterium. ENAA detected some similarity in the elemental composition of the bacteria. The relatively high contents of Fe detected in the bacteria (140-340 $\\mu $g/g of dry weight) indicate bacterial adaptation to the environmental condition...

  18. Mechanical design of epithermal neutron diagnostic for TFTR

    International Nuclear Information System (INIS)

    Groo, R.C.

    1981-01-01

    The mechanical design of the Epithermal Neutron Diagnostic for TFTR is described. This fission detector system measures the time resolution of the neutron flux for folding into the Neutron Activation system and also provides continuous, wide range coverage of all expected fusion reaction rates

  19. Epithermal neutron activation analysis of Spirulina platensis biomass, of the C-phycocianin and of DNA extracted from it

    International Nuclear Information System (INIS)

    Mosulishvili, L.M.; Belokobyl'skij, A.I.; Kirkesali, E.I.; Khizanishvili, A.I.; Frontas'eva, M.V.; Pomyakushina, E.V.

    2002-01-01

    The epithermal neutron activation analysis (ENAA) was used for study of the biomass of Spirulina platensis. The background levels of concentration of 27 macro-, micro- and trace elements ranging from 10 -3 up to 10 4 ppm were determined. It was found that the biomass of Spirulina does not contain toxic elements above the tolerance levels and can be utilized as a matrix of pharmaceuticals based on it. The concentrations of basic elements in C-phycocianin and DNA extracted from Spirulina platensis were determined by ENAA. A comparison of the element content of a whole Spirulina biomass with that of a refined C-phycocianin preparation was made

  20. Application of Epithermal Neutron Activation Analysis to Investigate Accumulation and Adsorption of Mercury by Spirulina platensis Biomass

    CERN Document Server

    Mosulishvili, L M; Khizanishvili, A I; Frontasyeva, M V; Kirkesali, E I; Aksenova, N G

    2004-01-01

    Epithermal neutron activation analysis was used to study interaction of blue-green alga Spirulina platensis with toxic metal mercury. Various concentrations of Hg(II) were added to cell cultures in a nutrient medium. The dynamics of accumulation of Hg was investigated over several days in relation to Spirulina biomass growth. The process of Hg adsorption by Spirulina biomass was studied in short-time experiments. The isotherm of adsorption was carried out in Freindlich coordinates. Natural Spirulina biomass has potential to be used in the remediation of sewage waters at Hg concentrations \\sim 100 {\\mu}g/l.

  1. Application of epithermal neutron activation analysis to investigate accumulation and adsorption of mercury by Spirulina platensis biomass

    International Nuclear Information System (INIS)

    Mosulishvili, L.M.; Belokobyl'skij, A.I.; Khizanishvili, A.I.; Frontas'eva, M.V.; Kirkesali, E.I.; Aksenova, N.G.

    2004-01-01

    Epithermal neutron activation analysis was used to study interaction of blue-green alga Spirulina platensis with toxic metal mercury. Various concentrations of Hg(II) were added to cell cultures in a nutrient medium. The dynamics of accumulation of Hg was investigated over several days in relation to Spirulina biomass growth. The process of Hg adsorption by Spirulina biomass was studied in short-time experiments. The isotherm of adsorption was carried out in Freindlich coordinates. Natural Spirulina biomass has potential to be used in the remediation of sewage waters at Hg concentrations ∼100 μg/1

  2. Epithermal Neutron Activation Analysis of Spirulina platensis Biomass, of the C-Phycocianin and of DNA Extracted from It

    CERN Document Server

    Mosulishvili, L M; Belokobylsky, A I; Kirkesali, E I; Khizanishvili, A I; Pomyakushina, E V

    2002-01-01

    The epithermal neutron activation analysis (ENAA) was used for study of the biomass of Spirulina platensis. The background levels of concentration 27 macro-, micro- and trace elements ranging from 10^{-3} up to 10^{4} ppm were determined. It was found that the biomass of spirulina does not contain toxic elements above the tolerance levels and can be utilized as a matrix of pharmaceuticals based on it. The concentrations of basic elements in C-phycocianin and DNA extracted from Spirulina platensis were determined by ENAA. A comparison of the element content of a whole spirulina biomass with that of a refined C-phycocianin preparation was made.

  3. Epithermal neutron flux distribution and its impact on (n, γ) activation analysis result

    International Nuclear Information System (INIS)

    Jovanovich, S.; Pukotich, P.; Zejnilovich, R.; Corte, F. de; Moens, L.; Hoste, J.; Simonitis, A.

    1985-01-01

    The differences are discussed between the simplified model, introduced to derive the generally accepted ideal 1/E - law, and the conditions existing in an actual reactor. For absolute and comparator types of (n, γ) activation analysis (NAA), the semiempirical 1/Esup(1+α) form is a better approximation - necessary to introduce, but sufficient for practical purposes. Parameter α, being a measure of the epithermal nonideality, is a characteristics of the reactor site. The impact of this nonideality on NAA result is outlined, together with the method for appropriate correction

  4. Polarized Epithermal Neutron Studies of Magnetic Domains

    International Nuclear Information System (INIS)

    Alfimenkov, V.P.; Chernikov, A.N.; Lason, L.; Mareev, Yu. D.; Novitsky, V.V.; Pikelner, L.B.; Skoy, V.R.; Tsulaya, M.I.; Gould, C.R.; Haase, D.G.; Roberson, N.R.

    1997-01-01

    The average size and shape of magnetic domains in a material can be determined from the precession of polarized neutrons traversing the material. Epithermal neutrons (0.5eV< En<100eV), which process more slowly than thermals, effectively probe the internal structure of samples that are thick or have large domains or large internal fields. Such epithermal neutron measurements require a neutron polarizer and analyzer based on cryogenically polarized spin filters. We discuss the measurements at JINR, Dubna, of magnetic domains in a 2.0 cm. diam. crystal of holmium using 1.7 to 59eV neutrons polarized by a dynamically polarized proton target and analyzed with a statically polarized dysprosium target

  5. Polarized epithermal neutron studies of magnetic domains

    International Nuclear Information System (INIS)

    Alfimenkov, V.P.; Chernikov, A.N.; Lason, L.; Mareev, Y.D.; Novitsky, V.V.; Pikelner, L.B.; Skoy, V.R.; Tsulaya, M.I.; Gould, C.R.; Haase, D.G.; the Triangle Universities Nuclear Laboratory, Durham, North Carolina; Roberson, N.R.; the Triangle Universities Nuclear Laboratory, Durham, North Carolina

    1997-01-01

    The average size and shape of magnetic domains in a material can be determined from the precession of polarized neutrons traversing the material. Epithermal neutrons (0.5eV n <100eV), which precess more slowly than thermals, effectively probe the internal structure of samples that are thick or have large domains or large internal fields. Such epithermal neutron measurements require a neutron polarizer and analyzer based on cryogenically polarized spin filters. We discuss the measurement at JINR, Dubna, of magnetic domains in a 2.0 cm. diam. crystal of holmium using 1.7 to 59 eV neutrons polarized by a dynamically polarized proton target and analyzed with a statically polarized dysprosium target. copyright 1997 American Institute of Physics

  6. Epithermal neutron activation analysis of blue-green algae Spirulina Platensis as a matrix for selenium-containing pharmaceuticals

    International Nuclear Information System (INIS)

    Mosulishvili, L.M.; Kirkesali, E.I.; Belokobyl'skij, A.I.; Khizanishvili, A.I.; Frontas'eva, M.V.; Gundorina, S.F.; Oprea, C.D.

    2000-01-01

    To evaluate the potentiality of the blue-green algae Spirulina Platensis as a matrix for the production of Se-containing pharmaceuticals, the background levels of 31 major, minor and trace elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni (using (n,p)-reaction), As, Br, Zn, Rb, Mo, Ag, Sb, I, Ba, Sm, Tb, Tm, Hf, Ta, W, Au, Hg, Th) in Spirulina Platensis biomass were determined by means of epithermal neutron activation analysis. The possibility of the purpose-oriented incorporation of Se into Spirulina Platensis biomass was demonstrated. The polynomial dependence of the Se accumulation on nutritional medium loading was revealed. The employed analytical technique allows one to reliably control the amount of toxic elements in algae Spirulina Platensis. Based on this study, a conclusion of the possibility to use Spirulina Platensis as a matrix for the production of Se-containing pharmaceuticals was drawn

  7. Boron thermal/epithermal neutron capture therapy

    International Nuclear Information System (INIS)

    Fairchild, R.G.

    1982-01-01

    The development of various particle beams for radiotherapy represents an attempt to improve dose distribution, and to provide high LET radiations which are less sensitive to ambient physical and radiobiological factors such as oxygen tension, cell cycle, and dose rate. In general, a compromise is necessary as effective RBE is reduced in order to spread the dose distribution over the anticipated tumor volume. The approach of delivering stable non-toxic isotopes to tumor, and then activating these atoms subsequently via an external radiation beam has mator advantages; problems associated with high uptake of these isotopes in competing cell pools are obviated, and the general tumor volume can be included in the treatment field of the activating beam. As long as the normal tissues supporting tumor show a low uptake of the isotope to be activated, and as long as the range of the reaction products is short, dose will be restricted to tumor, with a consequent high therapeutic ratio. Neutron Capture Therapy (NCT) is generally carried out by activating boron-10 with low energy neutrons. The range of the high LET, low OER particles from the 10 B(n, α) 7 Li reaction is approx. 10μ, or one cell diameter, a situation that is optimal for cell killing. Significant advantages may be gained by using the NCT procedure in conjunction with improved tissue penetration provided with epithermal or filtered beams, and new compounds showing physiological binding to tumor

  8. Fast and epithermal neutron radiography using neutron irradiator

    International Nuclear Information System (INIS)

    Oliveira, Karol A.M. de; Crispim, Verginia R.; Ferreira, Francisco J.O.

    2013-01-01

    The neutron radiography technique (NR) with neutrons in the energy range fast to epithermal is a powerful tool used in no-destructive inspection of bulky objects of diverse materials, including those rich in hydrogen, oxygen, nitrogen ad carbon. Thus, it can be used to identify, inclusions, voids and thickness differences in materials such as explosive artifacts and narcotics. Aiming at using NR with fast and epithermal neutrons, an Irradiator was constructed by: a 241 Am-Be source, with 5 Ci activity, a collimator with adjustable collimation rate, L/D; and a shield device composed by plates of borated paraffin and iron. The test specimens chosen were a Beam Purity Indicator (BPI) and an Indicator of Visual Resolution (IVR). The neutron radiography images obtained had a resolution of 444.4 μm and 363.6 μm respectively when registered in: 1) the sheet of the nuclear track solid detector, CR-39 type, through X (n,p) Y nuclear reaction; and 2) Kodak Industrex M radiographic film plate in close contact with a boron converter screen, both stored in a Kodak radiographic cassette. (author)

  9. Use of boron nitride for neutron spectrum characterization and cross-section validation in the epithermal range through integral activation measurements

    Science.gov (United States)

    Radulović, Vladimir; Trkov, Andrej; Jaćimović, Radojko; Gregoire, Gilles; Destouches, Christophe

    2016-12-01

    A recent experimental irradiation and measurement campaign using containers made from boron nitride (BN) at the Jožef Stefan Institute (JSI) TRIGA Mark II reactor in Ljubljana, Slovenia, has shown the applicability of BN for neutron spectrum characterization and cross-section validation in the epithermal range through integral activation measurements. The first part of the paper focuses on the determination of the transmission function of a BN container through Monte Carlo calculations and experimental measurements. The second part presents the process of tayloring the sensitivity of integral activation measurements to specific needs and a selection of suitable radiative capture reactions for neutron spectrum characterization in the epithermal range. A BN container used in our experiments and its qualitative effect on the neutron spectrum in the irradiation position employed is displayed in the Graphical abstract.

  10. Determination of the thermal and epithermal neutron sensitivities of an LBO chamber

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Satoru; Kotani, Kei; Kajimoto, Tsuyoshi; Tanaka, Kenichi [Hiroshima University, Quantum Energy Applications, Graduate School of Engineering, Higashi-Hiroshima (Japan); Sato, Hitoshi; Nakajima, Erika [Ibaraki Prefectural University of Health Science, Radiological Sciences, Ibaraki (Japan); Shimazaki, Takuto [Hiroshima University, Quantum Energy Applications, Graduate School of Engineering, Higashi-Hiroshima (Japan); Delta Kogyo Co., Ltd., Hiroshima (Japan); Suda, Mitsuru; Hamano, Tsuyoshi [National Institute of Radiological Sciences, Chiba-Shi, Chiba (Japan); Hoshi, Masaharu [Hiroshima University, Institute for Peace Science, Hiroshima (Japan)

    2017-08-15

    An LBO (Li{sub 2}B{sub 4}O{sub 7}) walled ionization chamber was designed to monitor the epithermal neutron fluence in boron neutron capture therapy clinical irradiation. The thermal and epithermal neutron sensitivities of the device were evaluated using accelerator neutrons from the {sup 9}Be(d, n) reaction at a deuteron energy of 4 MeV (4 MeV d-Be neutrons). The response of the chamber in terms of the electric charge induced in the LBO chamber was compared with the thermal and epithermal neutron fluences measured using the gold-foil activation method. The thermal and epithermal neutron sensitivities obtained were expressed in units of pC cm{sup 2}, i.e., from the chamber response divided by neutron fluence (cm{sup -2}). The measured LBO chamber sensitivities were 2.23 x 10{sup -7} ± 0.34 x 10{sup -7} (pC cm{sup 2}) for thermal neutrons and 2.00 x 10{sup -5} ± 0.12 x 10{sup -5} (pC cm{sup 2}) for epithermal neutrons. This shows that the LBO chamber is sufficiently sensitive to epithermal neutrons to be useful for epithermal neutron monitoring in BNCT irradiation. (orig.)

  11. Examination of Greek neolithic ceramic shards by epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Ochsenkuehn, K.M.; Zouridakis, N.; Inst. of Physical Chemistry, Athens; Ochsenkuehn-Petropulu, M.

    1999-01-01

    At the reactor of the NCSR 'Demokritos' epithermal irradiation was used in connection with a loss-free counting technique to investigate rare Neolithic ceramic shards, about 4000 years old, from the Alepotrypa Cave of Diros, Greece. The application of an irradiation time of 30 minutes, the measurements of the samples after less then 24 hours and a counting time of 20 minutes in connection with a loss-free counting unit allowed the determination of 12 elements per sample. The comparison of these rare fine ceramic shards with those of primitive shape showed that both were produced from the same raw materials. Small differences could be explained by a raw material pretreatment. The Neolithic potters were obviously aware of separation techniques in order to obtain fine clay fractions to produce those rare ceramics. (author)

  12. Epithermal neutron activation analysis of major and trace elements in Red Sea scleractinian corals

    International Nuclear Information System (INIS)

    Abdo, S.Y.; Sherif, M.M.; Frontasyeva, M.V.

    2017-01-01

    Five corals belonging to common scleractinian reef-building species, and collected from Gulf of Suez, Egypt were subjected to neutron activation analysis. The content of 26 elements: Na, Mg, Cl, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Zn, As, Br, Rb, Sr, Sb, I, Cs, Ba, La, Ce, Gd, Hf, Th, and U was experimentally determined. Ca and Sr have the highest content i.e. 38.4-39.5% and 0.73-0.78% respectively while, the content of all other elements was within the ranges reported for the worldwide corals. For a better understanding of the coral exoskeleton elemental content, the partition coefficient calculated for all determined elements showed a wide range of values varying from 2 × 10 -4 in the case of Cl to 2 × 10 3 for Ce and other insoluble elements. Although all corals were collected in the vicinity of the Port Suez no traces of anthropogenic contamination were evidenced. (author)

  13. Characteristic analysis on moderating material for obtaining epithermal neutron beam

    International Nuclear Information System (INIS)

    Jiang Xinbiao; Chen Da; Zhang Ying

    2000-01-01

    The one dimension discrete coordinates transport code ANISN was used to calculate three-group constants of 11 elements which could be used to consist moderating epithermal neutron material of beam. Moderating character of simple substances, compounds and mixtures consisted of the optimized elements analyzed three kinds of moderating materials were optimized for epithermal neutron beam

  14. Application of epithermal neutron activation in multielement analysis of silicate rocks employing both coaxial Ge(Li) and low energy photon detector systems

    Science.gov (United States)

    Baedecker, P.A.; Rowe, J.J.; Steinnes, E.

    1977-01-01

    The instrumental activation analysis of silicate rocks using epithermal neutrons has been studied using both high resolution coaxial Ge(Li) detectors and low energy photon detectors, and applied to the determination of 23 elements in eight new U.S.G.S. standard rocks. The analytical use X-ray peaks associated with electron capture or internal conversion processes has been evaluated. Of 28 elements which can be considered to be determinable by instrumental means, the epithermal activation approach is capable of giving improved sensitivity and precision in 16 cases, over the normal INAA procedure. In eleven cases the use of the low energy photon detector is thought to show advantages over convertional coaxial Ge(Li) spectroscopy. ?? 1977 Akade??miai Kiado??.

  15. The epithermal neutron-flux distribution in the reactor RA - Vinca

    International Nuclear Information System (INIS)

    Marinkov, V.; Bikit, I.; Martinc, R.; Veskovic, M.; Slivka, J.; Vaderna, S.

    1987-01-01

    The distribution of the epithermal neutron flux in the reactor RA - Vinca has been measured by means of Zr - activation detectors. In the channel VK-8 non-homogeneous flux distribution was observed (author) [sr

  16. Use of boron nitride for neutron spectrum characterization and cross-section validation in the epithermal range through integral activation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Radulović, Vladimir, E-mail: vladimir.radulovic@ijs.si [Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Trkov, Andrej [Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); IAEA, Vienna International Centre, PO Box 100, A-1400 Vienna (Austria); Jaćimović, Radojko [Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Gregoire, Gilles; Destouches, Christophe [CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St. Paul-Lez-Durance (France)

    2016-12-21

    A recent experimental irradiation and measurement campaign using containers made from boron nitride (BN) at the Jožef Stefan Institute (JSI) TRIGA Mark II reactor in Ljubljana, Slovenia, has shown the applicability of BN for neutron spectrum characterization and cross-section validation in the epithermal range through integral activation measurements. The first part of the paper focuses on the determination of the transmission function of a BN container through Monte Carlo calculations and experimental measurements. The second part presents the process of tayloring the sensitivity of integral activation measurements to specific needs and a selection of suitable radiative capture reactions for neutron spectrum characterization in the epithermal range. A BN container used in our experiments and its qualitative effect on the neutron spectrum in the irradiation position employed is displayed in the Graphical abstract. - Graphical abstract: Neutron spectra inside the JSI TRIGA Mark II PT irradiation position, obtained with a Monte Carlo calculation: blue: unperturbed, green inside a BN container, of wall thickness 4 mm, 13 mm in diameter and 14 mm in height.

  17. Use of boron nitride for neutron spectrum characterization and cross-section validation in the epithermal range through integral activation measurements

    International Nuclear Information System (INIS)

    Radulović, Vladimir; Trkov, Andrej; Jaćimović, Radojko; Gregoire, Gilles; Destouches, Christophe

    2016-01-01

    A recent experimental irradiation and measurement campaign using containers made from boron nitride (BN) at the Jožef Stefan Institute (JSI) TRIGA Mark II reactor in Ljubljana, Slovenia, has shown the applicability of BN for neutron spectrum characterization and cross-section validation in the epithermal range through integral activation measurements. The first part of the paper focuses on the determination of the transmission function of a BN container through Monte Carlo calculations and experimental measurements. The second part presents the process of tayloring the sensitivity of integral activation measurements to specific needs and a selection of suitable radiative capture reactions for neutron spectrum characterization in the epithermal range. A BN container used in our experiments and its qualitative effect on the neutron spectrum in the irradiation position employed is displayed in the Graphical abstract. - Graphical abstract: Neutron spectra inside the JSI TRIGA Mark II PT irradiation position, obtained with a Monte Carlo calculation: blue: unperturbed, green inside a BN container, of wall thickness 4 mm, 13 mm in diameter and 14 mm in height.

  18. Determination of elemental concentrations in airborne particulate matter in the City of Santiago de Chile, through neutron activation analysis using epithermal neutrons and Compton suppression system

    International Nuclear Information System (INIS)

    Rojas S, Ximena

    1995-01-01

    In order to optimize the Neutron-Activation Analysis (NAA) technique currently carried out in our country, the present work was carried out in the United States where irradiations with epithermal neutrons and a Compton suppression system were used, which allowed the characterization of aerosols of the city of Santiago de Chile. With this purpose, 54 filters of polycarbonate membranes were analysed with aerosols collected in an area of the capital during Spring 1993 and Winter of 1994. As a result, an improvement in the detection limits was observed, specially in elements such as Ni and Zn, which are not easily detectable through NAA. The application of both systems also permits the usage of this technique in geological and biological samples, where the presence of Na, Al and Cl obstruct the determination of some elements. The determined elements in both fractions were Mn, V, Cu, As, Sb, Co, Br, Cl, Ni, Zn, Ca, Al, Na and Fe. (author). 8 refs., 7 figs., 9 tabs

  19. Internal-standard method for the determination of uranium, thorium, lanthanum and europium in carbonaceous shale and monazite by epithermal neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shuenn-Gang; Tsai, Hui-Tuh; Wu, Shaw-Chii [Institute of Nuclear Energy Research, Lung-Tan (Taiwan, Republic of China)

    1981-10-03

    An internal-standard method was applied for the determination of uranium, thorium, lanthanum and europium is carbonaceous shale samples and monazite sand by epithermal neutron activation analysis using gold as an internal standard element. The samples were irradiated in a zero-power reactor at the Institute of Nuclear Energy Research and measured with a high-resolution Ge(Li) detector. The detection limit is 0.1 ppm for uranium and europium, 1 ppm for thorium, 5 ppm for lanthanum, and the realative error of all elements is within +-2.6%.

  20. Method and apparatus for epithermal neutron porosity well logging

    International Nuclear Information System (INIS)

    Hertzog, R.C.; Loomis, W.A.; Wraight, P.

    1991-01-01

    This patent describes a method for investigating the porosity of a subsurface earth formation surrounding a borehole. It comprises repetitively irradiating the borehole and earth formation with discrete bursts of high energy neutrons from a neutron source, which neutrons interact with nuclei of the materials in the borehole and the formation to produce therein populations of epithermal neutrons; detecting the populations of epithermal neutrons at near and far locations in the borehole spaced apart longitudinally by different distances from the neutron source; generating count signals indicative of the magnitudes of the detected epithermal neutron populations at the respective near and far locations; detecting the decay of the epithermal neutron populations following the neutron bursts at least at one location in the borehole and generating signals representative thereof; deriving from the decay signals a signal indicative of the slowing down time of epithermal neutrons in the formation of the at least one location; and deriving from the near and far count signals and the slowing down time signal a measurement signal representative of the porosity of the formation surrounding the borehole inherently compensated for the effects of tool standoff on the responses of the logging tool

  1. Physics of epi-thermal boron neutron capture therapy (epi-thermal BNCT).

    Science.gov (United States)

    Seki, Ryoichi; Wakisaka, Yushi; Morimoto, Nami; Takashina, Masaaki; Koizumi, Masahiko; Toki, Hiroshi; Fukuda, Mitsuhiro

    2017-12-01

    The physics of epi-thermal neutrons in the human body is discussed in the effort to clarify the nature of the unique radiologic properties of boron neutron capture therapy (BNCT). This discussion leads to the computational method of Monte Carlo simulation in BNCT. The method is discussed through two examples based on model phantoms. The physics is kept at an introductory level in the discussion in this tutorial review.

  2. Design of filtered epithermal neutron beams for BNC

    International Nuclear Information System (INIS)

    Greenwood, R.C.

    1986-01-01

    The design principles of filters (installed in nuclear reactors) to provide epithermal neutron beams suitable for use in 10 B Neutron Capture Therapy (BNCT) are reviewed. The goal of such filters is to provide epithermal neutron beams within an energy range of 1 keV to 30 keV with fluxes in excess of 5 x 10 8 neutrons/cm 2 .s, and having acceptably low contaminant fast neutron (> 30 keV) and gamma components. Filters considered for this application include 238 U, Sc, Fe/Al and Al/S. It is shown that in order to achieve a goal epithermal neutron flux of > 5 x 10 8 neutrons/cm 2 .s, such filters must be located in radial beam channels which view essentially the complete reactor core. Based on considerations of estimated epithermal fluxes, cost and availability of materials, and transmitted neutron energy spectrum, it is suggested that a filter consisting of elements of Al, S, Ti and V might prove to be an optimum design for BNCT applications. 13 references, 3 figures, 8 tables

  3. Measurement of epithermal neutrons by a coherent demodulation technique

    CERN Document Server

    Horiuchi, N; Takahashi, H; Kobayashi, H; Harasawa, S

    2000-01-01

    Epithermal neutrons have been measured using a neutron dosimeter via a coherent demodulation technique. This dosimeter consists of CsI(Tl)-photodiode scintillation detectors, four of which are coupled to neutron-gamma converting foils of various sizes. Neutron-gamma converting foils of In, Au and Co materials were used, each of which has a large capture cross section which peaks in the epithermal neutron energy region. The type of foil was selected according to the material properties that best correspond to the energy of the epithermal neutrons to be measured. In addition, the proposed technique was applied using Au-foils in order to measure the Cd ratio. The validity of the proposed technique was examined using an sup 2 sup 4 sup 1 Am-Be source placed in a testing stack of polyethylene blocks, and the results were compared with the theoretical values calculated by the Monte Carlo calculation. Finally, the dosimeter was applied for measuring epithermal neutrons and the Cd ratio in an experimental beam-tube o...

  4. Collimator optimization studies for the new MIT epithermal neutron beam

    International Nuclear Information System (INIS)

    Riley, K.J.; Ali, S.J.; Harling, O.K.

    2000-01-01

    A patient collimator has been designed for the epithermal neutron facility now being commissioned at MIT. Collimator performance both in and out of field was evaluated using the Monte Carlo code MCNP. A two piece design that can accommodate different circular field sizes will be manufactured using a composite lead, epoxy, boron and lithium mixture. (author)

  5. Earth formation pulsed neutron porosity logging system utilizing epithermal neutron and inelastic scattering gamma ray detectors

    International Nuclear Information System (INIS)

    Smith, H.D. Jr.; Smith, M.P.; Schultz, W.E.

    1978-01-01

    An improved pulsed neutron porosity logging system is provided in the present invention. A logging tool provided with a 14 MeV pulsed neutron source, an epithermal neutron detector and an inelastic scattering gamma ray detector is moved through a borehole. The detection of inelastic gamma rays provides a measure of the fast neutron population in the vicinity of the detector. repetitive bursts of neutrons irradiate the earth formation and, during the busts, inelastic gamma rays representative of the fast neutron population is sampled. During the interval between bursts the epithermal neutron population is sampled along with background gamma radiation due to lingering thermal neutrons. the fast and epithermal neutron population measurements are combined to provide a measurement of formation porosity

  6. Design of a permanent Cd-shielded epithermal neutron irradiation site in the Syrian Miniature Neutron Source Reactor

    International Nuclear Information System (INIS)

    Khattab, K.; Haddad, Kh.; Haj-Hassan, H.

    2008-01-01

    A Cd-shield (cylindrical shell 1 mm in thickness, 34 mm in diameter and 180 mm in length) was used to design a permanent epithermal neutron irradiation site for epithermal neutron activation analysis (ENAA) in the Syrian Miniature Neutron Source Reactor (MNSR). This site was achieved by shielding the surface of the aluminum tube of one of the outer irradiation sites. The calculated depression ratio of thermal neutron flux was 1/10. Homogeneity of the neutron flux in the first outer irradiation site has been found numerically using the WIMSD4 and CITATION codes and experimentally by irradiating five short copper wires using the outer irradiation capsule. Good agreement was obtained between the calculated and the measured results of the neutron flux distributions. (author)

  7. Design of a permanent Cd-shielded epithermal neutron irradiation site in the Syrian Miniature Neutron Source Reactor

    International Nuclear Information System (INIS)

    Khattab, K.; Haddad, Kh.; Haj-Hassan, H.

    2009-01-01

    A Cd-shield (cylindrical shell 1 mm in thickness, 34 mm in diameter and 180 mm in length) was used to design a permanent epithermal neutron irradiation site for epithermal neutron activation analysis (ENAA) in the Syrian Miniature Neutron Source Reactor (MNSR). This site was achieved by shielding the surface of the aluminum tube of one of the outer irradiation sites. The calculated depression ratio of thermal neutron flux was 1/10. Homogeneity of the neutron flux in the first outer irradiation site has been found numerically using the WIMSD4 and CITATION codes and experimentally by irradiating five short copper wires using the outer irradiation capsule. Good agreement was obtained between the calculated and the measured results of the neutron flux distributions. (author)

  8. Fundamental symmetry studies at Los Alamos using epithermal neutrons

    International Nuclear Information System (INIS)

    Bowman, C.D.; Bowman, J.D.; Yuan, V.W.

    1988-01-01

    Fundamental symmetry studies using intense polarized beams of epithermal neutrons are underway at the LANSCE facility of the Los Alamos National Laboratory. Three classes of symmetry experiments can be explored: parity violation, and time reversal invariance violation for both parity-violating and parity-conserved observables. The experimental apparatus is described and performance illustrated with examples of recent measurements. Possible improvements in the facilities and prospective experiments are discussed. 15 refs., 10 figs

  9. VLAD for epithermal neutron scattering experiments at large energy transfers

    International Nuclear Information System (INIS)

    Tardocchi, M; Gorini, G; Perelli-Cippo, E; Andreani, C; Imberti, S; Pietropaolo, A; Senesi, R; Rhodes, N R; Schooneveld, E M

    2006-01-01

    The Very Low Angle Detector (VLAD) bank will extend the kinematical region covered by today's epithermal neutron scattering experiments to low momentum transfer ( -1 ) together with large energy transfer 0 -4 0 . In this paper the design of VLAD is presented together with Montecarlo simulations of the detector performances. The results of tests made with prototype VLAD detectors are also presented, confirming the usefulness of the Resonance Detector for measurements at very low scattering angles

  10. Estimation of total as well as bioaccessible levels and average daily dietary intake of iodine from Japanese edible seaweeds by epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Fukushima, M.; Chatt, A.

    2012-01-01

    An epi-thermal instrumental neutron activation analysis (EINAA) method in conjunction with Compton suppression spectrometry (EINAA-CSS) was used for the determination of total iodine in eight different species of edible seaweeds from Japan. This method gave an absolute detection limit of about 2 μg. The accuracy of the method was evaluated using various reference materials and found to be generally in agreement within ±6% of the certified values. The longitudinal distributions of iodine at different growing stages in Japanese sea mustard and tangle seaweeds were investigated. For a 150-cm-high tangle, the highest concentration (5,360 mg/kg) of iodine was found at the root, then decreased slowly to 780 mg/kg in the middle portion (60-75 cm), and increased to 2,300 mg/kg at the apex. On the other hand, for a 190-cm-high sea mustard the highest levels of iodine were found both at the roots (164 mg/kg) and apex (152 mg/kg) with lower values (98 mg/kg) in the middle section. In order to estimate the bioaccessible fraction of iodine, seaweeds were digested by an in vitro enzymolysis method, dietary fibre separated from residue, and both fractions analyzed by EINAA-CSS. The average daily dietary intakes of total (0.14 mg) as well as bioaccessible fraction (0.12 mg) of iodine from the consumption of sea mustards were estimated. (author)

  11. Epithermal/fast neutron cyclic activation analysis for the determination of fluorine in environmental and industrial materials

    International Nuclear Information System (INIS)

    Parry, S.J.; Benzing, R.; Bolstad, K.L.; Steinnes, E.

    2000-01-01

    Pseudocyclic activation analysis (12-second irradiation, 12-second count, 5 cycles, 25 minutes between cycles) is used to determine fluorine in plastic and rubber with detection limits in the range 15-40 mg/kg. The detection of fluorine in materials containing high concentrations of aluminum is improved using the 19 F(n,p) 19 O reaction, induced by fast neutrons, (30-second irradiation, 30-second count, 25-minute decay between cycles). The method was applied to a biomonitoring survey in the vicinity of an aluminum smelter in the Ardal region, Norway. The fluorine concentration in the moss and soil samples could be determined in all samples above the detection limits of 50 and 100 mg/kg, respectively. (author)

  12. Upgrade for the epithermal neutron beam at NRI Rez

    International Nuclear Information System (INIS)

    Marek, M.; Flibor, S.; Viererbl, L.; Burian, J.; Rejchrt, J.; Klupak, V.; Gambarini, G.; Vanossi, E.

    2006-01-01

    The epithermal neutron beam facility designed for pre-clinical neutron capture therapy research has been operated at LVR-15 reactor for more than ten years. The construction of the beam filter has been recently modified especially for the shielding quality of the beam shutter to be improved. The parameters of the upgraded beam were calculated with the MCNP code and a new source term for the NCTPLAN treatment planning software was evaluated. The calculated source term was consequently scaled according to the results of measurements in the free beam and in the 50x50x25 cm 3 water phantom. (author)

  13. Utilization of epithermal neutrons for the determination of molybdenum in the presence of uranium

    International Nuclear Information System (INIS)

    Oliveira Melo, M.A.M. de.

    1984-05-01

    Activation analysis by means of selective activation with epithermal neutrons is proposed for the determination of molybdenum in samples when uranium is present. Instrumental activation analysis with epithermal neutrons is advantageous for the determination of elements with large resonance integral, as compared to its thermal neutron activation cross section. The main reason for using this method is the serious interference caused by 99 Mo produced by fission of 235 U. This effect is strongly reduced by using the epicadmium irradiation technique. The filter efficiency has been investigated by irradiation experiments with bare and cadmium-covered samples. A solvent extraction process for uranium, before irradiation, is proposed to reduce sample background. The determination of Mo in leach samples is proposed in order to support the analytical needs of Figueira and Pocos de Caldas Mineral Prospection Programme of Departamento de Tecnologia Mineral from CDTN/NUCLEBRAS (MG,Brazil). The introduction of activation analysis with epithermal neutrons as a routine analytical tool in CDTN is our main goal. This method represents one more opportunity for exploring the analytical facilities available at TRIGA MARK I IPR-R1 nuclear reactor. (Author) [pt

  14. Epithermal neutron beam adoption for lung and pancreatic cancer treatment by boron neutron capture therapy

    International Nuclear Information System (INIS)

    Matsumoto, Tetsuo; Fukushima, Yuji

    2001-01-01

    The depth-dose distributions were evaluated for possible treatment of both lung and pancreatic cancers using an epithermal neutron beam. The Monte Carlo Neutron Photon (MCNP) calculations showed that physical dose in tumors were 6 and 7 Gy/h, respectively, for lung and pancreas, attaining an epithermal neutron flux of 5 x 10 8 ncm -2 s -1 . The boron concentrations were assumed at 100 ppm and 30 ppm, respectively, for lung and pancreas tumors and normal tissues contains 1/10 tumor concentrations. The dose ratios of tumor to normal tissue were 2.5 and 2.4, respectively, for lung and pancreas. The dose evaluation suggests that BNCT using an epithermal neutron beam could be applied for both lung and pancreatic cancer treatment. (author)

  15. Spherical Harmonics Treatment of Epithermal Neutron Spectra in Reactor lattices

    International Nuclear Information System (INIS)

    Matausek, M.V.

    1972-04-01

    A procedure has been developed to solve the slowing down transport equation for neutrons in a cylindrized reactor lattice cell. Treating the anisotropy of the epithermal neutron flux by the spherical harmonics formalism, which reduces the space-angle-lethargy-dependent transport equation to the matrix integrodifferential equation in space and lethargy, and replacing the lethargy transfer integrals by finite-difference forms, a set of matrix ordinary differential equations, with lethargy and space dependent coefficients, is obtained. In the resonance region this set takes a lower block triangular form and can be directly solved by forward block substitution; in the lethargy range, where the fast fission effects have to be considered, the iterative procedure is introduced. A simple and efficient approximation is then proposed, making possible the analytical solution for the spatial dependence of the spherical harmonics flux moments. The proposed procedure has been numerically examined and approved. Some typical results are presented and discussed. (author)

  16. Development of resonant detectors for epithermal neutron spectroscopy at pulsed neutron sources

    International Nuclear Information System (INIS)

    Tardocchi, M.; Pietropaolo, A.; Senesi, R.; Andreani, C.; Gorini, G.

    2004-01-01

    New perspectives for epithermal neutron spectroscopy are opened by the development of new detectors for inverse geometry time of flight spectrometers at pulsed neutron sources. One example is the Very Low Angle Detector (VLAD) bank planned to be delivered, within the next 4 years, within the eVERDI project, on the neutron spectrometer VESUVIO, at the ISIS pulsed neutron source (UK). VLAD will extend the (q,ω) kinematical region for neutron scattering to low wavefactor transfer (q -1 ) still keeping energy transfer >1 eV, thus allowing the investigations of new experimental studies in condensed matter systems. The technique being developed for detection of epithermal neutrons, within this low q and high-energy transfer region, is the Resonance Detection Technique. In this work, the state of the detector development will be presented with special focus on the results obtained with some prototype detectors, namely YAP scintillators and cadmium-zinc-telluride semiconductors

  17. The resonant detector and its application to epithermal neutron spectroscopy

    International Nuclear Information System (INIS)

    Gorini, G.; Perelli-Cippo, E.; Tardocchi, M.; Andreani, C.; D'Angelo, A.; Pietropaolo, A.; Senesi, R.; Imberti, S.; Bracco, A.; Previtali, E.; Pessina, G.; Rhodes, N.J.; Schooneveld, E.M.

    2004-01-01

    New perspectives for epithermal neutron spectroscopy are being opened by the development of the resonant detector (RD) and its use on inverse geometry time of flight spectrometers at spallation sources. The RD was first proposed in the 1980s and was recently brought to a performance level exceeding conventional neutron-sensitive Li-glass scintillator detectors. It features a photon counter coupled to a neutron analyzer foil. Resonant neutron absorption in the foil results in the emission of prompt gamma rays that are detected in the photon counter. The dimensions of the RD set the spatial resolution that can be achieved, ranging from a fraction of a cm to several cm. It can thus be tailored to the construction of detector arrays of different geometry. The main results of the research on this kind of detector are reported leading to the present optimized RD design based on a combination of YAP scintillation photon counter and uranium or gold analyzer foils. This detector has already been selected for application in the upgrade of the VESUVIO spectrometer on ISIS. A special application is the Very Low Angle Detector (VLAD) bank, which will extend the kinematical region for neutron scattering to low momentum transfer ( -1 ) whilst still keeping energy transfer >1 eV, thus allowing new experimental studies in condensed matter systems. The first results of tests made with prototype VLAD detectors are presented, confirming the usefulness of the RD for measurements at scattering angles as low as 2-5 deg

  18. Dose planning with comparison to in vivo dosimetry for epithermal neutron irradiation of the dog brain

    International Nuclear Information System (INIS)

    Seppaelae, Tiina; Auterinen, Iiro; Aschan, Carita; Seren, Tom; Benczik, Judit; Snellman, Marjatta; Huiskamp, Rene; Ramadan, Usama Abo; Kankaanranta, Leena; Joensuu, Heikki; Savolainen, Sauli

    2002-01-01

    Boron neutron capture therapy (BNCT) is an experimental type of radiotherapy, presently being used to treat glioblastoma and melanoma. To improve patient safety and to determine the radiobiological characteristics of the epithermal neutron beam of Finnish BNCT facility (FiR 1) dose-response studies were carried on the brain of dogs before starting the clinical trials. A dose planning procedure was developed and uncertainties of the epithermal neutron-induced doses were estimated. The accuracy of the method of computing physical doses was assessed by comparing with in vivo dosimetry. Individual radiation dose plans were computed using magnetic resonance images of the heads of 15 Beagle dogs and the computational model of the FiR 1 epithermal neutron beam. For in vivo dosimetry, the thermal neutron fluences were measured using Mn activation foils and the gamma-ray doses with MCP-7s type thermoluminescent detectors placed both on the skin surface of the head and in the oral cavity. The degree of uncertainty of the reference doses at the thermal neutron maximum was estimated using a dose-planning program. The estimated uncertainty (±1 standard deviation) in the total physical reference dose was ±8.9%. The calculated and the measured dose values agreed within the uncertainties at the point of beam entry. The conclusion is that the dose delivery to the tissue can be verified in a practical and reliable fashion by placing an activation dosimeter and a TL detector at the beam entry point on the skin surface with homogeneous tissues below. However, the point doses cannot be calculated correctly in the inhomogeneous area near air cavities of the head model with this type of dose-planning program. This calls for attention in dose planning in human clinical trials in the corresponding areas

  19. Method and apparatus for epithermal neutron decay logging

    International Nuclear Information System (INIS)

    Nelligan, W.B.

    1998-01-01

    The nature of hydrogenous fluids filling the pore spaces in formations surrounding a well bore are determined by irradiating the formations with bursts of high energy neutrons and using the ratio of time-dependent parameters related to the decay of epithermal neutron populations above two different energy levels to provide values indicative of the kind of fluid present, independent of porosity. The measurement above the higher of these energy levels, appr. 0.4eV, indicates the existence of hydrogenous fluid, water and hydrocarbons in the formations. The lower threshold measurement, above appr. 0.15eV, is indicative of the structure of the molecule in which the hydrogen molecule is bound and of the porosity. A pulsed neutron generator in a sonde irradiates the formations with 14meV neutrons and a pair of detectors, one shielded by cadmium, to establish the 0.4eV threshold energy level and the other, shielded by gadolinium, to establish the 0.15eV threshold energy level. Time related parameters of the count rate information, e.g. the decay constants, provided by each detector are derived. The ratio of the respective parameters is used to identify the type of fluid in the information, independent of porosity. The method and apparatus can determine water saturation, i.e. percentage of water in the formation fluid and can identify specific types of hydrocarbons under 100% hydrocarbon saturation conditions. 8 figs

  20. Upgrades of the epithermal neutron beam at the Brookhaven Medical Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hungyuan B.; Brugger, R.M.; Rorer, D.C.

    1994-12-31

    The first epithermal neutron beam at the Brookhaven Medical Research Reactor (BMRR) was installed in 1988 and produced a neutron beam that was satisfactory for the development of NCT with epithermal neutrons. This beam was used routinely until 1992 when the beam was upgraded by rearranging fuel elements in the reactor core to achieve a 50% increase in usable flux. Next, after computer modeling studies, it was proposed that the Al and Al{sub 2}O{sub 3} moderator material in the shutter that produced the epithermal neutrons could be rearranged to enhance the beam further. However, this modification was not started because a better option appeared, namely to use fission plates to move the source of fission neutrons closer to the moderator and the patient irradiation position to achieve more efficient moderation and production of epithermal neutrons. A fission plate converter (FPC) source has been designed recently and, to test the concept, implementation of this upgrade has started. The predicted beam parameters will be 12 x 10{sup 9} n{sub epi}/cm{sup 2}sec accompanying with doses from fast neutrons and gamma rays per epithermal neutron of 2.8 x 10{sup -11} and < 1 x 10{sup -11} cGycm{sup 2}/n, respectively, and a current-to-flux ratio of epithermal neutrons of 0.78. This conversion could be completed by late 1996.

  1. MCNP study for epithermal neutron irradiation of an isolated liver at the Finnish BNCT facility.

    Science.gov (United States)

    Kotiluoto, P; Auterinen, I

    2004-11-01

    A successful boron neutron capture treatment (BNCT) of a patient with multiple liver metastases has been first given in Italy, by placing the removed organ into the thermal neutron column of the Triga research reactor of the University of Pavia. In Finland, FiR 1 Triga reactor with an epithermal neutron beam well suited for BNCT has been extensively used to irradiate patients with brain tumors such as glioblastoma and recently also head and neck tumors. In this work we have studied by MCNP Monte Carlo simulations, whether it would be beneficial to treat an isolated liver with epithermal neutrons instead of thermal ones. The results show, that the epithermal field penetrates deeper into the liver and creates a build-up distribution of the boron dose. Our results strongly encourage further studying of irradiation arrangement of an isolated liver with epithermal neutron fields.

  2. Measurement of the neutron flux distributions, epithermal index, Westcott thermal neutron flux in the irradiation capsules of hydraulic conveyer (Hyd) and pneumatic tubes (Pn) facilities of the KUR

    International Nuclear Information System (INIS)

    Chatani, Hiroshi

    2001-05-01

    The reactions of Au(n, γ) 198 Au and Ti(n, p) 47 or 48 Sc were used for the measurements of the thermal and epithermal (thermal + epithermal) and the fast neutron flux distributions, respectively. In the case of Hyd (Hydraulic conveyer), the thermal + epithermal and fast neutron flux distributions in the horizontal direction in the capsule are especially flat; the distortion of the fluxes are 0.6% and 5.4%, respectively. However, these neutron fluxes in the vertical direction are low at the top and high at the bottom of the capsule. These differences between the top and bottom are 14% for both distributions. On the other hand, in polyethylene capsules of Pn-1, 2, 3 (Pneumatic tubes Nos. 1, 2, 3), in contrast with Hyd, these neutron flux distributions in the horizontal direction have gradients of 8 - 18% per 2.5 cm diameter, and those on the vertical axis have a distortion of approximately 5%. The strength of the epithermal dE/E component relative to the neutron density including both thermal and epithermal neutrons, i.e., the epithermal index, for the hydraulic conveyer (Hyd) and pneumatic tube No.2 (Pn-2), in which the irradiation experiments can be achieved, are determined by the multiple foil activation method using the reactions of Au(n, γ) 198 Au and Co(n, γ) 60(m+g) Co. The epithermal index observed in an aluminum capsule of Hyd is 0.034-0.04, and the Westcott thermal neutron flux is 1.2x10 14 cm -2 sec -1 at approximately 1 cm above the bottom. The epithermal index in a Pn-2 polyethylene capsule was measured by not only the multiple foil activation method but also the Cd-ratio method in which the Au(n, γ) 198 Au reaction in a cadmium cover is also used. The epithermal index is 0.045 - 0.055, and the thermal neutron flux is 1.8x10 13 cm -2 sec -1 . (J.P.N.)

  3. Neutron kinetics in moderators and SNM detection through epithermal-neutron-induced fissions

    Energy Technology Data Exchange (ETDEWEB)

    Gozani, Tsahi, E-mail: tgmaven@gmail.com [1050 Harriet St., Palo Alto, CA 94301 (United States); King, Michael J. [Rapiscan Laboratories Inc., 520 Almanor Ave., Sunnyvale, CA 94085 (United States)

    2016-01-01

    Extension of the well-established Differential Die Away Analysis (DDAA) into a faster time domain, where more penetrating epithermal neutrons induce fissions, is proposed and demonstrated via simulations and experiments. In the proposed method the fissions stimulated by thermal, epithermal and even higher-energy neutrons are measured after injection of a narrow pulse of high-energy 14 MeV (d,T) or 2.5 MeV (d,D) source neutrons, appropriately moderated. The ability to measure these fissions stems from the inherent correlation of neutron energy and time (“E–T” correlation) during the process of slowing down of high-energy source neutrons in common moderating materials such as hydrogenous compounds (e.g., polyethylene), heavy water, beryllium and graphite. The kinetic behavior following injection of a delta-function-shaped pulse (in time) of 14 MeV neutrons into such moderators is studied employing MCNPX simulations and, when applicable, some simple “one-group” models. These calculations served as a guide for the design of a source moderator which was used in experiments. Qualitative relationships between slowing-down time after the pulse and the prevailing neutron energy are discussed. A laboratory system consisting of a 14 MeV neutron generator, a polyethylene-reflected Be moderator, a liquid scintillator with pulse-shape discrimination (PSD) and a two-parameter E–T data acquisition system was set up to measure prompt neutron and delayed gamma-ray fission signatures in a 19.5% enriched LEU sample. The measured time behavior of thermal and epithermal neutron fission signals agreed well with the detailed simulations. The laboratory system can readily be redesigned and deployed as a mobile inspection system for SNM in, e.g., cars and vans. A strong pulsed neutron generator with narrow pulse (<75 ns) at a reasonably high pulse frequency could make the high-energy neutron induced fission modality a realizable SNM detection technique.

  4. A new position-sensitive transmission detector for epithermal neutron imaging

    International Nuclear Information System (INIS)

    Schooneveld, E M; Kockelmann, W; Rhodes, N; Tardocchi, M; Gorini, G; Perelli Cippo, E; Nakamura, T; Postma, H; Schillebeeckx, P

    2009-01-01

    A new neutron resonant transmission (NRT) detector for epithermal neutron imaging has been designed and built for the ANCIENT CHARM project, which is developing a set of complementary neutron imaging methods for analysis of cultural heritage objects. One of the techniques being exploited is NRT with the aim of performing bulk elemental analysis. The 16-pixel prototype NRT detector consists of independent crystals of 2 x 2 mm pixel size, which allow for 2D position-sensitive transmission measurements with epithermal neutrons. First results obtained at the ISIS pulsed spallation neutron source are presented. (fast track communication)

  5. Characterization of the γ background in epithermal neutron scattering measurements at pulsed neutron sources

    International Nuclear Information System (INIS)

    Pietropaolo, A.; Tardocchi, M.; Schooneveld, E.M.; Senesi, R.

    2006-01-01

    This paper reports the characterization of the different components of the γ background in epithermal neutron scattering experiments at pulsed neutron sources. The measurements were performed on the VESUVIO spectrometer at ISIS spallation neutron source. These measurements, carried out with a high purity germanium detector, aim to provide detailed information for the investigation of the effect of the γ energy discrimination on the signal-to-background ratio. It is shown that the γ background is produced by different sources that can be identified with their relative time structure and relative weight

  6. Experimental demonstration of a compact epithermal neutron source based on a high power laser

    Science.gov (United States)

    Mirfayzi, S. R.; Alejo, A.; Ahmed, H.; Raspino, D.; Ansell, S.; Wilson, L. A.; Armstrong, C.; Butler, N. M. H.; Clarke, R. J.; Higginson, A.; Kelleher, J.; Murphy, C. D.; Notley, M.; Rusby, D. R.; Schooneveld, E.; Borghesi, M.; McKenna, P.; Rhodes, N. J.; Neely, D.; Brenner, C. M.; Kar, S.

    2017-07-01

    Epithermal neutrons from pulsed-spallation sources have revolutionised neutron science allowing scientists to acquire new insight into the structure and properties of matter. Here, we demonstrate that laser driven fast (˜MeV) neutrons can be efficiently moderated to epithermal energies with intrinsically short burst durations. In a proof-of-principle experiment using a 100 TW laser, a significant epithermal neutron flux of the order of 105 n/sr/pulse in the energy range of 0.5-300 eV was measured, produced by a compact moderator deployed downstream of the laser-driven fast neutron source. The moderator used in the campaign was specifically designed, by the help of MCNPX simulations, for an efficient and directional moderation of the fast neutron spectrum produced by a laser driven source.

  7. Cs-137 geochronology, epithermal neutron activation analysis, and principal component analysis of heavy metals pollution of the Black Sea anoxic continental shelf sediments

    Science.gov (United States)

    Duliu, O. G.; Cristache, C.; Oaie, G.; Culicov, O. A.; Frontasyeva, M. V.

    2009-04-01

    Anthropogenic Cs-137 Gamma-ray Spectroscopy assay (GrSA) performed at the National Institute of Research and Development for Physics and Nuclear Engineering - Bucharest (Romania) in correlation with Epithermal Neutrons Activation Analysis (ENAA) performed at the Joint Institute of Nuclear Researches - Dubna (Russia) were used to investigate a 50 cm core containing unconsolidated sediments collected at a depth of 600 m off Romanian town of Constantza, located in the anoxic zone of the Black Sea Continental Shelf. A digital radiography showed the presence of about 265 distinct laminae, 1 to 3 mm thick, a fact attesting a stationary sedimentary process, completely free of bioturbation. After being radiographed, the core was sliced into 45 segments whose thickness gradually increased from 0.5 to 5 cm, such that the minimum thickness corresponded to the upper part of the core. From each segment two aliquots of about 0.5 g and 50 g were extracted for subsequent ENAA and Cs-137 GrSA. The Cs-137 vertical profile evidenced two maxima, one of them was very sharp and localized at a depth of 1 cm and the other very broad, almost undistinguished at about 8 cm depth, the first one being attributed to 1986 Chernobyl accident. Based on these date, we have estimated a sedimentation ratio of about 0.5 mm/year, value taken as reference for further assessment of recent pollution history. By means of ENAA we have determined the vertical content of five presumed pollutants, e.i. Zn, As, Br, Sn and Sb and of Sc, as natural, nonpolluting element. In the first case, all five elements presented a more or less similar vertical profile consisting of an almost exponential decrease for the first 10 cm below sediment surface followed by a plateau until the core base, i.e. 50 cm below surface, dependency better described by the equation: c(z) = c0 [1+k exp (-z/Z)] (1) where: where c(z) represents the concentration vertical profile; z represents depth (in absolute value); c0 represents the plateau

  8. Optimization study for an epithermal neutron beam for boron neutron capture therapy at the University of Virginia Research Reactor

    International Nuclear Information System (INIS)

    Burns, T.D. Jr.

    1995-05-01

    The non-surgical brain cancer treatment modality, Boron Neutron Capture Therapy (BNCT), requires the use of an epithermal neutron beam. This purpose of this thesis was to design an epithermal neutron beam at the University of Virginia Research Reactor (UVAR) suitable for BNCT applications. A suitable epithermal neutron beam for BNCT must have minimal fast neutron and gamma radiation contamination, and yet retain an appreciable intensity. The low power of the UVAR core makes reaching a balance between beam quality and intensity a very challenging design endeavor. The MCNP monte carlo neutron transport code was used to develop an equivalent core radiation source, and to perform the subsequent neutron transport calculations necessary for beam model analysis and development. The code accuracy was validated by benchmarking output against experimental criticality measurements. An epithermal beam was designed for the UVAR, with performance characteristics comparable to beams at facilities with cores of higher power. The epithermal neutron intensity of this beam is 2.2 x 10 8 n/cm 2 · s. The fast neutron and gamma radiation KERMA factors are 10 x 10 -11 cGy·cm 2 /n epi and 20 x 10 -11 cGy·cm 2 /n epi , respectively, and the current-to-flux ratio is 0.85. This thesis has shown that the UVAR has the capability to provide BNCT treatments, however the performance characteristics of the final beam of this study were limited by the low core power

  9. Characterisation of the epithermal neutron irradiation facility at the Portuguese research reactor using MCNP.

    Science.gov (United States)

    Beasley, D G; Fernandes, A C; Santos, J P; Ramos, A R; Marques, J G; King, A

    2015-05-01

    The radiation field at the epithermal beamline and irradiation chamber installed at the Portuguese Research Reactor (RPI) at the Campus Tecnológico e Nuclear of Instituto Superior Técnico was characterised in the context of Prompt Gamma Neutron Activation Analysis (PGNAA) applications. Radiographic films, activation foils and thermoluminescence dosimeters were used to measure the neutron fluence and photon dose rates in the irradiation chamber. A fixed-source MCNPX model of the beamline and chamber was developed and compared to measurements in the first step towards planning a new irradiation chamber. The high photon background from the reactor results in the saturation of the detector and the current facility configuration yields an intrinsic insensitivity to various elements of interest for PGNAA. These will be addressed in future developments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. The determination of self-powered neutron detector sensitivity on thermal and epithermal neutron flux densities

    International Nuclear Information System (INIS)

    Erben, O.

    1980-01-01

    The coefficients of thermal and epithermal neutron flux density depression and self-shielding for the SPN detectors with vanadium, rhodium, silver and cobalt emitters are presented, (for cobalt SPN detectors the functions describing the absorbtion of neutrons along the emitter cross-section are also shown). Using these coefficients and previously published beta particle escape efficiencies, sensitivities are determined for the principal types of detectors produced by Les Cables de Lyon and SODERN companies. The experiments and their results verifying the validity of the theoretical work are described. (author)

  11. 8-group relative delayed neutron yields for epithermal neutron induced fission of 235U and 239Pu

    International Nuclear Information System (INIS)

    Piksaikin, V.M.; Kazakov, L.E.; Isaev, S.G.; Korolev, G.G.; Roshchenko, V.A.; Tertychnyj, R.G

    2002-01-01

    An 8-group representation of relative delayed neutron yields was obtained for epithermal neutron induced fission of 235 U and 239 Pu. These data were compared with ENDF/B-VI data in terms of the average half- life of the delayed neutron precursors and on the basis of the dependence of reactivity on the asymptotic period. (author)

  12. Experiences of reconstruction of the epithermal neutron beam at THOR

    International Nuclear Information System (INIS)

    Liu Hongming; Hsu Pinchieh; Liu Chaochin; Jiang Shianghuei; Liu Yenwan Hsueh; Kai Jijung

    2006-01-01

    Tsing Hua Open-pool Reactor (THOR) had completed the renovation for an epithermal neutron beam in August 2004. The major tasks for this renovation were moderator/filter design and assembling, and concrete cutting for a better beam quality and larger irradiation room. Besides moderator/filter design, the associated works involved radiation monitoring, structure analysis, and shielding design. The radiation monitoring was performed to predict the probable accumulated dose for the workers involved in this reconstruction project. Special shielding design and construction processes were adopted to lower the radiation level and the probable accumulated dose for the workers. Before concrete cutting, structure analysis based on SAP-2000 code was performed to assure the structure is safe from the earthquake in Taiwan. A wall saw was then used for concrete cutting to enlarge the space of the irradiation room. Moderator/filter components were assembled on a trolley outside the beam exit prior to installation, which can effectively reduce the duration of a worker staying inside the reconstruction area and thereby reduce the accumulated dose. The shielding for the irradiation room was designed based on MCNP simulation using a pre-calculated source plane at the beam exit. The thickness of the concrete (density=3 g/cm 3 ) of the walls and ceiling of the irradiation room were designed to be 100cm. On-going tasks include beam parameters measurement and in vitro/ in vivo study and calibration of treatment planning system, with the hope that the team can be ready for clinical trials in 2-3 years. (author)

  13. A new position-sensitive detector for thermal and epithermal neutrons

    International Nuclear Information System (INIS)

    Jeavons, A.P.; Ford, N.L.; Lindberg, B.; Sachot, R.

    1977-01-01

    A new two-dimensional position-sensitive neutron detector is described. It is based on (n,γ) neutron resonance capture in a foil with subsequent detection of internal conversion electrons with a high-density proportional chamber. Large-area detectors with a 1 mm spatial resolution are feasible. A detection efficiency of 50% is possible for thermal neutrons using gadolinium-157 foil and for epithermal neutrons using hafnium-177. (Auth.)

  14. Dependence of the Ratio between the Resonance Integral and Thermal Neutron Cross Section on the Deviation of the Epithermal Neutron Spectrum from the 1/E Law

    International Nuclear Information System (INIS)

    Soliman, N.F.

    2012-01-01

    In k 0 - Neutron Activation Analysis (k 0 -NAA), the conversion from the tabulated Q 0 (ratio of the resonance integral to thermal neutron cross-section)to Q 0 (α) (α is the shape factor of the epithermal neutron flux, indicating the deviation of the epithermal neutron spectrum from the ideal 1/E shape) are calculated using a FORTRAN program. The calculations are done for most elements that can be detected by neutron activation using different values of the parameter (α) ranging from -0.1≤α≤+0.1. The obtained data are used to study the dependence of the values (α) on the irradiation position factor in (k 0 -NAA)equation for some selected isotopes differ in their resonance energy and its Q 0 values. The results show that, the irradiation factor is affective mainly for low thermal tro epithermal flux ratio f especially for Q 0 value greater than 50. so consequently determining the irradiation parameters α value is not needed for irradiation positions that rich with thermal neutron. But for high f values the irradiation position factor should be taken into account. On the other hand the constructed FORTRAN program can be used to calculate the value Q 0 (α) directly for different value of α

  15. Detector for imaging and dosimetry of laser-driven epithermal neutrons by alpha conversion

    Science.gov (United States)

    Mirfayzi, S. R.; Alejo, A.; Ahmed, H.; Wilson, L. A.; Ansell, S.; Armstrong, C.; Butler, N. M. H.; Clarke, R. J.; Higginson, A.; Notley, M.; Raspino, D.; Rusby, D. R.; Borghesi, M.; Rhodes, N. J.; McKenna, P.; Neely, D.; Brenner, C. M.; Kar, S.

    2016-10-01

    An epithermal neutron imager based on detecting alpha particles created via boron neutron capture mechanism is discussed. The diagnostic mainly consists of a mm thick Boron Nitride (BN) sheet (as an alpha converter) in contact with a non-borated cellulose nitride film (LR115 type-II) detector. While the BN absorbs the neutrons in the thermal and epithermal ranges, the fast neutrons register insignificantly on the detector due to their low neutron capture and recoil cross-sections. The use of solid-state nuclear track detectors (SSNTD), unlike image plates, micro-channel plates and scintillators, provide safeguard from the x-rays, gamma-rays and electrons. The diagnostic was tested on a proof-of-principle basis, in front of a laser driven source of moderated neutrons, which suggests the potential of using this diagnostic (BN+SSNTD) for dosimetry and imaging applications.

  16. Study on the dose distribution of the mixed field with thermal and epi-thermal neutrons for neutron capture therapy

    International Nuclear Information System (INIS)

    Kobayashi, Tooru; Sakurai, Yoshinori; Kanda, Keiji

    1994-01-01

    Simulation calculations using DOT 3.5 were carried out in order to confirm the characteristics of depth-dependent dose distribution in water phantom dependent on incident neutron energy. The epithermal neutrons mixed to thermal neutron field is effective improving the thermal neutron depth-dose distribution for neutron capture therapy. A feasibility study on the neutron energy spectrum shifter was performed using ANISN-JR for the KUR Heavy Water Facility. The design of the neutron spectrum shifter is feasible, without reducing the performance as a thermal neutron irradiation field. (author)

  17. Advances on detectors for low-angle scattering of epithermal neutrons

    International Nuclear Information System (INIS)

    Perelli Cippo, E; Gorini, G; Tardocchi, M; Andreani, C; Pietropaolo, A; Senesi, R; Rhodes, N J; Schoonveld, E M

    2008-01-01

    The Very Low Angle Detector (VLAD) installed at the ISIS spallation neutron source is a novel instrument for epithermal neutron scattering with a range of applications in solid state physics. VLAD extends the kinematical space of the VESUVIO spectrometer to low momentum transfers at neutron energies above 1 eV. Measurements at scattering angles as low as 1° have been made with limitations due to the achievable signal/background ratio. (technical design note)

  18. YAP scintillators for resonant detection of epithermal neutrons at pulsed neutron sources

    International Nuclear Information System (INIS)

    Tardocchi, M.; Gorini, G.; Pietropaolo, A.; Andreani, C.; Senesi, R.; Rhodes, N.; Schooneveld, E. M.

    2004-01-01

    Recent studies indicate the resonance detector (RD) technique as an interesting approach for neutron spectroscopy in the electron volt energy region. This work summarizes the results of a series of experiments where RD consisting of YAlO 3 (YAP) scintillators were used to detect scattered neutrons with energy in the range 1-200 eV. The response of YAP scintillators to radiative capture γ emission from a 238 U analyzer foil was characterized in a series of experiments performed on the VESUVIO spectrometer at the ISIS pulsed neutron source. In these experiments a biparametric data acquisition allowed the simultaneous measurements of both neutron time-of-flight and γ pulse height (energy) spectra. The analysis of the γ pulse height and neutron time of flight spectra permitted to identify and distinguish the signal and background components. These measurements showed that a significant improvement in the signal-to-background ratio can be achieved by setting a lower level discrimination on the pulse height at about 600 keV equivalent photon energy. Present results strongly indicate YAP scintillators as the ideal candidate for neutron scattering studies with epithermal neutrons at both very low (<5 deg.) and intermediate scattering angles

  19. An accelerator-based epithermal photoneutron source for boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Hannah E. [Georgia Inst. of Technology, Atlanta, GA (United States)

    1996-04-01

    Boron neutron capture therapy is an experimental binary cancer radiotherapy modality in which a boronated pharmaceutical that preferentially accumulates in malignant tissue is first administered, followed by exposing the tissue in the treatment volume to a thermal neutron field. Current usable beams are reactor-based but a viable alternative is the production of an epithermal neutron beam from an accelerator. Current literature cites various proposed accelerator-based designs, most of which are based on proton beams with beryllium or lithium targets. This dissertation examines the efficacy of a novel approach to BNCT treatments that incorporates an electron linear accelerator in the production of a photoneutron source. This source may help to resolve some of the present concerns associated with accelerator sources, including that of target cooling. The photoneutron production process is discussed as a possible alternate source of neutrons for eventual BNCT treatments for cancer. A conceptual design to produce epithermal photoneutrons by high photons (due to bremsstrahlung) impinging on deuterium targets is presented along with computational and experimental neutron production data. A clinically acceptable filtered epithermal neutron flux on the order of 107 neutrons per second per milliampere of electron current is shown to be obtainable. Additionally, the neutron beam is modified and characterized for BNCT applications by employing two unique moderating materials (an Al/AlF3 composite and a stacked Al/Teflon design) at various incident electron energies.

  20. An accelerator-based epithermal photoneutron source for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Mitchell, H.E.

    1996-04-01

    Boron neutron capture therapy is an experimental binary cancer radiotherapy modality in which a boronated pharmaceutical that preferentially accumulates in malignant tissue is first administered, followed by exposing the tissue in the treatment volume to a thermal neutron field. Current usable beams are reactor-based but a viable alternative is the production of an epithermal neutron beam from an accelerator. Current literature cites various proposed accelerator-based designs, most of which are based on proton beams with beryllium or lithium targets. This dissertation examines the efficacy of a novel approach to BNCT treatments that incorporates an electron linear accelerator in the production of a photoneutron source. This source may help to resolve some of the present concerns associated with accelerator sources, including that of target cooling. The photoneutron production process is discussed as a possible alternate source of neutrons for eventual BNCT treatments for cancer. A conceptual design to produce epithermal photoneutrons by high photons (due to bremsstrahlung) impinging on deuterium targets is presented along with computational and experimental neutron production data. A clinically acceptable filtered epithermal neutron flux on the order of 10 7 neutrons per second per milliampere of electron current is shown to be obtainable. Additionally, the neutron beam is modified and characterized for BNCT applications by employing two unique moderating materials (an Al/AlF 3 composite and a stacked Al/Teflon design) at various incident electron energies

  1. Boron neutron capture therapy (BNCT). Recent aspect, a change from thermal neutron to epithermal neutron beam and a new protocol

    International Nuclear Information System (INIS)

    Nakagawa, Yoshinobu

    1999-01-01

    Since 1968, One-hundred seventy three patients with glioblastoma (n=81), anaplastic astrocytoma (n=44), low grade astrocytoma (n=16) or other types of tumor (n=32) were treated by boron-neutron capture therapy (BNCT) using a combination of thermal neutron and BSH in 5 reactors (HTR n=13, JRR-3 n=1, MuITR n=98, KUR n=28, JRR-2 n=33). Out of 101 patients with glioma treated by BNCT under the recent protocol, 33 (10 glioblastoma, 14 anaplastic astrocytoma, 9 low grade astrocytoma) patients lived or have lived longer than 3 years. Nine of these 33 lived or have lived longer than 10 years. According to the retrospective analysis, the important factors related to the clinical results were tumor dose radiation dose and maximum radiation dose in thermal brain cortex. The result was not satisfied as it was expected. Then, we decided to introduce mixed beams which contain thermal neutron and epithermal neutron beams. KUR was reconstructed in 1996 and developed to be available to use mixed beams. Following the shutdown of the JRR-2, JRR-4 was renewed for medical use in 1998. Both reactors have capacity to yield thermal neutron beam, epithermal neutron beam and mixed beams. The development of the neutron source lead us to make a new protocol. (author)

  2. Evaluation for activities of component of Cyclotron-Based Epithermal Neutron Source (C-BENS) and the surface of concrete wall in irradiation room

    Energy Technology Data Exchange (ETDEWEB)

    Imoto, M., E-mail: masayuki.imoto@gmail.com [Graduate School of Engineering, Kyoto University, Kyoto 606-8501 (Japan); Tanaka, H. [Research Reactor Institute, Kyoto University, Osaka 590-0494 (Japan); Fujita, K.; Mitsumoto, T. [Sumitomo Heavy Industries, Ltd., Tokyo 141-6025 (Japan); Ono, K.; Maruhashi, A.; Sakurai, Y. [Research Reactor Institute, Kyoto University, Osaka 590-0494 (Japan)

    2011-12-15

    The workers employed in BNCT must enter the irradiation room just after an irradiation under the condition of remaining activities. To reduce the radiation exposure for the workers, it is important to identify the origins of the activities. In this research, the activities induced on the concrete wall surface were evaluated using MCNP-5 and the measurement results of thermal neutron distribution. Furthermore, the radioisotopes produced in the moderator were identified with a High Purity Germanium detector. It was found that the activities of the wall were mainly caused by {sup 46}Sc, {sup 60}Co and {sup 152}Eu, and that {sup 24}Na and {sup 56}Mn were mainly produced in the moderator.

  3. Thermal, epithermal and thermalized neutron attenuation properties of ilmenite-serpentine heat resistant concrete shield

    International Nuclear Information System (INIS)

    Kany, A.M.I.; El-Gohary, M.I.; Kamal, S.M.

    1994-01-01

    Experimental measurements were carried out to study the attenuation properties of low-energy neutrons transmitted through unheated and preheated barriers of heavy-weight, highly hydrated and heat-resistant concrete shields. The concrete shields under investigation have been prepared from naturally occurring ilmenite and serpentine Egyptian ores. A collimated beam obtained from an Am-Be source was used as a source of neutrons, while the measurements of total thermal, epithermal, and thermalized neutron fluxes were performed using a BF-3 detector, multichannel analyzer and Cd filter. Results show that the ilmenite-serpentine concrete proved to be a better thermal, epithermal and thermalized neutron attenuator than the ordinary concrete especially at a high temperature of concrete exposure. (Author)

  4. Epithermal neutron beam for BNCT research at the Washington State University TRIGA research reactor

    International Nuclear Information System (INIS)

    Nigg, D.W.; Venhuizen, J.R.; Wheeler, F.J.; Wemple, C.A.; Tripard, G.E.; Gavin, P.R.

    2000-01-01

    A new epithermal-neutron beam facility for BNCT (Boron Neutron Capture Therapy) research and boronated agent screening in animal models is in the final stages of construction at Washington State University (WSU). A key distinguishing feature of the design is the incorporation of a new, high-efficiency, neutron moderating and filtering material, Fluental, developed by the Technical Research Centre of Finland. An additional key feature is the provision for adjustable filter-moderator thickness to systematically explore the radiobiological consequences of increasing the fast-neutron contamination above the nominal value associated with the baseline system. (author)

  5. Theoretical and experimental study of collectrons for epithermal neutron flux in reactors

    International Nuclear Information System (INIS)

    Agu, M.N.

    1986-01-01

    A theoretical study of nuclear reactions and electric charge displacements arising in sensitivity to thermal and epithermal neutrons in collectrons allowed a computer code conception. Collectrons in Rhodium, Silver, Cobalt, Hafnium, Erbium, Gadolinium and Holmium have been tested in different radiation fields given by neutron or gamma filters irradiated in different places of Melusine and Siloe reactors. Some emitters were covered with different steel, nickel or zircaloy thicknesses. Theoretical and experimental results are consistent; that validate the computer code and show possibilities and necessity of covering collectron emitters to reduce or cancel the gamma sensitivity and to improve response instantaneity. A selective measurement of epithermal neutron flux can by this way, made by associating two types of collectrons [fr

  6. Installation and testing of an optimized epithermal neutron beam at the Brookhaven Medical Research Reactor (BMRR)

    Energy Technology Data Exchange (ETDEWEB)

    Fairchild, R.G.; Kalef-Ezra, J.; Saraf, S.K.; Fiarman, S.; Ramsey, E.; Wielopolski, L.; Laster, B.; Wheeler, F. (Brookhaven National Lab., Upton, NY (USA); Ioannina Univ. (Greece); Brookhaven National Lab., Upton, NY (USA); State Univ. of New York, Stony Brook, NY (USA). Health Science Center; Brookhaven National Lab., Upton, NY (USA); EG and G Idaho, Inc., Idaho Falls, ID (USA))

    1989-01-01

    Various calculations indicate that an optimized epithermal neutron beam can be produced by moderating fission neutrons either with a combination of Al and D{sub 2}O, or with Al{sub 2}O{sub 3}. We have designed, installed and tested an Al{sub 2}O{sub 3} moderated epithermal neutron beam at the Brookhaven Medical Research Reactor (BMRR). The epithermal neutron fluence rate of 1.8 {times} 10{sup 9} n/cm{sup 2}-sec produces a peak thermal neutron fluence rate of 1.9 to 2.8 {times} 10{sup 9} n/cm{sup 2}-sec in a tissue equivalent (TE) phantom head, depending on the configuration. Thus a single therapy treatment of 5 {times} 10{sup 12} n/cm{sup 2} can be delivered in 30--45 minutes. All irradiation times are given for a BMRR power of 3 MW, which is the highest power which can be delivered continuously. 18 refs., 8 figs., 4 tabs.

  7. Power Burst Reactor Facility as an epithermal neutron source for brain cancer therapy

    International Nuclear Information System (INIS)

    Wheeler, F.J.

    1986-01-01

    The Power Burst Facility (PBF) reactor is considered for modification to provide an intense, clean source of intermediate-energy (epithermal) neutrons desirable for clinical studies of neutron capture therapy (NCT) for malignant tumors. The modifications include partial replacement of the reflector, installation of a neutron-moderating, shifting region, additional shielding, and penetration of the present concrete shield with a collimating (and optionally) filtering region. The studies have indicated that the reactor, after these modifications, will be safely operable at full power (28 MW) within the acceptable limits of the plant protection systems. The neutron beam exiting from the collimator port is predicted to be of sufficient intensity (approx.10 10 neutrons/cm 2 -s) to provide therapeutic doses in very short irradiation times. The beam would be relatively free of undesirable fast neutrons, thermal neutrons and gamma rays. The calculated neutron energy spectrum and associated gamma rays in the beam were provided as input in simulation studies that used a computer model of a patient with a brain tumor to determine predicted dose rates to the tumor and healthy tissue. The results of this conceptual study indicate an intense, clean beam of epithermal neutrons for NCT clinical trials is attainable in the PBF facility with properly engineered design modifications. 9 refs., 11 figs., 3 tabs

  8. Epithermal neutron flux in the experimental channels of the RA reactor; Fluks epitermalnih neutrona u eksperimentalnim kanalima reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N; Dobrosavljevic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    Epithermal neutron flux was determined by measuring the cadmium ratio from activation analysis of gold and indium foils. Irradiation was done in experimental channels VK-5, VK-2, VK-7, VK-0, VK-HS next to the core, and next to the fuels elements. Activation of bare foils and foils covered by 0.8 and 1.0 mm thick cadmium foils was done simultaneously. Activity was measured by GM counter. Corrections were done for resonant neutrons self-absorption since the foils used were too thick concerning most important resonances of gold and indium. Final results were presented as spectrum factor r for their direct use in determining the effective neutron cross sections.

  9. A spin-transport system for a longitudinally polarized epithermal neutron beam

    International Nuclear Information System (INIS)

    Crawford, B.E.; Bowman, J.D.; Penttilae, S.I.; Roberson, N.R.

    2001-01-01

    The TRIPLE (Time Reversal and Parity at Low Energies) collaboration uses a polarized epithermal neutron beam and a capture γ-ray detector to study parity violation in neutron-nucleus reactions. In order to preserve the spin polarization of the neutrons as they travel the 60-m path to the target, the beam pipes are wrapped with wire to produce a solenoidal magnetic field of about 10 G along the beam direction. The flanges and bellows between sections of the beam pipe cause gaps in the windings which in turn produce radial fields that can depolarize the neutron spins. A computer code has been developed that numerically evaluates the effect of these gaps on the polarization. A measurement of the neutron depolarization for neutrons in the actual spin-transport system agrees with a calculation of the neutron depolarization for the TRIPLE system. Features that will aid in designing similar spin-transport systems are discussed

  10. ESR-dosimetry in thermal and epithermal neutron fields for application in boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, Tobias

    2016-01-22

    Dosimetry is essential for every form of radiotherapy. In Boron Neutron Capture Therapy (BNCT) mixed neutron and gamma fields have to be considered. Dose is deposited in different neutron interactions with elements in the penetrated tissue and by gamma particles, which are always part of a neutron field. The therapeutic dose in BNCT is deposited by densely ionising particles, originating from the fragmentation of the isotope boron-10 after capture of a thermal neutron. Despite being investigated for decades, dosimetry in neutron beams or fields for BNCT remains complex, due to the variety in type and energy of the secondary particles. Today usually ionisation chambers combined with metal foils are used. The applied techniques require extensive effort and are time consuming, while the resulting uncertainties remain high. Consequently, the investigation of more effective techniques or alternative dosimeters is an important field of research. In this work the possibilities of ESR-dosimeters in those fields have been investigated. Certain materials, such as alanine, generate stable radicals upon irradiation. Using Electron Spin Resonance (ESR) spectrometry the amount of radicals, which is proportional to absorbed dose, can be quantified. Different ESR detector materials have been irradiated in the thermal neutron field of the research reactor TRIGA research reactor in Mainz, Germany, with five setups, generating different secondary particle spectra. Further irradiations have been conducted in two epithermal neutron beams. The detector response, however, strongly depends on the dose depositing particle type and energy. It is hence necessary to accompany measurements by computational modelling and simulation. In this work the Monte Carlo code FLUKA was used to calculate absorbed doses and dose components. The relative effectiveness (RE), linking absorbed dose and detector response, has been calculated using amorphous track models. For the simulation, detailed models of

  11. Method and apparatus for dual-spaced fast/epithermal neutron porosity measurements

    International Nuclear Information System (INIS)

    Smith, H.D. Jr.

    1986-01-01

    A method is described for determining the porosity of earth formations in the vicinity of a well borehole, comprising: (a) irradiating the earth formations in the vicinity of the well borehole with a continuous chemical type source of fast neutrons, (b) detecting the fast neutron population at a first shorter spaced distance from the neutron source in the borehole and generating signals representative thereof, (c) detecting the epithermal neutron population at a second space distance from the neutron source in the borehole and generating signals representative thereof, the second spaced distance being greater than the first spaced distance from the neutron source, (d) forming a ratio of the signals representing the fast and epithermal neutron populations to derive a measurement signal functionally related to the porosity of the earth formations in the vicinity of the borehole, and (e) calibrating the measurement signal according to a predetermined functional relationship to derive a porosity signal quantitatively representative of the porosity of the earth formations in the vicinity of the borehole

  12. Combination of epithermal and inelastic neutron scattering methods to locate coal and oil-shale zones

    International Nuclear Information System (INIS)

    Schultz, W.E.

    1976-01-01

    A pulsed neutron generator of the deuterium-tritium reaction type irradiates earth formations in the vicinity of a borehole with 14 MeV neutrons. Gamma rays produced by the inelastic scattering of the fast neutrons are observed in four energy regions of the gamma ray energy spectrum corresponding to the inelastic scattering of neutrons by carbon, oxygen, silicon, and calcium. The carbon/oxygen, calcium/silicon, and carbon plus oxygen gamma rays are found and combined with a separately derived hydrogen index log to determine the quality of coal-bearing formations or oil-shale regions. The hydrogen index curve is found preferably by a dual-spaced detector epithermal neutron porosity logging technique or from a conventional thermal neutron gamma ray log

  13. Filtered epithermal quasi-monoenergetic neutron beams at research reactor facilities

    International Nuclear Information System (INIS)

    Mansy, M.S.; Bashter, I.I.; El-Mesiry, M.S.; Habib, N.; Adib, M.

    2015-01-01

    Filtered neutron techniques were applied to produce quasi-monoenergetic neutron beams in the energy range of 1.5–133 keV at research reactors. A simulation study was performed to characterize the filter components and transmitted beam lines. The filtered beams were characterized in terms of the optimal thickness of the main and additive components. The filtered neutron beams had high purity and intensity, with low contamination from the accompanying thermal emission, fast neutrons and γ-rays. A computer code named “QMNB” was developed in the “MATLAB” programming language to perform the required calculations. - Highlights: • Quasi-monoenergetic neutron beams in energy range from (1.5–133) keV. • Interference between the resonance and potential scattering amplitudes. • Epithermal neutron beams used in BNCT

  14. Epithermal neutron beam design for neutron capture therapy at the Power Burst Facility and the Brookhaven Medical Research Reactor

    International Nuclear Information System (INIS)

    Wheeler, F.J.; Parsons, D.K.; Rushton, B.L.; Nigg, D.W.

    1990-01-01

    Nuclear design studies have been performed for two reactor-based epithermal neutron beams for cancer treatment by neutron capture therapy (NCT). An intermediate-intensity epithermal beam has been designed and implemented at the Brookhaven Medical Research Reactor (BMRR). Measurements show that the BMRR design predictions for the principal characteristics of this beam are accurate. A canine program for research into the biological effects of NCT is now under way at BMRR. The design for a high-intensity epithermal beam with minimal contamination from undesirable radiation components has been finalized for the Power Burst Facility (PBF) at the Idaho National Engineering Laboratory. This design will be implemented when it is determined that human NCT trials are advisable. The PBF beam will exhibit approximately an order of magnitude improvement in absolute epithermal flux intensity over that available in the BMRR, and its angular distribution and spectral characteristics will be more advantageous for NCT. The combined effects of beam intensity, angular distribution, spectrum, and contaminant level allow the desired tumor radiation dose to be delivered in much shorter times than are possible with the currently available BMRR beam, with a significant reduction (factor of 3 to 5) in collateral dose due to beam contaminants

  15. Qualitative dose response of the normal canine head to epithermal neutron irradiation with and without boron capture

    International Nuclear Information System (INIS)

    DeHaan, C.E.; Gavin, P.R.; Kraft, S.L.; Wheeler, F.J.; Atkinson, C.A.

    1992-01-01

    Boron Neutron Capture Therapy is being re-evaluated for the treatment of intracranial tumors. Prior to human clinical trials, determination of normal tissue tolerance is critical. Dogs were chosen as a large animal model for the following reasons. Dogs can be evaluated with advanced imaging, diagnostic and therapeutic modalities. Dogs are amenable to detailed neurologic examination and subtle behavioral changes are easily detected. Specifically, Labrador retrievers were chosen for their large body and head size. The dogs received varying doses of epithermal neutron irradiation and boron neutron capture irradiation using an epithermal neutron source. The dogs were closely monitored for up to one year post irradiation

  16. Manual for the Epithermal Neutron Multiplicity Detector (ENMC) for Measurement of Impure MOX and Plutonium Samples

    International Nuclear Information System (INIS)

    Menlove, H. O.; Rael, C. D.; Kroncke, K. E.; DeAguero, K. J.

    2004-01-01

    We have designed a high-efficiency neutron detector for passive neutron coincidence and multiplicity counting of dirty scrap and bulk samples of plutonium. The counter will be used for the measurement of impure plutonium samples at the JNC MOX fabrication facility in Japan. The counter can also be used to create working standards from bulk process MOX. The detector uses advanced design "3He tubes to increase the efficiency and to shorten the neutron die-away time. The efficiency is 64% and the die-away time is 19.1 ?s. The Epithermal Neutron Multiplicity Counter (ENMC) is designed for high-precision measurements of bulk plutonium samples with diameters of less than 200 mm. The average neutron energy from the sample can be measured using the ratio of the inner ring of He-3 tubes to the outer ring. This report describes the hardware, performance, and calibration for the ENMC.

  17. Conceptual design of 30 MeV magnet system used for BNCT epithermal neutron source

    International Nuclear Information System (INIS)

    Slamet Santosa; Taufik

    2015-01-01

    Conceptual design of 30 MeV Magnet System Used for BNCT Epithermal Neutron Source has been done based on methods of empirical model of basic equation, experiences of 13 MeV cyclotron magnet design and personal communications. In the field of health, cyclotron can be used as an epithermal neutron source for Boron Neutron Capture Therapy (BNCT). The development of cyclotron producing epithermal neutrons for BNCT has been performed at Kyoto University, of which it produces a proton beam current of 1.1 mA with energy of 30 MeV. With some experiences on 13 MeV cyclotron magnet design, to support BNCT research and development we performed the design studies of 30 MeV cyclotron magnet system, which is one of the main components of the cyclotron for deflecting proton beam into circular trajectory and serves as beam focusing. Results of this study are expected to define the parameters of particular cyclotron magnet. The scope of this study includes the study of the parameters component of the 30 MeV cyclotron and magnet initial parameters. The empirical method of basic equation model is then corroborated by a simulation using Superfish software. Based on the results, a 30 MeV cyclotron magnet for BNCT neutron source enables to be realized with the parameters of B 0 = 1.06 T, frequency RF = 64.733938 ≈ 65 MHz, the external radius of 0.73 m, the radius of the polar = 0.85 m, BH = 1.95 T and a gap hill of 4 cm. Because proton beam current that be needed for BNCT application is very large, then in the calculation it is chosen a great focusing axial νz = 0.630361 which can generate B V = 0.44 T. (author)

  18. Metrology and quality of radiation therapy dosimetry of electron, photon and epithermal neutron beams

    Energy Technology Data Exchange (ETDEWEB)

    Kosunen, A

    1999-08-01

    In radiation therapy using electron and photon beams the dosimetry chain consists of several sequential phases starting by the realisation of the dose quantity in the Primary Standard Dosimetry Laboratory and ending to the calculation of the dose to a patient. A similar procedure can be described for the dosimetry of epithermal neutron beams in boron neutron capture therapy (BNCT). To achieve the required accuracy of the dose delivered to a patient the quality of all steps in the dosimetry procedure has to be considered. This work is focused on two items in the dosimetry chains: the determination of the dose in the reference conditions and the evaluation of the accuracy of dose calculation methods. The issues investigated and discussed in detail are: a)the calibration methods of plane parallel ionisation chambers used in electron beam dosimetry, (b) the specification of the critical dosimetric parameter i.e. the ratio of stopping powers for water to air, (S I ?){sup water} {sub air}, in photon beams, (c) the feasibility of the twin ionization chamber technique for dosimetry in epithermal neutron beams applied to BNCT and (d) the determination accuracy of the calculated dose distributions in phantoms in electron, photon, and epithermal neutron beams. The results demonstrate that up to a 3% improvement in the consistency of dose determinations in electron beams is achieved by the calibration of plane parallel ionisation chambers in high energy electron beams instead of calibrations in {sup 60}Co gamma beams. In photon beam dosimetry (S I ?){sup water} {sub air} can be determined with an accuracy of 0.2% using the percentage dose at the 10 cm depth, %dd(10), as a beam specifier. The use of %odd(10) requires the elimination of the electron contamination in the photon beam. By a twin ionisation chamber technique the gamma dose can be determined with uncertainty of 6% (1 standard deviation) and the total neutron dose with an uncertainty of 15 to 20% (1 standard deviation

  19. Metrology and quality of radiation therapy dosimetry of electron, photon and epithermal neutron beams

    International Nuclear Information System (INIS)

    Kosunen, A.

    1999-08-01

    In radiation therapy using electron and photon beams the dosimetry chain consists of several sequential phases starting by the realisation of the dose quantity in the Primary Standard Dosimetry Laboratory and ending to the calculation of the dose to a patient. A similar procedure can be described for the dosimetry of epithermal neutron beams in boron neutron capture therapy (BNCT). To achieve the required accuracy of the dose delivered to a patient the quality of all steps in the dosimetry procedure has to be considered. This work is focused on two items in the dosimetry chains: the determination of the dose in the reference conditions and the evaluation of the accuracy of dose calculation methods. The issues investigated and discussed in detail are: a)the calibration methods of plane parallel ionisation chambers used in electron beam dosimetry, (b) the specification of the critical dosimetric parameter i.e. the ratio of stopping powers for water to air, (S I ?) water air , in photon beams, (c) the feasibility of the twin ionization chamber technique for dosimetry in epithermal neutron beams applied to BNCT and (d) the determination accuracy of the calculated dose distributions in phantoms in electron, photon, and epithermal neutron beams. The results demonstrate that up to a 3% improvement in the consistency of dose determinations in electron beams is achieved by the calibration of plane parallel ionisation chambers in high energy electron beams instead of calibrations in 60 Co gamma beams. In photon beam dosimetry (S I ?) water air can be determined with an accuracy of 0.2% using the percentage dose at the 10 cm depth, %dd(10), as a beam specifier. The use of %odd(10) requires the elimination of the electron contamination in the photon beam. By a twin ionisation chamber technique the gamma dose can be determined with uncertainty of 6% (1 standard deviation) and the total neutron dose with an uncertainty of 15 to 20% (1 standard deviation). To improve the accuracy

  20. Physical parameters and biological effects of the LVR-15 epithermal neutron beam

    International Nuclear Information System (INIS)

    Burian, J.; Marek, M.; Rejchrt, J.; Viererbl, L.; Gambarini, G.; Mares, V.; Vanossi, E.; Judas, L.

    2006-01-01

    Monitoring of the physical and biological properties of the epithermal neutron beam constructed at the multipurpose LVR-15 nuclear reactor for NCT therapy of brain tumors showed that its physical and biological properties are stable in time and independent on an ad hoc reconfiguration of the reactor core before its therapeutic use. Physical parameters were monitored by measurement of the neutron spectrum, neutron profile, fast neutron kerma rate in tissue and photon absorbed dose, the gel dosimetry was used with the group of standard measurement methods. The RBE of the beam, as evaluated by 3 different biological models, including mouse intestine crypt regeneration assay, germinative zones of the immature rat brain and C6 glioma cells in culture, ranged from 1.70 to 1.99. (author)

  1. Reactor beam calculations to determine optimum delivery of epithermal neutrons for treatment of brain tumors

    International Nuclear Information System (INIS)

    Wheeler, F.J.; Nigg, D.W.; Capala, J.

    1997-01-01

    Studies were performed to assess theoretical tumor control probability (TCP) for brain-tumor treatment with boron neutron capture therapy (BNCT) using epithermal neutron sources from reactors. The existing epithermal-neutron beams at the Brookhaven Medical Research Reactor Facility (BMRR), the Petten High Flux Reactor Facility (HWR) and the Finnish Research Reactor 1 (FIR1) have been analyzed and characterized using common analytical and measurement methods allowing for this inter-comparison. Each of these three facilities is unique and each offers an advantage in some aspect of BNCT, but none of these existing facilities excel in all neutron-beam attributes as related to BNCT. A comparison is therefore also shown for a near-optimum reactor beam which does not currently exist but which would be feasible with existing technology. This hypothetical beam is designated BNCT-1 and has a spectrum similar to the FIR-1, the mono-directionality of the HFR and the intensity of the BMRR. A beam very similar to the BNCT-1 could perhaps be achieved with modification of the BMRR, HFR, or FIR, and could certainly be realized in a new facility with today's technology

  2. An in-situ check of the epithermal neutron log calibration

    International Nuclear Information System (INIS)

    Burkhard, N.R.

    1993-01-01

    The epithermal neutron log is used to measure the water content of the formation. The large hole epithermal neutron sonde (ENS) utilized at the Nevada Test Site (NTS) has been calibrated in the Hydrogen Content Test Facility (HCTF). These calibrations are used to correct the measured neutron count rate for the effects of tool stand-off and density. For some time, the suspicion has existed that the water contents that are calculated from the ENS data are too large. Hole U2gj represented a unique opportunity to check the validity of the ENS calibration under realistic logging conditions; a portion of the hole had been cemented and redrilled and then logged. The cements have a known water content and can be used as an in-situ calibration check. The author found that the water contents from the log data after processing with the existing calibrations are consistent with these known cement water contents. In addition, the study indicates that the raw neutron data might be more appropriately smoothed by using a median smoother rather than the currently utilized mean smoother

  3. An in-situ check of the epithermal neutron log calibration

    International Nuclear Information System (INIS)

    Burkhard, N.R.

    1993-09-01

    The epithermal neutron log is used to measure the water content of the formation. The large hole epithermal neutron sonde (ENS) that we utilize at the Nevada Test Site (NTS) has been calibrated in the Hydrogen Content Test Facility (HCTF). These calibrations are used to correct the measured neutron count rate for the effects of tool stand-off and density. For sometime, the suspicion has existed that the water contents that are calculated from the ENS data are too large. Hole U2gj represented a unique opportunity to check the validity of the ENS calibration under realistic logging conditions; a portion of the hole had been cemented and re drilled and then logged. The cements have a known water content and can be used as an in situ calibration check. I found that the water contents from the log data after processing with the existing calibrations are consistent with these known cement water contents. In addition, the study indicates that the raw neutron data might be more appropriately smoothed by using a median smoother rather than the currently utilized mean smoother

  4. Boron neutron capture therapy (BNCT) for glioblastoma multiforme using the epithermal neutron beam at the Brookhaven Medical Research Reactor

    International Nuclear Information System (INIS)

    Capala, J.; Diaz, A.Z.; Chadha, M.

    1997-01-01

    The abstract describes evaluation of boron neutron capture therapy (BNCT) for two groups of glioblastoma multiforme patients. From September 1994 to February 1996 15 patients have been treated. In September 1997 another 34 patients were examined. Authors determined a safe starting dose for BNCT using epithermal neutrons and BPA-F. They have also evaluated adverse effects of BNCT at this starting dose. Therapeutic effectiveness of this starting dose has been evaluated. No significant side effects from BPA-F infusion or BNCT treatment were observed in normal brains

  5. Boron neutron capture therapy (BNCT) for glioblastoma multiforme using the epithermal neutron beam at the Brookhaven Medical Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Capala, J. [Brookhaven National Lab., Upton, NY (United States); Diaz, A.Z.; Chadha, M. [Univ. Hospital, State Univ. of New York, NY (United States)] [and others

    1997-12-31

    The abstract describes evaluation of boron neutron capture therapy (BNCT) for two groups of glioblastoma multiforme patients. From September 1994 to February 1996 15 patients have been treated. In September 1997 another 34 patients were examined. Authors determined a safe starting dose for BNCT using epithermal neutrons and BPA-F. They have also evaluated adverse effects of BNCT at this starting dose. Therapeutic effectiveness of this starting dose has been evaluated. No significant side effects from BPA-F infusion or BNCT treatment were observed in normal brains.

  6. Photon detectors for epithermal neutron scattering at high-ω and low-q

    International Nuclear Information System (INIS)

    Pietropaolo, A.; Senesi, R.; Tardocchi, M.; Andreani, C.; Gorini, G.

    2004-01-01

    Inelastic epithermal neutron scattering at high energy (ℎω≥1 eV) and low wave vector (q≤10 A -1 ) transfers is the unique technique for the investigation of high-energy excitations in a variety of systems, ranging from magnetic materials to semiconductors. The key issue in order to make these measurements feasible on inverse geometry spectrometers, is to develop suitable detection systems for neutrons in the energy range 1-100 eV. The Resonance Detector Spectrometer configuration has to be considered as the most promising approach for electron Volt neutron spectroscopy. This configuration will be employed in the new low angle detector bank, VLAD, planned for VESUVIO spectrometer operating at ISIS source

  7. Fission reactor based epithermal neutron irradiation facilities for routine clinical application in BNCT-Hatanaka memorial lecture

    International Nuclear Information System (INIS)

    Harling, Otto K.

    2009-01-01

    Based on experience gained in the recent clinical studies at MIT/Harvard, the desirable characteristics of epithermal neutron irradiation facilities for eventual routine clinical BNCT are suggested. A discussion of two approaches to using fission reactors for epithermal neutron BNCT is provided. This is followed by specific suggestions for the performance and features needed for high throughput clinical BNCT. An example of a current state-of-the-art, reactor based facility, suited for routine clinical use is discussed. Some comments are provided on the current status of reactor versus accelerator based epithermal neutron sources for BNCT. This paper concludes with a summary and a few personal observations on BNCT by the author.

  8. Thermal and epithermal neutrons in the treatment of neoplasms

    International Nuclear Information System (INIS)

    Sweet, W.H.; Wellum, G.; Tolpin, E.; Messer, J.R.

    1975-01-01

    Progress is reported in the preparation and testing of boron compounds for use as targets in the neutron capture therapy of neoplasms. The synthesis and structural confirmation of the disulfide, B 1 H 11 SSB 12 H 11 -4 is reported as well as a new structural model for its mono-oxidized derivative, B 12 H 11 SOSB 12 H 11 -4 , which showed useful tumor:blood concentration ratios in rats after three I. V. injections. The material, B 12 H 11 (SH) 2 -2 , was isolated and identified from impure Cs 2 B 12 H 11 SH. The former anion was shown to be responsible, in its oxidized form, for the excellent tumor uptake results shown by impure B 12 H 11 SH -2 in the past. As a consequence of this work, a borane polymer was synthesized which has shown extremely encouraging tumor uptake properties. The synthesis of this polymer depended on our production and characterization of the first stable thiyl radical at room temperature, B 12 H 11 -S: -2 . The retesting of certain phosphate boranes is reported. And a reagent, namely acetyl sulfenyl chloride, lSCOCH 3 , has been found which will produce B 12 H 11 SH -2 in a laboratory synthesis. The ability of sulfur derivatives of B 12 H 11 SH -2 to bind to proteins was examined, as was the blood distribution of two of these interesting boranes. The amount of non-protein bound borane was related to the rate of blood clearance of the borane in rats. Progress is also reported on dog irradiation experiments. (U.S.)

  9. OPTIMIZATION OF THE EPITHERMAL NEUTRON BEAM FOR BORON NEUTRON CAPTURE THERAPY AT THE BROOKHAVEN MEDICAL RESEARCH REACTOR.

    Energy Technology Data Exchange (ETDEWEB)

    HU,J.P.; RORER,D.C.; RECINIELLO,R.N.; HOLDEN,N.E.

    2002-08-18

    Clinical trials of Boron Neutron Capture Therapy for patients with malignant brain tumor had been carried out for half a decade, using an epithermal neutron beam at the Brookhaven's Medical Reactor. The decision to permanently close this reactor in 2000 cut short the efforts to implement a new conceptual design to optimize this beam in preparation for use with possible new protocols. Details of the conceptual design to produce a higher intensity, more forward-directed neutron beam with less contamination from gamma rays, fast and thermal neutrons are presented here for their potential applicability to other reactor facilities. Monte Carlo calculations were used to predict the flux and absorbed dose produced by the proposed design. The results were benchmarked by the dose rate and flux measurements taken at the facility then in use.

  10. The Measurement of Epithermal-to-Thermal U-238 Neutron Capture Rate (ρ28) in Aagesta Power Reactor Fuel

    International Nuclear Information System (INIS)

    Bernander, G.

    1967-09-01

    The epithermal-to-thermal neutron capture rate ratio ρ 28 in U-238 in Aagesta fuel has been measured by the chemical separation method. The method involves the isolation of Np-239 from uranium and fission products by reversed phase partition chromatography. Although somewhat elaborate, and in spite of difficulties with residual fission products, the method has yielded reasonably accurate results. Further development work on chemical procedures may lead to some improvement. A comparison with the coincidence method - electronic separation of activities - has not shown any large systematic differences between the two methods. The separation of the epithermal U-235 activation from the total has been achieved by means of the '1/v subtraction technique' using copper foils as the 1/v monitor. The complementary thermal column irradiations required have been performed in the research reactors TRIGA (Helsinki) and R1 (Stockholm). From the measured ρ 28 values the resonance escape probability (p) and the initial conversion ratio (ICR) may be calculated using cross-section data and other lattice parameters. Comparisons with theoretical values of ρ and ICR as calculated with the BURNUP lattice parameter code are favourable

  11. The Measurement of Epithermal-to-Thermal U-238 Neutron Capture Rate in Aagesta Power Reactor Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Bernander, G

    1967-09-15

    The epithermal-to-thermal neutron capture rate ratio {rho}{sub 28} in U-238 in Aagesta fuel has been measured by the chemical separation method. The method involves the isolation of Np-239 from uranium and fission products by reversed phase partition chromatography. Although somewhat elaborate, and in spite of difficulties with residual fission products, the method has yielded reasonably accurate results. Further development work on chemical procedures may lead to some improvement. A comparison with the coincidence method - electronic separation of activities - has not shown any large systematic differences between the two methods. The separation of the epithermal U-235 activation from the total has been achieved by means of the '1/v subtraction technique' using copper foils as the 1/v monitor. The complementary thermal column irradiations required have been performed in the research reactors TRIGA (Helsinki) and R1 (Stockholm). From the measured {rho}{sub 28} values the resonance escape probability (p) and the initial conversion ratio (ICR) may be calculated using cross-section data and other lattice parameters. Comparisons with theoretical values of {rho} and ICR as calculated with the BURNUP lattice parameter code are favourable.

  12. The alanine detector in BNCT dosimetry: dose response in thermal and epithermal neutron fields.

    Science.gov (United States)

    Schmitz, T; Bassler, N; Blaickner, M; Ziegner, M; Hsiao, M C; Liu, Y H; Koivunoro, H; Auterinen, I; Serén, T; Kotiluoto, P; Palmans, H; Sharpe, P; Langguth, P; Hampel, G

    2015-01-01

    The response of alanine solid state dosimeters to ionizing radiation strongly depends on particle type and energy. Due to nuclear interactions, neutron fields usually also consist of secondary particles such as photons and protons of diverse energies. Various experiments have been carried out in three different neutron beams to explore the alanine dose response behavior and to validate model predictions. Additionally, application in medical neutron fields for boron neutron capture therapy is discussed. Alanine detectors have been irradiated in the thermal neutron field of the research reactor TRIGA Mainz, Germany, in five experimental conditions, generating different secondary particle spectra. Further irradiations have been made in the epithermal neutron beams at the research reactors FiR 1 in Helsinki, Finland, and Tsing Hua open pool reactor in HsinChu, Taiwan ROC. Readout has been performed with electron spin resonance spectrometry with reference to an absorbed dose standard in a (60)Co gamma ray beam. Absorbed doses and dose components have been calculated using the Monte Carlo codes fluka and mcnp. The relative effectiveness (RE), linking absorbed dose and detector response, has been calculated using the Hansen & Olsen alanine response model. The measured dose response of the alanine detector in the different experiments has been evaluated and compared to model predictions. Therefore, a relative effectiveness has been calculated for each dose component, accounting for its dependence on particle type and energy. Agreement within 5% between model and measurement has been achieved for most irradiated detectors. Significant differences have been observed in response behavior between thermal and epithermal neutron fields, especially regarding dose composition and depth dose curves. The calculated dose components could be verified with the experimental results in the different primary and secondary particle fields. The alanine detector can be used without

  13. Radiobiology studies for the evaluation of epithermal neutron beams used for BNCT

    International Nuclear Information System (INIS)

    Green, S.; Jones, B.; Mill, A.J.

    2006-01-01

    This paper outlines our plans for a study to establish the radiobiological effectiveness of the various mixes of radiation components present in an epithermal neutron beam designed for BNCT and to incorporate these data into clinical protocols for the treatment of malignant glioma. This is a description of work which is funded and just now beginning in Birmingham so no results can be presented. Our project will involve a combination of experimental measurements carried out in Birmingham and in Boston and mathematical modelling carried out in Birmingham. Despite all the extant in-vitro and in-vivo work, there is no widely accepted method to determine biological effect by accounting for variations in beam component mix, dose rate and treatment fractionation for disparate from the various BNCT centres. The objectives of this study are: To develop a cell-based radiobiology protocol to provide essential data on safety and efficacy of beams for Boron Neutron Capture Therapy (BNCT) in advance of clinical trials. To exploit the facilities at Massachusetts Institute of Technology for variable dose-rate epithermal irradiations to validate the above protocol. To develop mathematical models of this radiobiological system that can be used to inform decisions on dose selection, fractionation schedules, BNCT use as supplementary boosts or for re-treatment of recurrent cancers. To provide fundamental data relevant to the understanding of the radiobiology of simultaneous mixed high-and low-LET radiations over a clinically relevant dose-range. (author)

  14. Measurement of the epithermal neutron flux of the Argonauta reactor by the Sandwich method

    International Nuclear Information System (INIS)

    Nascimento, H.M.

    1973-01-01

    A common method of obtaining information about the neutron spectrum in the energy range of 1 eV to a few keV is by using resonance sandwich detectors. A sandwich detector is usually made up of three foils placed one on top of the other, each having the same thickness and being made of the same material which has a pronounced absorption resonance. To make an adequate evaluation, the sandwich method was compared with one using an isolated detector. The results obtained from approximate theoretical calculations were checked experimentally, using In, Au and Mn foils, in an isotropic 1/E flux in the Argonaut Reactor at I.E.N. As practical application of this method, the deviation from a 1/E spectrum of the epithermal neutron flux in the core and external graphite reflector of the Argonaut Reactor has been measured with the sandwich foils previously calibrated in a 1/E spectrum. (author)

  15. SPLET - A program for calculating the space-lethargy distribution of epithermal neutrons in a reactor lattice cell

    International Nuclear Information System (INIS)

    Matausek, M.V.; Zmijatevic, I.

    1981-01-01

    A procedure to solve the space-single-lethargy dependent transport equation for epithermal neutrons in a cylindricised multi-region reactor lattice cell has been developed and proposed in the earlier papers. Here, the computational algorithm is comprised and the computing program SPLET, which calculates the space-lethargy distribution of the spherical harmonics neutron flux moments, as well as the related integral quantities as reaction rates and resonance integrals, is described. (author)

  16. Multipurpose epithermal neutron beam on new research station at MARIA research reactor in Swierk-Poland

    Energy Technology Data Exchange (ETDEWEB)

    Gryzinski, M.A.; Maciak, M. [National Centre for Nuclear Research, Andrzeja Soltana 7, 05-400 Otwock-Swierk (Poland)

    2015-07-01

    MARIA reactor is an open-pool research reactor what gives the chance to install uranium fission converter on the periphery of the core. It could be installed far enough not to induce reactivity of the core but close enough to produce high flux of fast neutrons. Special design of the converter is now under construction. It is planned to set the research stand based on such uranium converter in the near future: in 2015 MARIA reactor infrastructure should be ready (preparation started in 2013), in 2016 the neutron beam starts and in 2017 opening the stand for material and biological research or for medical training concerning BNCT. Unused for many years, horizontal channel number H2 at MARIA research rector in Poland, is going to be prepared as a part of unique stand. The characteristics of the neutron beam will be significant advantage of the facility. High flux of neutrons at the level of 2x10{sup 9} cm{sup -2}s{sup -1} will be obtainable by uranium neutron converter located 90 cm far from the reactor core fuel elements (still inside reactor core basket between so called core reflectors). Due to reaction of core neutrons with converter U{sub 3}Si{sub 2} material it will produce high flux of fast neutrons. After conversion neutrons will be collimated and moderated in the channel by special set of filters and moderators. At the end of H2 channel i.e. at the entrance to the research room neutron energy will be in the epithermal energy range with neutron intensity at least at the level required for BNCT (2x10{sup 9} cm{sup -2}s{sup -1}). For other purposes density of the neutron flux could be smaller. The possibility to change type and amount of installed filters/moderators which enables getting different properties of the beam (neutron energy spectrum, neutron-gamma ratio and beam profile and shape) is taken into account. H2 channel is located in separate room which is adjacent to two other empty rooms under the preparation for research laboratories (200 m2). It is

  17. Development of new instrumentation for epithermal neutron scattering at very low angles

    International Nuclear Information System (INIS)

    Tardocchi, M.; Pietropaolo, A.; Andreani, C.; Gorini, G.; Perelli-Cippo, E.; Rhodes, N.J.; Schooneveld, E.M.; Senesi, R.

    2004-01-01

    New perspectives for epithermal neutron spectroscopy are opened up by the recent developments of Resonance Detectors (RD) for inverse geometry time-of-flight spectrometers at pulsed neutron sources. The RD is based on the combination of an analyser foil used as neutron-to-gamma converter and a suitable photon detector. Here, we report on the state of the RD which is based on a YAP scintillator viewing a natural uranium analyser foil. The response of the YAP detector to the radiative capture γ emission from the uranium analyser foil has been characterized with a bi-parametric measurement of a reference Pb sample, which allowed simultaneous measurements of both neutron time-of-flight and γ pulse height (energy) spectra. The analysis of the γ pulse height and neutron time-of-flight spectra permitted to identify the signal and background components. These measurements showed that a significant improvement in the signal-to-background ratio can be achieved by setting a lower level discrimination on the photon energy at about 600keV. The first application of RD is the Very Low Angle Detector Bank (VLAD) which is planned to be installed in the next three years as an upgrade of the VESUVIO spectrometer, at the ISIS pulsed neutron source. VLAD will extend the (q,ω) kinematical to low wave vector transfers (q10A-1) coupled to high-energy transfers (-bar ω>1eV), which is still unexplored by neutron scattering experiments. The first measurements obtained on an ice sample with a VLAD prototype consisting of four RD units are presented here

  18. Development of new instrumentation for epithermal neutron scattering at very low angles

    Energy Technology Data Exchange (ETDEWEB)

    Tardocchi, M. [INFM, UdR Milano-Bicocca and Dipartimento di Fisica ' G.Occhialini' , Universita degli Studi di Milano-Bicocca, Pizza Della Scienza 3, Milan 20126 (Italy)]. E-mail: marco.tardocchi@mib.infn.it; Pietropaolo, A. [Dipartimento di Fisica, Universita degli Studi di Roma Tor Vergata and INFM, UdR Roma Tor Vergata, Rome (Italy); Andreani, C. [Dipartimento di Fisica, Universita degli Studi di Roma Tor Vergata and INFM, UdR Roma Tor Vergata, Rome (Italy); Gorini, G. [INFM, UdR Milano-Bicocca and Dipartimento di Fisica ' G.Occhialini' , Universita degli Studi di Milano-Bicocca, Pizza Della Scienza 3, Milan 20126 (Italy); Perelli-Cippo, E. [INFM, UdR Milano-Bicocca and Dipartimento di Fisica ' G.Occhialini' , Universita degli Studi di Milano-Bicocca, Pizza Della Scienza 3, Milan 20126 (Italy); Rhodes, N.J. [Isis Facility, Rutherford Appleton Laboratory, Chilton, Didcot (United Kingdom); Schooneveld, E.M. [Isis Facility, Rutherford Appleton Laboratory, Chilton, Didcot (United Kingdom); Senesi, R. [Dipartimento di Fisica, Universita degli Studi di Roma Tor Vergata and INFM, UdR Roma Tor Vergata, Rome (Italy)

    2004-12-11

    New perspectives for epithermal neutron spectroscopy are opened up by the recent developments of Resonance Detectors (RD) for inverse geometry time-of-flight spectrometers at pulsed neutron sources. The RD is based on the combination of an analyser foil used as neutron-to-gamma converter and a suitable photon detector. Here, we report on the state of the RD which is based on a YAP scintillator viewing a natural uranium analyser foil. The response of the YAP detector to the radiative capture {gamma} emission from the uranium analyser foil has been characterized with a bi-parametric measurement of a reference Pb sample, which allowed simultaneous measurements of both neutron time-of-flight and {gamma} pulse height (energy) spectra. The analysis of the {gamma} pulse height and neutron time-of-flight spectra permitted to identify the signal and background components. These measurements showed that a significant improvement in the signal-to-background ratio can be achieved by setting a lower level discrimination on the photon energy at about 600keV. The first application of RD is the Very Low Angle Detector Bank (VLAD) which is planned to be installed in the next three years as an upgrade of the VESUVIO spectrometer, at the ISIS pulsed neutron source. VLAD will extend the (q,{omega}) kinematical to low wave vector transfers (q10A-1) coupled to high-energy transfers (-bar {omega}>1eV), which is still unexplored by neutron scattering experiments. The first measurements obtained on an ice sample with a VLAD prototype consisting of four RD units are presented here.

  19. Effective dose evaluation for BNCT treatment in the epithermal neutron beam at THOR

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.N. [Department of Engineering and System Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan (China)] [Division of Health Physics, Institute of Nuclear Energy Research, No. 1000, Wenhua Rd., Jiaan Village, Longtan Township, Taoyuan County 32546, Taiwan (China); Huang, C.K. [Institute of Nuclear Engineering and Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan (China); Tsai, W.C. [Department of Engineering and System Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan (China); Liu, Y.H. [Nuclear Science and Technol. Develop. Center, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan (China); Jiang, S.H., E-mail: shjiang@mx.nthu.edu.tw [Department of Engineering and System Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan (China)] [Institute of Nuclear Engineering and Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan (China)

    2011-12-15

    This paper aims to evaluate the effective dose as well as equivalent doses of several organs of an adult hermaphrodite mathematical phantom according to the definition of ICRP Publication 60 for BNCT treatments of brain tumors in the epithermal neutron beam at THOR. The MCNP5 Monte Carlo code was used for the calculation of the average absorbed dose of each organ. The effective doses for a typical brain tumor treatment with a tumor treatment dose of 20 Gy-eq were evaluated to be 0.59 and 0.35 Sv for the LLAT and TOP irradiation geometries, respectively. In addition to the stochastic effect, it was found that it is also likely to produce deterministic effects, such as cataracts and depression of haematopoiesis.

  20. An epithermal neutron source for BNCT based on an ESQ-accelerator

    International Nuclear Information System (INIS)

    Ludewigt, B.A.; Chu, W.T.; Donahue, R.J.; Kwan, J.; Phillips, T.L.; Reginato, L.L.; Wells, R.P.

    1997-07-01

    An accelerator-based BNCT facility is under development at the Lawrence Berkeley National Laboratory. Neutrons will be produced via the 7 Li(p,n) reaction at proton energies of about 2.5 MeV with subsequent moderation and filtering for shaping epithermal neutron beams for BNCT. Moderator, filter, and shielding assemblies have been modeled using MCNP. Head-phantom dose distributions have been calculated using the treatment planning software BNCT RTPE. The simulation studies have shown that a proton beam current of ∼ 20 mA is required to deliver high quality brain treatments in about 40 minutes. The results also indicate that significantly higher doses can be delivered to deep-seated tumors in comparison to the Brookhaven Medical Research Reactor beam. An electrostatic quadrupole (ESQ) accelerator is ideally suited to provide the high beam currents desired. A novel power supply utilizing the air-coupled transformer concept is under development. It will enable the ESQ-accelerator to deliver proton beam currents exceeding 50 mA. A lithium target has been designed which consists of a thin layer of lithium on an aluminum backing. Closely spaced, narrow coolant passages cut into the aluminum allow the removal of a 50kW heat-load by convective water cooling. The system under development is suitable for hospital installation and has the potential for providing neutron beams superior to reactor sources

  1. The orientation effect in the activities of neutronic probes

    International Nuclear Information System (INIS)

    Vigon, M. A.

    1956-01-01

    The formulae relating activity and position of a neutron irradiated Indium foil, have been verified experimentally. Measurements with both thin and thick foils for epithermal neutrons and with thick foils for thermal neutrons have been carried out. The experimental results agree qualitatively with the theoretical predictions. (Author)

  2. Development of the Very Low Angle Detector (VLAD) for detection of epithermal neutrons at low momentum transfers

    International Nuclear Information System (INIS)

    Tardocchi, M.; Andreani, C.; Cremonesi, O.; Gorini, G.; Perelli-Cippo, E.; Pietropaolo, A.; Rhodes, N.; Schooneveld, E.; Senesi, R.

    2006-01-01

    New perspectives for epithermal neutron spectroscopy are opened up by the recent development of new instrumentation for inverse geometry time of flight spectrometers at pulsed neutron sources. One example is the Very Low Angle Detector (VLAD) bank which will be installed as an upgrade of the VESUVIO neutron spectrometer, at the ISIS pulsed neutron source. VLAD is developed for detecting epithermal neutrons in the 1-100 eV energy range at very low scattering angles (l deg. - 5 deg.). VLAD will extend the kinematical region covered by today's neutron scattering experiments to the region of low wave vector transfers ( -1 ) and high energy transfers (>1 eV). Accessing such kinematical region will allow new experimental studies in condensed matter systems. The neutron detection is based on Resonance Detectors (RD), which consist of the combination of a resonance foil used as neutron-to-gamma converter and a photon detector. The results obtained with a prototype VLAD detector confirm the potential of this kind of experiments at scattering angles as low as 2 deg. - 5 deg. GEANT4 simulations are used to address issues, such as detector cross talk, which arise with the construction of compact RD arrays

  3. Comparison between different flux traps assembled in the core of the nuclear reactor IPEN/MB-01 by measuring of the thermal and epithermal neutron fluxes using activation foils

    International Nuclear Information System (INIS)

    Mura, Luiz Ernesto Credidio; Bitelli, Ulysses d'Utra; Mura, Luis Felipe Liambos; Carluccio, Thiago; Andrade, Graciete Simoes de

    2011-01-01

    The production of radioisotopes is one of the most important applications of nuclear research reactors. This study investigated a method called Flux Trap, which is used to increase the yield of production of radioisotopes in nuclear reactors. The method consists in the rearrangement of the fuel rods to allow the increase of the thermal neutron flux in the irradiation region inside the reactor core, without changing the standard reactor power level. Various configurations were assembled with the objective of finding the configuration with the highest thermal neutron flux in the region of irradiation. The method of activation analysis was used to measure the thermal neutron flux and determine the most efficient reactor core configuration . It was found that there was an increase in the thermal neutron flux of 337% in the most efficient configuration, which demonstrates the effectiveness of the method. (author)

  4. Depth-dose evaluation for lung and pancreas cancer treatment by BNCT using an epithermal neutron beam

    International Nuclear Information System (INIS)

    Matsumoto, Tetsuo; Fukushima, Yuji

    2000-01-01

    The depth-dose distributions were evaluated for possible treatment of both lung and pancreas cancers using an epithermal neutron beam. The MCNP calculations showed that physical dose in tumors were 6 and 7 Gy/h, respectively, for lung and pancreas, attaining an epithermal neutron flux of 5x10 8 ncm -2 s -1 . The boron concentrations were assumed at 100 ppm and 30 ppm, respectively, for lung and pancreas tumors and normal tissues contains 1/10 tumor concentrations. The dose ratios of tumor to normal tissue were 2.5 and 2.4, respectively, for lung and pancreas. The dose evaluation suggests that BNCT could be applied for both lung and pancreas cancer treatment. (author)

  5. Improved Dose Targeting for a Clinical Epithermal Neutron Capture Beam Using Optional 6Li Filtration

    International Nuclear Information System (INIS)

    Binns, Peter J.; Riley, Kent J.; Ostrovsky, Yakov; Gao Wei; Albritton, J. Raymond; Kiger, W.S.; Harling, Otto K.

    2007-01-01

    Purpose: The aim of this study was to construct a 6 Li filter and to improve penetration of thermal neutrons produced by the fission converter-based epithermal neutron beam (FCB) for brain irradiation during boron neutron capture therapy (BNCT). Methods and Materials: Design of the 6 Li filter was evaluated using Monte Carlo simulations of the existing beam line and radiation transport through an ellipsoidal water phantom. Changes in beam performance were determined using three figures of merit: (1) advantage depth (AD), the depth at which the total biologically weighted dose to tumor equals the maximum weighted dose to normal tissue; (2) advantage ratio (AR), the ratio of the integral tumor dose to that of normal tissue averaged from the surface to the AD; and (3) advantage depth dose rate (ADDR), the therapeutic dose rate at the AD. Dosimetry performed with the new filter installed provided calibration data for treatment planning. Past treatment plans were recalculated to illustrate the clinical potential of the filter. Results: The 8-mm-thick Li filter is more effective for smaller field sizes, increasing the AD from 9.3 to 9.9 cm, leaving the AR unchanged at 5.7 but decreasing the ADDR from 114 to 55 cGy min -1 for the 12 cm diameter aperture. Using the filter increases the minimum deliverable dose to deep seated tumors by up to 9% for the same maximum dose to normal tissue. Conclusions: Optional 6 Li filtration provides an incremental improvement in clinical beam performance of the FCB that could help to establish a therapeutic window in the future treatment of deep-seated tumors

  6. A preliminary inter-centre comparison study for photon, thermal neutron and epithermal neutron responses of two pairs of ionisation chambers used for BNCT

    International Nuclear Information System (INIS)

    Roca, Antoaneta; Liu, Yuan-Hao; Wojnecki, Cecile; Green, Stuart; Nievaart, Sander; Ghani, Zamir; Moss, Ray

    2009-01-01

    The dual ionisation chamber technique is the recommended method for mixed field dosimetry of epithermal neutron beams. This paper presents initial data from an ongoing inter-comparison study involving two identical pairs of ionisation chambers used at the BNCT facilities of Petten, NL and of University of Birmingham, UK. The goal of this study is to evaluate the photon, thermal neutron and epithermal neutron responses of both pairs of TE(TE) (Exradin T2 type) and Mg(Ar) (Exradin M2 type) ionisation chambers in similar experimental conditions. At this stage, the work has been completed for the M2 type chambers and is intended to be completed for the T2 type chambers in the near future.

  7. Accelerator-based epithermal neutron sources for boron neutron capture therapy of brain tumors.

    Science.gov (United States)

    Blue, Thomas E; Yanch, Jacquelyn C

    2003-01-01

    This paper reviews the development of low-energy light ion accelerator-based neutron sources (ABNSs) for the treatment of brain tumors through an intact scalp and skull using boron neutron capture therapy (BNCT). A major advantage of an ABNS for BNCT over reactor-based neutron sources is the potential for siting within a hospital. Consequently, light-ion accelerators that are injectors to larger machines in high-energy physics facilities are not considered. An ABNS for BNCT is composed of: (1) the accelerator hardware for producing a high current charged particle beam, (2) an appropriate neutron-producing target and target heat removal system (HRS), and (3) a moderator/reflector assembly to render the flux energy spectrum of neutrons produced in the target suitable for patient irradiation. As a consequence of the efforts of researchers throughout the world, progress has been made on the design, manufacture, and testing of these three major components. Although an ABNS facility has not yet been built that has optimally assembled these three components, the feasibility of clinically useful ABNSs has been clearly established. Both electrostatic and radio frequency linear accelerators of reasonable cost (approximately 1.5 M dollars) appear to be capable of producing charged particle beams, with combinations of accelerated particle energy (a few MeV) and beam currents (approximately 10 mA) that are suitable for a hospital-based ABNS for BNCT. The specific accelerator performance requirements depend upon the charged particle reaction by which neutrons are produced in the target and the clinical requirements for neutron field quality and intensity. The accelerator performance requirements are more demanding for beryllium than for lithium as a target. However, beryllium targets are more easily cooled. The accelerator performance requirements are also more demanding for greater neutron field quality and intensity. Target HRSs that are based on submerged-jet impingement and

  8. Application of semiconductor MOSFET and pin diode dosimeters to epithermal neutron beam dose distribution measurements in phantoms

    International Nuclear Information System (INIS)

    Carolan, M.G.; Wallace, S.A.; Allen, B.J.; Rosenfeld, A.B.; Mathur, J.N.

    1996-01-01

    For any clinical application of Boron Neutron Capture Therapy (BNCT) fast and accurate dose calculations will be required for treatment planning. Such calculations are also necessary for the planning and interpretation of results from pre-clinical and clinical trials where the speed of calculation is not so critical. A dose calculation system based on the MCNP Monte Carlo Neutron transport code has been developed by Wallace. This system takes image data from CT scans and constructs a voxel based geometrical model for input into MCNP. To validate the calculations, a number of phantoms were constructed and exposed in the HB11 epithermal neutron beam at the HFR of the CEC Joint Research Centre in Petten. The doses recorded by arrays of PIN diode neutron dosimeters and MOSFET gamma dosimeters in these phantoms were compared with the calculated results from the MCNP dose planning system. Initial results have been reported elsewhere. Poster 197. (author)

  9. Comparison of Cadmium-Zinc-Telluride semiconductor and Yttrium-Aluminum-Perovskite scintillator as photon detectors for epithermal neutron spectroscopy

    International Nuclear Information System (INIS)

    Tardocchi, M.; Pietropaolo, A.; Andreani, C.; Gorini, G.; Imberti, S.; Perelli-Cippo, E.; Senesi, R.; Rhodes, N.; Schooneveld, E.M.

    2006-01-01

    The range of applications of epithermal neutron scattering experiments has been recently extended by the development of the Resonance Detector. In a Resonance Detector, resonant neutron absorption in an analyzer foil results in prompt emission of X- and γ-rays which are detected by a photon counter. Several combinations of analyzer foils and photon detectors have been studied and tested over the years and best results have been obtained with the combination of a natural uranium and (i) Cadmium-Zinc-Telluride (CZT) semiconductor (ii) Yttrium-Aluminum-Perovskite (YAP) scintillators. Here we compare the performance of the CZT semiconductor and YAP scintillator as Resonance Detector units. Two Resonance Detector prototypes made of natural uranium foil viewed by CZT and YAP were tested on the VESUVIO spectrometer at the ISIS spallation neutron source. The results show that both YAP and CZT can be used to detect epithermal neutrons in the energy range from 1 up to 66 eV. It was found that the signal-to-background ratio of the measurement can significantly be improved by raising the lower level discrimination threshold on the γ energy to about 600 keV. The advantages/disadvantages of the choice of a Resonance Detector based on YAP or CZT are discussed together with some potential applications

  10. Intraoperative boron neutron capture therapy for malignant gliomas. First clinical results of Tsukuba phase I/II trial using JAERI mixed thermal-epithermal beam

    International Nuclear Information System (INIS)

    Matsumura, A.; Yamamoto, T.; Shibata, Y.

    2000-01-01

    Since October 1999, a clinical trial of intraoperative boron neutron capture therapy (IOBNCT) is in progress at JRR-4 (Japan Research Reactor-4) in Japan Atomic Energy Research Institute (JAERI) using mixed thermal-epithermal beam (thermal neutron beam I: TNB-I). Compared to pure thermal beam (thermal neutron beam II: TNB-II), TNB-I has an improved neutron delivery into the deep region than TNB-II. The clinical protocol and the preliminary results will be discussed. (author)

  11. Characterisation of the TAPIRO BNCT epithermal facility

    Energy Technology Data Exchange (ETDEWEB)

    Burn, K. W. [FIS-NUC, ENEA, Via Martiri di Montesole 4, Bologna (Italy); Colli, V. [Dept. of Physics of Univ., INFN, Via Celoria 16, I-20133 Milano (Italy); Curzio, G.; D' Errico, F. [DIMNP, Univ. of Pisa, Via Diotisalvi 2, I-56126 Pisa (Italy); Gambarini, G. [Dept. of Physics of Univ., INFN, Via Celoria 16, I-20133 Milano (Italy); Rosi, G. [FIS-ION, ENEA, Casaccia, Via Anguillarese 301, I-00060 Santa Maria di Galeria, Roma (Italy); Scolari, L. [Dept. of Physics of Univ., INFN, Via Celoria 16, I-20133 Milano (Italy)

    2004-07-01

    A collimated epithermal beam for boron neutron capture therapy (BNCT) research has been designed and built at the TAPIRO fast research reactor. A complete experimental characterisation of the radiation field in the irradiation chamber has been performed, to verify agreement with IAEA requirements. Slow neutron fluxes have been measured by means of an activation technique and with thermoluminescent detectors (TLDs). The fast neutron dose has been determined with gel dosemeters, while the fast neutron spectrum has been acquired by means of a neutron spectrometer based on superheated drop detectors. The gamma-dose has been measured with gel dosemeters and TLDs. For an independent verification of the experimental results, fluxes, doses and neutron spectra have been calculated with Monte Carlo simulations using the codes MCNP4B and MCNPX 2.1.5 with the direct statistical approach (DSA). The results obtained confirm that the epithermal beams achievable at TAPIRO are of suitable quality for BNCT purposes. (authors)

  12. Neutron activation analysis in Romania

    International Nuclear Information System (INIS)

    Apostolescu, St.

    1985-01-01

    The following basic nuclear facilities are used for neutron activation analysis: a 2000 KW VVR-S Nuclear Reactor, a U-200 Cyclotron, a 30 MeV Betatron, several 14 MeV neutron generators and a king size High Voltage tandem Van de'Graaff accelerator. The main domains of application of the thermal neutron activation analysis are: geology and mining, processing of materials, environment and biology, achaeology. Epithermal neutron activation analysis has been used for determination of uranium and thorium in ores with high Th/U ratios or high rare earth contents. One low energy accelerator, used as 14.1 Mev neutron source, is provided with special equipmen for oxigen and low mass elements determination. An useful alternating way to support fast neutron activation analysis is an accurate theoretical description of the fast neutron induced reactions based on the statistical model (Hauser-Feubach STAPRE code) and the preequilibrium decay geometry dependent model. A gravitational sample changer has been installed at the end of a beam line of the Cyclotron, which enables to perform charged particles activation analysis for protein determination in grains

  13. Simulation study of the photon quality correction factors of ionization chambers for FiR 1 epithermal neutron beam

    International Nuclear Information System (INIS)

    Koivunoro, H.; Uusi-Simola, J.; Savolainen, S.; Kotiluoto, P.; Auterinen, I.; Kosunen, A.

    2006-01-01

    At FiR 1 BNCT facility in Finland, neutron-insensitive Mg(Ar) ionization chambers are used for photon dose measurements in an epithermal neutron beam. Previously, photon sensitivity factors for the chamber for the measurements in a water phantom in FiR 1 beam have been determined experimentally from measurements in 60 Co gamma and in a 6 MV clinical accelerator photon beams. However, the response of the ionization chamber in a water phantom depends on energy spectrum and angle of the photons and the secondary electrons created inside the phantom and may differ depending on type of the irradiation source (accelerator vs. an epithermal neutron beam). Also, the experimental sensitivity factor does not take into account the possible perturbations in the photon production in phantom caused by the ionization chamber materials. Therefore, it is necessary to determine the photon quality correction factors (k Qγ ) for the Mg(Ar) chamber at the FiR 1 beam through computer simulations. In this study, the k Qγ factors have been determined for Mg(Ar) chamber from Monte Carlo calculations of absorbed photon dose at two depths in a water phantom using MCNP code. The k qγ factors obtained with this method are compared to the sensitivity factors determined with measurements in an accelerator photon beam and to the k Qγ factors published previously. (author)

  14. Thermal and epithermal neutron fluence rate gradient measurements by PADC detectors in LINAC radiotherapy treatments-field

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, M. T., E-mail: mariate9590@gmail.com; Barros, H.; Pino, F.; Sajo-Bohus, L. [Universidad Simón Bolívar, Nuclear Physics Laboratory, Sartenejas, Caracas (Venezuela, Bolivarian Republic of); Dávila, J. [Física Médica C. A. and Universidad Central de Venezuela, Caracas (Venezuela, Bolivarian Republic of)

    2015-07-23

    LINAC VARIAN 2100 is where energetic electrons produce Bremsstrahlung radiation, with energies above the nucleon binding energy (E≈5.5MeV). This radiation induce (γ,n) and (e,e’n) reactions mainly in the natural tungsten target material (its total photoneutron cross section is about 4000 mb in a energy range from 9-17 MeV). These reactions may occur also in other components of the system (e.g. multi leaf collimator). During radiation treatment the human body may receive an additional dose inside and outside the treated volume produced by the mentioned nuclear reactions. We measured the neutron density at the treatment table using nuclear track detectors (PADC-NTD). These covered by a boron-converter are employed, including a cadmium filter, to determine the ratio between two groups of neutron energy, i.e. thermal and epithermal. The PADC-NTD detectors were exposed to the radiation field at the iso-center during regular operation of the accelerator. Neutron are determined indirectly by the converting reaction {sup 10}B(n,α){sup 7}Li the emerging charged particle leave their kinetic energy in the PADC forming a latent nuclear track, enlarged by chemical etching (6N, NaOH, 70°C). Track density provides information on the neutron density through calibration coefficient (∼1.6 10{sup 4} neutrons /track) obtained by a californium source. We report the estimation of the thermal and epithermal neutron field and its gradient for photoneutrons produced in radiotherapy treatments with 18 MV linear accelerators. It was obsered that photoneutron production have higher rate at the iso-center.

  15. The epithermal critical experiments; Experiences critiques avec des neutrons epitliermiques; Nadteplovye kriticheskie ehksperimenty; Experimentos criticos con neutrones epitermicos

    Energy Technology Data Exchange (ETDEWEB)

    Morewitz, H A; Carpenter, S O [Atomics International, Canoga Park, CA (United States)

    1962-03-15

    The epithermal critical experiments. The present phase of the advanced-epithermal-thorium-reactor programme consists of integral-reactor-physic s experiments designed to provide neutron-cross-section information in the 10-MeV to 1-keV range. A series of nine, multi-region, slow-fast, pseudospherica l critical assemblies of the honey- comb, split-table type are being studied. So far, three assemblies have' been run. The outer driver-decouple r region drives an interior U{sup 233}-Th fuelled spherical test region whose neutron-flux spectrum is successively degraded by increasing the graphite moderator to fuel ratio. A square-wave oscillator experiment defines the central reactivity worths of forty small samples of different materials to 10{sup -8} {Delta}k for each assembly. Additionally, intercalibrated artificial neutron sources are oscillated to determine the various central neutron importance functions. The spectra are obtained by fission-counter measurements with calibrated foils of different thresholds and by a Li{sup 6}-solid-state- counter sandwich spectrometer. A digital computer routine will be used to compile all measurements into a self-consistent library of spectrum averaged cross-sections. (author) [French] La phase actuelle du programme de reacteur au thorium a neutrons epithermiques comprend des experiences integrales de physique des reacteurs pour obtenir des renseignements sur les sections efficaces neutroniques pour la gamme d'energie comprise entre 1 keV et 10 MeV. Les auteurs etudient une serie de neuf ensembles critiques pseudospheriques, a plusieurs regions, a couplage neutrons lents et neutrons rapides du type a alveoles et a coeur divise. A ce jour, trois de ces ensembles ont ete mis en service. La region exterieure, mettant en service ou hors service, commande une zone d'essai interieure de forme spherique ou le combustible est constitue de {sup 233}U-Th, dont le spectre du flux de neutrons est degrade progressivement par augmentation du

  16. Methodological developments and applications of neutron activation analysis

    International Nuclear Information System (INIS)

    Kucera, J.

    2007-01-01

    The paper reviews the author's experience acquired and achievements made in methodological developments of neutron activation analysis (NAA) of mostly biological materials. These involve epithermal neutron activation analysis, radiochemical neutron activation analysis using both single- and multi-element separation procedures, use of various counting modes, and the development and use of the self-verification principle. The role of NAA in the detection of analytical errors is discussed and examples of applications of the procedures developed are given. (author)

  17. TRANSHEX, 2-D Thermal Neutron Flux Distribution from Epithermal Flux in Hexagonal Geometry

    International Nuclear Information System (INIS)

    Patrakka, E.

    1994-01-01

    1 - Description of program or function: TRANSHEX is a multigroup integral transport program that determines the thermal scalar flux distribution arising from a known epithermal flux in two- dimensional hexagonal geometry. 2 - Method of solution: The program solves the isotropic collision probability equations for a region-averaged scalar flux by an iterative method. Either a successive over-relaxation or an inner-outer iteration technique is applied. Flat flux collision probabilities between trigonal space regions with white boundary condition are utilized. The effect of epithermal flux is taken into consideration as a slowing-down source that is calculated for a given spatial distribution and 1/E energy dependence of the epithermal flux

  18. A preliminary investigation on the epithermal flux depression effect due to cadmium box in a multiplying medium

    International Nuclear Information System (INIS)

    Ahmad, A.

    1983-01-01

    Cadmium boxes are widely used as filter in Reactor Neutron Activation Analysis (RNAA) for the irradiation of samples in epithermal neutrons. By virtue of being an absorber the cadmium boxes produce epithermal flux depression in the medium surrounding them. A preliminary study of this effect was carried out (author)

  19. Shielding design of a treatment room for an accelerator-based epithermal neutron irradiation facility for BNCT

    International Nuclear Information System (INIS)

    Evans, J.F.; Blue, T.E.

    1996-01-01

    Protecting the facility personnel and the general public from radiation exposure is a primary safety concern of an accelerator-based epithermal neutron irradiation facility. This work makes an attempt at answering the questions open-quotes How much?close quotes and open-quotes What kind?close quotes of shielding will meet the occupational limits of such a facility. Shielding effectiveness is compared for ordinary and barytes concretes in combination with and without borated polyethylene. A calculational model was developed of a treatment room, patient open-quotes scatterer,close quotes and the epithermal neutron beam. The Monte Carlo code, MCNP, was used to compute the total effective dose equivalent rates at specific points of interest outside of the treatment room. A conservative occupational effective dose rate limit of 0.01 mSv h -1 was the guideline for this study. Conservative Monte Carlo calculations show that constructing the treatment room walls with 1.5 m of ordinary concrete, 1.2 m of barytes concrete, 1.0 m of ordinary concrete preceded by 10 cm of 5% boron-polyethylene, or 0.8 m of barytes concrete preceded by 10 cm of 5% boron-polyethylene will adequately protect facility personnel. 20 refs., 8 figs., 2 tabs

  20. In vitro biological effectiveness of JRR-4 epithermal neutron beam. Experiment under free air beam and in water phantom. Cooperative research

    CERN Document Server

    Yamamoto, T; Horiguchi, Y; Kishi, T; Kumada, H; Matsumura, A; Nose, T; Torii, Y; Yamamoto, K

    2002-01-01

    The surviving curve and the biological effectiveness factor of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at Japan Research Reactor No.4. Surviving fraction of V79 Chinese hamster cell with or without sup 1 sup 0 B was obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal neutron beam (TNB-2), which were used or planned to use for BNCT clinical trial. The cell killing effect of these neutron beams with or without the presence of sup 1 sup 0 B depended highly on the neutron beam used, according to the epithermal and fast neutron content in the beam. The biological effectiveness factor values of the boron capture reaction for ENB, TNB-1 and TNB-2 were 3.99+-0.24, 3.04+-0.19 and 1.43+-0.08, respectively. The biological effectiveness factor values of the high-LET dose components based on the hydrogen recoils and the nitrogen capture reaction were 2.50+-0.32, 2.34+-0.30 and 2.17+-0.28 for EN...

  1. In vitro biological effectiveness of JRR-4 epithermal neutron beam. Experiment under free air beam and in water phantom. Cooperative research

    International Nuclear Information System (INIS)

    Yamamoto, Tetsuya; Matsumura, Akira; Nose, Tadao; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Hori, Naohiko; Torii, Yoshiya; Horiguchi, Yoji

    2002-05-01

    The surviving curve and the biological effectiveness factor of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at Japan Research Reactor No.4. Surviving fraction of V79 Chinese hamster cell with or without 10 B was obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal neutron beam (TNB-2), which were used or planned to use for BNCT clinical trial. The cell killing effect of these neutron beams with or without the presence of 10 B depended highly on the neutron beam used, according to the epithermal and fast neutron content in the beam. The biological effectiveness factor values of the boron capture reaction for ENB, TNB-1 and TNB-2 were 3.99±0.24, 3.04±0.19 and 1.43±0.08, respectively. The biological effectiveness factor values of the high-LET dose components based on the hydrogen recoils and the nitrogen capture reaction were 2.50±0.32, 2.34±0.30 and 2.17±0.28 for ENB, TNB-1 and TNB-2, respectively. The biological effectiveness factor values of the neutron and photon components were 1.22±0.16, 1.23±0.16 and 1.21±0.16, respectively. The depth function of biological effectiveness factor in water phantom and the difference in biological effectiveness factor among boron compounds were also determined. The experimental determination of biological effectiveness factor outlined in this paper is applicable to the dose calculation for each dose component of the neutron beams and contribute to an accurate biological effectiveness factor as comparison with a neutron beam at a different facility employed in ongoing and planned BNCT clinical trials. (author)

  2. Elemental analysis of brazing alloy samples by neutron activation technique

    International Nuclear Information System (INIS)

    Eissa, E.A.; Rofail, N.B.; Hassan, A.M.; El-Shershaby, A.; Walley El-Dine, N.

    1996-01-01

    Two brazing alloy samples (C P 2 and C P 3 ) have been investigated by Neutron activation analysis (NAA) technique in order to identify and estimate their constituent elements. The pneumatic irradiation rabbit system (PIRS), installed at the first egyptian research reactor (ETRR-1) was used for short-time irradiation (30 s) with a thermal neutron flux of 1.6 x 10 1 1 n/cm 2 /s in the reactor reflector, where the thermal to epithermal neutron flux ratio is 106. Long-time irradiation (48 hours) was performed at reactor core periphery with thermal neutron flux of 3.34 x 10 1 2 n/cm 2 /s, and thermal to epithermal neutron flux ratio of 79. Activation by epithermal neutrons was taken into account for the (1/v) and resonance neutron absorption in both methods. A hyper pure germanium detection system was used for gamma-ray acquisitions. The concentration values of Al, Cr, Fe, Co, Cu, Zn, Se, Ag and Sb were estimated as percentages of the sample weight and compared with reported values. 1 tab

  3. Elemental analysis of brazing alloy samples by neutron activation technique

    Energy Technology Data Exchange (ETDEWEB)

    Eissa, E A; Rofail, N B; Hassan, A M [Reactor and Neutron physics Department, Nuclear Research Centre, Atomic Energy Authority, Cairo (Egypt); El-Shershaby, A; Walley El-Dine, N [Physics Department, Faculty of Girls, Ain Shams Universty, Cairo (Egypt)

    1997-12-31

    Two brazing alloy samples (C P{sup 2} and C P{sup 3}) have been investigated by Neutron activation analysis (NAA) technique in order to identify and estimate their constituent elements. The pneumatic irradiation rabbit system (PIRS), installed at the first egyptian research reactor (ETRR-1) was used for short-time irradiation (30 s) with a thermal neutron flux of 1.6 x 10{sup 1}1 n/cm{sup 2}/s in the reactor reflector, where the thermal to epithermal neutron flux ratio is 106. Long-time irradiation (48 hours) was performed at reactor core periphery with thermal neutron flux of 3.34 x 10{sup 1}2 n/cm{sup 2}/s, and thermal to epithermal neutron flux ratio of 79. Activation by epithermal neutrons was taken into account for the (1/v) and resonance neutron absorption in both methods. A hyper pure germanium detection system was used for gamma-ray acquisitions. The concentration values of Al, Cr, Fe, Co, Cu, Zn, Se, Ag and Sb were estimated as percentages of the sample weight and compared with reported values. 1 tab.

  4. Reactor AQUILON. The hardening of neutron spectrum in natural uranium rods, with a computation of epithermal fissions (1961); Pile AQUILON. Durcissement du spectre des neutrons dans les barreaux d'uranium et calcul des fissions epithermiques (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Durand -Smet, R; Lourme, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    - Microscopic flux measurements in reactor Aquilon have allowed to investigate the thermal and epithermal flux distribution in natural uranium rods, then to obtain the neutron spectrum variations in uranium, Wescott '{beta}' term of the average spectrum in the rod, and the ratio of epithermal to therma fissions. A new definition for the infinite multiplication factor is proposed in annex, which takes into account epithermal parameters. (authors) [French] - Un certain nombre de mesures effectuees dans la pile Aquilon ont permis d'etablir la distribution fine des flux thermique et epithermique dans les barreaux d'uranium, et d'en deduire les variations du spectre des neutrons dans l'uranium, le terme {beta} du spectre de Wescott moyen dans le barreau et le nombre de fissions epithermiques. En annexe, il est propose une definition nouvelle du coefficient de multiplication infini, qui fait intervenir les parametres epithermiques. (auteurs)

  5. Filtered epithermal quasi-monoenergetic neutron beams at research reactor facilities.

    Science.gov (United States)

    Mansy, M S; Bashter, I I; El-Mesiry, M S; Habib, N; Adib, M

    2015-03-01

    Filtered neutron techniques were applied to produce quasi-monoenergetic neutron beams in the energy range of 1.5-133keV at research reactors. A simulation study was performed to characterize the filter components and transmitted beam lines. The filtered beams were characterized in terms of the optimal thickness of the main and additive components. The filtered neutron beams had high purity and intensity, with low contamination from the accompanying thermal emission, fast neutrons and γ-rays. A computer code named "QMNB" was developed in the "MATLAB" programming language to perform the required calculations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Absolute instrumental neutron activation analysis at Lawrence Livermore Laboratory

    International Nuclear Information System (INIS)

    Heft, R.E.

    1977-01-01

    The Environmental Science Division at Lawrence Livermore Laboratory has in use a system of absolute Instrumental Neutron Activation Analysis (INAA). Basically, absolute INAA is dependent upon the absolute measurement of the disintegration rates of the nuclides produced by neutron capture. From such disintegration rate data, the amount of the target element present in the irradiated sample is calculated by dividing the observed disintegration rate for each nuclide by the expected value for the disintegration rate per microgram of the target element that produced the nuclide. In absolute INAA, the expected value for disintegration rate per microgram is calculated from nuclear parameters and from measured values of both thermal and epithermal neutron fluxes which were present during irradiation. Absolute INAA does not depend on the concurrent irradiation of elemental standards but does depend on the values for thermal and epithermal neutron capture cross-sections for the target nuclides. A description of the analytical method is presented

  7. Physical parameters and biological effects of the LVR-15 epithermal neutron beam

    Czech Academy of Sciences Publication Activity Database

    Burian, J.; Gambarini, G.; Marek, M.; Mareš, Vladislav; Rejchrt, J.; Vanossi, E.; Viererbl, L.; Judas, L.

    -, - (2006), s. 481-484 [International Congress on Neutron Capture Therapy /12./. Kagawo, 09.10.2006-13.10.2006] R&D Projects: GA MPO(CZ) 1H-PK2/05 Institutional research plan: CEZ:AV0Z50110509 Keywords : brain tumors * neutron capture therapy * NTC * dosimetry Subject RIV: FD - Oncology ; Hematology

  8. Cadmium-Zinc-Telluride photon detector for epithermal neutron spectroscopy--pulse height response characterisation

    International Nuclear Information System (INIS)

    Tardocchi, M.; Pietropaolo, A.; Andreani, C.; Bracco, A.; D'Angelo, A.; Gorini, G.; Imberti, S.; Senesi, R.; Rhodes, N.J.; Schooneveld, E.M.

    2004-01-01

    The Resonance Detector Spectrometer was recently revised for neutron spectroscopic studies in the eV energy region. In this technique one makes use of a photon detector to record the gamma emission from analyser foils used as neutron-gamma converters. The pulse-height response of a Cadmium-Zinc-Telluride photon detector to neutron capture emission from 238 U and 197 Au analyser foils was characterised in the neutron energy range 1-200 eV. The experiment was performed on the VESUVIO spectrometer at the ISIS neutron-pulsed source. A biparametric data acquisition, specifically developed for these measurements, allowed the simultaneous measurements of both the neutron time of flight and γ pulse-height spectra. Through the analysis of the γ pulse-height spectra the main components of the signal associated with resonant and non-resonant neutron absorption were identified. It was also shown that, in principle, energy discrimination can be used to improve the signal to background ratio of the neutron time-of-flight measurement

  9. Single-crystal filters for attenuating epithermal neutrons and gamma rays in reactor beams

    DEFF Research Database (Denmark)

    Rustad, B.M.; Als-Nielsen, Jens Aage; Bahnsen, A.

    1965-01-01

    Cross section of representative samples of bismuth and quartz were measured at room and liquid nitrogen temperatures over neutron energy range of 0.0007 to 2.0 ev to obtain data for design of single-crystal 32-cm bismuth filters for attenuating fast neutrons and γ-rays in reactor beams; filters may...

  10. Simulation study of accelerator based quasi-mono-energetic epithermal neutron beams for BNCT.

    Science.gov (United States)

    Adib, M; Habib, N; Bashter, I I; El-Mesiry, M S; Mansy, M S

    2016-01-01

    Filtered neutron techniques were applied to produce quasi-mono-energetic neutron beams in the energy range of 1.5-7.5 keV at the accelerator port using the generated neutron spectrum from a Li (p, n) Be reaction. A simulation study was performed to characterize the filter components and transmitted beam lines. The feature of the filtered beams is detailed in terms of optimal thickness of the primary and additive components. A computer code named "QMNB-AS" was developed to carry out the required calculations. The filtered neutron beams had high purity and intensity with low contamination from the accompanying thermal, fast neutrons and γ-rays. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Design of an irradiation facility with thermal, epithermal and fast neutron beams

    International Nuclear Information System (INIS)

    Pfister, G.; Bernnat, W.; Seidel, R.; Schatz, A.K.; Wagner, F.M.; Waschkowski, W.; Schraube, H.

    1992-01-01

    The main features of a neutron irradiation facility to be installed at the planned research reactor FRM-II are presented. In addition to the operational possibilities of the existing facility at the reactor FRM-I, the new facility will produce quasi-monoenergetic neutron fields and a neutron beam in the keV region whose spectrum can be modified by application of suitable filters and scatterers. For this beam, which is well suited for boron capture therapy, calculated boron reaction rates inside a phantom and an experimental verification of the calculations at the existing facility are presented. (orig.) [de

  12. The orientation effect in the activities of neutronic probes; Efecto de orientacion en las actividades de sondas neutronicas

    Energy Technology Data Exchange (ETDEWEB)

    Vigon, M A

    1956-07-01

    The formulae relating activity and position of a neutron irradiated Indium foil, have been verified experimentally. Measurements with both thin and thick foils for epithermal neutrons and with thick foils for thermal neutrons have been carried out. The experimental results agree qualitatively with the theoretical predictions. (Author)

  13. Microscopic cross-section measurements by thermal neutron activation

    International Nuclear Information System (INIS)

    Avila L, J.

    1987-08-01

    Microscopic cross sections measured by thermal neutron activation using RP-0 reactor at the Peruvian Nuclear Energy Institute. The method consists in measuring microscopic cross section ratios through activated samples, requiring being corrected in thermal and epithermal energetic range by Westcott formalism. Furthermore, the comptage ratios measured for each photopeak to its decay fraction should be normalized from interrelation between both processes above, activation microscopic cross sections are obtained

  14. The background cross section method for calculating the epithermal neutron spectra

    International Nuclear Information System (INIS)

    Martinez, A.S.

    1983-01-01

    We have developed a new methodology to the multigroup constants calculations, for thermal and fast reactors. The method to obtain the constants is extremely fast and simple, and it avoid repeated computations of the detailed neutron spectrum for different cell configurations (composition, geometry and temperature). (author) [pt

  15. A neutron activation detector

    International Nuclear Information System (INIS)

    Ambardanishvili, T.S.; Kolomiitsev, M.A.; Zakharina, T.Y.; Dundua, V.J.; Chikhladze, N.V.

    1973-01-01

    The present invention concerns a neutron activation detector made from a moulded and hardened composition. According to the invention, that composition contains an activable substance constituted by at least two chemical elements and/or compounds of at least two chemical elements. Each of these chemical elements is capable of reacting with the neutrons forming radio-active isotopes with vatious levels of energy during desintegration. This neutron detector is mainly suitable for measuring integral thermal neutron and fast neutron fluxes during irradiation of the sample, and also for measuring the intensities of neutron fields [fr

  16. Neutron activation determination of impurities in molybdenum

    International Nuclear Information System (INIS)

    Usmanova, M.M.; Mukhamedshina, N.M.; Obraztsova, T.V.; Saidakhmedov, K.Kh.

    1984-01-01

    Instrumental neutron-activation techniques of impurity element determination in molybdenum and MoO 3 (solid and powdered samples) have been developed. When determining impurities of Na, K, Mn, Cu, W, Re molybdenum has been irradiated by thermal neutrons in reactor for 20 min, the sample mass constituted 200-300 mg, sample cooling time after irradiation - 2.5-3.5 h. It is shown that in the process of Cr, Fe, Co, Zn determination the samples should be irradiated with thermal neutrons, and in the process of Sb, Ta and Ni determination - with resonance and fast neutrons. Simultaneous determination of the elements during irradiation with neutrons with reactor spectrum is possible. When determining P and S the samples are irradiated with thermal and epithermal neutrons and β-activity of samples and comparison samples are measured using β-spectrometer with anthracene crystal. The techniques developed permit to determine impurities in Mo with a relative standard deviation 0.07-0.15 and lower boundaries of contents determined - 10 -4 - 10 -7 %

  17. Methods of Reducing Bias in Combined Thermal/Epithermal Neutron (CTEN) Assays of Heterogeneous Waste

    Energy Technology Data Exchange (ETDEWEB)

    Estep, R.J.; Melton, S.; Miko, D.

    1998-11-17

    We examined the effectiveness of two different methods for correcting CTEN passive and active assays for bias due to variations in the source position in different drum types. Both use the same drum-averaged correction determined from a neural network trained to active flux monitor ratios as a starting point. One method then uses a neural network to obtain a spatial correction factor sensitive to the source location. The other method uses emission tomography. Both methods were found to give significantly improved assay accuracy over the drum-averaged correction, although more study is needed to determine which method works better.

  18. Methods of Reducing Bias in Combined Thermal/Epithermal Neutron (CTEN) Assays of Heterogeneous Waste

    International Nuclear Information System (INIS)

    Estep, R.J.; Melton, S.; Miko, D.

    1998-01-01

    We examined the effectiveness of two different methods for correcting CTEN passive and active assays for bias due to variations in the source position in different drum types. Both use the same drum-averaged correction determined from a neural network trained to active flux monitor ratios as a starting point. One method then uses a neural network to obtain a spatial correction factor sensitive to the source location. The other method uses emission tomography. Both methods were found to give significantly improved assay accuracy over the drum-averaged correction, although more study is needed to determine which method works better

  19. Epithermal interrogation of fissile waste

    International Nuclear Information System (INIS)

    Coop, K.L.; Hollas, C.L.

    1996-01-01

    Self-shielding of interrogating thermal neutrons in lumps of fissile material can be a major source of error in transuranic waste assay using the widely employed differential dieaway technique. We are developing a new instrument, the combined thermal/epithermal neutron (CTEN) interrogation instrument to detect the occurrence of self- shielding and mitigate its effects. Neutrons are moderated in the graphite walls of the CTEN instrument to provide an interrogating flux of epithermal and thermal neutrons. The induced prompt fission neutrons are detected in proportional counters. We report the results of measurements made with the CTEN instrument, using minimal and highly self-shielding plutonium and uranium sources in 55 gallon drums containing a variety of mock waste matrices. Fissile isotopes and waste forms for which the method is most applicable, and limitations associated with the hydrogen content of the waste package/matrix are described

  20. Epithermal beam development at the BMRR [Brookhaven Medical Research Reactor]: Dosimetric evaluation

    International Nuclear Information System (INIS)

    Saraf, S.K.; Fairchild, R.G.; Kalef-Ezra, J.; Laster, B.H.; Fiarman, S.; Ramsey, E.; Ioannina Univ.; Brookhaven National Lab., Upton, NY; State Univ. of New York, Stony Brook, NY

    1989-01-01

    The utilization of an epithermal neutron beam for neutron capture therapy (NCT) is desirable because of the increased tissue penetration relative to a thermal neutron beam. Over the past few years, modifications have been and continue to be made at the Brookhaven Medical Research Reactor (BMRR) by changing its filter components to produce an optimal epithermal beam. An optimal epithermal beam should contain a low fast neutron contamination and no thermal neutrons in the incident beam. Recently a new moderator for the epithermal beam has been installed at the epithermal port of the BMRR and has accomplished this task. This new moderator is a combination of alumina (Al 2 O 3 ) bricks and aluminum (Al) plates. A 0.51 mm thick cadmium (Cd) sheet has reduced the thermal neutron intensity drastically. Furthermore, an 11.5 cm thick bismuth (Bi) plate installed at the port surface has reduced the gamma dose component to negligible levels. Foil activation techniques have been employed by using bare gold and cadmium-covered gold foil to determine thermal as well as epithermal neutron fluence. Fast neutron fluence has been determined by indium foil counting. Fast neutron and gamma dose in soft tissue, free in air, is being determined by the paired ionization chamber technique, using tissue equivalent (TE) and graphite chambers. Thermoluminescent dosimeters (TLD-700) have also been used to determine the gamma dose independently. This paper describes the methods involved in the measurements of the above mentioned parameters. Formulations have been developed and the various corrections involved have been detailed. 12 refs

  1. Activation neutron detector

    International Nuclear Information System (INIS)

    Ambardanishvili, T.S.; Kolomiitsev, M.A.; Zakharina, T.Y.; Dundua, V.J.; Chikhladze, N.V.

    1976-01-01

    An activation neutron detector made as a moulded and cured composition of a material capable of being neutron-activated is described. The material is selected from a group consisting of at least two chemical elements, a compound of at least two chemical elements and their mixture, each of the chemical elements and their mixture, each of the chemical elements being capable of interacting with neutrons to form radioactive isotopes having different radiation energies when disintegrating. The material capable of being neutron-activated is distributed throughout the volume of a polycondensation resin inert with respect to neutrons and capable of curing. 17 Claims, No Drawings

  2. A prospect for the development of an epithermal neutron beam from the horizontal channel at the TRNC for brain tumors treatment based on the BNCT method

    International Nuclear Information System (INIS)

    Ben-Ghazail, Mustafa Ali

    2005-01-01

    In this work the epithermal neutron was development from horizontal channel VI at Tajoura research reactor which can be used for Boron Neutron Capture Therapy. The analysis of reactivity and control rod worth is performed by three dimensional continues energy MCNP-4C code with neutron cross section data from the ENDF/B-VI evaluation. The neutron beam which is developed for medical purpose is generated from the reactor core by means of U-235 fission. The neutrons leaking through the cavity of HC in Be-9 reflector is guided through a tube made of stainless steel to patient position. The HC has two wheels. The first wheel is small and is used as a gate. The second is large and have three positions one to close the gate, the second to open the gate while the third for loading collimator. The collimator consists of the moderators and filters to optimize the neutron beam which is installed in the loading position. The HC VI is extended to the room constructed to allow space for other horizontal channels users. materials are used to optimize the neutron beam which was selected depending on neutron beam properties related to core loading and control rod position. The results of the development study show that the required values for the neutron beam characteristic can be nearly reached. The different comparisons of the calculations performed using MCNP-4C code with the requirements values of characteristics neutron beam show that the result values of MCNP-4C code model are reliable. (author)

  3. Boron neutron capture therapy of glioblastoma multiforme using the p- boronophenylalanine-fructose complex and epithermal neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Coderre, J.A.; Chanana, A.D.; Joel, D.D.; Liu, H.B.; Slatkin, D.N.; Wielopolski, L. [Brookhaven National Lab., Upton, NY (United States); Bergland, R.; Elowitz, E. [Beth Israel Medical Center, New York, NY (United States). Dept. of Neurosurgery; Chadha, M. [Beth Israel Medical Center, New York, NY (United States). Dept. of Radiation Oncology

    1994-12-31

    The amino acid analogue p-boronophenylalanine (BPA) is under investigation as a neutron capture agent for BNCT of glioblastoma multiforme. A series of patients undergoing surgical removal of tumor received BPA orally as the free amino acid. Favorable tumor/blood boron concentration ratios were obtained but the absolute amount of boron in the tumor would have been insufficient for BNCT. BPA can be solubilized at neutral pH by complexation with fructose (BPA-F). Studies with rats suggest that intraperitoneal injection of BPA-F complex produces a much higher tumor boron concentration to rat intracerebral 9L gliosarcoma that were possible with oral BPA. Higher boron concentrations have allowed higher tumor radiation doses to be delivered while maintaining the dose to the normal brain vascular endothelium below the threshold of tolerance. The experience to date of the administration of BPA-F to one patient is provided in this report.

  4. Boron neutron capture therapy of glioblastoma multiforme using the p- boronophenylalanine-fructose complex and epithermal neutrons

    International Nuclear Information System (INIS)

    Coderre, J.A.; Chanana, A.D.; Joel, D.D.; Liu, H.B.; Slatkin, D.N.; Wielopolski, L.; Bergland, R.; Elowitz, E.; Chadha, M.

    1994-01-01

    The amino acid analogue p-boronophenylalanine (BPA) is under investigation as a neutron capture agent for BNCT of glioblastoma multiforme. A series of patients undergoing surgical removal of tumor received BPA orally as the free amino acid. Favorable tumor/blood boron concentration ratios were obtained but the absolute amount of boron in the tumor would have been insufficient for BNCT. BPA can be solubilized at neutral pH by complexation with fructose (BPA-F). Studies with rats suggest that intraperitoneal injection of BPA-F complex produces a much higher tumor boron concentration to rat intracerebral 9L gliosarcoma that were possible with oral BPA. Higher boron concentrations have allowed higher tumor radiation doses to be delivered while maintaining the dose to the normal brain vascular endothelium below the threshold of tolerance. The experience to date of the administration of BPA-F to one patient is provided in this report

  5. Neutron activation analysis of geochemical samples

    International Nuclear Information System (INIS)

    Rosenberg, R.; Zilliacus, R.; Kaistila, M.

    1983-06-01

    The present paper will describe the work done at the Technical Research Centre of Finland in developing methods for the large-scale activation analysis of samples for the geochemical prospecting of metals. The geochemical prospecting for uranium started in Finland in 1974 and consequently a manually operated device for the delayed neutron activation analysis of uranium was taken into use. During 1974 9000 samples were analyzed. The small capacity of the analyzer made it necessary to develop a completely automated analyzer which was taken into use in August 1975. Since then 20000-30000 samples have been analyzed annually the annual capacity being about 60000 samples when running seven hours per day. Multielemental instrumental neutron activation analysis is used for the analysis of more than 40 elements. Using instrumental epithermal neutron activation analysis 25-27 elements can be analyzed using one irradiation and 20 min measurement. During 1982 12000 samples were analyzed for mining companies and Geological Survey of Finland. The capacity is 600 samples per week. Besides these two analytical methods the analysis of lanthanoids is an important part of the work. 11 lanthanoids have been analyzed using instrumental neutron activation analysis. Radiochemical separation methods have been developed for several elements to improve the sensitivity of the analysis

  6. Boron neutron capture therapy (BNCT) for glioblastoma multiforme (GBM), using the epithermal neutron beam at the Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    Chadha, Manjeet; Capala, Jacek; Coderre, Jeffrey A.; Elowitz, Eric H.; Joel, Darrel D.; Hungyuan, B. Liu; Slatkin, Daniel N.; Chanana, Arjun D.

    1996-01-01

    Objective: BNCT is a binary treatment modality based on the nuclear reactions that occur when boron ( 10 B) is exposed to thermal neutrons. Preclinical studies have demonstrated the therapeutic efficacy of p-boronophenylalanine (BPA)-based BNCT. The objective of the Phase I/II trial was to evaluate BPA-fructose (BPA-F) as a boron delivery agent for GBM and to study the feasibility and safety of a single-fraction of BNCT. Materials and Methods: The trial design required i) a BPA-F biodistribution study performed at the time of craniotomy; and ii) BNCT within 4 weeks of the craniotomy. From September 94 to July 95, 10 patients with biopsy proven GBM were treated. All but 1 patient underwent a biodistribution study receiving IV BPA-F at the time of craniotomy. Multiple tissue samples and concurrent blood and urine samples were collected for evaluation of the boron concentration and clearance kinetics. For BNCT all patients received 250 mg/kgm of BPA-F (IV infusion over 2 hrs) followed by neutron irradiation. The blood 10 B concentration during irradiation was used to calculate the time of neutron exposure. The 3D treatment planning was done using the BNCT treatment planning software developed at the Idaho National Engineering Laboratory. The BNCT dose is expressed as the sum of the physical dose components corrected for both the RBE and the 10 B localization factor with the unit Gy-Eq. The photon-equivalent dose, where the thermal neutron fluence reaches a maximum, is the peak-dose equivalent. A single-fraction of BNCT was delivered prescribing 10.5 Gy-Eq (9 patients) and 13.8 Gy-Eq (1 patient) as the peak dose-equivalent to the normal brain. The peak dose rate was kept below 27 cGy-Eq/min. Results: Biodistribution data: The maximum blood 10 B concentration was observed at the end of the infusion and scaled as a linear function of the administered dose. The 10 B concentration in the scalp and in the GBM tissue was higher than in blood by 1.5 x and at least 3.5 x

  7. Pulse neutron logging technique

    International Nuclear Information System (INIS)

    Bespalov, D.F.; Dylyuk, A.A.

    1975-01-01

    A new method of neutron-burst logging is proposed, residing in irradiating rocks with fast neutron bursts and registering the integrated flux burst of thermal and/or epithermal neutrons, from the moment of its initiation to that of full absorption. The obtaained value is representative of the rock properties (porosity, hydrogen content). The integrated flux in a burst of thermal and epithermal neutrons can be measured both by way of activation of a reference sample of a known chemical composition during the neutron burst and by recording the radiation of induced activity of the sample within an interval between two bursts. The proposed method features high informative value, accuracy and efficiency

  8. Activation analysis by filtered neutrons. Preliminary investigation

    International Nuclear Information System (INIS)

    Skarnemark, G.; Rodinson, T.; Skaalberg, M.; Tokay, R.K.

    1986-01-01

    In order to investigate if measuring sensibility and precision by epithermal neutron activation analysis may be improved, different types of geological and biologic test samples were radiated. The test samples were enclosed in an extra filter of tungsten or sodium in order to reduce the flux of those neutrons that otherwise would induce interfering activity in the sample. The geological test samples consist of granites containing lanthanides which had been crushed in tung- sten carbide grinder. Normally such test samples show a interferins 1 87W-activity. By use of a tungsten filter the activity was reduced by up to 60%, which resulted in a considerable improvement of sensibility and precision of the measurement. The biologic test samples consisted of evaporated urine from patients treated with the cell poison cis-platinol. A reliable method to measure the platinum content has not existed so far. This method, however, enables platinum contents as low as about 0.1 ppm to be determined which is quite adequate. To sum up this preliminary study has demonstrated that activation analysis using filtered neutrons, correctly applied, is a satisfactory method of reducing interferences without complicated and time-consuming chemical separation procedures. (O.S.)

  9. Forensic neutron activation analysis

    International Nuclear Information System (INIS)

    Kishi, T.

    1987-01-01

    The progress of forensic neutron activation analysis (FNAA) in Japan is described. FNAA began in 1965 and during the past 20 years many cases have been handled; these include determination of toxic materials, comparison examination of physical evidences (e.g., paints, metal fragments, plastics and inks) and drug sample differentiation. Neutron activation analysis is applied routinely to the scientific criminal investigation as one of multielement analytical techniques. This paper also discusses these routine works. (author) 14 refs

  10. Elemental Study in Soybean and Products by Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Vorapot, Permnamtip; Arporn Busamongkol; Sirinart, Laoharojanaphand

    2009-07-01

    Full text: Elements were analyzed in soybean and products by Instrumental Neutron Activation Analysis (INAA), Pseudo-Cyclic Instrumental Neutron Activation Analysis (PCINAA) and Epithermal Instrumental Neutron Activation Analysis (EINAA). Elements detected in sample were include Al, Br, Ca, Cl, Cu, Fe, I, K, Mg, Mn Na, Se and Zn. The result showed that the nutritional contents changed after food processing. From experiments (n = 2), it was found that after food processing, the concentration of Cl and Na in soy bean curd increased from 0.0045 and 0.0011% to found 0.91 and 0.39 %, respectively. Other elements did not differ from soybean. Limits of detection for Al, Br, Ca, Cl, Cu, Fe, I, K, Mg, Mn Na, Se and Zn were 0.05, 0.2, 50, 6, 10, 15, 0.05, 30, 40, 5, 5, 0.05 and 1 mg.kg - 1, respectively

  11. Neutron activation analysis of gold and prospectiveness of its application

    International Nuclear Information System (INIS)

    Tong Chunhan.

    1988-01-01

    NAA of gold is a method of high sensitivity and high percision, especially when epithermal neutron activation is applied. NAA is particularly emphasized in the process of gold reference standards preparation. In addition to the pure instrumental NAA, the NAA with pre-enrichment before sctivation is developed. This technque has been successfully used in assessment of micro and fine grained Au-Ag-phlymetal ores in Guixian, Guangxi. Through this example, prospectiveness of NAA application in Au-Ag-prospecting, fast assessment and trace element geochemistry investigation is seen

  12. Isotopic neutron sources for neutron activation analysis

    International Nuclear Information System (INIS)

    Hoste, J.

    1988-06-01

    This User's Manual is an attempt to provide for teaching and training purposes, a series of well thought out demonstrative experiments in neutron activation analysis based on the utilization of an isotopic neutron source. In some cases, these ideas can be applied to solve practical analytical problems. 19 refs, figs and tabs

  13. Multi-element neutron activation analysis of Brazilian coal samples

    International Nuclear Information System (INIS)

    Atalla, L.T.; Requejo, C.S.

    1982-09-01

    The elements U, Th, La, Ce, Nd, Sm, Eu, Dy, Tb, Yb, Lu, Sc, Ta, Hf, Co, Ni, Cr, Mo, Ti, V, W, In, Ga, Mn, Ba, Sr, Mg, Rb, Cs, K, Cl, Br, As, Sb, Au, Ca, Al and Fe were determined in coal samples by instrumental neutron activation analysis, by using both thermal and epithermal neutron irradiations. The irradiation times were 10 minutes and 8 or 16 hours in a position where the thermal neutron flux was about 10 12 n.cm - 2 .s - 1 and 72 non-consecutive hours for epithermal irradiation at a flux of about 10 11 n.Cm - 2 .s - 1 . After the instrumental analysis of the above mentioned elements, Zn and Se were determined with chemical separation. The relative standard deviation of, at least, 4 determinations was about + - 10% for the majority of the results. The coal samples analysed were supplied by: Cia. Estadual da Tecnologia e Saneamento Basico (CETESB-SP), Cia. de Pesquisas e Lavras Minerais (COPELMI-RS), Cia. Carbonifera Urussunga (SC), Cia. Carbonifera Prospera (SC), Cia. Carbonifera Treviso (SC), Cia. Nacional de Mineracao de Carvao do Barro Branco (SC) and Comissao Nacional de Energia Nuclear (CNEN-RJ). (Author) [pt

  14. Activation method for measurement of neutron spectrum parameters

    International Nuclear Information System (INIS)

    Efimov, B.V.; Demidov, A.M.; Ionov, V.S.; Konjaev, S.I.; Marin, S.V.; Bryzgalov, V.I.

    2007-01-01

    Experimental researches of spectrum parameters of neutrons at nuclear installations RRC KI are submitted. The installations have different designs of the cores, reflector, parameters and types of fuel elements. Measurements were carried out with use of the technique developed in RRC KI for irradiation resonance detectors UKD. The arrangement of detectors in the cores ensured possibility of measurement of neutron spectra with distinguished values of parameters. The spectrum parameters which are introduced by parametrical representation of a neutrons spectrum in the form corresponding to formalism Westcott. On experimental data were determinate absolute values of density neutron flux (DNF) in thermal and epithermal area of a spectrum (F t , f epi ), empirical dependence of temperature of neutron gas (Tn) on parameter of a rigidity of a spectrum (z), density neutron flux in transitional energy area of the spectrum. Dependences of spectral indexes of nuclides (UDy/UX), included in UKD, from a rigidity z and-or temperatures of neutron gas Tn are obtained.B Tools of mathematical processing of results are used for activation data and estimation of parameters of a spectrum (F t , f epi , z, Tn, UDy/UX). In the paper are presented some results of researches of neutron spectrum parameters of the nuclear installations (Authors)

  15. Determination of silicon in biological and botanical reference materials by epithermal INAA and Compton suppression

    International Nuclear Information System (INIS)

    Landsberger, S.; Peshev, S.; Becker, D.A.

    1994-01-01

    Silicon determination in sixteen botanical and biological standard reference materials is described using the 29 Si(n, p) 29 Al reaction through instrumental epithermal neutron activation analysis and Compton suppression gamma-ray spectroscopy. By simultaneous utilization of both cadmium and boron epithermal filters along with anticoincidence gamma-counting, detection limits as low as 12 ppm were obtained for certain matrices, much lower than previously reported values for this type of analysis. The method is applicable to many botanical and biological matrices and is attractive with its interference free, purely instrumental nature, compared with methods using the 28 Si(n, p) 28 Al reaction or chemical separation techniques. ((orig.))

  16. Fast neutron activation analysis

    International Nuclear Information System (INIS)

    Pepelnik, R.

    1986-01-01

    Since 1981 numerous 14 MeV neutron activation analyses were performed at Korona. On the basis of that work the advantages of this analysis technique and therewith obtained results are compared with other analytical methods. The procedure of activation analysis, the characteristics of Korona, some analytical investigations in environmental research and material physics, as well as sources of systematic errors in trace analysis are described. (orig.) [de

  17. Educational activities for neutron sciences

    International Nuclear Information System (INIS)

    Hiraka, Haruhiro; Ohoyama, Kenji; Iwasa, Kazuaki

    2011-01-01

    Since now we have several world-leading neutron science facilities in Japan, enlightenment activities for introducing neutron sciences, for example, to young people is an indispensable issue. Hereafter, we will report present status of the activities based on collaborations between universities and neutron facilities. A few suggestions for future educational activity of JSNS are also shown. (author)

  18. Neutron activation studies on JET

    International Nuclear Information System (INIS)

    Loughlin, M.J.; Forrest, R.A.; Edwards, J.E.G.

    2001-01-01

    Extensive neutron transport calculations have been performed to determine the neutron spectrum at a number of points throughout the JET torus hall. The model has been bench-marked against a set of foil activation measurements which were activated during an experimental campaign with deuterium/tritium plasmas. The model can predict the neutron activation of the foils on the torus hall walls to within a factor of three for reactions with little sensitivity to thermal neutrons. The use of scandium foils with and without a cadmium thermal neutron absorber was a useful monitor of the thermal neutron flux. Conclusions regarding the usefulness of other foils for benchmarking the calculations are also given

  19. Rapid determination of halogenes in milk by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Alfassi, Z.B.; Lavi, N.

    1985-01-01

    The absolute concetrations of iodine, bromine and chlorine in milk were determined by epithermal neutron activation followed by high resolution gamma-ray spectrometry. Two kinds of milk commonly consumed in Israel were investigated. The concentration of iodine, bromine and chlorine were found to be 0.18-0.30 μg/ml, 2.02-2.85 μg/ml and 0.65 mg/ml, respectively. The method is fast, selective, accurate and highly sensitive. (author)

  20. Activation method for measuring the reaction rates and studying the neutron spectra parameters, based on using the unified composition detectors

    International Nuclear Information System (INIS)

    Demidov, A.M.; Dikarev, V.S.; Efimov, B.V.; Ionov, V.S.; Marin, S.V.

    2005-01-01

    The method proposed for estimation of parameters thermal and epithermal parts of energy distribution of neutrons is described. The method based on application of activation measuring with use of unified composition detectors (UCD) and samples of fuel. The method is applicable for definition of neutron spectrum parameters and velocities of division in fuel of nuclear installations. Theoretical bases and the description of a method, expedients of manufacturing and calibration for the detectors, the experimental data, carried out in RRC KI are given and processing of experimental data, and also. The parametric model of a spectrum constructed on the basis of Westcott's formalism is described. The parameter of stiffness is entered and its role for temperature of neutron gas, spectral coefficients of isotopes of detectors, the transition area thermal and epithermal parts of neutron spectra is observationally appreciated. It is offered to confirm the found results by calculations with use of MCU Monte Carlo code [ru

  1. Neutron activation analysis

    International Nuclear Information System (INIS)

    Taure, I.; Riekstina, D.; Veveris, O.

    2004-01-01

    Neutron activation analysis (NAA) in Latvia began to develop after 1961 when nuclear reactor in Salaspils started to work. It provided a powerful neuron source, which is necessary for this analytical method. In 1963 at Institute of Physics of the Latvian Academy of Sciences the Laboratory of Neutron Activation Analysis was formed. At the first stage of development the main tasks were of theoretical and technical aspects of NAA. Later the NAA was used to solve problems in technology, biology, and medicine. In the beginning of the 80-ties more attention was focussed to the use of NAA in the environmental research. Environmental problems stayed the main task till the closing the nuclear reactor in Salaspils in 1998 that ceased the main the existence of the laboratory and of NAA, this significant and powerful analytical method in Latvia and Baltic in general. (authors)

  2. Neutron activation analysis at the 'Instituto de Pesquisas Energeticas e Nucleares' (SP, Brazil)

    International Nuclear Information System (INIS)

    Vasconcellos, M.B.A.

    1984-01-01

    A review of the work carried out at IPEN using neutron activation analysis is made. The main characteristics of the technique and general experimental procedures applied for different samples and elements are reported. Geological samples were analysed by using activation with thermal, epithermal and delayed neutrons (for U and Th, specifically). Metallic samples were analysed for several elements in trace amounts (Ta in Nb, Hg in steel, Sn, Sb, As, Cu, Cr and Ag in a tin-lead alloy). Biological materials, such as tomatoes, animal and human viscera, food, hair, nails were also analysed for several components (Hg, Na, K, As, Au and others). (Author) [pt

  3. The instrumental neutron-activation analysis of granites from the Bushveld Complex

    International Nuclear Information System (INIS)

    Watterson, J.I.W.

    1978-01-01

    Three methods of instrumental neutron-activation analysis, 14MeV, reactor thermal, and reactor epithermal, are compared for the analysis of granites form the Bushveld Complex. A total of 34 elements can be determined in the granites by these methods. Samples from the Zaaiplaats area were analysed by thermal neutron activation, and 22 elements were determined in all of them. These elements were used to distinguish between the mineralized Bobbejaankop and Lease granites and the Main granite by the use of multivariate statistics. The Bobbejaankop granite appears as a more-differentaited rock carrying greater amounts of the incompatible elements than does the Main granite [af

  4. Propagation of epithermal neutrons in the empty mesh of the EDF3 reactor. Application of Zeus IV

    International Nuclear Information System (INIS)

    Brisbois, Jacques; Sonnet, Alain; Rafalovitch, Armand

    1969-10-01

    The authors report the verification of the Zeus 4 Monte Carlo code by applying it to an actual example of neutron propagation in a large enclosure, the empty mesh of the EDF3 reactor, supplied through the box holes (for the passage of heat transfer fluid ducts). This enclosure is represented by 105 parallelepipedic meshes in which are placed 4 plane and square sources of same cross section as the holes, and emitting inwards in cos θ. Source intensity is determined by flow rate measurements during tests in the air, interpreted by a Zeus-based calculation and channel power measurements during a 387 MW level operation. The presence of ducts is taken into account by applying a global attenuation coefficient to the sources. Calculation and experiment results agree very well in view of geometry complexity [fr

  5. Reference neutron activation library

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-04-01

    Many scientific endeavors require accurate nuclear data. Examples include studies of environmental protection connected with the running of a nuclear installation, the conceptual designs of fusion energy producing devices, astrophysics and the production of medical isotopes. In response to this need, many national and international data libraries have evolved over the years. Initially nuclear data work concentrated on materials relevant to the commercial power industry which is based on the fission of actinides, but recently the topic of activation has become of increasing importance. Activation of materials occurs in fission devices, but is generally overshadowed by the primary fission process. In fusion devices, high energy (14 MeV) neutrons produced in the D-T fusion reaction cause activation of the structure, and (with the exception of the tritium fuel) is the dominant source of activity. Astrophysics requires cross-sections (generally describing neutron capture) or its studies of nucleosynthesis. Many analytical techniques require activation analysis. For example, borehole logging uses the detection of gamma rays from irradiated materials to determine the various components of rocks. To provide data for these applications, various specialized data libraries have been produced. The most comprehensive of these have been developed for fusion studies, since it has been appreciated that impurities are of the greatest importance in determining the overall activity, and thus data on all elements are required. These libraries contain information on a wide range of reactions: (n,{gamma}), (n,2n), (n,{alpha}), (n,p), (n,d), (n,t), (n,{sup 3}He)and (n,n')over the energy range from 10{sup -5} eV to 15 or 20 MeV. It should be noted that the production of various isomeric states have to be treated in detail in these libraries,and that the range of targets must include long-lived radioactive nuclides in addition to stable nuclides. These comprehensive libraries thus contain

  6. Reference neutron activation library

    International Nuclear Information System (INIS)

    2002-04-01

    Many scientific endeavors require accurate nuclear data. Examples include studies of environmental protection connected with the running of a nuclear installation, the conceptual designs of fusion energy producing devices, astrophysics and the production of medical isotopes. In response to this need, many national and international data libraries have evolved over the years. Initially nuclear data work concentrated on materials relevant to the commercial power industry which is based on the fission of actinides, but recently the topic of activation has become of increasing importance. Activation of materials occurs in fission devices, but is generally overshadowed by the primary fission process. In fusion devices, high energy (14 MeV) neutrons produced in the D-T fusion reaction cause activation of the structure, and (with the exception of the tritium fuel) is the dominant source of activity. Astrophysics requires cross-sections (generally describing neutron capture) or its studies of nucleosynthesis. Many analytical techniques require activation analysis. For example, borehole logging uses the detection of gamma rays from irradiated materials to determine the various components of rocks. To provide data for these applications, various specialized data libraries have been produced. The most comprehensive of these have been developed for fusion studies, since it has been appreciated that impurities are of the greatest importance in determining the overall activity, and thus data on all elements are required. These libraries contain information on a wide range of reactions: (n,γ), (n,2n), (n,α), (n,p), (n,d), (n,t), (n, 3 He)and (n,n')over the energy range from 10 -5 eV to 15 or 20 MeV. It should be noted that the production of various isomeric states have to be treated in detail in these libraries,and that the range of targets must include long-lived radioactive nuclides in addition to stable nuclides. These comprehensive libraries thus contain almost all the

  7. Utilization and facility of neutron activation analysis in HANARO research reactor

    International Nuclear Information System (INIS)

    Chung, Y.S.; Chung, Y.J.; Moon, J.H.

    1998-01-01

    The facilities of neutron activation analysis within a multi-purpose research reactor (HANARO) are described and the main applications of Neutron activation analysis (NAA) in Korea are reviewed. The sample irradiation tube, automatic and manual pneumatic transfer system, are installed at three irradiation holes. One irradiation hole is lined with a cadmium tube for epithermal-nal NAA. The performance of the NAA facility was examined to identify the characteristics of tube transfer system, irradiation sites and polyethylene irradiation capsule. The available thermal neutron flux with each irradiation site are in the range of 3.9x10 13 -1.6x10 14 n/cm 2 ·s and cadmium ratios are 15-250. Neutron activation analysis has been applied in the trace component analysis of nuclear, geological, biological, environmental and high purity materials and various polymers for research and development. Analytical services and the latest analytical results are summarized. (author)

  8. Utilization and facility of neutron activation analysis in HANARO research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Y S; Chung, Y J; Moon, J H [Korea Atomic Energy Research Institute, P.O.Box 105 Yusong, 305-600, Taejon (Korea, Republic of)

    1998-07-01

    The facilities of neutron activation analysis within a multi-purpose research reactor (HANARO) are described and the main applications of Neutron activation analysis (NAA) in Korea are reviewed. The sample irradiation tube, automatic and manual pneumatic transfer system, are installed at three irradiation holes. One irradiation hole is lined with a cadmium tube for epithermal-nal NAA. The performance of the NAA facility was examined to identify the characteristics of tube transfer system, irradiation sites and polyethylene irradiation capsule. The available thermal neutron flux with each irradiation site are in the range of 3.9x10{sup 13}-1.6x10{sup 14} n/cm{sup 2}{center_dot}s and cadmium ratios are 15-250. Neutron activation analysis has been applied in the trace component analysis of nuclear, geological, biological, environmental and high purity materials and various polymers for research and development. Analytical services and the latest analytical results are summarized. (author)

  9. Neutron activation analysis

    International Nuclear Information System (INIS)

    Okada, Yukiko

    2005-01-01

    Trends and progress in neutron activation analysis (NAA) for the period starting in 1999 to 2003 are presented. Numbers of published reports on NAA are decreasing year by year as investigated from the database JST and NUCLEN. Summary reports on the international conferences held on NAA are followed by classifying according to the fields: various measurement techniques and application fields. Specially focused topics are newly developed techniques for measuring trace elements with high sensitivity and high accuracy such as (1) by diminishing the Compton-background gamma-rays using anti-coincidence technique, (2) by using prompt-gamma rays measurement method (PGAA) and (3) by using a gamma-ray detector array (GEMINI), which has succeeded in a simultaneous quantification of 27 elements from a standard rock sample having a weight of only 10 milligrams, and others. These techniques will be applied in the space and earth sciences and medical fields. (S. Ohno)

  10. Different methodologies in neutron activation to approach the full analysis of environmental and nutritional samples

    International Nuclear Information System (INIS)

    Freitas, M.C.; Dionisio, I.; Dung, H.M.

    2008-01-01

    Different methodologies of neutron activation analysis (NAA) are now available at the Technological and Nuclear Institute (Sacavem, Portugal), namely Compton suppression, epithermal activation, replicate and cyclic activation, and low energy photon measurement. Prompt gamma activation analysis (PGAA) will be implemented soon. Results by instrumental NAA and PGAA on environmental and nutritional samples are discussed herein, showing that PGAA - carried out at the Institute of Isotope Research (Budapest, Hungary) - brings about an effective input to assessing relevant elements. Sensitivity enhancement in NAA by Compton suppression is also illustrated. Through a judicious combination of methodologies, practically all elements of interest in pollution and nutrition terms can be determined. (author)

  11. The monostandard method in thermal neutron activation analysis of geological, biological and environmental materials

    International Nuclear Information System (INIS)

    Alian, A.; Djingova, R.G.; Kroener, B.; Sansoni, B.

    1984-01-01

    A simple method is described for instrumental multielement thermal neutron activation analysis using a monostandard. For geological and air dust samples, iron is used as a comparator, while sodium has advantages for biological materials. To test the capabilities of this method, the values of the effective cross sections of the 23 elements determined were evaluated in a reactor site with an almost pure thermal neutron flux of about 9x10 12 nxcm -2 xs -1 and an epithermal neutron contribution of less than 0.03%. The values obtained were found to agree mostly well with the best literature values of thermal neutron cross sections. The results of an analysis by activation in the same site agree well with the relative method using multielement standards and for several standard reference materials with certified element contents. A comparison of the element contents obtained by the monostandard and relative methods together with corresponding precisions and accuracies is given. (orig.) [de

  12. Modern Trends in Neutron Activation Analysis. Applications to some African Environmental Samples

    International Nuclear Information System (INIS)

    Hassan, A.M.

    2009-01-01

    This review covers the results of several published articles which deal with the modern trends in neutron activation analysis techniques using some of African research reactors for some environmental samples. The samples used have been collected from different areas in Egypt, South Africa, Ghana, Morocco, Nigeria, and Algeria. The neutron irradiation facilities and the advanced detection systems in each country are outlined. The prompt and delayed gamma-rays emitted due to neutron capture have been applied for investigation of the elemental constituents of such samples. Covered applications include exploration, mining, industrial environment, pollution of air, foodstuffs, soils and irrigation water samples. Some of the developed software programmes as well as the modern methods of data analysis are presented. The thermal and epithermal neutron activation analysis techniques have been applied for estimation of major, minor and trace elements in each material. Some of these data are presented with several comments.

  13. Neutron activation analysis methodology of marine sediments of the Cuban shelf

    International Nuclear Information System (INIS)

    Garcia, G.

    1988-01-01

    It is described the methodology followed for the neutron activation analysis of marine sediments of the Cuban shelf. A total of 35 elements were determined by means of the employment of thermal and epithermal fluxes of a nuclear reactor as well as from the flux of a generator of 14 MeV neutrons. It is signaled the particularities of detection and measurement of some elements and their interferences, with and special mention of the correction over 153 Sm, 113m In(Sn), 65 Zn, 160 Th, 169 Yb, 75 Sc and 177 Lu. It is concluded that 82% of elements may be determined with epithermal neutrons and 41%, with thermal neutrons. Only Si is determined with 14 MeV neutrons. Moreover, it is recommended the optimal periods of decaying (''cooling'') by groups of elements. The determined elements were: Ag, As, Au, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Mo, Na, Nd, Ni, Rb, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Th, U, W, Yb, Zn and Zr. The accuracy varied between 1% and 5% to 19 elements, between 6% and 10% to 5 elements, between 11% and 30% to 6 elements and it was greater than 30% to 5 elements

  14. Reactor neutron activation for multielemental analysis

    International Nuclear Information System (INIS)

    Reddy, A.V.R.

    1999-01-01

    Neutron Activation Analysis using single comparator (K 0 NAA method) has been used for obtaining multielemental profiles in a variety of matrices related to environment. Gold was used as the comparator. Neutron flux was characterised by determining f, the epithermal to thermal neutron flux ratio and cc, the deviation from ideal shape of the neutron spectrum. The f and a were determined in different irradiation positions in APSARA reactor, PCF position in CIRUS reactor and tray rod position in Dhruva reactor using both cadmium cut off and multi isotope detector methods. High resolution gamma ray spectrometry was used for radioactive assay of the activation products. This technique is being used for multielement analysis in a variety of matrices like lake sediments, sea nodules and crusts, minerals, leaves, cereals, pulses, leaves, water and soil. Elemental profiles of the sediments corresponding to different depths from Nainital lake were determined and used to understand the history of natural absorption/desorption pattern of the previous 160 years. Ferromanganese crusts from different locations of Indian Ocean were analysed with a view to studying the distribution of some trace elements along with Fe and Mn. Variation of Mn/Fe ratio was used to identify the nature of the crusts as hydrogenous or hydrothermal. Fe-rich and Fe-depleted nodules from Indian Ocean were analysed to understand the REE patterns and it is proposed that REE-Th associated minerals could be the potential Th contributors to the sea water and thus reached ferromanganese nodules. Dolomites (unaltered and altered), two types of serpentines and intrusive rock dolerite from the asbestos mines of Cuddapah basin were analysed for major, minor and trace elements. The elemental concentrations are used for distinguishing and characterising these minerals. From our investigations, it was concluded that both dolomite and dolerite contribute elements in the serpentinisation process. Chemical neutron

  15. A PC-program for the calculation of neutron flux and element contents using the ki-method of neutron activation analysis

    International Nuclear Information System (INIS)

    Boulyga, E.G.; Boulyga, S.F.

    2000-01-01

    A computer program is described, which calculates the induced activities of isotopes after irradiation in a known neutron field, thermal and epithermal neutron fluxes from the measured induced activities and from nuclear data of 2-4 monitor nuclides as well as the element concentrations in samples irradiated together with the monitors. The program was developed for operation in Windows 3.1 (or higher). The application of the program for neutron activation analysis allows to simplify the experimental procedure and to reduce the time. The program was tested by measuring different types of standard reference materials at the FRJ-2 (Research Centre, Juelich, Germany) and Triga (University Mainz, Germany) reactors. Comparison of neutron flux parameters calculated by this program with those calculated by a VAX program developed at the Research Centre, Juelich was done. The results of testing seem to be satisfactory. (author)

  16. A neutron activation analyzer

    International Nuclear Information System (INIS)

    Westphal, G.P.; Lemmel, H.; Grass, F.; De Regge, P.P.; Burns, K.; Markowicz, A.

    2005-01-01

    Dubbed 'Analyzer' because of its simplicity, a neutron activation analysis facility for short-lived isomeric transitions is based on a low-cost rabbit system and an adaptive digital filter which are controlled by a software performing irradiation control, loss-free gamma-spectrometry, spectra evaluation, nuclide identification and calculation of concentrations in a fully automatic flow of operations. Designed for TRIGA reactors and constructed from inexpensive plastic tubing and an aluminum in-core part, the rabbit system features samples of 5 ml and 10 ml with sample separation at 150 ms and 200 ms transport time or 25 ml samples without separation at a transport time of 300 ms. By automatically adapting shaping times to pulse intervals the preloaded digital filter gives best throughput at best resolution up to input counting rates of 10 6 cps. Loss-free counting enables quantitative correction of counting losses of up to 99%. As a test of system reproducibility in sample separation geometry, K, Cl, Mn, Mg, Ca, Sc, and V have been determined in various reference materials at excellent agreement with consensus values. (author)

  17. Boron neutron capture therapy using mixed epithermal and thermal neutron beams in patients with malignant glioma-correlation between radiation dose and radiation injury and clinical outcome

    International Nuclear Information System (INIS)

    Kageji, Teruyoshi; Nagahiro, Shinji; Matsuzaki, Kazuhito; Mizobuchi, Yoshifumi; Toi, Hiroyuki; Nakagawa, Yoshinobu; Kumada, Hiroaki

    2006-01-01

    Purpose: To clarify the correlation between the radiation dose and clinical outcome of sodium borocaptate-based intraoperative boron neutron capture therapy in patients with malignant glioma. Methods and Materials: The first protocol (P1998, n = 8) prescribed a maximal gross tumor volume (GTV) dose of 15 Gy. In 2001, a dose-escalated protocol was introduced (P2001, n 11), which prescribed a maximal vascular volume dose of 15 Gy or, alternatively, a clinical target volume (CTV) dose of 18 Gy. Results: The GTV and CTV doses in P2001 were 1.1-1.3 times greater than those in P1998. The maximal vascular volume dose of those with acute radiation injury was 15.8 Gy. The mean GTV and CTV dose in long-term survivors with glioblastoma was 26.4 and 16.5 Gy, respectively. A statistically significant correlation between the GTV dose and median survival time was found. In the 11 glioblastoma patients in P2001, the median survival time was 19.5 months and 1- and 2-year survival rate was 60.6% and 37.9%, respectively. Conclusion: Dose escalation contributed to the improvement in clinical outcome. To avoid radiation injury, the maximal vascular volume dose should be <12 Gy. For long-term survival in patients with glioblastoma after boron neutron capture therapy, the optimal mean dose of the GTV and CTV was 26 and 16 Gy, respectively

  18. Evaluation of radioactivity in the bodies of mice induced by neutron exposure from an epi-thermal neutron source of an accelerator-based boron neutron capture therapy system

    Science.gov (United States)

    NAKAMURA, Satoshi; IMAMICHI, Shoji; MASUMOTO, Kazuyoshi; ITO, Masashi; WAKITA, Akihisa; OKAMOTO, Hiroyuki; NISHIOKA, Shie; IIJIMA, Kotaro; KOBAYASHI, Kazuma; ABE, Yoshihisa; IGAKI, Hiroshi; KURITA, Kazuyoshi; NISHIO, Teiji; MASUTANI, Mitsuko; ITAMI, Jun

    2017-01-01

    This study aimed to evaluate the residual radioactivity in mice induced by neutron irradiation with an accelerator-based boron neutron capture therapy (BNCT) system using a solid Li target. The radionuclides and their activities were evaluated using a high-purity germanium (HP-Ge) detector. The saturated radioactivity of the irradiated mouse was estimated to assess the radiation protection needs for using the accelerator-based BNCT system. 24Na, 38Cl, 80mBr, 82Br, 56Mn, and 42K were identified, and their saturated radioactivities were (1.4 ± 0.1) × 102, (2.2 ± 0.1) × 101, (3.4 ± 0.4) × 102, 2.8 ± 0.1, 8.0 ± 0.1, and (3.8 ± 0.1) × 101 Bq/g/mA, respectively. The 24Na activation rate at a given neutron fluence was found to be consistent with the value reported from nuclear-reactor-based BNCT experiments. The induced activity of each nuclide can be estimated by entering the saturated activity of each nuclide, sample mass, irradiation time, and proton current into the derived activation equation in our accelerator-based BNCT system. PMID:29225308

  19. Neutron activation analysis

    International Nuclear Information System (INIS)

    Borsaru, M.; Eisler, P.L.

    1981-01-01

    A method of simultaneously analysing the aluminium and silicon content of a sample of material is claimed. The method comprises the following steps: (1) irradiating the sample with fast neutrons; (2) monitoring the thermal neutron flux within the sample; (3) monitoring the gamma radiation from the irradiated sample at energies of 1.78 MeV and 1.015 and/or 0.844 MeV; (4) using the monitored gamma radiation at 1.015 and/or 0.844 MeV to estimate the aluminium content of the sample; and (5) using the monitored gamma radiation at 1.78 MeV, compensated by the gamma radiation at 1.78 MeV due to the thermal neutron reaction with the estimated aluminium in the sample to estimate the silicon content

  20. Fast-neutron activation analysis of manganese nodules

    International Nuclear Information System (INIS)

    Michaelis, W.; Fanger, H.U.; Mueller, A.; Pepelnik, R.

    1976-01-01

    The present paper describes the development of a new nuclear method that allows rapid determinations of the most relevant metals Ni and Cu without sample treatment, thus being particularly suited for quasi-continuous elemental analyses in mining and processing. The measurement is based on fast-neutron activation using Cockcroft-Walton generators, sealed neutron tubes or, possibly, (α,n)-type natural sources. Fast-neutron activation of manganese nodules is dominated by the (n,p)-reactions on Si, Al, Fe; the (n,α)-reaction on Mn and the (n,2n)-reaction on Cu. By choosing appropriate irradiation and cooling periods gamma-ray activities with comparatively simple spectral distributions are induced. From these spectra the Mn/Fe ratio in the nodules can be determined without the elaborate procedures usually required in absolute methods for eliminating systematic errors from fluctuations in sample and/or irradiation parameters. It is connected with the absolute Ni and Cu contents via well-known geochemical correlations which according to a lot of statistical data apply to quite different deposits and nodule types in the Pacific. Using these correlations the determination of the most important metals reduces to the evaluation of a peak area ratio. Measurements of the neutron flux distribution and the apparent sample density are unnecessary. The simple structure of the spectra allows the application of detectors with modest energy resolution, e.g. scintillation counters which can be manufactured as ruggedized crystal assemblies with great resistance to thermal and mechanical shock. The method is described in detail and possible interference, in particular from thermal and epithermal neutrons, are discussed. (orig.) [de

  1. Trace elements in 11 fruits widely-consumed in the USA as determined by neutron activation analysis

    International Nuclear Information System (INIS)

    Michenaud-Rague, A.; Robinson, S.; Landsberger, S.

    2012-01-01

    While there is a lot of information on the elemental content of food for nutritional and pollution studies, the analysis of fruits has received little attention. We have investigated 11 commonly eaten fruits for their trace and minor element constituents by neutron activations including thermal and epithermal neutron activation analysis. Our results revealed that both blueberries and strawberries had the most of top two highest elemental concentrations followed by raspberries, oranges and mango. Bananas, grapes, plums, apples, pears, and cherries had the fewest or none of the most elevated elemental concentrations. (author)

  2. Enhanced NIF neutron activation diagnostics.

    Science.gov (United States)

    Yeamans, C B; Bleuel, D L; Bernstein, L A

    2012-10-01

    The NIF neutron activation diagnostic suite relies on removable activation samples, leading to operational inefficiencies and a fundamental lower limit on the half-life of the activated product that can be observed. A neutron diagnostic system measuring activation of permanently installed samples could remove these limitations and significantly enhance overall neutron diagnostic capabilities. The physics and engineering aspects of two proposed systems are considered: one measuring the (89)Zr/(89 m)Zr isomer ratio in the existing Zr activation medium and the other using potassium zirconate as the activation medium. Both proposed systems could improve the signal-to-noise ratio of the current system by at least a factor of 5 and would allow independent measurement of fusion core velocity and fuel areal density.

  3. Measurements of neutron flux in the RA reactor

    International Nuclear Information System (INIS)

    Raisic, N.

    1961-12-01

    This report includes the following separate parts: Thermal neutron flux in the experimental channels od RA reactor; Epithermal neutron flux in the experimental channels od RA reactor; Fast neutron flux in the experimental channels od RA reactor; Thermal neutron flux in the thermal column and biological experimental channel; Neutronic measurements in the RA reactor cell; Temperature reactivity coefficient of the RA reactor; design of the device for measuring the activity of wire [sr

  4. Pulsed neutron generator for use with pulsed neutron activation techniques

    International Nuclear Information System (INIS)

    Rochau, G.E.

    1980-01-01

    A high-output, transportable, pulsed neutron generator has been developed by Sandia National Laboratories for use with Pulsed Neutron Activation (PNA) techniques. The PNA neutron generator generates > 10 10 14 MeV D-T neutrons in a 1.2 millisecond pulse. Each operation of the unit will produce a nominal total neutron output of 1.2 x 10 10 neutrons. The generator has been designed to be easily repaired and modified. The unit requires no additional equipment for operation or measurement of output

  5. Neutron activation analysis for development of mercury sorbent based on blue-green alga salipriina palatinates

    International Nuclear Information System (INIS)

    Frontasyeva, M.V.; Kirkesali, E.I.; Aksenova, N.G.; Mosulishvili, L.M.; Belokobylsky, A.I.; Khizanishvili, A.I.

    2005-01-01

    Epithermal neutron activation analysis was used to study interaction of blue-green alga Spirulina platensis with toxic metal mercury. Various concentrations of Hg(II) were added to cell cultures in a nutrient medium. The dynamic of accumulation of Hg was investigated over days in relation to Spirulina biomass growth. The process of Hg adsorption by Spirulina biomass was studied in short-time experiments. The isotherm of adsorption was / out in Freindlich coordinates. Natural Spirulina biomass has potential to be used in the remediation of sewage waters at Hg concentrations ∼ 100 μg/1

  6. Calculations of neutron spectra after neutron-neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, B E [Gettysburg College, Box 405, Gettysburg, PA 17325 (United States); Stephenson, S L [Gettysburg College, Box 405, Gettysburg, PA 17325 (United States); Howell, C R [Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Mitchell, G E [North Carolina State University, Raleigh, NC 27695-8202 (United States); Tornow, W [Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Furman, W I [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Lychagin, E V [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Muzichka, A Yu [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Nekhaev, G V [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Strelkov, A V [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Sharapov, E I [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Shvetsov, V N [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)

    2004-09-01

    A direct neutron-neutron scattering length, a{sub nn}, measurement with the goal of 3% accuracy (0.5 fm) is under preparation at the aperiodic pulsed reactor YAGUAR. A direct measurement of a{sub nn} will not only help resolve conflicting results of a{sub nn} by indirect means, but also in comparison to the proton-proton scattering length, a{sub pp}, shed light on the charge-symmetry of the nuclear force. We discuss in detail the analysis of the nn-scattering data in terms of a simple analytical expression. We also discuss calibration measurements using the time-of-flight spectra of neutrons scattered on He and Ar gases and the neutron activation technique. In particular, we calculate the neutron velocity and time-of-flight spectra after scattering neutrons on neutrons and after scattering neutrons on He and Ar atoms for the proposed experimental geometry, using a realistic neutron flux spectrum-Maxwellian plus epithermal tail. The shape of the neutron spectrum after scattering is appreciably different from the initial spectrum, due to collisions between thermal-thermal and thermal-epithermal neutrons. At the same time, the integral over the Maxwellian part of the realistic scattering spectrum differs by only about 6 per cent from that of a pure Maxwellian nn-scattering spectrum.

  7. Determination of iodine in Asian diets by epithermal and radiochemical neutron activation analysis

    Czech Academy of Sciences Publication Activity Database

    Kučera, Jan; Iyengar, GV.; Řanda, Zdeněk; Parr, RM.

    2004-01-01

    Roč. 259, č. 3 (2004), s. 505-509 ISSN 0236-5731 R&D Projects: GA AV ČR IAA4048301 Institutional research plan: CEZ:AV0Z1048901 Keywords : iodine * Asian diets Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.457, year: 2004

  8. Epithermal neutron activation analysis investigation of Clarion-Clipperton abyssal plane clay and polymetallic micronodules.

    Science.gov (United States)

    Duliu, O G; Cristache, C I; Culicovc, O A; Frontasyeva, M V; Szobotca, S A; Toma, M

    2009-05-01

    The content of seven major (Na, Al, Cl, Mn, K, Ca, Ti, Fe) and 30 trace (Sc, V, Cr, Ni, Co, Zn, Cu, As, Sr, Rb, Zr, Mo, Sn, In, Sb, Ba, Cs, La, Ce, Nd, Eu, Sm, Tb, Dy, Yb, Hf, Ta, W, Th, U) elements determined by INAA in 13 samples of abyssal clay and two samples of micronodules collected from the North pacific Ocean Clarion-Clipperton abyssal plane is presented and discussed with respect to some rocks models.

  9. Epithermal neutron activation analysis investigation of Clarion-Clipperton abyssal plane clay and polymetallic micronodules

    International Nuclear Information System (INIS)

    Duliu, O.G.; Cristache, C.I.; Culicovc, O.A.; Frontasyeva, M.V.; Szobotca, S.A.; Toma, M.

    2009-01-01

    The content of seven major (Na, Al, Cl, Mn, K, Ca, Ti, Fe) and 30 trace (Sc, V, Cr, Ni, Co, Zn, Cu, As, Sr, Rb, Zr, Mo, Sn, In, Sb, Ba, Cs, La, Ce, Nd, Eu, Sm, Tb, Dy, Yb, Hf, Ta, W, Th, U) elements determined by INAA in 13 samples of abyssal clay and two samples of micronodules collected from the North pacific Ocean Clarion-Clipperton abyssal plane is presented and discussed with respect to some rocks models.

  10. Epithermal neutron activation analysis investigation of Clarion-Clipperton abyssal plane clay and polymetallic micronodules

    Energy Technology Data Exchange (ETDEWEB)

    Duliu, O.G. [University of Bucharest, Department of Atomic and Nuclear Physics, P.O. Box MG-11, 077125 Magurele, Ilfov (Romania)], E-mail: duliu@b.astral.ro; Cristache, C.I. [National Institute of Research and Development for Physics and Nuclear Engineering ' Horia-Hulubei' , P.O. Box MG-6, 077125 Magurele, Ilfov (Romania)], E-mail: ocarmen@ifin.nipne.ro; Culicovc, O.A. [Joint Institute of Nuclear Research, 6, Joliot Curie str., 141980 Dubna (Russian Federation)], E-mail: otilia_culicov@yahoo.com; Frontasyeva, M.V. [Joint Institute of Nuclear Research, 6, Joliot Curie str., 141980 Dubna (Russian Federation)], E-mail: marina@nf.jinr.ru; Szobotca, S.A. [National Institute of Geoecology and Marine Geology, 34 Dimitrie Onciul str., 024504 Bucharest (Romania)], E-mail: szobi@geoecomar.ro; Toma, M. [National Institute of Research and Development for Physics and Nuclear Engineering ' Horia-Hulubei' , P.O. Box MG-6, 077125 Magurele, Ilfov (Romania)

    2009-05-15

    The content of seven major (Na, Al, Cl, Mn, K, Ca, Ti, Fe) and 30 trace (Sc, V, Cr, Ni, Co, Zn, Cu, As, Sr, Rb, Zr, Mo, Sn, In, Sb, Ba, Cs, La, Ce, Nd, Eu, Sm, Tb, Dy, Yb, Hf, Ta, W, Th, U) elements determined by INAA in 13 samples of abyssal clay and two samples of micronodules collected from the North pacific Ocean Clarion-Clipperton abyssal plane is presented and discussed with respect to some rocks models.

  11. Accuracy estimation for intermediate and low energy neutron transport calculation with Monte Carlo code MCNP

    International Nuclear Information System (INIS)

    Kotegawa, Hiroshi; Sasamoto, Nobuo; Tanaka, Shun-ichi

    1987-02-01

    Both ''measured radioactive inventory due to neutron activation in the shield concrete of JPDR'' and ''measured intermediate and low energy neutron spectra penetrating through a graphite sphere'' are analyzed using a continuous energy model Monte Carlo code MCNP so as to estimate calculational accuracy of the code for neutron transport in thermal and epithermal energy regions. Analyses reveal that MCNP calculates thermal neutron spectra fairly accurately, while it apparently over-estimates epithermal neutron spectra (of approximate 1/E distribution) as compared with the measurements. (author)

  12. Analysis and databasing software for integrated tomographic gamma scanner (TGS) and passive-active neutron (PAN) assay systems

    International Nuclear Information System (INIS)

    Estep, R.J.; Melton, S.G.; Buenafe, C.

    2000-01-01

    The CTEN-FIT program, written for Windows 9x/NT in C++,performs databasing and analysis of combined thermal/epithermal neutron (CTEN) passive and active neutron assay data and integrates that with isotopics results and gamma-ray data from methods such as tomographic gamma scanning (TGS). The binary database is reflected in a companion Excel database that allows extensive customization via Visual Basic for Applications macros. Automated analysis options make the analysis of the data transparent to the assay system operator. Various record browsers and information displays simplify record keeping tasks

  13. Initial Experimental Verification of the Neutron Beam Modeling for the LBNL BNCT Facility

    International Nuclear Information System (INIS)

    Bleuel, D.L.; Chu, W.T.; Donahue, R.J.; Ludewigt, B.A.; McDonald, R.J.; Smith, A.R.; Stone, N.A.; Vuji, J.

    1999-01-01

    In preparation for future clinical BNCT trials, neutron production via the 7Li(p,n) reaction as well as subsequent moderation to produce epithermal neutrons have been studied. Proper design of a moderator and filter assembly is crucial in producing an optimal epithermal neutron spectrum for brain tumor treatments. Based on in-phantom figures-of-merit,desirable assemblies have been identified. Experiments were performed at the Lawrence Berkeley National Laboratory's 88-inch cyclotron to characterize epithermal neutron beams created using several microampere of 2.5 MeV protons on a lithium target. The neutron moderating assembly consisted of Al/AlF3 and Teflon, with a lead reflector to produce an epithermal spectrum strongly peaked at 10-20 keV. The thermal neutron fluence was measured as a function of depth in a cubic lucite head phantom by neutron activation in gold foils. Portions of the neutron spectrum were measured by in-air activation of six cadmium-covered materials (Au, Mn, In, Cu, Co, W) with high epithermal neutron absorption resonances. The results are reasonably reproduced in Monte Carlo computational models, confirming their validity

  14. Pulsed neutron activation calibration technique

    International Nuclear Information System (INIS)

    Kehler, P.

    1979-01-01

    A pulsed neutron activation (PNA) for measurement of two-phase flow consists of a pulsed source of fast neutron to activate the oxygen in a steam-water mixture. Flow is measured downstream by an NaI detector. Measured counts are sorted by a multiscaler into different time channels. A counts vs. time distribution typical for two-phase flow with slip between the two phases is obtained. Proper evaluation for the counts/time distribution leads to flow-regime independent equations for the average of the inverse transil time and the average density. After calculation of the average mass flow velocity, the true mass flow is derived

  15. Prompt gamma neutron activation analysis

    International Nuclear Information System (INIS)

    Goswami, A.

    2003-01-01

    Prompt gamma neutron activation analysis (PGNAA) is a technique for the analysis of elements present in solid, liquid and gaseous samples by measuring the capture gamma rays emitted from the sample during neutron irradiation. The technique is complementary to conventional neutron activation analysis (NAA) as it can be used in number of cases where NAA fails. Though the technique was first used in sixties, the advantage of the technique was first highlighted by Lindstrom and Anderson. PGNAA is increasingly being used as a rapid, instrumental, nondestructive and multielement analysis technique. A monograph and several excellent reviews on this topic have appeared recently. In this review, an attempt has been made to bring out the essential aspects of the technique, experimental arrangement and instrumentation involved, and areas of application. Some of the results will also be presented

  16. Application of neutron activation analysis

    International Nuclear Information System (INIS)

    Dybczynski, R.

    2001-01-01

    The physical basis and analytical possibilities of neutron activation analysis have been performed. The number of applications in material engineering, geology, cosmology, oncology, criminology, biology, agriculture, environment protection, archaeology, history of art and especially in chemical analysis have been presented. The place of the method among other methods of inorganic quantitative chemical analysis for trace elements determination has been discussed

  17. Multiple episodes of hydrothermal activity and epithermal mineralization in the southwestern Nevada volcanic field and their relations to magmatic activity, volcanism and regional extension

    International Nuclear Information System (INIS)

    Weiss, S.I.; Noble, D.C.; Jackson, M.C.

    1994-01-01

    Volcanic rocks of middle Miocene age and underlying pre-Mesozoic sedimentary rocks host widely distributed zones of hydrothermal alteration and epithermal precious metal, fluorite and mercury deposits within and peripheral to major volcanic and intrusive centers of the southwestern Nevada volcanic field (SWNVF) in southern Nevada, near the southwestern margin of the Great Basin of the western United States. Radiometric ages indicate that episodes of hydrothermal activity mainly coincided with and closely followed major magmatic pulses during the development of the field and together spanned more than 4.5 m.y. Rocks of the SWNVF consist largely of rhyolitic ash-flow sheets and intercalated silicic lava domes, flows and near-vent pyroclastic deposits erupted between 15.2 and 10 Ma from vent areas in the vicinity of the Timber Mountain calderas, and between about 9.5 and 7 Ma from the outlying Black Mountain and Stonewall Mountain centers. Three magmatic stages can be recognized: the main magmatic stage, Mountain magmatic stage (11.7 to 10.0 Ma), and the late magmatic stage (9.4 to 7.5 Ma)

  18. Neutron activation analysis in Bulgaria

    International Nuclear Information System (INIS)

    Apostolov, D.

    1985-01-01

    The development of instrumental neutron activation analysis (INAA) as a routine method started in 1960 with bringing into use of the experimental nuclear reactor 2 MW -IRT-2000. For the purposes of INAA the vertical channels were used. The neutron flux vary from 1 to 6x10 12 n/cm 2 s, with Cd ratio for gold of about 4,4. In one of the channels the neutron flux is additionally thermalised with grafite, in others - a pneumatic double-tube rabbit system is installed. One of the irradiation positions is equiped with 1 mm Cd shield constantly. With the pressure of the working gas (air) of 2 bar the transport time in one direction is 2,5 sec. Because of lack of special system for uniform irradiation an accuracy of 3% can be reached by use of iron monitors for long irradiations and copper monitors for use in the rabbit system. Two neutron generators are also working but the application of 14 MeV neutrons for INAA is still quite limited. The most developed are the applications of INAA in the fields of geology and paedology, medicine and biology, environment and pollution, archaeology, metallurgy, metrology and hydrology, criminology

  19. Different Activation Techniques for the Study of Epithermal Spectra, Applied to Heavy Water Lattices of Varying Fuel-To-Moderator Ratio

    Energy Technology Data Exchange (ETDEWEB)

    Sokolowski, E K

    1966-06-15

    Spectral indices at the cell boundary have been studied as functions of lattice pitch in the reference core of the Swedish R0 reactor. Epithermal indices were determined by activation of In{sup 115}, employing three different techniques: the two-foil, the cadmium ratio and the sandwich foil methods. The latter of these has the advantage of being independent of assumptions about foil cross sections or spectral functions, and it gives a spectrum index that lends itself readily to comparisons with theoretical multigroup calculations. Alternatively the results can be expressed in terms of the Westcott parameters r and T{sub n} when this is justified by the spectral conditions. The agreement between the three methods investigated is generally good. Good agreement is also found with multigroup collision.

  20. Activation analysis with reactor neutrons

    International Nuclear Information System (INIS)

    Gangadharan, S.

    1983-01-01

    The potentialities of neutron as an analytical probe are indicated, pointing out the need for development of other approaches, besides the conventional activation method. Development of instrumental approach to activation and applications, carried out at Analytical Chemistry Division are outlined. The role of, and the need for, the development and application of mathematical methods in enhancing the information content, and in turn the interpretation of the analytical results, is demonstrated. (author)

  1. Generating energy dependent neutron flux maps for effective ...

    African Journals Online (AJOL)

    For activation analysis and irradiation scheme of miniature neutron source reactor, designers or engineers usually require information on thermal neutron flux levels and other energy group flux levels (such as fast, resonance and epithermal). A methodology for readily generating such flux maps and flux profiles for any ...

  2. Neutron activation analysis and atomic absorption spectrophotometry for the analysis of fresh, pasteurised and powder milk

    International Nuclear Information System (INIS)

    Wasim, M.; Rehman, S.; Arif, M.; Fatima, I.; Zaidi, J.H.

    2012-01-01

    This study shows the application of semi-absolute k 0 instrumental neutron activation analysis (k 0 -INAA), epithermal neutron activation analysis (ENAA) and atomic absorption spectrophotometry (AAS) for the determination of 21 elements (Br, Ca, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sc Sr, and Zn) in different types of milk samples. The ENAA was required for the determination of iodine, AAS for Cu, Ni and Pb and the rest of the elements were measured by k 0 -INAA. Thirteen elements (Br, Ca, Cl, Cs, Cu, Fe, K, Mg, Na, P, Rb, Sr and Zn) were identified in all milk samples. Ni was detected in eleven and Pb in two samples. Concentrations of most of the elements were within the ranges of the world reported data. The data was further explored by principal component analysis to find relationships between samples and elements. (orig.)

  3. Neutron activation spectrometry and neutron activation analysis in analytical geochemistry

    International Nuclear Information System (INIS)

    Dulski, P.; Moeller, P.

    1975-07-01

    The present report is to show the geochemists who are interested in neutron activation spectrometry (NAS) and neutron activation analysis (NAA) which analytical possibilities these methods offer him. As a review of these analytical possibilities, a lieterature compolation is given which is subdivided into two groups: 1) rock (basic, intermediary, acid, sediments, soils and nuds, diverse minerals, tectites, meteorites and lunar material). 2) ore (Al, Au, Be, Cr, Cu, Mn, Mo, Fe, Pb, Pt, Sn, Ti, W, Zn, Zr, U and phosphate ore, polymetallic ores, fluorite, monazite and diverse ores). The applied methods as well as the determinable elements in the given materials can be got from the tables. On the whole, the literature evaluation carried out makes it clear that neutron activation spectrometry is a very useful multi-element method for the analysis of rocks. The analysis of ores, however, is subjected to great limitations. As rock analysis is very frequently of importance in prospecting for ore deposits, the NAS proves to be extremely useful for this very field of application. (orig./LH) [de

  4. Characterization of the TRIGA Mark III reactor for k0-neutron activation analysis

    International Nuclear Information System (INIS)

    Diaz R, O.; Herrera P, E.; Lopez R, M.C.

    1997-01-01

    The non-ideality of the epithermal neutron flux distribution in a a reactor site parameter (α), the thermal-to-epithermal neutron ratio (f), the irradiation channel neutron temperature (T n ) and the k 0 -factors for more than 20 isotopes were determined in the 3 typical irradiation positions of the TRIGA Mark III reactor of the National Nuclear Research Institute, Salazar, Mexico, using different experimental methods with conventional and non-conventional monitors. This characterization is used in the k 0 -method of NAA, recently introduced at the Institute. (author). 21 refs., 3 figs., 5 tabs

  5. Neutron activation analysis of artefacts

    International Nuclear Information System (INIS)

    Mohd Suhaimi Hamzah; Shamsiah Abd Rahman

    2004-01-01

    The paper discussed the utilization of neutron activation analysis in this field. NAA, an analytical technique which analyzing the elements in the sample without any chemical treatment. It is sensitive and accurate. Archaeological objects i.e. ceramics, historical building materials, metals, etc can be analyze with this technique. The analysis results were presented in form of characterization of the artefacts in chemical profiles, which can present the information of the origin of the artefacts as well as it originality. (Author)

  6. Neutron Activation Analysis with k0-standardisation

    International Nuclear Information System (INIS)

    Pomme, S.

    2001-01-01

    SCK-CEN's programme on Neutron Activation Analysis with k 0 -standardisation concentrates on the improvement of the standardisation method and the characterisation of the neutron field as well as on the improvement of the statistical control on neutron activation analysis. Main achievements in 2000 are reported

  7. Use of Germanium as comparator and integral monitor of neutron flux in activation analysis

    International Nuclear Information System (INIS)

    Furnari, Juan C.; Cohen, Isaac M.; Arribere, Maria A.; Kestelman, Abraham J.

    1997-01-01

    The possibility of using germanium as monitor of the thermal and epithermal components of the neutron flux, and comparator in parametric activation analysis, is discussed. The advantages and drawbacks associated to the use of this element are commented on, and the comparison with zirconium, in terms of the determination relative error, is performed. The utilisation of germanium as integral flux monitor, including the fast component of the neutron spectrum, is also discussed. Data corresponding to measurements of k 0 factor for the most relevant gamma transitions from Ge-75 and Be-77 are presented, as well as the results of the reference material analysis, employing germanium as flux monitor and comparator in a simultaneous way. (author). 8 refs., 3 figs., 2 tabs

  8. Studies on application of radiation and radioisotopes -Studies on application of neutron activation analysis-

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yong Sam; Jung, Yung Joo; Jung, Eui Sik; Lee, Sang Mee [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kim, Nak Bae [Korea Institute of Geology, Mining and Materials, Taejon (Korea, Republic of)

    1995-07-01

    To apply Neutron activation analysis to routine analysis of environmental samples utilizing the research reactor (TRIGA MK-III), improving effects of analytical sensitivity have been investigated using both of thermal and epithermal neutron irradiating technique. Identification and development of analytical procedure was carried out using three kinds of standard reference materials (urban particulate matter, coal fly ash, soil). In addition, the confidence of this method was established by participation in collaborative research for the training and apply of international credit of analytical procedure. Practical studies on air dust samples have also been carried out regionally and seasonally. For the investigation on emission source of special element, enrichment factor was calculated in urban and rural area. Besides, a suitable process of biological sample (pine needle) analyses has been established by carrying out identification of uncertainty using standard reference material. The concentration of elements in practical samples were also determined regionally and seasonally. 14 figs, 26 tabs, 67 refs. (Author).

  9. Studies on application of radiation and radioisotopes -Studies on application of neutron activation analysis-

    International Nuclear Information System (INIS)

    Jung, Yong Sam; Jung, Yung Joo; Jung, Eui Sik; Lee, Sang Mee; Kim, Nak Bae

    1995-07-01

    To apply Neutron activation analysis to routine analysis of environmental samples utilizing the research reactor (TRIGA MK-III), improving effects of analytical sensitivity have been investigated using both of thermal and epithermal neutron irradiating technique. Identification and development of analytical procedure was carried out using three kinds of standard reference materials (urban particulate matter, coal fly ash, soil). In addition, the confidence of this method was established by participation in collaborative research for the training and apply of international credit of analytical procedure. Practical studies on air dust samples have also been carried out regionally and seasonally. For the investigation on emission source of special element, enrichment factor was calculated in urban and rural area. Besides, a suitable process of biological sample (pine needle) analyses has been established by carrying out identification of uncertainty using standard reference material. The concentration of elements in practical samples were also determined regionally and seasonally. 14 figs, 26 tabs, 67 refs. (Author)

  10. Determination of rare earths and traces of other elements by neutron activation analysis

    International Nuclear Information System (INIS)

    Atalla, L.T.; Mantovani, M.S.M.; Marques, L.S.

    A complete methodology for a multielemental analysis in geological material using the neutron activation technique was developed. 21 trace elements (9 of which are rare earths) were determined using thermal and epithermal neutron irradiations. Instrumetnal and radiochemical processing, applied to BCR-1 and G-2 geological standards, are described. Statistical tests carried out on G-2 data show an error smaller than 15% referring to all elements except Cr, Sb and Yb. The observed differences between are discussed. The good precision attained in this method is confirmed by its application to BCR-1 standard, which presents errors smaller than 4% for all elements except Nd, due to its intrinsic properties. The results from the present work are compared with those from other laboratories. (C.L.B.) [pt

  11. Pulsed neutron porosity logging system

    International Nuclear Information System (INIS)

    Smith, H.D. Jr.; Smith, M.P.; Schultz, W.E.

    1978-01-01

    An improved pulsed neutron porosity logging system is provided in the present invention. A logging tool provided with a 14 MeV pulsed neutron source, an epithermal neutron detector, and a fast neutron detector is moved through a borehole. Repetitive bursts of neutrons irradiate the earth formations and, during the bursts, the fast neutron population is sampled. During the interval between bursts the epithermal neutron population is sampled along with background gamma radiation due to lingering thermal neutrons. The fast and epithermal neutron population measurements are combined to provide a measurement of formation porosity

  12. Determination of trace gold in rocks and minerals by neutron activation analysis

    International Nuclear Information System (INIS)

    Zhao Yunlong; Zhou Suqing; Liang Yutang

    1988-05-01

    The determination of trace gold in rocks and minerals by neutron activation analysis is described. Two methods are used for pre-separating and concentrating the trace gold in geological samples. one of the methods is that the samples are dissolved in aqua regia solution; activated carbon paper pulp filter is used for pre-separating and concentrating trace gold by dynamic adsorption method; then the activated carbon containing gold was ashed at 650 ∼ 700 deg c. The other method is that the samples are dissolved in aqua regia solution; the polyurethane foam plastic filled with activated carbon is used for pre-separating and concentrating trace gold by dynamic adsorption method; then the foam plastic containing gold was ashed at 650 deg c. The gold in ashes is determinated by neutron activation analysis. The detection limit is 0.004ng/g. The accuracy of the method is examined by gold in reference standard material. The results of this method are in good agreement with the recommended value. For analysis of the trace gold by the methods of instrumental neutron activation analysis and epithermal neutron activation analysis, the interference of 411.8 keV γ-ray from 153 Sm, 152 Eu and fission products of uranium and the correction methods are discussed

  13. MANTA. An Integral Reactor Physics Experiment to Infer the Neutron Capture Cross Sections of Actinides and Fission Products in Fast and Epithermal Spectra

    Energy Technology Data Exchange (ETDEWEB)

    Youinou, Gilles Jean-Michel [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-10-01

    Neutron cross-sections characterize the way neutrons interact with matter. They are essential to most nuclear engineering projects and, even though theoretical progress has been made as far as the predictability of neutron cross-section models, measurements are still indispensable to meet tight design requirements for reduced uncertainties. Within the field of fission reactor technology, one can identify the following specializations that rely on the availability of accurate neutron cross-sections: (1) fission reactor design, (2) nuclear fuel cycles, (3) nuclear safety, (4) nuclear safeguards, (5) reactor monitoring and neutron fluence determination and (6) waste disposal and transmutation. In particular, the assessment of advanced fuel cycles requires an extensive knowledge of transuranics cross sections. Plutonium isotopes, but also americium, curium and up to californium isotope data are required with a small uncertainty in order to optimize significant features of the fuel cycle that have an impact on feasibility studies (e.g. neutron doses at fuel fabrication, decay heat in a repository, etc.). Different techniques are available to determine neutron cross sections experimentally, with the common denominator that a source of neutrons is necessary. It can either come from an accelerator that produces neutrons as a result of interactions between charged particles and a target, or it can come from a nuclear reactor. When the measurements are performed with an accelerator, they are referred to as differential since the analysis of the data provides the cross-sections for different discrete energies, i.e. σ(Ei), and for the diffusion cross sections for different discrete angles. Another approach is to irradiate a very pure sample in a test reactor such as the Advanced Test Reactor (ATR) at INL and, after a given time, determine the amount of the different transmutation products. The precise characterization of the nuclide densities before and after

  14. Assessing neutron generator output using neutron activation of silicon

    International Nuclear Information System (INIS)

    Kehayias, Pauli M.; Kehayias, Joseph J.

    2007-01-01

    D-T neutron generators are used for elemental composition analysis and medical applications. Often composition is determined by examining elemental ratios in which the knowledge of the neutron flux is unnecessary. However, the absolute value of the neutron flux is required when the generator is used for neutron activation analysis, to study radiation damage to materials, to monitor the operation of the generator, and to measure radiation exposure. We describe a method for absolute neutron output and flux measurements of low output D-T neutron generators using delayed activation of silicon. We irradiated a series of silicon oxide samples with 14.1 MeV neutrons and counted the resulting gamma rays of the 28 Al nucleus with an efficiency-calibrated detector. To minimize the photon self-absorption effects within the samples, we used a zero-thickness extrapolation technique by repeating the measurement with samples of different thicknesses. The neutron flux measured 26 cm away from the tritium target of a Thermo Electron A-325 D-T generator (Thermo Electron Corporation, Colorado Springs, CO) was 6.2 x 10 3 n/s/cm 2 ± 5%, which is consistent with the manufacturer's specifications

  15. Assessing neutron generator output using neutron activation of silicon

    Energy Technology Data Exchange (ETDEWEB)

    Kehayias, Pauli M. [Body Composition Laboratory, Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111 (United States); Kehayias, Joseph J. [Body Composition Laboratory, Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111 (United States)]. E-mail: joseph.kehayias@tufts.edu

    2007-08-15

    D-T neutron generators are used for elemental composition analysis and medical applications. Often composition is determined by examining elemental ratios in which the knowledge of the neutron flux is unnecessary. However, the absolute value of the neutron flux is required when the generator is used for neutron activation analysis, to study radiation damage to materials, to monitor the operation of the generator, and to measure radiation exposure. We describe a method for absolute neutron output and flux measurements of low output D-T neutron generators using delayed activation of silicon. We irradiated a series of silicon oxide samples with 14.1 MeV neutrons and counted the resulting gamma rays of the {sup 28}Al nucleus with an efficiency-calibrated detector. To minimize the photon self-absorption effects within the samples, we used a zero-thickness extrapolation technique by repeating the measurement with samples of different thicknesses. The neutron flux measured 26 cm away from the tritium target of a Thermo Electron A-325 D-T generator (Thermo Electron Corporation, Colorado Springs, CO) was 6.2 x 10{sup 3} n/s/cm{sup 2} {+-} 5%, which is consistent with the manufacturer's specifications.

  16. Fast neutron activation analysis in metallurgy

    International Nuclear Information System (INIS)

    Sterlinski, S.

    1981-01-01

    Article discusses the usage of a 14 MeV neutron generator for producing fast neutrons of different energies and intensities. A complete instrumental set-up for the neutron activation analysis (NAA) is given. In metallurgy the device is mainly used in the determination of oxygen and silicon in steel and non-ferrous metal, including different alloys

  17. Thick-foils activation technique for neutron spectrum unfolding with the MINUIT routine-Comparison with GEANT4 simulations

    Science.gov (United States)

    Vagena, E.; Theodorou, K.; Stoulos, S.

    2018-04-01

    Neutron activation technique has been applied using a proposed set of twelve thick metal foils (Au, As, Cd, In, Ir, Er, Mn, Ni, Se, Sm, W, Zn) for off-site measurements to obtain the neutron spectrum over a wide energy range (from thermal up to a few MeV) in intense neutron-gamma mixed fields such as around medical Linacs. The unfolding procedure takes into account the activation rates measured using thirteen (n , γ) and two (n , p) reactions without imposing a guess solution-spectrum. The MINUIT minimization routine unfolds a neutron spectrum that is dominated by fast neutrons (70%) peaking at 0.3 MeV, while the thermal peak corresponds to the 15% of the total neutron fluence equal to the epithermal-resonances area. The comparison of the unfolded neutron spectrum against the simulated one with the GEANT4 Monte-Carlo code shows a reasonable agreement within the measurement uncertainties. Therefore, the proposed set of activation thick-foils could be a useful tool in order to determine low flux neutrons spectrum in intense mixed field.

  18. Study on neutron activation analysis

    International Nuclear Information System (INIS)

    Chung, Yong Sam; Cho, Seung Yeon

    1993-01-01

    Environmental samples were analyzed quantitatively by neutron activation analysis using high resolution γ-ray spectrometry. The accuracy and precision of the method were checked by the analysis of reference materials, Urban Particulate Matter (NBS SRM 1648) and Coalfly ash (NBS SRM 1633a). Airborne particulates collected for 6 months with low volume air sampler at the outer area of Seoul were analyzed as the start of full scale airborne particulates research. We analyzed 19 trace elements from the samples and the NAA method was confirmed to be utilized for environmental pollution research. (Author)

  19. Neutronics activities for next generation devices

    International Nuclear Information System (INIS)

    Gohar, Y.

    1985-01-01

    Neutronic activities for the next generation devices are the subject of this paper. The main activities include TFCX and FPD blanket/shield studies, neutronic aspects of ETR/INTOR critical issues, and neutronics computational modules for the tokamak system code and tandem mirror reactor system code. Trade-off analyses, optimization studies, design problem investigations and computational models development for reactor parametric studies carried out for these activities are summarized

  20. Neutron fluence spectrometry using disk activation

    International Nuclear Information System (INIS)

    Loevestam, Goeran; Hult, Mikael; Fessler, Andreas; Gasparro, Joel; Kockerols, Pierre; Okkinga, Klaas; Tagziria, Hamid; Vanhavere, Filip; Wieslander, J.S. Elisabeth

    2009-01-01

    A simple and robust detector for spectrometry of environmental neutrons has been developed. The technique is based on neutron activation of a series of different metal disks followed by low-level gamma-ray spectrometry of the activated disks and subsequent neutron spectrum unfolding. The technique is similar to foil activation but here the applied neutron fluence rates are much lower than usually in the case of foil activation. The detector has been tested in quasi mono-energetic neutron fields with fluence rates in the order of 1000-10000 cm -2 s -1 , where the obtained spectra showed good agreement with spectra measured using a Bonner sphere spectrometer. The detector has also been tested using an AmBe source and at a neutron fluence rate of about 40 cm -2 s -1 , again, a good agreement with the assumed spectrum was achieved

  1. Neutron fluence spectrometry using disk activation

    Energy Technology Data Exchange (ETDEWEB)

    Loevestam, Goeran [EC-JRC-Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, B-2440 Geel (Belgium)], E-mail: goeran.loevestam@ec.europa.eu; Hult, Mikael; Fessler, Andreas; Gasparro, Joel; Kockerols, Pierre; Okkinga, Klaas [EC-JRC-Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, B-2440 Geel (Belgium); Tagziria, Hamid [EC-JRC-Institute for the Protection and the Security of the Citizen (IPSC), Via E. Fermi 1, I-21020 Ispra (Vatican City State, Holy See,) (Italy); Vanhavere, Filip [SCK-CEN, Boeretang, 2400 Mol (Belgium); Wieslander, J.S. Elisabeth [EC-JRC-Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, B-2440 Geel (Belgium); Department of Physics, P.O. Box 35 (YFL), FIN-40014, University of Jyvaeskylae (Finland)

    2009-01-15

    A simple and robust detector for spectrometry of environmental neutrons has been developed. The technique is based on neutron activation of a series of different metal disks followed by low-level gamma-ray spectrometry of the activated disks and subsequent neutron spectrum unfolding. The technique is similar to foil activation but here the applied neutron fluence rates are much lower than usually in the case of foil activation. The detector has been tested in quasi mono-energetic neutron fields with fluence rates in the order of 1000-10000 cm{sup -2} s{sup -1}, where the obtained spectra showed good agreement with spectra measured using a Bonner sphere spectrometer. The detector has also been tested using an AmBe source and at a neutron fluence rate of about 40 cm{sup -2} s{sup -1}, again, a good agreement with the assumed spectrum was achieved.

  2. Activation analysis of high pure quartz used as packing materials

    International Nuclear Information System (INIS)

    Luknitskij, V.A.; Morozov, B.A.

    1979-01-01

    A γ-spectrometric technique of neutron activation determination of microelements in quartz tubes used as a packing material for irradiation in reactors is reported. The analysis of 29 micro-admixtures in quartz tubes of USSR brands ''spectrtosil'' and ''KV'' was carried out. The γ-spectra of ''KV'' quartz irradiated by thermal and epithermal neutrons are presented. The activation by epithermal neutrons provides an activity gain for the nuclei whose resonance integral is high enough as compared to the activation cross-section with regard to thermal neutrons. The activation by epithermal neutrons permits additional determination of W, Cd, V, Th, Mn and Ni and provides for a substantial decrease in the activity of 24 Na, 42 K, 140 La, 46 Sc, 141 Ce, 51 Cr, and 59 Fe, which hinder the determination of the above-mentioned elements. The microelement composition of Soviet-made quartz varieties is compared to that of foreign-made quartz brands

  3. Manually controlled neutron-activation system

    International Nuclear Information System (INIS)

    Johns, R.A.; Carothers, G.A.

    1982-01-01

    A manually controlled neutron activation system, the Manual Reactor Activation System, was designed and built and has been operating at one of the Savannah River Plant's production reactors. With this system, samples can be irradiated for up to 24 hours and pneumatically transferred to a shielded repository for decay until their activity is low enough for them to be handled at a radiobench. The Manual Reactor Activation System was built to provide neutron activation of solid waste forms for the Alternative Waste Forms Leach Testing Program. Neutron activation of the bulk sample prior to leaching permits sensitive multielement radiometric analyses of the leachates

  4. Models for estimation of the 10B concentration after BPA-fructose complex infusion in patients during epithermal neutron irradiation in BNCT

    International Nuclear Information System (INIS)

    Ryynaenen, Paeivi M.; Kortesniemi, Mika; Coderre, Jeffrey A.; Diaz, Aidnag Z.; Hiismaeki, Pekka; Savolainen, Sauli E.

    2000-01-01

    Purpose: To create simple and reliable models for clinical practice for estimating the blood 10 B time-concentration curve after p-boronophenylalanine fructose complex (BPA-F) infusion in patients during neutron irradiation in boron neutron capture therapy (BNCT). Methods and Materials: BPA-F (290 mg BPA/kg body weight) was infused i.v. during two hours to 10 glioblastoma multiforme patients. Blood samples were collected during and after the infusion. Compartmental models and bi-exponential function fit were constructed based on the 10 B blood time-concentration curve. The constructed models were tested with data from six additional patients who received various amounts of infused BPA-F and data from one patient who received a one-hour infusion of 170 mg BPA/kg body weight. Results: The resulting open two-compartment model and bi-exponential function estimate the clearance of 10 B after 290 mg BPA/kg body weight infusion from the blood with satisfactory accuracy during the first irradiation field (1 ppm, i.e., 7%). The accuracy of the two models in predicting the clearance of 10 B during the second irradiation field are for two-compartment model 1.0 ppm (8%) and 0.2 ppm (2%) for bi-exponential function. The models predict the average blood 10 B concentration with an increasing accuracy as more data points are available during the treatment. Conclusion: By combining the two models, a robust and practical modeling tool is created for the estimation of the 10 B concentration in blood after BPA-F infusion

  5. neutron radiography

    International Nuclear Information System (INIS)

    Barton, J.P.

    1993-01-01

    Neutron radiography (or radiology) is a diverse filed that uses neutrons of various energies, subthermal, thermal, epithermal or fast in either steady state or pulsed mode to examine objects for industrial, medical, or other purposes, both microscopic and macroscopic. The applications include engineering design, biological studies, nondestructive inspection and materials evaluation. In the past decade, over 100 different centers in some 30 countries have published reports of pioneering activities using reactors, accelerators and isotopic neutron sources. While film transparency and electronic video are most common imaging methods for static or in motion objects respectively, there are other important data gathering techniques, including track etch, digital gauging and computed tomography. A survey of the world-wide progress shows the field to be gaining steadily in its diversity, its sophistication and its importance. (author)

  6. Fast neutron activation analysis by means of low voltage neutron generator

    Directory of Open Access Journals (Sweden)

    M.E. Medhat

    Full Text Available A description of D-T neutron generator (NG is presented. This machine can be used for fast neutron activation analysis applied to determine some selected elements, especially light elements, in different materials. Procedure of neutron flux determination and efficiency calculation is described. Examples of testing some Egyptian natural cosmetics are given. Keywords: Neutron generator, Fast neutron activation analysis, Elemental analysis

  7. Proceedings of national seminar neutron activation analysis

    International Nuclear Information System (INIS)

    Agus Taftazani; Muhayatun Santoso; Budi Haryanto; Khatarina Oginawati

    2010-11-01

    Proceedings of national seminar neutron activation analysis in 2010 with the theme of the Role of Nuclear Analytical Techniques in the Field of Environment, Health and Industry. The seminar was organized by Indonesians Neutron Activation Analysis and BATAN Forum. These proceedings contain the result of environmental research in BATAN, universities and institutions associated with the application on neutron activation analysis technique. The purpose of these proceedings was as a useful source of information to spur research and development of activation analysis applications in various fields for the Indonesian welfare. There are 40 articles. (PPIKSN).

  8. Neutron--neutron logging

    International Nuclear Information System (INIS)

    Allen, L.S.

    1977-01-01

    A borehole logging tool includes a steady-state source of fast neutrons, two epithermal neutron detectors, and two thermal neutron detectors. A count rate meter is connected to each neutron detector. A first ratio detector provides an indication of the porosity of the formation surrounding the borehole by determining the ratio of the outputs of the two count rate meters connected to the two epithermal neutron detectors. A second ratio detector provides an indication of both porosity and macroscopic absorption cross section of the formation surrounding the borehole by determining the ratio of the outputs of the two count rate meters connected to the two thermal neutron detectors. By comparing the signals of the two ratio detectors, oil bearing zones and salt water bearing zones within the formation being logged can be distinguished and the amount of oil saturation can be determined. 6 claims, 2 figures

  9. Neutron activation analysis for environmental trace element research determination of elemental composition of sediments in the Sea of Galillee, Israel

    Energy Technology Data Exchange (ETDEWEB)

    Lavi, N; Ne` eman, E; Brenner, S; Butenko, V [Tel Aviv Univ. (Israel). Medical School

    1996-12-01

    The aims of this work were to: a) demonstrate the effectiveness of instrumental neutron activation analysis for determining the background concentrations of trace elements in the sediments collected from the Sea of Gallile. b) determine the advantage factors for epithermal neutron irradiation. c) determine the contribution of silicon to the total {sup 28}Al activity by the {sup 28}Si(n,p){sup 28}Al reaction. c) check the validity of the method by determining the elemental content of U.S. NBS Standard Reference Material SRM-1633a (fly ash). d) calculate the average enrichment factors for the elements in sediments . e) determine the concentrations of the artificial radionuclides {sup 134}Cs, {sup 137}Cs and the naturally occurring radionuclides {sup 40}K, {sup 226}Ra and {sup 232}Th (authors).

  10. Monte Carlo method in neutron activation analysis

    International Nuclear Information System (INIS)

    Majerle, M.; Krasa, A.; Svoboda, O.; Wagner, V.; Adam, J.; Peetermans, S.; Slama, O.; Stegajlov, V.I.; Tsupko-Sitnikov, V.M.

    2009-01-01

    Neutron activation detectors are a useful technique for the neutron flux measurements in spallation experiments. The study of the usefulness and the accuracy of this method at similar experiments was performed with the help of Monte Carlo codes MCNPX and FLUKA

  11. Computer-automated neutron activation analysis system

    International Nuclear Information System (INIS)

    Minor, M.M.; Garcia, S.R.

    1983-01-01

    An automated delayed neutron counting and instrumental neutron activation analysis system has been developed at Los Alamos National Laboratory's Omega West Reactor (OWR) to analyze samples for uranium and 31 additional elements with a maximum throughput of 400 samples per day. 5 references

  12. Characterization of bauxite residue (red mud) for 235U, 238U, 232Th and 40K using neutron activation analysis and the radiation dose levels as modeled by MCNP.

    Science.gov (United States)

    Landsberger, S; Sharp, A; Wang, S; Pontikes, Y; Tkaczyk, A H

    2017-07-01

    This study employs thermal and epithermal neutron activation analysis (NAA) to quantitatively and specifically determine absorption dose rates to various body parts from uranium, thorium and potassium. Specifically, a case study of bauxite residue (red mud) from an industrial facility was used to demonstrate the feasibility of the NAA approach for radiological safety assessment, using small sample sizes to ascertain the activities of 235 U, 238 U, 232 Th and 40 K. This proof-of-concept was shown to produce reliable results and a similar approach could be used for quantitative assessment of other samples with possible radiological significance. 238 U and 232 Th were determined by epithermal and thermal neutron activation analysis, respectively. 235 U was determined based on the known isotopic ratio of 238 U/ 235 U. 40 K was also determined using epithermal neutron activation analysis to measure total potassium content and then subtracting its isotopic contribution. Furthermore, the work demonstrates the application of Monte Carlo Neutral-Particle (MCNP) simulations to estimate the radiation dose from large quantities of red mud, to assure the safety of humans and the surrounding environment. Phantoms were employed to observe the dose distribution throughout the human body demonstrating radiation effects on each individual organ. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Nondestructive neutron activation analysis of silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Vandergraaf, T. T.; Wikjord, A. G.

    1973-10-15

    Instrumentel neutron activation analysis was used to determine trace constituents in silicon carbide. Four commercial powders of different origin, an NBS reference material, and a single crystal were characterized. A total of 36 activation species were identified nondestructively by high resolution gamma spectrometry; quantitative results are given for 12 of the more predominant elements. The limitations of the method for certain elements are discussed. Consideration is given to the depression of the neutron flux by impurities with large neutron absorption cross sections. Radiation fields from the various specimens were estimated assuming all radionuclides have reached their saturation activities. (auth)

  14. Accurate measurements of neutron activation cross sections

    International Nuclear Information System (INIS)

    Semkova, V.

    1999-01-01

    The applications of some recent achievements of neutron activation method on high intensity neutron sources are considered from the view point of associated errors of cross sections data for neutron induced reaction. The important corrections in -y-spectrometry insuring precise determination of the induced radioactivity, methods for accurate determination of the energy and flux density of neutrons, produced by different sources, and investigations of deuterium beam composition are considered as factors determining the precision of the experimental data. The influence of the ion beam composition on the mean energy of neutrons has been investigated by measurement of the energy of neutrons induced by different magnetically analysed deuterium ion groups. Zr/Nb method for experimental determination of the neutron energy in the 13-15 MeV energy range allows to measure energy of neutrons from D-T reaction with uncertainty of 50 keV. Flux density spectra from D(d,n) E d = 9.53 MeV and Be(d,n) E d = 9.72 MeV are measured by PHRS and foil activation method. Future applications of the activation method on NG-12 are discussed. (author)

  15. The synchronous active neutron detection assay system

    International Nuclear Information System (INIS)

    Pickrell, M.M.; Kendall, P.K.

    1994-01-01

    We have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit a 14-MeV neutron generator developed by Schlumberger. The technique, termed synchronous active neutron detection (SAND), follows a method used routinely in other branches of physics to detect very small signals in presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed ''lock-in'' amplifiers. We have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. The Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. Results are preliminary but promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly; it also appears resilient to background neutron interference. The interrogating neutrons appear to be non-thermal and penetrating. Work remains to fully explore relevant physics and optimize instrument design

  16. Determination of silver, gold, zinc and copper in mineral samples by various techniques of instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Rodriguez R, N. I.; Rios M, C.; Pinedo V, J. L.; Yoho, M.; Landsberger, S.

    2015-09-01

    Using the method of instrumental neutron activation analysis, mineral exploration samples were analyzed in order to determine the concentrations of silver, gold, zinc and copper; these minerals being the main products of benefit of Tizapa and Cozamin mines. Samples were subjected to various techniques, where the type of radiation and counting methods were chosen based on the specific isotopic characteristics of each element. For calibration and determination of concentrations the comparator method was used, certified standards were subjected to the same conditions of irradiation and measurement that the prospecting samples. The irradiations were performed at the research reactor TRIGA Mark II of the University of Texas at Austin. The silver concentrations were determined by Cyclical Epithermal Neutron Activation Analysis. This method in combination with the transfer pneumatic system allowed a good analytical precision and accuracy in prospecting for silver, from photo peak measurement 657.7 keV of short half-life radionuclide 110 Ag. For the determination of gold and zinc, Epithermal Neutron Activation Analysis was used, the photo peaks analyzed corresponded to the energies 411.8 keV of radionuclide 199 Au and 438.6 keV of metastable radionuclide 69m Zn. On the other hand, copper quantification was based on the photo peak analysis of 1039.2 keV produced by the short half-life radionuclide 66 Cu, by Thermal Neutron Activation Analysis. The photo peaks measurement corresponding to gold, zinc and copper was performed using a Compton suppression system, which allowed an improvement in the signal to noise relationship, so that better detection limits and low uncertainties associated with the results were obtained. Comparing elemental concentrations the highest values in silver, zinc and copper was for samples of mine Tizapa. Regarding gold values were found in the same range for both mines. To evaluate the precision and accuracy of the methods used, various geological

  17. Investigation of Six Geological Samples From Wady Sitra Eastern Desert - Egypt Using K0 Neutron Activation Method

    International Nuclear Information System (INIS)

    Soliman, N.F.; Ashmawy, L.S.; Walley El-Dine, N.; Sroor, A.; Mohamed, T.El.

    2010-01-01

    k 0 - Neutron Activation Analysis (k 0 -NAA) is applied to investigate six geological samples collected from Wady Sitra at Eastern desert of Egypt during the survey of gold presence in this area. The samples together with a group of standard (Mo, Fe, Sb and W) are irradiated for 3 hours in one of the inner irradiation site of the Second Egyptian Training and Research Reactor (ETRR-2) operating at power of 19 MW. Mo, Fe and Sb are used to measure the neutron spectrum parameters α(epithermal non-ideality factor) and f (the thermal to epithermal flux ratio) while W is used to test the obtained results. The α( and f parameters are measured using the so-called bare triple monitor method and the obtained results was found to be f = 17.5 ± 0.35 and α(= 0.03±0.002. A Fortran computer program is designed and used to calculate the values of Q 0 (α)for the analyzed elements . The concentration values of 25 elements in the present rock samples have been presented

  18. Instrumental neutron activation analysis - a routine method

    International Nuclear Information System (INIS)

    Bruin, M. de.

    1983-01-01

    This thesis describes the way in which at IRI instrumental neutron activation analysis (INAA) has been developed into an automated system for routine analysis. The basis of this work are 20 publications describing the development of INAA since 1968. (Auth.)

  19. The Comparison Study of Neutron Activation Analysis and Fission Track Technique for Uranium Determination

    International Nuclear Information System (INIS)

    Sirinuntavid, Alice; Rodthongkom, Chouvana

    2007-08-01

    Full text: Comparison between Neutron Activation Analysis (NAA) and fission track technique for uranium determination in solid samples was studied by use of standard reference materials, i.e., ore, coal fly ash, soil. For NAA, the epithermal neutron was applied for activated irradiation. Then, the 74.5 keV gamma from U-239 or 277.7 keV gamma from Np-239 was measured. For high Uranium content samples, NAA method with 74.5 keV gamma measurement, gave higher precision result than the 277.7 keV gamma measurement method. NAA method with 277.7 keV gamma measurement, gave higher sensitivity and precision result for low Uranium content samples and the uranium contained less than 10 ppm samples. Nevertheless, the latter procedure needed longer time for neutron irradiation and analysis procedure. In comparison the results of Uranium analysis between NAA and fission track, it was found that no significant difference within 95 % of confidence level

  20. Neutron activation determination of iridium, gold, platinum, and silver in geologic samples

    International Nuclear Information System (INIS)

    Millard, H.T.

    1986-01-01

    Low-level methods for the determination of iridium and other noble metals have been important in recent years due to interest in locating abundance anomalies associated with the Cretaceous/Tertiary (K/T) boundary. Typical iridium anomalies are in the range of 1 to 100 ppb. Thus methods with detection limits near 0.1 ppb should be adequate to detect K/T boundary anomalies. Radiochemical neutron activation analysis methods continue to be required although instrumental neutron activation analysis techniques employing elaborate gamma-counters are under development. In the procedure employed in this study samples irradiated in the epithermal neutron facility of the U.S. Geological Survey TRIGA Reactor are treated with a mini-fire assay technique. The iridium, gold, and silver are collected in a 1-gram metallic lead button. Primary contaminants at this stage are arsenic and antimony. These can be removed by heating the button with a mixture of sodium peroxide and sodium hydroxide. The resulting 0.2-gram lead bead is counted in a Compton suppression spectrometer. Carrier yields are determined by reirradiation of the lead beads. This procedure has been applied to the U.S.G.S. Standard Rock PCC-1. and samples from K/T boundary sites in the Western Interior of North America. (author)

  1. Multielement analysis of rice flour-unpolished reference material by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Suzuki, Shogo; Hirai, Shoji

    1990-01-01

    Trace elements in NIES certified reference material No. 10-a∼10-c Rice Flour-Unpolished, prepared by the National Institute for Environmental Studies of Japan (NIES), were determined by instrumental neutron activation analysis (INAA). A set of three samples with different Cd concentration levels was subjected to analyses. Portions of each sample (ca. 200∼1000 mg) were irradiated, either with thermal neutrons without cadmium filter or with epithermal neutrons with cadmium filter, in the Musashi Institute of Technology Research Reactor (MITRR). The activated samples were analyzed by the three methods; conventional γ-ray spectrometry using a coaxial Ge detector, anticoincidence counting spectrometry, and coincidence counting spectrometry using a coaxial Ge detector and a well type NaI(Tl) detector. Concentrations of 26∼28 elements were determined by these methods. The values obtained for many elements, except for Mg and K, were in good agreement with those of the NIES certified and reference. Concentrations of 10 elements (S, Sc, V, Ag, Sb, Cs, Ba, La, Sm, Th), whose certified or reference values are not available from NIES, were also determined in this work. (author)

  2. Forensic neutron activation analysis - the Japanese scene

    International Nuclear Information System (INIS)

    Kishi, Tohru.

    1986-01-01

    The progress of forensic neutron activation analysis/FNAA/ in Japan is described. FNAA began in 1965 and during the past 20 years many cases have been handled; these include determination of toxic materials, comparison examination of physical evidences /e.g.,paints, metal fragments, plastics and inks/ and drug sample differenciation. Neutron activation analysis is applied routinely to the scientific criminal investigation as one of multielement analytical techniques. This paper also discusses these routine works. (author)

  3. Correction Factor Analysis Of Foil Activation And The Effect Of Neglecting The Correction On Neutron Flux And Spectrum Measurement; ANALISIS FAKTOR KOREKSI KEPING AKTIVASI DAN PENGARUH PENGABAIANNYA PADA PENGUKURAN FLUKS DAN SPEKTRUM NEUTRON

    Energy Technology Data Exchange (ETDEWEB)

    Radiyanti, Ita Budi; Hamzah, Amir; Pinem, Surian [Multipurpose Reactor Centre Indonesia, Serpong, (Indonesia)

    1996-04-15

    Foil activation method is commonly used in flux and neutron spectrum measurement in nuclear reactor and other research. The effect of the thickness, type of foil material and neutron spectrum shape on the self shielding correction and activities correction on the edges of the foil have been analyzed. Also the effect of neglecting those correction factors on neutron flux and spectrum measurement were analyzed. The calculation of the correction factor has been done by using the program which had been verified for several foils. The foils used are Au, In. Cu, Co and Dy of 0.00254 cm -0.127 cm thickness and 1.27 cm diameter. The result showed that the correction factor foils were not similar due to the variation of activation cross section and neutron spectrum shape. For the neutron spectrum in RS-2 multi purpose reactor GAS using foils of 0.00254 cm thick. The effect of neglecting correction factor on thermal flux measurement for Au, In, Co and Cu were less than -6%, for Dy was about -25%. On epithermal flux measurement for Au and In were about -60%, Co and Dy was -12% and -6%, for Cu less than -2%. The effect of neglecting correction factor on spectrum measurement was the change on the neutron flux density values along neutron energy region.

  4. Design and testing of a rotating, cooled device for extra-corporate treatment of liver cancer by BNCT in the epithermal neutron beam at the HFR Petten

    International Nuclear Information System (INIS)

    Moss, Ray; Nievaart, Sander; Pott, Lucien; Wittig, Andrea; Sauerwein, Wolfgang

    2006-01-01

    As part of the joint project on extra-corporal treatment of liver cancer by BNCT between JRC Petten and the University Hospital Essen, a facility has been designed and built to contain the liver during its irradiation treatment at the HFR Petten. The design consists of a rotating spheroid shaped PMMA holder, manufactured to open at the equator and closed by screwing together, surrounded by PMMA and graphite blocks. A validation exercise has been performed regarding both the nuclear conditions and the physical conditions. For the former, activation foil sets of Au, Cu and Mn, were irradiated at positions inside the liver holder filled with water, whilst a second measurement campaign has been performed using gel dosimetry. For the physical test, it is required to operate (rotate) the facility for up to 4 hours and to maintain the liver at approximately 4degC. The latter test was performed using 'cold gun sprays' that inject cold air near the liver holder. Both the nuclear and physical validation tests were performed successfully. (author)

  5. Application of the neutron activation analysis technique in trace elements analysis

    International Nuclear Information System (INIS)

    Khamis, I.; Sarheel, A.; Al-Somel, N.

    2006-12-01

    The main objective in this study is the implementation k 0 -standardization method (single comparator method) using gold comparator as a routine method in neutron activation analysis laboratory in Engineering Nuclear Department. Cadmium ratio Rcd; Cd-ratio = [A s p/(A s p) C d] and the nuclear reactor constants (f=φ t h/φ e pi subcadimum thermal- to- epithermal neutron flux ratio and α with describing the φ e (E)∼ 1/E 1+α neutron flux distribution) were determined in the inner and outer irradiation sites at MNS Reactor. K 0 -IAEA software, which provided by the Agency, has been installed and applied in our laboratory. Trace elements in many kinds of samples (biological, environmental, alloy ...etc) were determined using K 0 -IAEA software. The results of standard reference materials (SRM's) obtained in this work show a good agreement with the certified values, and we got these results with a good accuracy closer to results which we got from relative NAA method. (author)

  6. Calibration of SPND/Rhodium device for mapping the neutron fluence in the IEA-R1 reactor by means of the activation foil method; Calibracao de um dispositivo de mapeamento de fluxo de neutrons - SNPD/Rodio no reator IEA-R1, por meio do metodo de ativacao de folhas

    Energy Technology Data Exchange (ETDEWEB)

    Ricci Filho, Walter; Dias, Mauro S.; Tondin, Julio B.M.; Koskinas, Marina F. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2002-07-01

    The IEA-R1 reactor has undergone a modernization to increase its operating power to 5 MW, in order to allow a more efficient production of radioisotopes. The objective of this work is to provide the reactor with flux monitoring device using a rhodium Self-Powered Neutron Detector (SPND). The work presents the results obtained with Rhodium-SPND in several irradiation positions inside the reactor core. A calibration procedure has been performed by means of {sup 197} Au activation foils, with and without cadmium cover, in order do measure the thermal and epithermal neutron fluxes. (author)

  7. Designing an Epithermal Neutron Beam for Boron Neutron Capture Therapy for the Fusion Reactions 2H(d,n)3He and 3H(d,n)4He1

    International Nuclear Information System (INIS)

    Verbeke, J.M.; Costes, S.V.; Bleuel, D.; Vujic, J.; Leung, K.N.

    1998-01-01

    A beam shaping assembly has been designed to moderate high energy neutrons from the fusion reactions 2 H(d,N) 3 He and 3 H(d,n) 4 He for use fin boron neutron capture therapy. The low neutron yield of the 2 H(d,n) 3 He reaction led to unacceptably long treatment times. However, a 160 mA deuteron beam of energy 400 keV led to a treatment time of 120 minutes with the reaction 3 H(d,n) 4 He. Equivalent doses of 9.6 Gy-Eq and 21.9 Gy-Eq to the skin and to a 8 cm deep tumor respectively have been computed

  8. Determination of phosphorus using derivative neutron activation

    International Nuclear Information System (INIS)

    Scindia, Y.M.; Nair, A.G.C.; Reddy, A.V.R.; Manohar, S.B.

    2002-01-01

    For the determination of phosphorus in different matrices, the derivative neutron activation analysis is especially applicable to aqueous samples, since the conventional neutron activation analysis is not useful for the determination of phosphorus. Phosphorus when reacted with ammonium molybdate 4 hydrate and ammonium metavanadate forms molybdo vanado phosphoric acid. This complex is preconcentrated by extracting into methyl isobutyl ketone. The organic phase containing the molybdo vanado phosphoric acid is neutron activated and the phosphorus is determined through the activation product of 52 V. Preparation of this complex, its stoichiometry, application to trace level determination of phosphorus and improved detection limit are discussed. This method was applied for the analysis of industrial effluent samples. (author)

  9. A neutron irradiator to perform nuclear activation

    International Nuclear Information System (INIS)

    Zamboni, C. B.; Zahn, G.S.; Figueredo, A. M. G.; Madi, T. F.; Yoriyaz, H.; Lima, R. B.; Shtejer, K.; Dalaqua Jr, L.

    2001-01-01

    The development of appropriate nuclear instrumentation to perform neutron activation analyze (NAA), using thermal and fast neutrons, can be useful to investigate materials outside the reactor premises. Considering this fact, a small size neutron irradiator prototype was developed at IPEN facilities (Instituto de Pesquisas Energeticas e Nucleares - Brazil). Basically, this prototype consists of a cylinder of 1200 mm long and 985 mm diameter (filled with paraffin) with two Am-Be sources (600GBq each) arranged in the longitudinal direction of its geometric center. The material to be irradiated is positioned at a radial direction of the cylinder between the two Am-Be sources. The main advantage of this irradiator is a very stable neutron flux eliminating the use of standard material (measure of the induced activity in the sample by comparative method). This way the process became agile, practical and economic, but quantities at mg levels of samples are necessary to achieve good sensitivity, when the material has a low microscopy neutron cross section. As fast and thermal neutron can be used, the flux distribution, for both, were calculated and the prototype performance is discussed

  10. A review of conventional explosives detection using active neutron interrogation

    International Nuclear Information System (INIS)

    Whetstone, Z.D.; Kearfott, K.J.

    2014-01-01

    Conventional explosives are relatively easy to obtain and may cause massive harm to people and property. There are several tools employed by law enforcement to detect explosives, but these can be subverted. Active neutron interrogation is a viable alternative to those techniques, and includes: fast neutron analysis, thermal neutron analysis, pulsed fast/thermal neutron analysis, neutron elastic scatter, and fast neutron radiography. These methods vary based on neutron energy and radiation detected. A thorough review of the principles behind, advantages, and disadvantages of the different types of active neutron interrogation is presented. (author)

  11. Characterization of the Ljubljana TRIGA thermal column neutron radiographic facility

    International Nuclear Information System (INIS)

    Nemec, T.; Rant, J.; Kristof, E.; Glumac, B.

    1995-01-01

    An extensive characterization of the neutron beam of the existing neutron radiographic facility in the thermal column of the Ljubljana Triga Mark II research reactor is in progress. Neutron beam characteristics are needed to determine the effect of various neutron and gamma radiation on the neutron radiographic image. Commercially available medical scintillator converter screens based on Gd dioxy sulphite as well as Gd metal neutron converters are used to record neutron radiographic image. Thermal, epithermal and fast neutron fluxes were measured using Au and In activation detectors and cadmium ratio is determined. Neutron beam flux profiles are measured by film densitometry and by Au activation detector wires. By exposing films shielded by boral or lead plates individual contributions of thermal, epithermal neutrons and gamma radiation are estimated by densitometric measurements. By recording images of neutron image quality indicators BPI (Beam Purity Indicator) and SI (Sensitivity Indicator) produced by Riso, standard neutron radiography image characteristic are established. In gamma dosimetric measurements thermoluminescent detectors (CaF 2 Mn) are used. (author)

  12. Determination of Neutron Flux Parameter f and α and k0 Factor in Irradiation Facility of RSG GA Siwabessy reactor

    International Nuclear Information System (INIS)

    Amir Hamzah

    2004-01-01

    Determination of neutron flux thermal to epithermal ratio f and parameter α and k 0 factor has been done in irradiation facility of RSG G.A. Siwabessy reactor. Those parameters are needed to determine the concentration of an element in a sample using k 0 NAA method. Parameters f was measured using foil activation method and α parameter was obtained from power function fitting at epithermal neutron spectrum. Based on the fitting method the a parameter was determined of 0.0267,0.0255 and -0.0346 at system rabbit, IP2 and CIP irradiation position. The k 0 factor is depended on absolute gamma fraction. The neutron flux thermal to epithermal ratio f at all rabbit system is closed to 40. (author)

  13. Applications of neutron activation analysis in industry

    International Nuclear Information System (INIS)

    Zaini Hamzah.

    1985-01-01

    Neutron activation analysis technique is discussed in brief. This technique is used for quality control of raw materials, process materials and finished products, as well as activities in research and development for the improvement of the products and new products. The uses of this technique in several experienced industries are mentioned (author)

  14. Study of spectral response of a neutron filter. Design of a method to adjust spectra

    International Nuclear Information System (INIS)

    Colomb-Dolci, F.

    1999-02-01

    The first part of this thesis describes an experimental method which intends to determine a neutron spectrum in the epithermal range [1 eV -10 keV]. Based on measurements of reaction rates provided by activation foils, it gives flux level in each energy range corresponding to each probe. This method can be used in any reactor location or in a neutron beam. It can determine scepter on eight energy groups, five groups in the epithermal range. The second part of this thesis presents a study of an epithermal neutron beam design, in the frame of Neutron Capture Therapy. A beam tube was specially built to test filters made up of different materials. Its geometry was designed to favour epithermal neutron crossing and to cut thermal and fast neutrons. A code scheme was validated to simulate the device response with a Monte Carlo code. Measurements were made at ISIS reactor and experimental spectra were compared to calculated ones. This validated code scheme was used to simulate different materials usable as shields in the tube. A study of these shields is presented at the end of this thesis. (author)

  15. Neutron Activation analysis of waste water

    International Nuclear Information System (INIS)

    Hernandez H, V.

    1997-01-01

    An instrumental neutron activation analysis for the simultaneous determination of chlorine, bromine, sodium, manganese, cobalt, copper, chromium, zinc, nickel, antimony and iron in waste water is described. They were determined in waste water samples under normal conditions by non-destructive neutron activation simultaneously using a suitable monostandard method. Standardized water samples were used and irradiated in polyethylene ampoules at a neutron flux of 10 13 cm -2 s -1 for periods of 1 minute, 1 and 10 hours. A Ge hyperpure detector was used for your activity determination, with count times of 60, 180, 300 and 600 seconds. The obtained results show than the method can be utilized for the determination of this elements without realize anything previous treatment of the samples. (Author)

  16. Miniature neutron-alpha activation spectrometer

    International Nuclear Information System (INIS)

    Rhodes, Edgar; Goldsten, John; Holloway, James Paul; He, Zhong

    2002-01-01

    We are developing a miniature neutron-alpha activation spectrometer for in-situ analysis of chem-bio samples, including rocks, fines, ices, and drill cores, suitable for a lander or Rover platform for Mars or outer-planet missions. In the neutron-activation mode, penetrating analysis will be performed of the whole sample using a γ spectrometer and in the α-activation mode, the sample surface will be analyzed using Rutherford-backscatter and x-ray spectrometers. Novel in our approach is the development of a switchable radioactive neutron source and a small high-resolution γ detector. The detectors and electronics will benefit from remote unattended operation capabilities resulting from our NEAR XGRS heritage and recent development of a Ge γ detector for MESSENGER. Much of the technology used in this instrument can be adapted to portable or unattended terrestrial applications for detection of explosives, chemical toxins, nuclear weapons, and contraband

  17. Determination of Al, Si and P in certified reference materials by Instrumental Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Noyori, Amanda; Saiki, Mitiko, E-mail: anoyori@gmail.com, E-mail: mitiko@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    Neutron analysis activation is not commonly used for aluminum, phosphorus and silicon determination, due to the difficulty to obtain reliable results. In this study, Al was determined by measuring {sup 28}Al and the contribution of P and Si due to {sup 28}Al formed in {sup 31}P(n,α){sup 28}Al and {sup 28}Si(n,p){sup 28}Al reactions were corrected using correction factors determined experimentally. Phosphorus was determined by measuring {sup 32}P (pure beta emitter) formed in reaction {sup 31}P(n,γ){sup 32}P. Silicon was determined by epithermal neutron analysis activation (ENAA) and measuring {sup 29}Al radionuclide formed in {sup 29}Si(n,p){sup 29}Al reaction. Aliquots of certified reference materials (CRMs) and synthetic standards of the elements were irradiated together, using the pneumatic transfer station of IEA-R1 nuclear research reactor. Results obtained for biological and geological CRMs showed good precision and accuracy with |Z-score| < 2 for Al, P and Si determinations. The detection limits for Al, P and Si determinations CRMs were also evaluated. Results obtained in this study demonstrated the viability of applying INAA procedures in the determination of Al, P and Si. (author)

  18. Determination of Al, Si and P in certified reference materials by Instrumental Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Noyori, Amanda; Saiki, Mitiko

    2017-01-01

    Neutron analysis activation is not commonly used for aluminum, phosphorus and silicon determination, due to the difficulty to obtain reliable results. In this study, Al was determined by measuring "2"8Al and the contribution of P and Si due to "2"8Al formed in "3"1P(n,α)"2"8Al and "2"8Si(n,p)"2"8Al reactions were corrected using correction factors determined experimentally. Phosphorus was determined by measuring "3"2P (pure beta emitter) formed in reaction "3"1P(n,γ)"3"2P. Silicon was determined by epithermal neutron analysis activation (ENAA) and measuring "2"9Al radionuclide formed in "2"9Si(n,p)"2"9Al reaction. Aliquots of certified reference materials (CRMs) and synthetic standards of the elements were irradiated together, using the pneumatic transfer station of IEA-R1 nuclear research reactor. Results obtained for biological and geological CRMs showed good precision and accuracy with |Z-score| < 2 for Al, P and Si determinations. The detection limits for Al, P and Si determinations CRMs were also evaluated. Results obtained in this study demonstrated the viability of applying INAA procedures in the determination of Al, P and Si. (author)

  19. Neutron activation analysis in minerals prospecting

    International Nuclear Information System (INIS)

    Gomez, H.; Duque O, J.

    1988-01-01

    One method multielemental analysis in geological samples has been developed by neutron activation analysis without using standards and by eliminating many of the error sources of the absolute method. It uses the ratio of the activities induced by mass unit, between the element in the sample and one cobalt monitor. The detection limits are good for more than thirty elements in many prospecting programs, with a standard deviation less than 7%. The neutron flux used is 2x10 11 nxcm -2 .S -1 and the HPGE detector has a relative efficiency of 20% and an energy resolution of 1.9 KeV in 1332 KeV photopeak

  20. An Assessment of Elemental Compositions and Concentrations in a Marble Sample from Hatnub Area using Internal Mono Standard Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Soliman, N.F.; EL-Shershaby, A.; EL-Bahi, S.; Walley El-Dine, N.; Abd El-Halim, E.S.; Afifi, S.

    2012-01-01

    A marble sample was taken from Hatnub area near Asyot, where a high pollution is expected. The sample was specially treated and prepared for elemental analysis using the k 0 -based internal mono standard neutron activation analysis . The irradiation facility of the first Egyptian Training Research Reactor (ETRR-1) was used to irradiate the sample together with gold and zirconium monitor samples. The pneumatic irradiation rabbit system (PIRS) built in the vertical thermal column of the second Egyptian Training Research Reactor (ETRR-2) was used to irradiate another weight of the marble sample and a sample from a certificated reference material JB-1 for short time irradiation. A new method was developed to measure the thermal to epithermal neutron flux ratio and the deviation in the real epithermal neutron spectrum ( 1/E 1±a lpha ) from the ideal (1/E ). The elemental analysis was carried out by high-resolution gamma-ray spectrometry. The accuracy of the internal mono standard method has been evaluated by analyzing the JB-1 certified reference material

  1. Neutron activation analysis: principle and methods

    International Nuclear Information System (INIS)

    Reddy, A.V.R.; Acharya, R.

    2006-01-01

    Neutron activation analysis (NAA) is a powerful isotope specific nuclear analytical technique for simultaneous determination of elemental composition of major, minor and trace elements in diverse matrices. The technique is capable of yielding high analytical sensitivity and low detection limits (ppm to ppb). Due to high penetration power of neutrons and gamma rays, NAA experiences negligible matrix effects in the samples of different origins. Depending on the sample matrix and element of interest NAA technique is used non-destructively, known as instrumental neutron activation analysis (INAA), or through chemical NAA methods. The present article describes principle of NAA, different methods and gives a overview some applications in the fields like environment, biology, geology, material sciences, nuclear technology and forensic sciences. (author)

  2. Limitations for qualitative and quantitative neutron activation analysis using reactor neutrons

    International Nuclear Information System (INIS)

    El-Abbady, W.H.; El-Tanahy, Z.H.; El-Hagg, A.A.; Hassan, A.M.

    1999-01-01

    In this work, the most important limitations for qualitative and quantitative analysis using reactor neutrons for activation are reviewed. Each limitation is discussed using different examples of activated samples. Photopeak estimation, nuclear reactions interference and neutron flux measurements are taken into consideration. Solutions for high accuracy evaluation in neutron activation analysis applications are given. (author)

  3. Notes on neutron flux measurement

    International Nuclear Information System (INIS)

    Alcala Ruiz, F.

    1984-01-01

    The main purpose of this work is to get an useful guide to carry out topical neutron flux measurements. Although the foil activation technique is used in the majority of the cases, other techniques, such as those based on fission chambers and self-powered neutron detectors, are also shown. Special interest is given to the description and application of corrections on the measurement of relative and absolute induced activities by several types of detectors (scintillators, G-M and gas proportional counters). The thermal arid epithermal neutron fluxes, as determined in this work, are conventional or effective (West cots fluxes), which are extensively used by the reactor experimentalists; however, we also give some expressions where they are related to the integrated neutron fluxes, which are used in neutron calculations. (Author) 16 refs

  4. Procedure and code for calculating black control rods taking into account epithermal absorption, code CAS-1

    International Nuclear Information System (INIS)

    Martinc, R.; Trivunac, N.; Zivkovic, Z.

    1964-12-01

    This report describes the computer code CAS-1, calculation method and procedure applied for calculating the black control rods taking into account the epithermal neutron absorption. Results obtained for supercell method applied for regular lattice reflected in the multiplication medium is part of this report in addition to the computer code manual

  5. Analysis of coal by neutron activation

    International Nuclear Information System (INIS)

    Burtner, D.R.

    1983-01-01

    The development of a thermal-neutron activation analysis procedure for determining elemental concentrations in whole coal samples, and the goal of combining this technique with other nuclear methods for determining a total mass balance in these and similar complex materials, is described. Problems of applying a fast-neutron activation analysis method for nitrogen are discussed, as well as an efficient procedure for drying and packaging coal samples. A thermal-neutron activation analysis (TNAA) procedure was developed for determining up to 27 elements in coal samples from the US, China, Nigeria, and Brazil. The comparator form of TNAA was applied, using a unique multielement standard, which contained 48 elements. The difference in net photopeak counts between sample and standard, due to γ-ray attenuation, was reduced by preparing this standard in an organic matrix, which simulates the composition and physical structure of the coal material. The simultaneous irradiation of several aliquots of this standard enabled high precision and accuracy to be attained. An accurate value for oxygen, determined by fast-neutron activation analysis, is used to correct for this effect in the nitrogen determination method

  6. General principles of neutron activation analysis

    International Nuclear Information System (INIS)

    Dostal, J.; Elson, C.

    1980-01-01

    Aspects of the principles of atomic and nuclear structure and the processes of radioactivity, nuclear transformation, and the interaction of radiations with matter which are of direct relevance to neutron activation analysis and its application to geologic materials are discussed. (L.L.)

  7. Neutron Activation Analysis with k0 Standardization

    International Nuclear Information System (INIS)

    Pomme, S.

    1998-01-01

    SCK-CEN's programme on Neutron Activation Analysis with k 0 -standardisation aims to: (1) develop and implement k 0 -standardisation method for NAA; (2) to exploit the inherent qualities of NAA such as accuracy, traceability, and multi-element capability; (3) to acquire technical spin-off for nuclear measurements services. Main achievements in 1997 are reported

  8. Combined neutron activation analysis techniques for multiple purposes at Portuguese research reactor

    International Nuclear Information System (INIS)

    Dung, H.M.; Freitas, M.C.; Beasley, D.; Almeida, S.M.; Dionisio, I; Canha, N.H.; Galinha, C.; Marques, J.G.

    2010-01-01

    Full text: Developments of the neutron activation analysis (NAA) techniques using Compton suppression system (CSS), fast pneumatic irradiation facility (SIPRA), epithermal neutron and automatic sample changers (ASCs) associated with the traditional NAA for trace element determination in various sample types are described with reference to specific conditions at the 1 MW Portuguese research reactor (RPI). Experiences in application of k o -IAEA software for data processing in order to deduce the results are also discussed. A selected number of sample types which are intended to the application in biological and environmental areas as well as industrial and material samples are demonstrated which provide challenges in the irradiation, measurement and the interpretation of data to which in most cases a combined solution should be made. The role that each NAA technique can play in the combined scheme along with their optimized characteristics has been studied and shown. The combined NAA techniques at RPI established for on-going and potential projects as well as analysis service with respect to the element scope (48), typically Ag, Al, As, Au, Ba, Br, Ca, Cd, Ce, CI, Co, Cr, Cs, Cu, Dy, Er, Eu, F, Fe, Ga, Hf, Hg, I, In, K, La, Mg, Mn, Mo, Na, Rb, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Th, Ti, U, V, W, Vb, Zn and Zr along with detection limits, accuracies and precision's have been evaluated as a trace analysis method meeting the requirements of the intended applications

  9. Passive neutron dosemeter with activation detector

    Energy Technology Data Exchange (ETDEWEB)

    Valero L, C.; Banuelos F, A.; Guzman G, K. A.; Borja H, C. G.; Hernandez D, V. M.; Vega C, H. R., E-mail: fermineutron@yahoo.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2011-10-15

    A passive neutron dosemeter with {sup 197}Au activation detector has been developed. The area dosemeter was made as a 20.5 {phi} x 20.5 cm{sup 2} polyethylene moderator, with a polyethylene pug where a {sup 197}Au foil can be located either parallel or perpendicular to moderator axis. Using Monte Carlo methods, with the MCNP5 code. With the fluence response and the fluence-to-equivalent dose conversion coefficients from ICRP-74, responses to H*(10) were also calculated, these were compared against responses of commercially available neutron area monitors and dosemeters. (Author)

  10. Conversion ratio in epithermal PWR, in thorium and uranium cycle

    International Nuclear Information System (INIS)

    Barroso, D.E.G.

    1982-01-01

    Results obtained for the conversion ratio in PWR reactors with close lattices, operating in thorium and uranium cycles, are presented. The study of those reactors is done in an unitary fuel cell of the lattices with several ratios V sub(M)/V sub(F), considering only the equilibrium cycles and adopting a non-spatial depletion calculation model, aiming to simulate mass flux of reactor heavy elements in the reactor. The neutronic analysis and the cross sections generation are done with Hammer computer code, with one critical apreciation about the application of this code in epithermal systems and with modifications introduced in the library of basic data. (E.G.) [pt

  11. Analysis by neutronic activation of the active principles of MIBI

    International Nuclear Information System (INIS)

    Capote Rodriguez, G.; Hernandez Rivero, A.T.; Moreno Bermudez, J.; Ribeiro Guevara, S.; Molina Insfran, J.; Perez Zayas, G.

    1997-01-01

    In the present job the obtained results are shown through the application of an analysis by neutronic activation, in their instrumental variant, for the determination of the elementary composition of three Cuban radiopharmaceuticals. (author) [es

  12. Detection of explosives and illicit drugs using neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Kiraly, B. E-mail: kiralyb@tigris.klte.hu; Sanami, T.; Doczi, R.; Csikai, J

    2004-01-01

    A procedure developed for the determination of the flux perturbation factor required for the thermal neutron activation analysis of bulky samples of unknown composition has been extended for epithermal neutrons using hydrogenous and graphite moderators. Measurements on the diffusion and backscattering of thermal neutrons in soil components were carried out for the development of novel nuclear methods in order to speed up the humanitarian demining process. Results obtained for the diffusion length were checked by MCNP-4C calculations. In addition, the effect of the weight and density of the explosives on the observation of the anomaly in the reflected thermal neutrons was examined by using different dummy landmines.

  13. High-capacity neutron activation analysis facility

    International Nuclear Information System (INIS)

    Hochel, R.C.

    1979-01-01

    A high-capacity neutron activation analysis facility, the Reactor Activation Facility, was designed and built and has been in operation for about a year at one of the Savannah River Plant's production reactors. The facility determines uranium and about 19 other trace elements in hydrogeochemical samples collected in the National Uranium Resource Evaluation program. The facility has a demonstrated average analysis rate of over 10,000 samples per month, and a peak rate of over 16,000 samples per month. Uranium is determined by cyclic activation and delayed neutron counting of the U-235 fission products; other elements are determined from gamma-ray spectra recorded in subsequent irradiation, decay, and counting steps. The method relies on the absolute activation technique and is highly automated for round-the-clock unattended operation

  14. High-capacity neutron activation analysis facility

    International Nuclear Information System (INIS)

    Hochel, R.C.; Bowman, W.W.; Zeh, C.W.

    1980-01-01

    A high-capacity neutron activation analysis facility, the Reactor Activation Facility, was designed and built and has been in operation for about a year at one of the Savannah River Plant's production reactors. The facility determines uranium and about 19 other elements in hydrogeochemical samples collected in the National Uranium Resource Evaluation program, which is sponsored and funded by the United States Department of Energy, Grand Junction Office. The facility has a demonstrated average analysis rate of over 10,000 samples per month, and a peak rate of over 16,000 samples per month. Uranium is determined by cyclic activation and delayed neutron counting of the U-235 fission products; other elements are determined from gamma-ray spectra recorded in subsequent irradiation, decay, and counting steps. The method relies on the absolute activation technique and is highly automated for round-the-clock unattended operation

  15. Neutron activation analysis of final molasses from cuban sugar industry

    International Nuclear Information System (INIS)

    Griffith, J.; Gonzalez, E.; Rosenberg, R.J.; Diaz-Rizo, O.

    1996-01-01

    Thermal and epithermal non-destructive activation analyses have been performed on samples of final molasses from 14 different sugar factories , covering the most important regions in Cuba. From the first measurement after irradiation at the Triga Mark reactor (VTT), the concentration of more than 15 elements is reported. The almost constant elemental composition shows that they can be used equally for different purposes as animal foodstuff and for the manufacture of biotechnological products. This work is part of a research project developed in order to establish a complete characterization of Cuban sugar molasses. (author). 7 refs., 2 tabs

  16. Neutron activation analysis-comparative (NAAC)

    International Nuclear Information System (INIS)

    Zimmer, W.H.

    1979-01-01

    A software system for the reduction of comparative neutron activation analysis data is presented. Libraries are constructed to contain the elemental composition and isotopic nuclear data of an unlimited number of standards. Ratios to unknown sample data are performed by standard calibrations. Interfering peak corrections, second-order activation-product corrections, and deconvolution of multiplets are applied automatically. Passive gamma-energy analysis can be performed with the same software. 3 figures

  17. A neutron beam polarizer for study of parity violation in neutron-nucleus interactions

    International Nuclear Information System (INIS)

    Penttilae, S.I.; Bowman, J.D.; Delheij, P.P.; Frankle, C.M.; Haase, D.G.; Postma, H.; Seestrom, S.J.; Yen, Y.

    1995-01-01

    A dynamically-polarized proton target operating at 5 Tesla and 1 K has been built to polarize an epithermal neutron beam for studies of parity violation in compound-nuclear resonances. Nearly 0.9 proton polarization was obtained in an electron-beam irradiated ammonia target. This was used to produce a neutron beam polarization of 0.7 at epithermal energies. The combination of the polarized proton target and the LANSCE spallation neutron source produces the most intense pulsed polarized epithermal neutron beam in the world. The neutron-beam polarizer is described and methods to determine neutron beam polarization are presented. copyright 1995 American Institute of Physics

  18. Nanogram determination of arsenic in biological reference materials by non-destructive Compton suppression neutron activation analysis

    International Nuclear Information System (INIS)

    Petra, M.; Landsberger, S.; Swift, G.

    1990-01-01

    Non-destructive epithermal neutron activation analysis in conjunction with Compton suppression has been applied to determine arsenic in seven biological standard reference materials from the National Institute of Standards and Technology. The accuracy is in excellent agreement with all the certified values and compilation results. For four of the materials detection limits between 1-4 ng/g were easily achieved while for three others they ranged from 18-50 ng/g. Overall analytical precision typically varied between 2-4% for five of the reference materials while for two other it was between 12-16%. These methods clearly demonstrate that through a judicious approach of anti-coincidence techniques, nanogram quantities of arsenic can be reliably determined without the need for labor intensive chemical separations. (orig.)

  19. Development of Cold Neutron Activation Station at HANARO Cold Neutron Source

    International Nuclear Information System (INIS)

    Sun, G. M.; Hoang, S. M. T.; Moon, J. H.; Chung, Y. S.; Cho, S. J.; Lee, K. H.; Park, B. G.; Choi, H. D.

    2012-01-01

    A new cold neutron source at the HANARO Research Reactor had been constructed in the framework of a five-year project, and ended in 2009. It has seven neutron guides, among which five guides were already allocated for a number of neutron scattering instruments. A new two-year project to develop a Cold Neutron Activation Station (CONAS) was carried out at the two neutron guides since May 2010, which was supported by the program of the Ministry of Education, Science and Technology, Korea. Fig. 1 shows the location of CONAS. CONAS is a complex facility including several radioanalytical instruments utilizing neutron capture reaction to analyze elements in a sample. It was designed to include three instruments like a CN-PGAA (Cold Neutron - Prompt Gamma Activation Analysis), a CN-NIPS (Cold Neutron - Neutron Induced Pair Spectrometer), and a CN-NDP (Cold Neutron - Neutron-induced prompt charged particle Depth Profiling). Fig. 2 shows the conceptual configuration of the CONAS concrete bioshield and the instruments. CN-PGAA and CN-NIPS measure the gamma-rays promptly emitted from the sample after neutron capture, whereas CN-NDP is a probe to measure the charged particles emitted from the sample surface after neutron capture. For this, we constructed two cold neutron guides called CG1 and CG2B guides from the CNS

  20. Measurements of neutron flux in the RA reactor; Merenje karakteristika neutronskog fluksa u reaktoru RA

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    This report includes results of the following measurements performed at the RA reactor: thermal neutron flux in the experimental channels, epithermal and fast neutron flux, neutron flux in the biological shield, neutron flux distribution in the reactor cell.

  1. Secondary neutron production from thick Pb target by light particle irradiation

    CERN Document Server

    Adloff, J C; Debeauvais, M; Fernández, F; Krivopustov, M; Kulakov, B A; Sosnin, A; Zamani, M

    1999-01-01

    Neutron multiplicities from spallation neutron sources were measured by Solid State Nuclear Track Detectors. Light particles as protons, deuterons and alphas in the GeV range were used on Pb targets. For neutron thermalization the targets were covered by 6 cm paraffin moderator. Neutron multiplicity distributions were studied inside and on the moderator surface. Comparison of SSNTDs results were made for thermal-epithermal neutrons with sup 1 sup 3 sup 9 La activation method as well as with Dubna DCM/CEM code. Discussion including previous sup 1 sup 2 C results are given.

  2. Neutron flux determination at the IPR-R1 Triga Mark I neutron beam extractor

    International Nuclear Information System (INIS)

    Zangirolami, Dante Marco; Maretti Junior, Fausto; Ferreira, Andrea Vidal

    2009-01-01

    The IPR-R1 Triga Mark I Reactor located at the CDTN/CNEN, Belo Horizonte, Brazil, has been operating since November of 1960. In this work, measurements of thermal and epithermal neutron flux along the IPR-R1 neutron beam extractor were performed by neutron activation of reference materials using the two foils method. The obtained results were compared with results from two previous works: an experimental measurement done in a previous reactor core configuration and a numerical work made by Monte Carlo simulation using the actual reactor core configuration. The main purpose of this work is to update the measured data to the actual reactor core configuration. (author)

  3. Miniature Neutron-Alpha Activation Spectrometer

    Science.gov (United States)

    Rhodes, E.; Goldsten, J.

    2001-01-01

    We are developing a miniature neutron-alpha activation spectrometer for in situ analysis of samples including rocks, fines, ices, and drill cores, suitable for a lander or Rover platform, that would meet the severe mass, power, and environmental constraints of missions to the outer planets. In the neutron-activation mode, a gamma-ray spectrometer will first perform a penetrating scan of soil, ice, and loose material underfoot (depths to 10 cm or more) to identify appropriate samples. Chosen samples will be analyzed in bulk in neutron-activation mode, and then the sample surfaces will be analyzed in alpha-activation mode using Rutherford backscatter and x-ray spectrometers. The instrument will provide sample composition over a wide range of elements, including rock-forming elements (such as Na, Mg, Si, Fe, and Ca), rare earths (Sm and Eu for example), radioactive elements (K, Th, and U), and light elements present in water, ices, and biological materials (mainly H, C, O, and N). The instrument is expected to have a mass of about l kg and to require less than 1 W power. Additional information is contained in the original extended abstract.

  4. Standardization activities of the Euratom Neutron Radiography Working Group

    International Nuclear Information System (INIS)

    Domanus, J.

    1982-06-01

    In 1979 a working group on neutron radiography was formed at Euratom. The purpose of this group is the standardization of neutron radiographic methods in the field of nuclear fuel. Activities of this Neutron Radiography Working Group are revised. Classification of defects revealed by neutron radiography is illustrated in a special atlas. Beam purity and sensitivity indicators are tested together with a special calibration fuel pin. All the Euratom neutron radiography centers will perform comparative neutron radiography with those items. The measuring results obtained, using various measuring aparatus will form the basis to formulate conclusions about the best measuring methods and instruments to be used in that field. Besides the atlas of neutron radiographic findings in light water reactor fuel, the Euratom Neutron Radiogrphy Working Group has published a neutron radiography handbook in which the neutron radiography installations in the European Community are also described. (author)

  5. Applications of neutron activation analysis technique

    International Nuclear Information System (INIS)

    Jonah, S. A.

    2000-07-01

    The technique was developed as far back as 1936 by G. Hevesy and H. Levy for the analysis of Dy using an isotopic source. Approximately 40 elements can be analyzed by instrumental neutron activation analysis (INNA) technique with neutrons from a nuclear reactor. By applying radiochemical separation, the number of elements that can be analysed may be increased to almost 70. Compared with other analytical methods used in environmental and industrial research, NAA has some unique features. These are multi-element capability, rapidity, reproducibility of results, complementarity to other methods, freedom from analytical blank and independency of chemical state of elements. There are several types of neutron sources namely: nuclear reactors, accelerator-based and radioisotope-based sources, but nuclear reactors with high fluxes of neutrons from the fission of 235 U give the most intense irradiation, and hence the highest available sensitivities for NAA. In this paper, the applications of NAA of socio-economic importance are discussed. The benefits of using NAA and related nuclear techniques for on-line applications in industrial process control are highlighted. A brief description of the NAA set-ups at CERT is enumerated. Finally, NAA is compared with other leading analytical techniques

  6. Neutron activation analysis using TRIGA

    International Nuclear Information System (INIS)

    Byrne, A.R.

    1972-01-01

    Activation analysis with TRIGA MARK II is the main part of the work of the nuclear Chemistry Section at the Institute. A major part of the effort in this field is concerned with the determination of trace elements at the micro and nanogram level in a wide variety of materials, and with the development of new methods, (or the adaptation of known methods,) applicable to these determinations. In particular, specific and group radiochemical separations are studied

  7. Opportunities for innovation in neutron activation analysis

    International Nuclear Information System (INIS)

    Peter Bode

    2012-01-01

    Neutron activation laboratories worldwide are at a turning point at which new staff has to be found for the retiring pioneers from the 1960s-1970s. A scientific career in a well-understood technique, often characterized as 'mature' may only be attractive to young scientists if still challenges for further improvement and inspiring new applications can be offered. The strengths and weaknesses of neutron activation analysis (NAA) are revisited to identify opportunities for innovation. Position-sensitive detection of elements in large samples, Monte Carlo calculations replacing the use of standards, use of scintillator detectors and new deconvolution techniques for increasing the sensitivity are examples of challenging new roads in NAA. Material science provides challenges for the application of NAA in both bulk samples, ultrathin layers and ultrapure materials. (author)

  8. Neutron Activation Analysis with k0 standardisation

    International Nuclear Information System (INIS)

    Pomme, S.

    1998-01-01

    The objectives of the research are: (1) to develop and implement the k0 standardisation method for neutron activation analysis in close collaboration with scientific partners; (2) to exploit fully the inherent qualities of NAA such as accuracy, traceability, and multi-element offer complete services in health-physics measurements according to international quality standards, (2) to improve continuously these measurement techniques and to follow up international recommendations and legislation concerning the surveillance of workers; (3) to support and advise nuclear and non-nuclear industry on problems of radioactive contamination. Achievements in 1997 related to gamma spectrometry, whole-body counting, beta and alpha spectrometry, dosimetry, radon measurements, calibration, instrumentation, and neutron activation analysis are described

  9. Neutron activation analysis of monomineral fractions

    International Nuclear Information System (INIS)

    Drykhin, V.I.; Belen'kij, B.V.; Voinkov, D.M.; Il'yasova, K.I.; Lejpinskaya, D.I.; Nedostyp, T.V.

    1977-01-01

    The results are described of the development of an instrumental neutron activation analysis (INAA) of monomineral sulfides (pyrites, pyrrhotites, chalcopyrites and others), quartzites and other minerals, the technique being intended for geochemical investigations. For a multi-element INAA of monomineral sulfides, the optimum irradiation time in a flux of 10 12 to 1.3x10 13 n/cm 2 (neutron field of a nuclear reactor) is 20 to 40 hours, thus ensuring a reliable determination of a great number of elements not lower than 10 -4 %. The time of the induced activity for determining indium in sulfides is 0.5 to 3 min. The actual sensitivity of the method is 10 -4 %. A sensitivity with respect to gold of 0.01 g/t was attained in monominerals after an irradiation of up to 5 min

  10. Neutron activation analysis in archaeological chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Harbottle, G [Brookhaven National Lab., Upton, NY (United States)

    1990-01-01

    There is a long history of the application of chemical analysis to archaeological problems, extending to the last years of the 18th century. The nuclear-age technique of neutron activation analysis, permitting the simultaneous, sensitive, non-destructive estimation of many elements in an archaeological specimen, has found wide application. Important advances have been made, using this technique, in locating the origins of archaeological artifacts such as ceramics, metals, obsidian and semiprecious stones, among other articles of ancient ritual and commerce. In addition, the technique of neutron activation analysis has proved to be almost ideal in studies tracing the development of ancient technologies such as glass-making and smelting. In the future, the development of data banks of analyses of archaeological materials should provide an excellent new tool in studies of prehistory.

  11. Neutron activation analysis in archaeological chemistry

    International Nuclear Information System (INIS)

    Harbottle, G.

    1990-01-01

    There is a long history of the application of chemical analysis to archaeological problems, extending to the last years of the 18th century. The nuclear-age technique of neutron activation analysis, permitting the simultaneous, sensitive, non-destructive estimation of many elements in an archaeological specimen, has found wide application. Important advantages have been made, using this technique, in locating the origins of archaeological artifacts such as ceramics, metals, obsidian and semiprecious stones, among other articles of ancient ritual and commerce. In addition, the technique of neutron activation analysis has proved to be almost ideal in studies tracing the development of ancient technologies such as glass-making and smelting. In the future, the development of data banks of analyses of archaeological materials should provide an excellent new tool in studies of prehistory. (orig.)

  12. Physical basis for prompt-neutron activation analysis

    International Nuclear Information System (INIS)

    Chrien, R.E.

    1982-01-01

    The technique called prompt ν-ray neutron activation analysis has been applied to rapid materials analysis. The radiation following the neutron radiation capture is prompt in the sense that the nuclear decay time is on the order of 10 - 15 second, and thus the technique is not strictly activation, but should be called radiation neutron capture spectroscopy or neutron capture ν-ray spectroscopy. This paper reviews the following: sources and detectors, theory of radiative capture, nonstatistical capture, giant dipole resonance, fast neutron capture, and thermal neutron capture ν-ray spectra. 14 figures

  13. Particulate matter and neutron activation analysis

    International Nuclear Information System (INIS)

    Otoshi, Tsunehiko

    2003-01-01

    In these years, economy of East Asian region is rapidly growing, and countries in this region are facing serious environmental problems. Neutron activation analysis is known as one of high-sensitive analytical method for multi elements. And it is a useful tool for environmental research, particularly for the study on atmospheric particulate matter that consists of various constituents. Elemental concentration represents status of air, such as emission of heavy metals from industries and municipal incinerators, transportation of soil derived elements more than thousands of kilometers, and so on. These monitoring data obtained by neutron activation analysis can be a cue to evaluate environment problems. Japanese government launched National Air Surveillance Network (NASN) employing neutron activation analysis in 1974, and the data has been accumulated at about twenty sampling sites. As a result of mitigation measure of air pollution sources, concentrations of elements that have anthropogenic sources decreased particularly at the beginning of the monitoring period. However, even now, concentrations of these anthropogenic elements reflect the characteristics of each sampling site, e.g. industrial/urban, rural, and remote. Soil derived elements have a seasonal variation because of the contribution of continental dust transported by strong westerly winds prevailing in winter and spring season. The health effects associated with trace elements in particulate matter have not been well characterized. However, there is increasing evidence that particulate air pollution, especially fine portion of particles in many different cities is associated with acute mortality. Neutron activation analysis is also expected to provide useful information to this new study field related to human exposures and health risk. (author)

  14. Research reactor operations for neutron activation analysis

    International Nuclear Information System (INIS)

    Tv'ehlov, Yu.

    2002-01-01

    The IAEA Special Manual devoted to quality control during neutron activation analysis (NAA) on research and test reactors is discussed. Three parts of the publication involve presentation of common rules for performance of NAA, quantitative and qualitative analyses, statistic and systematic errors, safety regulations and radioactive waste management. Besides, the publication contains practical manual for the performance of NAA, and examples of different NAA regulating registration forms are presented [ru

  15. Reactor neutron activation analysis of industrial materials

    International Nuclear Information System (INIS)

    Niese, S.

    1983-01-01

    The specific application of neutron activation analysis (n.a.a.) for industrial materials is demonstrated by the determination of impurities in BeO, Al, Si, Cu, Ge, GaP, GaAs, steel, and irradiated uranium. A group scheme gives an orientation about the possibilities of n.a.a. The use of different standards, methods for the measurement of low radioactivities and errors caused by recoil reaction and radiation stimulated diffusion are discussed. (author)

  16. Boron Neutron Capture Therapy activity of diffused tumors at TRIGA Mark II in Pavia

    Energy Technology Data Exchange (ETDEWEB)

    Bortolussi, S.; Stella, S.; De Bari, A.; Altieri, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy)]|[National Institute of Nuclear Physics (INFN), Pavia (Italy); Bruschi, P.; Bakeine, J.G. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Clerici, A.; Ferrari, C.; Zonta, C.; Zonta, A. [Department of Surgery, University of Pavia, Pavia (Italy); Nano, R. [Department of Animal Biology, University of Pavia, Pavia (Italy)

    2008-10-29

    The Boron neutron Capture Therapy research in Pavia has a long tradition: it begun more than 20 years ago at the TRIGA Mark II reactor of the University. A technique for the treatment of the hepatic metastases was developed, consisting in explanting the liver treated with {sup 10}B, irradiating it in the thermal column of the reactor, and re-implanting the organ in the patient. In the last years, the possibility of applying BNCT to the lung tumours using epithermal collimated neutron beams and without explanting the organ, is being explored. The principal obtained results of the BNCT research will be presented, with particular emphasis on the following aspects: a) the project of a new thermal column configuration to make the thermal neutron flux more uniform inside the explanted liver, b) the Monte Carlo study by means of the MCNP code of the thermal neutron flux distribution inside a patient's thorax irradiated with epithermal neutrons, and c) the measurement of the boron concentration in tissues by (n,{alpha}) spectroscopy and neutron autoradiography. (authors)

  17. Boron Neutron Capture Therapy activity of diffused tumors at TRIGA Mark II in Pavia

    International Nuclear Information System (INIS)

    Bortolussi, S.; Stella, S.; De Bari, A.; Altieri, S.; Bruschi, P.; Bakeine, J.G.; Clerici, A.; Ferrari, C.; Zonta, C.; Zonta, A.; Nano, R.

    2008-01-01

    The Boron neutron Capture Therapy research in Pavia has a long tradition: it begun more than 20 years ago at the TRIGA Mark II reactor of the University. A technique for the treatment of the hepatic metastases was developed, consisting in explanting the liver treated with 10 B, irradiating it in the thermal column of the reactor, and re-implanting the organ in the patient. In the last years, the possibility of applying BNCT to the lung tumours using epithermal collimated neutron beams and without explanting the organ, is being explored. The principal obtained results of the BNCT research will be presented, with particular emphasis on the following aspects: a) the project of a new thermal column configuration to make the thermal neutron flux more uniform inside the explanted liver, b) the Monte Carlo study by means of the MCNP code of the thermal neutron flux distribution inside a patient's thorax irradiated with epithermal neutrons, and c) the measurement of the boron concentration in tissues by (n,α) spectroscopy and neutron autoradiography. (authors)

  18. Neutron activation analysis of biological substances

    International Nuclear Information System (INIS)

    Ordogh, M.

    1978-08-01

    A Bowen cabbage sample was used as a reference material for the neutron activation studies, and the method was checked by the analysis of other biological substances (blood or serum etc.). For nondestructive measurements also some non-trace elements were determined in order to decide whether the activation analysis is a useful means for such measurements. The new activation analysis procedure was used for biomedical studies as, e.g., for trace element determination in body fluids, and for the analysis of inorganic components in air samples. (R.P.)

  19. Applications of neutrons for laboratory and industrial activation analysis problems

    International Nuclear Information System (INIS)

    Szabo, Elek; Bakos, Laszlo

    1986-01-01

    This chapter presents some particular applications and case studies of neutrons in activation analysis for research and industrial development purposes. The reactor neutrons have been applied in Hungarian laboratories for semiconductor research, for analysis of geological (lunar) samples, and for a special comparator measurement of samples. Some industrial applications of neutron generator and sealed sources for analytical problems are presented. Finally, prompt neutron activation analysis is outlined briefly. (R.P.)

  20. A development and integration of the concentration database for relative method, k0 method and absolute method in instrumental neutron activation analysis using Microsoft Access

    International Nuclear Information System (INIS)

    Hoh Siew Sin

    2012-01-01

    Instrumental Neutron Activation Analysis (INAA) is offen used to determine and calculate the concentration of an element in the sample by the National University of Malaysia, especially students of Nuclear Science Program. The lack of a database service leads consumers to take longer time to calculate the concentration of an element in the sample. This is because we are more dependent on software that is developed by foreign researchers which are costly. To overcome this problem, a study has been carried out to build an INAA database software. The objective of this study is to build a database software that help the users of INAA in Relative Method and Absolute Method for calculating the element concentration in the sample using Microsoft Excel 2010 and Microsoft Access 2010. The study also integrates k 0 data, k 0 Concent and k 0 -Westcott to execute and complete the system. After the integration, a study was conducted to test the effectiveness of the database software by comparing the concentrations between the experiments and in the database. Triple Bare Monitor Zr-Au and Cr-Mo-Au were used in Abs-INAA as monitor to determine the thermal to epithermal neutron flux ratio (f). Calculations involved in determining the concentration are the net peak area (N p ), the measurement time (t m ), the irradiation time (t irr ), k-factor (k), thermal to epithermal neutron flux ratio (f), the parameters of the neutron flux distribution epithermal (α) and detection efficiency (ε p ). For Com-INAA databases, reference material IAEA-375 Soil was used to calculate the concentration of elements in the sample. CRM, SRM are also used in this database. After the INAA database integration, a verification process was to examine the effectiveness of the Abs-INAA was carried out by comparing the sample concentration between the in database and the experiment. The result of the experimental concentration value of INAA database software performed with high accuracy and precision. ICC

  1. Neutron, gamma and Roentgen fluorescent activation analysis of hair of children suffering from bronchial asthma

    International Nuclear Information System (INIS)

    Alekseeva, O.A.; Belov, A.G.; Frontasyeva, M.V.; Gundorina, S.F.; Gustova, M.V.; Kusmenko, L.G.; Perelygin, V.P.; Zaverioukha, O.S.

    2001-01-01

    The aim of present study was the multiparametric study of dangerous microelements content in the hair of children under school and primary school age which included 12 children ill with bronchial asthma and 11 control group persons in the town of Troitsk, Moscow Region. The hair specimens with weight 15-220 mg were analysed with the application of epithermal neutron activation analysis conducted at experimental installation REGATA and neutron source-unique Pulsed Fast Reactor IBR-2, with the application of combined gamma-neutron irradiation at Microtron MT-25 and with Roentgen Fluorescence Analysis device of JINR. The data of elements content in hair were obtained with solid state track detectors and semiconductor electronic spectrometers. The solid state track detectors provide the determination of U, Th, Bi and Be elements at the level of sensitivity up to 10 -8 -10 -9 g/g. These data were compared with more representative information about dangerous microelements concentration obtained with NAA and RFA analyses. The obtained concentrations of most elements vary in a wide range, but in agreement with the known data. The highest degree of element dispersion was observed for U, Th, Pb, I, Br, Sb, Co, K and Be (the radiation coefficient was higher than 100-200%). The presented analysis of results shows that in the clinical picture there is some proved correlation between an increased content of some element in hair and symptoms of their accumulation in the organism of ill children, the revelation of which is the basic idea of our examination

  2. Uncertainty Assessments in Fast Neutron Activation Analysis

    International Nuclear Information System (INIS)

    W. D. James; R. Zeisler

    2000-01-01

    Fast neutron activation analysis (FNAA) carried out with the use of small accelerator-based neutron generators is routinely used for major/minor element determinations in industry, mineral and petroleum exploration, and to some extent in research. While the method shares many of the operational procedures and therefore errors inherent to conventional thermal neutron activation analysis, its unique implementation gives rise to additional specific concerns that can result in errors or increased uncertainties of measured quantities. The authors were involved in a recent effort to evaluate irreversible incorporation of oxygen into a standard reference material (SRM) by direct measurement of oxygen by FNAA. That project required determination of oxygen in bottles of the SRM stored in varying environmental conditions and a comparison of the results. We recognized the need to accurately describe the total uncertainty of the measurements to accurately characterize any differences in the resulting average concentrations. It is our intent here to discuss the breadth of potential parameters that have the potential to contribute to the random and nonrandom errors of the method and provide estimates of the magnitude of uncertainty introduced. In addition, we will discuss the steps taken in this recent FNAA project to control quality, assess the uncertainty of the measurements, and evaluate results based on the statistical reproducibility

  3. Neutron activation analysis of high purity substances

    International Nuclear Information System (INIS)

    Gil'bert, Eh.N.

    1987-01-01

    Peculiarities of neutron-activation analysis (NAA) of high purity substances are considered. Simultaneous determination of a wide series of elements, high sensitivity (the lower bound of determined contents 10 -9 -10 -10 %), high selectivity and accuracy (Sr=0.10-0.15, and may be decreased up to 0.001), possibility of analysis of the samples from several micrograms to hundreds of grams, simplicity of calibration may be thought NAA advantages. Questions of accounting of NAA systematic errors associated with the neutron flux screening by the analysed matrix and with production of radionuclides of determined elements from accompanying elements according to concurrent nuclear reactions, as well as accounting of errors due to self-absorption of recorded radiation by compact samples, are considered

  4. Neutron activation analysis of high purity tellurium

    International Nuclear Information System (INIS)

    Gil'bert, Eh.N.; Verevkin, G.V.; Obrazovskij, E.G.; Shatskaya, S.S.

    1980-01-01

    A scheme of neutron activation analysis of high purity tellurium is developed. Weighed amount of Te (0.5 g) is irradiated for 20-40 hr in the flux of 2x10 13 neutron/(cm 2 xs). After decomposition of the sample impurities of gold and palladium are determined by the extraction with organic sulphides. Tellurium separation from the remaining impurities is carried out by the extraction with monothiobenzoic acid from weakly acidic HCl solutions in the presence of iodide-ions, suppressing silver extraction. Remaining impurity elements in the refined product are determined γ-spectrometrically. The method allows to determine 34 impurities with determination limits 10 -6 -10 -11 g

  5. Development of an anthropomorfic simulator for simulation and measurements of neutron dose and flux the facility for BNCT studies

    International Nuclear Information System (INIS)

    Muniz, Rafael Oliveira Rondon

    2010-01-01

    IPEN facility for researches in BNCT (Boron Neutron Capture Therapy) uses IEA-R1 reactor's irradiation channel number 3, where there is a mixed radiation field - neutrons and gamma. The researches in progress require the radiation fields, in the position of the irradiation of sample, to have in its composition maximized thermal neutrons component and minimized, fast and epithermal neutron flux and gamma radiation. This work was developed with the objective of evaluating whether the present radiation field in the facility is suitable for BNCT researches. In order to achieve this objective, a methodology for the dosimetry of thermal neutrons and gamma radiation in mixed fields of high doses, which was not available in IPEN, was implemented in the Center of Nuclear Engineering of IPEN, by using thermoluminescent dosimeters - TLDs 400, 600 and 700. For the measurements of thermal and epithermal neutron flux, activation detectors of gold were used applying the cadmium ratio technique. A cylindrical phantom composed by acrylic discs was developed and tested in the facility and the DOT 3.5. computational code was used in order to obtain theoretical values of neutron flux and the dose along phantom. In the position corresponding to about half the length of the cylinder of the phantom, the following values were obtained: thermal neutron flux (2,52 ± 0,06).10 8 n/cm 2 s, epithermal neutron flux (6,17 ± 0,26).10 7 .10 6 n/cm 2 s, absorbed dose due to thermal neutrons (4,2 ± 1,8)Gy and (10,1 ± 1,3)Gy due to gamma radiation. The obtained values show that the fluxes of thermal and epithermal neutrons flux are appropriate for studies in BNCT, however, the dose due to gamma radiation is high, indicating that the facility should be improved. (author)

  6. Compton suppression method and epithermal NAA in the determination of nutrients and heavy metals in Nigerian food and beverages

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Y.A., E-mail: yaahmed1@gmail.co [Reactor Engineering Section, Centre for Energy Research and Training, Ahmadu Bello University, Zaria (Nigeria); Nuclear Engineering Teaching Laboratory, University of Texas at Austin, Austin, TX 78758 (United States); Landsberger, S.; O' Kelly, D.J.; Braisted, J. [Nuclear Engineering Teaching Laboratory, University of Texas at Austin, Austin, TX 78758 (United States); Gabdo, H. [Physics Department, Federal College of Education, Yola (Nigeria); Ewa, I.O.B.; Umar, I.M.; Funtua, I.I. [Reactor Engineering Section, Centre for Energy Research and Training, Ahmadu Bello University, Zaria (Nigeria)

    2010-10-15

    We used in this study Compton suppression method and epithermal neutron activation analysis to determine the concentration of nutrients and heavy metals in Nigerian food and beverages. The work was performed at the University of Texas TRIGA Reactor by short, medium, and long irradiation protocols, using thermal flux of 1.4x10{sup 12} n cm{sup -2} s{sup -1} and epithermal flux of 1.4x10{sup 11} n cm{sup -2} s{sup -1}. Application of Compton suppression method has reduced interferences from Compton scattered photons thereby allowing easy evaluation of Na, Cl, Ca, Cu, Mn, Mg, Co, Cr, Rb, Fe, and Se. The epithermal NAA method has enabled determination of Cd, As, Ba, Sr, Br, I, and V with little turn-around time. Quality Control and Quality Assurance of the method was tested by analyzing four Standard Reference Materials (non-fat powdered milk, apple leaves, citrus leaves, and peach leaves) obtained from National Institute for Standards and Technology. Our results show that sorghum, millet, and maize have high values of Zn, Mn, Fe, low values of Cd, As, and Se. Powdered milks, rice, beans, and soybeans were found to have moderate amounts of all the elements. Tobacco recorded high content of Cd, Mn, and As, whereas tea, tsobo leaves, Baobab leaves, and okro seed have more As values than others. However, biscuits, macaroni, spaghetti, and noodles show lower concentrations of all the elements. The distribution of these nutrients and heavy metals in these food and beverages shows the need to fortify biscuits and pastas with micro and macro-nutrients and reduce the use of tobacco, tea, tsobo leaves, Baobab leaves, and Okro seed to avoid intake of heavy elements.

  7. Compton suppression method and epithermal NAA in the determination of nutrients and heavy metals in Nigerian food and beverages.

    Science.gov (United States)

    Ahmed, Y A; Landsberger, S; O'Kelly, D J; Braisted, J; Gabdo, H; Ewa, I O B; Umar, I M; Funtua, I I

    2010-10-01

    We used in this study Compton suppression method and epithermal neutron activation analysis to determine the concentration of nutrients and heavy metals in Nigerian food and beverages. The work was performed at the University of Texas TRIGA Reactor by short, medium, and long irradiation protocols, using thermal flux of 1.4x10(12)n cm(-2)s(-1) and epithermal flux of 1.4x10(11)n cm(-2)s(-1). Application of Compton suppression method has reduced interferences from Compton scattered photons thereby allowing easy evaluation of Na, Cl, Ca, Cu, Mn, Mg, Co, Cr, Rb, Fe, and Se. The epithermal NAA method has enabled determination of Cd, As, Ba, Sr, Br, I, and V with little turn-around time. Quality Control and Quality Assurance of the method was tested by analyzing four Standard Reference Materials (non-fat powdered milk, apple leaves, citrus leaves, and peach leaves) obtained from National Institute for Standards and Technology. Our results show that sorghum, millet, and maize have high values of Zn, Mn, Fe, low values of Cd, As, and Se. Powdered milks, rice, beans, and soybeans were found to have moderate amounts of all the elements. Tobacco recorded high content of Cd, Mn, and As, whereas tea, tsobo leaves, Baobab leaves, and okro seed have more As values than others. However, biscuits, macaroni, spaghetti, and noodles show lower concentrations of all the elements. The distribution of these nutrients and heavy metals in these food and beverages shows the need to fortify biscuits and pastas with micro and macro-nutrients and reduce the use of tobacco, tea, tsobo leaves, Baobab leaves, and Okro seed to avoid intake of heavy elements. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. Compton suppression method and epithermal NAA in the determination of nutrients and heavy metals in Nigerian food and beverages

    International Nuclear Information System (INIS)

    Ahmed, Y.A.; Landsberger, S.; O'Kelly, D.J.; Braisted, J.; Gabdo, H.; Ewa, I.O.B.; Umar, I.M.; Funtua, I.I.

    2010-01-01

    We used in this study Compton suppression method and epithermal neutron activation analysis to determine the concentration of nutrients and heavy metals in Nigerian food and beverages. The work was performed at the University of Texas TRIGA Reactor by short, medium, and long irradiation protocols, using thermal flux of 1.4x10 12 n cm -2 s -1 and epithermal flux of 1.4x10 11 n cm -2 s -1 . Application of Compton suppression method has reduced interferences from Compton scattered photons thereby allowing easy evaluation of Na, Cl, Ca, Cu, Mn, Mg, Co, Cr, Rb, Fe, and Se. The epithermal NAA method has enabled determination of Cd, As, Ba, Sr, Br, I, and V with little turn-around time. Quality Control and Quality Assurance of the method was tested by analyzing four Standard Reference Materials (non-fat powdered milk, apple leaves, citrus leaves, and peach leaves) obtained from National Institute for Standards and Technology. Our results show that sorghum, millet, and maize have high values of Zn, Mn, Fe, low values of Cd, As, and Se. Powdered milks, rice, beans, and soybeans were found to have moderate amounts of all the elements. Tobacco recorded high content of Cd, Mn, and As, whereas tea, tsobo leaves, Baobab leaves, and okro seed have more As values than others. However, biscuits, macaroni, spaghetti, and noodles show lower concentrations of all the elements. The distribution of these nutrients and heavy metals in these food and beverages shows the need to fortify biscuits and pastas with micro and macro-nutrients and reduce the use of tobacco, tea, tsobo leaves, Baobab leaves, and Okro seed to avoid intake of heavy elements.

  9. Instrumental neutron activation analysis of biological samples

    International Nuclear Information System (INIS)

    Guinn, V.P.; Gavrilas, M.

    1990-01-01

    The elemental compositions of 18 biological reference materials have been processed, for 14 stepped combinations of irradiation/decay/counting times, by the INAA Advance Prediction Computer Program. The 18 materials studied include 11 plant materials, 5 animal materials, and 2 other biological materials. Of these 18 materials, 14 are NBS Standard Reference Materials and four are IAEA reference materials. Overall, the results show that a mean of 52% of the input elements can be determined to a relative standard deviation of ±10% or better by reactor flux (thermal plus epithermal) INAA

  10. Neutron activation analysis of automobile exhaust pollutants

    International Nuclear Information System (INIS)

    Oakes, T.W.; Furr, A.K.; Adair, D.J.; Parkinson, T.F.

    1977-01-01

    An approximation of the distribution of lead particulate from vehicular exhausts is given. Soil and grass (Poa trivialis) samples were collected at five-foot intervals from the roadside out to 300 feet, at ten-foot intervals from 300 to 350 feet, and at 25-foot intervals from 350 to 600 feet. All samples were irradiated twice: once for a brief period of from 10 to 120 seconds and later for periods of from 6 to 8 hours. The short irradiations were at a thermal neutron flux of 1.2x10 12 ncm -2 sec -1 (decay time=1 min, counting time=8 min). The long irradiations were at a thermal neutron flux of 1.3x10 12 ncm -2 sec -1 , and the samples counted twice at decay intervals of two days and twelve days. The counting intervals were one hour. The spectra were stored on magnetic tape for processing by an IBM 370/158 computer. This initial neutron-activation analysis study has shown that there is an extremely detailed pattern of the effluent from vehicular highway traffic which is strongly affected by micrometeorological conditions. In order to detect these patterns it is necessary to use a very compact sample grid with every possible precaution taken to ensure sample homogeneity and cleanliness. A possibility of elevated levels of pollution may exist at considerable distances from the highway, perhaps even greater than at the immediate roadside. (T.G.)

  11. Study of spectral response of a neutron filter. Design of a method to adjust spectra; Etude des moyens de conditionnement de la reponse spectrale d'un filtre a neutrons. Mise au point d'une methode d'ajustement rapide de spectre

    Energy Technology Data Exchange (ETDEWEB)

    Colomb-Dolci, F. [Universite Louis Pasteur, 67 - Strasbourg (France)

    1999-02-01

    The first part of this thesis describes an experimental method which intends to determine a neutron spectrum in the epithermal range [1 eV -10 keV]. Based on measurements of reaction rates provided by activation foils, it gives flux level in each energy range corresponding to each probe. This method can be used in any reactor location or in a neutron beam. It can determine scepter on eight energy groups, five groups in the epithermal range. The second part of this thesis presents a study of an epithermal neutron beam design, in the frame of Neutron Capture Therapy. A beam tube was specially built to test filters made up of different materials. Its geometry was designed to favour epithermal neutron crossing and to cut thermal and fast neutrons. A code scheme was validated to simulate the device response with a Monte Carlo code. Measurements were made at ISIS reactor and experimental spectra were compared to calculated ones. This validated code scheme was used to simulate different materials usable as shields in the tube. A study of these shields is presented at the end of this thesis. (author)

  12. Practical considerations in instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Ahmad, N.

    2001-01-01

    Activation analysis is a technique of elemental analysis based on the measurement of characteristics radiation from radionuclides formed directly or indirectly by activation. The activation can be induced by bombarding the material with neutrons or charged particles or gamma rays. This is a well-accepted analytical technique for the determination of composition of complex materials. This technique is also sensitive at trace levels and is almost free from analytical interferences of matrix. It is used for multi-elemental determination in rocks, minerals, alloys, biological materials, geological samples, non-destructive analysis of materials and environmental samples such as water, air particulate matter, plants, soil, sediments and diets. This method is also used for production and measurements of radioisotopes in materials of known composition, for example, when radioactivation is used for nuclear reaction studies, for flux and beam intensity measurements for trace experiments and process quality control. In this article the parameters affecting the sensitivity of instrumental neutron activation analysis are briefly discussed. (author)

  13. Neutron activation analysis of geological material

    International Nuclear Information System (INIS)

    Greef, G.J.

    1977-05-01

    In neutron activation analysis the precision and accuracy of results are often misleading, since only the statistical errors which accompany the measuring of radioactivity are taken into consideration. Several other factors can, however, also influence precision and accuracy. It was found that a geological sample was contaminated with the construction material of the mill in which it had been pulverised. Several geometrical differences which could possibly play a role were also investigated. Impurities in the irradiation containers affect the determination of some elements in the samples; the contamination materials in quarts irradiation tubes were determined. The flux gradients which may effect the relative activities of the samples and standards were measured. Suitable standards are necessary to ensure accurate analyses of geological material. Available natural standards were critically evaluated and several methods were investigated by which synthetic standards may be prepared. In order to accurately determine gallium, lanthanum and samarium by means of neutron activation analysis, sodium first had to be removed. After irradiation the sample was dissolved in a mixture of acids and the soidium absorbed from the solution on a hydrated antimony pentoxide column. Gallium, lanthanum and samarium activities were measured by means of precision gamma-spectrometry

  14. New generation non-stationary portable neutron generators for biophysical applications of Neutron Activation Analysis.

    Science.gov (United States)

    Marchese, N; Cannuli, A; Caccamo, M T; Pace, C

    2017-01-01

    Neutron sources are increasingly employed in a wide range of research fields. For some specific purposes an alternative to existing large-scale neutron scattering facilities, can be offered by the new generation of portable neutron devices. This review reports an overview for such recently available neutron generators mainly addressed to biophysics applications with specific reference to portable non-stationary neutron generators applied in Neutron Activation Analysis (NAA). The review reports a description of a typical portable neutron generator set-up addressed to biophysics applications. New generation portable neutron devices, for some specific applications, can constitute an alternative to existing large-scale neutron scattering facilities. Deuterium-Deuterium pulsed neutron sources able to generate 2.5MeV neutrons, with a neutron yield of 1.0×10 6 n/s, a pulse rate of 250Hz to 20kHz and a duty factor varying from 5% to 100%, when combined with solid-state photon detectors, show that this kind of compact devices allow rapid and user-friendly elemental analysis. "This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo". Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Determination of the sodium, aluminium, potassium, manganese, magnesium, bromine, cadmium and chlorine concentration values in the whole blood samples of human cancer using neutron activation analysis facility of the second Egyptian research reactor

    Directory of Open Access Journals (Sweden)

    N. F. Soliman

    2010-06-01

    Full Text Available Neutron activation analysis (NAA using the Second Egyptian Research Reactor (ETRR-2 has been utilized to analyze whole blood samples. The National Cancer Institute of Egypt provided us with 18 blood samples (11 breast, 2 prostate, 2 colon, 1 pancreatic, 1 ovarian and a random sample of normal person to estimate the concentration values of Sodium, Aluminium, Potassium, Manganese, Magnesium, Bromine, Chlorine. The pneumatic irradiation rabbit system (PIRS built in the vertical thermal column of the ETRR-2 reactor is used for short time irradiation at constant power. Elemental concentrations were estimated from measurements of the gamma-ray spectra of the product short lived isotopes in the samples. The calculated thermal to epithermal neutron flux ratio was found to be 196 at irradiation position. The tabulated concentrations were calculated by using k0-neutron activation analysis (k0NAA standardization method.

  16. Radioactive waste characterisation by neutron activation

    International Nuclear Information System (INIS)

    Nicol, Tangi

    2016-01-01

    Nuclear activities produce radioactive wastes classified following their radioactive level and decay time. an accurate characterization is necessary for efficient classification and management. Medium and high level wastes containing long lived radioactive isotopes will be stored in deep geological storage for hundreds of thousands years. at the end of this period, it is essential to ensure that the wastes do not represent any risk for humans and environment, not only from radioactive point of view, but also from stable toxic chemicals. This PhD thesis concerns the characterization of toxic chemicals and nuclear material in radioactive waste, by using neutron activation analysis, in the frame of collaboration between the Nuclear Measurement Laboratory of CEA Cadarache, France, and the Institute of Nuclear Waste Management and Reactor Safety of the research center, FZJ (Forschungszentrum Juelich GmbH), Germany. The first study is about the validation of the numerical model of the neutron activation cell MEDINA (FZJ), using MCNP Monte Carlo transport code. Simulations and measurements of prompt capture gamma rays from small samples measured in MEDINA have been compared for a number of elements of interest (beryllium, aluminum, chlorine, copper, selenium, strontium, and tantalum). The comparison was performed using different nuclear databases, resulting in satisfactory agreement and validating simulation in view of following studies. Then, the feasibility of fission delayed gamma-ray measurements of "2"3"9Pu and "2"3"5U in 225 L waste drums has been studied, considering bituminized or concrete matrixes representative of wastes produced in France and Germany. The delayed gamma emission yields were first determined from uranium and plutonium metallic samples measurements in REGAIN, the neutron activation cell of LMN, showing satisfactory consistency with published data. The useful delayed gamma signals of "2"3"9Pu and "2"3"5U, homogeneously distributed in the 225 L

  17. Study on the determination of palladium in biological samples by the method of neutron activation analysis

    International Nuclear Information System (INIS)

    Cavalcante, Cassio Queiroz

    2007-01-01

    Palladium is one of platinum group elements present in the nature at very low concentrations. However with the use of this element in the automobile catalyzers Pd became a new pollutant. Besides, Pd has been studied in the preparation of new antitumour drugs. Consequently, there is a need to determine Pd concentrations in biological and environmental samples. This study presents palladium results obtained in the analysis of biological samples and reference materials using instrumental thermal and epithermal neutron activation analysis (INAA and ENAA). The solvent extraction and solid phase extraction separation methods were also applied before ENAA. The samples analyzed in this study were, reference material BCR 723 - Palladium, Platinum and Rhodium in road dust, CCQM-P63 automotive catalyst material of the Proficiency Test and bovine tissue samples containing palladium prepared in the laboratory. Samples and palladium synthetic standard were irradiated at the IEA-R1 nuclear research reactor under thermal neutron flux of about 4 x 10 12 n cm-2 s-1, during a period of 4 and 16 h for INAA and ENAA, respectively. The induced gamma activity of 109 Pd to the sample and standard was measured using a hyper pure Ge detector coupled to a gamma ray spectrometer. The palladium concentration was calculated by comparative method. The gamma ray energy of 109 Pd radioisotope measured was of 88.0 keV, located in a spectrum region of low energy where occurs the interference of X rays, 'Bremsstrahlung' radiations, as well as Compton effect of 24 Na. The pre-separation of palladium from interfering elements by solvent extraction was performed using dimethylglyoxime complexant and chloroform as diluent. In the case of the pre separation procedure using solid reversed phase column, the palladium was retained using N,N-diethyl-N'-benzoyl thiourea complexant and eluted using ethanol. Aliquots of the resulting solutions from the pre-separations, free of interfering elements, were

  18. Neutron activation analysis of medicinal plant extracts

    International Nuclear Information System (INIS)

    Vaz, S.M.; Saiki, M.; Vasconcellos, M.B.A.; Sertie, J.A.A.

    1995-01-01

    Instrumental neutron activation analysis was applied to the determination of the elements Br, Ca, Cl, Cs, Fe, K, La, Mg, Mn, Na, Rb and Zn in medicinal extracts obtained from Centella asiatica, Citrus aurantium L., Achyrolcline satureoides DC, Casearia sylvestris, Solano lycocarpum, Zingiber officinale Roscoe, Solidago microglossa and Stryphnondedron barbatiman plants. The elements Hg and Se were determined using radiochemical separation by means of retention of Se in HMD inorganic exchanger and solvent extraction of Hg by bismuth diethyldithiocarbamate solution. Precision and accuracy of the results were evaluated by analyzing biological reference materials. The therapeutic action of some elements found in plant extracts analyzed is briefly discussed. (author). 15 refs., 5 tabs

  19. Neutron activation analysis of atmospheric aerosol

    International Nuclear Information System (INIS)

    Obrusnik, I.

    1986-01-01

    Neutron activation analysis (NAA) is a modern analytical method well suited for the analysis of atmospheric aerosols. Particular steps of the NAA procedure and especially different types of aerosol sampling and sample preparation for analysis are discussed in detail. Several possible NAA techniques are described and the advantages of a purely instrumental technique with short and long irradiation are pointed out. Important performance characteristics of the NAA method such as precision, accuracy, sensitivity and detection limits are also discussed. Different applications of NAA in environmental studies are reviewed. (author)

  20. Quality assurance in biomedical neutron activation analysis

    International Nuclear Information System (INIS)

    1984-01-01

    The summary report represents an attempt to identify some of the possible sources of error in in vitro neutron activation analysis of trace elements applied to specimens of biomedical origin and to advise on practical means to avoid them. The report is intended as guidance for all involved in analysis, including sample collection and preparation for analysis. All these recommendations constitute part of quality assurance which is here taken to encompass the two concepts - quality control and quality assessment. Quality control is the mechanism established to control errors, while quality assessment is the mechanism used to verify that the analytical procedure is operating within acceptable limits

  1. Neutron activation analysis of atmospheric aerosols

    International Nuclear Information System (INIS)

    Riekstinya, D.V.; Mednis, I.V.; Veveris, O.Eh.

    1987-01-01

    A review of studies by Soviet and foreign authors on radioactivation analysis is presented. Instrumental neutron activation analysis (INAA) techniques have been developed providing the possibility to determine a number of elements in very small portions of aerosols for pollutanless areas of the Earth. Two ways of INAA are presented: with long- and short-living radionuclides. The Antarctic and the Indian Ocean aerosol samples have been analysed for 26 microelements. It has been stated that restrictions of the detection limits attained relate to high proportions of certain elements and their nonhomogeneous distribution in filters. The detection limits can be lowered by the filtered air volume growth per unit of the filter area

  2. Instrumental Neutron Activation Analysis for Human Hair

    International Nuclear Information System (INIS)

    Ratanatongchai, W.; Dharmvanij, W; Chongkum, S.

    1998-01-01

    Hair samples from students aged between 7 to 22 years old were analysed by neutron activation analysis at nuclear research reactor TRR-1.M1. From qualitative analysis of short-lived isotopes, A1, V, Ca, I, Cl, Mn, and Na were found. The quantity of those elements can be classified into three groups. The first group is A1, Ca, Na and Cl with variance less than 10%. The second group is V and I with variance between 10% to 50% and the third group, Mn, two samples have concentration about 12 times higher than the others

  3. Development of neutron activation analysis software

    International Nuclear Information System (INIS)

    Wang Liyu

    1987-10-01

    The software for quantitative neutron activation analysis was developed to run under the MS/DOS operating system. The programmes of the IBM/SPAN include: spectra file transfer from and to a Canberra Series 35 multichannel analyzer, spectrum evaluation routines, calibration subprogrammes, and quantitative analysis. The programmes for spectrum analysis include fitting routine for separation of multiple lines by reproducing the peak shape with a combination of Gaussian and exponential terms. The programmes were tested on an IBM/AT-compatible computer. The programmes and the sources are available costfree for the IAEA projects of Technical Cooperation. 7 refs, 3 figs

  4. Neutron activation analysis of biological material

    International Nuclear Information System (INIS)

    Kucera, J.; Simkova, M.; Obrusnik, I.

    1985-01-01

    The possibilities are briefly summed up of usino. NAA (neutron activation analysis) for determining element traces in foodstuffs and their intake by organisms, for monitoring changes in the content of important trace elements in tissues and body fluids owing to environmental pollution, for verifying the results of other analytical techniques and for certifying the content of element traces in reference materials. Examples are given of the use of NAA, and the results are summed up of the determination of Cd, Mn and Zn in biological reference materials NBS SRM-1577, Bovine Liver, Bowen's Kale, IAEA Milk Powder A-11 and IAEA Animal Muscle H-4. (E.S.)

  5. Toxicological applications of neutron-activation analysis

    International Nuclear Information System (INIS)

    Cross, J.D.; Dale, I.M.; Smith, H.

    1975-01-01

    Thermal neutron-activation analysis is recognised as a useful tool for trace element studies in toxicology. This paper describes some recent applications of the technique to three elements when ingested by people in excess of normal intake Two of the elements (copper and chromium) are essential to life and one (bromine) is as yet unclassified. Three deaths were investiagted and trace element levels compared with normal levels from healthy subjects in the same geographical area who had died as a result of violence. (author)

  6. Support system for Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Sasajima, Fumio; Ohtomo, Akitoshi; Sakurai, Fumio; Onizawa, Koji

    1999-01-01

    In the research reactor of JAERI, the Neutron Activation Analysis (NAA) has been utilized as a major part of an irradiation usage. To utilize NAA, research participants are always required to learn necessary technique. Therefore, we started to examine a support system that will enable to carry out INAA easily even by beginners. The system is composed of irradiation device, gamma-ray spectrometer and data analyzing instruments. The element concentration is calculated by using KAYZERO/SOLCOI software with the K 0 standardization method. In this paper, we review on a construction of this INAA support system in JRR-3M of JAERI. (author)

  7. Neutron activation analysis of Etruscan pottery

    International Nuclear Information System (INIS)

    Whitehead, J.; Silverman, A.; Ouellet, C.G.; Clark, D.D.; Hossain, T.Z.

    1992-01-01

    Neutron activation analysis (NAA) has been widely used in archaeology for compositional analysis of pottery samples taken from sites of archaeological importance. Elemental profiles can determine the place of manufacture. At Cornell, samples from an Etruscan site near Siena, Italy, are being studied. The goal of this study is to compile a trace element concentration profile for a large number of samples. These profiles will be matched with an existing data bank in an attempt to understand the place of origin for these samples. The 500 kW TRIGA reactor at the Ward Laboratory is used to collect NAA data for these samples. Experiments were done to set a procedure for the neutron activation analysis with respect to sample preparation, selection of irradiation container, definition of activation and counting parameters and data reduction. Currently, we are able to analyze some 27 elements in samples of mass 500 mg with a single irradiation of 4 hours and two sequences of counting. Our sensitivity for many of the trace elements is better than 1 ppm by weight under the conditions chosen. In this talk, details of our procedure, including quality assurance as measured by NIST standard reference materials, will be discussed. In addition, preliminary results from data treatment using cluster analysis will be presented. (author)

  8. ACTIV87 Fast neutron activation cross section file 1987

    International Nuclear Information System (INIS)

    Manokhin, V.N.; Pashchenko, A.B.; Plyaskin, V.I.; Bychkov, V.M.; Pronyaev, V.G.; Schwerer, O.

    1989-10-01

    This document summarizes the content of the Fast Neutron Activation Cross Section File based on data from different evaluated data libraries and individual evaluations in ENDF/B-5 format. The entire file or selective retrievals from it are available on magnetic tape, free of charge, from the IAEA Nuclear Data Section. (author)

  9. Calibration of neutron yield activation measurements at JET using MCNP and furnace neutron transport codes

    International Nuclear Information System (INIS)

    Pillon, M.; Martone, M.; Verschuur, K.A.; Jarvis, O.N.; Kaellne, J.

    1989-01-01

    Neutron transport calculations have been performed using fluence ray tracing (FURNACE code) and Monte Carlo particle trajectory sampling methods (MCNP code) in order to determine the neutron fluence and energy distributions at different locations in the JET tokamak. These calculations were used to calibrate the activation measurements used in the determination of the absolute fusion neutron yields from the JET plasma. We present here the neutron activation response coefficients calculated for three different materials. Comparison of the MCNP and FURNACE results helps identify the sources of error in these neutron transport calculations. The accuracy of these calculations was tested by comparing the total 2.5 MeV neutron yields derived from the activation measurements with those obtained with calibrated fission chambers; agreement at the ±15% level was demonstrate. (orig.)

  10. Accounting for the thermal neutron flux depression in voluminous samples for instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Overwater, R.M.W.; Hoogenboom, J.E.

    1994-01-01

    At the Delft University of Technology Interfaculty Reactor Institute, a facility has been installed to irradiate cylindrical samples with diameters up to 15 cm and weights up to 50 kg for instrumental neutron activation analysis (INAA) purposes. To be able to do quantitative INAA on voluminous samples, it is necessary to correct for gamma-ray absorption, gamma-ray scattering, neutron absorption, and neutron scattering in the sample. The neutron absorption and the neutron scattering are discussed. An analytical solution is obtained for the diffusion equation in the geometry of the irradiation facility. For samples with known composition, the neutron flux--as a function of position in the sample--can be calculated directly. Those of unknown composition require additional flux measurements on which least-squares fitting must be done to obtain both the thermal neutron diffusion coefficient D s and the diffusion length L s of the sample. Experiments are performed to test the theory

  11. Pulsed neutron generator for mass flow measurement using the pulsed neutron activation technique

    International Nuclear Information System (INIS)

    Rochau, G.E.; Hornsby, D.R.; Mareda, J.F.; Riggan, W.C.

    1980-01-01

    A high-output, transportable neutron generator has been developed to measure mass flow velocities in reactor safety tests using the Pulsed Neutron Activation (PNA) Technique. The PNA generator produces >10 10 14 MeV D-T neutrons in a 1.2 millisecond pulse. The Millisecond Pulse (MSP) Neutron Tube, developed for this application, has an expected operational life of 1000 pulses, and it limits the generator pulse repetition rate to 12 pulses/minute. A semiconductor neutron detector is included in the generator package to monitor the neutron output. The control unit, which can be operated manually or remotely, also contains a digital display with a BCD output for the neutron monitor information. The digital logic of the unit controls the safety interlocks and rejects transient signals which could accidently fire the generator

  12. Neutron activation system for spectral measurements of pulsed ion diode neutron production

    International Nuclear Information System (INIS)

    Hanson, D.L.; Kruse, L.W.

    1980-02-01

    A neutron energy spectrometer has been developed to study intense ion beam-target interactions in the harsh radiation environment of a relativistic electron beam source. The main component is a neutron threshold activation system employing two multiplexed high efficiency Ge(Li) detectors, an annihilation gamma coincidence system, and a pneumatic sample transport. Additional constraints on the neutron spectrum are provided by total neutron yield and time-of-flight measurements. A practical lower limit on the total neutron yield into 4π required for a spectral measurement with this system is approx. 10 10 n where the neutron yield is predominantly below 4 MeV and approx. 10 8 n when a significant fraction of the yield is above 4 MeV. Applications of this system to pulsed ion diode neutron production experiments on Hermes II are described

  13. Neutron detection using Dy2O3 activation detectors

    International Nuclear Information System (INIS)

    Gomaa, M.A.; Mohamed, E.J.

    1979-01-01

    The aim of the present study is to examine the usefulness of Dy 2 O 3 not only as thermal neutron activation detector but also as a fast neutron detector. For thermal neutrons, the half life of 165 Dy is measured to be (141 +- 6) min, its response to thermal neutrons is (2.18 +- 0.01) cpm/ncm -2 s -1 for a 250 mg Dy 2 O 3 pellet. For fast neutrons the Dy 2 O 3 detector is placed within a 20 cm polyethylene sphere and its response is found to be (2.2 +- 0.1) cpm/ncm -2 s -1 for 4 MeV neutrons and (2.10 +- 0.04) cpm/ncm -2 s -1 for 14 MeV neutrons. For neutron dosimetry, its response is found to be (16.7 +- 0.4) cpm per mrem h -1 . (author)

  14. Neutron scattering from α-Ce at epithermal neutron energies

    Indian Academy of Sciences (India)

    phose into delocalised conduction electrons, while maintaining their f character.” “This insight that f electrons could form energy bands and contribute to the. Fermi surface was controversial for many ..... [11] A P Murani, Z A Bowden, A D Taylor, R Osborn and W G Marshall, Phys. Rev. B48, 13981 (1993). [12] Y Kuramoto ...

  15. Future neutron data activity on the neutron source IREN

    International Nuclear Information System (INIS)

    Janeva, N.B.; Koyumdjieva, N.T.; Grigoriev, Y.V.; Gundorin, N.A.; Mareev, Y.D.; Kopatch, Y.N.; Pikelner, L.B.; Shvetsov, V.N.; Sedyshev, P.V.; Zeinalov, S.; Ruskov, I.N.

    2011-01-01

    The global energy demand continues to rise and nuclear power has a potential to be part of the solution of energy problem. Complete and accurate information about the nuclear reactions ensures developing and operating nuclear reactors to reach high efficiencies and adequate safety standards. This demands many nuclear data of improved quality, including covariance nuclear data and correlations. The new neutron source IREN (1 stage) has been put in operation at the end of 2009. The first stage includes the construction of the LUE-200 linear accelerator and non multiplying target. The first measured TOF spectra have been presented recently. The facility is in continuous completion and improvement (according to the full version in the project). The program for neutron data investigation on the IREN neutron source is in preparation. The measuring targets for neutron cross-sections TOF spectra would be selected between isotopes of construction materials, fission products and minor actinides. Now the experimental facilities are in preparation - detectors, innovative electronics equipment and systems for data acquisition and analysis. (authors)

  16. NAC, Neutron Activation Analysis and Isotope Inventory

    International Nuclear Information System (INIS)

    1995-01-01

    1 - Description of program or function: NAC was designed to predict the neutron-induced gamma-ray radioactivity for a wide variety of composite materials. The NAC output includes the input data, a list of all reactions for each constituent element, and the end-of-irradiation disintegration rates for each reaction. NAC also compiles a product isotope inventory containing the isotope name, the disintegration rate, the gamma-ray source strength and the absorbed dose rate at 1 meter from an unshielded point source. The induced activity is calculated as a function of irradiation and decay times; the effect of cyclic irradiation can also be calculated. 2 - Method of solution: The standard neutron activation and decay equations are programmed. A data library is supplied which contains target element names, atomic densities, reaction indices, individual reactions and reaction parameters, and product isotopes and gamma energy yields. 3 - Restrictions on the complexity of the problem: Each composite material may consist of up to 20 different elements and up to 20 different decay times may be included. Both limits may be increased by the user by increasing the appropriate items in the dimension statement

  17. Neutron activation analysis: recent developments and applications

    International Nuclear Information System (INIS)

    Acharya, R.; Reddy, A.V.R.

    2012-01-01

    Neutron activation analysis (NAA) is a powerful isotope specific nuclear analytical technique for simultaneous determination of major to trace elemental concentrations in diverse matrices. NAA is associated with high analytical sensitivities and low detection limits (ppm to ppb) due to utilization of high neutron flux from research reactors and high efficiency high resolution gamma ray spectrometry. Elemental concentrations are determined either by conventional NAA using relative method or by single comparator method of NAA (k 0 -NAA). Since 1994, Radiochemistry Division is actively engaged in developments and applications of k 0 -based NAA and Prompt Gamma ray NAA (PGNAA) methods for compositional characterization of materials, in addition to conventional instrumental NAA (INAA) and chemical NAA (CNAA) methods for total as well as speciation studies. The article briefly summarizes developments of k 0 based method of NAA using an external single comparator (k 0 -NAA) and an internal monostandard (lM-NAA) and PGNAA and their applications to small as well as large size samples. The article also briefly highlights the application of INAA and chemical NAA (CNAA) for speciation studies of arsenic and iodine in environmental and food samples respectively and bioaccesibility of selenium in food samples and trace elements wheatgrass samples

  18. Selected industrial and environmental applications of neutron activation analysis

    International Nuclear Information System (INIS)

    Kucera, J.

    1999-01-01

    A review of the applications of Instrumental Neutron Activation Analysis (INAA) in the industrial and environmental fields is given. Detection limits for different applications are also given. (author)

  19. Neutron and gamma-ray spectra of 239PuBe and 241AmBe

    International Nuclear Information System (INIS)

    Vega-Carrillo, H.R.; Manzanares-Acuna, Eduardo; Becerra-Ferreiro, A.M.; Carrillo-Nunez, Aureliano

    2002-01-01

    Neutron and gamma-ray spectra of 239 PuBe and 241 AmBe were measured and their dosimetric features were calculated. Neutron spectra were measured using a multisphere neutron spectrometer with a 6 LiI(Eu) scintillator. The 239 PuBe neutron spectrum was measured in an open environment, while the 241 AmBe neutron spectrum was measured in a closed environment. Gamma-ray spectra were measured using a NaI(Tl) scintillator using the same experimental conditions for both sources. The effect of measuring conditions for the 241 AmBe neutron spectrum indicates the presence of epithermal and thermal neutrons. The low-resolution neutron spectra obtained with the multisphere spectrometer allows one to calculate the dosimetric features of neutron sources. At 100 cm both sources produce approximately the same count rate as that of the 4.4 MeV gamma-ray per unit of alpha emitter activity

  20. Development of high flux thermal neutron generator for neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vainionpaa, Jaakko H., E-mail: hannes@adelphitech.com [Adelphi Technology, 2003 E Bayshore Rd, Redwood City, CA 94063 (United States); Chen, Allan X.; Piestrup, Melvin A.; Gary, Charles K. [Adelphi Technology, 2003 E Bayshore Rd, Redwood City, CA 94063 (United States); Jones, Glenn [G& J Jones Enterprice, 7486 Brighton Ct, Dublin, CA 94568 (United States); Pantell, Richard H. [Department of Electrical Engineering, Stanford University, Stanford, CA (United States)

    2015-05-01

    The new model DD110MB neutron generator from Adelphi Technology produces thermal (<0.5 eV) neutron flux that is normally achieved in a nuclear reactor or larger accelerator based systems. Thermal neutron fluxes of 3–5 · 10{sup 7} n/cm{sup 2}/s are measured. This flux is achieved using four ion beams arranged concentrically around a target chamber containing a compact moderator with a central sample cylinder. Fast neutron yield of ∼2 · 10{sup 10} n/s is created at the titanium surface of the target chamber. The thickness and material of the moderator is selected to maximize the thermal neutron flux at the center. The 2.5 MeV neutrons are quickly thermalized to energies below 0.5 eV and concentrated at the sample cylinder. The maximum flux of thermal neutrons at the target is achieved when approximately half of the neutrons at the sample area are thermalized. In this paper we present simulation results used to characterize performance of the neutron generator. The neutron flux can be used for neutron activation analysis (NAA) prompt gamma neutron activation analysis (PGNAA) for determining the concentrations of elements in many materials. Another envisioned use of the generator is production of radioactive isotopes. DD110MB is small enough for modest-sized laboratories and universities. Compared to nuclear reactors the DD110MB produces comparable thermal flux but provides reduced administrative and safety requirements and it can be run in pulsed mode, which is beneficial in many neutron activation techniques.

  1. Utilization of the intense pulsed neutron source (IPNS) at Argonne National Laboratory for neutron activation analysis

    International Nuclear Information System (INIS)

    Heinrich, R.R.; Greenwood, L.R.; Popek, R.J.; Schulke, A.W. Jr.

    1983-01-01

    The Intense Pulsed Neutron Source (IPNS) neutron scattering facility (NSF) has been investigated for its applicability to neutron activation analysis. A polyethylene insert has been added to the vertical hole VT3 which enhances the thermal neutron flux by a factor of two. The neutron spectral distribution at this position has been measured by the multiple-foil technique which utilized 28 activation reactions and the STAYSL computer code. The validity of this spectral measurement was tested by two irradiations of National Bureau of Standards SRM-1571 (orchard leaves), SRM-1575 (pine needles), and SRM-1645 (river sediment). The average thermal neutron flux for these irradiations normalized to 10 μamp proton beam is 4.0 x 10 11 n/cm 2 -s. Concentrations of nine trace elements in each of these SRMs have been determined by gamma-ray spectrometry. Agreement of measured values to certified values is demonstrated to be within experiment error

  2. Neutron activation analysis: Modelling studies to improve the neutron flux of Americium-Beryllium source

    Energy Technology Data Exchange (ETDEWEB)

    Didi, Abdessamad; Dadouch, Ahmed; Tajmouati, Jaouad; Bekkouri, Hassane [Advanced Technology and Integration System, Dept. of Physics, Faculty of Science Dhar Mehraz, University Sidi Mohamed Ben Abdellah, Fez (Morocco); Jai, Otman [Laboratory of Radiation and Nuclear Systems, Dept. of Physics, Faculty of Sciences, Tetouan (Morocco)

    2017-06-15

    Americium–beryllium (Am-Be; n, γ) is a neutron emitting source used in various research fields such as chemistry, physics, geology, archaeology, medicine, and environmental monitoring, as well as in the forensic sciences. It is a mobile source of neutron activity (20 Ci), yielding a small thermal neutron flux that is water moderated. The aim of this study is to develop a model to increase the neutron thermal flux of a source such as Am-Be. This study achieved multiple advantageous results: primarily, it will help us perform neutron activation analysis. Next, it will give us the opportunity to produce radio-elements with short half-lives. Am-Be single and multisource (5 sources) experiments were performed within an irradiation facility with a paraffin moderator. The resulting models mainly increase the thermal neutron flux compared to the traditional method with water moderator.

  3. Neutron activation analysis of airborne inorganic pollutants

    International Nuclear Information System (INIS)

    Oerdoegh, M.; Kalman, L.

    1975-01-01

    The aim of the studies was to determine the radioactive and non-radioactive pollution of the air in the environment of the atomic reactor WWR-S of the Hungarian Academy of Sciences. Accordingly the investigations were carried out by two ways: the samples were analysed partly without previous irradiation and partly by neutron activation analysis. The use of several filter papers was studied and the most suitable filter paper (Whatman No. 41) was chosen for this investigation. The quantitative determination of more than twenty elements has been performed. First the natural activity of the aerosol samples taken periodically was measured and subsequently they have been analysed after irradiation in the atomic reactor for 1 minute, 1 hour, and 50 hours, respectively. A 45 cm 3 Ge/Li detector/ Nuclear Diodes/ was used in connection with a 1024 channel analyzer /type NTA-512B/. The analyses were made nondestructively, and the gamma-spectra were evaluated by computer. (K.A.)

  4. Synthetic multi-element standards: a good tool for calibration and quality control of irradiation facilities used for neutron activation analysis

    International Nuclear Information System (INIS)

    Vermaercke, P.

    2007-01-01

    Neutron activation analysis (NAA) is a physical technique used for the absolute measurement of the concentration of substances in solids and liquids. The method uses neutron irradiation which is commonly realised using a nuclear reactor in order to activate (make radioactive) different isotopes of the elements present in the sample. The radionuclides produced in this way emit gamma-rays that are characteristic of the elements present in the sample. Using gamma-ray spectrometry these radionuclides can then be identified and quantified, and hence their concentration in the sample can be determined. Although NAA is a straightforward method it requires a sound control of the many physical parameters involved to obtain accurate results and to guarantee a set accuracy in routine analysis. The accuracy of NAA depends on the specific measurement method used. One can perform NAA in a relative way by co-irradiating a known standard and the unknown sample in the same conditions and by comparing the ratio of gamma-rays they emit. Relative NAA has limited applicability since it requires reference standards with a comparable composition as the unknown. A more generally applicable method is the k0-NAA method. In the k0-NAA method all measurements are relative to the element Au resulting in 198Au when irradiated. The k0-NAA method further relies on the fact that the neutron energy spectrum produced in a given position in the reactor can be parameterised with two parameters: the shape factor of the epithermal neutron flux, indicating the deviation of the epithermal neutron spectrum from the ideal 1/E shape approximated by a 1/E1+a distribution, with E the neutron energy; f: the thermal-to-epithermal neutron flux ratio. The parameters f and a are characteristic for the irradiation facility (reactor and irradiation channels) and may change or fluctuate in time according to the irradiation conditions. The way elements activate (become radioactive) when interacting with neutrons is

  5. Improved Fission Neutron Data Base for Active Interrogation of Actinides

    Energy Technology Data Exchange (ETDEWEB)

    Pozzi, Sara; Czirr, J. Bart; Haight, Robert; Kovash, Michael; Tsvetkov, Pavel

    2013-11-06

    This project will develop an innovative neutron detection system for active interrogation measurements. Many active interrogation methods to detect fissionable material are based on the detection of neutrons from fission induced by fast neutrons or high-energy gamma rays. The energy spectrum of the fission neutrons provides data to identify the fissionable isotopes and materials such as shielding between the fissionable material and the detector. The proposed path for the project is as follows. First, the team will develop new neutron detection systems and algorithms by Monte Carlo simulations and bench-top experiments. Next, They will characterize and calibrate detection systems both with monoenergetic and white neutron sources. Finally, high-fidelity measurements of neutron emission from fissions induced by fast neutrons will be performed. Several existing fission chambers containing U-235, Pu-239, U-238, or Th-232 will be used to measure the neutron-induced fission neutron emission spectra. The challenge for making confident measurements is the detection of neutrons in the energy ranges of 0.01 – 1 MeV and above 8 MeV, regions where the basic data on the neutron energy spectrum emitted from fission is least well known. In addition, improvements in the specificity of neutron detectors are required throughout the complete energy range: they must be able to clearly distinguish neutrons from other radiations, in particular gamma rays and cosmic rays. The team believes that all of these challenges can be addressed successfully with emerging technologies under development by this collaboration. In particular, the collaboration will address the area of fission neutron emission spectra for isotopes of interest in the advanced fuel cycle initiative (AFCI).

  6. Evaluation of heavy metal uptake in micropterus salmoides (Largemouth Bass) of Lake Austin, TX by neutron activation analysis

    International Nuclear Information System (INIS)

    Weaver, J.; Wilson, W.H.; Biegalski, S.R.F.; O'Kelly, D.J.

    2009-01-01

    Neutron activation analysis was used to investigate and quantify the level of heavy metal uptake in the marine environment of Lake Austin in Austin, TX. Specifically, the samples studied were largemouth bass, or micropterus salmoides. The presence of heavy metals in the food chain presents multiple hazards, mostly as a food hazard for those species that ingest the fish, namely humans. To measure the concentrations of heavy metals in various fish samples, the nuclear analytical technique of neutron activation analysis (NAA) was used. Both epithermal and thermal irradiations were conducted for the NAA to look for short and long-lived radioisotopes, respectively. The samples themselves consisted of liver and tissue samples for each of the fish caught. Each sample was freeze-dried and homogenized before irradiation and spectrum acquisition. The results showed that all levels of heavy metals were not sufficient enough to make the fish unsafe for eating, with the highest levels being found for iron and zinc. Gold was found to be at much higher concentrations in the younger fish and virtually non-existent in the larger of the samples. (author)

  7. Investigation of ancient pottery from Lefkanti, Greece, by epithermal gamma spectroscopy using loss-free counting technology

    International Nuclear Information System (INIS)

    Ochsenkuehn, K.M.; Zouridakis, N.

    1996-01-01

    For the analysis of pottery fragments from ancient Lefkanti, instrumental neutron activation analysis was used. To have a good throughput of samples, a detectable series of short-lived isotopes was selected for the investigation. The problem of the initial high radioactivity, which normally hinders a fast γ-spectroscopic analysis, was eluded by using loss-free counting technology. This technology allows the measurement of pottery samples of about 100 mg size 1 day after a 30 min epithermal irradiation. Up to 15 samples could be analyzed in one day under these working conditions, having the possibility to analyze the elements As, Eu, Ga, Gd, La, Mn, Sb, Sm, Th, U, W and Zn, which are enough to perform statistical characterizations of potteries. (author). 11 refs., 2 figs., 1 tab

  8. Industrial applications of neutron activation analysis

    International Nuclear Information System (INIS)

    Hossain, T.Z.

    2001-01-01

    Neutron activation analysis has been widely used in the industry and over the years played a key role in the development of manufacturing process as well as monitoring of the process flow. In this context NAA has been utilized both in R and D, and in the factory as a flexible analytical tool. It has been used successfully in numerous industries including broad categories such as Chemical, Pharmaceutical, Mining, Photographic, Oil and Gas, Automobile, Defense, Semiconductor and Electronic industries. Dow Chemical owns and operates a research reactor for analytical measurements of samples generated in both R and D, and manufacturing area in its plant in Midland, Michigan. Although most industries do not have reactors on their campus but use an off site reactor regularly, and often have in-house neutron sources such as a 252 Cf used primarily for NAA. In most industrial materials analysis laboratory NAA is part of a number of analytical techniques such as ICP-MS, AA, SIMS, FTIR, XRF, TXRF etc. Analysis of complex industrial samples may require data from each of these methods to provide a clear picture of the materials issues involved. With the improvement of classical analytical techniques, and the introduction of new techniques, e.g. TXRF, the role of NAA continues to be a key bench mark technique that provides accurate and reliable data. The strength of the NAA in bulk analysis is balanced by its weakness in providing surface sensitive or spatially resolved analysis as is required by many applications. (author)

  9. Neutron dosimetry in boron neutron capture therapy

    International Nuclear Information System (INIS)

    Fairchild, R.G.; Miola, U.J.; Ettinger, K.V.

    1981-01-01

    The recent development of various borated compounds and the utilization of one of these (Na 2 B 12 H 11 SH) to treat brain tumors in clinical studies in Japan has renewed interest in neutron capture therapy. In these procedures thermal neutrons interact with 10 B in boron containing cells through the 10 B(n,α) 7 Li reaction producing charged particles with a maximum range of approx. 10μm in tissue. Borated analogs of chlorpromazine, porphyrin, thiouracil and deoxyuridine promise improved tumor uptake and blood clearance. The therapy beam from the Medical Research Reactor in Brookhaven contains neutrons from a modified and filtered fission spectrum and dosimetric consequences of the use of the above mentioned compounds in conjunction with thermal and epithermal fluxes are discussed in the paper. One of the important problems of radiation dosimetry in capture therapy is determination of the flux profile and, hence, the dose profile in the brain. This has been achieved by constructing a brain phantom made of TE plastic. The lyoluminescence technique provides a convenient way of monitoring the neutron flux distributions; the detectors for this purpose utilize 6 Li and 10 B compounds. Such compounds have been synthesized specially for the purpose of dosimetry of thermal and epithermal beams. In addition, standard lyoluminescent phosphors, like glutamine, could be used to determine the collisional component of the dose as well as the contribution of the 14 N(n,p) 14 C reaction. Measurements of thermal flux were compared with calculations and with measurements done with activation foils

  10. Personal neutron dosimeter using solid-state track detector

    International Nuclear Information System (INIS)

    Mettripan, S.

    1980-01-01

    A cellulose nitrate film coated on both sides with lithium tetraborate was used as a neutron dosimeter for surveillance of personnel exposed to thermal and epithermal neutron. It was found that the optimum etching conditions used were 10% solution of sodium hydroxide, 60 degrees C and 20 minutes etching time and the alpha track densities from the (n,α) reaction on the films were proportional to thermal and epithermal neutron fluxes. The response of the film was found to be 1.068 x 10 -3 tracks per thermal neutron and 3.438 x 10 -4 tracks per epithermal neutron

  11. Neutron flux of 100kW in the irradiation terminals of the IPR-R1 Triga Reactor

    International Nuclear Information System (INIS)

    Zangirolami, Dante Marco

    2009-01-01

    In this work, it was carried out a study of the neutron flux in the IPR-R1 TRIGA reactor irradiation facilities: rotary specimen rack (RSR), pneumatic transfer tube two (PTT2) and the central thimble (CT). The objective was to obtain the neutron flux profile on the RSR, which has forty irradiation positions, and also values for the thermal and epithermal neutron fluxes of some RSR positions and also of the PTT2 and of the CT facility. It was applied the neutron activation analysis of a reference material, Al-Au (0.1%) alloy. Irradiations were performed on 16 different dates. It was concluded that for the RSR, the average value of thermal and epithermal neutron fluxes depends on the vertical position of the reactor control rods. Neutron flux variations along the RSR form a characteristic profile, whose values depend on the location of the irradiation position in the reactor core and on the control rods vertical position. In the RSR, the obtained values of thermal and epithermal neutron flux were (8.1 +- 0.3) x 10 11 n.cm -2 .s -1 , and (3.4 +- 0.2)x10 10 n.cm -2 .s -1 , respectively. For the PTT2 and the CT, the values for the epithermal neutron flux were respectively (3.3 +- 0.2) x 10 9 n.cm -2 .s -1 and (2.6 +- 0.1) x 10 11 n.cm -2 .s -1 . For these facilities, the thermal neutron flux was estimated, and the obtained values were (2.4 +- 0.2) x 10 11 n.cm -2 .s -1 and (2.8 +- 0.1)x10 12 n.cm -2 .s -1 for the PTT2 and the CT, respectively. (author)

  12. On the research activities in reactor and neutron physics using the first egyptian research reactor

    International Nuclear Information System (INIS)

    Hassan, A.M.

    2000-01-01

    A review on the most important research activities in reactor and neutron physics using the first Egyptian Research Reactor (ET-RR-1) is given. An out look on: neutron cross-sections, neutron flux, neutron capture gamma-ray spectroscopy, neutron activation analysis, neutron diffraction and radiation shielding experiments, is presented

  13. Neutron capture prompt gamma-ray activation analysis at the NIST cold neutron research facility

    Energy Technology Data Exchange (ETDEWEB)

    Lindstrom, R M; Zeisler, R; Vincent, D H; Greenberg, R R; Stone, C A; Mackey, E A [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Anderson, D L [Food and Drug Administration, Washington, DC (United States); Clark, D D [Cornell Univ., Ithaca, NY (United States)

    1993-01-01

    An instrument for neutron capture prompt gamma-ray activation analysis (PGAA) has been constructed as part of the Cold Neutron Research Facility at the 20 MW National Institute of Standards and Technology Research Reactor. The neutron fluence rate (thermal equivalent) is 1.5*10[sup 8] n*cm[sup -2]*s[sup -] [sup 1], with negligible fast neutrons and gamma-rays. With compact geometry and hydrogen-free construction, the sensitivity is sevenfold better than an existing thermal instrument. Hydrogen background is thirtyfold lower. (author) 17 refs.; 2 figs.

  14. Halogen determination in Arctic aerosols by neutron activation analysis with Compton suppression methods

    International Nuclear Information System (INIS)

    Landsberger, S.; Basunia, M.S.; Iskander, F.

    2001-01-01

    The study of halogens particularly bromine and chlorine in Arctic aerosols has received a great deal of attention in the past decade in ozone depletion during polar sunrise studies. Iodine has also been studied as part of geochemical cycling. It was shown that all three of the above elements can be determined simultaneously with very low detection limits using epithermal NAA in conjunction with Compton suppression methods. Besides lowering the background considerably, Compton suppression can eliminate or minimize the overlapping peak of the 620 keV photopeak arising form the 1642 keV double escape peak of 38 Cl interfering with the 616.9 keV photopeak of 79 Br(n,γ) 80 Br reaction. Iodine is ideally determined by epithermal NAA because of its very good resonance integral cross-section. Although chlorine is usually determined using thermal neutrons via the 37 Cl(n,γ) 38 Cl reactions, epithermal NAA is still feasible for the Arctic aerosol, since it has a major sea-salt component. (author)

  15. Measurements of fusion neutron yields by neutron activation technique: Uncertainty due to the uncertainty on activation cross-sections

    Energy Technology Data Exchange (ETDEWEB)

    Stankunas, Gediminas, E-mail: gediminas.stankunas@lei.lt [Lithuanian Energy Institute, Laboratory of Nuclear Installation Safety, Breslaujos str. 3, LT-44403 Kaunas (Lithuania); EUROfusion Consortium, JET, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Batistoni, Paola [ENEA, Via E. Fermi, 45, 00044 Frascati, Rome (Italy); EUROfusion Consortium, JET, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Sjöstrand, Henrik; Conroy, Sean [Department of Physics and Astronomy, Uppsala University, PO Box 516, SE-75120 Uppsala (Sweden); EUROfusion Consortium, JET, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

    2015-07-11

    The neutron activation technique is routinely used in fusion experiments to measure the neutron yields. This paper investigates the uncertainty on these measurements as due to the uncertainties on dosimetry and activation reactions. For this purpose, activation cross-sections were taken from the International Reactor Dosimetry and Fusion File (IRDFF-v1.05) in 640 groups ENDF-6 format for several reactions of interest for both 2.5 and 14 MeV neutrons. Activation coefficients (reaction rates) have been calculated using the neutron flux spectra at JET vacuum vessel, both for DD and DT plasmas, calculated by MCNP in the required 640-energy group format. The related uncertainties for the JET neutron spectra are evaluated as well using the covariance data available in the library. These uncertainties are in general small, but not negligible when high accuracy is required in the determination of the fusion neutron yields.

  16. Neutron activation in EBT-P

    International Nuclear Information System (INIS)

    Driemeyer, D.E.

    1983-01-01

    Neutron activation due to photoneutron production in the lead shields proposed to protect the EBT-P superconducting coils from excessive x-ray heating was investigated. The photoneutron flux distribution in various EBT-P structural components was calculated for typical upgrade operating conditions using a standard two-dimensional transport model (TWOTRAN). Activity levels were then evaluated for major structural materials using activation cross sections tabulated in the GAMMON library. Activation dose rates in the device enclosure following several days of 8h/day upgrade (90GHz) operation were found to be approx. 6 mrem/h, decaying to <0.25 mrem/h in approx. 3 days. This requires radiation monitoring of all personnel entering the device enclosure during this time, but should not generally restrict hands on access to the device. There is thus no strong motivation to replace lead with another shield material; however, it may be desirable to borate the enclosure walls in order to reduce the effect which impurities might have on activity levels

  17. Final design and construction issues of the TAPIRO epithermal column

    International Nuclear Information System (INIS)

    Burn, K.W.; Casalini, L.; Nava, E.; Tinti, R.; Martini, S.; Mondini, D.; Rosi, G.

    2006-01-01

    The construction of the epithermal column for clinical trials at the 5 kW fast reactor TAPIRO (ENEA, Casaccia, Italy) has been completed, the experimental bunker in the reactor hall has been designed and the beam characterisation will shortly be underway. As has been reviewed at the last two ICNCT conferences, the low power of the neuron source and the relatively distant patient position outside the reactor shield led to a column design with certain characteristics. One consequence is the employment of a collimator containing lead of high purity with the resultant problems of mechanical construction. Another is the substantial neutron leakage from the column outside the aperture into the experimental bunker. Furthermore the absence of a gamma shield has led to an electron dose to the skin. This is resolved with an electron shield of aluminium. Here the construction and final design issues are discussed and the state of the project is presented. (author)

  18. Coal ash parameters by neutron activation

    International Nuclear Information System (INIS)

    Chrusciel, Edward; Chau, N.D.; Niewodniczanski, J.W.

    1994-01-01

    The coal parameters, ash content and ash slagging index, may be strongly related to the chemical composition of mineral impurities in coal. Based on this assumption the authors have examined the feasibility of neutron activation techniques, both as a laboratory and a well logging method, by recording induced γ-rays in the two energy intervals with the help of a scintillation γ-ray spectrometer. Results from the Upper Silesiab Coal Basin have shown that the method can be used to evaluate the ash content and ash fusion temperature, both in the laboratory and in well logging; the corresponding mean standard deviations being 1.5 wt% and 35 o C; and 3 wt% and 45 o C respectively. (author)

  19. Activity report on neutron scattering research

    International Nuclear Information System (INIS)

    Nagao, M.; Tawata, N.; Fujii, Y.

    1998-01-01

    The experiments performed on the thirteen university-owned spectrometers installed at JRR-3M of JAERI in the fiscal year of 1997 were described in this report. The latest ''Neutron News'' (vol. 9, issue 3, 1998) has featured highlights of the activities based on the JRR-3M and its cover displays a graph showing an endless increase of the number of proposals to the users program in the fiscal 1997. The university-owned spectrometers are available for general users all over Japan. The users' requirement for a higher flux beam reactor became larger and larger with time. Thus, JAERI has refurbished JRR-3 to satisfy these demands. In 1997, a joint project between Chiba University and Institute for Solid State Physics (ISSP) started to build a new 4-cycle diffractometer for crystal physics/chemistry at T 2-2 beam port on a thermal guide. (M.N.)

  20. Instrumental neutron activation analysis of kidney stones

    International Nuclear Information System (INIS)

    Sarmani, S.; Kuan, L.L.; Bakar, M.A.A.

    1990-01-01

    Kidney stone samples of the types calcium oxalate, uric acid, and xanthine were analyzed for their elemental contents by neutron activation analysis to study both the elemental correlation and influence of element on stone precipitation processes. Elements, such as Al, Au, Br, Ca, Cl, Co, Cr, Fe,H, I, K, Mg, Na, Sb, Se, Sr, and Zn, were determined quantitatively. Calcium oxalate stones contained higher concentration of all the elements analyzed compared to uric acid or xanthine stones. The concentrations of Cl, Fe, K, Na, Sr, and Zn were relatively higher than Au, Co, Cr, and Sb. A positive correlation exists between Ca and Zn, whereas a negative correlation exists between Sr and Ca. Zinc may play an important role in the formation of calcium oxalate stone

  1. Neutron activation analysis of urinary calculi

    International Nuclear Information System (INIS)

    Souka, N.; Souka, S.; Sanad, W.; Abdel-Rassoul, A.A.

    1974-01-01

    Urinary calculi resulting from disorders in the urinary system are mostly composed of uric acid, urates, calcium oxalate, alkaline earth phosphates (Ca and Mg), triple phosphate (magnesium ammonium phosphate), calcium carbonate, cystine, xanthine, and traces of proteins. The determination of these macro-constituents has been carried out by different analytical procedures. No attempts however, have been reported regarding the determination of trace elements in urinary stones, apart from that of Herring et al., who investigated the consumption of strontium by urolithiasis patients. The present work is a non-destructive neutron activation analysis of urinary calculi, to search the variation in concentration of certain trace elements with the chemical composition of the calculus

  2. Instrumental neutron activation analysis of soil sample

    International Nuclear Information System (INIS)

    Abdul Khalik Haji Wood.

    1983-01-01

    This paper describes the analysis of soil samples collected from 5 different location around Sungai Lui, Kajang, Selangor, Malaysia. These sample were taken at 22-24 cm from the top of the ground and were analysed using the techniques of Instrumental Neutron Activation Analysis (INAA). The analysis on soil sample taken above 22-24 cm level were done in order to determine if there is any variation in elemental contents at different sampling levels. The results indicate a wide variation in the contents of the samples. About 30 elements have been analysed. The major ones are Na, I, Cl, Mg, Al, K, Ti, Ca and Fe. Trace elements analysed were Ba, Sc, V, Cr, Mn, Ga, As, Zn, Br, Rb, Co, Hf, Zr, Th, U, Sb, Cs, Ce, Sm, Eu, Tb, Dy, Yb, Lu and La. (author)

  3. Development of the Method of Bacterial Leaching of Metals out of Low-Grade Ores, Rocks, and Industrial Wastes Using Neutron Activation Analysis

    CERN Document Server

    Tsertsvadze, L A; Petriashvili, Sh G; Chutkerashvili, D G; Kirkesali, E I; Frontasyeva, M V; Pavlov, S S; Gundorina, S F

    2001-01-01

    The results of preliminary investigations aimed at the development of an economical and easy to apply technique of bacterial leaching of rare and valuable metals out of low-grade ores, complex composition ores, rocks, and industrial wastes in Georgia are discussed. The main groups of microbiological community of the peat suspension used in the experiments of bacterial leaching are investigated and the activity of particular microorganisms in the leaching of probes with different mineral compositions is assessed. The element composition of the primary and processed samples was investigated by the epithermal neutron activation analysis method and the enrichment/subtraction level is estimated for various elements. The efficiency of the developed technique to purify wastes, extract some scrace metals, and enrich ores or rocks in some elements, e.g. Au, U, Th, Cs, Sr, Rb, Sc, Zr, Hf, Ta, Gd, Er, Lu, Ce, etc., is demonstrated.

  4. Development of educational program for neutron activation analysis

    International Nuclear Information System (INIS)

    Chung, Yong Sam; Moon, Jong Hwa; Kim, Sun Ha; Ryel, Sung; Kang, Young Hwan; Lee, Kil Yong; Yeon, Yeon Yel; Cho, Seung Yeon

    2000-08-01

    This technical report is developed to apply an educational and training program for graduate student and analyst utilizing neutron activation analysis. The contents of guide book consists of five parts as follows; introduction, gamma-ray spectrometry and measurement statistics, its applications, to understand of comprehensive methodology and to utilize a relevant knowledge and information on neutron activation analysis

  5. Fast neutron activation analysis of Kalewa (Myanmar) coal

    Energy Technology Data Exchange (ETDEWEB)

    Myint, U; Naing, W [Yangon Univ. (Myanmar). Dept. of Chemistry

    1994-06-01

    Aluminium, silicon, copper, iron, magnesium and sulfur in Kalewa (Myanmar) coal were determined by fast neutron activation analysis. For activation a KAMAN A-710 Neutron Generator was used. Kalewa coal was found to be low in sulfur and relatively rich in iron. (author) 2 refs.; 1 fig.; 1 tab.

  6. Fast neutron activation analysis of Kalewa (Myanmar) coal

    International Nuclear Information System (INIS)

    Myint, U.; Naing, W.

    1994-01-01

    Aluminium, silicon, copper, iron, magnesium and sulfur in Kalewa (Myanmar) coal were determined by fast neutron activation analysis. For activation a KAMAN A-710 Neutron Generator was used. Kalewa coal was found to be low in sulfur and relatively rich in iron. (author) 2 refs.; 1 fig.; 1 tab

  7. Development of educational program for neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Sam; Moon, Jong Hwa; Kim, Sun Ha; Ryel, Sung; Kang, Young Hwan; Lee, Kil Yong; Yeon, Yeon Yel; Cho, Seung Yeon

    2000-08-01

    This technical report is developed to apply an educational and training program for graduate student and analyst utilizing neutron activation analysis. The contents of guide book consists of five parts as follows; introduction, gamma-ray spectrometry and measurement statistics, its applications, to understand of comprehensive methodology and to utilize a relevant knowledge and information on neutron activation analysis.

  8. Neutron activation analysis applied to energy and environment

    International Nuclear Information System (INIS)

    Lyon, W.S.

    1975-01-01

    Neutron activation analysis was applied to a number of problems concerned with energy production and the environment. Burning of fossil fuel, the search for new sources of uranium, possible presence of toxic elements in food and water, and the relationship of trace elements to cardiovascular disease are some of the problems in which neutron activation was used. (auth)

  9. Determination of average activating thermal neutron flux in bulk samples

    International Nuclear Information System (INIS)

    Doczi, R.; Csikai, J.; Doczi, R.; Csikai, J.; Hassan, F. M.; Ali, M.A.

    2004-01-01

    A previous method used for the determination of the average neutron flux within bulky samples has been applied for the measurements of hydrogen contents of different samples. An analytical function is given for the description of the correlation between the activity of Dy foils and the hydrogen concentrations. Results obtained by the activation and the thermal neutron reflection methods are compared

  10. Instrumental neutron activation analysis in environmental research

    International Nuclear Information System (INIS)

    Bruin, M. de.

    1985-01-01

    The main characteristics of instrumental neutron activation analysis (INAA),relevant for environmental research and monitoring, was reviewed and discussed-sensitivity, suitable for detection of many toxic elements, the low risks of contamination of element loss, lack of matrix effects, lack of light element interference except for 24 Na, capability for multi-element determination, comparatively low costs. A detailed description of the IRI analysis system for routine INAA is given. The system is based on the single comparator method of standartization to take full advantage of multi-element without preparation and use the trace element standards. Zinc was used as mono element standard, the element concentrations are calculated on the basis of 65 Zn and 69m Zn-activities. The irradiations were carried out in a thermal neutron flux of 1.10 13 n/cm 2 .s. The gamma spectra is converted into element concentrations using a set of dedicated software, performing the following functions: spectrum analysis and interpretation, comparison and combination of the intermediate results from different decay times, generation of the final report, bookkeeping of the results obtained. The main applications of the INAA system mentioned are: identification of sources of heavy metal air pollution using air filters or biological indicators such as mosses, lichens, toe-nails, bird feathers, molusks and waterplants; and study of the uptake and translocation of heavy element in plants. Special attention was paid to mathematical techniques for a reliable interpretation of the element concentration patterns observed in sets of lichen samples. Future developments in INAA in environmental science are briefly mentioned

  11. Neutron beams for therapy

    International Nuclear Information System (INIS)

    Kuplenikov, Eh.L.; Dovbnya, A.N.; Telegin, Yu.N.; Tsymbal, V.A.; Kandybej, S.S.

    2011-01-01

    It was given the analysis and generalization of the study results carried out during some decades in many world countries on application of thermal, epithermal and fast neutrons for neutron, gamma-neutron and neutron-capture therapy. The main attention is focused on the practical application possibility of the accumulated experience for the base creation for medical research and the cancer patients effective treatment.

  12. Neutron activation diagnostics at the National Ignition Facility (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Bleuel, D. L.; Yeamans, C. B.; Bernstein, L. A.; Bionta, R. M.; Caggiano, J. A.; Drury, O. B.; Hagmann, C. A.; Hatarik, R.; Knittel, K. M.; McNaney, J. M.; Moran, M.; Schneider, D. H. G. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Casey, D. T.; Frenje, J. A.; Johnson, M. Gatu [Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Cooper, G. W. [University of New Mexico, Albuquerque, New Mexico 87131 (United States); Knauer, J. P. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Leeper, R. J.; Ruiz, C. L. [Sandia National Laboratory, Albuquerque, New Mexico 87185 (United States)

    2012-10-15

    Neutron yields are measured at the National Ignition Facility (NIF) by an extensive suite of neutron activation diagnostics. Neutrons interact with materials whose reaction cross sections threshold just below the fusion neutron production energy, providing an accurate measure of primary unscattered neutrons without contribution from lower-energy scattered neutrons. Indium samples are mounted on diagnostic instrument manipulators in the NIF target chamber, 25-50 cm from the source, to measure 2.45 MeV deuterium-deuterium fusion neutrons through the {sup 115}In(n,n'){sup 115m} In reaction. Outside the chamber, zirconium and copper are used to measure 14 MeV deuterium-tritium fusion neutrons via {sup 90}Zr(n,2n), {sup 63}Cu(n,2n), and {sup 65}Cu(n,2n) reactions. An array of 16 zirconium samples are located on port covers around the chamber to measure relative yield anisotropies, providing a global map of fuel areal density variation. Neutron yields are routinely measured with activation to an accuracy of 7% and are in excellent agreement both with each other and with neutron time-of-flight and magnetic recoil spectrometer measurements. Relative areal density anisotropies can be measured to a precision of less than 3%. These measurements reveal apparent bulk fuel velocities as high as 200 km/s in addition to large areal density variations between the pole and equator of the compressed fuel.

  13. Comparison of neutron activation analysis techniques for the determination of uranium concentrations in geological and environmental materials

    International Nuclear Information System (INIS)

    Landsberger, S.; Kapsimalis, R.

    2013-01-01

    We have described the determination of uranium in environmental, geological, and agricultural specimens by three different non-destructive nuclear methods. The effectiveness, as defined as the lower limits of detection in this work, of quantifying trace levels of bulk uranium in geological samples was evaluated for several common NAA techniques. These techniques include short-lived and medium-lived neutron activation analysis using thermal and epithermal neutrons; these results were compared with an assessment of Compton suppressed gamma-ray counting. A careful evaluation of three major (n,γ) reactions with chlorine, manganese and sodium that could impede determining low levels of uranium due to high Compton continuums was done. The evaluation of Compton suppressed passive gamma counting revealed that uranium concentrations below 50 mg kg −1 were not adequate to achieve good counting statistics using the 234m Pa the second daughter product of 238 U. -- Highlights: ► Determination of uranium concentrations in geological, environmental, and agricultural specimens. ► Use of several NAA and passive counting methods. ► Identified several key interferences. ► Use of Compton suppression to minimize effects of interferences

  14. Atmospheric deposition of heavy metals in Serbia studied by moss biomonitoring, neutron activation analysis and GIS technology

    International Nuclear Information System (INIS)

    Frontas'eva, M.V.; Galinskaya, T.E.; Pavlov, S.S.; Kumar, M.; Matavuly, M.; Radnovic, D.; Steinnes, E.

    2002-01-01

    The results of a pilot study on atmospheric deposition of heavy metals and other trace elements using the moss biomonitoring technique in the northern part of Serbia and some areas of Bosnia are presented. Samples of Hypnum cupressiforme along with some other moss types were collected at 92 sites during the summer of 2000. A total of 44 elements were determined by instrumental neutron activation analysis using epithermal neutrons. The observed levels of Cu, Zn, As, Ag, Cd, In, Sb, etc. in the area surrounding the town of Bor (Serbia) are comparable to those reported from similar industrial areas in other countries such as the Copper Basin in Poland and the South Urals of Russia. In the same region the maximum Se and Mo concentrations are the highest ever recorded in biomonitoring studies using mosses. High median concentrations of Fe and Ni in Serbian mosses are associated with a crustal component as apparent from factor analysis of the moss data. This component could be a result of windblown soil dust (most of the samples were taken from agricultural regions) or deposition of ash from coal-burning power stations. Some specific elements such as Cl and V may originate from known industrial sources, but at certain places high values in the moss samples are suspected to be associated with fires in oil refineries damaged during the 1999 NATO military action

  15. Atmospheric Deposition of Heavy Metals in Serbia Studied by Moss Biomonitoring, Neutron Activation Analysis and GIS Technology

    CERN Document Server

    Frontasyeva, M V; Kumar, M; Matavuly, M; Pavlov, S S; Radnovic, D; Steinnes, E

    2002-01-01

    The results of a pilot study on atmospheric deposition of heavy metals and other trace elements using the moss biomonitoring technique in the northern part of Serbia and some areas of Bosnia are presented. Samples of Hypnum cupressiforme along with some other moss types were collected at 92 sites during the summer of 2000. A total of 44 elements were determined by instrumental neutron activation analysis using epithermal neutrons. The observed levels of Cu, Zn, As, Ag, Cd, In, Sb, etc. in the area surrounding the town of Bor (Serbia) are comparable to those reported from similar industrial areas in other countries such as the Copper Basin in Poland and the South Urals of Russia. In the same region the maximum Se and Mo concentrations are the highest ever recorded in biomonitoring studies using mosses. High median concentrations of Fe and Ni in Serbian mosses are associated with a crustal component as apparent from factor analysis of the moss data. This component could be a result of windblown soil dust (most ...

  16. Multielement analysis of human hair and kidney stones by instrumental neutron activation analysis with the k0-standardization method

    International Nuclear Information System (INIS)

    Abugassa, I.; Sarmani, S.B.; Samat, S.B.

    1999-01-01

    This paper focuses on the evaluation of the k 0 method of instrumental neutron activation analysis in biological materials. The method has been applied in multielement analysis of human hair standard reference materials from IAEA, No. 085, No. 086 and from NIES (National Institute for Environmental Sciences) No. 5. Hair samples from people resident in different parts of Malaysia, in addition to a sample from Japan, were analyzed. In addition, human kidney stones from members of the Malaysian population have been analyzed for minor and trace elements. More than 25 elements have been determined. The samples were irradiated in the rotary rack (Lazy Susan) at the TRIGA Mark II reactor of the Malaysian Institute for Nuclear Technology and Research (MINT). The accuracy of the method was ascertained by analysis of other reference materials, including 1573 tomato leaves and 1572 citrus leaves. In this method the deviation of the 1/E 1+α epithermal neutron flux distribution from the 1/E law (P/T ratio) for true coincidence effects of the γ-ray cascade and the HPGe detector efficiency were determined and corrected for

  17. The effect of cadmium shielding on the spatial neutron flux distribution inside one of the outer irradiation sites

    International Nuclear Information System (INIS)

    Shaaban, I.

    2009-06-01

    A permanent epithermal neutron irradiation facility was designed in the Syrian Miniature Neutron Source Reactor (MNSR) by using the cadmium (cylindrical vial 1.0 mm in thickness, 38.50 mm in diameter and 180 mm in length) as thermal neutron shielding material, for a permanent epithermal neutron activation analysis (ENAA). This site was designed by shielding the internal surface of the aluminum tube of the first outer irradiation site in the MNSR reactor. I was used the activation detectors 0.1143% Au-Al alloy foils with 0.1 mm thickness and 2.0 mm diameter for measurement the thermal neutron flux, epithermal and R c d=A b are/A c over ratio in the outer irradiation site. Distribution of the thermal neutron flux in the outer irradiation capsule has been found numerically using MCNP-4C code with and without cadmium shield, and experimentally by irradiating five copper wires using the outer irradiation capsule. Good agreements were obtained between the calculated and the measured results. (author)

  18. Preparation of the in-house neutron detectors and the software needed to process experimental data

    International Nuclear Information System (INIS)

    Haddad, Kh.; Haj-Hassan, H.; Helal, W.

    2007-04-01

    In - house neutron activation detectors were prepared in this work using pure commercial gold. The neutron self-shielding factors in the foils for both thermal and epithermal neutrons have been determined experimentally. The work shows good results repeatability and good agreement with certified activation monitors. the software KHW for neutron flux measurements using local and standards gold foils was designed and performed locally. it deals as well with irradiated uranium spectrums to calculate some important fission product ratios for neutron flux measurement. Some experiments were performed to investigate the possibility of using uranium, produced in the pilot plant, as fission neutron detector. The results shows the possibility of using fission product ratios to determine the cooling time of the samples. It shows also the possibility of using fission and activation product ratios as an indicators of neutron fluences ratios.(author)

  19. Determination of silver, gold, zinc and copper in mineral samples by various techniques of instrumental neutron activation analysis; Determinacion de plata, oro, zinc y cobre en muestras minerales mediante diversas tecnicas de analisis por activacion de neutrones instrumental

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez R, N. I.; Rios M, C.; Pinedo V, J. L. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Yoho, M.; Landsberger, S., E-mail: neisla126@hotmail.com [University of Texas at Austin, Nuclear Engineering Teaching Laboratory, Austin 78712, Texas (United States)

    2015-09-15

    Using the method of instrumental neutron activation analysis, mineral exploration samples were analyzed in order to determine the concentrations of silver, gold, zinc and copper; these minerals being the main products of benefit of Tizapa and Cozamin mines. Samples were subjected to various techniques, where the type of radiation and counting methods were chosen based on the specific isotopic characteristics of each element. For calibration and determination of concentrations the comparator method was used, certified standards were subjected to the same conditions of irradiation and measurement that the prospecting samples. The irradiations were performed at the research reactor TRIGA Mark II of the University of Texas at Austin. The silver concentrations were determined by Cyclical Epithermal Neutron Activation Analysis. This method in combination with the transfer pneumatic system allowed a good analytical precision and accuracy in prospecting for silver, from photo peak measurement 657.7 keV of short half-life radionuclide {sup 110}Ag. For the determination of gold and zinc, Epithermal Neutron Activation Analysis was used, the photo peaks analyzed corresponded to the energies 411.8 keV of radionuclide {sup 199}Au and 438.6 keV of metastable radionuclide {sup 69m}Zn. On the other hand, copper quantification was based on the photo peak analysis of 1039.2 keV produced by the short half-life radionuclide {sup 66}Cu, by Thermal Neutron Activation Analysis. The photo peaks measurement corresponding to gold, zinc and copper was performed using a Compton suppression system, which allowed an improvement in the signal to noise relationship, so that better detection limits and low uncertainties associated with the results were obtained. Comparing elemental concentrations the highest values in silver, zinc and copper was for samples of mine Tizapa. Regarding gold values were found in the same range for both mines. To evaluate the precision and accuracy of the methods used

  20. Triga IPR-R1 neutron beam: increasing the thematic of applications in CDTN

    International Nuclear Information System (INIS)

    Sebastiao, Rita de C.O.; Rodrigues, Rogerio R.; Leal, Alexandre S.

    2007-01-01

    The neutron flux in a research reactor can be used in several applications such as the neutron activation analysis, the radioisotopes production, study of DNA and protein structures, doping of silicon and neutron radiography. The enhancement of the nuclear research reactor utilization with the introduction of new applications would be possible with the availability of a neutron beam and with the neutron energy spectra completely characterized. This work evaluates the use of TRIGA reactor of CDTN/CNEN as a source of neutron beam. The readiness of a neutron beam with appropriate intensity and energy spectrum would make possible the increasing of the thematic of applications and researches in this reactor. The main contribution to this theme is to evaluate the thermal and epithermal neutron flux in the vertical extractor of the TRIGA IPR-R1. The simulation was performed in this work using the MCNP code. (author)

  1. Neutron activation analysis at the Californium User Facility for Neutron Science

    International Nuclear Information System (INIS)

    Martin, R.C.; Smith, E.H.; Glasgow, D.C.; Jerde, E.A.; Marsh, D.L.; Zhao, L.

    1997-12-01

    The Californium User Facility (CUF) for Neutron Science has been established to provide 252 Cf-based neutron irradiation services and research capabilities including neutron activation analysis (NAA). A major advantage of the CUF is its accessibility and controlled experimental conditions compared with those of a reactor environment The CUF maintains the world's largest inventory of compact 252 Cf neutron sources. Neutron source intensities of ≤ 10 11 neutrons/s are available for irradiations within a contamination-free hot cell, capable of providing thermal and fast neutron fluxes exceeding 10 8 cm -2 s -1 at the sample. Total flux of ≥10 9 cm -2 s -1 is feasible for large-volume irradiation rabbits within the 252 Cf storage pool. Neutron and gamma transport calculations have been performed using the Monte Carlo transport code MCNP to estimate irradiation fluxes available for sample activation within the hot cell and storage pool and to design and optimize a prompt gamma NAA (PGNAA) configuration for large sample volumes. Confirmatory NAA irradiations have been performed within the pool. Gamma spectroscopy capabilities including PGNAA are being established within the CUF for sample analysis

  2. Neutron spectrum determination by activation method in fast neutron fields at the RB reactor

    International Nuclear Information System (INIS)

    Sokcic-Kostic, M.; Pesic, M.; Antic, D.

    1994-01-01

    The fast neutron fields of the RB reactor are presented in this paper. The activation method for spectrum determination is described and explained. The obtained results for intermediate and fast spectrum are given and discussed. (author)

  3. Neutron spectrum determination by activation method in fast neutron fields at the RB reactors

    International Nuclear Information System (INIS)

    Sokcic-Kostic, M.S.; Pesic, M.P.; Antic, D.P.

    1994-01-01

    The fast neutron fields of the RB reactor are presented in this paper. The activation method for spectrum determination is described and explained. The obtained results for intermediate and fast spectrum are given and discussed. (authors). 7 refs., 3 tabs

  4. Techniques of in vivo neutron activation analysis

    International Nuclear Information System (INIS)

    Chettle, D.R.; Fremlin, J.H.

    1984-01-01

    This review is dealt with under the following headings, intended to reflect the different factors affecting the measurement sensitivity, starting with the choice of neutron source and proceeding, through the reaction characteristics, to the detection system, the questions of dosimetry and ethical constraints being also discussed: 1) neutron sources, slowing down and interaction processes, energy spectrum and flux uniformity, timing 2) neutron reactions used for in vivo analyses 3) detectors, choice, geometrical considerations and detector shielding 4) data collection and processing 5) interpretation, major elements, absolute or sequential measurements, relationship to other parameters 6) dosimetry, framework for dose levels, biological effects of neutron interactions, neutron doses in practice 7) implications for measurement of calcium, nitrogen and cadmium. (U.K.)

  5. Activation analysis opportunities using cold neutron beams

    Energy Technology Data Exchange (ETDEWEB)

    Lindstrom, R M; Zeisler, R; Rossbach, M

    1987-05-01

    Guided beams of cold neutrons being installed at a number of research reactors may become increasingly available for analytical research. A guided cold beam will provide higher neutron fluence rates and lower background interferences than in present facilities. In an optimized facility, fluence rates of 10/sup 9/ nxcm/sup -2/xs/sup -1/ are obtainable. Focusing a large area beam onto a small target will further increase the neutron intensity. In addition, the shift to lower neutron energy increases the effective cross sections. The absence of fast neutrons and gamma rays permits detectors to be placed near the sample without intolerable background, and thus the efficiency for counting prompt gamma rays can be much higher than in present systems. Measurements made at the hydrogen cold source of the FRJ-2 (DIDO) reactor at the KFA provide a numerical evaluation of the improvements in PGAA with respect to signal-to-background ratios of important elements and matrices. (author) 15 refs.

  6. Neutron activation of building materials used in the reactor shield

    International Nuclear Information System (INIS)

    Hernandez, A.T.; Perez, G.; D'Alessandro, K.

    1993-01-01

    Cuban concretes and their main components (mineral aggregates and cement) were investigated through long-lived activation products induced by neutrons from a reactor. The multielemental content in the materials studied was obtained by neutron activation analysis in an IBR-2 reactor and gamma activation analysis in an MT-25 microtron from Join Institute of Nuclear Research of Dubna. After irradiation of building materials for 30 years by a neutron flow of unitary density, induced radioactivity was calculated according to experimental data. The comparative evaluation of different concretes aggregates and two types of cement related to the activation properties is discussed

  7. Fast neutron activation analysis at Texas A and M University

    International Nuclear Information System (INIS)

    James, W.D.

    1997-01-01

    Fast neutron generators are used at Texas A and M University to provide a supply of high energy neutrons for nuclear analytical measurements. A series of neutron activation analysis procedures have been developed for determining various major, minor and trace constituents in a variety of materials. These procedures are primarily developed to compliment our reactor based NAA program, thereby expanding the list of determinable elements to include those difficult or impossible to measure using thermal neutrons. A few typical methods are discussed. The unique implementation of the methodologies at Texas A and M are explained. (author)

  8. Fissile materials in solution concentration measured by active neutron interrogation

    International Nuclear Information System (INIS)

    Romeyer Dherbey, J.; Passard, Ch.; Cloue, J.; Bignan, G.

    1993-01-01

    The use of the active neutron interrogation to measure the concentration of plutonium contained in flow solutions is particularly interesting for fuel reprocessing plants. Indeed, this method gives a signal which is in a direct relation with the fissile materials concentration. Moreover, it is less sensitive to the gamma dose rate than the other nondestructive methods. Two measure methods have been evolved in CEA. Their principles are given into details in this work. The first one consists to detect fission delayed neutrons induced by a 252 Cf source. In the second one fission prompt neutrons induced by a neutron generator of 14 MeV are detected. (O.M.)

  9. Neutron activation analysis (NAA), radioisotope production via neutron activation (PNA) and fission product gas-jet (GJA)

    Energy Technology Data Exchange (ETDEWEB)

    Gaeggeler, H W [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-11-01

    Three different non-diffractive applications of neutrons are outlined, neutron activation analysis, production of radionuclides, mostly for medical applications, and production of short-lived fission nuclides with a so-called gas-jet. It is shown that all three devices may be incorporated into one single insert at SINQ due to their different requests with respect to thermal neutron flux. Some applications of these three facilities are summarized. (author) 3 figs., 1 tab., 8 refs.

  10. Neutron activation analysis (NAA), radioisotope production via neutron activation (PNA) and fission product gas-jet (GJA)

    International Nuclear Information System (INIS)

    Gaeggeler, H.W.

    1996-01-01

    Three different non-diffractive applications of neutrons are outlined, neutron activation analysis, production of radionuclides, mostly for medical applications, and production of short-lived fission nuclides with a so-called gas-jet. It is shown that all three devices may be incorporated into one single insert at SINQ due to their different requests with respect to thermal neutron flux. Some applications of these three facilities are summarized. (author) 3 figs., 1 tab., 8 refs

  11. Neutron activation analysis of arsenic in Greece

    International Nuclear Information System (INIS)

    Grimanis, A.P.

    1989-01-01

    Arsenic is considered a toxic trace element for plant, animal, and human organisms. Arsenic and certain arsenic compounds have been listed as carcinogens by the U.S. Environmental Protection Agency. Arsenic is emitted in appreciable quantities into the atmosphere by coal combustion and the production of cement. Arsenic enters the aquatic environment through industrial activities such as smelting of metallic ores, metallurgical glassware, and ceramics as well as insecticide production and use. Neutron activation analysis (NAA) is a very sensitive, precise, and accurate method for determining arsenic. This paper is a review of research studies of arsenic in the Greek environment by NAA performed at our radioanalytical laboratory. The objectives of these studies were (a) to determine levels of arsenic concentrations in environmental materials, (b) to pinpoint arsenic pollution sources and estimate the extent of arsenic pollution, and (c) to find out whether edible marine organisms from the gulfs of Greece receiving domestic, industrial, and agricultural wastes have elevated concentrations of arsenic in their tissues that could render them dangerous for human consumption

  12. New experimental research stand SVICKA neutron field analysis using neutron activation detector technique

    Science.gov (United States)

    Varmuza, Jan; Katovsky, Karel; Zeman, Miroslav; Stastny, Ondrej; Haysak, Ivan; Holomb, Robert

    2018-04-01

    Knowledge of neutron energy spectra is very important because neutrons with various energies have a different material impact or a biological tissue impact. This paper presents basic results of the neutron flux distribution inside the new experimental research stand SVICKA which is located at Brno University of Technology in Brno, Czech Republic. The experiment also focused on the investigation of the sandwich biological shielding quality that protects staff against radiation effects. The set of indium activation detectors was used to the investigation of neutron flux distribution. The results of the measurement provide basic information about the neutron flux distribution inside all irradiation channels and no damage or cracks are present in the experimental research stand biological shielding.

  13. Ten year's activity in the field of neutron scattering workshop

    International Nuclear Information System (INIS)

    Hamaguchi, Yoshikazu

    2003-01-01

    'Neutron scattering' is in the frame of the 'Utilization of Research Reactor's of the FNCA (Forum for Nuclear Cooperation in Asia) project, which held the workshops from FY 1992. This report is a summary of the results and activities of neutron scattering workshops and sub-workshops since the start in FY 1992. (author)

  14. Progress in small angle neutron scattering activities in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Abudl Aziz Bin [Industrial Technology Division, Malaysian Institute for Nuclear Technology Research (MINT) (Indonesia)

    2000-10-01

    Research activities by use of small angle neutron scattering in Malaysia are briefly reported. Scattered neutron data are displayed in two or three-dimensional isometric view by the data acquisition system. Visual Basic is utilized for data acquisition and MathCad for data processing and analyses. (Y. Kazumata)

  15. Progress in small angle neutron scattering activities in Malaysia

    International Nuclear Information System (INIS)

    Mohamed, Abudl Aziz Bin

    2000-01-01

    Research activities by use of small angle neutron scattering in Malaysia are briefly reported. Scattered neutron data are displayed in two or three-dimensional isometric view by the data acquisition system. Visual Basic is utilized for data acquisition and MathCad for data processing and analyses. (Y. Kazumata)

  16. Neutron flux parameters for k{sub 0}-NAA method at the Malaysian nuclear agency research reactor after core reconfiguration

    Energy Technology Data Exchange (ETDEWEB)

    Yavar, A.R. [School of Applied Physics, Faculty of Science and Technology, University Kebangsaan Malaysia (UKM), Bangi, Selangor 43600 (Malaysia); Sarmani, S. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, University Kebangsaan Malaysia (UKM), Bangi, Selangor 43600 (Malaysia); Wood, A.K. [Analytical Chemistry Application Group, Industrial Technology Division, Malaysian Nuclear Agency (MNA), Bangi, Kajang, Selangor 43000 (Malaysia); Fadzil, S.M. [School of Applied Physics, Faculty of Science and Technology, University Kebangsaan Malaysia (UKM), Bangi, Selangor 43600 (Malaysia); Masood, Z. [Analytical Chemistry Application Group, Industrial Technology Division, Malaysian Nuclear Agency (MNA), Bangi, Kajang, Selangor 43000 (Malaysia); Khoo, K.S., E-mail: khoo@ukm.m [School of Applied Physics, Faculty of Science and Technology, University Kebangsaan Malaysia (UKM), Bangi, Selangor 43600 (Malaysia)

    2011-02-15

    The Malaysian Nuclear Agency (MNA) research reactor, commissioned in 1982, is a TRIGA Mark II swimming pool type reactor. When the core configuration changed in June 2009, it became essential to re-determine such neutron flux parameters as thermal to epithermal neutron flux ratio (f), epithermal neutron flux shape factor ({alpha}), thermal neutron flux ({phi}{sub th}) and epithermal neutron flux ({phi}{sub epi}) in the irradiation positions of MNA research reactor in order to guarantee accuracy in the application of k{sub 0}-neutron activation analysis (k{sub 0}-NAA).The f and {alpha} were determined using the bare bi-isotopic monitor and bare triple monitor methods, respectively; Au and Zr monitors were utilized in present study. The results for four irradiation positions are presented and discussed in the present work. The calculated values of f and {alpha} ranged from 33.49 to 47.33 and -0.07 to -0.14, respectively. The {phi}{sub th} and the {phi}{sub epi} were measured as 2.03 x 10{sup 12} (cm{sup -2} s{sup -1}) and 6.05 x 10{sup 10} (cm{sup -2} s{sup -1}) respectively. These results were compared to those of previous studies at this reactor as well as to those of reactors in other countries. The results indicate a good conformity with other findings.

  17. A Dosimetry Study of Deuterium-Deuterium Neutron Generator-based In Vivo Neutron Activation Analysis.

    Science.gov (United States)

    Sowers, Daniel; Liu, Yingzi; Mostafaei, Farshad; Blake, Scott; Nie, Linda H

    2015-12-01

    A neutron irradiation cavity for in vivo neutron activation analysis (IVNAA) to detect manganese, aluminum, and other potentially toxic elements in human hand bone has been designed and its dosimetric specifications measured. The neutron source is a customized deuterium-deuterium neutron generator that produces neutrons at 2.45 MeV by the fusion reaction 2H(d, n)3He at a calculated flux of 7 × 10(8) ± 30% s(-1). A moderator/reflector/shielding [5 cm high density polyethylene (HDPE), 5.3 cm graphite and 5.7 cm borated (HDPE)] assembly has been designed and built to maximize the thermal neutron flux inside the hand irradiation cavity and to reduce the extremity dose and effective dose to the human subject. Lead sheets are used to attenuate bremsstrahlung x rays and activation gammas. A Monte Carlo simulation (MCNP6) was used to model the system and calculate extremity dose. The extremity dose was measured with neutron and photon sensitive film badges and Fuji electronic pocket dosimeters (EPD). The neutron ambient dose outside the shielding was measured by Fuji NSN3, and the photon dose was measured by a Bicron MicroREM scintillator. Neutron extremity dose was calculated to be 32.3 mSv using MCNP6 simulations given a 10-min IVNAA measurement of manganese. Measurements by EPD and film badge indicate hand dose to be 31.7 ± 0.8 mSv for neutrons and 4.2 ± 0.2 mSv for photons for 10 min; whole body effective dose was calculated conservatively to be 0.052 mSv. Experimental values closely match values obtained from MCNP6 simulations. These are acceptable doses to apply the technology for a manganese toxicity study in a human population.

  18. Mock-up experiment at Birmingham University for BNCT project of Osaka University – Neutron flux measurement with gold foil

    International Nuclear Information System (INIS)

    Tamaki, S.; Sakai, M.; Yoshihashi, S.; Manabe, M.; Zushi, N.; Murata, I.; Hoashi, E.; Kato, I.; Kuri, S.; Oshiro, S.; Nagasaki, M.; Horiike, H.

    2015-01-01

    Mock-up experiment for development of accelerator based neutron source for Osaka University BNCT project was carried out at Birmingham University, UK. In this paper, spatial distribution of neutron flux intensity was evaluated by foil activation method. Validity of the design code system was confirmed by comparing measured gold foil activities with calculations. As a result, it was found that the epi-thermal neutron beam was well collimated by our neutron moderator assembly. Also, the design accuracy was evaluated to have less than 20% error. - Highlights: • Accelerator based neutron source for BNCT is being developed in Osaka University. • Mock-up experiment was carried out at Birmingham University, UK. • Neutronics performance of our assembly was evaluated from gold foil activation. • Gold foil activation was determined by using HPGe detectors. • Validity of the neutronics design code system was confirmed.

  19. Characterisation of some exotic fruits (Morus nigra, Morus alba, Salvadora persica and Carissa opaca) used as herbal medicines by neutron activation analysis and estimation of their nutritional value

    International Nuclear Information System (INIS)

    Mohammad Wasim; Muhammad Daud; Mohammad Arif; Sajid Iqbal; Yasir Anwar

    2012-01-01

    In the under developed countries, the people of far-flung rural areas still depend to a large extent upon herbal medicines. At the foundation of usage of herbal medicine is the experience of thousands of years. The present paper deals with the characterisation of exotic fruits for essential and toxic elements. The samples include Morus nigra, Morus alba, Salvadora persica and Carissa opaca (from low and high altitude). Two standardizations of neutron activation analysis, that is, semi-absolute k 0-instrumental neutron activation analysis (k 0 -INAA) and epithermal neutron activation analysis (ENAA) were employed for the quantification of elements. The analysis methodologies were validated by analyzing the IAEA-336 (lichen) and NIST-SRM-1572 (citrus leaves). Sixteen elements including Br, Ca, Cl, Co, Cr, Fe, I, K, Mg, Mn, Na, Rb, Sb, Sc Sr, and Zn were determined in all samples. Daily intakes of various elements from the samples were measured and compared with the dietary reference intakes. Additionally, principal component analysis was performed to extract information regarding samples and elements. (author)

  20. Neutron flux measurements in PUSPATI Triga Reactor

    International Nuclear Information System (INIS)

    Gui Ah Auu; Mohamad Amin Sharifuldin Salleh; Mohamad Ali Sufi.

    1983-01-01

    Neutron flux measurement in the PUSPATI TRIGA Reactor (PTR) was initiated after its commissioning on 28 June 1982. Initial measured thermal neutron flux at the bottom of the rotary specimen rack (rotating) and in-core pneumatic terminus were 3.81E+11 n/cm 2 sec and 1.10E+12n/cm 2 sec respectively at 100KW. Work to complete the neutron flux data are still going on. The cadmium ratio, thermal and epithermal neutron flux are measured in the reactor core, rotary specimen rack, in-core pneumatic terminus and thermal column. Bare and Cadmium covered gold foils and wires are used for the above measurement. The activities of the irradiated gold foils and wires are determined using Ge(Li) and hyperpure germinium detectors. (author)

  1. Radiochemical and instrumental neutron activation analysis - recent trends

    International Nuclear Information System (INIS)

    Dams, R.

    1990-01-01

    Recent trends of radiochemical and instrumental neutron activation analysis are discussed. Novel developments include the application of cyclic and pulsed activation, better energy resolution with hyperpure germanium detectors, and use of pulse processing systems allowing extremely high count rates of very short-lived isotopes. Further development is anticipated in the field of speciation in biological and environmental studies. Radiochemical methods have led to accurate determinations at the ng/g level. A promising future is expected for neutron activation techniques. (orig.)

  2. The synchronous active neutron detection system for spent fuel assay

    International Nuclear Information System (INIS)

    Pickrell, M.M.; Kendall, P.K.

    1994-01-01

    The authors have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit the unique operating features of a 14-MeV neutron generator developed by Schlumberger. This generator and a novel detection system will be applied to the direct measurement of the fissile material content in spent fuel in place of the indirect measures used at present. The technique they are investigating is termed synchronous active neutron detection (SAND). It closely follows a method that has been used routinely in other branches of physics to detect very small signals in the presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed open-quotes lock-inclose quotes amplifiers. The authors have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. This approach is possible because the Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. The results to date are preliminary but quite promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly. It also appears to be quite resilient to background neutron interference. The interrogating neutrons appear to be nonthermal and penetrating. Although a significant amount of work remains to fully explore the relevant physics and optimize the instrument design, the underlying concept appears sound

  3. Instrumental neutron activation analysis of brewer's yeast

    International Nuclear Information System (INIS)

    Bergerioux, C.; Zikovsky, L.

    1978-01-01

    Instrumental neutron activation was used for the determination of 23 trace and minor elements in 4 different samples of brewer's yeast. Detection limits vary from 2 ppb to 100 ppm. The following average concentrations were found (ppm, dry weight): Al 597, Br 0.36, Cl 1473, Co 0.21, Cu 19, Fe 285, K 16400, Mg 1355, Mn 8.4, Na 2330, Rb 19, Sb 0.053, Se 1.2, V 2.2 and Zn 80. NBS standard 1569 was also analyzed and the following concentrations (in ppm) were measured: Al 2300, Br 0.65, Ce 0.23, Cl 460, Co 0.26, Cr 2.12, Cu 11, Fe 707, Gd 7.1, Hf 0.13, K 15500, Mg 1780, Mn 7, Na 510, Rb 16, Sb 0.075, Sc 0.18, Se 0.92, Th 3.7, Ti 38, U 0.49, V 4.1 and Zn 70. (author)

  4. Substoichiometric neutron activation determination of gold

    International Nuclear Information System (INIS)

    Mitchell, J.W.; Riley, J.E. Jr.; Payne, V.

    1978-01-01

    A highly precise and selective method is described for the determination of traces of gold by substoichiometric extraction from hydrochloric acid with tri-n-octylphosphine sulfide in cyclohexane following thermal neutron activation. Fundamental aspects of the extraction system are discussed and results are reported for the determination of gold in an effluent from a recovery process containing a complexed species of gold and unknown amounts of cyanide, citrate, phosphate, potassium and sodium. Other constituents of the effluent stream include traces of the transition elements Co, Ni, Fe, Cu, Zn, Pb and Sn at concentrations less than 50 ppm. One hour was allowed for the Au 3+ carrier and the 198 Au complexed species in samples and standards to oxidize, exchange, and reach chemical equilibrium. Samples were then equilibrated by shaking with the organic phase for thirty min. The percentage extractions (%E) for the substoichiometric separation of gold from the effluent and from the corresponding comparison standards were monitored. The mean percentage extractions for the substoichiometric separations of carrier from the effluent, and its corresponding standard were 75.3 and 59.3, respectively. These data are estimated to be accurate within +-2.0%. (T.G.)

  5. Neutron activation analysis of limestone objects

    International Nuclear Information System (INIS)

    Meyers, P.; Van Zelst, L.

    1977-01-01

    The elemental composition of samples from limestone objects were determined by neutron activation analysis to investigate whether this technique can be used to distinguish between objects made of limestone from different sources. Samples weighing between 0.2-2 grams were obtained by drilling from a series of ancient Egyptian and medieval Spanish objects. Analysis was performed on aliquots varying in weight from 40-100 milligrams. The following elements were determined quantitatively: Na, K, Rb, Cs, Ba, Sc, La, Ce, Sm, Eu, Hf, Th, Ta, Cr, Mn, Fe, Co and Zn. The data on Egyptian limestones indicate that, because of the inhomogeneous nature of the stone, 0.2-2 gram samples may not be representative of an entire object. Nevertheless, multivariate statistical methods produced a clear distinction between objects originating from the Luxor area (ancient Thebes) and objects found north of Luxor. The Spanish limestone studied appeared to be more homogeneous. Samples from stylistically related objects have similar elemental compositions while relative large differences were observed between objects having no relationship other than the common provenance of medieval Spain. (orig.) [de

  6. Chart of nuclides relating to neutron activation

    International Nuclear Information System (INIS)

    Okada, Minoru

    1981-09-01

    This chart is for frequent use in the prediction of the product species of neutron activation. The first edition of the chart has been made in 1976 after the repeated trial preparation. It has the following good points. (1) Any letter in chart is as large as one can read easily. [This condition has been obtained by the selection of items to be shown in chart. They are the name (the symbol of element, mass number, and half-life) of nuclide or of isomer, and the type of decay.]. (2) Decay product has been shown indirectly for branchings with two-step decay via short-lived daughter in an excited state. [This matter has been realized by use of the new mode of indication.] (3) Nuclides shown in chart are (a) naturally occurring nuclides and (b) nuclides formed from naturally occurring nuclides through one of the following reactions: (n, γ), (n, n'), (n, p), (n, α), (n, 2n), (n, pn), (n, 3n), (n, αn), (n, t), (n, 3 He), (n, 2p), and (n, γ)(n, γ). In the revision of the first edition, some modes of indication have become a little simpler, and the isomers of shorter half-lives (0.1 - 1 μs) have been added. (author)

  7. Quality assurance in neutron activation analysis

    International Nuclear Information System (INIS)

    Heydorn, K.

    1984-01-01

    As a potential reference method, neutron activation analysis does not have to rely on other reference materials to ascertain the quality of analytical results. The fundamental characteristics of the method with the clear separation between irradiation, processing, and counting makes possible the estimation of uncertainties of individual results from a priori assumptions. Such estimates of the standard deviation from a series of independent sources of variation are compared with the a posteriori variability of replicate determinations in order to ascertain that the analytical method is in a state of statistical control. This Analysis of Precision tests the absence of unknown errors by means of a statistic T, which is closely approximated by a chi-square distribution. In this manner an evaluation is made of a commercially available computer program for peak evaluation in γ-spectrometry, as well as of other factors affecting the precision and accuracy of the counting process. An attempt is also made to determine sampling constants of one gram or less in a candidate biological reference material

  8. Simultaneous thermal neutron decay time and porosity logging system

    International Nuclear Information System (INIS)

    Smith, H.D. Jr.; Smith, M.P.; Schultz, W.E.

    1979-01-01

    A simultaneous pulsed neutron porosity and thermal neutron capture cross section logging system is provided for radiological well logging of subsurface earth formations. A logging tool provided with a 14 MeV pulsed neutron source, an epithermal neutron detector, and a combination gamma ray and fast neutron detector is moved through a borehole. Repetitive bursts of neutrons irradiate the earth formations; and, during the bursts, the fast neutron and epithermal neutron populations are sampled. During the interval between bursts the thermal neutron capture gamma ray population is sampled in two or more time intervals. The fast and epithermal neutron population measurements are combined to provide a measurement of formation porosity phi. The capture gamma ray measurements are combined to provide a simultaneous determination of the thermal neutron capture cross section Σ

  9. Design considerations for neutron activation and neutron source strength monitors for ITER

    International Nuclear Information System (INIS)

    Barnes, C.W.; Jassby, D.L.; LeMunyan, G.; Roquemore, A.L.

    1997-01-01

    The International Thermonuclear Experimental Reactor will require highly accurate measurements of fusion power production in time, space, and energy. Spectrometers in the neutron camera could do it all, but experience has taught us that multiple methods with redundancy and complementary uncertainties are needed. Previously, conceptual designs have been presented for time-integrated neutron activation and time-dependent neutron source strength monitors, both of which will be important parts of the integrated suite of neutron diagnostics for this purpose. The primary goals of the neutron activation system are: to maintain a robust relative measure of fusion energy production with stability and wide dynamic range; to enable an accurate absolute calibration of fusion power using neutronic techniques as successfully demonstrated on JET and TFTR; and to provide a flexible system for materials testing. The greatest difficulty is that the irradiation locations need to be close to plasma with a wide field of view. The routing of the pneumatic system is difficult because of minimum radius of curvature requirements and because of the careful need for containment of the tritium and activated air. The neutron source strength system needs to provide real-time source strength vs. time with ∼1 ms resolution and wide dynamic range in a robust and reliable manner with the capability to be absolutely calibrated by in-situ neutron sources as done on TFTR, JT-60U, and JET. In this paper a more detailed look at the expected neutron flux field around ITER is folded into a more complete design of the fission chamber system

  10. The main results of the USSR neutron data activities in 1986-1987

    International Nuclear Information System (INIS)

    Manokhin, V.N.

    1988-01-01

    The report gives a review of the main results of neutron data activities in USSR and the activity of Nuclear Data Center in 1986-1987, namely concerning the experimental neutron data, the evaluated neutron data and the theoretical work

  11. Activation measurements for thermal neutrons. Part J. Evaluation of thermal neutron transmission factors

    International Nuclear Information System (INIS)

    Egbert, Stephen D.

    2005-01-01

    In order to relate thermal neutron activation measurements in samples to the calculated free-in-air thermal neutron activation levels given in Chapter 3, use is made of sample transmission factors. Transmission factors account for the modification of the fluence and activation at each sample's in situ location. For the purposes of this discussion, the transmission factor (TF) is defined as the ratio of the in situ sample activation divided by the free-in-air (FIA) activation at a height of 1 m above ground at the same ground range. The procedures for calculation of TF's and example results are presented in this section. (author)

  12. Critical elements in Carlin, epithermal, and orogenic gold deposits

    Science.gov (United States)

    Goldfarb, Richard J.; Hofstra, Albert H.; Simmons, Stuart F.

    2016-01-01

    Carlin, epithermal, and orogenic gold deposits, today mined almost exclusively for their gold content, have similar suites of anomalous trace elements that reflect similar low-salinity ore fluids and thermal conditions of metal transport and deposition. Many of these trace elements are commonly referred to as critical or near-critical elements or metals and have been locally recovered, although typically in small amounts, by historic mining activities. These elements include As, Bi, Hg, In, Sb, Se, Te, Tl, and W. Most of these elements are now solely recovered as by-products from the milling of large-tonnage, base metal-rich ore deposits, such as porphyry and volcanogenic massive sulfide deposits.A combination of dominance of the world market by a single country for a single commodity and a growing demand for many of the critical to near-critical elements could lead to future recovery of such elements from select epithermal, orogenic, or Carlin-type gold deposits. Antimony continues to be recovered from some orogenic gold deposits and tellurium could potentially be a primary commodity from some such deposits. Tellurium and indium in sphalerite-rich ores have been recovered in the past and could be future commodities recovered from epithermal ores. Carlin-type gold deposits in Nevada are enriched in and may be a future source for As, Hg, Sb, and/or Tl. Some of the Devonian carbonaceous host rocks in the Carlin districts are sufficiently enriched in many trace elements, including Hg, Se, and V, such that they also could become resources. Thallium may be locally enriched to economic levels in Carlin-type deposits and it has been produced from Carlin-like deposits elsewhere in the world (e.g., Alsar, southern Macedonia; Lanmuchang, Guizhou province, China). Mercury continues to be recovered from shallow-level epithermal deposits, as well as a by-product of many Carlin-type deposits where refractory ore is roasted to oxidize carbon and pyrite, and mercury is then

  13. Neutron activation analysis of some building materials

    International Nuclear Information System (INIS)

    Salagean, M.; Pantelica, A.; Georgescu, I.I.; Muntean, M.I.

    1999-01-01

    Over the past decade, indoor air quality has become a growing environmental problem. A careful selection of building materials concerning the acceptance of chemical and radioactive emissions is one of the ways to ensure high indoor air quality. Nowadays, it is a tendency to obtain new building materials having good isolation properties and low density by using the cheap and practically inexhaustible solid waste products like furnace slag, fly coal ash and phosphogypsum, without combustion. The Romanian furnace slag containing generally, above 45 % CaO can be used alone or mixed with fly ash to obtain some binder materials with mechanical resistance comparable to the Portland cement. Different additives such as CaO+Na 2 SO 4 or CaCl 2 +Na 2 SO 4 are used as activating admixtures. Concentrations of As, Au, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Mo, Na, Nd, Rb, Sb, Sc, Sr, Ta, Tb, Th, U, Yb, W and Zn in seven Romanian building materials were determined by Instrumental Neutron Activation Analysis (INAA) method at WWR-S Reactor of IFIN-HH, Bucharest. Raw material used in the cement production (∼75 % limestone, ∼25 % clay), cement samples from three different factories, furnace slag, phosphogypsum, and a type of brick compacted from furnace slag, fly coal ash, phosphogypsum, lime and cement have been analyzed. The fly coal ashes from five Romanian coal-fired power plants, resulting by the combustion of the xyloide brown coals, lignite and bituminous-subbituminous coals were previously analyzed. It was found that the content of the toxic microelements like As, Co, Cr, Th, U, Zn in the ceramic blocks is especially due to the slag and fly ash, the main components. This content depends on the particular sources of mineral raw materials. The presence of U, Th and K in slag is mainly correlated with the limestone and dolomite as used in the metallurgical process. (authors)

  14. Neutron Research in HANARO

    International Nuclear Information System (INIS)

    Kim, Hark Rho

    2005-01-01

    HANARO (High-flux Advanced Neutron Application Reactor), which was designed and constructed by indigenous technology, is a world-class multi-purpose research reactor with a design thermal power of 30 MW, providing high neutron flux for various applications in Korea. HANARO has been operated since its first criticality in February 1995, and is now successfully utilized in such areas as neutron beam research, fuel and materials tests, radioisotopes and radiopharmaceuticals production, neutron activation analysis, and neutron transmutation doping, etc. A number of experimental facilities have been developed and installed since the beginning of reactor operation, and R and D activities for installing more facilities are actively under progress. Three flux traps in the core (CT, IR1, IR2), providing a high fast neutron flux, can be used for materials and fuel irradiation tests. They are also proper for production of high specific activity radioisotopes. Four vertical holes in the outer core region, abundant in epithermal neutrons, are used for fuel or material tests and radioisotope production. In the heavy water reflector region, 25 vertical holes with high quality thermal neutrons are located for radioisotope production, neutron activation analysis, neutron transmutation doping and cold neutron source installation. The two largest holes named NTD1 and NTD2 are for neutron transmutation doping, CNS for the cold neutron source installation, and LH for the irradiation of large targets. The high resolution powder diffractometer (HRPD) became operational in 1998, followed by the four circle diffractometer (FCD) in 1999, the residual stress instrument (RSI) in 2000, and the small angle neutron spectrometer (SANS) in 2001, respectively. HRPD and SANS became the most popular instruments these days, attracting wide range of users from academia, institutes and industries. We have made a lot of efforts during the last 10 years to develop some key components such as

  15. Thermal neutron self-shielding correction factors for large sample instrumental neutron activation analysis using the MCNP code

    International Nuclear Information System (INIS)

    Tzika, F.; Stamatelatos, I.E.

    2004-01-01

    Thermal neutron self-shielding within large samples was studied using the Monte Carlo neutron transport code MCNP. The code enabled a three-dimensional modeling of the actual source and geometry configuration including reactor core, graphite pile and sample. Neutron flux self-shielding correction factors derived for a set of materials of interest for large sample neutron activation analysis are presented and evaluated. Simulations were experimentally verified by measurements performed using activation foils. The results of this study can be applied in order to determine neutron self-shielding factors of unknown samples from the thermal neutron fluxes measured at the surface of the sample

  16. Modelisation and distribution of neutron flux in radium-beryllium source (226Ra-Be)

    Science.gov (United States)

    Didi, Abdessamad; Dadouch, Ahmed; Jai, Otman

    2017-09-01

    Using the Monte Carlo N-Particle code (MCNP-6), to analyze the thermal, epithermal and fast neutron fluxes, of 3 millicuries of radium-beryllium, for determine the qualitative and quantitative of many materials, using method of neutron activation analysis. Radium-beryllium source of neutron is established to practical work and research in nuclear field. The main objective of this work was to enable us harness the profile flux of radium-beryllium irradiation, this theoretical study permits to discuss the design of the optimal irradiation and performance for increased the facility research and education of nuclear physics.

  17. Instrumental neutron activation determination of gold in mineral raw materials using a californium neutron source

    International Nuclear Information System (INIS)

    Shilo, N.A.; Ippolitov, E.G.; Ivanenko, V.V.; Kustov, B.N.; Zheleznov, V.V.; Aristov, G.N.; Kovalenko, V.V.; Kondrat'ev, N.B.

    1983-01-01

    A facility using a californium neutron source and a method for the neutron activation analysis of gold were developed. The sensitivity of the determination is 0.1 g/t. The causes of random and systematic errors have been studied. It is concluded that in prospection and evaluation of gold ore deposists, the traditional test tube analysis for gold may be replaced with the developed method. (author)

  18. Neutronic activation analysis of antique ceramics. Groups and differenciation

    International Nuclear Information System (INIS)

    Widemann, F.

    1975-01-01

    Different techniques for clay analysis in view of studying the origin of ceramics are exposed. The element abundance is measured by X-ray fluorescence analysis or by neutron activation analysis. Comparative tables of the results are established [fr

  19. Elemental analysis of combustion products by neutron activation

    International Nuclear Information System (INIS)

    Heft, R.E.; Koszykowski, R.F.

    1980-01-01

    This paper gives a brief description of the neutron activation analysis method, which is being used to determine the elemental profile of combustion products from coal-fired power plants, oil shale retorting, and underground coal gasification

  20. Instrumental Neutron Activation Analysis and Multivariate Statistics for Pottery Provenance

    Science.gov (United States)

    Glascock, M. D.; Neff, H.; Vaughn, K. J.

    2004-06-01

    The application of instrumental neutron activation analysis and multivariate statistics to archaeological studies of ceramics and clays is described. A small pottery data set from the Nasca culture in southern Peru is presented for illustration.

  1. Instrumental Neutron Activation Analysis and Multivariate Statistics for Pottery Provenance

    International Nuclear Information System (INIS)

    Glascock, M. D.; Neff, H.; Vaughn, K. J.

    2004-01-01

    The application of instrumental neutron activation analysis and multivariate statistics to archaeological studies of ceramics and clays is described. A small pottery data set from the Nasca culture in southern Peru is presented for illustration.

  2. Instrumental Neutron Activation Analysis and Multivariate Statistics for Pottery Provenance

    Energy Technology Data Exchange (ETDEWEB)

    Glascock, M. D.; Neff, H. [University of Missouri, Research Reactor Center (United States); Vaughn, K. J. [Pacific Lutheran University, Department of Anthropology (United States)

    2004-06-15

    The application of instrumental neutron activation analysis and multivariate statistics to archaeological studies of ceramics and clays is described. A small pottery data set from the Nasca culture in southern Peru is presented for illustration.

  3. Activation measurements for fast neutrons. Part E. Evaluation of fast neutron 63Ni transmission factors

    International Nuclear Information System (INIS)

    Egbert, Stephen D.

    2005-01-01

    The 63 Ni measurements for fast neutrons in copper samples are compared to the calculated free-in-air 63 Ni neutron activation given in Chapter 3 by use of transmission factors. Transmission factors were calculated to account for the modification of the fluence and activation at each sample's in situ location. For the purposes of this discussion, the transmission factor (TF) is defined as the ratio of the in situ sample activation divided by the untilted free-in-air (FIA) activation at a height of 1 m above ground at the same ground range. Examples of the application of TF's will be provided in this section. (author)

  4. Neutron activation analysis for certification of standard reference materials

    International Nuclear Information System (INIS)

    Capote Rodriguez, G.; Perez Zayas, G.; Hernandez Rivero, A.; Ribeiro Guevara, S.

    1996-01-01

    Neutron activation analysis is used extensively as one of the analytical techniques in the certification of standard reference materials. Characteristics of neutron activation analysis which make it valuable in this role are: accuracy multielemental capability to asses homogeneity, high sensitivity for many elements, and essentially non-destructive method. This paper report the concentrations of 30 elements (major, minor and trace elements) in four Cuban samples. The samples were irradiated in a thermal neutron flux of 10 12- 10 13 n.cm 2. s -1. The gamma ray spectra were measured by HPGe detectors and were analyzed using ACTAN program development in Center of Applied Studies for Nuclear Development

  5. Use of Germanium as comparator and integral monitor of neutron flux in activation analysis; Utilizacion del germanio como comparador y monitor integral de flujo neutronico en analisis por activacion

    Energy Technology Data Exchange (ETDEWEB)

    Furnari, Juan C.; Cohen, Isaac M. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Centro Atomico Ezeiza; Arribere, Maria A.; Kestelman, Abraham J. [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche

    1997-10-01

    The possibility of using germanium as monitor of the thermal and epithermal components of the neutron flux, and comparator in parametric activation analysis, is discussed. The advantages and drawbacks associated to the use of this element are commented on, and the comparison with zirconium, in terms of the determination relative error, is performed. The utilisation of germanium as integral flux monitor, including the fast component of the neutron spectrum, is also discussed. Data corresponding to measurements of k{sub 0} factor for the most relevant gamma transitions from Ge-75 and Be-77 are presented, as well as the results of the reference material analysis, employing germanium as flux monitor and comparator in a simultaneous way. (author). 8 refs., 3 figs., 2 tabs.

  6. Bulk hydrogen analysis, using neutrons. Final report of the second research co-ordination meeting

    International Nuclear Information System (INIS)

    1998-11-01

    The aims of the Second Co-ordination Meting (RCM) of the Coordinated Research Programme (CRP) were to report on and review progress against the work programme set at the beginning of the CRP and to discuss the work plans for the second half of the programme. In many cases hydrogen is required to be measured in a bulk medium rather than merely at a surface. For this reason neutrons are used due to their high penetrating power in dense material. In addition, the mass attenuation coefficient for neutrons in hydrogen is significantly larger than for all other elements, meaning that neutrons have a higher probability of interacting with hydrogen than with other elements in the sample matrix. Neutrons have been used in the following areas: Fast Neutron Transmission, Scattering and Activation Technique; Digital Neutron Imaging; Hydrogen Detection by Epithermal Neutrons; Microscopic Behaviour of Hydrogen in Bulk Materials

  7. Applicability of the activation analysis with prompt neutron in medicine

    International Nuclear Information System (INIS)

    Yaghubian-Malhami, R.

    1975-04-01

    The concentrations of boron and cadmium in the human body are of great importance in medicine. The author determined their concentration by prompt neutron activation analysis in aqueous solutions and in urine. The results show that this technique may be used in medical diagnosis. The author discusses the qualities and the applicability of delayed and prompt neutron activation analysis in biology and medicine. (C.R.)

  8. Neutron activation analysis: an emerging technique for conservation/preservation

    International Nuclear Information System (INIS)

    Sayre, E.V.

    1976-01-01

    The diverse applications of neutron activation in analysis, preservation, and documentation of art works and artifacts are described with illustrations for each application. The uses of this technique to solve problems of attribution and authentication, to reveal the inner structure and composition of art objects, and, in some instances to recreate details of the objects are described. A brief discussion of the theory and techniques of neutron activation analysis is also included

  9. Neutron activation and mass spectrometric measurement of /sup 129/I

    International Nuclear Information System (INIS)

    Strebin, R.S. Jr.; Brauer, F.P.; Kaye, J.H.; Rapids, M.S.; Stoffels, J.J.

    1987-11-01

    An integrated procedure has been developed for measurement of /sup 129/I by neutron activation analysis and mass spectrometry. An iodine isolation procedure previously used for neutron activation has been modified to provide separated iodine suitable for mass spectrometric measurement as well. Agreement between both methods has been achieved within error limits. The measurement limit by each method is about 10/sup 7/ atoms (2 fg) of /sup 129/I. 13 refs,. 4 figs., 1 tab

  10. Neutron activation analysis for noble metals in matte leach residues

    International Nuclear Information System (INIS)

    Hart, R.J.

    1978-01-01

    The development of the neutron activation analysis technique as a method for rapid and precise determinations of platinum group metals in matte leach residues depends on obtaining a method for effecting complete and homogeneous sample dilution. A simple method for solid dilution of metal samples is outlined in this study, which provided a basis for the accurate determination of all the noble metals by the Neutron Activation Analysis technique

  11. Diagnosis of mucoviscidosis by neutron activation analysis. Part 1

    International Nuclear Information System (INIS)

    Bellido, Luis F.; Bellido, Alfredo V.

    1997-02-01

    Symptoms pathology, incidence, and gravity of the inherent syndrome called mucoviscidosis, or cystic fibrosis are described in this Part I. The analytical methods used for its diagnosis, both the conventional chemical ones and by neutron activation analysis are also summarised. Finally, an analytical method to study the incidence of mucoviscidosis in Brazil is presented. This , essentially, consists in bromine determination, in fingernails, by resonance neutron activation analysis. (author)

  12. A neutron beam polarizer for study of parity violation in neutron-nucleus interactions

    International Nuclear Information System (INIS)

    Penttilae, S.I.; Bowman, J.D.; Frankle, C.M.; Seestrom, S.J.; Yen, Yi-Fen; Delheij, P.P.J.; Haase, D.G.; Postma, H.

    1994-01-01

    A dynamically-polarized proton target operating at 5 Tesla and 1 K has been built to, neutron beam for studies of parity violation in compound-nuclear resonances. Nearly 0.9 proton polarization was obtained in an electron-beam irradiated ammonia target. This was used to produce a neutron beam polarization of 0.7 at epithermal energies. The combination of the polarized proton target and the LANSCE spallation neutron source produces the most intense pulsed polarized epithermal neutron beam in the world. The neutron-beam polarizer is described and methods to determine neutron beam polarization are presented

  13. Thermal neutron imaging in an active interrogation environment

    International Nuclear Information System (INIS)

    Vanier, P.E.; Forman, L.; Norman, D.R.

    2009-01-01

    We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of excitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutronemitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

  14. Overview of Australian activities of fusion neutronics

    International Nuclear Information System (INIS)

    Zimin, S.; Dewar, R.L.

    1999-01-01

    The new status of the H-1NF heliac stellarator as a national facility and the signed international implementing agreement on collaboration in the development of the stellarator concept should together be a significant encouragement for further fusion research in Australia. In this report the future of fusion research in Australia is discussed with special attention being paid to the importance of stellarator power plant studies and in particular stellarator fusion neutronics. The main differences between tokamak and stellarator neutronics analyses are identified, namely the neutron wall loading, geometrical modelling and total heating in in-vessel reactor components including toroidal field (TF) coils. An approach to stellarator (TF) coils heating calculations is discussed. This approach is a modification of a previously reported method of total heating calculations in tokamak TF coils. Due to the more complicated nature of stellarator neutronics analyses, simplified approaches to fusion neutronics already developed for tokamaks are expected to be even more important and widely used for designing a conceptual stellarator power plant. (orig.)

  15. On-line neutron activation analyzers

    International Nuclear Information System (INIS)

    Flahaut, V.; Colmon, A.

    1999-01-01

    A neutronic analyser has been designed to determine the composition of the flow of raw materials entering a cement factory on the conveyor belt. This new system gives a reliable analysis of the whole cargo that outdates the sampling or the usual surface analysis based on fluorescence spectrometry. The accuracy is about 1%.The neutrons interact with the materials on an average depth of 25 cm and are absorbed by nuclei, these nuclei produce photons whose energy is characteristic of the chemical element itself. The composition can be deduced by measuring the number of photons emitted and their energy. The analysis is made on-line and can concern the search for about 10 compounds. In the case of cement the list of compounds is: SiO 2 , CaO, Al 2 O 3 , Fe 2 O 3 , MgO, Na 2 O, TiO 2 , S, Mn 2 O 3 , K 2 O, and H 2 O. The neutron generator involves a deuterium ion source whose deuterium ions are accelerated by means of an electrical field and impinge on a tritiated target, the nuclear reactions between deuterium and tritium produce 14 MeV neutrons. This neutron analysing technique can be adapted to any need of on-line composition determination. (A.C.)

  16. System to detect nuclear materials by active neutron method

    International Nuclear Information System (INIS)

    Koroev, M.; Korolev, Yu.; Lopatin, Yu.; Filonov, V.

    1999-01-01

    The report presents the results of the development of the system to detect nuclear materials by active neutron method measuring delayed neutrons. As the neutron source the neutron generator was used. The neutron generator was controlled by the system. The detectors were developed on the base of the helium-3 counters. Each detector consist of 6 counters. Using a number of such detectors it is possible to verify materials stored in different geometry. There is an spectrometric scintillator detector in the system which gives an additional functional ability to the system. The system could be used to estimate the nuclear materials in waste, to detect the unauthorized transfer of the nuclear materials, to estimate the material in tubes [ru

  17. The investigation of fast neutron Threshold Activation Detectors (TAD)

    International Nuclear Information System (INIS)

    Gozani, T; King, M J; Stevenson, J

    2012-01-01

    The detection of fast neutrons is usually done by liquid hydrogenous organic scintillators, where the separation between the ever present gamma rays and neutrons is achieved by the pulse shape discrimination (PSD). In many practical situation the detection of fast neutrons has to be carried out while the intense source (be it neutrons, gamma rays or x-rays) that creates these neutrons, for example by the fission process, is present. This source, or ''flash'', usually blinds the neutron detectors and temporarily incapacitates them. By the time the detectors recover the prompt neutron signature does not exist. Thus to overcome the blinding background, one needs to search for processes whereby the desired signature, such as fission neutrons could in some way be measured long after the fission occurred and when the neutron detector is fully recovered from the overload. A new approach was proposed and demonstrated a good sensitivity for the detection of fast neutrons in adverse overload situations where normally it could not be done. A temporal separation of the fission event from the prompt neutrons detection is achieved via the activation process. The main idea, called Threshold Activation Detection (or detector)-TAD, is to find appropriate substances that can be selectively activated by the fission neutrons and not by the source radiation, and then measure the radioactively decaying activation products (typically beta and γ-rays) well after the source pulse has ended. The activation material should possess certain properties: a suitable half-life; an energy threshold below which the numerous source neutrons will not activate it (e.g. about 3 MeV); easily detectable activation products and has a usable cross section for the selected reaction. Ideally the substance would be part of the scintillator. There are several good candidates for TAD. The first one we have selected is based on fluorine. One of the major advantages of this element is the fact that it is a major

  18. The investigation of fast neutron Threshold Activation Detectors (TAD)

    Science.gov (United States)

    Gozani, T.; King, M. J.; Stevenson, J.

    2012-02-01

    The detection of fast neutrons is usually done by liquid hydrogenous organic scintillators, where the separation between the ever present gamma rays and neutrons is achieved by the pulse shape discrimination (PSD). In many practical situation the detection of fast neutrons has to be carried out while the intense source (be it neutrons, gamma rays or x-rays) that creates these neutrons, for example by the fission process, is present. This source, or ``flash'', usually blinds the neutron detectors and temporarily incapacitates them. By the time the detectors recover the prompt neutron signature does not exist. Thus to overcome the blinding background, one needs to search for processes whereby the desired signature, such as fission neutrons could in some way be measured long after the fission occurred and when the neutron detector is fully recovered from the overload. A new approach was proposed and demonstrated a good sensitivity for the detection of fast neutrons in adverse overload situations where normally it could not be done. A temporal separation of the fission event from the prompt neutrons detection is achieved via the activation process. The main idea, called Threshold Activation Detection (or detector)-TAD, is to find appropriate substances that can be selectively activated by the fission neutrons and not by the source radiation, and then measure the radioactively decaying activation products (typically beta and γ-rays) well after the source pulse has ended. The activation material should possess certain properties: a suitable half-life; an energy threshold below which the numerous source neutrons will not activate it (e.g. about 3 MeV); easily detectable activation products and has a usable cross section for the selected reaction. Ideally the substance would be part of the scintillator. There are several good candidates for TAD. The first one we have selected is based on fluorine. One of the major advantages of this element is the fact that it is a major

  19. Uses of reactor neutrons for studying the microcomposition of materials

    International Nuclear Information System (INIS)

    Jervis, R.E.

    1993-01-01

    Reactor neutrons constitute excellents 'probes' for exploring and measuring a wide range both of minor and trace constituents in solids and liquids with high sensitivity because of their transparency in materials. Nondestructive neutron prompt-gamma analysis (PGA) utilizing either cold or thermal neutrons, such as at JRR-3M, is compared and contrasted to the more common (delayed) instrumental neutron activation analysis (INAA) and epithermal NAA. Clearly PGA offers high sensitivity for selected elements: B, H, Cd and REE's in suitable matrices, and is therefore, complementary to INAA which is not as useful for them, or for Ni, Sn, Fe, C or N. Recent INAA applications in our laboratory that demonstrate some of the uniqueness of neutron methods include use of epithermal neutrons for small biological specimens to measure Cd, K, As, Zn and, multielemental INAA for environmental pollution studies. The latter involves large data sets of multielemental concentrations which are subjected to statistical multivariant factor analysis to reveal unknown or unsuspected quantitative relationships among groups of trace constituents. These patterns, or 'factors' are shown to be uniquely related to pollution sources and can be utilized to compute the relative source contributions at a given receptor site. (author)

  20. The neutron porosity tool

    International Nuclear Information System (INIS)

    Oelgaard, P.L.

    1988-01-01

    The report contains a review of available information on neutron porosity tools with the emphasis on dual thermal-neutron-detector porosity tools and epithermal-neutron-detector porosity tools. The general principle of such tools is discussed and theoretical models are very briefly reviewed. Available data on tool designs are summarized with special regard to the source-detector distance. Tool operational data, porosity determination and correction of measurements are briefly discussed. (author) 15 refs

  1. Neutron threshold activation detectors (TAD) for the detection of fissions

    Science.gov (United States)

    Gozani, Tsahi; Stevenson, John; King, Michael J.

    2011-10-01

    Prompt fission neutrons are one of the strongest signatures of the fission process. Depending on the fission inducing radiation, their average number ranges from 2.5 to 4 neutrons per fission. They are more energetic and abundant, by about 2 orders of magnitude, than the delayed neutrons (≈3 vs. ≈0.01) that are commonly used as indicators for the presence of fissionable materials. The detection of fission prompt neutrons, however, has to be done in the presence of extremely intense probing radiation that stimulated them. During irradiation, the fission stimulation radiation, X-rays or neutrons, overwhelms the neutron detectors and temporarily incapacitate them. Consequently, by the time the detectors recover from the source radiation, fission prompt neutrons are no longer emitted. In order to measure the prompt fission signatures under these circumstances, special measures are usually taken with the detectors such as heavy shielding with collimation, use of inefficient geometries, high pulse height bias and gamma-neutron separation via pulse-shape discrimination with an appropriate organic scintillator. These attempts to shield the detector from the flash of radiation result in a major loss of sensitivity. It can lead to a complete inability to detect the fission prompt neutrons. In order to overcome the blinding induced background from the source radiation, the detection of prompt fission neutrons needs to occur long after the fission event and after the detector has fully recovered from the source overload. A new approach to achieve this is to detect the delayed activation induced by the fission neutrons. The approach demonstrates a good sensitivity in adverse overload situations (gamma and neutron "flash") where fission prompt neutrons could normally not be detected. The new approach achieves the required temporal separation between the detection of prompt neutrons and the detector overload by the neutron activation of the detector material. The technique

  2. Neutron threshold activation detectors (TAD) for the detection of fissions

    International Nuclear Information System (INIS)

    Gozani, Tsahi; Stevenson, John; King, Michael J.

    2011-01-01

    Prompt fission neutrons are one of the strongest signatures of the fission process. Depending on the fission inducing radiation, their average number ranges from 2.5 to 4 neutrons per fission. They are more energetic and abundant, by about 2 orders of magnitude, than the delayed neutrons (∼3 vs. ∼0.01) that are commonly used as indicators for the presence of fissionable materials. The detection of fission prompt neutrons, however, has to be done in the presence of extremely intense probing radiation that stimulated them. During irradiation, the fission stimulation radiation, X-rays or neutrons, overwhelms the neutron detectors and temporarily incapacitate them. Consequently, by the time the detectors recover from the source radiation, fission prompt neutrons are no longer emitted. In order to measure the prompt fission signatures under these circumstances, special measures are usually taken with the detectors such as heavy shielding with collimation, use of inefficient geometries, high pulse height bias and gamma-neutron separation via pulse-shape discrimination with an appropriate organic scintillator. These attempts to shield the detector from the flash of radiation result in a major loss of sensitivity. It can lead to a complete inability to detect the fission prompt neutrons. In order to overcome the blinding induced background from the source radiation, the detection of prompt fission neutrons needs to occur long after the fission event and after the detector has fully recovered from the source overload. A new approach to achieve this is to detect the delayed activation induced by the fission neutrons. The approach demonstrates a good sensitivity in adverse overload situations (gamma and neutron 'flash') where fission prompt neutrons could normally not be detected. The new approach achieves the required temporal separation between the detection of prompt neutrons and the detector overload by the neutron activation of the detector material. The technique

  3. Neutron threshold activation detectors (TAD) for the detection of fissions

    Energy Technology Data Exchange (ETDEWEB)

    Gozani, Tsahi, E-mail: tgozani@rapiscansystems.com [Rapiscan Laboratories, Inc., 520 Almanor Ave., Sunnyvale, CA 94085 (United States); Stevenson, John; King, Michael J. [Rapiscan Laboratories, Inc., 520 Almanor Ave., Sunnyvale, CA 94085 (United States)

    2011-10-01

    Prompt fission neutrons are one of the strongest signatures of the fission process. Depending on the fission inducing radiation, their average number ranges from 2.5 to 4 neutrons per fission. They are more energetic and abundant, by about 2 orders of magnitude, than the delayed neutrons ({approx}3 vs. {approx}0.01) that are commonly used as indicators for the presence of fissionable materials. The detection of fission prompt neutrons, however, has to be done in the presence of extremely intense probing radiation that stimulated them. During irradiation, the fission stimulation radiation, X-rays or neutrons, overwhelms the neutron detectors and temporarily incapacitate them. Consequently, by the time the detectors recover from the source radiation, fission prompt neutrons are no longer emitted. In order to measure the prompt fission signatures under these circumstances, special measures are usually taken with the detectors such as heavy shielding with collimation, use of inefficient geometries, high pulse height bias and gamma-neutron separation via pulse-shape discrimination with an appropriate organic scintillator. These attempts to shield the detector from the flash of radiation result in a major loss of sensitivity. It can lead to a complete inability to detect the fission prompt neutrons. In order to overcome the blinding induced background from the source radiation, the detection of prompt fission neutrons needs to occur long after the fission event and after the detector has fully recovered from the source overload. A new approach to achieve this is to detect the delayed activation induced by the fission neutrons. The approach demonstrates a good sensitivity in adverse overload situations (gamma and neutron 'flash') where fission prompt neutrons could normally not be detected. The new approach achieves the required temporal separation between the detection of prompt neutrons and the detector overload by the neutron activation of the detector

  4. Measurements of DT and DD neutron yields by neutron activation on TFTR

    International Nuclear Information System (INIS)

    Barnes, C.W.; Larson, A.R.; LeMunyan, G.

    1994-01-01

    A variety of elemental foils have been activated by neutron fluence from TFTR under conditions with the DT neutron yield per shot ranging from 10 12 to over 10 18 , and with the DT/(DD+DT) neutron ratio varying from 0.5% (from triton burnup) to unity. Linear response over this large dynamic range is obtained by reducing the mass of the foils and increasing the cooling time, all while accepting greatly improved counting statistics. Effects on background gamma-ray lines from foil-capsule-material contaminants. and the resulting lower limits on activation foil mass, have been determined. DT neutron yields from dosimetry standard reactions on aluminum, chromium, iron, nickel, zirconium, and indium are in agreement within the ±9% (one-sigma,) accuracy of the measurements: also agreeing are yields from silicon foils using the ACTL library cross-section. While the ENDF/B-V library has too low a cross-section. Preliminary results from a variety of other threshold reactions are presented. Use of the 115 In(n,n) 115m In reaction (0.42 times as sensitive to DT neutrons as DD neutrons) in conjunction with pure-DT reactions allows a determination of the DT/(DD+DT) ratio in trace tritium or low-power tritium beam experiments

  5. Measurements of DT and DD neutron yields by neutron activation on TFTR

    International Nuclear Information System (INIS)

    Barnes, C.W.; Larson, A.R.; LeMunyan, G.

    1995-03-01

    A variety of elemental foils have been activated by neutron fluence from TFTR under conditions with the DT neutron yield per shot ranging from 10 12 to over 10 18 , and with the DT/(DD+DT) neutron ratio varying from 0.5% (from triton burnup) to unity. Linear response over this large dynamic range is obtained by reducing the mass of the foils and increasing the cooling time, all while accepting greatly improved counting statistics. Effects on background gamma-ray lines from foil-capsule-material contaminants, and the resulting lower limits on activation foil mass, have been determined. DT neutron yields from dosimetry standard reactions on aluminum, chromium, iron, nickel, zirconium, and indium are in agreement within the ±9% (one-sigma) accuracy of the measurements; also agreeing are yields from silicon foils using the ACTL library cross-section, while the ENDF/B-V library has too low a cross-section. Preliminary results from a variety of other threshold reactions are presented. Use of the 115 In(n.n') 115m In reaction (0.42 times as sensitive to DT neutrons as DD neutrons) in conjunction with pure-DT reactions allows a determination of the DT/(DD+DT) ratio in trace tritium or low-power tritium beam experiments

  6. Characterization of the neutron flow for the implementation of an experimental analysis installation for rapid gamma activation in the Argentine Research Reactor RA-6

    International Nuclear Information System (INIS)

    Henriquez, C.; Gennuso, G.

    2000-01-01

    This is the final work to obtain a Diploma on Specialization in Application of Nuclear Technological Energy, carried out at the Research Reactor RA-6, from March to December 1999. Different work has been realized on the Tangential Tube N of the 500 KW Argentine RA-6 research reactor, in order to add a new technique to the present existing analytical methods. This Prompt Gamma Neutron Activation Analysis technique (PGNAA) requires a beam of collimated thermal neutrons, a lowest possible gamma radiation, and a thermal component of the biggest possible cadmium rate. It also must have a high resolution detection system for the measurement of the gamma radiation emitted after the capture of the neutron produced in the study sample. Continuing with the facility's technical requirements, a collimator was installed inside the N passing tube, in order to concentrate the neutrons coming from the nuclear core and also to compensate possible losses during the path. This collimator is 440mm long and 200 mm in diameter and consists of lead and steel cylinders with different size holes on the inside, so that it can deliver a 50 mm diameter beam of thermal collimated neutrons. Two 100 mm thick bismuth filters are inside the passing tube, to reduce the gamma component inside de beam, coming from the reactor core. This work aims to the characterization of the thermal and epithermal component of the neutron beam in the collimator and at the exit of it , and also to prove experimentally that the collimator achieves the technical specifications for which it was designed and built, specifically by verifying its functioning (degree of convergence of the beam obtained). On the other hand, it is necessary to learn about the PGNAA technique in order to define the technical requirements for its adequate operation. (author)

  7. In vivo neutron activation facility at Brookhaven National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Ma, R.; Yasumura, Seiichi; Dilmanian, F.A.

    1997-11-01

    Seven important body elements, C, N, Ca, P, K, Na, and Cl, can be measured with great precision and accuracy in the in vivo neutron activation facilities at Brookhaven National Laboratory. The facilities include the delayed-gamma neutron activation, the prompt-gamma neutron activation, and the inelastic neutron scattering systems. In conjunction with measurements of total body water by the tritiated-water dilution method several body compartments can be defined from the contents of these elements, also with high precision. In particular, body fat mass is derived from total body carbon together with total body calcium and nitrogen; body protein mass is derived from total body nitrogen; extracellular fluid volume is derived from total body sodium and chlorine; lean body mass and body cell mass are derived from total body potassium; and, skeletal mass is derived from total body calcium. Thus, we suggest that neutron activation analysis may be valuable for calibrating some of the instruments routinely used in clinical studies of body composition. The instruments that would benefit from absolute calibration against neutron activation analysis are bioelectric impedance analysis, infrared interactance, transmission ultrasound, and dual energy x-ray/photon absorptiometry.

  8. A study on aluminum determination in environmental samples by Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Noyori, Amanda

    2017-01-01

    Aluminum determinations are of great interest since this element is toxic to humans and it is widely distributed in the environment. Besides, the determinations of this element by conventional analytical methods present difficulties due to sample contamination during the analyses. Neutron activation analysis (NAA) for Al determination presents advantages of fast analyses and of high sensitivity. However, NAA of Al does present problems of P and Si nuclear reaction interferences. Aluminum is determined by measuring 28 Al, formed in the reaction 27 Al (n, γ) 28 Al, the same radioisotope formed in reactions 31 P (n, α) 28 Al and 28 Si (n, p) 28 Al. The purpose of this study was to determine Al in environmental samples by NAA correcting these interferences using correction factors, and determining P and Si concentrations in the samples. In this study, certified reference materials and biomonitor samples (tree barks and lichen) were analyzed. Experimental procedure consisted of irradiating an aliquot of the sample at the IEA-R1 nuclear research reactor together with Al standard, followed by gamma ray spectrometry. Phosphorus was determined by measuring beta radiation of 32 P using a Geiger-Müller counter. Silicon was determined by epithermal neutron activation analysis and measuring 29 Al formed in the reaction 29 Si (n, p) 29 Al. Results obtained in the determination of Al, P and Si in the certified reference materials showed good precision and accuracy with |Z-score| ≤ 2. Aluminum results in the biomonitor samples varied from to 253 to 15783 μg g -1 . In the case of P its concentrations varied from 283 to 1946 μg g -1 . Silicon determinations in biomonitors varied from 0.11 to 7.8 %. The interference contribution rates in the analyses of the biomonitor samples were of the order of 2.0 % and this contribution depends on the relation between concentrations of interfering elements and of Al in the sample. Detection limit values of Al in the biomonitor analyses

  9. Beryllium neutron activation detector for pulsed DD fusion sources

    International Nuclear Information System (INIS)

    Talebitaher, A.; Springham, S.V.; Rawat, R.S.; Lee, P.

    2011-01-01

    A compact fast neutron detector based on beryllium activation has been developed to perform accurate neutron fluence measurements on pulsed DD fusion sources. It is especially well suited to moderate repetition-rate ( 9 Be(n,α) 6 He cross-section, energy calibration of the proportional counters, and numerical simulations of neutron interactions and beta-particle paths using MCNP5. The response function R(E n ) is determined over the neutron energy range 2-4 MeV. The count rate capability of the detector has been studied and the corrections required for high neutron fluence measurements are discussed. For pulsed DD neutron fluencies >3×10 4 cm -2 , the statistical uncertainty in the fluence measurement is better than 1%. A small plasma focus device has been employed as a pulsed neutron source to test two of these new detectors, and their responses are found to be practically identical. Also the level of interfering activation is found to be sufficiently low as to be negligible.

  10. Research and development activities of a neutron generator facility

    International Nuclear Information System (INIS)

    Darsono Sudjatmoko; Pramudita Anggraita; Sukarman Aminjoyo

    2000-01-01

    The neutron generator facility at YNRC is used for elemental analysis, nuclear data measurement and education. In nuclear data measurement the focus is on re-evaluating the existing scattered nuclear activation cross-section to obtain systematic data for nuclear reactions such as (n,p), (n,α), and (n,2n). In elemental analysis it is used for analyzing the Nitrogen (N), Phosphor (P) and Potassium (K) contents in chemical and natural fertilizers (compost), protein in rice, soybean, and corn and pollution level in rivers. The neutron generator is also used for education and training of BATAN staff and university students. The facility can also produce neutron generator components. (author)

  11. Prompt gamma cold neutron activation analysis applied to biological materials

    International Nuclear Information System (INIS)

    Rossbach, M.; Hiep, N.T.

    1992-01-01

    Cold neutrons at the external neutron guide laboratory (ELLA) of the KFA Juelich are used to demonstrate their profitable application for multielement characterization of biological materials. The set-up and experimental conditions of the Prompt Gamma Cold Neutron Activation Analysis (PGCNAA) device is described in detail. Results for C, H, N, S, K, B, and Cd using synthetic standards and the 'ratio' technique for calculation are reported for several reference materials and prove the method to be reliable and complementary with respect to the elements being determined by INAA. (orig.)

  12. Certification of standard reference materials employing neutron activation analysis

    International Nuclear Information System (INIS)

    Capote Rodriguez, G.; Hernandez Rivero, A.; Molina Insfran, J.; Ribeiro Guevara, S.; Santana Encinosa, C.; Perez Zayas, G.

    1997-01-01

    Neutron activation analysis (Naa) is used extensively as one of the analytical techniques in the certification of standard reference materials (Srm). Characteristics of Naa which make it valuable in this role are: accuracy; multielemental capability; ability to assess homogeneity; high sensitivity for many elements, and essentially non-destructive method. This paper reports the concentrations of thirty elements (major, minor and trace elements) in four Cuban Srm's. The samples were irradiated in a thermal neutron flux of 10 12 -10 13 neutrons.cm -2 .s -1 . The gamma-ray spectra were measured by HPGe detectors and were analysed using ACTAN program, developed in CEADEN. (author) [es

  13. Activation method for measuring the neutron spectra parameters. Computer software

    International Nuclear Information System (INIS)

    Efimov, B.V.; Ionov, V.S.; Konyaev, S.I.; Marin, S.V.

    2005-01-01

    The description of mathematical statement of a task for definition the spectral characteristics of neutron fields with use developed in RRC KI unified activation detectors (UKD) is resulted. The method of processing of results offered by authors activation measurements and calculation of the parameters used for an estimation of the neutron spectra characteristics is discussed. Features of processing of the experimental data received at measurements of activation with using UKD are considered. Activation detectors UKD contain a little bit specially the picked up isotopes giving at irradiation peaks scale of activity in the common spectrum scale of activity. Computing processing of results of the measurements is applied on definition of spectrum parameters for nuclear reactor installations with thermal and close to such power spectrum of neutrons. The example of the data processing, the measurements received at carrying out at RRC KI research reactor F-1 is resulted [ru

  14. Elemental analysis of fertilizer by fast neutron activation

    International Nuclear Information System (INIS)

    Bodart, F.; Deconninck, G.

    1977-01-01

    A simple and accurate technique has been developed to analyse commercial fertilizers for phosphorus, potassium, chlorine, magnesium and silicon. The method is based on fast-neutron activation using a neutron flux of 2x10 11 neutrons/second. The optimum analytical conditions are tabulated. After irradiation, the sample is measured on a conventional counting system including a Ge(Li) detector (10% efficiency and 2 keV resolution for 60 Co) and a multichannel analyser. Monitor foils radioactivity are measured separately at the same time with a 2''x2''NaI detector coupled with a single channel analyser and a scaler. Fast neutron activation has proved to be a fast, simple, reliable and low cost analytical technique for the determination of phosphorus, silicon, potassium, magnesium and chlorine in fertilizers. Not less than five phosphorus determinations are possible in one hour, while two potassium, magnesium and chlorine determinations are made at the same time. (T.G.)

  15. Neutron activation analysis of wheat samples

    International Nuclear Information System (INIS)

    Galinha, C.; Anawar, H.M.; Freitas, M.C.; Pacheco, A.M.G.; Almeida-Silva, M.; Coutinho, J.; Macas, B.; Almeida, A.S.

    2011-01-01

    The deficiency of essential micronutrients and excess of toxic metals in cereals, an important food items for human nutrition, can cause public health risk. Therefore, before their consumption and adoption of soil supplementation, concentrations of essential micronutrients and metals in cereals should be monitored. This study collected soil and two varieties of wheat samples-Triticum aestivum L. (Jordao/bread wheat), and Triticum durum L. (Marialva/durum wheat) from Elvas area, Portugal and analyzed concentrations of As, Cr, Co, Fe, K, Na, Rb and Zn using Instrumental Neutron Activation Analysis (INAA) to focus on the risk of adverse public health issues. The low variability and moderate concentrations of metals in soils indicated a lower significant effect of environmental input on metal concentrations in agricultural soils. The Cr and Fe concentrations in soils that ranged from 93-117 and 26,400-31,300 mg/kg, respectively, were relatively high, but Zn concentration was very low (below detection limit Fe>Na>Zn>Cr>Rb>As>Co. Concentrations of As, Co and Cr in root, straw and spike of both varieties were higher than the permissible limits with exception of a few samples. The concentrations of Zn in root, straw and spike were relatively low (4-30 mg/kg) indicating the deficiency of an essential micronutrient Zn in wheat cultivated in Portugal. The elemental transfer from soil to plant decreases with increasing growth of the plant. The concentrations of various metals in different parts of wheat followed the order: Root>Straw>Spike. A few root, straw and spike samples showed enrichment of metals, but the majority of the samples showed no enrichment. Potassium is enriched in all samples of root, straw and spike for both varieties of wheat. Relatively to the seed used for cultivation, Jordao presented higher transfer coefficients than Marialva, in particular for Co, Fe, and Na. The Jordao and Marialva cultivars accumulated not statistically significant different

  16. Neutron activation analysis of wheat samples

    Energy Technology Data Exchange (ETDEWEB)

    Galinha, C. [CERENA-IST, Technical University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Instituto Tecnoclogico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Anawar, H.M. [Instituto Tecnoclogico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Freitas, M.C., E-mail: cfreitas@itn.pt [Instituto Tecnoclogico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Pacheco, A.M.G. [CERENA-IST, Technical University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Almeida-Silva, M. [Instituto Tecnoclogico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Coutinho, J.; Macas, B.; Almeida, A.S. [INRB/INIA-Elvas, National Institute of Biological Resources, Est. Gil Vaz, 7350-228 Elvas (Portugal)

    2011-11-15

    The deficiency of essential micronutrients and excess of toxic metals in cereals, an important food items for human nutrition, can cause public health risk. Therefore, before their consumption and adoption of soil supplementation, concentrations of essential micronutrients and metals in cereals should be monitored. This study collected soil and two varieties of wheat samples-Triticum aestivum L. (Jordao/bread wheat), and Triticum durum L. (Marialva/durum wheat) from Elvas area, Portugal and analyzed concentrations of As, Cr, Co, Fe, K, Na, Rb and Zn using Instrumental Neutron Activation Analysis (INAA) to focus on the risk of adverse public health issues. The low variability and moderate concentrations of metals in soils indicated a lower significant effect of environmental input on metal concentrations in agricultural soils. The Cr and Fe concentrations in soils that ranged from 93-117 and 26,400-31,300 mg/kg, respectively, were relatively high, but Zn concentration was very low (below detection limit <22 mg/kg) indicating that soils should be supplemented with Zn during cultivation. The concentrations of metals in roots and straw of both varieties of wheat decreased in the order of K>Fe>Na>Zn>Cr>Rb>As>Co. Concentrations of As, Co and Cr in root, straw and spike of both varieties were higher than the permissible limits with exception of a few samples. The concentrations of Zn in root, straw and spike were relatively low (4-30 mg/kg) indicating the deficiency of an essential micronutrient Zn in wheat cultivated in Portugal. The elemental transfer from soil to plant decreases with increasing growth of the plant. The concentrations of various metals in different parts of wheat followed the order: Root>Straw>Spike. A few root, straw and spike samples showed enrichment of metals, but the majority of the samples showed no enrichment. Potassium is enriched in all samples of root, straw and spike for both varieties of wheat. Relatively to the seed used for cultivation

  17. Evaluation of new pharmaceuticals using in vivo neutron inelastic scattering and neutron activation analysis

    International Nuclear Information System (INIS)

    Kehayias, J.J.

    2000-01-01

    Nutritional status of patients can be evaluated by monitoring changes in body composition, including depletion of protein and muscle, adipose tissue distribution and changes in hydration status, bone or cell mass. Fast neutron activation (for N and P) and neutron inelastic scattering (for C and O) are used to assess in vivo elements characteristic of specific body compartments. The fast neutrons are produced with a sealed deuterium-tritium (D-T) neutron generator. This method provides the most direct assessment of body composition. Non-bone phosphorus for muscle is measured by the 31 P(n,α) 28 Al reaction, and nitrogen for protein via the (n,2n) fast neutron reaction. Inelastic neutron scattering is used for the measurement of total body carbon and oxygen. Carbon is used to derive body fat, after subtracting carbon contributions due to protein, bone and glycogen. Carbon-to-oxygen (C/O) ratio is used to measure distribution of fat and lean tissue in the body and to monitor small changes of lean mass and its quality. In addition to evaluating the efficacy of new treatments, the system is used to study the mechanisms of lean tissue depletion with aging and to investigate methods for preserving function and quality of life in the elderly. (author)

  18. Fast neutron activating detectors for pulsed flow measurements

    International Nuclear Information System (INIS)

    Dyatlov, V.D.; Kunaev, G.T.; Popytaev, A.N.; Cheremukhov, B.V.

    1979-01-01

    The requirements to the activation detectors of the pulsed flows of the fast neutrons are considered; the criteria of optimum measurement time, geometrical moderator sizes and radioactive detector element properties have been obtained. On their analysis parameter selection has been carried out. The neutron detector to register the short pulses has been designed and calibrated. The ways of further increase of sensitivity and efficiency of such detectors are discussed

  19. Transportable, Low-Dose Active Fast-Neutron Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mihalczo, John T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wright, Michael C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McConchie, Seth M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Archer, Daniel E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Palles, Blake A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    This document contains a description of the method of transportable, low-dose active fast-neutron imaging as developed by ORNL. The discussion begins with the technique and instrumentation and continues with the image reconstruction and analysis. The analysis discussion includes an example of how a gap smaller than the neutron production spot size and detector size can be detected and characterized depending upon the measurement time.

  20. Survey of Neutron Generators for Active Interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Moss, Calvin Elroy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Myers, William L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sundby, Gary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chichester, David L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Johnson, James P. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-05-02

    Some of these commercially available generators meet all of the requirements in Table 1, but there are other concerns. Most generators containing SF6 will be required to have the SF6 gas removed for shipping because of DOT regulations. However, Thermo Fisher has a DOT exemption. The P211 and B211 from Thermo Fisher meet the requirements listed in Table 1, but they are old designs and are no longer offered for sale. Also, they require 15 minutes or more of warmup before neutron output is available, and they lack a modern digital control. The nGen-300C from Starfire Industries is interesting because it is a portable system, but it uses the DD reaction for 2.5 MeV neutrons, which are not as penetrating as the 14 MeV neutrons from the DT reaction. The MP 320 from Thermo Fisher is another portable system, but the minimum pulse rate is 250 Hz, which is too fast for measurement of delayed neutrons and re-interrogation by delayed neutrons between pulses. The Genie 16 from Sodern (from France) probably meets the requirements, but the required power is probably too high for battery operation. The generators from Russia and China may be difficult to purchase, and service may not be available. The power required by some of these generators is low enough that batteries can be used. The portable units, nGen-300C and the MP320, could easily be operated with batteries. Other generators with low power requirements, as specified in the above vendors list, could possibly be operated with reason size batteries. The batteries do not need to be internal to the generator, but can be in a separate package. The availability of high capacity lithium batteries with sophisticated safety circuits makes battery operation more possible now than when lead acid batteries were used. The best path forward probably requires working with vendors of the existing systems. If Starfire Industries could be persuaded to put tritium in their nGen-300C generator, possibly in collaboration with a national