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Sample records for californium

  1. Californium Electrodepositions at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Boll, Rose Ann [ORNL

    2015-01-01

    Electrodepositions of californium isotopes were successfully performed at Oak Ridge National Laboratory (ORNL) during the past year involving two different types of deposition solutions, ammonium acetate (NH4C2H3O2) and isobutanol ((CH3)2CHCH2OH). A californium product that was decay enriched in 251Cf was recovered for use in super-heavy element (SHE) research. This neutron-rich isotope, 251Cf, provides target material for SHE research for the potential discovery of heavier isotopes of Z=118. The californium material was recovered from aged 252Cf neutron sources in storage at ORNL. These sources have decayed for over 30 years, thus providing material with a very high 251Cf-to-252Cf ratio. After the source capsules were opened, the californium was purified and then electrodeposited using the isobutanol method onto thin titanium foils for use in an accelerator at the Joint Institute for Nuclear Research in Dubna, Russia. Another deposition method, ammonium acetate, was used to produce a deposition containing 1.7 0.1 Ci of 252Cf onto a stainless steel substrate. This was the largest single electrodeposition of 252Cf ever prepared. The 252Cf material was initially purified using traditional ion exchange media, such as AG50-AHIB and AG50-HCl, and further purified using a TEVA-NH4SCN system to remove any lanthanides, resulting in the recovery of 3.6 0.1 mg of purified 252Cf. The ammonium acetate deposition was run with a current of 1.0 amp, resulting in a 91.5% deposition yield. Purification and handling of the highly radioactive californium material created additional challenges in the production of these sources.

  2. Historical Review of Californium-252 Discovery and Development

    Science.gov (United States)

    Stoddard, D. H.

    1985-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-10-03

    The radioisotope {sup 252}Cf is routinely encapsulated into compact, portable, intense neutron sources with a 2.6-year half-life. A source the size of a person's little finger can emit up to 10{sup 11} neutrons/s. Californium-252 is used commercially as a reliable, cost-effective neutron source for prompt gamma neutron activation analysis (PGNAA) of coal, cement, and minerals, as well as for detection and identification of explosives, laud mines, and unexploded military ordnance. Other uses are neutron radiography, nuclear waste assays, reactor start-up sources, calibration standards, and cancer therapy. The inherent safety of source encapsulations is demonstrated by 30 years of experience and by U.S. Bureau of Mines tests of source survivability during explosions. The production and distribution center for the U. S Department of Energy (DOE) Californium Program is the Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL). DOE sells The radioisotope {sup 252}Cf is routinely encapsulated into compact, portable, intense neutron sources with a 2.6- year half-life. A source the size of a person's little finger can emit up to 10 neutrons/s. Californium-252 is used commercially as a reliable, cost-effective neutron source for prompt gamma neutron activation analysis (PGNAA) of coal, cement, and minerals, as well as for detection and identification of explosives, laud mines, and unexploded military ordnance. Other uses are neutron radiography, nuclear waste assays, reactor start-up sources, calibration standards, and cancer therapy. The inherent safety of source encapsulations is demonstrated by 30 years of experience and by U.S. Bureau of Mines tests of source survivability during explosions. The production and distribution center for the U. S Department of Energy (DOE) Californium Program is the Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory(ORNL). DOE sells {sup 252}Cf to commercial

  4. Teratogenic effect of Californium-252 irradiation in rats

    Energy Technology Data Exchange (ETDEWEB)

    Satow, Yukio; Lee, Juing-Yi; Hori, Hiroshi; Okuda, Hiroe; Tsuchimoto, Shigeo; Sawada, Shozo; Yokoro, Kenjiro (Hiroshima Univ. (Japan). Research Inst. for Nuclear Medicine and Biology)

    1989-06-01

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

  5. Apparatus for the measurement of total body nitrogen using prompt neutron activation analysis with californium-252.

    Science.gov (United States)

    Mackie, A; Hannan, W J; Smith, M A; Tothill, P

    1988-01-01

    Details of clinical apparatus designed for the measurement of total body nitrogen (as an indicator of body protein), suitable for the critically ill, intensive-care patient are presented. Californium-252 radio-isotopic neutron sources are used, enabling a nitrogen measurement by prompt neutron activation analysis to be made in 40 min with a precision of +/- 3.2% for a whole body dose equivalent of 0.145 mSv. The advantages of Californium-252 over alternative neutron sources are discussed. A comparison between two irradiation/detection geometries is made, leading to an explanation of the geometry adopted for the apparatus. The choice of construction and shielding materials to reduce the count rate at the detectors and consequently to reduce the pile-up contribution to the nitrogen background is discussed. Salient features of the gamma ray spectroscopy system to reduce spectral distortion from pulse pile-up are presented.

  6. Spontaneous Partitioning of Californium from Curium: Curious Cases from the Crystallization of Curium Coordination Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Samantha K.; Silver, Mark A.; Liu, Guokui; Wang, Jamie C.; Bogart, Justin A.; Stritzinger, Jared T.; Arico, Alexandra A.; Hanson, Kenneth; Schelter, Eric J.; Albrecht-Schmitt, Thomas E.

    2015-12-07

    The reaction of 248CmCl3 with excess 2,6-pyridinedicarboxylic acid (DPA) under mild solvothermal conditions results in crystallization of the tris-chelate complex Cm(HDPA)3·H2O. Approximately half of the curium remains in solution at the end of this process, and evaporation of the mother liquor results in crystallization of the bis-chelate complex [Cm(HDPA)- (H2DPA)(H2O)2Cl]Cl·2H2O. 248Cm is the daughter of the α decay of 252Cf and is extracted in high purity from this parent. However, trace amounts of 249,250,251Cf are still present in all samples of 248Cm. During the crystallization of Cm(HDPA)3·H2O and [Cm(HDPA)(H2DPA)(H2O)2Cl]Cl·2H2O, californium(III) spontaneously separates itself from the curium complexes and is found doped within crystals of DPA in the form of Cf(HDPA)3. These results add to the growing body of evidence that the chemistry of californium is fundamentally different from that of earlier actinides.

  7. Clinical Report on Californium-252 Neutron Intraluminal Brachytherapy Combined with External Irradiation for Cervical Carcinoma Treatment

    Institute of Scientific and Technical Information of China (English)

    Huanyu Zhao; Keming Wang; Jian Sun; Xin Geng; Weiming Zhang

    2006-01-01

    OBJECTIVE To observe the curative effects and complications of californium-252 (252Cf) neutron intraluminal brachytherapy (IBT) combined with external irradiation (El) for treatment of cervical carcinoma.METHODS From December 2000 to December 2004, 128 cases of cervical carcinoma staged into ⅡA~ⅢB according to the International Federation of Gynecology and Obstetrics (FIGO) standards were treated with 252Cf neutron IBT using 8~10 Gy per fraction, once a week. The total dose at reference A point was 36~40 Gy in 4~5 fractions. From the second day after 252Cf neutron IBT treatment, the whole pelvic cavity was treated with 60Co γ-ray El, applying 2 Gy per fraction, 4 times per week. After 20~25 Gy of El, the center of the whole pelvic field was blocked with 4 cm of lead in width. The total dose of El was 45~50 Gy.RESULTS The short-term therapeutic effects were CR 95.3% and PR 4.7%. The 3 and 5-year local control rates were 93.5% and 87.9%. The overall 3-year survival rate was 87.5% and for Stages Ⅱ and Ⅲ , 90.9%and 81.5% respectively; the overall 5-year survival rate was 70% and for Stages Ⅱ and Ⅲ, 76.2% and 61% respectively. The rate of radiation complications was 4.7% for radiation cystitis, 7.8% for radiation proctitis, 6.3%for vagina contracture and adhesion and 5.5% for protracted radiation proctitis.CONCLUSION An combination of 252Cf neutron IBT with El for treatment of cervical carcinoma can be well-tolerated by cervical carcinoma patients. The rate of local tumor control is high and radiation complications are few.

  8. Application of TSH bioindicator for studying the biological efficiency of neutrons from californium-252 source

    Energy Technology Data Exchange (ETDEWEB)

    Cebulska-Wasilewska, A.; Rekas, K. [Institute of Nuclear Physics, Cracow (Poland); Kim, J.K. [Korea Atomic Energy Research Inst., Taejon (Korea, Republic of)

    1997-12-31

    The effectiveness of neutrons from a Californium-252 source in the induction of various abnormalities in the Tradescantia clone 4430 stamen hair cells (TSH-assay) was studied. The special attention was paid to check whether any enhancement in effects caused by process of boron neutron capture is visible in the cells enriched with boron ions. Two chemicals (borax and BSH) were applied to introduce boron-10 ions into cells. Inflorescence, normal or pretreated with chemicals containing boron, were irradiated in the air with neutrons from a Cf-252 source at KAERI, Taejon, Korea. To estimate the relative biological effectiveness (RBE) in the induction of gene mutations of the neutron beam under the study, Tradescantia inflorescences, without any chemical pretreatment, were irradiated with various doses of X-rays. The ranges of radiation doses used were 0-0.1 Gy in neutrons and 0-0.5 Gy in X-rays. After the time needed to complete the postirradiation repair Tradescantia cuttings were transferred to Cracow, where screening of gene and lethal; mutations, cell cycle alterations in somatic cells have been done, and dose response relationships were figured. The maximal RBE values were estimated in the range of 4.6-6.8. Alterations of RBE value were observed; from 6.8 to 7.8 in the case of plants pretreated with 240 ppm of B-10 from borax, and 4.6 to 6.1 in the case of 400 ppm of B-10 from BSH. Results showed a slight, although statistically insignificant increase in biological efficacy of radiation from the Cf-252 source in samples pretreated with boron containing chemicals. (author)

  9. Study of the shielding for spontaneous fission sources of Californium-252; Estudio de blindaje para fuentes de fision espontanea de Californio-252

    Energy Technology Data Exchange (ETDEWEB)

    Davila R, I

    1991-06-15

    A shielding study is made to attenuate, until maximum permissible levels, the neutrons radiation and photons emitted by spontaneous fission coming from a source of Californium-252. The compound package by a database (Library DLC-23) and the ANISNW code is used, in it version for personal computer. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1976-01-01

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

  11. Development of electron beam ion source charge breeder for rare isotopes at Californium Rare Isotope Breeder Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Kondrashev, S.; Dickerson, C.; Levand, A.; Ostroumov, P. N.; Pardo, R. C.; Savard, G.; Vondrasek, R. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Alessi, J.; Beebe, E.; Pikin, A. [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Kuznetsov, G. I.; Batazova, M. A. [Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation)

    2012-02-15

    Recently, the Californium Rare Isotope Breeder Upgrade (CARIBU) to the Argonne Tandem Linac Accelerator System (ATLAS) was commissioned and became available for production of rare isotopes. Currently, an electron cyclotron resonance ion source is used as a charge breeder for CARIBU beams. To further increase the intensity and improve the purity of neutron-rich ion beams accelerated by ATLAS, we are developing a high-efficiency charge breeder for CARIBU based on an electron beam ion source (EBIS). The CARIBU EBIS charge breeder will utilize the state-of-the-art EBIS technology recently developed at Brookhaven National Laboratory (BNL). The electron beam current density in the CARIBU EBIS trap will be significantly higher than that in existing operational charge-state breeders based on the EBIS concept. The design of the CARIBU EBIS charge breeder is nearly complete. Long-lead components of the EBIS such as a 6-T superconducting solenoid and an electron gun have been ordered with the delivery schedule in the fall of 2011. Measurements of expected breeding efficiency using the BNL Test EBIS have been performed using a Cs{sup +} surface ionization ion source for external injection in pulsed mode. In these experiments we have achieved {approx}70% injection/extraction efficiency and breeding efficiency into the most abundant charge state of {approx}17%.

  12. Development of electron beam ion source charge breeder for rare isotopes at Californium Rare Isotope Breeder Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Kondrashev S.; Alessi J.; Dickerson, C.; Levand, A.; Ostroumov, P.N.; Pardo, R.C.; Savard, G.; Vondrasek, R.; Beebe, E.; Pikin, A.; Kuznetsov, G.I.; Batazova, M.A.

    2012-02-03

    Recently, the Californium Rare Isotope Breeder Upgrade (CARIBU) to the Argonne Tandem Linac Accelerator System (ATLAS) was commissioned and became available for production of rare isotopes. Currently, an electron cyclotron resonance ion source is used as a charge breeder for CARIBU beams. To further increase the intensity and improve the purity of neutron-rich ion beams accelerated by ATLAS, we are developing a high-efficiency charge breeder for CARIBU based on an electron beam ion source (EBIS). The CARIBU EBIS charge breeder will utilize the state-of-the-art EBIS technology recently developed at Brookhaven National Laboratory (BNL). The electron beam current density in the CARIBU EBIS trap will be significantly higher than that in existing operational charge-state breeders based on the EBIS concept. The design of the CARIBU EBIS charge breeder is nearly complete. Long-lead components of the EBIS such as a 6-T superconducting solenoid and an electron gun have been ordered with the delivery schedule in the fall of 2011. Measurements of expected breeding efficiency using the BNL Test EBIS have been performed using a Cs{sup +} surface ionization ion source for external injection in pulsed mode. In these experiments we have achieved {approx}70% injection/extraction efficiency and breeding efficiency into the most abundant charge state of {approx}17%.

  13. Californium Recovery from Palladium Wire

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-08-01

    The recovery of 252Cf from palladium-252Cf cermet wires was investigated to determine the feasibility of implementing it into the cermet wire production operation at Oak Ridge National Laboratory’s Radiochemical Engineering Development Center. The dissolution of Pd wire in 8 M HNO3 and trace amounts of HCl was studied at both ambient and elevated temperatures. These studies showed that it took days to dissolve the wire at ambient temperature and only 2 hours at 60°C. Adjusting the ratio of the volume of solvent to the mass of the wire segment showed little change in the kinetics of dissolution, which ranged from 0.176 mL/mg down to 0.019 mL/mg. A successful chromatographic separation of 153Gd, a surrogate for 252Cf, from Pd was demonstrated using AG 50x8 cation exchange resin with a bed volume of 0.5 mL and an internal diameter of 0.8 cm.

  14. Design of a homogeneous subcritical nuclear reactor based on thorium with a source of californium 252; Diseno de un reactor nuclear subcritico homogeneo a base de Torio con una fuente de Californio 252

    Energy Technology Data Exchange (ETDEWEB)

    Delgado H, C. E.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Sajo B, L., E-mail: ce_delgado89@hotmail.com [Universidad Simon Bolivar, Laboratorio de Fisica Nuclear, Apdo. 89000, 1080A Caracas (Venezuela, Bolivarian Republic of)

    2015-10-15

    Full text: One of the energy alternatives to fossil fuels which do not produce greenhouse gases is the nuclear energy. One of the drawbacks of this alternative is the generation of radioactive wastes of long half-life and its relation to the generation of nuclear materials to produce weapons of mass destruction. An option to these drawbacks of nuclear energy is to use Thorium as part of the nuclear fuel which it becomes in U{sup 233} when capturing neutrons, that is a fissile material. In this paper Monte Carlo methods were used to design a homogeneous subcritical reactor based on thorium. As neutron reflector graphite was used. The reactor core is homogeneous and is formed of 70% light water as moderator, 12% of enriched uranium UO{sub 2}(NO{sub 3}){sub 4} and 18% of thorium Th(NO{sub 3}){sub 4} as fuel. To start the nuclear fission chain reaction an isotopic source of californium 252 was used with an intensity of 4.6 x 10{sup 7} s{sup -1}. In the design the value of the effective multiplication factor, whose value turned out k{sub eff} <1 was calculated. Also, the neutron spectra at different distances from the source and the total fluence were calculated, as well as the values of the ambient dose equivalent in the periphery of the reactor. (Author)

  15. Manganese determination om minerals by activation analysis, using the californium-252 as a neutron source; Determinacao de manganes em minerios, por analise por ativacao, usando californio-252 como fonte de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Antonio

    1976-07-01

    Neutron Activation Analysis, using a Californium-252 neutron source, has been applied for the determination of manganese in ores such as pyrolusite, rodonite (manganese silicate)' and blending used in dry-batteries The favorable nuclear properties of manganese, such as high thermal neutron cross-section for the reaction {sup 55}Mn (n.gamma){sup 56} Mn, high concentration of manganese in the matrix and short half - life of {sup 56}Mn, are an ideal combination for non-destructive analysis of manganese in ores. Samples and standards of manganese dioxide were irradiated for about 20 minutes, followed by a 4 to 15 minutes decay and counted in a single channel pulse-height discrimination using a NaI(Tl) scintillation detector. Counting time was equal to 10 minutes. The interference of nuclear reactions {sup 56}Fe(n,p){sup 56}Mn and {sup 59} Co (n, {alpha}){sup 56} were studied, as well as problems in connection with neutron shadowing during irradiation, gamma-rays attenuation during counting and influence of granulometry of samples. One sample,was also analysed by wet-chemical method (sodium bismuthate) in order to compare results. As a whole, i t was shown that the analytical method of neutron activation for manganese in ores and blending, is a method simple, rapid and with good precision and accuracy. (author)

  16. Paired observation of californium-252 neutron intraluminal brachytherapy combined with external-beam radiotherapy with and without lead shielding for cervical cancer%252 Cf中子腔内照射结合挡铅与不挡铅外照射治疗宫颈癌的配对观察

    Institute of Scientific and Technical Information of China (English)

    戴卓捷; 雷新; 陈永红; 刘佳

    2015-01-01

    目的:比较252 Cf中子腔内照射结合挡铅盆腔对穿野和不挡铅箱式四野外照射治疗宫颈癌的治疗结果。方法2004—2007年本院收治的Ⅱa—Ⅲb 期的宫颈鳞癌患者,按照临床分期、年龄、肿瘤大小、贫血程度为配对条件,共筛选出26对(52例)研究对象,分为挡铅盆腔对穿野组(挡铅组)和不挡铅箱式四野组(不挡铅组)。两组患者外照射期间穿插252 Cf中子后装治疗。 Kaplan?Meier法计算5年LC、OS、DFS 并 Logrank 检验差异,晚期并发症发生率差异行 McNemar 法检验。结果挡铅、不挡铅组5年LC 率分别为85%、81%(P=0??014),OS 率分别为89%、73%(P=0??013),DFS 率分别为89%、73%(P=0??013),晚期并发症发生率分别为12%、23%(P=0??008)。结论腔内照射结合外照射治疗宫颈癌时无论采取对穿野还是箱式四野,后程前后野中央均应挡铅。%Objective To compare the efficacy between californium?252 ( 252 Cf ) neutron intraluminal brachytherapy combined with external?beam radiotherapy with lead?shielding pelvic parallel opposing field technique and non?lead?shielding four?field box technique for cervical cancer. Methods A total of 52 patients with stage Ⅱa?Ⅲb cervical squamous cell carcinoma who were admitted to our hospital from 2004 to 2007 were enrolled as subjects and paired by clinical stage, age, tumor size, and degree of anemia. The 26 pairs of patients were divided into lead?shielding pelvic parallel opposing field group (lead?shielding group) and non?lead?shielding four?field box group (non?lead?shielding group). For all patients in both groups, 252 Cf neutron brachytherapy was added in external?beam radiotherapy. The local control (LC), overall survival (OS), and disease?free survival (DFS) rates were calculated using the Kaplan?Meier method and analyzed using the log?rank test. The difference in the incidence of late complications was

  17. Time Series Analysis For The Californium Source In Sudbury Neutrino Observatory

    CERN Document Server

    Labranche, H

    2004-01-01

    The Sudbury Neutrino Observatory uses a 252Cf source to measure the neutron detection efficiency of its detector. We propose a method, the Time Series Analysis, that uses pairs of time intervals between the detected events to find the neutron detection efficiency, the probability to detect from a fission the prompt γ-rays, the neutron mean life inside the detector, the source fission rate and the residual activity rate from non-fission events. We explain our theoretical model of the source and the procedure to fit the data. With a 2.5 MeV threshold cut on the data, the neutron mean life is 5.281 ± 0.004(stat) msec and the source fission rate at June 12, 2001 is 4.360 ± 0.004(stat) sec −1. At this moment, the Time Series can only be applied to data when the source is near the centre. The technique is also applied with an AmBe source. We also show the latest progress to improve the technique. Finally, we briefly show another method, the Multiplicity Analysis, which was ...

  18. Design and Potentials of the Californium-252 Radiation Facility at WES

    Science.gov (United States)

    1975-09-01

    standards, using an Image Quality Indicator (IQI) and also a Beam Purity Indicator (BPI),** shows a relatively good thermal and epithermal neutron ...colli-nated beam of the desired neutron radiation. Consideration of the basic nuclear properties was therefore a necessity in achieving the desired...The upper 6 ft has been designed for use in radiography and neutron counting. The steel tank was prefabricated in two sections. The lower 6-ft

  19. Design of a californium-based epithermal neutron beam for neutron capture therapy.

    Science.gov (United States)

    Yanch, J C; Kim, J K; Wilson, M J

    1993-08-01

    The potential of the spontaneously fissioning isotope, 252Cf, to provide epithermal neutrons for use in boron neutron capture therapy (BNCT) has been investigated using Monte Carlo simulation. The Monte Carlo code MCNP was used to design an assembly composed of a 26 cm long, 11 cm radius cylindrical D2O moderator followed by a 64 cm long Al filter. Lithium filters are placed between the moderator and the filter and between the Al and the patient. A reflector surrounding the moderator/filter assembly is required in order to maintain adequate therapy flux at the patient position. An ellipsoidal phantom composed of skull- and brain-equivalent material was used to determine the dosimetric effect of this beam. It was found that both advantage depths and advantage ratios compare very favourably with reactor and accelerator epithermal neutron sources. The dose rate obtainable, on the other hand, is 4.1 RBE cGy min-1, based on a very large (1.0 g) source of 252Cf. This dose rate is two to five times lower than those provided by existing reactor beams and can be viewed as a drawback of using 252Cf as a neutron source. Radioisotope sources, however, do offer the advantage of in-hospital installation.

  20. Determination of the optimum-size californium-252 neutron source for borehole capture gamma-ray analysis

    Science.gov (United States)

    Senftle, F.E.; Macy, R.J.; Mikesell, J.L.

    1979-01-01

    The fast- and thermal-neutron fluence rates from a 3.7 ??g 252Cf neutron source in a simulated borehole have been measured as a function of the source-to-detector distance using air, water, coal, iron ore-concrete mix, and dry sand as borehole media. Gamma-ray intensity measurements were made for specific spectral lines at low and high energies for the same range of source-to-detector distances in the iron ore-concrete mix and in coal. Integral gamma-ray counts across the entire spectrum were also made at each source-to-detector distance. From these data, the specific neutron-damage rate, and the critical count-rate criteria, we show that in an iron ore-concrete mix (low hydrogen concentration), 252Cf neutron sources of 2-40 ??g are suitable. The source size required for optimum gamma-ray sensitivity depends on the energy of the gamma ray being measured. In a hydrogeneous medium such as coal, similar measurements were made. The results show that sources from 2 to 20 ??g are suitable to obtain the highest gamma-ray sensitivity, again depending on the energy of the gamma ray being measured. In a hydrogeneous medium, significant improvement in sensitivity can be achieved by using faster electronics; in iron ore, it cannot. ?? 1979 North-Holland Publishing Co.

  1. Optical transitions in highly charged californium ions with high sensitivity to variation of the fine-structure constant.

    Science.gov (United States)

    Berengut, J C; Dzuba, V A; Flambaum, V V; Ong, A

    2012-08-17

    We study electronic transitions in highly charged Cf ions that are within the frequency range of optical lasers and have very high sensitivity to potential variations in the fine-structure constant, α. The transitions are in the optical range despite the large ionization energies because they lie on the level crossing of the 5f and 6p valence orbitals in the thallium isoelectronic sequence. Cf(16+) is a particularly rich ion, having several narrow lines with properties that minimize certain systematic effects. Cf(16+) has very large nuclear charge and large ionization energy, resulting in the largest α sensitivity seen in atomic systems. The lines include positive and negative shifters.

  2. Keno-Nr a Monte Carlo Code Simulating the Californium -252-SOURCE-DRIVEN Noise Analysis Experimental Method for Determining Subcriticality

    Science.gov (United States)

    Ficaro, Edward Patrick

    The ^{252}Cf -source-driven noise analysis (CSDNA) requires the measurement of the cross power spectral density (CPSD) G_ {23}(omega), between a pair of neutron detectors (subscripts 2 and 3) located in or near the fissile assembly, and the CPSDs, G_{12}( omega) and G_{13}( omega), between the neutron detectors and an ionization chamber 1 containing ^{252}Cf also located in or near the fissile assembly. The key advantage of this method is that the subcriticality of the assembly can be obtained from the ratio of spectral densities,{G _sp{12}{*}(omega)G_ {13}(omega)over G_{11 }(omega)G_{23}(omega) },using a point kinetic model formulation which is independent of the detector's properties and a reference measurement. The multigroup, Monte Carlo code, KENO-NR, was developed to eliminate the dependence of the measurement on the point kinetic formulation. This code utilizes time dependent, analog neutron tracking to simulate the experimental method, in addition to the underlying nuclear physics, as closely as possible. From a direct comparison of simulated and measured data, the calculational model and cross sections are validated for the calculation, and KENO-NR can then be rerun to provide a distributed source k_ {eff} calculation. Depending on the fissile assembly, a few hours to a couple of days of computation time are needed for a typical simulation executed on a desktop workstation. In this work, KENO-NR demonstrated the ability to accurately estimate the measured ratio of spectral densities from experiments using capture detectors performed on uranium metal cylinders, a cylindrical tank filled with aqueous uranyl nitrate, and arrays of safe storage bottles filled with uranyl nitrate. Good agreement was also seen between simulated and measured values of the prompt neutron decay constant from the fitted CPSDs. Poor agreement was seen between simulated and measured results using composite ^6Li-glass-plastic scintillators at large subcriticalities for the tank of uranyl nitrate. It is believed that the response of these detectors is not well known and is incorrectly modeled in KENO-NR. In addition to these tests, several benchmark calculations were also performed to provide insight into the properties of the point kinetic formulation.

  3. Accurate determination of Curium and Californium isotopic ratios by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) in 248Cm samples for transmutation studies

    Energy Technology Data Exchange (ETDEWEB)

    Gourgiotis, A.; Isnard, H.; Aubert, M.; Dupont, E.; AlMahamid, I.; Cassette, P.; Panebianco, S.; Letourneau, A.; Chartier, F.; Tian, G.; Rao, L.; Lukens, W.

    2011-02-01

    The French Atomic Energy Commission has carried out several experiments including the mini-INCA (INcineration of Actinides) project for the study of minor-actinide transmutation processes in high intensity thermal neutron fluxes, in view of proposing solutions to reduce the radiotoxicity of long-lived nuclear wastes. In this context, a Cm sample enriched in {sup 248}Cm ({approx}97 %) was irradiated in thermal neutron flux at the High Flux Reactor (HFR) of the Laue-Langevin Institute (ILL). This work describes a quadrupole ICP-MS (ICP-QMS) analytical procedure for precise and accurate isotopic composition determination of Cm before sample irradiation and of Cm and Cf after sample irradiation. The factors that affect the accuracy and reproducibility of isotopic ratio measurements by ICP-QMS, such as peak centre correction, detector dead time, mass bias, abundance sensitivity and hydrides formation, instrumental background, and memory blank were carefully evaluated and corrected. Uncertainties of the isotopic ratios, taking into account internal precision of isotope ratio measurements, peak tailing, and hydrides formations ranged from 0.3% to 1.3%. This uncertainties range is quite acceptable for the nuclear data to be used in transmutation studies.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-04-24

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

  5. 78 FR 21567 - Installation of Radiation Alarms for Rooms Housing Neutron Sources

    Science.gov (United States)

    2013-04-11

    ... californium-252 (Cf-252). A licensee's decision to use a specific type of source may depend upon cost, availability, and the dependence upon historical data with which to compare current measurement results. The...

  6. A new shipping container for an intense neutron emitter

    Energy Technology Data Exchange (ETDEWEB)

    Bigelow, J.E.; Alexander, C.W.; Pace, J.V. III; Simmons, C.M.

    1994-06-01

    Californium-252 is an intense neutron emitter (2.34 {times} 10{sup 12} n/s{center_dot}g) used in medicine, research, and industry. The western world`s sole source of this rare radioisotope is the Californium Facility at Oak Ridge National Laboratory`s Radiochemical Engineering Development Center (REDC). A project has been initiated at the REDC to design a new Type B Californium Shipping Container. This effort is essential for future transportation of californium to meet the needs of users all over the world. The shipping container must meet all requirements for transport by motor freight, air, vessel, and rail, both domestic and foreign. There are unique problems in the design, fabrication, and licensing of a new Type B shipping container that will accommodate up to 60 milligrams of californium-252. One of the first challenges in the design phase of the project is the selection of a material to shield the high neutron flux. The more stringent safety precautions of today`s world impel us to consider more exotic materials for such a purpose. The candidate materials must be examined not just for their neutron shielding properties, but also in conjunction with other properties such as thermal and structural requirements to withstand the hypothetical accident conditions. The design and building of such a container is a formidable task requiring much planning. The licensing process, with the complex, interactive federal codes, is a special challenge and may be the biggest on the project in terms of time and money.

  7. Discovery of Isotopes of the Transuranium Elements with 93 <= Z <= 98

    CERN Document Server

    Fry, C

    2012-01-01

    One hundred and five isotopes of the transuranium elements neptunium, plutonium, americium, curium, berkelium and californium have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  8. Measurement of the energy spectra of fission fragments using nuclear track detectors and digital image processing

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa, Guillermo; Golzarri, Jose I. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, A.P. 20-364, Mexico D.F. 01000 (Mexico); Castano, Victor M., E-mail: castano@fata.unam.m [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, Boulevard Juriquilla 3001, Santiago de Queretaro, Queretaro 76230 (Mexico)

    2010-08-15

    Energy spectra of fission fragments were determined using a Nuclear Track Methodology (NTM) supported by digital image analysis and numerical data processing using a standard personal computer. The analysis of a californium ({sup 252}Cf) spectrum with this approach shows improvement compared with the values reported previously using the standard procedure, in terms of resolution and accuracy. This new method adds full automation to the technical advantages and cost effectiveness of an NTM.

  9. TOWARD AN IMPROVED UNDERSTANDING OF STRUCTURE AND MAGNETISM IN NEPTUNIUM AND PLUTONIUM PHOSPHONATES AND SULFONATES

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht-Schmitt, Thomas

    2012-03-01

    This grant supported the exploratory synthesis of new actinide materials with all of the actinides from thorium to californium with the exceptions of protactinium and berkelium. We developed detailed structure-property relationships that allowed for the identification of novel materials with selective ion-exchange, selective oxidation, and long-range magnetic ordering. We found novel bonding motifs and identified periodic trends across the actinide series. We identified structural building units that would lead to desired structural features and novel topologies. We also characterized many different spectroscopic trends across the actinide series. The grant support the preparation of approximately 1200 new compounds all of which were structurally characterized.

  10. Detection of rare earth elements in Powder River Basin sub-bituminous coal ash using laser-induced breakdown spectroscopy (LIBS)

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Phuoc [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United State; Mcintyre, Dustin [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United State

    2015-10-01

    We reported our preliminary results on the use of laser-induced breakdown spectroscopy to analyze the rare earth elements contained in ash samples from Powder River Basin sub-bituminous coal (PRB-coal). We have identified many elements in the lanthanide series (cerium, europium, holmium, lanthanum, lutetium, praseodymium, promethium, samarium, terbium, ytterbium) and some elements in the actinide series (actinium, thorium, uranium, plutonium, berkelium, californium) in the ash samples. In addition, various metals were also seen to present in the ash samples

  11. NONDESTRUCTIVE IDENTIFICATION OF CHEMICAL WARFARE AGENTS AND EXPLOSIVES BY NEUTRON GENERATOR-DRIVEN PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    T. R. Twomey; A. J. Caffrey; D. L. Chichester

    2007-02-01

    Prompt gamma-ray neutron activation analysis (PGNAA) is now a proven method for the identification of chemical warfare agents and explosives in military projectiles and storage containers. Idaho National Laboratory is developing a next-generation PGNAA instrument based on the new Ortec Detective mechanically-cooled HPGe detector and a neutron generator. In this paper we review PGNAA analysis of suspect chemical warfare munitions, and we discuss the advantages and disadvantages of replacing the californium-252 radioisotopic neutron source with a compact accelerator neutron generator.

  12. An ECR Charge Breeder for the 252 Cf Fission Source Project (CARIBU) at ATLAS%ATLAS用于CARIBU项目的ECR离子剥离器

    Institute of Scientific and Technical Information of China (English)

    R.C.Pardo; R.Vondrasek; T.Kulevoy; V.Aseev; R.Scott; P.Suominen

    2007-01-01

    A new radioactive beam facility for ATLAS,the Californium Rare Ion Breeder Upgrade(CARIBU),is under construction.The facility will use fission fragments from a 1 Ci 252 Cf source;thermalized and collected into a low-energy beam by a helium gas catcher.In order to reaccelerate these beams.the existing ATLAS ECR-I ion source is being redesigned to function as a charge breeder source.The design and features of this charge breeder configuration is discussed and the project status described.

  13. Advanced development of the spectrum sciences Model 5005-TF, single-event test fixture

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, M.R.; Browning, J.S. (Sandia National Labs., Albuquerque, NM (USA)); Hughlock, B.W. (Boeing Aerospace and Electronics Co., Seattle, WA (USA)); Lum, G.K. (Lockheed Missiles and Space Co., Sunnyvale, CA (USA)); Tsacoyeanes, W.C. (Draper (Charles Stark) Lab., Inc., Cambridge, MA (USA)); Weeks, M.D. (Spectrum Sciences, Inc., Santa Clara, CA (USA))

    1990-09-01

    This report summarizes the advanced development of the Spectrum Sciences Model 5005-TF, Single-Event Test Fixture. The Model 5005-TF uses a Californium-252 (Cf-252) fission-fragment source to test integrated circuits and other devices for the effects of single-event phenomena. Particle identification methods commonly used in high-energy physics research and nuclear engineering have been incorporated into the Model 5005-TF for estimating the particle charge, mass, and energy parameters. All single-event phenomena observed in a device under test (DUT) are correlated with an identified fission fragment, and its linear energy transfer (LET) and range in the semiconductor material of the DUT.

  14. Method for measuring multiple scattering corrections between liquid scintillators

    Science.gov (United States)

    Verbeke, J. M.; Glenn, A. M.; Keefer, G. J.; Wurtz, R. E.

    2016-07-01

    A time-of-flight method is proposed to experimentally quantify the fractions of neutrons scattering between scintillators. An array of scintillators is characterized in terms of crosstalk with this method by measuring a californium source, for different neutron energy thresholds. The spectral information recorded by the scintillators can be used to estimate the fractions of neutrons multiple scattering. With the help of a correction to Feynman's point model theory to account for multiple scattering, these fractions can in turn improve the mass reconstruction of fissile materials under investigation.

  15. PROCEEDINGS OF THE SYMPOSIUM COMMEMORATING THE 25th ANNIVERSARY OF ELEMENTS 97 and 98 HELD ON JAN. 20, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Seaborg, Glenn T.; Street Jr., Kenneth; Thompson, Stanley G.; Ghiorso, Albert

    1976-07-01

    This volume includes the talks given on January 20, 1975, at a symposium in Berkeley on the occasion of the celebration of the 25th anniversary of the discovery of berkelium and californium. Talks were given at this symposium by the four people involved in the discovery of these elements and by a number of people who have made significant contributions in the intervening years to the investigation of their nuclear and chemical properties. The papers are being published here, without editing, in the form in which they were submitted by the authors in the months following the anniversary symposium, and they reflect rather faithfully the remarks made on that occasion.

  16. Improved charge breeding efficiency of light ions with an electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Vondrasek, R.; Kutsaev, Sergey [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Delahaye, P.; Maunoury, L. [Grand Accelerateur National d' Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, Blvd Henri Becquerel, 14076 Caen (France)

    2012-11-15

    The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a {sup 252}Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficiencies of both gaseous and solid species including 14.7% for the radioactive species {sup 143}Ba{sup 27+}. In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for {sup 23}Na{sup 7+} and 17.9% for {sup 39}K{sup 10+} were obtained injecting stable Na{sup +} and K{sup +} beams from a surface ionization source.

  17. Triton and alpha-particle contribution from LiF converter for neutron dosimeter

    CERN Document Server

    Camacho, M E; Balcazar, M

    1999-01-01

    A personnel neutron dosimeter prototype based on chemical and electrochemical etched CR-39 detector, combined with LiF converter, has been calibrated using an ICRP-like phantom, under a heavy-water moderated Californium source neutron spectra; A conversion factor of 1.052+-126 spots cm sup - sup 2 mSv sup - sup 1 was obtained. The sealing properties of the detector holder showed a ten-fold reduction in radon background when it was tested in a high radon atmosphere. A convenient mechanical shock resistance was achieved in LiF converters by sintering to 11 tons pressure LiF powder at 650 deg. C, during one hour.

  18. Reliability of semiconductor and gas-filled diodes for over-voltage protection exposed to ionizing radiation

    Directory of Open Access Journals (Sweden)

    Stanković Koviljka

    2009-01-01

    Full Text Available The wide-spread use of semiconductor and gas-filled diodes for non-linear over-voltage protection results in a variety of possible working conditions. It is therefore essential to have a thorough insight into their reliability in exploitation environments which imply exposure to ionizing radiation. The aim of this paper is to investigate the influence of irradiation on over-voltage diode characteristics by exposing the diodes to californium-252 combined neutron/gamma radiation field. The irradiation of semiconductor over-voltage diodes causes severe degradation of their protection characteristics. On the other hand, gas-filled over-voltage diodes exhibit a temporal improvement of performance. The results are presented with the accompanying theoretical interpretations of the observed changes in over-voltage diode behaviour, based on the interaction of radiation with materials constituting the diodes.

  19. First results from the CARIBU facility: mass measurements on the r-process path.

    Science.gov (United States)

    Van Schelt, J; Lascar, D; Savard, G; Clark, J A; Bertone, P F; Caldwell, S; Chaudhuri, A; Levand, A F; Li, G; Morgan, G E; Orford, R; Segel, R E; Sharma, K S; Sternberg, M G

    2013-08-09

    The Canadian Penning Trap mass spectrometer has made mass measurements of 33 neutron-rich nuclides provided by the new Californium Rare Isotope Breeder Upgrade facility at Argonne National Laboratory. The studied region includes the 132Sn double shell closure and ranges in Z from In to Cs, with Sn isotopes measured out to A=135, and the typical measurement precision is at the 100 ppb level or better. The region encompasses a possible major waiting point of the astrophysical r process, and the impact of the masses on the r process is shown through a series of simulations. These first-ever simulations with direct mass information on this waiting point show significant increases in waiting time at Sn and Sb in comparison with commonly used mass models, demonstrating the inadequacy of existing models for accurate r-process calculations.

  20. Nuclear fission and the transuranium elements

    Energy Technology Data Exchange (ETDEWEB)

    Seaborg, G.T.

    1989-02-01

    Many of the transuranium elements are produced and isolated in large quantities through the use of neutrons furnished by nuclear fission reactions: plutonium (atomic number 94) in ton quantities; neptunium (93), americium (95), and curium (96) in kilogram quantities; berkelium (97) in 100 milligram quantities; californium (98) in gram quantities; and einsteinium (99) in milligram quantities. Transuranium isotopes have found many practical applications---as nuclear fuel for the large-scale generation of electricity, as compact, long-lived power sources for use in space exploration, as means for diagnosis and treatment in the medical area, and as tools in numerous industrial processes. Of particular interest is the unusual chemistry and impact of these heaviest elements on the periodic table. This account will feature these aspects. 9 refs., 5 figs.

  1. Production of highly pure einsteinium and fermium preparations

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, O.I.; Tarasov, V.A.; Zotov, E.A.; Baranov, A.Yu. [Federal State Unitary Enterprise ' ' State Scientific Center of Russian Federation Research Institute of Atomic Reactors' ' (Russian Federation)

    2004-07-01

    Highly pure einsteinium and fermium preparations are in increased demand due to the progress of the following fields of modern sciences: Fundamental and applied nuclear physics. Heavy actinides are necessary for detailed study of structure and decay of a nucleus, as well as initial material both for nuclear synthesis of new superheavy elements and for manufacturing radioactive radiation sources. Fundamental and applied radiochemistry. Einsteinium and fermium preparations are required to investigate chemical properties of these hard-to-obtain elements and to improve technology of their recovery and purification. Nuclear medicine. Biologically active compounds labeled with alpha- emitting einsteinium and fermium may be applied in prospect for a radioimmunotherapy of oncological diseases. The principal method of einsteinium and fermium production is irradiation of curium or californium isotopes in a high-flux nuclear reactor. Large-scale production of transplutonium elements at RIAR enables also to produce regularly significant quantities of einsteinium and fermium. (orig.)

  2. Beta-delayed neutron spectroscopy using ion traps

    Science.gov (United States)

    Wang, Barbara; Czeszumska, A.; Siegl, K.; Caldwell, S.; Aprahamian, A.; Burkey, M.; Clark, J.; Levand, A.; Marley, S.; Morgan, G.; Norman, E.; Nystrom, A.; Orford, R.; Padgett, S.; Perez Galvan, A.; Savard, G.; Scielzo, N.; Sharma, K.; Strauss, S.

    2017-01-01

    Trapped radioactive ions suspended in vacuum allow for a new way to perform beta-delayed neutron spectroscopy. Decay branching ratios and energy spectra of the emitted neutrons are inferred from a measurement of the nuclear recoil, thereby circumventing the many limitations associated with direct neutron detection. Beta-delayed neutron measurements were carried out for 137-138,140I, 134-136Sb, and 144-145Cs at the Californium Rare Isotope Breeder Upgrade (CARIBU) facility at Argonne National Laboratory. The data collected are needed in many fields of basic and applied science such as nuclear energy, nuclear astrophysics, and stockpile stewardship. Results for the isotopes 135-136Sb and 140I will be presented. Supported by NSF under PHY-1419765, and U.S. DOE under NEUP 13-5485, DE-AC02-06CH11357 (ANL), DE-AC52-07NA27344 (LLNL), and DE-NA0000979 (NNSA).

  3. Environmental assessment of the thermal neutron activation explosive detection system for concourse use at US airports

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.G.

    1990-08-01

    This document is an environmental assessment of a system designed to detect the presence of explosives in checked airline baggage or cargo. The system is meant to be installed at the concourse or lobby ticketing areas of US commercial airports and uses a sealed radioactive source of californium-252 to irradiate baggage items. The major impact of the use of this system arises from direct exposure of the public to scattered or leakage radiation from the source and to induced radioactivity in baggage items. Under normal operation and the most likely accident scenarios, the environmental impacts that would be created by the proposed licensing action would not be significant. 44 refs., 19 figs., 18 tabs.

  4. TRIGA-TRAP: A penning trap mass spectrometer at the research reactor TRIGA Mainz

    Energy Technology Data Exchange (ETDEWEB)

    Smorra, Christian [Physikalisches Institut, Universitaet Heidelberg (Germany); Institut fuer Kernchemie, Universitaet Mainz (Germany); Blaum, Klaus [Physikalisches Institut, Universitaet Heidelberg (Germany); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Block, Michael; Herfurth, Frank [GSI, Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Eberhardt, Klaus [Institut fuer Kernchemie, Universitaet Mainz (Germany); Eibach, Martin; Ketelaer, Jens; Ketter, Jochen; Knuth, Konstantin; Repp, Julia [Institut fuer Physik, Universitaet Mainz (Germany); Nagy, Szilard [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2009-07-01

    Nuclear masses represent the binding energies and, therefore, the sum of all interactions in the nucleus. They provide an important input parameter to nuclear structure models. Presently, a tremendous interest in masses of very exotic neutron-rich nuclides exists to support theoretical models for the nucleosynthesis via the rapid neutron capture process. The research reactor TRIGA Mainz provides access to a large variety of neutron-rich nuclides produced by thermal-neutron induced fission of an actinide target. The double-Penning trap mass spectrometer TRIGA-TRAP will perform high-precision mass measurements in this region of the nuclear chart as well as on actinides from uranium to californium. It also serves as a test facility for the development of new techniques that will be implemented in future facilities like MATS at FAIR (GSI, Darmstadt). The layout of TRIGA-TRAP as well as recent mass measurements are presented.

  5. Populations of selected microbial and fungal species growing on the surface of rape seeds following treatment with desiccants or plant growth regulators.

    Science.gov (United States)

    Frac, Magdalena; Jezierska-Tys, Stefania; Tys, Jerzy

    2010-01-01

    The aim of this study was to determine the effects of desiccants and plant growth regulators on selected microbial species affecting rape seeds, with special emphasis on the growth of fungi and identification of the genus and species composition. The experimental material in the study was seeds of winter rape cv. Californium that were collected from the field during combine harvest. The chemical agents applied, both desiccants and growth regulators, generally decreased the populations of bacteria occurring on the surface of rape seeds. The responses of fungi depended upon the type of agent applied and were manifested as either stimulation or inhibition of the growth of the fungal species. The fungi isolated from the surface of rape seeds were characteristic of those found in the field environment (Cladosporium and Penicillium) and typical for those present on the surface of rape seeds (Alternaria).

  6. Measurements of the neutron capture cross sections and incineration potentials of minor-actinides in high thermal neutron fluxes: Impact on the transmutation of nuclear wastes; Mesures des sections efficaces de capture et potentiels d'incineration des actinides mineurs dans les hauts flux de neutrons: Impact sur la transmutation des dechets

    Energy Technology Data Exchange (ETDEWEB)

    Bringer, O

    2007-10-15

    This thesis comes within the framework of minor-actinide nuclear transmutation studies. First of all, we have evaluated the impact of minor actinide nuclear data uncertainties within the cases of {sup 241}Am and {sup 237}Np incineration in three different reactor spectra: EFR (fast), GT-MHR (epithermal) and HI-HWR (thermal). The nuclear parameters which give the highest uncertainties were thus highlighted. As a result of fact, we have tried to reduce data uncertainties, in the thermal energy region, for one part of them through experimental campaigns in the moderated high intensity neutron fluxes of ILL reactor (Grenoble). These measurements were focused onto the incineration and transmutation of the americium-241, the curium-244 and the californium-249 isotopes. Finally, the values of 12 different cross sections and the {sup 241}Am isomeric branching ratio were precisely measured at thermal energy point. (author)

  7. Neutron Detector Signal Processing to Calculate the Effective Neutron Multiplication Factor of Subcritical Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Talamo, Alberto [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Gohar, Yousry [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2016-06-01

    This report describes different methodologies to calculate the effective neutron multiplication factor of subcritical assemblies by processing the neutron detector signals using MATLAB scripts. The subcritical assembly can be driven either by a spontaneous fission neutron source (e.g. californium) or by a neutron source generated from the interactions of accelerated particles with target materials. In the latter case, when the particle accelerator operates in a pulsed mode, the signals are typically stored into two files. One file contains the time when neutron reactions occur and the other contains the times when the neutron pulses start. In both files, the time is given by an integer representing the number of time bins since the start of the counting. These signal files are used to construct the neutron count distribution from a single neutron pulse. The built-in functions of MATLAB are used to calculate the effective neutron multiplication factor through the application of the prompt decay fitting or the area method to the neutron count distribution. If the subcritical assembly is driven by a spontaneous fission neutron source, then the effective multiplication factor can be evaluated either using the prompt neutron decay constant obtained from Rossi or Feynman distributions or the Modified Source Multiplication (MSM) method.

  8. On-line charge breeding using ECRIS and EBIS

    Science.gov (United States)

    Vondrasek, Richard

    2016-06-01

    The efficient and rapid production of a high-quality, pure beam of highly charged ions is at the heart of any radioactive ion beam facility. Whether an electron cyclotron resonance (ECR) ion source or an electron beam ion source (EBIS) is used to produce these highly charged ions, their operating characteristics will set the boundaries on the range of experiments which can be performed. In addition, time structure and duty cycle have to be considered when defining the operating parameters of the accelerator system as a whole. At Argonne National Laboratory (ANL), an ECR charge breeder was developed as part of the Californium Rare Ion Breeder Upgrade (CARIBU) program. The charge breeding efficiency and high charge state production of the source is at the forefront of ECR charge breeders, but its overall performance as part of the accelerator system is limited by pervasive background and relatively long breeding times. As such, an EBIS charge breeder has been developed and is running in an off-line configuration. It has already demonstrated good breeding efficiencies, shorter residence times, and reduced background and is scheduled to replace the ECR charge breeder in late 2015. The resultant change in duty cycle and time structure necessitates changes to the overall operation of the facility. The experiences with these breeders, as well as from several other facilities which already utilize an ECR or EBIS for charge breeding, help to define the operational characteristics of each technology - their strengths, their weaknesses, and the possible paths to improvement.

  9. γ -soft Ba146 and the role of nonaxial shapes at N90

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, A. J.; Lister, C. J.; McCutchan, E. A.; Albers, M.; Ayangeakaa, A. D.; Bertone, P. F.; Carpenter, M. P.; Chiara, C. J.; Chowdhury, P.; Clark, J. A.; Copp, P.; David, H. M.; Deo, A. Y.; DiGiovine, B.; D' Olympia, N.; Dungan, R.; Harding, R. D.; Harker, J.; Hota, S. S.; Janssens, R. V. F.; Kondev, F. G.; Liu, S. H.; Ramayya, A. V.; Rissanen, J.; Savard, G.; Seweryniak, D.; Shearman, R.; Sonzogni, A. A.; Tabor, S. L.; Walters, W. B.; Wang, E.; Zhu, S.

    2016-01-01

    Low-spin states in the neutron-rich, N=90 nuclide Ba146 were populated following β decay of Cs146, with the goal of clarifying the development of deformation in barium isotopes through delineation of their nonyrast structures. Fission fragments of Cs146 were extracted from a 1.7-Ci Cf252 source and mass selected using the CAlifornium Rare Ion Breeder Upgrade (CARIBU) facility. Low-energy ions were deposited at the center of a box of thin β detectors, surrounded by a highly efficient high-purity Ge array. The new Ba146 decay scheme now contains 31 excited levels extending up to ~2.5 MeV excitation energy, double what was previously known. These data are compared to predictions from the interacting boson approximation (IBA) model. It appears that the abrupt shape change found at N=90 in Sm and Gd is much more gradual in Ba and Ce, due to an enhanced role of the γ degree of freedom.

  10. Significant relationships among frost tolerance and net photosynthetic rate, water use efficiency and dehydrin accumulation in cold-treated winter oilseed rapes.

    Science.gov (United States)

    Urban, Milan Oldřich; Klíma, Miroslav; Vítámvás, Pavel; Vašek, Jakub; Hilgert-Delgado, Alois Albert; Kučera, Vratislav

    2013-12-15

    Five winter oilseed rape cultivars (Benefit, Californium, Cortes, Ladoga, Navajo) were subjected to 30 days of cold treatment (4 °C) to examine the effect of cold on acquired frost tolerance (FT), dehydrin (DHN) content, and photosynthesis-related parameters. The main aim of this study was to determine whether there are relationships between FT (expressed as LT50 values) and the other parameters measured in the cultivars. While the cultivar Benefit accumulated two types of DHNs (D45 and D35), the other cultivars accumulated three additional DHNs (D97, D47, and D37). The similar-sized DHNs (D45 and D47) were the most abundant; the others exhibited significantly lower accumulations. The highest correlations were detected between LT50 and DHN accumulation (r=-0.815), intrinsic water use efficiency (WUEi; r=-0.643), net photosynthetic rate (r=-0.628), stomatal conductance (r=0.511), and intracellular/intercellular CO2 concentration (r=0.505). Those cultivars that exhibited higher Pn rate in cold (and further a significant increase in WUEi) had higher levels of DHNs and also higher FT. No significant correlation was observed between LT50 and E, PRI, or NDVI. Overall, we have shown the selected physiological parameters to be able to distinguish different FT cultivars of winter oilseed rape.

  11. Studies of Beta-Delayed Neutron Emission using Trapped Ions

    Science.gov (United States)

    Siegl, Kevin; Aprahamian, A.; Scielzo, N. D.; Savard, G.; Clark, J. A.; Levand, A. F.; Burkey, M.; Caldwell, S.; Czeszumska, A.; Hirsh, T. Y.; Kolos, K.; Marley, S. T.; Morgan, G. E.; Norman, E. B.; Nystrom, A.; Orford, R.; Padgett, S.; Pérez Galván, A.; Sh, K. S.; Strauss, S. Y.; Wang, B. S.

    2017-01-01

    Using a radio-frequency quadrupole ion trap to confine radioactive ions allows indirect measurements of beta-delayed neutron (BDN) emission. By determining the recoil energy of the beta-decay daughter ions it is possible to study BDN emission, as the neutron emission can impart a significantly larger nuclear recoil than from beta-decay alone. This method avoids most of the systematic uncertainties associated with direct neutron detection but introduces dependencies on the specifics of the decay and interactions of the ion with the RF fields. The decays of seven BDN precursors were studied using the Beta-decay Paul Trap (BPT) to confine fission fragments from the Californium Rare Isotope Breeder Upgrade (CARIBU) facility at Argonne National Laboratory. The analysis of these measurements and results for the branching ratios and neutron energy spectra will be presented. Supported by the NSF under grant PHY-1419765, and the U.S. DOE under the NEUP project 13-5485, contracts DE-AC02-06CH11357 (ANL) and DE-AC52-07NA27344 (LLNL), and award DE-NA0000979 (NNSA).

  12. Production of Medical Radioisotopes in the ORNL High Flux Isotope Reactor (HFIR) for Cancer Treatment and Arterial Restenosis Therapy after PTCA

    Science.gov (United States)

    Knapp, F. F. Jr.; Beets, A. L.; Mirzadeh, S.; Alexander, C. W.; Hobbs, R. L.

    1998-06-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube (HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions (PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed.

  13. Extraction studies of selected actinide ions from aqueous solutions with 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione and tri-n-octylphosphine oxide

    Energy Technology Data Exchange (ETDEWEB)

    Hannink, N.J.; Hoffman, D.C. [Lawrence Berkeley Lab., CA (United States)]|[California Univ., Berkeley, CA (United States). Dept. of Chemistry; Smith, B.F. [Los Alamos National Lab., NM (United States)

    1991-11-01

    The first measurements of distribution coefficients (K{sub d}) for Cm(III), Bk(III), Cf(III), Es(III), and Fm(III) between aqueous perchlorate solutions and solutions of 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT) and the synergist tri-n-octylphosphine oxide (TOPO) in toluene are reported. Curium-243, berkelium-250, californium-249, einsteinium-254, and fermium-253 were used in these studies. The K{sub d} for {sup 241}Am was also measured and is in agreement with previously published results. Our new results show that the K{sub d}`s decrease gradually with increasing atomic number for the actinides with a dip at Cf. In general, the K{sub d}`s for these actinides are about a factor of 5 to 10 greater than the K{sub d}`s for the homologous lanthanides at a pH of 2.9, a BMPPT concentration of 0.2 M, and a TOPO concentration of 0.04 M. The larger K{sub d}`s for the actinides are consistent with greater covalent bonding between the actinide metal ion and the sulfur bonding site in the ligand.

  14. Extraction studies of selected actinide ions from aqueous solutions with 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione and tri-n-octylphosphine oxide

    Energy Technology Data Exchange (ETDEWEB)

    Hannink, N.J.; Hoffman, D.C. (Lawrence Berkeley Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Chemistry); Smith, B.F. (Los Alamos National Lab., NM (United States))

    1991-11-01

    The first measurements of distribution coefficients (K{sub d}) for Cm(III), Bk(III), Cf(III), Es(III), and Fm(III) between aqueous perchlorate solutions and solutions of 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT) and the synergist tri-n-octylphosphine oxide (TOPO) in toluene are reported. Curium-243, berkelium-250, californium-249, einsteinium-254, and fermium-253 were used in these studies. The K{sub d} for {sup 241}Am was also measured and is in agreement with previously published results. Our new results show that the K{sub d}'s decrease gradually with increasing atomic number for the actinides with a dip at Cf. In general, the K{sub d}'s for these actinides are about a factor of 5 to 10 greater than the K{sub d}'s for the homologous lanthanides at a pH of 2.9, a BMPPT concentration of 0.2 M, and a TOPO concentration of 0.04 M. The larger K{sub d}'s for the actinides are consistent with greater covalent bonding between the actinide metal ion and the sulfur bonding site in the ligand.

  15. Extraction studies of selected actinide ions from aqueous solutions with 4-benzoyl-2,4-Dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione and Tri-n-octylphosphine oxide

    Energy Technology Data Exchange (ETDEWEB)

    Hannink, N.J.; Hoffman, D.C. [Lawrence Berkeley Lab., CA (United States); Smith, B.F. [Los Alamos National Lab., NM (United States)

    1992-07-01

    The first measurements of distribution coefficients (k{sub d}) for Cm(III), Bk(III), Cf(III), Es(III), and Fm(III) between aqueous perchlorate solutions and solutions of 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT) and the synergist tri-n-octylphosphine oxide (TOPO) in toluene are reported. Curium-243, berkelium-250, californium-249, einsteinium-254, and fermium-253 were used in these studies. The K{sub d} for {sup 241}Am was also measured and is in agreement with previously published results. Our new results show that the K{sub d}`s decrease gradually with increasing atomic number for the actinides with a dip at Cf. In general, the K{sub d}`s for these actinides are about about a factor of 10 greater than the K{sub d}`s for the homologous lanthanides at a pH of 2.9, a BMPPT concentration of 0.2 M, and a TOPO concentration of 0.04 M. The larger K{sub d}`s for the actinides are consistent with greater covalent bonding between the actinide metal ion and the sulfur bonding site in the ligand. 9 refs., 2 figs., 1 tab.

  16. Recovery and chemical purification of actinides at JRC, Karlsruhe

    Science.gov (United States)

    Bokelund, H.; Apostolidis, C.; Glatz, J.-P.

    1989-07-01

    The application of actinide elements in research and in technology is many times subject to rather stringent purity requirements; often a nuclear grade quality is specified. The additional possible demand for a high isotopic purity is a special feature in the handling of these elements. The amount of actinide elements contained in or adhering to materials declared as waste should be low for safety reasons and out of economic considerations. The release of transuranium elements to the environment must be kept negligible. For these and for other reasons a keen interest in the separation of actinides from various materials exists, either for a re-use through recycling, or for their safe confinement in waste packages. This paper gives a short review of the separation methods used for recovery and purification of actinide elements over the past years in the European Institute for Transuranium Elements. The methods described here involve procedures based on precipitation, ion exchange or solvent extraction; often used in a combination. The extraction methods were preferably applied in a Chromatographie column mode. The actinide elements purified and/or separated from each other by the above methods include uranium, neptunium, plutonium, americium, curium, and californium. For the various elements the work was undertaken with different aims, ranging from reprocessing and fabrication of nuclear fuels on a kilogramme scale, over the procurement of alpha-free waste, to the preparation of neutron sources of milligramme size.

  17. Production of medical radioisotopes in the ORNL High Flux Isotope Reactor (HFIR) for cancer treatment and arterial restenosis therapy after PTCA

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, F.F. Jr.; Beets, A.L.; Mirzadeh, S.; Alexander, C.W.; Hobbs, R.L.

    1998-06-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube (HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions (PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed.

  18. Compensated bismuth-loaded plastic scintillators for neutron detection using low-energy pseudo-spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dumazert, Jonathan, E-mail: jonathan.dumazert@cea.fr [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 91191 Gif-sur-Yvette (France); Coulon, Romain; Bertrand, Guillaume H.V.; Normand, Stéphane [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 91191 Gif-sur-Yvette (France); Méchin, Laurence [CNRS, UCBN, Groupe de Recherche en Informatique, Image, Automatique et Instrumentation de Caen, 14050 Caen (France); Hamel, Matthieu [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 91191 Gif-sur-Yvette (France)

    2016-05-21

    Gadolinium-covered modified plastic scintillators show a high potential for the deployment of cost-effective neutron detectors. Taking advantage of the low-energy photon and electron signature of thermal neutron captures in gadolinium-155 and gadolinium-157 however requires a background correction. In order to display a trustable rate, dual compensation schemes appear as an alternative to Pulse Shape Discrimination. This paper presents the application of such a compensation scheme to a two-bismuth loaded plastic scintillator system. A detection scintillator interacts with incident photon and fast neutron radiations and is covered with a gadolinium converter to become thermal neutron-sensitive as well. In the meantime, an identical compensation scintillator, covered with terbium, solely interacts with the photon and fast neutron part of incident radiations. After the acquisition and the treatment of the counting signals from both sensors, a hypothesis test determines whether the resulting count rate after subtraction falls into statistical fluctuations or provides a robust image of neutron activity. A laboratory prototype is tested under both photon and neutron radiations, allowing us to investigate the performance of the overall compensation system. The study reveals satisfactory results in terms of robustness to a cesium-137 background and in terms of sensitivity in presence of a californium-252 source.

  19. Fast neutron tomography with real-time pulse-shape discrimination in organic scintillation detectors

    Science.gov (United States)

    Joyce, Malcolm J.; Agar, Stewart; Aspinall, Michael D.; Beaumont, Jonathan S.; Colley, Edmund; Colling, Miriam; Dykes, Joseph; Kardasopoulos, Phoevos; Mitton, Katie

    2016-10-01

    A fast neutron tomography system based on the use of real-time pulse-shape discrimination in 7 organic liquid scintillation detectors is described. The system has been tested with a californium-252 source of dose rate 163 μSv/h at 1 m and neutron emission rate of 1.5×107 per second into 4π and a maximum acquisition time of 2 h, to characterize two 100×100×100 mm3 concrete samples. The first of these was a solid sample and the second has a vertical, cylindrical void. The experimental data, supported by simulations with both Monte Carlo methods and MATLAB®, indicate that the presence of the internal cylindrical void, corners and inhomogeneities in the samples can be discerned. The potential for fast neutron assay of this type with the capability to probe hydrogenous features in large low-Z samples is discussed. Neutron tomography of bulk porous samples is achieved that combines effective penetration not possible with thermal neutrons in the absence of beam hardening.

  20. A review of neutron scattering correction for the calibration of neutron survey meters using the shadow cone method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang In; Kim, Bong Hwan; Kim, Jang Lyul; Lee, Jung Il [Health Physics Team, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-12-15

    The calibration methods of neutron-measuring devices such as the neutron survey meter have advantages and disadvantages. To compare the calibration factors obtained by the shadow cone method and semi-empirical method, 10 neutron survey meters of five different types were used in this study. This experiment was performed at the Korea Atomic Energy Research Institute (KAERI; Daejeon, South Korea), and the calibration neutron fields were constructed using a {sup 252}Californium ({sup 252}Cf) neutron source, which was positioned in the center of the neutron irradiation room. The neutron spectra of the calibration neutron fields were measured by a europium-activated lithium iodide scintillator in combination with KAERI's Bonner sphere system. When the shadow cone method was used, 10 single moderator-based survey meters exhibited a smaller calibration factor by as much as 3.1 - 9.3% than that of the semi-empirical method. This finding indicates that neutron survey meters underestimated the scattered neutrons and attenuated neutrons (i.e., the total scatter corrections). This underestimation of the calibration factor was attributed to the fact that single moderator-based survey meters have an under-ambient dose equivalent response in the thermal or thermal-dominant neutron field. As a result, when the shadow cone method is used for a single moderator-based survey meter, an additional correction and the International Organization for Standardization standard 8529-2 for room-scattered neutrons should be considered.

  1. Active Neutron Interrogation of Non-Radiological Materials with NMIS

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Mark E [ORNL; Mihalczo, John T [ORNL

    2012-02-01

    The Nuclear Materials Identification System (NMIS) at Oak Ridge National Laboratory (ORNL), although primarily designed for analyzing special nuclear material, is capable of identifying nonradiological materials with a wide range of measurement techniques. This report demonstrates four different measurement methods, complementary to fast-neutron imaging, which can be used for material identification: DT transmission, DT scattering, californium transmission, and active time-tagged gamma spectroscopy. Each of the four techniques was used to evaluate how these methods can be used to identify four materials: aluminum, polyethylene, graphite, and G-10 epoxy. While such measurements have been performed individually in the past, in this project, all four measurements were performed on the same set of materials. The results of these measurements agree well with predicted results. In particular, the results of the active gamma spectroscopy measurements demonstrate the technique's applicability in a future version of NMIS which will incorporate passive and active gamma-ray spectroscopy. This system, designated as a fieldable NMIS (FNMIS), is under development by the US Department of Energy Office of Nuclear Verification.

  2. X-ray Measurements of a Thermo Scientific P385 DD Neutron Generator

    Energy Technology Data Exchange (ETDEWEB)

    E.H. Seabury; D.L. Chichester; A.J. Caffrey; J. Simpson; M. Lemchak; C.J. Wharton

    2001-08-01

    Idaho National Laboratory is experimenting with electrical neutron generators, as potential replacements for californium-252 radioisotopic neutron sources in its PINS prompt gamma-ray neutron activation analysis (PGNAA) system for the identification of military chemical warfare agents and explosives. In addition to neutron output, we have recently measured the x-ray output of the Thermo Scientific P385 deuterium-deuterium neutron generator. X-rays are a normal byproduct from a neutron generator and depending on their intensity and energy they can interfere with gamma rays from the object under test, increase gamma-spectrometer dead time, and reduce PGNAA system throughput. The P385 x-ray energy spectrum was measured with a high-purity germanium (HPGe) detector, and a broad peak is evident at about 70 keV. To identify the source of the x-rays within the neutron generator assembly, it was scanned by collimated scintillation detectors along its long axis. At the strongest x-ray emission points, the generator also was rotated 60° between measurements. The scans show the primary source of x-ray emission from the P385 neutron generator is an area 60 mm from the neutron production target, in the vicinity of the ion source. Rotation of the neutron generator did not significantly alter the x-ray count rate, and the x-ray emission appears to be axially symmetric within the neutron generator.

  3. An Account of Oak Ridge National Laboratory's Thirteen Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rosenthal, Murray Wilford [ORNL

    2009-08-01

    The Oak Ridge National Laboratory has built and operated 13 nuclear reactors in its 66-year history. The first was the graphite reactor, the world's first operational nuclear reactor, which served as a plutonium production pilot plant during World War II. It was followed by two aqueous-homogeneous reactors and two red-hot molten-salt reactors that were parts of power-reactor development programs and by eight others designed for research and radioisotope production. One of the eight was an all-metal fast burst reactor used for health physics studies. All of the others were light-water cooled and moderated, including the famous swimming-pool reactor that was copied dozens of times around the world. Two of the reactors were hoisted 200 feet into the air to study the shielding needs of proposed nuclear-powered aircraft. The final reactor, and the only one still operating today, is the High Flux Isotope Reactor (HFIR) that was built particularly for the production of californium and other heavy elements. With the world's highest flux and recent upgrades that include the addition of a cold neutron source, the 44-year-old HFIR continues to be a valuable tool for research and isotope production, attracting some 500 scientific visitors and guests to Oak Ridge each year. This report describes all of the reactors and their histories.

  4. Test and evaluation results of the /sup 252/Cf shuffler at the Savannah River Plant

    Energy Technology Data Exchange (ETDEWEB)

    Crane, T.W.

    1981-03-01

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

  5. Compensated bismuth-loaded plastic scintillators for neutron detection using low-energy pseudo-spectroscopy

    Science.gov (United States)

    Dumazert, Jonathan; Coulon, Romain; Bertrand, Guillaume H. V.; Normand, Stéphane; Méchin, Laurence; Hamel, Matthieu

    2016-05-01

    Gadolinium-covered modified plastic scintillators show a high potential for the deployment of cost-effective neutron detectors. Taking advantage of the low-energy photon and electron signature of thermal neutron captures in gadolinium-155 and gadolinium-157 however requires a background correction. In order to display a trustable rate, dual compensation schemes appear as an alternative to Pulse Shape Discrimination. This paper presents the application of such a compensation scheme to a two-bismuth loaded plastic scintillator system. A detection scintillator interacts with incident photon and fast neutron radiations and is covered with a gadolinium converter to become thermal neutron-sensitive as well. In the meantime, an identical compensation scintillator, covered with terbium, solely interacts with the photon and fast neutron part of incident radiations. After the acquisition and the treatment of the counting signals from both sensors, a hypothesis test determines whether the resulting count rate after subtraction falls into statistical fluctuations or provides a robust image of neutron activity. A laboratory prototype is tested under both photon and neutron radiations, allowing us to investigate the performance of the overall compensation system. The study reveals satisfactory results in terms of robustness to a cesium-137 background and in terms of sensitivity in presence of a californium-252 source.

  6. Measurement of neutron dose and spectra at light-water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Soldat, K.L.; Endres, G.W.R.; Cummings, F.M.

    1982-08-01

    In choosing one dosimeter over another, both sensitivity and precision must be addressed. It has been determined that dosimeters employing NTA film lack adequate sensitivity for use inside containment of nuclear plants. From this study, it is apparent that CR-39 and polycarbonate track etch films used without radiators are also inadequate. The rest of the dosimeters tested displayed adequate sensitivity. The two general types of dosimeters which comprise that group are: (1) TLDs and (2) the polycarbonate track etch which was used in conjunction with (n, ..cap alpha..) radiators. The precision of the TLD dosimeter depends on the calibration technique and response correction technique. TLD dosimeters calibrated to D/sub 2/O-moderated californium-252 or corrected based on 9- to 3-in. sphere response rates seemed to function best inside reactor containment. Polycarbonate track etch film with (n, ..cap alpha..) radiators was found to be sensitive enough for use inside reactor containment; however, the standard deviation for the results was roughly twice the value of the most precise TLD albedo dosimeters. Also, several of the polycarbonate dosimeters saturated, rendering any evaluation impossible.

  7. Report on the workshop "Decay spectroscopy at CARIBU: advanced fuel cycle applications, nuclear structure and astrophysics". 14-16 April 2011, Argonne National Laboratory, USA.

    Energy Technology Data Exchange (ETDEWEB)

    Kondev, F.; Carpenter, M.P.; Chowdhury, P.; Clark, J.A.; Lister, C.J.; Nichols, A.L.; Swewryniak, D. (Nuclear Engineering Division); (Univ. of Massachusetts); (Univ. of Surrey)

    2011-10-06

    A workshop on 'Decay Spectroscopy at CARIBU: Advanced Fuel Cycle Applications, Nuclear Structure and Astrophysics' will be held at Argonne National Laboratory on April 14-16, 2011. The aim of the workshop is to discuss opportunities for decay studies at the Californium Rare Isotope Breeder Upgrade (CARIBU) of the ATLAS facility with emphasis on advanced fuel cycle (AFC) applications, nuclear structure and astrophysics research. The workshop will consist of review and contributed talks. Presentations by members of the local groups, outlining the status of relevant in-house projects and availabile equipment, will also be organized. time will also be set aside to discuss and develop working collaborations for future decay studies at CARIBU. Topics of interest include: (1) Decay data of relevance to AFC applications with emphasis on reactor decay heat; (2) Discrete high-resolution gamma-ray spectroscopy following radioactive decya and related topics; (3) Calorimetric studies of neutron-rich fission framgents using Total ABsorption Gamma-Ray Spectrometry (TAGS) technique; (4) Beta-delayed neutron emissions and related topics; and (5) Decay data needs for nuclear astrophysics.

  8. Neutron activation determination of gold in technogenic raw materials with different mineral composition

    Directory of Open Access Journals (Sweden)

    Yudakov Aleksandr A.

    2015-01-01

    Full Text Available The methods used to determine the gold content in the technogenic objects of gold mining were analyzed regarding their non-homogeneity and complexity of chemical and mineral compositions. A possible application of the neutron activation analysis with the use of the californium source of neutrons for determining the content of fine-grained and extra-fine-grained gold in the technogenic objects, including the bottom-ash waste of energy providers, is considered. It was demonstrated that the chemical composition of the sample affects the neuron flux distribution in the sample, which can essentially distort the results of the neutron activation analysis. In order to eliminate possible systematic errors investigations of the effect of the sample mineral composition on the results of the gold determination using the neutron activation analysis were carried out. Namely, a large mass of rock (3-5 kg was loaded into an activation zone using four matrix types such as silicate, carbon-containing, iron-containing, and titanium magnetite. It was shown that there wereno significant difference between the dispersal of the fluxes of thermal and resonance neutrons emitted from 252Cf during activation of the gold-containing technogenic samples with different mineral compositions.

  9. On the use of a molten salt fast reactor to apply an idealized transmutation scenario for the nuclear phase out.

    Directory of Open Access Journals (Sweden)

    Bruno Merk

    Full Text Available In the view of transmutation of transuranium (TRU elements, molten salt fast reactors (MSFRs offer certain advantages compared to solid fuelled reactor types like sodium cooled fast reactors (SFRs. In the first part these advantages are discussed in comparison with the SFR technology, and the research challenges are analyzed. In the second part cycle studies for the MSFR are given for different configurations--a core with U-238 fertile, a fertile free core, and a core with Th-232 as fertile material. For all cases, the transmutation potential is determined and efficient transmutation performance for the case with thorium as a fertile material as well as for the fertile free case is demonstrated and the individual advantages are discussed. The time evolution of different important isotopes is analyzed. In the third part a strategy for the optimization of the transmutation efficiency is developed. The final aim is dictated by the phase out decision of the German government, which requests to put the focus on the determination of the maximal transmutation efficiency and on an as much as possible reduced leftover of transuranium elements at the end of the reactor life. This minimal leftover is achieved by a two step procedure of a first transmuter operation phase followed by a second deep burning phase. There the U-233, which is bred in the blanket of the core consisting of thorium containing salt, is used as feed. It is demonstrated, that transmutation rates up to more than 90% can be achieved for all transuranium isotopes, while the production of undesired high elements like californium is very limited. Additionally, the adaptations needed for the simulation of a MSFR, and the used tool HELIOS 1.10 is described.

  10. On the use of a molten salt fast reactor to apply an idealized transmutation scenario for the nuclear phase out.

    Science.gov (United States)

    Merk, Bruno; Rohde, Ulrich; Glivici-Cotruţă, Varvara; Litskevich, Dzianis; Scholl, Susanne

    2014-01-01

    In the view of transmutation of transuranium (TRU) elements, molten salt fast reactors (MSFRs) offer certain advantages compared to solid fuelled reactor types like sodium cooled fast reactors (SFRs). In the first part these advantages are discussed in comparison with the SFR technology, and the research challenges are analyzed. In the second part cycle studies for the MSFR are given for different configurations--a core with U-238 fertile, a fertile free core, and a core with Th-232 as fertile material. For all cases, the transmutation potential is determined and efficient transmutation performance for the case with thorium as a fertile material as well as for the fertile free case is demonstrated and the individual advantages are discussed. The time evolution of different important isotopes is analyzed. In the third part a strategy for the optimization of the transmutation efficiency is developed. The final aim is dictated by the phase out decision of the German government, which requests to put the focus on the determination of the maximal transmutation efficiency and on an as much as possible reduced leftover of transuranium elements at the end of the reactor life. This minimal leftover is achieved by a two step procedure of a first transmuter operation phase followed by a second deep burning phase. There the U-233, which is bred in the blanket of the core consisting of thorium containing salt, is used as feed. It is demonstrated, that transmutation rates up to more than 90% can be achieved for all transuranium isotopes, while the production of undesired high elements like californium is very limited. Additionally, the adaptations needed for the simulation of a MSFR, and the used tool HELIOS 1.10 is described.

  11. On the Use of a Molten Salt Fast Reactor to Apply an Idealized Transmutation Scenario for the Nuclear Phase Out

    Science.gov (United States)

    Merk, Bruno; Rohde, Ulrich; Glivici-Cotruţă, Varvara; Litskevich, Dzianis; Scholl, Susanne

    2014-01-01

    In the view of transmutation of transuranium (TRU) elements, molten salt fast reactors (MSFRs) offer certain advantages compared to solid fuelled reactor types like sodium cooled fast reactors (SFRs). In the first part these advantages are discussed in comparison with the SFR technology, and the research challenges are analyzed. In the second part cycle studies for the MSFR are given for different configurations – a core with U-238 fertile, a fertile free core, and a core with Th-232 as fertile material. For all cases, the transmutation potential is determined and efficient transmutation performance for the case with thorium as a fertile material as well as for the fertile free case is demonstrated and the individual advantages are discussed. The time evolution of different important isotopes is analyzed. In the third part a strategy for the optimization of the transmutation efficiency is developed. The final aim is dictated by the phase out decision of the German government, which requests to put the focus on the determination of the maximal transmutation efficiency and on an as much as possible reduced leftover of transuranium elements at the end of the reactor life. This minimal leftover is achieved by a two step procedure of a first transmuter operation phase followed by a second deep burning phase. There the U-233, which is bred in the blanket of the core consisting of thorium containing salt, is used as feed. It is demonstrated, that transmutation rates up to more than 90% can be achieved for all transuranium isotopes, while the production of undesired high elements like californium is very limited. Additionally, the adaptations needed for the simulation of a MSFR, and the used tool HELIOS 1.10 is described. PMID:24690768

  12. Production of medical radioisotopes in the ORNL high flux isotope reactor (HFIR) for cancer treatment and arterial restenosis therapy after PICA

    Science.gov (United States)

    Knapp, F. F.; Beets, A. L.; Mirzadeh, S.; Alexander, C. W.; Hobbs, R. L.

    1999-01-01

    The High Flux Isotope Reactor ( HFIR) at the Oak Ridge National Laboratory ( ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. First beginning operation in 1965, the high thermal neutron flux (2.5×1015 neutrons/cm2/sec at 85 MW) and versatile target irradiation and handling facilities provide the opportunity for production of a wide variety of neutron-rich medical radioisotopes of current interest for therapy. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117 m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube ( HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle (22-24 days) and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions ( PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117 m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed.

  13. a Theoretical Model of a Superheated Liquid Droplet Neutron Detector.

    Science.gov (United States)

    Harper, Mark Joseph

    from the polyenergetic spectra of bare and moderated californium spontaneous fission sources. The model's predicted response compared favorably with the experimental data.

  14. Blend Down Monitoring System Fissile Mass Flow Monitor Implementation at the ElectroChemical Plant, Zelenogorsk, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, T.

    2005-11-11

    The implementation plans and preparations for installation of the Fissile Mass Flow Monitor (FMFM) equipment at the ElectroChemical Plant (ECP), Zelenogorsk, Russia, are presented in this report. The FMFM, developed at Oak Ridge National Laboratory, is part of the Blend Down Monitoring System (BDMS), developed for the U.S. Department of Energy Highly Enriched Uranium (HEU) Transparency Implementation Program. The BDMS provides confidence to the United States that the Russian nuclear facilities supplying the lower-assay ({approx}4%) product low enriched uranium (P-LEU) to the United States from down-blended weapons-grade HEU are meeting the nonproliferation goals of the government-to-government HEU Purchase Agreement, signed between the Russian Federation and the United States in 1993. The first BDMS has been operational at Ural Electrochemical Integrated Plant, Novouralsk, since February 1999 and is successfully providing HEU transparency data to the United States. The second BDMS was installed at ECP in February 2003. The FMFM makes use of a set of thermalized californium-252 ({sup 252}Cf) spontaneous neutron sources for a modulated fission activation of the UF{sub 6} gas stream for measuring the {sup 235}U fissile mass flow rate. To do this, the FMFM measures the transport time of the fission fragments created from the fission activation process under the modulated source to the downstream detectors by detecting the delayed gamma rays from the fission fragments. The FMFM provides unattended, nonintrusive measurements of the {sup 235}U mass flow in the HEU, LEU blend stock, and P-LEU process legs. The FMFM also provides the traceability of the HEU flow to the product process leg. This report documents the technical installation requirements and the expected operational characteristics of the ECP FMFM.

  15. 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.

  16. Monte Carlo modeling and analyses of YALINA-booster subcritical assembly part 1: analytical models and main neutronics parameters.

    Energy Technology Data Exchange (ETDEWEB)

    Talamo, A.; Gohar, M. Y. A.; Nuclear Engineering Division

    2008-09-11

    This study was carried out to model and analyze the YALINA-Booster facility, of the Joint Institute for Power and Nuclear Research of Belarus, with the long term objective of advancing the utilization of accelerator driven systems for the incineration of nuclear waste. The YALINA-Booster facility is a subcritical assembly, driven by an external neutron source, which has been constructed to study the neutron physics and to develop and refine methodologies to control the operation of accelerator driven systems. The external neutron source consists of Californium-252 spontaneous fission neutrons, 2.45 MeV neutrons from Deuterium-Deuterium reactions, or 14.1 MeV neutrons from Deuterium-Tritium reactions. In the latter two cases a deuteron beam is used to generate the neutrons. This study is a part of the collaborative activity between Argonne National Laboratory (ANL) of USA and the Joint Institute for Power and Nuclear Research of Belarus. In addition, the International Atomic Energy Agency (IAEA) has a coordinated research project benchmarking and comparing the results of different numerical codes with the experimental data available from the YALINA-Booster facility and ANL has a leading role coordinating the IAEA activity. The YALINA-Booster facility has been modeled according to the benchmark specifications defined for the IAEA activity without any geometrical homogenization using the Monte Carlo codes MONK and MCNP/MCNPX/MCB. The MONK model perfectly matches the MCNP one. The computational analyses have been extended through the MCB code, which is an extension of the MCNP code with burnup capability because of its additional feature for analyzing source driven multiplying assemblies. The main neutronics parameters of the YALINA-Booster facility were calculated using these computer codes with different nuclear data libraries based on ENDF/B-VI-0, -6, JEF-2.2, and JEF-3.1.

  17. Monte Carlo modeling and analyses of YALINA booster subcritical assembly, Part III : low enriched uranium conversion analyses.

    Energy Technology Data Exchange (ETDEWEB)

    Talamo, A.; Gohar, Y. (Nuclear Engineering Division)

    2011-05-12

    This study investigates the performance of the YALINA Booster subcritical assembly, located in Belarus, during operation with high (90%), medium (36%), and low (21%) enriched uranium fuels in the assembly's fast zone. The YALINA Booster is a zero-power, subcritical assembly driven by a conventional neutron generator. It was constructed for the purpose of investigating the static and dynamic neutronics properties of accelerator driven subcritical systems, and to serve as a fast neutron source for investigating the properties of nuclear reactions, in particular transmutation reactions involving minor-actinides. The first part of this study analyzes the assembly's performance with several fuel types. The MCNPX and MONK Monte Carlo codes were used to determine effective and source neutron multiplication factors, effective delayed neutron fraction, prompt neutron lifetime, neutron flux profiles and spectra, and neutron reaction rates produced from the use of three neutron sources: californium, deuterium-deuterium, and deuterium-tritium. In the latter two cases, the external neutron source operates in pulsed mode. The results discussed in the first part of this report show that the use of low enriched fuel in the fast zone of the assembly diminishes neutron multiplication. Therefore, the discussion in the second part of the report focuses on finding alternative fuel loading configurations that enhance neutron multiplication while using low enriched uranium fuel. It was found that arranging the interface absorber between the fast and the thermal zones in a circular rather than a square array is an effective method of operating the YALINA Booster subcritical assembly without downgrading neutron multiplication relative to the original value obtained with the use of the high enriched uranium fuels in the fast zone.

  18. Questions to the radiological protection in the Universidad Nacional Autonoma de Mexico; Cuestionamientos a la proteccion radiologica en la Universidad Nacional Autonoma de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Salas M, B., E-mail: salasmarb@yahoo.com.mx [UNAM, Facultad de Ciencias, Departamento de Fisica, Circuito exterior s/n, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2014-08-15

    In the Physics Department of the Sciences Faculty of the Universidad Nacional Autonoma de Mexico (UNAM) exist at least 3 sites where radioactive sources and generating equipment s of ionizing radiation are managed: The Modern Physics Laboratory, the Radiological Analysis of Environmental Samples Workshop and the Collisions Workshop; the first of them has two neutron sources, in addition to other emitted sources of gamma and beta radiation. The neutron sources are of Americium 241-Beryllium and other of Californium-252 which have been operated outside of the control of the Comision Nacional de Seguridad Nuclear y Salvaguardias (CNSNS) that is the regulator organ in Mexico in nuclear matter, because the Operation License No. 183/85, with file number 657 that protected them, lost their validity from August 13, 1987 (25 years behind), what motivated to that the CNSNS assured them. Later to the closing of the Radiological Analysis of Environmental Samples Workshop was believed that a Barium-133 source had been extracted in an illegal way; an investigation realized by the CNSNS determined that the radioactive source was always inside of the detection systems and radiation measurement, for what this source was never lost. In the Collisions Workshop operated an Experimental Accelerator of Particles that the CNSNS prohibited its operation for not having the corresponding license. These examples can be considered as bad practices of radiological protection that should be pointed out to eradicate their promotion and to avoid this way the exposure to the radiation of the occupational exposed personnel and people in general, being also avoided dose of unnecessary radiation. The Instituto Federal de Acceso a la Informacion Publica y Proteccion de Datos (IFAI) in Mexico was a key factor to obtain the information that allowed the realization of this work that was carried out in the Sciences Faculty of the UNAM. (Author)

  19. Collecting high-order interactions in an effective pairwise intermolecular potential using the hydrated ion concept: The hydration of Cf{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Galbis, Elsa; Pappalardo, Rafael R.; Marcos, Enrique Sánchez, E-mail: sanchez@us.es [Departmento de Química Física, Universidad de Sevilla, 41012 Seville (Spain); Hernández-Cobos, Jorge [Instituto de Ciencias Físicas, UNAM, Apartado Postal 48-3, 62251 Cuernavaca (Mexico)

    2014-06-07

    This work proposes a new methodology to build interaction potentials between a highly charged metal cation and water molecules. These potentials, which can be used in classical computer simulations, have been fitted to reproduce quantum mechanical interaction energies (MP2 and BP86) for a wide range of [M(H{sub 2}O){sub n}]{sup m+}(H{sub 2}O){sub ℓ} clusters (n going from 6 to 10 and ℓ from 0 to 18). A flexible and polarizable water shell model (Mobile Charge Density of Harmonic Oscillator) has been coupled to the cation-water potential. The simultaneous consideration of poly-hydrated clusters and the polarizability of the interacting particles allows the inclusion of the most important many-body effects in the new polarizable potential. Applications have been centered on the californium, Cf(III) the heaviest actinoid experimentally studied in solution. Two different strategies to select a set of about 2000 structures which are used for the potential building were checked. Monte Carlo simulations of Cf(III)+500 H{sub 2}O for three of the intermolecular potentials predict an aquaion structure with coordination number close to 8 and average R{sub Cf−−O} in the range 2.43–2.48 Å, whereas the fourth one is closer to 9 with R{sub Cf−−O} = 2.54 Å. Simulated EXAFS spectra derived from the structural Monte Carlo distribution compares fairly well with the available experimental spectrum for the simulations bearing 8 water molecules. An angular distribution similar to that of a square antiprism is found for the octa-coordination.

  20. Charge breeding results and future prospects with electron cyclotron resonance ion source and electron beam ion source (invited).

    Science.gov (United States)

    Vondrasek, R; Levand, A; Pardo, R; Savard, G; Scott, R

    2012-02-01

    The Californium Rare Ion Breeder Upgrade (CARIBU) of the Argonne National Laboratory ATLAS facility will provide low-energy and reaccelerated neutron-rich radioactive beams for the nuclear physics program. A 70 mCi (252)Cf source produces fission fragments which are thermalized and collected by a helium gas catcher into a low-energy particle beam with a charge of 1+ or 2+. An electron cyclotron resonance (ECR) ion source functions as a charge breeder in order to raise the ion charge sufficiently for acceleration in the ATLAS linac. The final CARIBU configuration will utilize a 1 Ci (252)Cf source to produce radioactive beams with intensities up to 10(6) ions∕s for use in the ATLAS facility. The ECR charge breeder has been tested with stable beam injection and has achieved charge breeding efficiencies of 3.6% for (23)Na(8+), 15.6% for (84)Kr(17+), and 13.7% for (85)Rb(19+) with typical breeding times of 10 ms∕charge state. For the first radioactive beams, a charge breeding efficiency of 11.7% has been achieved for (143)Cs(27+) and 14.7% for (143)Ba(27+). The project has been commissioned with a radioactive beam of (143)Ba(27+) accelerated to 6.1 MeV∕u. In order to take advantage of its lower residual contamination, an EBIS charge breeder will replace the ECR charge breeder in the next two years. The advantages and disadvantages of the two techniques are compared taking into account the requirements of the next generation radioactive beam facilities.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-01

    The radioactive isotope Californium-252 (252Cf) is relied upon internationally as a neutron calibration source for ionizing radiation dosimetry because of its high specific activity. The source may be placed within a heavy-water (D2O) moderating sphere to produce a softened spectrum representative of neutron fields common to commercial nuclear power plant environments, among others. Due to termination of the U.S. Department of Energy loan/lease program in 2012, the expense of obtaining 252Cf sources has undergone a significant increase, rendering high output sources largely unattainable. On the other hand, the use of neutron generators in research and industry applications has increased dramatically in recent years. Neutron generators based on deuterium-tritium (D-T) fusion reaction provide high neutron fluence rates and, therefore, could possibly be used as a replacement for 252Cf. To be viable, the 14.6 MeV D-T output spectrum must be significantly moderated to approximate common workplace environments. This paper presents the results of an effort to select appropriate moderating materials and design a configuration to reshape the primary neutron field toward a spectrum approaching that from a nuclear power plant workplace. A series of Monte-Carlo (MCNP) simulations of single layer high- and low-Z materials are used to identify initial candidate moderators. Candidates are refined through a similar series of simulations involving combinations of 2 to 5 different materials. The simulated energy distribution using these candidate moderators are rated in comparison to a target spectrum. Other properties, such as fluence preservation and/or enhancement, prompt gamma production and other characteristics are also considered.

  2. Thermal Neutron Imaging Using A New Pad-Based Position Sensitive Neutron Detector

    Energy Technology Data Exchange (ETDEWEB)

    Dioszegi I.; Vanier P.E.; Salwen C.; Chichester D.L.; Watson S.M.

    2016-10-29

    Thermal neutrons (with mean energy of 25 meV) have a scattering mean free path of about 20 m in air. Therefore it is feasible to find localized thermal neutron sources up to ~30 m standoff distance using thermal neutron imaging. Coded aperture thermal neutron imaging was developed in our laboratory in the nineties, using He-3 filled wire chambers. Recently a new generation of coded-aperture neutron imagers has been developed. In the new design the ionization chamber has anode and cathode planes, where the anode is composed of an array of individual pads. The charge is collected on each of the individual 5x5 mm2 anode pads, (48x48 in total, corresponding to 24x24 cm2 sensitive area) and read out by application specific integrated circuits (ASICs). The high sensitivity of the ASICs allows unity gain operation mode. The new design has several advantages for field deployable imaging applications, compared to the previous generation of wire-grid based neutron detectors. Among these are the rugged design, lighter weight and use of non-flammable stopping gas. For standoff localization of thermalized neutron sources a low resolution (11x11 pixel) coded aperture mask has been fabricated. Using the new larger area detector and the coarse resolution mask we performed several standoff experiments using moderated californium and plutonium sources at Idaho National Laboratory. In this paper we will report on the development and performance of the new pad-based neutron camera, and present long range coded-aperture images of various thermalized neutron sources.

  3. Chemical properties of the heavier actinides and transactinides

    Energy Technology Data Exchange (ETDEWEB)

    Hulet, E.K.

    1981-01-01

    The chemical properties of each of the elements 99 (Es) through 105 are reviewed and their properties correlated with the electronic structure expected for 5f and 6d elements. A major feature of the heavier actinides, which differentiates them from the comparable lanthanides, is the increasing stability of the divalent oxidation state with increasing atomic number. The divalent oxidation state first becomes observable in the anhydrous halides of californium and increases in stability through the series to nobelium, where this valency becomes predominant in aqueous solution. In comparison with the analogous 4f electrons, the 5f electrons in the latter part of the series are more tightly bound. Thus, there is a lowering of the 5f energy levels with respect to the Fermi level as the atomic number increases. The metallic state of the heavier actinides has not been investigated except from the viewpoint of the relative volatility among members of the series. In aqueous solutions, ions of these elements behave as a normal trivalent actinides and lanthanides (except for nobelium). Their ionic radii decrease with increasing nuclear charge which is moderated because of increased screening of the outer 6p electrons by the 5f electrons. The actinide series of elements is completed with the element lawrencium (Lr) in which the electronic configuration is 5f/sup 14/7s/sup 2/7p. From Mendeleev's periodicity and Dirac-Fock calculations, the next group of elements is expected to be a d-transition series corresponding to the elements Hf through Hg. The chemical properties of elements 104 and 105 only have been studied and they indeed appear to show the properties expected of eka-Hf and eka-Ta. However, their nuclear lifetimes are so short and so few atoms can be produced that a rich variety of chemical information is probably unobtainable.

  4. Fabrication of uranium-based ceramics using internal gelation for the conversion of trivalent actinides; Herstellung uranbasierter Keramiken mittel interner Gelierung zur Konversion trivalenter Actinoiden

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, Henrik

    2012-07-01

    Alternative to today's direct final waste disposal strategy of long-lived radionuclides, for example the minor actinides neptunium, americium, curium and californium, is their selective separation from the radioactive wastestream with subsequent transmutation by neutron irradiation. Hereby it is possible to obtain nuclides with a lower risk-potential concerning their radiotoxicity. 1 neutron irradiation can be carried out either with neutron sources or in the next generation of nuclear reactors. Before the treatment, the minor actinides need to be converted in a suitable chemical and physical form. Internal gelation offers a route through which amorphous gel-spheres can be obtained directly from a metal-salt solution. Due to the presence of different types of metal ions as well as changing pH-values in a stock solution, a complex hydrolysis behaviour of these elements before and during gelation occurs. Therefore, investigations with uranium and neodymium as a minor actinide surrogate were carried out. As a result of suitable gelation-parameters, uraniumneodymium gel-spheres were successfully synthesised. The spheres also stayed intact during the subsequent thermal treatment. Based upon these findings, uranium-plutonium and uranium-americium gels were successfully created. For theses systems, the determined parameters for the uraniumneodymium gelation could also be applied. Additionally, investigations to reduce the acidity of uranium-based stock solutions for internal gelation were carried out. The necessary amount of urea and hexamethylenetetramine to induce gelation could hereby be decreased. This lead to a general increase of the gel quality and made it possible to carry out uranium-americium gelation in the first place. To investigate the stability of urea and hexamethylenetetramine, solutions of these chemicals were irradiated with different radiation doses. These chemicals showed a high stability against radiolysis in aqueous solutions.

  5. Effects of ISS equivalent ionizing radiation dose on Human T-lymphocytes

    Science.gov (United States)

    Meloni, Maria Antonia; Pani, Giuseppe; Benotmane, Rafi; Mastroleo, Felice; Aboul-El-Ardat, Khalil; Janssen, Ann; Leysen, Liselotte; Vanhavere, Filip; Leys, Natalie; Galleri, Grazia; Pippia, Proto; Baatout, Sarah

    One of the objectives of the current international space programs is to investigate the effects of cosmic environment on Humans. It is known that during a long exposure to the space conditions, including ionizing radiations and microgravity, the immune system of the astronauts is impaired. In past years several experiments were performed to identify responsible factors of in vitro mitogenic activation process in human T-lymphocytes under simulated microgravity effect and during dedicated space missions. It come out that the lack of immune response in microgravity occurs at the cellular and molecular level. In order to evaluate effects on pure primary T-lymphocytes from peripheral blood exposed to International Space Station (ISS)-like ionizing radiation, we applied a mixture of Cesium-137, as representative of low energy particles, and Californium-252, as representative of hight energy particles, with rate similar to those monitored inside the ISS during previous space mission (Goossens et all. 2006). This facility is available at SCK•CEN (Belgium) (Mastroleo et al., 2009). Although the dose received by the cells was relatively low, flow cytometry analysis 24 hours after irradiation showed a decrease in cell viability coupled with the increase of the caspase-3 activity. However, Bcl-2 activity did not seem to be affected by the radiation. Furthermore, activation of cells induced an increase of the cell size and alteration of cellular morphology. Cell cycle as well as 8-oxo-G were also modified upon radiation and activation. Gene expression analysis shows a modulation of genes rather as a consequence of exposure than with the activation status. 330 genes have been identified to be significantly modulated in function of the time and have been grouped in four different cluster representing significant expression profiles. Preliminary functional analysis shows mainly genes involved in the immune response and inflammatory diseases as well as oxidative stress and

  6. Robotics Use in Source Recovery at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, C.W.

    2001-01-10

    The Department of Energy's Savannah River Site (SRS) in Aiken South Carolina has a state of the art Instrument Calibrations facility that supports calibration and repair of an inventory of approximately 8000 portable radiological monitoring instruments. The Instrument Calibrations facility began operations in 1996. The Low Scatter Irradiator (LSI) system is a key part of the facility. The LSI room is a shielded 40-foot by 40-foot by 40-foot room designed to minimize radiation scatter during calibrations and evaluations. Aluminum floor grating with one-inch spacing is part of the design to minimize scatter. A shielded source storage carousel is used to select calibration sources via a computer-controlled system. The carousel has eight source slots with seven sources used providing a selection of 60Cobalt, 137Cesium, and 252Californium sources of different intensities. One slot is used for a dummy source for system function testing. Sources are contained in an aluminum container known as the source rabbit. Air pressure is used to blow the selected source through a transfer tube to the top of the tube where it is held in place by a suction cup and a maintained air vacuum. During calibrations, instruments are placed on four LSI tracks that move instruments to the proper distance from the source for the desired calibrated exposure rate. Sources are returned to the carousel using gravity with multiple interlocks and safeguards built into the system to ensure that the source has dropped before entry into the LSI after a source exposure. Two room radiation monitors provide a remote reading to the operator from the computer console as another indicator of the source status. Due to the design of the LSI, it was assumed that a source could not become lodged in the transfer tube. That proved to be a false assumption when in May 2000, a source did not return to its home position. At this time, the LSI was being tested due to some apparent difficulties in sources being held

  7. Detection limits for actinides in a monochromatic, wavelength-dispersive x-ray fluorescence instrument

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Michael L [Los Alamos National Laboratory; Havrilla, George J [Los Alamos National Laboratory

    2009-01-01

    Recent developments in x-ray optics have made it possible to examine the L x-rays of actinides using doubly-curved crystals in a bench-top device. A doubly-curved crystal (DCC) acts as a focusing monochromatic filter for polychromatic x-rays. A Monochromatic, Wavelength-Dispersive X-Ray Fluorescence (MWDXRF) instrument that uses DCCs to measure Cm and Pu in reprocessing plant liquors was proposed in 2007 by the authors at Los Alamos National Laboratory. A prototype design of this MWDXRF instrument was developed in collaboration with X-ray Optical Systems Inc. (XOS), of East Greenbush, New York. In the MWDXRF instrument, x-rays from a Rhodium-anode x-ray tube are passed through a primary DCC to produce a monochromatic beam of 20.2-keV photons. This beam is focused on a specimen that may contain actinides. The 20.2-keV interrogating beam is just above the L3 edge of Californium; each actinide (with Z = 90 to 98) present in the specimen emits characteristic L x-rays as the result of L3-shell vacancies. In the LANL-XOS prototype MWDXRf, these x-rays enter a secondary DCC optic that preferentially passes 14.961-keV photons, corresponding to the L-alpha-1 x-ray peak of Curium. In the present stage of experimentation, Curium-bearing specimens have not been analyzed with the prototype MWDXRF instrument. Surrogate materials for Curium include Rubidium, which has a K-beta-l x-ray at 14.961 keV, and Yttrium, which has a K-alpha-1 x-ray at 14.958 keV. In this paper, the lower limit of detection for Curium in the LANL-XOS prototype MWDXRF instrument is estimated. The basis for this estimate is described, including a description of computational models and benchmarking techniques used. Detection limits for other actinides are considered, as well as future safeguards applications for MWDXRF instrumentation.

  8. Benchmark Analysis of Subcritical Noise Measurements on a Nickel-Reflected Plutonium Metal Sphere

    Energy Technology Data Exchange (ETDEWEB)

    John D. Bess; Jesson Hutchinson

    2009-09-01

    Subcritical experiments using californium source-driven noise analysis (CSDNA) and Feynman variance-to-mean methods were performed with an alpha-phase plutonium sphere reflected by nickel shells, up to a maximum thickness of 7.62 cm. Both methods provide means of determining the subcritical multiplication of a system containing nuclear material. A benchmark analysis of the experiments was performed for inclusion in the 2010 edition of the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Benchmark models have been developed that represent these subcritical experiments. An analysis of the computed eigenvalues and the uncertainty in the experiment and methods was performed. The eigenvalues computed using the CSDNA method were very close to those calculated using MCNP5; however, computed eigenvalues are used in the analysis of the CSDNA method. Independent calculations using KENO-VI provided similar eigenvalues to those determined using the CSDNA method and MCNP5. A slight trend with increasing nickel-reflector thickness was seen when comparing MCNP5 and KENO-VI results. For the 1.27-cm-thick configuration the MCNP eigenvalue was approximately 300 pcm greater. The calculated KENO eigenvalue was about 300 pcm greater for the 7.62-cm-thick configuration. The calculated results were approximately the same for a 5-cm-thick shell. The eigenvalues determined using the Feynman method are up to approximately 2.5% lower than those determined using either the CSDNA method or the Monte Carlo codes. The uncertainty in the results from either method was not large enough to account for the bias between the two experimental methods. An ongoing investigation is being performed to assess what potential uncertainties and/or biases exist that have yet to be properly accounted for. The dominant uncertainty in the CSDNA analysis was the uncertainty in selecting a neutron cross-section library for performing the analysis of the data. The uncertainty in the

  9. Developments for transactinide chemistry experiments behind the gas-filled separator TASCA

    Energy Technology Data Exchange (ETDEWEB)

    Even, Julia

    2011-12-13

    Topic of this thesis is the development of experiments behind the gas-filled separator TASCA (TransActinide Separator and Chemistry Apparatus) to study the chemical properties of the transactinide elements. In the first part of the thesis, the electrodepositions of short-lived isotopes of ruthenium and osmium on gold electrodes were studied as model experiments for hassium. From literature it is known that the deposition potential of single atoms differs significantly from the potential predicted by the Nernst equation. This shift of the potential depends on the adsorption enthalpy of therndeposited element on the electrode material. If the adsorption on the electrode-material is favoured over the adsorption on a surface made of the same element as the deposited atom, the electrode potential is shifted to higher potentials. This phenomenon is called underpotential deposition. Possibilities to automatize an electro chemistry experiment behind the gas-filled separator were explored for later studies with transactinide elements. The second part of this thesis is about the in-situ synthesis of transition-metal-carbonyl complexes with nuclear reaction products. Fission products of uranium-235 and californium-249 were produced at the TRIGA Mainz reactor and thermalized in a carbon-monoxide containing atmosphere. The formed volatile metal-carbonyl complexes could be transported in a gas-stream. Furthermore, short-lived isotopes of tungsten, rhenium, osmium, and iridium were synthesised at the linear accelerator UNILAC at GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt. The recoiling fusion products were separated from the primary beam and the transfer products in the gas-filled separator TASCA. The fusion products were stopped in the focal plane of TASCA in a recoil transfer chamber. This chamber contained a carbon-monoxide - helium gas mixture. The formed metal-carbonyl complexes could be transported in a gas stream to various experimental setups. All

  10. 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

  11. Physics division annual report 2005.

    Energy Technology Data Exchange (ETDEWEB)

    Glover, J.; Physics

    2007-03-12

    This report highlights the research performed in 2005 in the Physics Division of Argonne National Laboratory. The Division's programs include operation of ATLAS as a national user facility, nuclear structure and reaction research, nuclear theory, medium energy nuclear research and accelerator research and development. The mission of Nuclear Physics is to understand the origin, evolution and structure of baryonic matter in the universe--the matter that makes up stars, planets and human life itself. The Division's research focuses on innovative new ways to address this mission and 2005 was a year of great progress. One of the most exciting developments is the initiation of the Californium Rare Ion Breeder Upgrade, CARIBU. By combining a Cf-252 fission source, the gas catcher technology developed for rare isotope beams, a high-resolution isobar separator, and charge breeding ECR technology, CARIBU will make hundreds of new neutron-rich isotope beams available for research. The cover illustration shows the anticipated intensities of low-energy beams that become available for low-energy experiments and for injection into ATLAS for reacceleration. CARIBU will be completed in early 2009 and provide us with considerable experience in many of the technologies developed for a future high intensity exotic beam facility. Notable results in research at ATLAS include a measurement of the isomeric states in {sup 252}No that helps pin down the single particle structure expected for superheavy elements, and a new low-background measurement of {sup 16}N beta-decay to determine the {sup 12}C({alpha},{gamma}){sup 16}O reaction rate that is so important in astrophysical environments. Precise mass measurements shed new light on the unitarity of the quark weak-mixing matrix in the search for physics beyond the standard model. ATLAS operated for 4686 hours of research in FY2005 while achieving 95% efficiency of beam delivery for experiments. In Medium-Energy Physics, radium

  12. NMIS with Imaging and Gamma Ray Spectrometry for Pu, HEU, HE and Other Materials

    Energy Technology Data Exchange (ETDEWEB)

    Mihalczo, John T [ORNL; Mullens, James Allen [ORNL

    2012-03-01

    imaging. The system is based on detection of transmitted 14.1 MeV neutrons, fission neutrons, and gamma rays from spontaneous, inherent source fission of the target, fission neutrons and gamma rays induced by the external DT source, gamma rays from natural emissions of uranium and plutonium, and induced gamma-ray emission by the interaction of the 14.1 MeV neutrons from the DT source. The NMIS can and has been used with a time-tagged californium spontaneous fission source. It has also been used with pulsed interrogation sources such as LINACs, DT, and deuterium-deuterium (DD) sources. This system is uniquely suited for detection of shielded highly enriched uranium (HEU), plutonium, and other special nuclear materials and detection of high explosives (HE) and chemical agents. The NMIS will be adapted to utilize a trusted processor that incorporates information barrier and authentication techniques using open software and then be useful in some international applications for materials whose characteristics may be classified. The proposed information barrier version of the NMIS system would consist of detectors and cables, the red (classified side) computer system, which processes the data, and the black (unclassified side) computer, which handles the computer interface. The system could use the 'IB wrapper' concept proposed by Los Alamos National Laboratory and the software integrity (digital signatures) system proposed by Sandia. Since it is based entirely on commercially available components, the entire system, including NMIS data acquisition boards, can be built with commercial off-the-shelf components. This system is being developed into a fieldable system (FNMIS) for potential arms control treaties by the ONV. The system will be modularly constructed with the RF shielded modules connected to the processor by appropriate control and signal cable in metal conduit. The FNMIS is presently being designed for eventual incorporation of gamma-ray spectrometry and an