Forensic neutron activation analysis

International Nuclear Information System (INIS)

Kishi, T.

1987-01-01

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

Physical basis for prompt-neutron activation analysis

International Nuclear Information System (INIS)

Chrien, R.E.

1982-01-01

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

Neutron activation analysis at the Californium User Facility for Neutron Science

International Nuclear Information System (INIS)

Martin, R.C.; Smith, E.H.; Glasgow, D.C.; Jerde, E.A.; Marsh, D.L.; Zhao, L.

1997-12-01

The Californium User Facility (CUF) for Neutron Science has been established to provide 252 Cf-based neutron irradiation services and research capabilities including neutron activation analysis (NAA). A major advantage of the CUF is its accessibility and controlled experimental conditions compared with those of a reactor environment The CUF maintains the world's largest inventory of compact 252 Cf neutron sources. Neutron source intensities of ≤ 10 11 neutrons/s are available for irradiations within a contamination-free hot cell, capable of providing thermal and fast neutron fluxes exceeding 10 8 cm -2 s -1 at the sample. Total flux of ≥10 9 cm -2 s -1 is feasible for large-volume irradiation rabbits within the 252 Cf storage pool. Neutron and gamma transport calculations have been performed using the Monte Carlo transport code MCNP to estimate irradiation fluxes available for sample activation within the hot cell and storage pool and to design and optimize a prompt gamma NAA (PGNAA) configuration for large sample volumes. Confirmatory NAA irradiations have been performed within the pool. Gamma spectroscopy capabilities including PGNAA are being established within the CUF for sample analysis

Neutron Activation Analysis with k0-standardisation

International Nuclear Information System (INIS)

Pomme, S.

2001-01-01

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

The synchronous active neutron detection assay system

International Nuclear Information System (INIS)

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

1994-01-01

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

Accurate measurements of neutron activation cross sections

International Nuclear Information System (INIS)

Semkova, V.

1999-01-01

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

Design considerations for neutron activation and neutron source strength monitors for ITER

International Nuclear Information System (INIS)

Barnes, C.W.; Jassby, D.L.; LeMunyan, G.; Roquemore, A.L.

1997-01-01

The International Thermonuclear Experimental Reactor will require highly accurate measurements of fusion power production in time, space, and energy. Spectrometers in the neutron camera could do it all, but experience has taught us that multiple methods with redundancy and complementary uncertainties are needed. Previously, conceptual designs have been presented for time-integrated neutron activation and time-dependent neutron source strength monitors, both of which will be important parts of the integrated suite of neutron diagnostics for this purpose. The primary goals of the neutron activation system are: to maintain a robust relative measure of fusion energy production with stability and wide dynamic range; to enable an accurate absolute calibration of fusion power using neutronic techniques as successfully demonstrated on JET and TFTR; and to provide a flexible system for materials testing. The greatest difficulty is that the irradiation locations need to be close to plasma with a wide field of view. The routing of the pneumatic system is difficult because of minimum radius of curvature requirements and because of the careful need for containment of the tritium and activated air. The neutron source strength system needs to provide real-time source strength vs. time with ∼1 ms resolution and wide dynamic range in a robust and reliable manner with the capability to be absolutely calibrated by in-situ neutron sources as done on TFTR, JT-60U, and JET. In this paper a more detailed look at the expected neutron flux field around ITER is folded into a more complete design of the fission chamber system

Proceedings of national seminar neutron activation analysis

International Nuclear Information System (INIS)

Agus Taftazani; Muhayatun Santoso; Budi Haryanto; Khatarina Oginawati

2010-11-01

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

Miniature neutron-alpha activation spectrometer

International Nuclear Information System (INIS)

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

2002-01-01

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

Fast neutron activation analysis in metallurgy

International Nuclear Information System (INIS)

Sterlinski, S.

1981-01-01

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

Neutron activation analysis

International Nuclear Information System (INIS)

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

2004-01-01

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

Calibration of neutron yield activation measurements at JET using MCNP and furnace neutron transport codes

International Nuclear Information System (INIS)

Pillon, M.; Martone, M.; Verschuur, K.A.; Jarvis, O.N.; Kaellne, J.

1989-01-01

Neutron transport calculations have been performed using fluence ray tracing (FURNACE code) and Monte Carlo particle trajectory sampling methods (MCNP code) in order to determine the neutron fluence and energy distributions at different locations in the JET tokamak. These calculations were used to calibrate the activation measurements used in the determination of the absolute fusion neutron yields from the JET plasma. We present here the neutron activation response coefficients calculated for three different materials. Comparison of the MCNP and FURNACE results helps identify the sources of error in these neutron transport calculations. The accuracy of these calculations was tested by comparing the total 2.5 MeV neutron yields derived from the activation measurements with those obtained with calibrated fission chambers; agreement at the ±15% level was demonstrate. (orig.)

Neutron Activation analysis of waste water

International Nuclear Information System (INIS)

Hernandez H, V.

1997-01-01

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

Neutron activation analysis (NAA), radioisotope production via neutron activation (PNA) and fission product gas-jet (GJA)

Energy Technology Data Exchange (ETDEWEB)

Gaeggeler, H W [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1996-11-01

Three different non-diffractive applications of neutrons are outlined, neutron activation analysis, production of radionuclides, mostly for medical applications, and production of short-lived fission nuclides with a so-called gas-jet. It is shown that all three devices may be incorporated into one single insert at SINQ due to their different requests with respect to thermal neutron flux. Some applications of these three facilities are summarized. (author) 3 figs., 1 tab., 8 refs.

Neutron activation analysis (NAA), radioisotope production via neutron activation (PNA) and fission product gas-jet (GJA)

International Nuclear Information System (INIS)

Gaeggeler, H.W.

1996-01-01

Three different non-diffractive applications of neutrons are outlined, neutron activation analysis, production of radionuclides, mostly for medical applications, and production of short-lived fission nuclides with a so-called gas-jet. It is shown that all three devices may be incorporated into one single insert at SINQ due to their different requests with respect to thermal neutron flux. Some applications of these three facilities are summarized. (author) 3 figs., 1 tab., 8 refs

The investigation of fast neutron Threshold Activation Detectors (TAD)

International Nuclear Information System (INIS)

Gozani, T; King, M J; Stevenson, J

2012-01-01

The detection of fast neutrons is usually done by liquid hydrogenous organic scintillators, where the separation between the ever present gamma rays and neutrons is achieved by the pulse shape discrimination (PSD). In many practical situation the detection of fast neutrons has to be carried out while the intense source (be it neutrons, gamma rays or x-rays) that creates these neutrons, for example by the fission process, is present. This source, or ''flash'', usually blinds the neutron detectors and temporarily incapacitates them. By the time the detectors recover the prompt neutron signature does not exist. Thus to overcome the blinding background, one needs to search for processes whereby the desired signature, such as fission neutrons could in some way be measured long after the fission occurred and when the neutron detector is fully recovered from the overload. A new approach was proposed and demonstrated a good sensitivity for the detection of fast neutrons in adverse overload situations where normally it could not be done. A temporal separation of the fission event from the prompt neutrons detection is achieved via the activation process. The main idea, called Threshold Activation Detection (or detector)-TAD, is to find appropriate substances that can be selectively activated by the fission neutrons and not by the source radiation, and then measure the radioactively decaying activation products (typically beta and γ-rays) well after the source pulse has ended. The activation material should possess certain properties: a suitable half-life; an energy threshold below which the numerous source neutrons will not activate it (e.g. about 3 MeV); easily detectable activation products and has a usable cross section for the selected reaction. Ideally the substance would be part of the scintillator. There are several good candidates for TAD. The first one we have selected is based on fluorine. One of the major advantages of this element is the fact that it is a major

The investigation of fast neutron Threshold Activation Detectors (TAD)

Science.gov (United States)

Gozani, T.; King, M. J.; Stevenson, J.

2012-02-01

The detection of fast neutrons is usually done by liquid hydrogenous organic scintillators, where the separation between the ever present gamma rays and neutrons is achieved by the pulse shape discrimination (PSD). In many practical situation the detection of fast neutrons has to be carried out while the intense source (be it neutrons, gamma rays or x-rays) that creates these neutrons, for example by the fission process, is present. This source, or ``flash'', usually blinds the neutron detectors and temporarily incapacitates them. By the time the detectors recover the prompt neutron signature does not exist. Thus to overcome the blinding background, one needs to search for processes whereby the desired signature, such as fission neutrons could in some way be measured long after the fission occurred and when the neutron detector is fully recovered from the overload. A new approach was proposed and demonstrated a good sensitivity for the detection of fast neutrons in adverse overload situations where normally it could not be done. A temporal separation of the fission event from the prompt neutrons detection is achieved via the activation process. The main idea, called Threshold Activation Detection (or detector)-TAD, is to find appropriate substances that can be selectively activated by the fission neutrons and not by the source radiation, and then measure the radioactively decaying activation products (typically beta and γ-rays) well after the source pulse has ended. The activation material should possess certain properties: a suitable half-life; an energy threshold below which the numerous source neutrons will not activate it (e.g. about 3 MeV); easily detectable activation products and has a usable cross section for the selected reaction. Ideally the substance would be part of the scintillator. There are several good candidates for TAD. The first one we have selected is based on fluorine. One of the major advantages of this element is the fact that it is a major

Analysis of coal by neutron activation

International Nuclear Information System (INIS)

Burtner, D.R.

1983-01-01

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

Neutron activation analysis of geochemical samples

International Nuclear Information System (INIS)

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

1983-06-01

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

Nondestructive neutron activation analysis of silicon carbide

Energy Technology Data Exchange (ETDEWEB)

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

1973-10-15

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

Activation measurements for fast neutrons. Part A. Sulfur (32P) activation

International Nuclear Information System (INIS)

Kerr, George D.

2005-01-01

The sulfur activation measurements at Hiroshima have been useful in refining and verifying the neutron source-term calculations for the Hiroshima bomb (Kerr and Pace 1988). For example, the Riken measurements of sulfur activation at Hiroshima were used to demonstrate that a two dimensional calculation of the neutron leakage was required for the Hiroshima bomb in order to accurately account for the blind spot in the neutron leakage through the nose of the device (Kerr 1982a,b; Kerr et al. 1983; Pace and Kerr 1984). The sulfur activation measurements at Hiroshima are discussed and compared in this section with the results of DS86 and DS02 calculations for the air-over-ground transport of neutrons at Hiroshima. (J.P.N.)

Prompt gamma neutron activation analysis

International Nuclear Information System (INIS)

Goswami, A.

2003-01-01

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

Determination of phosphorus using derivative neutron activation

International Nuclear Information System (INIS)

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

2002-01-01

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

Miniature Neutron-Alpha Activation Spectrometer

Science.gov (United States)

Rhodes, E.; Goldsten, J.

2001-01-01

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

Methodological developments and applications of neutron activation analysis

International Nuclear Information System (INIS)

Kucera, J.

2007-01-01

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

Computer-automated neutron activation analysis system

International Nuclear Information System (INIS)

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

1983-01-01

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

Neutron activation system for spectral measurements of pulsed ion diode neutron production

International Nuclear Information System (INIS)

Hanson, D.L.; Kruse, L.W.

1980-02-01

A neutron energy spectrometer has been developed to study intense ion beam-target interactions in the harsh radiation environment of a relativistic electron beam source. The main component is a neutron threshold activation system employing two multiplexed high efficiency Ge(Li) detectors, an annihilation gamma coincidence system, and a pneumatic sample transport. Additional constraints on the neutron spectrum are provided by total neutron yield and time-of-flight measurements. A practical lower limit on the total neutron yield into 4π required for a spectral measurement with this system is approx. 10 10 n where the neutron yield is predominantly below 4 MeV and approx. 10 8 n when a significant fraction of the yield is above 4 MeV. Applications of this system to pulsed ion diode neutron production experiments on Hermes II are described

Neutron activation analysis: Modelling studies to improve the neutron flux of Americium-Beryllium source

Energy Technology Data Exchange (ETDEWEB)

Didi, Abdessamad; Dadouch, Ahmed; Tajmouati, Jaouad; Bekkouri, Hassane [Advanced Technology and Integration System, Dept. of Physics, Faculty of Science Dhar Mehraz, University Sidi Mohamed Ben Abdellah, Fez (Morocco); Jai, Otman [Laboratory of Radiation and Nuclear Systems, Dept. of Physics, Faculty of Sciences, Tetouan (Morocco)

2017-06-15

Americium–beryllium (Am-Be; n, γ) is a neutron emitting source used in various research fields such as chemistry, physics, geology, archaeology, medicine, and environmental monitoring, as well as in the forensic sciences. It is a mobile source of neutron activity (20 Ci), yielding a small thermal neutron flux that is water moderated. The aim of this study is to develop a model to increase the neutron thermal flux of a source such as Am-Be. This study achieved multiple advantageous results: primarily, it will help us perform neutron activation analysis. Next, it will give us the opportunity to produce radio-elements with short half-lives. Am-Be single and multisource (5 sources) experiments were performed within an irradiation facility with a paraffin moderator. The resulting models mainly increase the thermal neutron flux compared to the traditional method with water moderator.

A review of conventional explosives detection using active neutron interrogation

International Nuclear Information System (INIS)

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

2014-01-01

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

Neutron activation determination of impurities in molybdenum

International Nuclear Information System (INIS)

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

1984-01-01

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

Measurements of DT and DD neutron yields by neutron activation on TFTR

International Nuclear Information System (INIS)

Barnes, C.W.; Larson, A.R.; LeMunyan, G.

1994-01-01

A variety of elemental foils have been activated by neutron fluence from TFTR under conditions with the DT neutron yield per shot ranging from 10 12 to over 10 18 , and with the DT/(DD+DT) neutron ratio varying from 0.5% (from triton burnup) to unity. Linear response over this large dynamic range is obtained by reducing the mass of the foils and increasing the cooling time, all while accepting greatly improved counting statistics. Effects on background gamma-ray lines from foil-capsule-material contaminants. and the resulting lower limits on activation foil mass, have been determined. DT neutron yields from dosimetry standard reactions on aluminum, chromium, iron, nickel, zirconium, and indium are in agreement within the ±9% (one-sigma,) accuracy of the measurements: also agreeing are yields from silicon foils using the ACTL library cross-section. While the ENDF/B-V library has too low a cross-section. Preliminary results from a variety of other threshold reactions are presented. Use of the 115 In(n,n) 115m In reaction (0.42 times as sensitive to DT neutrons as DD neutrons) in conjunction with pure-DT reactions allows a determination of the DT/(DD+DT) ratio in trace tritium or low-power tritium beam experiments

Measurements of DT and DD neutron yields by neutron activation on TFTR

International Nuclear Information System (INIS)

Barnes, C.W.; Larson, A.R.; LeMunyan, G.

1995-03-01

A variety of elemental foils have been activated by neutron fluence from TFTR under conditions with the DT neutron yield per shot ranging from 10 12 to over 10 18 , and with the DT/(DD+DT) neutron ratio varying from 0.5% (from triton burnup) to unity. Linear response over this large dynamic range is obtained by reducing the mass of the foils and increasing the cooling time, all while accepting greatly improved counting statistics. Effects on background gamma-ray lines from foil-capsule-material contaminants, and the resulting lower limits on activation foil mass, have been determined. DT neutron yields from dosimetry standard reactions on aluminum, chromium, iron, nickel, zirconium, and indium are in agreement within the ±9% (one-sigma) accuracy of the measurements; also agreeing are yields from silicon foils using the ACTL library cross-section, while the ENDF/B-V library has too low a cross-section. Preliminary results from a variety of other threshold reactions are presented. Use of the 115 In(n.n') 115m In reaction (0.42 times as sensitive to DT neutrons as DD neutrons) in conjunction with pure-DT reactions allows a determination of the DT/(DD+DT) ratio in trace tritium or low-power tritium beam experiments

Neutron activation analysis: principle and methods

International Nuclear Information System (INIS)

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

2006-01-01

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

Pulsed neutron generator for mass flow measurement using the pulsed neutron activation technique

International Nuclear Information System (INIS)

Rochau, G.E.; Hornsby, D.R.; Mareda, J.F.; Riggan, W.C.

1980-01-01

A high-output, transportable neutron generator has been developed to measure mass flow velocities in reactor safety tests using the Pulsed Neutron Activation (PNA) Technique. The PNA generator produces >10 10 14 MeV D-T neutrons in a 1.2 millisecond pulse. The Millisecond Pulse (MSP) Neutron Tube, developed for this application, has an expected operational life of 1000 pulses, and it limits the generator pulse repetition rate to 12 pulses/minute. A semiconductor neutron detector is included in the generator package to monitor the neutron output. The control unit, which can be operated manually or remotely, also contains a digital display with a BCD output for the neutron monitor information. The digital logic of the unit controls the safety interlocks and rejects transient signals which could accidently fire the generator

Pulsed neutron activation calibration technique

International Nuclear Information System (INIS)

Kehler, P.

1979-01-01

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

Thermal neutron self-shielding correction factors for large sample instrumental neutron activation analysis using the MCNP code

International Nuclear Information System (INIS)

Tzika, F.; Stamatelatos, I.E.

2004-01-01

Thermal neutron self-shielding within large samples was studied using the Monte Carlo neutron transport code MCNP. The code enabled a three-dimensional modeling of the actual source and geometry configuration including reactor core, graphite pile and sample. Neutron flux self-shielding correction factors derived for a set of materials of interest for large sample neutron activation analysis are presented and evaluated. Simulations were experimentally verified by measurements performed using activation foils. The results of this study can be applied in order to determine neutron self-shielding factors of unknown samples from the thermal neutron fluxes measured at the surface of the sample

In vivo neutron activation facility at Brookhaven National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Ma, R.; Yasumura, Seiichi; Dilmanian, F.A.

1997-11-01

Seven important body elements, C, N, Ca, P, K, Na, and Cl, can be measured with great precision and accuracy in the in vivo neutron activation facilities at Brookhaven National Laboratory. The facilities include the delayed-gamma neutron activation, the prompt-gamma neutron activation, and the inelastic neutron scattering systems. In conjunction with measurements of total body water by the tritiated-water dilution method several body compartments can be defined from the contents of these elements, also with high precision. In particular, body fat mass is derived from total body carbon together with total body calcium and nitrogen; body protein mass is derived from total body nitrogen; extracellular fluid volume is derived from total body sodium and chlorine; lean body mass and body cell mass are derived from total body potassium; and, skeletal mass is derived from total body calcium. Thus, we suggest that neutron activation analysis may be valuable for calibrating some of the instruments routinely used in clinical studies of body composition. The instruments that would benefit from absolute calibration against neutron activation analysis are bioelectric impedance analysis, infrared interactance, transmission ultrasound, and dual energy x-ray/photon absorptiometry.

A neutron irradiator to perform nuclear activation

International Nuclear Information System (INIS)

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

2001-01-01

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

Calibration of the delayed-gamma neutron activation facility

International Nuclear Information System (INIS)

Ma, R.; Zhao, X.; Rarback, H.M.; Yasumura, S.; Dilmanian, F.A.; Moore, R.I.; Lo Monte, A.F.; Vodopia, K.A.; Liu, H.B.; Economos, C.D.; Nelson, M.E.; Aloia, J.F.; Vaswani, A.N.; Weber, D.A.; Pierson, R.N. Jr.; Joel, D.D.

1996-01-01

The delayed-gamma neutron activation facility at Brookhaven National Laboratory was originally calibrated using an anthropomorphic hollow phantom filled with solutions containing predetermined amounts of Ca. However, 99% of the total Ca in the human body is not homogeneously distributed but contained within the skeleton. Recently, an artificial skeleton was designed, constructed, and placed in a bottle phantom to better represent the Ca distribution in the human body. Neutron activation measurements of an anthropomorphic and a bottle (with no skeleton) phantom demonstrate that the difference in size and shape between the two phantoms changes the total body calcium results by less than 1%. To test the artificial skeleton, two small polyethylene jerry-can phantoms were made, one with a femur from a cadaver and one with an artificial bone in exactly the same geometry. The femur was ashed following the neutron activation measurements for chemical analysis of Ca. Results indicate that the artificial bone closely simulates the real bone in neutron activation analysis and provides accurate calibration for Ca measurements. Therefore, the calibration of the delayed-gamma neutron activation system is now based on the new bottle phantom containing an artificial skeleton. This change has improved the accuracy of measurement for total body calcium. Also, the simple geometry of this phantom and the artificial skeleton allows us to simulate the neutron activation process using a Monte Carlo code, which enables us to calibrate the system for human subjects larger and smaller than the phantoms used as standards. copyright 1996 American Association of Physicists in Medicine

Neutron activation analysis: Modelling studies to improve the neutron flux of Americium–Beryllium source

Directory of Open Access Journals (Sweden)

Abdessamad Didi

2017-06-01

Full Text Available Americium–beryllium (Am-Be; n, γ is a neutron emitting source used in various research fields such as chemistry, physics, geology, archaeology, medicine, and environmental monitoring, as well as in the forensic sciences. It is a mobile source of neutron activity (20 Ci, yielding a small thermal neutron flux that is water moderated. The aim of this study is to develop a model to increase the neutron thermal flux of a source such as Am-Be. This study achieved multiple advantageous results: primarily, it will help us perform neutron activation analysis. Next, it will give us the opportunity to produce radio-elements with short half-lives. Am-Be single and multisource (5 sources experiments were performed within an irradiation facility with a paraffin moderator. The resulting models mainly increase the thermal neutron flux compared to the traditional method with water moderator.

Monte Carlo method in neutron activation analysis

International Nuclear Information System (INIS)

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

2009-01-01

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

Neutron activation analysis in Bulgaria

International Nuclear Information System (INIS)

Apostolov, D.

1985-01-01

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

New experimental research stand SVICKA neutron field analysis using neutron activation detector technique

Science.gov (United States)

Varmuza, Jan; Katovsky, Karel; Zeman, Miroslav; Stastny, Ondrej; Haysak, Ivan; Holomb, Robert

2018-04-01

Knowledge of neutron energy spectra is very important because neutrons with various energies have a different material impact or a biological tissue impact. This paper presents basic results of the neutron flux distribution inside the new experimental research stand SVICKA which is located at Brno University of Technology in Brno, Czech Republic. The experiment also focused on the investigation of the sandwich biological shielding quality that protects staff against radiation effects. The set of indium activation detectors was used to the investigation of neutron flux distribution. The results of the measurement provide basic information about the neutron flux distribution inside all irradiation channels and no damage or cracks are present in the experimental research stand biological shielding.

Fast neutron activation analysis of Kalewa (Myanmar) coal

Energy Technology Data Exchange (ETDEWEB)

Myint, U; Naing, W [Yangon Univ. (Myanmar). Dept. of Chemistry

1994-06-01

Aluminium, silicon, copper, iron, magnesium and sulfur in Kalewa (Myanmar) coal were determined by fast neutron activation analysis. For activation a KAMAN A-710 Neutron Generator was used. Kalewa coal was found to be low in sulfur and relatively rich in iron. (author) 2 refs.; 1 fig.; 1 tab.

Fast neutron activation analysis of Kalewa (Myanmar) coal

International Nuclear Information System (INIS)

Myint, U.; Naing, W.

1994-01-01

Aluminium, silicon, copper, iron, magnesium and sulfur in Kalewa (Myanmar) coal were determined by fast neutron activation analysis. For activation a KAMAN A-710 Neutron Generator was used. Kalewa coal was found to be low in sulfur and relatively rich in iron. (author) 2 refs.; 1 fig.; 1 tab

Neutron threshold activation detectors (TAD) for the detection of fissions

Science.gov (United States)

Gozani, Tsahi; Stevenson, John; King, Michael J.

2011-10-01

Prompt fission neutrons are one of the strongest signatures of the fission process. Depending on the fission inducing radiation, their average number ranges from 2.5 to 4 neutrons per fission. They are more energetic and abundant, by about 2 orders of magnitude, than the delayed neutrons (≈3 vs. ≈0.01) that are commonly used as indicators for the presence of fissionable materials. The detection of fission prompt neutrons, however, has to be done in the presence of extremely intense probing radiation that stimulated them. During irradiation, the fission stimulation radiation, X-rays or neutrons, overwhelms the neutron detectors and temporarily incapacitate them. Consequently, by the time the detectors recover from the source radiation, fission prompt neutrons are no longer emitted. In order to measure the prompt fission signatures under these circumstances, special measures are usually taken with the detectors such as heavy shielding with collimation, use of inefficient geometries, high pulse height bias and gamma-neutron separation via pulse-shape discrimination with an appropriate organic scintillator. These attempts to shield the detector from the flash of radiation result in a major loss of sensitivity. It can lead to a complete inability to detect the fission prompt neutrons. In order to overcome the blinding induced background from the source radiation, the detection of prompt fission neutrons needs to occur long after the fission event and after the detector has fully recovered from the source overload. A new approach to achieve this is to detect the delayed activation induced by the fission neutrons. The approach demonstrates a good sensitivity in adverse overload situations (gamma and neutron "flash") where fission prompt neutrons could normally not be detected. The new approach achieves the required temporal separation between the detection of prompt neutrons and the detector overload by the neutron activation of the detector material. The technique

Neutron threshold activation detectors (TAD) for the detection of fissions

International Nuclear Information System (INIS)

Gozani, Tsahi; Stevenson, John; King, Michael J.

2011-01-01

Prompt fission neutrons are one of the strongest signatures of the fission process. Depending on the fission inducing radiation, their average number ranges from 2.5 to 4 neutrons per fission. They are more energetic and abundant, by about 2 orders of magnitude, than the delayed neutrons (∼3 vs. ∼0.01) that are commonly used as indicators for the presence of fissionable materials. The detection of fission prompt neutrons, however, has to be done in the presence of extremely intense probing radiation that stimulated them. During irradiation, the fission stimulation radiation, X-rays or neutrons, overwhelms the neutron detectors and temporarily incapacitate them. Consequently, by the time the detectors recover from the source radiation, fission prompt neutrons are no longer emitted. In order to measure the prompt fission signatures under these circumstances, special measures are usually taken with the detectors such as heavy shielding with collimation, use of inefficient geometries, high pulse height bias and gamma-neutron separation via pulse-shape discrimination with an appropriate organic scintillator. These attempts to shield the detector from the flash of radiation result in a major loss of sensitivity. It can lead to a complete inability to detect the fission prompt neutrons. In order to overcome the blinding induced background from the source radiation, the detection of prompt fission neutrons needs to occur long after the fission event and after the detector has fully recovered from the source overload. A new approach to achieve this is to detect the delayed activation induced by the fission neutrons. The approach demonstrates a good sensitivity in adverse overload situations (gamma and neutron 'flash') where fission prompt neutrons could normally not be detected. The new approach achieves the required temporal separation between the detection of prompt neutrons and the detector overload by the neutron activation of the detector material. The technique

Neutron threshold activation detectors (TAD) for the detection of fissions

Energy Technology Data Exchange (ETDEWEB)

Gozani, Tsahi, E-mail: tgozani@rapiscansystems.com [Rapiscan Laboratories, Inc., 520 Almanor Ave., Sunnyvale, CA 94085 (United States); Stevenson, John; King, Michael J. [Rapiscan Laboratories, Inc., 520 Almanor Ave., Sunnyvale, CA 94085 (United States)

2011-10-01

Prompt fission neutrons are one of the strongest signatures of the fission process. Depending on the fission inducing radiation, their average number ranges from 2.5 to 4 neutrons per fission. They are more energetic and abundant, by about 2 orders of magnitude, than the delayed neutrons ({approx}3 vs. {approx}0.01) that are commonly used as indicators for the presence of fissionable materials. The detection of fission prompt neutrons, however, has to be done in the presence of extremely intense probing radiation that stimulated them. During irradiation, the fission stimulation radiation, X-rays or neutrons, overwhelms the neutron detectors and temporarily incapacitate them. Consequently, by the time the detectors recover from the source radiation, fission prompt neutrons are no longer emitted. In order to measure the prompt fission signatures under these circumstances, special measures are usually taken with the detectors such as heavy shielding with collimation, use of inefficient geometries, high pulse height bias and gamma-neutron separation via pulse-shape discrimination with an appropriate organic scintillator. These attempts to shield the detector from the flash of radiation result in a major loss of sensitivity. It can lead to a complete inability to detect the fission prompt neutrons. In order to overcome the blinding induced background from the source radiation, the detection of prompt fission neutrons needs to occur long after the fission event and after the detector has fully recovered from the source overload. A new approach to achieve this is to detect the delayed activation induced by the fission neutrons. The approach demonstrates a good sensitivity in adverse overload situations (gamma and neutron 'flash') where fission prompt neutrons could normally not be detected. The new approach achieves the required temporal separation between the detection of prompt neutrons and the detector overload by the neutron activation of the detector

Fast neutron activation analysis

International Nuclear Information System (INIS)

Pepelnik, R.

1986-01-01

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

Activation measurements for thermal neutrons. Part J. Evaluation of thermal neutron transmission factors

International Nuclear Information System (INIS)

Egbert, Stephen D.

2005-01-01

In order to relate thermal neutron activation measurements in samples to the calculated free-in-air thermal neutron activation levels given in Chapter 3, use is made of sample transmission factors. Transmission factors account for the modification of the fluence and activation at each sample's in situ location. For the purposes of this discussion, the transmission factor (TF) is defined as the ratio of the in situ sample activation divided by the free-in-air (FIA) activation at a height of 1 m above ground at the same ground range. The procedures for calculation of TF's and example results are presented in this section. (author)

Novel fast-neutron activation counter for high repetition rate measurements

International Nuclear Information System (INIS)

Mahmood, S.; Springham, S. V.; Zhang, T.; Rawat, R. S.; Tan, T. L.; Krishnan, M.; Beg, F. N.; Lee, S.; Schmidt, H.; Lee, P.

2006-01-01

A fast-neutron beryllium activation counter has been constructed for neutron measurements on a high repetition rate deuterium plasma focus. Beryllium activation is especially suitable for measurements of DD neutron yields. The cross section for the relevant reaction, 9 Be(n,α) 6 He, results in a maximum sensitivity at the characteristic energy of the DD neutrons (∼2.5 MeV) and practically no sensitivity to neutrons with energies 6 He enabled the shot-to-shot neutron yield from the plasma focus to be measured for repetition rates from 0.2 to 3 Hz (and for a range of deuterium gas pressures). With careful analysis, the shot-to-shot yield can be measured up to a maximum repetition rate of 3 Hz, beyond which the pileup of counts from the previous shots reduces the accuracy of the measurements to an unacceptable level. This new beryllium activation counter has been cross-checked against an indium activation counter to obtain absolute neutron yields. At a charging voltage of 12.5 kV (bank energy of 2.2 kJ), the average neutron yield was found to be (7.9±0.7)x10 7 per shot (standard deviation of 4x10 7 ). It was found that activation of the plasma focus construction materials (especially aluminum) must be taken into account

Monte Carlo calculations and neutron spectrometry in quantitative prompt gamma neutron activation analysis (PGNAA) of bulk samples using an isotopic neutron source

International Nuclear Information System (INIS)

Spyrou, N.M.; Awotwi-Pratt, J.B.; Williams, A.M.

2004-01-01

An activation analysis facility based on an isotopic neutron source (185 GBq 241 Am/Be) which can perform both prompt and cyclic activation analysis on bulk samples, has been used for more than 20 years in many applications including 'in vivo' activation analysis and the determination of the composition of bio-environmental samples, such as, landfill waste and coal. Although the comparator method is often employed, because of the variety in shape, size and elemental composition of these bulk samples, it is often difficult and time consuming to construct appropriate comparator samples for reference. One of the obvious problems is the distribution and energy of the neutron flux in these bulk and comparator samples. In recent years, it was attempted to adopt the absolute method based on a monostandard and to make calculations using a Monte Carlo code (MCNP4C2) to explore this further. In particular, a model of the irradiation facility has been made using the MCNP4C2 code in order to investigate the factors contributing to the quantitative determination of the elemental concentrations through prompt gamma neutron activation analysis (PGNAA) and most importantly, to estimate how the neutron energy spectrum and neutron dose vary with penetration depth into the sample. This simulation is compared against the scattered and transmitted neutron energy spectra that are experimentally and empirically determined using a portable neutron spectrometry system. (author)

Development of a new deuterium-deuterium (D-D) neutron generator for prompt gamma-ray neutron activation analysis.

Science.gov (United States)

Bergaoui, K; Reguigui, N; Gary, C K; Brown, C; Cremer, J T; Vainionpaa, J H; Piestrup, M A

2014-12-01

A new deuterium-deuterium (D-D) neutron generator has been developed by Adelphi Technology for prompt gamma neutron activation analysis (PGNAA), neutron activation analysis (NAA), and fast neutron radiography. The generator makes an excellent fast, intermediate, and thermal neutron source for laboratories and industrial applications that require the safe production of neutrons, a small footprint, low cost, and small regulatory burden. The generator has three major components: a Radio Frequency Induction Ion Source, a Secondary Electron Shroud, and a Diode Accelerator Structure and Target. Monoenergetic neutrons (2.5MeV) are produced with a yield of 10(10)n/s using 25-50mA of deuterium ion beam current and 125kV of acceleration voltage. The present study characterizes the performance of the neutron generator with respect to neutron yield, neutron production efficiency, and the ionic current as a function of the acceleration voltage at various RF powers. In addition the Monte Carlo N-Particle Transport (MCNP) simulation code was used to optimize the setup with respect to thermal flux and radiation protection. Copyright © 2014 Elsevier Ltd. All rights reserved.

Applications of neutrons for laboratory and industrial activation analysis problems

International Nuclear Information System (INIS)

Szabo, Elek; Bakos, Laszlo

1986-01-01

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

Forensic neutron activation analysis - the Japanese scene

International Nuclear Information System (INIS)

Kishi, Tohru.

1986-01-01

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

Particulate matter and neutron activation analysis

International Nuclear Information System (INIS)

Otoshi, Tsunehiko

2003-01-01

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

Beryllium neutron activation detector for pulsed DD fusion sources

International Nuclear Information System (INIS)

Talebitaher, A.; Springham, S.V.; Rawat, R.S.; Lee, P.

2011-01-01

A compact fast neutron detector based on beryllium activation has been developed to perform accurate neutron fluence measurements on pulsed DD fusion sources. It is especially well suited to moderate repetition-rate ( 9 Be(n,α) 6 He cross-section, energy calibration of the proportional counters, and numerical simulations of neutron interactions and beta-particle paths using MCNP5. The response function R(E n ) is determined over the neutron energy range 2-4 MeV. The count rate capability of the detector has been studied and the corrections required for high neutron fluence measurements are discussed. For pulsed DD neutron fluencies >3×10 4 cm -2 , the statistical uncertainty in the fluence measurement is better than 1%. A small plasma focus device has been employed as a pulsed neutron source to test two of these new detectors, and their responses are found to be practically identical. Also the level of interfering activation is found to be sufficiently low as to be negligible.

The gut microbiome restores intrinsic and extrinsic nerve function in germ-free mice accompanied by changes in calbindin.

Science.gov (United States)

McVey Neufeld, K A; Perez-Burgos, A; Mao, Y K; Bienenstock, J; Kunze, W A

2015-05-01

The microbiome is essential for normal myenteric intrinsic primary afferent neuron (IPAN) excitability. These neurons control gut motility and modulate gut-brain signaling by exciting extrinsic afferent fibers innervating the enteric nervous system via an IPAN to extrinsic fiber sensory synapse. We investigated effects of germ-free (GF) status and conventionalization on extrinsic sensory fiber discharge in the mesenteric nerve bundle and IPAN electrophysiology, and compared these findings with those from specific pathogen-free (SPF) mice. As we have previously shown that the IPAN calcium-dependent slow afterhyperpolarization (sAHP) is enhanced in GF mice, we also examined the expression of the calcium-binding protein calbindin in these neurons in these different animal groups. IPAN sAHP and mesenteric nerve multiunit discharge were recorded using ex vivo jejunal gut segments from SPF, GF, or conventionalized (CONV) mice. IPANs were excited by adding 5 μM TRAM-34 to the serosal superfusate. We probed for calbindin expression using immunohistochemical techniques. SPF mice had a 21% increase in mesenteric nerve multiunit firing rate and CONV mice a 41% increase when IPANs were excited by TRAM-34. For GF mice, this increase was barely detectable (2%). TRAM-34 changed sAHP area under the curve by -77 for SPF, +3 for GF, or -54% for CONV animals. Calbindin-immunopositive neurons per myenteric ganglion were 36% in SPF, 24% in GF, and 52% in CONV animals. The intact microbiome is essential for normal intrinsic and extrinsic nerve function and gut-brain signaling. © 2015 John Wiley & Sons Ltd.

High-capacity neutron activation analysis facility

International Nuclear Information System (INIS)

Hochel, R.C.

1979-01-01

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

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

International Nuclear Information System (INIS)

Chisela, F.

1986-01-01

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

Development of educational program for neutron activation analysis

International Nuclear Information System (INIS)

Chung, Yong Sam; Moon, Jong Hwa; Kim, Sun Ha; Ryel, Sung; Kang, Young Hwan; Lee, Kil Yong; Yeon, Yeon Yel; Cho, Seung Yeon

2000-08-01

This technical report is developed to apply an educational and training program for graduate student and analyst utilizing neutron activation analysis. The contents of guide book consists of five parts as follows; introduction, gamma-ray spectrometry and measurement statistics, its applications, to understand of comprehensive methodology and to utilize a relevant knowledge and information on neutron activation analysis

Neutron activation analysis applied to energy and environment

International Nuclear Information System (INIS)

Lyon, W.S.

1975-01-01

Neutron activation analysis was applied to a number of problems concerned with energy production and the environment. Burning of fossil fuel, the search for new sources of uranium, possible presence of toxic elements in food and water, and the relationship of trace elements to cardiovascular disease are some of the problems in which neutron activation was used. (auth)

Development of educational program for neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Chung, Yong Sam; Moon, Jong Hwa; Kim, Sun Ha; Ryel, Sung; Kang, Young Hwan; Lee, Kil Yong; Yeon, Yeon Yel; Cho, Seung Yeon

2000-08-01

This technical report is developed to apply an educational and training program for graduate student and analyst utilizing neutron activation analysis. The contents of guide book consists of five parts as follows; introduction, gamma-ray spectrometry and measurement statistics, its applications, to understand of comprehensive methodology and to utilize a relevant knowledge and information on neutron activation analysis.

Neutron capture prompt gamma-ray activation analysis at the NIST cold neutron research facility

Energy Technology Data Exchange (ETDEWEB)

Lindstrom, R M; Zeisler, R; Vincent, D H; Greenberg, R R; Stone, C A; Mackey, E A [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Anderson, D L [Food and Drug Administration, Washington, DC (United States); Clark, D D [Cornell Univ., Ithaca, NY (United States)

1993-01-01

An instrument for neutron capture prompt gamma-ray activation analysis (PGAA) has been constructed as part of the Cold Neutron Research Facility at the 20 MW National Institute of Standards and Technology Research Reactor. The neutron fluence rate (thermal equivalent) is 1.5*10[sup 8] n*cm[sup -2]*s[sup -] [sup 1], with negligible fast neutrons and gamma-rays. With compact geometry and hydrogen-free construction, the sensitivity is sevenfold better than an existing thermal instrument. Hydrogen background is thirtyfold lower. (author) 17 refs.; 2 figs.

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

Science.gov (United States)

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

2017-01-01

Neutron sources are increasingly employed in a wide range of research fields. For some specific purposes an alternative to existing large-scale neutron scattering facilities, can be offered by the new generation of portable neutron devices. This review reports an overview for such recently available neutron generators mainly addressed to biophysics applications with specific reference to portable non-stationary neutron generators applied in Neutron Activation Analysis (NAA). The review reports a description of a typical portable neutron generator set-up addressed to biophysics applications. New generation portable neutron devices, for some specific applications, can constitute an alternative to existing large-scale neutron scattering facilities. Deuterium-Deuterium pulsed neutron sources able to generate 2.5MeV neutrons, with a neutron yield of 1.0×10 6 n/s, a pulse rate of 250Hz to 20kHz and a duty factor varying from 5% to 100%, when combined with solid-state photon detectors, show that this kind of compact devices allow rapid and user-friendly elemental analysis. "This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo". Copyright © 2016 Elsevier B.V. All rights reserved.

A Dosimetry Study of Deuterium-Deuterium Neutron Generator-based In Vivo Neutron Activation Analysis.

Science.gov (United States)

Sowers, Daniel; Liu, Yingzi; Mostafaei, Farshad; Blake, Scott; Nie, Linda H

2015-12-01

A neutron irradiation cavity for in vivo neutron activation analysis (IVNAA) to detect manganese, aluminum, and other potentially toxic elements in human hand bone has been designed and its dosimetric specifications measured. The neutron source is a customized deuterium-deuterium neutron generator that produces neutrons at 2.45 MeV by the fusion reaction 2H(d, n)3He at a calculated flux of 7 × 10(8) ± 30% s(-1). A moderator/reflector/shielding [5 cm high density polyethylene (HDPE), 5.3 cm graphite and 5.7 cm borated (HDPE)] assembly has been designed and built to maximize the thermal neutron flux inside the hand irradiation cavity and to reduce the extremity dose and effective dose to the human subject. Lead sheets are used to attenuate bremsstrahlung x rays and activation gammas. A Monte Carlo simulation (MCNP6) was used to model the system and calculate extremity dose. The extremity dose was measured with neutron and photon sensitive film badges and Fuji electronic pocket dosimeters (EPD). The neutron ambient dose outside the shielding was measured by Fuji NSN3, and the photon dose was measured by a Bicron MicroREM scintillator. Neutron extremity dose was calculated to be 32.3 mSv using MCNP6 simulations given a 10-min IVNAA measurement of manganese. Measurements by EPD and film badge indicate hand dose to be 31.7 ± 0.8 mSv for neutrons and 4.2 ± 0.2 mSv for photons for 10 min; whole body effective dose was calculated conservatively to be 0.052 mSv. Experimental values closely match values obtained from MCNP6 simulations. These are acceptable doses to apply the technology for a manganese toxicity study in a human population.

Advances in 14 MeV neutron activation analysis by means of a new intense neutron source

International Nuclear Information System (INIS)

Pepelnik, R.; Fanger, H.-U.; Michaelis, W.; Anders, B.

1982-01-01

A new intense 14 MeV neutron generator with cylindrical acceleration structure has been put in operation at the GKSS Research Center Geesthacht. The sealed neutron tube is combined with a fast pneumatic rabbit system with particular capabilities for neutron activation analysis involving short-lived reaction products. The sample transfer time is less than 140 ms. The maximum neutron flux available for activation is 5.2x10 10 n/cm 2 s. Theoretical sensitivity predictions made in a previous study have been verified for some important trace elements. As a first application, samples of freeze-dried suspended matter and fishes of the Elbe river were analyzed. (author)

Utilization of the intense pulsed neutron source (IPNS) at Argonne National Laboratory for neutron activation analysis

International Nuclear Information System (INIS)

Heinrich, R.R.; Greenwood, L.R.; Popek, R.J.; Schulke, A.W. Jr.

1983-01-01

The Intense Pulsed Neutron Source (IPNS) neutron scattering facility (NSF) has been investigated for its applicability to neutron activation analysis. A polyethylene insert has been added to the vertical hole VT3 which enhances the thermal neutron flux by a factor of two. The neutron spectral distribution at this position has been measured by the multiple-foil technique which utilized 28 activation reactions and the STAYSL computer code. The validity of this spectral measurement was tested by two irradiations of National Bureau of Standards SRM-1571 (orchard leaves), SRM-1575 (pine needles), and SRM-1645 (river sediment). The average thermal neutron flux for these irradiations normalized to 10 μamp proton beam is 4.0 x 10 11 n/cm 2 -s. Concentrations of nine trace elements in each of these SRMs have been determined by gamma-ray spectrometry. Agreement of measured values to certified values is demonstrated to be within experiment error

Neutron activation analysis in minerals prospecting

International Nuclear Information System (INIS)

Gomez, H.; Duque O, J.

1988-01-01

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

The orientation effect in the activities of neutronic probes

International Nuclear Information System (INIS)

Vigon, M. A.

1956-01-01

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

Activation analysis by filtered neutrons. Preliminary investigation

International Nuclear Information System (INIS)

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

1986-01-01

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

Radiochemical and instrumental neutron activation analysis - recent trends

International Nuclear Information System (INIS)

Dams, R.

1990-01-01

Recent trends of radiochemical and instrumental neutron activation analysis are discussed. Novel developments include the application of cyclic and pulsed activation, better energy resolution with hyperpure germanium detectors, and use of pulse processing systems allowing extremely high count rates of very short-lived isotopes. Further development is anticipated in the field of speciation in biological and environmental studies. Radiochemical methods have led to accurate determinations at the ng/g level. A promising future is expected for neutron activation techniques. (orig.)

Safeguards and Physics Measurements: Neutron Activation Analysis with k0-standardisation

International Nuclear Information System (INIS)

Pomme, S.

2000-01-01

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

High-capacity neutron activation analysis facility

International Nuclear Information System (INIS)

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

1980-01-01

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

Recent applications of neutron activation analysis at Lucas Heights

International Nuclear Information System (INIS)

Fardy, J.J.

1978-01-01

The use of neutron activation analysis to determine key elemental distribution patterns in samples from both the energy industry and health science field is summarised. Instrumental neutron activation analysis has successfully measured simultaneously more than twenty elements in a sample of brown coal from Victoria, black coal from New South Wales and samples from the product stream of ACIRL's batch autoclave, solvent-refined, coal hydrogenation process. Four gallstones removed from the same gallbladder have been examined instrumentally by neutron activation analysis. A total of sixteen trace elements were detected with concentrations in the range 0.8 ng g -1 for gold to 7,800 μg g -1 for calcium

Standardization activities of the Euratom Neutron Radiography Working Group

International Nuclear Information System (INIS)

Domanus, J.

1982-06-01

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

Neutron activation diagnostics at the National Ignition Facility (invited)

Energy Technology Data Exchange (ETDEWEB)

Bleuel, D. L.; Yeamans, C. B.; Bernstein, L. A.; Bionta, R. M.; Caggiano, J. A.; Drury, O. B.; Hagmann, C. A.; Hatarik, R.; Knittel, K. M.; McNaney, J. M.; Moran, M.; Schneider, D. H. G. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Casey, D. T.; Frenje, J. A.; Johnson, M. Gatu [Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Cooper, G. W. [University of New Mexico, Albuquerque, New Mexico 87131 (United States); Knauer, J. P. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Leeper, R. J.; Ruiz, C. L. [Sandia National Laboratory, Albuquerque, New Mexico 87185 (United States)

2012-10-15

Neutron yields are measured at the National Ignition Facility (NIF) by an extensive suite of neutron activation diagnostics. Neutrons interact with materials whose reaction cross sections threshold just below the fusion neutron production energy, providing an accurate measure of primary unscattered neutrons without contribution from lower-energy scattered neutrons. Indium samples are mounted on diagnostic instrument manipulators in the NIF target chamber, 25-50 cm from the source, to measure 2.45 MeV deuterium-deuterium fusion neutrons through the {sup 115}In(n,n'){sup 115m} In reaction. Outside the chamber, zirconium and copper are used to measure 14 MeV deuterium-tritium fusion neutrons via {sup 90}Zr(n,2n), {sup 63}Cu(n,2n), and {sup 65}Cu(n,2n) reactions. An array of 16 zirconium samples are located on port covers around the chamber to measure relative yield anisotropies, providing a global map of fuel areal density variation. Neutron yields are routinely measured with activation to an accuracy of 7% and are in excellent agreement both with each other and with neutron time-of-flight and magnetic recoil spectrometer measurements. Relative areal density anisotropies can be measured to a precision of less than 3%. These measurements reveal apparent bulk fuel velocities as high as 200 km/s in addition to large areal density variations between the pole and equator of the compressed fuel.

Neutron activation of building materials used in the reactor shield

International Nuclear Information System (INIS)

Hernandez, A.T.; Perez, G.; D'Alessandro, K.

1993-01-01

Cuban concretes and their main components (mineral aggregates and cement) were investigated through long-lived activation products induced by neutrons from a reactor. The multielemental content in the materials studied was obtained by neutron activation analysis in an IBR-2 reactor and gamma activation analysis in an MT-25 microtron from Join Institute of Nuclear Research of Dubna. After irradiation of building materials for 30 years by a neutron flow of unitary density, induced radioactivity was calculated according to experimental data. The comparative evaluation of different concretes aggregates and two types of cement related to the activation properties is discussed

Multicomponent activation detector measurements of reactor neutron spectra

International Nuclear Information System (INIS)

Sandberg, J.; Aarnio, P. A.; Routti, J. T.

1984-01-01

Information on the neutron flux is required in many applications of research reactors, such as activation analysis or radiation damage measurements. Flux spectrum measurements are commonly carried out with activation foils. The reaction types used are threshold reactions in the fast energy region, resonance reactions in the intermediate region and neutron capture reactions with l/v-cross section in the thermal region. It has been shown that it is possible to combine several detector elements into homogeneous multicomponent detectors. The activities of all detector reaction products can be determined with a single gamma spectrum measurement. The multicomponent principle sets some restrictions on the choice of detector reactions, for example, each product nuclide may be produced in one reaction only. Separate multicomponent threshold and resonance detectors were designed for the fast and intermediate regions, respectively. The detectors were fabricated in polyethylene irradiation capsules or quartz glass ampoules, and they were irradiated in a cadmium cover. The detectors were succesfully used in the irradiation ring and in the core of a Triga reactor. The intermediate and fast neutron spectrum was unfolded with the least-squares unfolding program LOUHI. According to the preliminary results multicomponent activation detectors might constitute a convenient means for carrying out routine neutron spectrum measurements in research reactors. (orig.)

Determination of europium content in Li_2SiO_3(Eu) by neutron activation analysis using Am-Be neutron source

International Nuclear Information System (INIS)

Naik, Yeshwant; Tapase, Anant Shamrao; Mhatre, Amol; Datrik, Chandrashekhar; Tawade, Nilesh; Kumar, Umesh; Naik, Haladhara

2016-01-01

Circulardiscs of Li_2SiO_3 doped with europium were prepared and a new activation procedure for the neutron dose estimation in a breeder blanket of fusion reactor is described. The amount of europium in the disc was determined by neutron activation analysis (NAA) using an isotopic neutron source. The average neutron absorption cross section for the reaction was calculated using neutron distribution of the Am-Be source and available neutron absorption cross section data for the "1"5"1Eu(n,γ)"1"5"2"mEu reaction, which was used for estimation of europium in the pallet. The cross section of the elements varies with neutron energy, and the flux of the neutrons in each energy range seen by the nuclei under investigation also varies. Neutron distribution spectrum of the Am-Be source was worked out prior to NAA and the effective fractional flux for the nuclear reaction considered for the flux estimation was also determined. - Highlights: • Lithium meta-silicate is breeder materials for a fusion reactor. • Europium is used for neutron dose estimation in a breeder blanket. • It is important to determine amount of europium in lithium meta-silicate. • Amount of europium in lithium meta-silicate was determined by neutron activation and off-line gamma spectrometry.

Fast-neutron activation analysis of manganese nodules

International Nuclear Information System (INIS)

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

1976-01-01

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

Neutron detection using Dy2O3 activation detectors

International Nuclear Information System (INIS)

Gomaa, M.A.; Mohamed, E.J.

1979-01-01

The aim of the present study is to examine the usefulness of Dy 2 O 3 not only as thermal neutron activation detector but also as a fast neutron detector. For thermal neutrons, the half life of 165 Dy is measured to be (141 +- 6) min, its response to thermal neutrons is (2.18 +- 0.01) cpm/ncm -2 s -1 for a 250 mg Dy 2 O 3 pellet. For fast neutrons the Dy 2 O 3 detector is placed within a 20 cm polyethylene sphere and its response is found to be (2.2 +- 0.1) cpm/ncm -2 s -1 for 4 MeV neutrons and (2.10 +- 0.04) cpm/ncm -2 s -1 for 14 MeV neutrons. For neutron dosimetry, its response is found to be (16.7 +- 0.4) cpm per mrem h -1 . (author)

Elemental analysis of fertilizer by fast neutron activation

International Nuclear Information System (INIS)

Bodart, F.; Deconninck, G.

1977-01-01

A simple and accurate technique has been developed to analyse commercial fertilizers for phosphorus, potassium, chlorine, magnesium and silicon. The method is based on fast-neutron activation using a neutron flux of 2x10 11 neutrons/second. The optimum analytical conditions are tabulated. After irradiation, the sample is measured on a conventional counting system including a Ge(Li) detector (10% efficiency and 2 keV resolution for 60 Co) and a multichannel analyser. Monitor foils radioactivity are measured separately at the same time with a 2''x2''NaI detector coupled with a single channel analyser and a scaler. Fast neutron activation has proved to be a fast, simple, reliable and low cost analytical technique for the determination of phosphorus, silicon, potassium, magnesium and chlorine in fertilizers. Not less than five phosphorus determinations are possible in one hour, while two potassium, magnesium and chlorine determinations are made at the same time. (T.G.)

Neutronic investigation and activation calculation for CFETR HCCB blankets

Science.gov (United States)

Shuling, XU; Mingzhun, LEI; Sumei, LIU; Kun, LU; Kun, XU; Kun, PEI

2017-12-01

The neutronic calculations and activation behavior of the proposed helium cooled ceramic breeder (HCCB) blanket were predicted for the Chinese Fusion Engineering Testing Reactor (CFETR) design model using the MCNP multi-particle transport code and its associated data library. The tritium self-sufficiency behavior of the HCCB blanket was assessed, addressing several important breeding-related arrangements inside the blankets. Two candidate first wall armor materials were considered to obtain a proper tritium breeding ratio (TBR). Presentations of other neutronic characteristics, including neutron flux, neutron-induced damages in terms of the accumulated dpa and helium production were also conducted. Activation, decay heat levels and contact dose rates of the components were calculated to estimate the neutron-induced radioactivity and personnel safety. The results indicate that neutron radiation is efficiently attenuated and slowed down by components placed between the plasma and toroidal field coil. The dominant nuclides and corresponding isotopes in the structural steel were discussed. A radioactivity comparison between pure beryllium and beryllium with specific impurities was also performed. After a millennium cooling time, the decay heat of all the concerned components and materials is less than 1 × 10-4 kW, and most associated in-vessel components qualify for recycling by remote handling. The results demonstrate that acceptable hands-on recycling and operation still require a further long waiting period to allow the activated products to decay.

Improved Fission Neutron Data Base for Active Interrogation of Actinides

Energy Technology Data Exchange (ETDEWEB)

Pozzi, Sara; Czirr, J. Bart; Haight, Robert; Kovash, Michael; Tsvetkov, Pavel

2013-11-06

This project will develop an innovative neutron detection system for active interrogation measurements. Many active interrogation methods to detect fissionable material are based on the detection of neutrons from fission induced by fast neutrons or high-energy gamma rays. The energy spectrum of the fission neutrons provides data to identify the fissionable isotopes and materials such as shielding between the fissionable material and the detector. The proposed path for the project is as follows. First, the team will develop new neutron detection systems and algorithms by Monte Carlo simulations and bench-top experiments. Next, They will characterize and calibrate detection systems both with monoenergetic and white neutron sources. Finally, high-fidelity measurements of neutron emission from fissions induced by fast neutrons will be performed. Several existing fission chambers containing U-235, Pu-239, U-238, or Th-232 will be used to measure the neutron-induced fission neutron emission spectra. The challenge for making confident measurements is the detection of neutrons in the energy ranges of 0.01 – 1 MeV and above 8 MeV, regions where the basic data on the neutron energy spectrum emitted from fission is least well known. In addition, improvements in the specificity of neutron detectors are required throughout the complete energy range: they must be able to clearly distinguish neutrons from other radiations, in particular gamma rays and cosmic rays. The team believes that all of these challenges can be addressed successfully with emerging technologies under development by this collaboration. In particular, the collaboration will address the area of fission neutron emission spectra for isotopes of interest in the advanced fuel cycle initiative (AFCI).

Accounting for the thermal neutron flux depression in voluminous samples for instrumental neutron activation analysis

International Nuclear Information System (INIS)

Overwater, R.M.W.; Hoogenboom, J.E.

1994-01-01

At the Delft University of Technology Interfaculty Reactor Institute, a facility has been installed to irradiate cylindrical samples with diameters up to 15 cm and weights up to 50 kg for instrumental neutron activation analysis (INAA) purposes. To be able to do quantitative INAA on voluminous samples, it is necessary to correct for gamma-ray absorption, gamma-ray scattering, neutron absorption, and neutron scattering in the sample. The neutron absorption and the neutron scattering are discussed. An analytical solution is obtained for the diffusion equation in the geometry of the irradiation facility. For samples with known composition, the neutron flux--as a function of position in the sample--can be calculated directly. Those of unknown composition require additional flux measurements on which least-squares fitting must be done to obtain both the thermal neutron diffusion coefficient D s and the diffusion length L s of the sample. Experiments are performed to test the theory

Transportable, Low-Dose Active Fast-Neutron Imaging

Energy Technology Data Exchange (ETDEWEB)

Mihalczo, John T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wright, Michael C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McConchie, Seth M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Archer, Daniel E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Palles, Blake A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-08-01

This document contains a description of the method of transportable, low-dose active fast-neutron imaging as developed by ORNL. The discussion begins with the technique and instrumentation and continues with the image reconstruction and analysis. The analysis discussion includes an example of how a gap smaller than the neutron production spot size and detector size can be detected and characterized depending upon the measurement time.

The main results of the USSR neutron data activities in 1986-1987

International Nuclear Information System (INIS)

Manokhin, V.N.

1988-01-01

The report gives a review of the main results of neutron data activities in USSR and the activity of Nuclear Data Center in 1986-1987, namely concerning the experimental neutron data, the evaluated neutron data and the theoretical work

Preliminary engineering assessment of the HCLL and HCPB Neutron Activation System

Energy Technology Data Exchange (ETDEWEB)

Calderoni, Pattrick; Leichtle, Dieter [Fusion for Energy, Barcelona, (Spain); Angelone, Maurizio [ENEA, Unita Tecnica Fusione, Frascati, (Italy); Klix, Axel [KIT, Eggenstein-Leopoldshafen, (Germany)

2015-07-01

The Neutron Activation System (NAS) is one of the four types of neutronics sensors considered for the testing of the HCLL and HCPB Test Blanket Module (TBM) in ITER. It measures the absolute neutron flux intensity with information on the neutron spectrum in selected positions of the TBM. The working principle of the NAS is as follows: the system moves small activation probes (capsules) into selected positions in the TBM (irradiation ends) by means of pneumatic transport with pressurized helium gas; the capsules are irradiated for a selected period, depending on their materials composition (several tens of seconds up to the full plasma pulse length); immediately after the irradiation they are extracted and transported to a gamma spectrometer by means of the same pneumatic transport system; the gamma spectrometer determines the induced gamma activity; the neutron flux and neutron fluence is calculated from the measured gamma activity and the known activation cross section of the materials in the activation probe; after the measurement the capsule is sent either to a disposal or storage (for later measurement). This paper summarizes the results of the feasibility assessment of the TBM NAS in the conceptual design phase, including design justification, identification of requirements based on the expected operating conditions in ITER and preliminary engineering assessment of the activation materials, irradiation ends integration in the modules design and the counting station. (authors)

Activation analysis with reactor neutrons

International Nuclear Information System (INIS)

Gangadharan, S.

1983-01-01

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

Neutron activation analysis-comparative (NAAC)

International Nuclear Information System (INIS)

Zimmer, W.H.

1979-01-01

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

Elemental analysis of brazing alloy samples by neutron activation technique

International Nuclear Information System (INIS)

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

1996-01-01

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

Elemental analysis of brazing alloy samples by neutron activation technique

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-31

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

Analysis of some Egyptian cosmetic samples by fast neutron activation analysis

International Nuclear Information System (INIS)

Medhat, M.E.; Ali, M.A.; Hassan, M.F.

2001-01-01

A description of D-T neutron generator (NG) is presented. This generator can be used for fast neutron activation analysis applied to determine some selected elements, especially light elements, in different materials. The concentrations of the elements Na, Mg, Al, Si, K, Cl, Ca and Fe were determined in two domestic brands of face powder by using 14 MeV neutron activation analysis

Active-interrogation measurements of fast neutrons from induced fission in low-enriched uranium

International Nuclear Information System (INIS)

Dolan, J.L.; Marcath, M.J.; Flaska, M.; Pozzi, S.A.; Chichester, D.L.; Tomanin, A.; Peerani, P.

2014-01-01

A detection system was designed with MCNPX-PoliMi to measure induced-fission neutrons from U-235 and U-238 using active interrogation. Measurements were then performed with this system at the Joint Research Centre in Ispra, Italy on low-enriched uranium samples. Liquid scintillators measured induced fission neutrons to characterize the samples in terms of their uranium mass and enrichment. Results are presented to investigate and support the use of organic liquid scintillators with active interrogation techniques to characterize uranium containing materials. -- Highlights: • We studied low-enriched uranium using active-interrogation experiments including a deuterium–tritium neutron generator and an americium–lithium isotopic neutron source. • Liquid scintillators measured induced-fission neutrons from the active-interrogation methods. • Fast-neutron (DT) and thermal-neutron (Am–Li) interrogation resulted in the measurement of trends in uranium mass and 235 U enrichment respectively. • MCNPX-PoliMi, the Monte Carlo transport code, simulated the measured induced-fission neutron trends in the liquid scintillators

Active-interrogation measurements of fast neutrons from induced fission in low-enriched uranium

Energy Technology Data Exchange (ETDEWEB)

Dolan, J.L., E-mail: jldolan@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Marcath, M.J.; Flaska, M.; Pozzi, S.A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Chichester, D.L. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Tomanin, A.; Peerani, P. [European Commission, Joint Research Centre, Institute for Transuranium Elements, Ispra (Italy)

2014-02-21

A detection system was designed with MCNPX-PoliMi to measure induced-fission neutrons from U-235 and U-238 using active interrogation. Measurements were then performed with this system at the Joint Research Centre in Ispra, Italy on low-enriched uranium samples. Liquid scintillators measured induced fission neutrons to characterize the samples in terms of their uranium mass and enrichment. Results are presented to investigate and support the use of organic liquid scintillators with active interrogation techniques to characterize uranium containing materials. -- Highlights: • We studied low-enriched uranium using active-interrogation experiments including a deuterium–tritium neutron generator and an americium–lithium isotopic neutron source. • Liquid scintillators measured induced-fission neutrons from the active-interrogation methods. • Fast-neutron (DT) and thermal-neutron (Am–Li) interrogation resulted in the measurement of trends in uranium mass and {sup 235}U enrichment respectively. • MCNPX-PoliMi, the Monte Carlo transport code, simulated the measured induced-fission neutron trends in the liquid scintillators.

Vanadium determination in pretoleum by neutron activation analysis

International Nuclear Information System (INIS)

Lopez, M.; Espinosa, R.

1983-01-01

The vanadium concentration in an Peruvian petroleum sample is determined by neutron activation analysis. The samples were irradiated for 20 minutes with a flux of thermal neutrons of 1.75 x 10 7 n/cm 2 -s in a subcritical assembly. The activity of the created samples decreases to half 15 minutes after the irradiation. The result is 28.3 +- 0.8 p.p.m. with a typical deviation of 2.8%. The detection limit of this method is 4 p.p.m

Optimization to the medical facilities for Neutron activation analysis

International Nuclear Information System (INIS)

Franklin Mergarerejo, Ricardo; GarcIa Parra, Lazaro; Desdin, Luis Felipe; Lopez Aldama, Daniel

2001-01-01

A method of detection of the Fluorine is presented by means of the neutron activation analysis. This method supposes an accuracy in the determination of any very high element (of the ppm order); but having the particularity that with Oxygen and Fluorine after certain nuclear reactions are obtained the same reaction product (son). This implies serious inconveniences since an interference he/she takes place among the activation of the Oxygen and of the Fluorine falsifying the reading. To save this inconvenience and to take advantage of the kindness of this method it is known that the Oxygen is activated for neutrons with superior energy to the 10.5 MeV, while the Fluorine for energy of the superior incident neutrons to the 1.5 MeV. We think about as hypothesis that is possible to reduce the interference of the Oxygen using a moderator in order to affect the statistic of the count the less possible thing. The objective of the present work is to design and to optimize an installation to measure concentrations of Fluorine in presence of Oxygen using neutrons of 14 MeV coming from a generator of neutrons of the type NG-12-1. To fulfill our objective leaving of the hypothesis an experimental simulation it was implemented using mathematical methods of having proven efficiency in the transport of neutrons like the method of Mount Carlo (specifically the code MCNP-)

Activity report on neutron scattering research. V. 1, 1994

International Nuclear Information System (INIS)

Fujii, Y.; Oohara, Y.

1994-09-01

In April, 1993, the Neutron Scattering Laboratory attached to the Institute for Solid State Physics, University of Tokyo, was newly established in Tokai, Ibaraki Prefecture, to promote nationwide users' programs for utilizing the university-owned neutron instruments installed at the JRR-3M reactor of Japan Atomic Energy Research Institute. This upgraded reactor (20 MW, the cold source is installed) has drastically expanded the number of users and research areas since 1990 when it became operational. Currently 8 and 3 out of 18 new spectrometers in total at the JRR-3M are owned by ISSP and Tohoku University, respectively, while the remaining 7 spectrometers belong to JAERI. In addition, 3 conventional spectrometers in the 30 years old JRR-2 reactor (10 MW) have also supported research activities. This is the first issue of 'Activity report on neutron scattering research', and it is to be published annually. In this report, the brief history of neutron scattering research, the users' programs, the committees, the neutron scattering instruments available at the JRR-3M and the JRR-2M, the activity reports on structures and excitation, magnetism, superconductors, liquid and glass, material science, polymers, biology and instrumentation, and publication list are reported. (K.I.)

Activation measurements for fast neutrons. Part E. Evaluation of fast neutron 63Ni transmission factors

International Nuclear Information System (INIS)

Egbert, Stephen D.

2005-01-01

The 63 Ni measurements for fast neutrons in copper samples are compared to the calculated free-in-air 63 Ni neutron activation given in Chapter 3 by use of transmission factors. Transmission factors were calculated to account for the modification of the fluence and activation at each sample's in situ location. For the purposes of this discussion, the transmission factor (TF) is defined as the ratio of the in situ sample activation divided by the untilted free-in-air (FIA) activation at a height of 1 m above ground at the same ground range. Examples of the application of TF's will be provided in this section. (author)

Neutron activation analysis in archaeological chemistry

Energy Technology Data Exchange (ETDEWEB)

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

1990-01-01

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

Neutron activation analysis in archaeological chemistry

International Nuclear Information System (INIS)

Harbottle, G.

1990-01-01

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

Some Applications of Fast Neutron Activation Analysis of Oxygen

Energy Technology Data Exchange (ETDEWEB)

Owrang, Farshid

2003-07-01

In this thesis we focus on applications of neutron activation of oxygen for several purposes: A) measuring the water level in a laboratory tank, B) measuring the water flow in a pipe system set-up, C) analysing the oxygen in combustion products formed in a modern gasoline SI engine, and D) measuring on-line the amount of oxygen in bulk liquids. A) Water level measurements. The purpose of this work was to perform radiation based water level measurements, aimed at nuclear reactor vessels, on a laboratory scale. A laboratory water tank was irradiated by fast neutrons from a neutron generator. The water was activated at different water levels and the water level was decreased. The produced gamma radiation was measured using two detectors at different heights. The results showed that the method is suitable for measurement of water level and that a relatively small experimental set-up can be used for developing methods for water level measurements in real boiling water reactors based on activated oxygen in the water. B) Water flows in pipe. The goal in this work was to investigate the asymmetric distribution of activity in flow measurements with pulsed neutron activation (PNA) in a laboratory piping system. Earlier investigations had shown a discrepancy between the measured velocity of the activated water by PNA and the true mean velocity in the pipe. This discrepancy decreased with larger distances from the activation point. It was speculated that the induced activity in the pipe did not distribute homogeneously. With inhomogeneous radial distribution of activity in combination with a velocity profile in the pipe, the activated water may not have the same velocity as the mean velocity of water in the pipe. To study this phenomenon, a water-soluble colour was injected into a transparent pipe for simulation of the transport of the activated water. The radial concentration of the colour, at different distances from the activation point, was determined. The result

Some Applications of Fast Neutron Activation Analysis of Oxygen

International Nuclear Information System (INIS)

Owrang, Farshid

2003-01-01

In this thesis we focus on applications of neutron activation of oxygen for several purposes: A) measuring the water level in a laboratory tank, B) measuring the water flow in a pipe system set-up, C) analysing the oxygen in combustion products formed in a modern gasoline SI engine, and D) measuring on-line the amount of oxygen in bulk liquids. A) Water level measurements. The purpose of this work was to perform radiation based water level measurements, aimed at nuclear reactor vessels, on a laboratory scale. A laboratory water tank was irradiated by fast neutrons from a neutron generator. The water was activated at different water levels and the water level was decreased. The produced gamma radiation was measured using two detectors at different heights. The results showed that the method is suitable for measurement of water level and that a relatively small experimental set-up can be used for developing methods for water level measurements in real boiling water reactors based on activated oxygen in the water. B) Water flows in pipe. The goal in this work was to investigate the asymmetric distribution of activity in flow measurements with pulsed neutron activation (PNA) in a laboratory piping system. Earlier investigations had shown a discrepancy between the measured velocity of the activated water by PNA and the true mean velocity in the pipe. This discrepancy decreased with larger distances from the activation point. It was speculated that the induced activity in the pipe did not distribute homogeneously. With inhomogeneous radial distribution of activity in combination with a velocity profile in the pipe, the activated water may not have the same velocity as the mean velocity of water in the pipe. To study this phenomenon, a water-soluble colour was injected into a transparent pipe for simulation of the transport of the activated water. The radial concentration of the colour, at different distances from the activation point, was determined. The result

Radioactive waste characterisation by neutron activation

International Nuclear Information System (INIS)

Nicol, Tangi

2016-01-01

Nuclear activities produce radioactive wastes classified following their radioactive level and decay time. an accurate characterization is necessary for efficient classification and management. Medium and high level wastes containing long lived radioactive isotopes will be stored in deep geological storage for hundreds of thousands years. at the end of this period, it is essential to ensure that the wastes do not represent any risk for humans and environment, not only from radioactive point of view, but also from stable toxic chemicals. This PhD thesis concerns the characterization of toxic chemicals and nuclear material in radioactive waste, by using neutron activation analysis, in the frame of collaboration between the Nuclear Measurement Laboratory of CEA Cadarache, France, and the Institute of Nuclear Waste Management and Reactor Safety of the research center, FZJ (Forschungszentrum Juelich GmbH), Germany. The first study is about the validation of the numerical model of the neutron activation cell MEDINA (FZJ), using MCNP Monte Carlo transport code. Simulations and measurements of prompt capture gamma rays from small samples measured in MEDINA have been compared for a number of elements of interest (beryllium, aluminum, chlorine, copper, selenium, strontium, and tantalum). The comparison was performed using different nuclear databases, resulting in satisfactory agreement and validating simulation in view of following studies. Then, the feasibility of fission delayed gamma-ray measurements of "2"3"9Pu and "2"3"5U in 225 L waste drums has been studied, considering bituminized or concrete matrixes representative of wastes produced in France and Germany. The delayed gamma emission yields were first determined from uranium and plutonium metallic samples measurements in REGAIN, the neutron activation cell of LMN, showing satisfactory consistency with published data. The useful delayed gamma signals of "2"3"9Pu and "2"3"5U, homogeneously distributed in the 225 L

Analysis of Some Egyptian Cosmetic Samples by Fast Neutron Activation Analysis

CERN Document Server

Medhat, M E; Fayez-Hassan, M

2001-01-01

A description of D-T neutron generator (NG) is presented. This generator can be used for fast neutron activation analysis applied to determine some selected elements, especially light elements, in different materials. In our work, the concentration of the elements Na, Mg, Al, Si, K, Cl, Ca and Fe, were determined in two domestic brands of face powder by using 14 MeV neutron activation analysis.

Neutron activation analysis for certification of standard reference materials

International Nuclear Information System (INIS)

Capote Rodriguez, G.; Perez Zayas, G.; Hernandez Rivero, A.; Ribeiro Guevara, S.

1996-01-01

Neutron activation analysis is used extensively as one of the analytical techniques in the certification of standard reference materials. Characteristics of neutron activation analysis which make it valuable in this role are: accuracy multielemental capability to asses homogeneity, high sensitivity for many elements, and essentially non-destructive method. This paper report the concentrations of 30 elements (major, minor and trace elements) in four Cuban samples. The samples were irradiated in a thermal neutron flux of 10 12- 10 13 n.cm 2. s -1. The gamma ray spectra were measured by HPGe detectors and were analyzed using ACTAN program development in Center of Applied Studies for Nuclear Development

Radioactive waste package assay facility. Volume 2. Investigation of active neutron and active gamma interrogation

International Nuclear Information System (INIS)

Bailey, M.; Bunce, L.J.; Findlay, D.J.S.; Jolly, J.E.; Parsons, T.V.; Sene, M.R.; Swinhoe, M.T.

1992-01-01

Volume 2 of this report describes the theoretical and experimental work carried out at Harwell on active neutron and active gamma interrogation of 500 litre cemented intermediate level waste drums. The design of a suitable neutron generating target in conjunction with a LINAC was established. Following theoretical predictions of likely neutron responses, an experimental assay assembly was built. Responses were measured for simulated drums of ILW, based on CAGR, Magnox and PCM wastes. Good correlations were established between quantities of 235 -U, nat -U and D 2 O contained in the drums, and the neutron signals. Expected sensitivities are -1g of fissile actinide and -100g of total actinide. A measure of spatial distribution is obtainable. The neutron time spectra obtained during neutron interrogation were more complex than expected, and more analysis is needed. Another area of discrepancy is the difference between predicted and measured thermal neutron flux in the drum. Clusters of small 3 He proportional counters were found to be much superior for fast neutron detection than larger diameter counters. It is necessary to ensure constancy of electron beam position relative to target(s) and drum, and prudent to measure the target neutron or gamma output as appropriate. 59 refs., 77 figs., 11 tabs

The synchronous active neutron detection system for spent fuel assay

International Nuclear Information System (INIS)

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

1994-01-01

The authors have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit the unique operating features of a 14-MeV neutron generator developed by Schlumberger. This generator and a novel detection system will be applied to the direct measurement of the fissile material content in spent fuel in place of the indirect measures used at present. The technique they are investigating is termed synchronous active neutron detection (SAND). It closely follows a method that has been used routinely in other branches of physics to detect very small signals in the presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed open-quotes lock-inclose quotes amplifiers. The authors have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. This approach is possible because the Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. The results to date are preliminary but quite promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly. It also appears to be quite resilient to background neutron interference. The interrogating neutrons appear to be nonthermal and penetrating. Although a significant amount of work remains to fully explore the relevant physics and optimize the instrument design, the underlying concept appears sound

Prompt-gamma neutron activation analysis system design: Effects of D-T versus D-D neutron generator source selection

Science.gov (United States)

Prompt-gamma neutron activation (PGNA) analysis is used for the non-invasive measurement of human body composition. Advancements in portable, compact neutron generator design have made those devices attractive as neutron sources. Two distinct generators are available: D-D with 2.5 MeV and D-T with...

Activation method for measurement of neutron spectrum parameters

International Nuclear Information System (INIS)

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

2007-01-01

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

System to detect nuclear materials by active neutron method

International Nuclear Information System (INIS)

Koroev, M.; Korolev, Yu.; Lopatin, Yu.; Filonov, V.

1999-01-01

The report presents the results of the development of the system to detect nuclear materials by active neutron method measuring delayed neutrons. As the neutron source the neutron generator was used. The neutron generator was controlled by the system. The detectors were developed on the base of the helium-3 counters. Each detector consist of 6 counters. Using a number of such detectors it is possible to verify materials stored in different geometry. There is an spectrometric scintillator detector in the system which gives an additional functional ability to the system. The system could be used to estimate the nuclear materials in waste, to detect the unauthorized transfer of the nuclear materials, to estimate the material in tubes [ru

Diagnosis of mucoviscidosis by neutron activation analysis. Part 1

International Nuclear Information System (INIS)

Bellido, Luis F.; Bellido, Alfredo V.

1997-02-01

Symptoms pathology, incidence, and gravity of the inherent syndrome called mucoviscidosis, or cystic fibrosis are described in this Part I. The analytical methods used for its diagnosis, both the conventional chemical ones and by neutron activation analysis are also summarised. Finally, an analytical method to study the incidence of mucoviscidosis in Brazil is presented. This , essentially, consists in bromine determination, in fingernails, by resonance neutron activation analysis. (author)

Long distance elementary measurement of the radiation dose ratio produced by neutron activation

International Nuclear Information System (INIS)

Zhou Changgeng; Lou Benchao; Wu Chunlei; Hu Yonghong; Li Yan

2009-04-01

The working principle and the structure and performances of a long distance controllable individual radiation dose ratio instrument are described. The radiation dose ratio produced by neutron activation is elementarily measured by using this instrument in the neutron generator hall with high neutron yield. When neutron yield arrives to 2 x 10 11 s -1 , the radiation dose ratio produced by neutron activation is 99.9 μSv/h in 1 h after the generator being stopped. The radiation dose ratio is reduced to 24.4 μSv/h in 39 h after the generator being stopped. When neutron yield is 3.2 x 10 10 s -1 , the radiation dose ratio produced by neutron activation is 21.9 μSv/h in 36 min, after the generator being stopped. The measurement results may provide reference for physical experimenters and neutron generator operators. (authors)

Activation measurements of fast neutron radiative capture for 139La

International Nuclear Information System (INIS)

Luo, Junhua; Han, Jiuning; Liu, Rong; Jiang, Li; Liu, Zhenlai; Sun, Guihua; Ge, Suhong

2013-01-01

The neutron capture cross section of the neutron magic isotope 139 La has been measured relative to that of 27 Al by means of the activation method. The fast neutrons were produced via the 3 H(d,n) 4 He reaction on Pd-300 neutron generator. The natural high-purity La 2 O 3 powder was used as target material. Induced gamma activities were measured by a high-resolution gamma-ray spectrometer with high-purity germanium (HPGe) detector. Measurements were corrected for gamma-ray attenuations, random coincidence (pile-up), dead time and fluctuation of neutron flux. The new values for E n =13.5±0.2, 14.1±0.2, and 14.8±0.2 MeV are found to be 1.30±0.08, 1.15±0.08 and 0.99±0.07 mb, respectively. Results were discussed and compared with some corresponding values found in the literature. - Highlights: ► D–T neutron source was used to measure cross sections using activation method. ► 27 Al(n,α) 24 Na was used as the monitor for the measurement. ► The cross sections for the (n,γ) reactions on neutron magic isotope 139 La have been measured. ► The data for 139 La(n,γ) 140 La reaction are presented. ► The results were compared with previous data and with evaluation data

Passive neutron dosemeter with activation detector

Energy Technology Data Exchange (ETDEWEB)

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

2011-10-15

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

Applications of neutron activation analysis technique

International Nuclear Information System (INIS)

Jonah, S. A.

2000-07-01

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

A new facility for rapid neutron activation analysis

International Nuclear Information System (INIS)

Zeisler, R.; Makarewicz, M.; Grass, F.; Casta, J.

1996-01-01

Many research groups have undertaken efforts on the utilization of short-lived nuclides in a broad spectrum of neutron activation analysis (NAA) applications. The advantages of these approaches are obvious because the information on the sample can be extracted more rapidly. In addition to its other advantages, NAA can become extremely competitive in price and analysis time. Nevertheless, NAA with short-lived nuclides has not gained broad popularity, perhaps because of some difficulties in accuracy and the availability of suitable irradiation facilities. This report discusses the ASTRA reactor for neutron activation analysis capabilities

Neutron activation analysis for antimetabolites. [in food samples

Science.gov (United States)

1973-01-01

Determination of metal ion contaminants in food samples is studied. A weighed quantity of each sample was digested in a concentrated mixture of nitric, hydrochloric and perchloric acids to affect complete solution of the food products. The samples were diluted with water and the pH adjusted according to the specific analysis performed. The samples were analyzed by neutron activation analysis, polarography, and atomic absorption spectrophotometry. The solid food samples were also analyzed by neutron activation analysis for increased sensitivity and lower levels of detectability. The results are presented in tabular form.

Thermal, intermediate and fast neutron flux measurements using activation detectors; Mesure des flux de neutrons thermiques, intermediaires et rapides au moyen de detecteurs par activation

Energy Technology Data Exchange (ETDEWEB)

Brisbois, J; Lott, M; Manent, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

The problem of neutron flux measurements using activation detectors is studied in the particular case of protection research. It is shown how it possible, it is possible, using a known thermal flux, to organise a coherent calibration system for all the detectors. The rapid neutron detectors are calibrated with respect to a reference detector (phosphorus) in a natural uranium converter; the intermediate neutron detectors with respect to gold in the axial channel of ZOE. This method makes it possible to minimise the errors due to the activation cross-sections. A brief description is given of the counting room of the Pile Safety Study Service, as well of the practical utilisation characteristics of the counters employed. (authors) [French] Le probleme de la mesure des flux de neutrons au moyen de detecteurs par activation est etudie dans le cas particulier des etudes de protections. On montre comment, a partir d'un flux thermique connu, on peut organiser un systeme coherent d'etalonnage de tous les detecteurs. Les detecteurs de neutrons rapides sont etalonnes par rapport a un detecteur de reference (phosphore) dans un convertisseur en uranium naturel; les detecteurs de neutrons intermediaires, par rapport a l'or dans le canal axial de ZOE, Cette methode permet de minimiser les erreurs dues aux sections efficaces d'activation. On decrit sommairement la salle de comptage du Service d'Etudes de Protections de Piles et on indique les caracteristiques d'emploi pratique des detecteurs utilises. (auteurs)

On the research activities in reactor and neutron physics using the first egyptian research reactor

International Nuclear Information System (INIS)

Hassan, A.M.

2000-01-01

A review on the most important research activities in reactor and neutron physics using the first Egyptian Research Reactor (ET-RR-1) is given. An out look on: neutron cross-sections, neutron flux, neutron capture gamma-ray spectroscopy, neutron activation analysis, neutron diffraction and radiation shielding experiments, is presented

Neutron activation analysis of monomineral fractions

International Nuclear Information System (INIS)

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

1977-01-01

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

Activation method for measuring the neutron spectra parameters. Computer software

International Nuclear Information System (INIS)

Efimov, B.V.; Ionov, V.S.; Konyaev, S.I.; Marin, S.V.

2005-01-01

The description of mathematical statement of a task for definition the spectral characteristics of neutron fields with use developed in RRC KI unified activation detectors (UKD) is resulted. The method of processing of results offered by authors activation measurements and calculation of the parameters used for an estimation of the neutron spectra characteristics is discussed. Features of processing of the experimental data received at measurements of activation with using UKD are considered. Activation detectors UKD contain a little bit specially the picked up isotopes giving at irradiation peaks scale of activity in the common spectrum scale of activity. Computing processing of results of the measurements is applied on definition of spectrum parameters for nuclear reactor installations with thermal and close to such power spectrum of neutrons. The example of the data processing, the measurements received at carrying out at RRC KI research reactor F-1 is resulted [ru

Determination of iodine 129 in vegetables using neutron activation analysis

International Nuclear Information System (INIS)

Quintana, Eduardo E.; Thyssen, Sandra M.; Bruno, Hector A.

1999-01-01

The developed methodology allows the determination of iodine 129 in vegetables, using neutron activation analysis. The chemical treatment removes the interferences present in these matrixes, as well as the bromine 82 originated in the activation process. The experimental method for the determination of iodine 129 by neutron activation analysis involves five steps: 1- digestion by alkaline fusion; 2- pre-irradiation purification of iodine 129 by distillation followed by solvent extraction, and adsorption on activated charcoal by distillation; 3- neutron irradiation; 4- post-irradiation purification of iodine 130 by distillation followed by solvent extraction; 5- gamma spectrometry. A chemical recovery of 95 % is obtained in the distillations, measured using iodine 131 as tracer. The whole process recovery is within 70 % and 85 %. The detection limit is 2 mBq/kg of sample, but several factors affect this value, such as type of vegetable, natural iodine concentration, irradiation time and neutron flux. The methodology developed is applied at environmental surveillance with safeguards proposes, in the detection of undeclared reprocessing of irradiated fuel. (authors)

Designing on-line analyzer for coal on belt conveyor using neutron activation technique

International Nuclear Information System (INIS)

Rony Djokorayono; Agus Cahyono

2014-01-01

Basic design of on-line analyzer for coal on belt conveyor using neutron activation technique has been carried out. Compared with sampling technique, this neutron activation technique has some advantages in term of analysis accuracy and time. The design activities performed include the establishment of design requirements, functional requirements, technical requirements, technical specification, detection sub-system design, data acquisition subsystem design, and operator computer console design. This program will use Nal(Tl) scintillation detector to detect gamma-rays emitted by elements in coal due to neutron activation of a neutron source, "2"5"2Cf (Californium-252). This basic design of on-line analyzer for coal on belt conveyor using neutron activation technique should be followed up with the development of detailed design, prototype construction, and field testing. (author)

Neutron Activation Analysis with k0 standardisation

International Nuclear Information System (INIS)

Pomme, S.

1998-01-01

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

Thermal neutron imaging in an active interrogation environment

International Nuclear Information System (INIS)

Vanier, P.E.; Forman, L.; Norman, D.R.

2009-01-01

We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of excitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutronemitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

Neutron activation analysis: an emerging technique for conservation/preservation

International Nuclear Information System (INIS)

Sayre, E.V.

1976-01-01

The diverse applications of neutron activation in analysis, preservation, and documentation of art works and artifacts are described with illustrations for each application. The uses of this technique to solve problems of attribution and authentication, to reveal the inner structure and composition of art objects, and, in some instances to recreate details of the objects are described. A brief discussion of the theory and techniques of neutron activation analysis is also included

The comparison of four neutron sources for Prompt Gamma Neutron Activation Analysis (PGNAA) in vivo detections of boron.

Science.gov (United States)

Fantidis, J G; Nicolaou, G E; Potolias, C; Vordos, N; Bandekas, D V

A Prompt Gamma Ray Neutron Activation Analysis (PGNAA) system, incorporating an isotopic neutron source has been simulated using the MCNPX Monte Carlo code. In order to improve the signal to noise ratio different collimators and a filter were placed between the neutron source and the object. The effect of the positioning of the neutron beam and the detector relative to the object has been studied. In this work the optimisation procedure is demonstrated for boron. Monte Carlo calculations were carried out to compare the performance of the proposed PGNAA system using four different neutron sources ( 241 Am/Be, 252 Cf, 241 Am/B, and DT neutron generator). Among the different systems the 252 Cf neutron based PGNAA system has the best performance.

Bayesian statistics applied to neutron activation data for reactor flux spectrum analysis

International Nuclear Information System (INIS)

Chiesa, Davide; Previtali, Ezio; Sisti, Monica

2014-01-01

Highlights: • Bayesian statistics to analyze the neutron flux spectrum from activation data. • Rigorous statistical approach for accurate evaluation of the neutron flux groups. • Cross section and activation data uncertainties included for the problem solution. • Flexible methodology applied to analyze different nuclear reactor flux spectra. • The results are in good agreement with the MCNP simulations of neutron fluxes. - Abstract: In this paper, we present a statistical method, based on Bayesian statistics, to analyze the neutron flux spectrum from the activation data of different isotopes. The experimental data were acquired during a neutron activation experiment performed at the TRIGA Mark II reactor of Pavia University (Italy) in four irradiation positions characterized by different neutron spectra. In order to evaluate the neutron flux spectrum, subdivided in energy groups, a system of linear equations, containing the group effective cross sections and the activation rate data, has to be solved. However, since the system’s coefficients are experimental data affected by uncertainties, a rigorous statistical approach is fundamental for an accurate evaluation of the neutron flux groups. For this purpose, we applied the Bayesian statistical analysis, that allows to include the uncertainties of the coefficients and the a priori information about the neutron flux. A program for the analysis of Bayesian hierarchical models, based on Markov Chain Monte Carlo (MCMC) simulations, was used to define the problem statistical model and solve it. The first analysis involved the determination of the thermal, resonance-intermediate and fast flux components and the dependence of the results on the Prior distribution choice was investigated to confirm the reliability of the Bayesian analysis. After that, the main resonances of the activation cross sections were analyzed to implement multi-group models with finer energy subdivisions that would allow to determine the

DETERMINATION OF LIMIT DETECTION OF THE ELEMENTS N, P, K, Si, Al, Fe, Cu, Cd, WITH FAST NEUTRON ACTIVATION USING NEUTRON GENERATOR

OpenAIRE

Sunardi, Sunardi; Muryono, Muryono

2010-01-01

Determination of limit detection of the elements N, P, K, Si, Al, Fe, Cu, Cd, with fast neutron activation using neutron generator has been done.  Samples prepared from SRM 2704, N, P, K elements from MERCK, Cu, Cd, Al from activation foil made in San Carlos, weighted and packed for certain weight then iradiated during 30 minutes with 14 MeV fast neutron using the neutron generator and then counted with gamma spectrometry (accuspec).  At this research condition of neutron generator was set at...

Active Interrogation of Sensitive Nuclear Material Using Laser Driven Neutron Beams

International Nuclear Information System (INIS)

Favalli, Andrea; Roth, Markus

2015-01-01

An investigation of the viability of a laser-driven neutron source for active interrogation is reported. The need is for a fast, movable, operationally safe neutron source which is energy tunable and has high-intensity, directional neutron production. Reasons for the choice of neutrons and lasers are set forth. Results from the interrogation of an enriched U sample are shown.

Fission and activation of uranium by fashion-plasma neutrons

International Nuclear Information System (INIS)

Lee, J.H.; Hochl, F.; McFarland, D.R.

1978-01-01

Disks of enriched and depleted uranium were irradiated by neutrons from the D-D fusions in a dense plasma-focus. A fission yield of 10 6 fissions-cm -3 in U 235 per pulse was determined with Ge(Li) gamme-ray spectrometry. Activation of U 238 caused increased beta activity after the plasma-neutron irradiation but alpha-particle spectrometry showed Pu 239 production was negligible. In addition, with a disk of lithium in the apparatus, 13.3 MeV neutrons from 7 Li(d,n) 8 Be was observed with a 80-m time-of-flight neutron detector. Dense plasma focuses are now operated not only in a single coaxial gun, but also in improved geometries, such as the hypocycloidal pinch and the staged plasma focus, from which a multiple plasma-focus array suitable for experimental verification of, and eventuel development into a fusion-fission hybrid reactor could be produced. (orig.) [de

Experiment for water-flow measurement by pulsed-neutron activation

International Nuclear Information System (INIS)

Drozdowicz, K.

1994-08-01

An experiment is presented which constitutes a feasibility study for applying the neutron activation method for measurement of the water mass transport in pipings, e.g. in nuclear power stations. The fast neutron generator has been used as a pulsed-neutron activation source for oxygen in water which circulated in a closed system. The γ radiation of the nitrogen product isotope has been measured by the scintillation detectors placed in two positions at the piping. The two time distributions of the pulses have been recorded by a multiscaler (a software design based on CAMAC). The water flow velocity has been estimated from the peak-to-peak time distance. The tests have been performed under different experimental conditions (the neutron pulse duration, the time channel width, the water flow velocity) to define the stability, reproducibility and reliability of the measurement. The detailed results are presented in tables and in time distribution plots. The method has been found useful for the application considered. 4 refs, 17 figs, 5 tabs

The multielement potential of fast neutron cyclic activation analysis

International Nuclear Information System (INIS)

Nonie, S.E.; Randle, K.

1994-01-01

Cyclic neutron activation analysis (CNAA) has, in recent years been developed as a useful analytical tool for the assay of short-lived isotopes in single element situations. The work described in this paper investigates the potential of the technique for composite samples having a wide range of elements that produce short-lived and long-lived isotopes on neutron irradiation. Accelerator-derived neutrons with average energies of 3 MeV, 6 MeV and 14 MeV were employed in what has been dubbed 'Fast Neutron Cyclic Neutron Activation Analysis' (FNCAA). The approach to multi-element analysis entailed: determination of cycle parameters in single element samples via the reactions 27 Al(n,p) 27 Mg(9.6 min,E γ =840keV), and 137 Ba(n,n 'γ137m Ba(2.3 min,E γ 137m Ba(2.3 min,E γ =662 keV), a test of the method on a composite rock sample, determination of analytical sensitivities using both powdered kale and rock standards and a comparison of analytical results with other techniques. The results obtained in all these measurements are presented and discussed. (author) 10 refs.; 3 figs.; 5 tabs

Feasibility study of a neutron activation system for EU test blanket systems

Energy Technology Data Exchange (ETDEWEB)

Tian, Kuo, E-mail: kuo.tian@kit.edu [Institute for Neutron Physics and Reactor Technology, Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Calderoni, Pattrick [Fusion for Energy(F4E), Barcelona (Spain); Ghidersa, Bradut-Eugen; Klix, Axel [Institute for Neutron Physics and Reactor Technology, Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany)

2016-11-01

Highlights: • This paper summarizes the technical baseline and preliminary design of EU TBM Neutron Activation System, briefly describes the key components, and outlines the major integration challenges. - Abstract: The Neutron Activation System (NAS) for the EU Helium Cooled Lithium Lead (HCLL) and Helium Cooled Pebble Bed (HCPB) Test Blanket Systems (TBSs) is an instrument that is proposed to determine the absolute neutron fluence and absolute neutron flux with information on the neutron spectrum in selected positions of the corresponding Test Blanket Modules (TBMs). In the NAS activation probes are exposed to the ITER neutron flux for periods ranging from several tens of seconds up to a full plasma pulse length, and the induced gamma activities are subsequently measured. The NAS is composed of a pneumatic transfer system and a counting station. The pneumatic transfer system includes irradiation ends in TBMs, transfer pipes, return gas pipes, a transfer station with a distributor (carousel), and a pressurized gas driving system, while the counting station consists of gamma ray detectors, signal processing electronic devices, and data analyzing software for neutron source strength evaluation. In this paper, a brief description on the proposed TBM NAS as well as the key components is presented, and the integration challenges of TBM NAS are outlined.

ASA24-Australia

Science.gov (United States)

The Australian project, led by Associate Professor Sarah McNaughton of The Institute for Nutrition and Physical Activity (IPAN) at Deakin University, brought together 5 national institutions with major research programs in nutrition.

Multi-group transport methods for high-resolution neutron activation analysis

International Nuclear Information System (INIS)

Burns, K. A.; Smith, L. E.; Gesh, C. J.; Shaver, M. W.

2009-01-01

The accurate and efficient simulation of coupled neutron-photon problems is necessary for several important radiation detection applications. Examples include the detection of nuclear threats concealed in cargo containers and prompt gamma neutron activation analysis for nondestructive determination of elemental composition of unknown samples. In these applications, high-resolution gamma-ray spectrometers are used to preserve as much information as possible about the emitted photon flux, which consists of both continuum and characteristic gamma rays with discrete energies. Monte Carlo transport is the most commonly used modeling tool for this type of problem, but computational times for many problems can be prohibitive. This work explores the use of multi-group deterministic methods for the simulation of neutron activation problems. Central to this work is the development of a method for generating multi-group neutron-photon cross-sections in a way that separates the discrete and continuum photon emissions so that the key signatures in neutron activation analysis (i.e., the characteristic line energies) are preserved. The mechanics of the cross-section preparation method are described and contrasted with standard neutron-gamma cross-section sets. These custom cross-sections are then applied to several benchmark problems. Multi-group results for neutron and photon flux are compared to MCNP results. Finally, calculated responses of high-resolution spectrometers are compared. Preliminary findings show promising results when compared to MCNP. A detailed discussion of the potential benefits and shortcomings of the multi-group-based approach, in terms of accuracy, and computational efficiency, is provided. (authors)

Practical considerations in instrumental neutron activation analysis

International Nuclear Information System (INIS)

Ahmad, N.

2001-01-01

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

Neutron activation analysis of geological material

International Nuclear Information System (INIS)

Greef, G.J.

1977-05-01

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

Progress in small angle neutron scattering activities in Malaysia

International Nuclear Information System (INIS)

Mohamed, Abudl Aziz Bin

2000-01-01

Research activities by use of small angle neutron scattering in Malaysia are briefly reported. Scattered neutron data are displayed in two or three-dimensional isometric view by the data acquisition system. Visual Basic is utilized for data acquisition and MathCad for data processing and analyses. (Y. Kazumata)

Progress in small angle neutron scattering activities in Malaysia

Energy Technology Data Exchange (ETDEWEB)

Mohamed, Abudl Aziz Bin [Industrial Technology Division, Malaysian Institute for Nuclear Technology Research (MINT) (Indonesia)

2000-10-01

Research activities by use of small angle neutron scattering in Malaysia are briefly reported. Scattered neutron data are displayed in two or three-dimensional isometric view by the data acquisition system. Visual Basic is utilized for data acquisition and MathCad for data processing and analyses. (Y. Kazumata)

General principles of neutron activation analysis

International Nuclear Information System (INIS)

Dostal, J.; Elson, C.

1980-01-01

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

Determination of average activating thermal neutron flux in bulk samples

International Nuclear Information System (INIS)

Doczi, R.; Csikai, J.; Doczi, R.; Csikai, J.; Hassan, F. M.; Ali, M.A.

2004-01-01

A previous method used for the determination of the average neutron flux within bulky samples has been applied for the measurements of hydrogen contents of different samples. An analytical function is given for the description of the correlation between the activity of Dy foils and the hydrogen concentrations. Results obtained by the activation and the thermal neutron reflection methods are compared

Neutron activation analysis for environmental sample in Thailand

International Nuclear Information System (INIS)

Busamongkol, Arporn; Nouchpramool, Sunun; Bunprapob, Supamatthree; Sumitra, Tatchai

2003-01-01

Neutron Activation Analysis has been applied for the trace elements analysis in environmental samples. Thirty three samples of airborne particulate were collected every week at Ongkharak Nuclear Research Center (ONRC) during the period of June 1998 to March 1999. The Ti, I, Mg, Na, V, K, Cl, Al, Mn, Ca, As, Sm, Sb, Br, La, Ce, Th, Cr, Cs, Sc, Rb, Fe, Zn and Co were analyzed by Neutron Activation Analysis utilizing 2 MW TRIGA MARK III research reactor. The certified reference materials 1632a and 1633a from National Bureau of Standard were select as standard. (author)

Evaluation of new pharmaceuticals using in vivo neutron inelastic scattering and neutron activation analysis

International Nuclear Information System (INIS)

Kehayias, J.J.

2000-01-01

Nutritional status of patients can be evaluated by monitoring changes in body composition, including depletion of protein and muscle, adipose tissue distribution and changes in hydration status, bone or cell mass. Fast neutron activation (for N and P) and neutron inelastic scattering (for C and O) are used to assess in vivo elements characteristic of specific body compartments. The fast neutrons are produced with a sealed deuterium-tritium (D-T) neutron generator. This method provides the most direct assessment of body composition. Non-bone phosphorus for muscle is measured by the 31 P(n,α) 28 Al reaction, and nitrogen for protein via the (n,2n) fast neutron reaction. Inelastic neutron scattering is used for the measurement of total body carbon and oxygen. Carbon is used to derive body fat, after subtracting carbon contributions due to protein, bone and glycogen. Carbon-to-oxygen (C/O) ratio is used to measure distribution of fat and lean tissue in the body and to monitor small changes of lean mass and its quality. In addition to evaluating the efficacy of new treatments, the system is used to study the mechanisms of lean tissue depletion with aging and to investigate methods for preserving function and quality of life in the elderly. (author)

Analysis by neutronic activation of the active principles of MIBI

International Nuclear Information System (INIS)

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

1997-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-03-01

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

Current studies of biological materials using instrumental and radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Fardy, J.J.; McOrist, G.D.; Farrar, Y.J.

1985-01-01

Instrumental neutron activation analysis still remains the preferred option when analysing the trace element distribution in a wide rage of materials by neutron activation analysis. However, when lower limits of detection are required or major interferences reduce the effectiveness of this technique, radiochemical neutron activation analysis is applied. This paper examines the current use of both methods and the development of rapid radiochemical techniques for analysis of the biological materials, hair, cow's milk, human's milk, milk powder, blood and blood serum

A novel method for active fissile mass estimation with a pulsed neutron source

International Nuclear Information System (INIS)

Dubi, C.; Ridnik, T.; Israelashvili, I.; Pedersen, B.

2013-01-01

Neutron interrogation facilities for mass evaluation of Special Nuclear Materials (SNM) samples are divided into two main categories: passive interrogation, where all neutron detections are due to spontaneous events, and active interrogation, where fissions are induced on the tested material by an external neutron source. While active methods are, in general, faster and more effective, their analysis is much harder to carry out. In the paper, we will introduce a new formalism for analyzing the detection signal generated by a pulsed source active interrogation facility. The analysis is aimed to distinct between fission neutrons from the main neutron source in the system, and the surrounding “neutron noise”. In particular, we derive analytic expressions for the first three central moments of the number of detections in a given time interval, in terms of the different neutron sources. While the method depends on exactly the same physical assumptions as known models, the simplicity of the suggested formalism allows us to take into account the variance of the external neutron source—an effect that was so far neglected

A novel method for active fissile mass estimation with a pulsed neutron source

Energy Technology Data Exchange (ETDEWEB)

Dubi, C., E-mail: chendb331@gmail.com [Physics Department, Nuclear Research Center of the Negev, POB 9001, Beer Sheva (Israel); Ridnik, T.; Israelashvili, I. [Physics Department, Nuclear Research Center of the Negev, POB 9001, Beer Sheva (Israel); Pedersen, B. [Nuclear Security Unit, Institute for Transuranium Elements, Via E. Fermi, 2749 JRC, Ispra (Italy)

2013-07-01

Neutron interrogation facilities for mass evaluation of Special Nuclear Materials (SNM) samples are divided into two main categories: passive interrogation, where all neutron detections are due to spontaneous events, and active interrogation, where fissions are induced on the tested material by an external neutron source. While active methods are, in general, faster and more effective, their analysis is much harder to carry out. In the paper, we will introduce a new formalism for analyzing the detection signal generated by a pulsed source active interrogation facility. The analysis is aimed to distinct between fission neutrons from the main neutron source in the system, and the surrounding “neutron noise”. In particular, we derive analytic expressions for the first three central moments of the number of detections in a given time interval, in terms of the different neutron sources. While the method depends on exactly the same physical assumptions as known models, the simplicity of the suggested formalism allows us to take into account the variance of the external neutron source—an effect that was so far neglected.

Neutron activation analysis of high-purity iron in comparison with chemical analysis

International Nuclear Information System (INIS)

Kinomura, Atsushi; Horino, Yuji; Takaki, Seiichi; Abiko, Kenji

2000-01-01

Neutron activation analysis of iron samples of three different purity levels has been performed and compared with chemical analysis for 30 metallic and metalloid impurity elements. The concentration of As, Cl, Cu, Sb and V detected by neutron activation analysis was mostly in agreement with that obtained by chemical analysis. The sensitivity limits of neutron activation analysis of three kinds of iron samples were calculated and found to be reasonable compared with measured values or detection limits of chemical analysis; however, most of them were above the detection limits of chemical analysis. Graphite-shielded irradiation to suppress fast neutron reactions was effective for Mn analysis without decreasing sensitivity to the other impurity elements. (author)

Application of neutron activation analysis

International Nuclear Information System (INIS)

Dybczynski, R.

2001-01-01

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

A novel track density measurement method by thermal neutron activation of DYECETs

International Nuclear Information System (INIS)

Sohrabi, M.; Mahdi, Sh.

1995-01-01

A novel track density evaluation method based on thermal neutron activation of some elements of dyed electrochemically etched tracks (DYECETs) of charged particles in detectors like polycarbonate (PC) followed by measurements of gamma activity of the activated detectors is introduced. In this method, the tracks of charged particles like fast neutron-induced recoils in PC detectors were electrochemically etched, dyed by ''QuicDYECET'' methods as recently introduced by us, activated by thermal neutrons and counted for gamma activity determination to be correlated with track density. The activities of elements such as bromine-82 ( 82 Br) and sodium-24 ( 24 Na) on dyes such as Eosin Yellowish, Eosin Bluish, etc. determined by a hyper-pure germanium detector, were found to be in good correlation with DYECET density and thus particle fluence or dose. The effects of different types of dyes and their elements, dye concentration, neutron fluences and ECE durations on the DYECET density responses were studied. This new development is a method of scientific interest, potentially possessing some interesting features, as an alternative method for ECE track density determination using a gamma activity measuring system. It also has the drawback of being applicable only in centres having thermal neutron facilities. The results of the above studies are presented and discussed. (Author)

Fast neutron activating detectors for pulsed flow measurements

International Nuclear Information System (INIS)

Dyatlov, V.D.; Kunaev, G.T.; Popytaev, A.N.; Cheremukhov, B.V.

1979-01-01

The requirements to the activation detectors of the pulsed flows of the fast neutrons are considered; the criteria of optimum measurement time, geometrical moderator sizes and radioactive detector element properties have been obtained. On their analysis parameter selection has been carried out. The neutron detector to register the short pulses has been designed and calibrated. The ways of further increase of sensitivity and efficiency of such detectors are discussed

Instrumental neutron activation determination of gold in mineral raw materials using a californium neutron source

International Nuclear Information System (INIS)

Shilo, N.A.; Ippolitov, E.G.; Ivanenko, V.V.; Kustov, B.N.; Zheleznov, V.V.; Aristov, G.N.; Kovalenko, V.V.; Kondrat'ev, N.B.

1983-01-01

A facility using a californium neutron source and a method for the neutron activation analysis of gold were developed. The sensitivity of the determination is 0.1 g/t. The causes of random and systematic errors have been studied. It is concluded that in prospection and evaluation of gold ore deposists, the traditional test tube analysis for gold may be replaced with the developed method. (author)

Applicability of the activation analysis with prompt neutron in medicine

International Nuclear Information System (INIS)

Yaghubian-Malhami, R.

1975-04-01

The concentrations of boron and cadmium in the human body are of great importance in medicine. The author determined their concentration by prompt neutron activation analysis in aqueous solutions and in urine. The results show that this technique may be used in medical diagnosis. The author discusses the qualities and the applicability of delayed and prompt neutron activation analysis in biology and medicine. (C.R.)

Neutron transport calculation for Activation Evaluation for Decommissioning of PET cyclotron Facility

Science.gov (United States)

Nobuhara, Fumiyoshi; Kuroyanagi, Makoto; Masumoto, Kazuyoshi; Nakamura, Hajime; Toyoda, Akihiro; Takahashi, Katsuhiko

2017-09-01

In order to evaluate the state of activation in a cyclotron facility used for the radioisotope production of PET diagnostics, we measured the neutron flux by using gold foils and TLDs. Then, the spatial distribution of neutrons and induced activity inside the cyclotron vault were simulated with the Monte Calro calculation code for neutron transport and DCHAIN-SP for activation calculation. The calculated results are in good agreement with measured values within factor 3. Therefore, the adaption of the advanced evaluation procedure for activation level is proved to be important for the planning of decommissioning of these facilities.

Development and simulation of various methods for neutron activation analysis

International Nuclear Information System (INIS)

Otgooloi, B.

1993-01-01

Simple methods for neutron activation analysis have been developed. The results on the studies of installation for determination of fluorine in fluorite ores directly on the lorry by fast neutron activation analysis have been shown. Nitrogen in organic materials was shown by N 14 and N 15 activation. The description of the new equipment 'FLUORITE' for fluorate factory have been shortly given. Pu and Be isotope in organic materials, including in wheat, was measured. 25 figs, 19 tabs. (Author, Translated by J.U)

Precision of neutron activation analysis for environmental biological materials

International Nuclear Information System (INIS)

Hamaguchi, Hiroshi; Iwata, Shiro; Koyama, Mutsuo; Sasajima, Kazuhisa; Numata, Yuichi.

1977-01-01

Between 1973 and 1974 a special committee ''Research on the application of neutron activation analysis to the environmental samples'' had been organized at the Research Reactor Institute, Kyoto University. Eleven research groups composed mainly of the committee members cooperated in the intercomparison programme of the reactor neutron activation analysis of NBS standard reference material, 1571 Orchard Leaves and 1577 Bovine Liver. Five different type of reactors were used for the neutron irradiation; i.e. KUR reactor of the Research Reactor Institute, Kyoto University, TRIGA MARK II reactor of the Institute for Atomic Energy, Rikkyo University, and JRR-2, JRR-3, JRR-4 reactor of Japan Atomic Energy Research Institute. Analyses were performed mainly by instrumental method. Precision of the analysis of 23 elements in Orchard Leaves and 13 elements in Bovine Liver presented by the different research groups was shown in table 4 and 5, respectively. The coefficient of variation for these elements was from several to -- 30 percent. Averages given to these elements agreed well with the NBS certified or reference values. Thus, from the practical point of view for the routine multielement analysis of environmental samples, the validity of the instrumental neutron activation technique for this purpose has been proved. (auth.)

Determination of copper in some Myanmar indigenous medicines by neutron activation analysis

International Nuclear Information System (INIS)

Myint-U; Kyi Kyi San

1994-01-01

Copper was determined in two Myanmar indigenous medicines by neutron activation analysis using an Am(Be) radionuclide neutron source. The activity of 511 keV peak of the 64 Cu was measured. (author) 2 refs.; 2 tabs

Mercury mass measurement in fluorescent lamps via neutron activation analysis

International Nuclear Information System (INIS)

Viererbl, L.; Vinš, M.; Lahodová, Z.; Fuksa, A.; Kučera, J.; Koleška, M.; Voljanskij, A.

2015-01-01

Mercury is an essential component of fluorescent lamps. Not all fluorescent lamps are recycled, resulting in contamination of the environment with toxic mercury, making measurement of the mercury mass used in fluorescent lamps important. Mercury mass measurement of lamps via instrumental neutron activation analysis (NAA) was tested under various conditions in the LVR-15 research reactor. Fluorescent lamps were irradiated in different positions in vertical irradiation channels and a horizontal channel in neutron fields with total fluence rates from 3×10 8 cm −2 s −1 to 10 14 cm −2 s −1 . The 202 Hg(n,γ) 203 Hg nuclear reaction was used for mercury mass evaluation. Activities of 203 Hg and others induced radionuclides were measured via gamma spectrometry with an HPGe detector at various times after irradiation. Standards containing an Hg 2 Cl 2 compound were used to determine mercury mass. Problems arise from the presence of elements with a large effective cross section in luminescent material (europium, antimony and gadolinium) and glass (boron). The paper describes optimization of the NAA procedure in the LVR-15 research reactor with particular attention to influence of neutron self-absorption in fluorescent lamps. - Highlights: • Mercury is an essential component of fluorescent lamps. • Fluorescent lamps were irradiated in neutron fields in research reactor. • 203 Hg induced radionuclide activity was measured using gamma spectrometry. • Mercury mass in fluorescent lamps can be measured by neutron activation analysis.

Neutron activation analysis for uranium and associated elements

International Nuclear Information System (INIS)

Bowman, W.W.

1977-01-01

The samples obtained by the Savannah River Laboratory as part of the National Uranium Resource Evaluation program are activated in the intense neutron flux from a Savannah River Plant production reactor. A pilot-scale facility was installed at the reactor site to provide analyses of samples through the initial phase of the program and to develop design data for a full-scale facility. Sediments are analyzed by direct activation of 0.5-g samples. However, to analyze ground or surface water samples, mineral elements from 1-liter samples are concentrated on ion exchange resin and then approximately 5-g samples of resin are activated. Uranium concentration is determined by counting neutrons emitted from specific short-lived products of fission induced in 235 U by the primary neutron flux. Repetitive short cycles of irradiation and counting permit detection and determination of <0.1 μg of uranium. Elements associated with uranium are determined by spectral analysis of the gamma ray activities induced by the cyclic and subsequent longer irradiations. The pilot facility consists of four irradiation positions (plus 2 spare positions), a sample loader and unloader, and counting stations with neutron and gamma ray detectors, all interconnected with a pneumatic sample transport system. A computer controls both the transport system and the data acquisition devices. Gamma ray counting data are stored on magnetic tape for further processing by a large central computer. Facility hardware and software are described. Repetitive analyses of standards have shown an accuracy within +-10% for uranium values and within +-25% for associated elements. A quality assurance program has been developed to maintain these levels of reliability

Applications of neutron activation analysis in industry

International Nuclear Information System (INIS)

Zaini Hamzah.

1985-01-01

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

Estimated neutron-activation data for TFTR. Part II. Biological dose rate from sample-materials activation

International Nuclear Information System (INIS)

Ku, L.; Kolibal, J.G.

1982-06-01

The neutron induced material activation dose rate data are summarized for the TFTR operation. This report marks the completion of the second phase of the systematic study of the activation problem on the TFTR. The estimations of the neutron induced activation dose rates were made for spherical and slab objects, based on a point kernel method, for a wide range of materials. The dose rates as a function of cooling time for standard samples are presented for a number of typical neutron spectrum expected during TFTR DD and DT operations. The factors which account for the variations of the pulsing history, the characteristic size of the object and the distance of observation relative to the standard samples are also presented

Determination of copper in some Myanmar indigenous medicines by neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Myint-U,; San, Kyi Kyi [Yangon Univ. (Myanmar). Dept. of Chemistry

1994-09-15

Copper was determined in two Myanmar indigenous medicines by neutron activation analysis using an Am(Be) radionuclide neutron source. The activity of 511 keV peak of the [sup 64]Cu was measured. (author) 2 refs.; 2 tabs.

Partial neutron capture cross sections of actinides using cold neutron prompt gamma activation analysis

International Nuclear Information System (INIS)

Genreith, Christoph

2015-01-01

Nuclear waste needs to be characterized for its safe handling and storage. In particular long-lived actinides render the waste characterization challenging. The results described in this thesis demonstrate that Prompt Gamma Neutron Activation Analysis (PGAA) with cold neutrons is a reliable tool for the non-destructive analysis of actinides. Nuclear data required for an accurate identification and quantification of actinides was acquired. Therefore, a sample design suitable for accurate and precise measurements of prompt γ-ray energies and partial cross sections of long-lived actinides at existing PGAA facilities was presented. Using the developed sample design the fundamental prompt γ-ray data on 237 Np, 241 Am and 242 Pu were measured. The data were validated by repetitive analysis of different samples at two individual irradiation and counting facilities - the BRR in Budapest and the FRM II in Garching near Munich. Employing cold neutrons, resonance neutron capture by low energetic resonances was avoided during the experiments. This is an improvement over older neutron activation based works at thermal reactor neutron energies. 152 prompt γ-rays of 237 Np were identified, as well as 19 of 241 Am, and 127 prompt γ-rays of 242 Pu. In all cases, both high and lower energetic prompt γ-rays were identified. The most intense line of 237 Np was observed at an energy of E γ =182.82(10) keV associated with a partial capture cross section of σ γ =22.06(39) b. The most intense prompt γ-ray lines of 241 Am and of 242 Pu were observed at E γ =154.72(7) keV with σ γ =72.80(252) b and E γ =287.69(8) keV with σ γ =7.07(12) b, respectively. The measurements described in this thesis provide the first reported quantifications on partial radiative capture cross sections for 237 Np, 241 Am and 242 Pu measured simultaneously over the large energy range from 45 keV to 12 MeV. Detailed uncertainty assessments were performed and the validity of the given uncertainties was

SWAN - Detection of explosives by means of fast neutron activation analysis

International Nuclear Information System (INIS)

Gierlik, M.; Borsuk, S.; Guzik, Z.; Iwanowska, J.; Kaźmierczak, Ł.; Korolczuk, S.; Kozłowski, T.; Krakowski, T.; Marcinkowski, R.; Swiderski, L.; Szeptycka, M.; Szewiński, J.; Urban, A.

2016-01-01

In this work we report on SWAN, the experimental, portable device for explosives detection. The device was created as part of the EU Structural Funds Project “Accelerators & Detectors” (POIG.01.01.02-14-012/08-00), with the goal to increase beneficiary's expertise and competencies in the field of neutron activation analysis. Previous experiences and budged limitations lead toward a less advanced design based on fast neutron interactions and unsophisticated data analysis with the emphasis on the latest gamma detection and spectrometry solutions. The final device has been designed as a portable, fast neutron activation analyzer, with the software optimized for detection of carbon, nitrogen and oxygen. SWAN's performance in the role of explosives detector is elaborated in this paper. We demonstrate that the unique features offered by neutron activation analysis might not be impressive enough when confronted with practical demands and expectations of a generic homeland security customer.

Utilization and facility of neutron activation analysis in HANARO research reactor

International Nuclear Information System (INIS)

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

1998-01-01

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

Use of research reactors for neutron activation analysis. Report of an advisory group meeting

International Nuclear Information System (INIS)

2001-04-01

Neutron activation analysis (NAA) is an analytical technique based on the measurement of characteristic radiation from radionuclides formed directly or indirectly by neutron irradiation of the material of interest. In the last three decades, neutron activation analysis has been found to be extremely useful in the determination of trace and minor elements in many disciplines. These include environmental analysis applications, nutritional and health related studies, geological as well as material sciences. The most suitable source of neutrons for NAA is a research reactor. There are several application fields in which NAA has a superior position compared to other analytical methods, and there are good prospects in developing countries for long term growth. Therefore, the IAEA is making concerted efforts to promote neutron activation analysis and at the same time to assist developing Member States in better utilization of their research reactors. The purpose of the meeting was to discuss the benefits and the role of NAA in applications and research areas that may contribute towards improving utilization of research reactors. The participants focused on five specific topics: (1) Current trends in NAA; (2) The role of NAA compared to other methods of chemical analysis; (3) How to increase the number of NAA users through interaction with industries, research institutes, universities and medical institutions; (4) How to reduce costs and to maintain quality and reliability; (5) NAA using low power research reactors. Neutron activation analysis in its various forms is still active and there are good prospects in developing countries for long-term growth. This can be achieved by a more effective use of existing irradiation and counting facilities, a better end-user focus, and perhaps marginal improvements in equipment and techniques. Therefore, it is recommended that the Member States provide financial and other assistance to enhance the effectiveness of their laboratories

Opportunities for innovation in neutron activation analysis

International Nuclear Information System (INIS)

Peter Bode

2012-01-01

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

Neutron activation analysis for noble metals in matte leach residues

International Nuclear Information System (INIS)

Hart, R.J.

1978-01-01

The development of the neutron activation analysis technique as a method for rapid and precise determinations of platinum group metals in matte leach residues depends on obtaining a method for effecting complete and homogeneous sample dilution. A simple method for solid dilution of metal samples is outlined in this study, which provided a basis for the accurate determination of all the noble metals by the Neutron Activation Analysis technique

Calibration of a detector by activation with a continuous neutron source used as a transfer standard for measuring pulsed neutron beams

International Nuclear Information System (INIS)

Moreno, Jose; Silva, Patricio; Birstein, Lipo; Soto, Leopoldo

2002-01-01

This paper presents a method for calibrating activation detectors. These detectors will be used as transfer standard in measuring neutron fluxes produced by pulsed plasma sources. A standard neutron source is used as a secondary standard. The activation detector is being shielded in order to substantially reduce detection of gamma emission coming from the source. The detector's calibration factor is obtained by considering also the standard neutron source as a free source of gamma radiation so that the measurements can be done without quickly withdrawing the neutron source as it is usually done. This will substantially simplify the traditionally established method (JM)

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

International Nuclear Information System (INIS)

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

2000-01-01

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

Fast neutron activation analysis at Texas A and M University

International Nuclear Information System (INIS)

James, W.D.

1997-01-01

Fast neutron generators are used at Texas A and M University to provide a supply of high energy neutrons for nuclear analytical measurements. A series of neutron activation analysis procedures have been developed for determining various major, minor and trace constituents in a variety of materials. These procedures are primarily developed to compliment our reactor based NAA program, thereby expanding the list of determinable elements to include those difficult or impossible to measure using thermal neutrons. A few typical methods are discussed. The unique implementation of the methodologies at Texas A and M are explained. (author)

Current status of neutron activation analysis in HANARO Research Reactor

International Nuclear Information System (INIS)

Chung, Yong Sam; Moon, Jong Hwa; Sohn, Jae Min

2003-01-01

The facilities for neutron activation analysis in the HANARO (Hi-flux Advanced Neutron Application Research Reactor) are described and the main applications of NAA (Neutron Activation Analysis) are reviewed. The sample irradiation tube, automatic and manual pneumatic transfer system were installed at three irradiation holes of HANARO at the end of 1995. The performance of the NAA facility was examined to identify the characteristics of the tube transfer system, irradiation sites and custom-made polyethylene irradiation capsule. The available thermal neutron fluxes at irradiation sites are in the range of 3 x 10 13 - 1 x 10 14 n/cm 2 ·s and cadmium ratios are in 15 - 250. For an automatic sample changer for gamma-ray counting, a domestic product was designed and manufactured. An integrated computer program (Labview) to analyse the content was developed. In 2001, PGNAA (Prompt Gamma Neutron Activation Analysis) facility has been installed using a diffracted neutron beam of ST1. NAA has been applied in the trace component analysis of nuclear, geological, biological, environmental and high purity materials, and various polymers for research and development. The improvement of analytical procedures and establishment of an analytical quality control and assurance system were studied. Applied research and development for the environment, industry and human health by NAA and its standardization were carried out. For the application of the KOLAS (Korea Laboratory Accreditation Scheme), evaluation of measurement uncertainty and proficiency testing of reference materials were performed. Also to verify the reliability and to validate analytical results, intercomparison studies between laboratories were carried out. (author)

Current status of neutron activation analysis in HANARO Research Reactor

Energy Technology Data Exchange (ETDEWEB)

Chung, Yong Sam; Moon, Jong Hwa; Sohn, Jae Min [Korea Atomic Energy Research Institute, Daejeon (Korea)

2003-03-01

The facilities for neutron activation analysis in the HANARO (Hi-flux Advanced Neutron Application Research Reactor) are described and the main applications of NAA (Neutron Activation Analysis) are reviewed. The sample irradiation tube, automatic and manual pneumatic transfer system were installed at three irradiation holes of HANARO at the end of 1995. The performance of the NAA facility was examined to identify the characteristics of the tube transfer system, irradiation sites and custom-made polyethylene irradiation capsule. The available thermal neutron fluxes at irradiation sites are in the range of 3 x 10{sup 13} - 1 x 10{sup 14} n/cm{sup 2}{center_dot}s and cadmium ratios are in 15 - 250. For an automatic sample changer for gamma-ray counting, a domestic product was designed and manufactured. An integrated computer program (Labview) to analyse the content was developed. In 2001, PGNAA (Prompt Gamma Neutron Activation Analysis) facility has been installed using a diffracted neutron beam of ST1. NAA has been applied in the trace component analysis of nuclear, geological, biological, environmental and high purity materials, and various polymers for research and development. The improvement of analytical procedures and establishment of an analytical quality control and assurance system were studied. Applied research and development for the environment, industry and human health by NAA and its standardization were carried out. For the application of the KOLAS (Korea Laboratory Accreditation Scheme), evaluation of measurement uncertainty and proficiency testing of reference materials were performed. Also to verify the reliability and to validate analytical results, intercomparison studies between laboratories were carried out. (author)

Toroidal deuteron accelerator for Mo-98 neutron activation

Energy Technology Data Exchange (ETDEWEB)

Araujo, Wagner L., E-mail: wagner.leite@ifnmg.edu.br, E-mail: tprcampos@pq.cnpq.br [Instituto Federal do Norte de Minas Gerais (IFN-MG), Montes Claros, MG (Brazil); Campos, Tarcisio P.R. Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

2017-07-01

The radionuclide Tc-{sup 99m} is the most useful radioisotope in nuclear medicine. It can be produced by the Mo-99 beta minus decay. Mo-99 has often been produced in a high- flux nuclear reactor through radioactive neutron capture reactions on Mo-98. The present paper provides a preliminary design of a toroidal transmutation system (TTS) based on a toroidal compact deuteron accelerator, which can provide the Mo-98 transmutation into Mo-99. This system is essentially composed of a multi-aperture plasma electrode and a target, submitted to 180 kV, where a positive deuteron beam is accelerated toward a titanium-target loaded with deuterium in which nuclear d-d fusion reactions are induced. The Particle Studio package of the Computer Simulation Technology (CST) software was applied to design, simulate and optimize the deuteron beam on the target. MCNP code provided to neutronic analysis. Based on electromagnetic and neutronic simulations, the neutron yield and reaction rates were estimated. The simulated data allowed appraising the Mo-99 activity. A TTS, in a specific configuration, could produce a total deuterium current of 1.6 A at the target and a neutron yield of 10{sup 13} n.s{sup -1}. In a arrangement of 30 column samples, TTS provides 230 mCi s{sup -1} Mo{sup 99} in each column, which represents 80% of Tc-99m in secular equilibrium. As conclusion, the system holds potential for generating Mo-99 and Tc-99m in a suitable activity in secular equilibrium. (author)

Toroidal deuteron accelerator for Mo-98 neutron activation

International Nuclear Information System (INIS)

Araujo, Wagner L.; Campos, Tarcisio P.R. Universidade Federal de Minas Gerais

2017-01-01

The radionuclide Tc- 99m is the most useful radioisotope in nuclear medicine. It can be produced by the Mo-99 beta minus decay. Mo-99 has often been produced in a high- flux nuclear reactor through radioactive neutron capture reactions on Mo-98. The present paper provides a preliminary design of a toroidal transmutation system (TTS) based on a toroidal compact deuteron accelerator, which can provide the Mo-98 transmutation into Mo-99. This system is essentially composed of a multi-aperture plasma electrode and a target, submitted to 180 kV, where a positive deuteron beam is accelerated toward a titanium-target loaded with deuterium in which nuclear d-d fusion reactions are induced. The Particle Studio package of the Computer Simulation Technology (CST) software was applied to design, simulate and optimize the deuteron beam on the target. MCNP code provided to neutronic analysis. Based on electromagnetic and neutronic simulations, the neutron yield and reaction rates were estimated. The simulated data allowed appraising the Mo-99 activity. A TTS, in a specific configuration, could produce a total deuterium current of 1.6 A at the target and a neutron yield of 10 13 n.s -1 . In a arrangement of 30 column samples, TTS provides 230 mCi s -1 Mo 99 in each column, which represents 80% of Tc-99m in secular equilibrium. As conclusion, the system holds potential for generating Mo-99 and Tc-99m in a suitable activity in secular equilibrium. (author)

Neutron activation analysis

International Nuclear Information System (INIS)

Borsaru, M.; Eisler, P.L.

1981-01-01

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

Data reduction for a high-throughput neutron activation analysis system

International Nuclear Information System (INIS)

Bowman, W.W.

1979-01-01

To analyze samples collected as part of a geochemical survey for the National Uranium Resource Evaluation program, Savannah River Laboratory has installed a high-throughput neutron activation analysis system. As part of that system, computer programs have been developed to reduce raw data to elemental concentrations in two steps. Program RAGS reduces gamma-ray spectra to lists of photopeak energies, peak areas, and statistical errors. Program RICHES determines the elemental concentrations from photopeak and delayed-neutron data, detector efficiencies, analysis parameters (neutron flux and activation, decay, and counting times), and spectrometric and cross-section data from libraries. Both programs have been streamlined for on-line operation with a minicomputer, each requiring approx. 64 kbytes of core. 3 tables

Studies on airborne dust particles by neutron activation analysis

International Nuclear Information System (INIS)

Aoki, Atsushi; Ishii, Taka; Tomiyama, Tsuyoshi; Yamamoto, Isao.

1974-01-01

Neutron activation analysis was performed on the airborne dust particles collected at six places with different contaminating circumstances in Kyoto city and the suburbs of Okayama city, using an open type low volume air sampler with a membrance filter attached. Radioactivation by neutrons was performed with the reactor in the Research Reactor Institute of Kyoto University. Short half-life nuclides activated by thermal neutrons were measured. The concentration of airborne dust was usually high in November and December, while Na, Mn, K, etc. probably owing to soil origin showed similar seasonal change to the dust particles, as expected. The concentrations Cl and Br were in proportion to traffic volume, and it was considered to be caused by the exhaust gas from cars. Zn, V. et. were thick in factory areas, which seemed to show the relationship with oil fuel consumption. (Kobatake, H.)

ACTIV87 Fast neutron activation cross section file 1987

International Nuclear Information System (INIS)

Manokhin, V.N.; Pashchenko, A.B.; Plyaskin, V.I.; Bychkov, V.M.; Pronyaev, V.G.; Schwerer, O.

1989-10-01

This document summarizes the content of the Fast Neutron Activation Cross Section File based on data from different evaluated data libraries and individual evaluations in ENDF/B-5 format. The entire file or selective retrievals from it are available on magnetic tape, free of charge, from the IAEA Nuclear Data Section. (author)

Electromagnetic activity of a pulsating paramagnetic neutron star

International Nuclear Information System (INIS)

Bastrukov, S.I.; Podgainy, D.V.; Yang, J.; Weber, F.

2002-01-01

The fact that neutron star matter possesses the capability of maintaining a highly intense magnetic field has been and still is among the most debatable issues in pulsar astrophysics. Over the years, there were several independent suggestions that the dominant source of pulsar magnetism is either the field-induced or the spontaneous magnetic polarization of the baryon material. The Pauli paramagnetism of degenerate neutron matter is one of the plausible and comprehensive mechanisms of the magnetic ordering of neutron magnetic moments, promoted by a seed magnetic field inherited by the neutron star from a massive progenitor and amplified by its implosive contraction due to the magnetic flux conservation. Adhering to this attitude and based on the equations of magnetoelastic dynamics underlying continuum mechanics of single-axis magnetic insulators, we investigate electrodynamics of a paramagnetic neutron star undergoing nonradial pulsations. We show that the suggested approach regains a recent finding of Akhiezer et al. that the spin-polarized neutron matter can transmit perturbations by low-frequency transverse magnetoelastic waves. We found that nonradial torsional magnetoelastic pulsations of a paramagnetic neutron star can serve as a powerful generator of a highly intense electric field producing the magnetospheric polarization charge whose acceleration along the open magnetic field lines leads to the synchrotron and curvature radiation. Analytic and numerical estimates for periods of nonradial torsional magnetoelastic modes are presented and are followed by a discussion of their possible manifestation in currently monitored activity of pulsars and magnetars

SWAN - Detection of explosives by means of fast neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Gierlik, M., E-mail: m.gierlik@ncbj.gov.pl; Borsuk, S.; Guzik, Z.; Iwanowska, J.; Kaźmierczak, Ł.; Korolczuk, S.; Kozłowski, T.; Krakowski, T.; Marcinkowski, R.; Swiderski, L.; Szeptycka, M.; Szewiński, J.; Urban, A.

2016-10-21

In this work we report on SWAN, the experimental, portable device for explosives detection. The device was created as part of the EU Structural Funds Project “Accelerators & Detectors” (POIG.01.01.02-14-012/08-00), with the goal to increase beneficiary's expertise and competencies in the field of neutron activation analysis. Previous experiences and budged limitations lead toward a less advanced design based on fast neutron interactions and unsophisticated data analysis with the emphasis on the latest gamma detection and spectrometry solutions. The final device has been designed as a portable, fast neutron activation analyzer, with the software optimized for detection of carbon, nitrogen and oxygen. SWAN's performance in the role of explosives detector is elaborated in this paper. We demonstrate that the unique features offered by neutron activation analysis might not be impressive enough when confronted with practical demands and expectations of a generic homeland security customer.

Utilization and facility of neutron activation analysis in HANARO research reactor

Energy Technology Data Exchange (ETDEWEB)

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

1998-07-01

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

Gamma-ray-spectroscopy following high-flux 14-MeV neutron activation

International Nuclear Information System (INIS)

Williams, R.E.

1981-01-01

The Rotating Target Neutron Source (RTNS-I), a high-intensity source of 14-MeV neutrons at the Lawrence Livermore National Laboratory (LLNL), has been used for applications in activation analysis, inertial-confinement-fusion diagnostic development, and fission decay-heat studies. The fast-neutron flux from the RTNS-I is at least 50 times the maximum fluxes available from typical neutron generators, making these applications possible. Facilities and procedures necessary for gamma-ray spectroscopy of samples irradiated at the RTNS-I were developed

Gamma-ray-spectroscopy following high-flux 14-MeV neutron activation

Energy Technology Data Exchange (ETDEWEB)

Williams, R.E.

1981-10-12

The Rotating Target Neutron Source (RTNS-I), a high-intensity source of 14-MeV neutrons at the Lawrence Livermore National Laboratory (LLNL), has been used for applications in activation analysis, inertial-confinement-fusion diagnostic development, and fission decay-heat studies. The fast-neutron flux from the RTNS-I is at least 50 times the maximum fluxes available from typical neutron generators, making these applications possible. Facilities and procedures necessary for gamma-ray spectroscopy of samples irradiated at the RTNS-I were developed.

Design of active-neutron fuel rod scanner

International Nuclear Information System (INIS)

Griffith, G.W.; Menlove, H.O.

1996-01-01

An active-neutron fuel rod scanner has been designed for the assay of fissile materials in mixed oxide fuel rods. A 252 Cf source is located at the center of the scanner very near the through hole for the fuel rods. Spontaneous fission neutrons from the californium are moderated and induce fissions within the passing fuel rod. The rod continues past a combined gamma-ray and neutron shield where delayed gamma rays above 1 MeV are detected. We used the Monte Carlo code MCNP to design the scanner and review optimum materials and geometries. An inhomogeneous beryllium, graphite, and polyethylene moderator has been designed that uses source neutrons much more efficiently than assay systems using polyethylene moderators. Layers of borated polyethylene and tungsten are used to shield the detectors. Large NaI(Tl) detectors were selected to measure the delayed gamma rays. The enrichment zones of a thermal reactor fuel pin could be measured to within 1% counting statistics for practical rod speeds. Applications of the rod scanner include accountability of fissile material for safeguards applications, quality control of the fissile content in a fuel rod, and the verification of reactivity potential for mixed oxide fuels. (orig.)

Neutron activation analysis of biological substances

International Nuclear Information System (INIS)

Ordogh, M.

1978-08-01

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

FY17 Status Report on NEAMS Neutronics Activities

Energy Technology Data Exchange (ETDEWEB)

Lee, C. H. [Argonne National Lab. (ANL), Argonne, IL (United States); Jung, Y. S. [Argonne National Lab. (ANL), Argonne, IL (United States); Smith, M. A. [Argonne National Lab. (ANL), Argonne, IL (United States)

2017-09-30

Under the U.S. DOE NEAMS program, the high-fidelity neutronics code system has been developed to support the multiphysics modeling and simulation capability named SHARP. The neutronics code system includes the high-fidelity neutronics code PROTEUS, the cross section library and preprocessing tools, the multigroup cross section generation code MC2-3, the in-house meshing generation tool, the perturbation and sensitivity analysis code PERSENT, and post-processing tools. The main objectives of the NEAMS neutronics activities in FY17 are to continue development of an advanced nodal solver in PROTEUS for use in nuclear reactor design and analysis projects, implement a simplified sub-channel based thermal-hydraulic (T/H) capability into PROTEUS to efficiently compute the thermal feedback, improve the performance of PROTEUS-MOCEX using numerical acceleration and code optimization, improve the cross section generation tools including MC2-3, and continue to perform verification and validation tests for PROTEUS.

Nondestructive neutron activation analysis of volcanic samples: Hawaii

International Nuclear Information System (INIS)

Zoller, W.H.; Finnegan, D.L.; Crowe, B.

1986-01-01

Samples of volcanic emissions have been collected between and during eruptions of both Kilauea and Mauna Loa volcanoes during the last three years. Airborne particles have been collected on Teflon filters and acidic gases on base-impregnated cellulose filters. Chemically neutral gas-phase species are collected on charcoal-coated cellulose filters. The primary analytical technique used is nondestructive neutron activation analysis, which has been used to determine the quantities of up to 35 elements on the different filters. The use of neutron activation analysis makes it possible to analyze for a wide range of elements in the different matrices used for the collection and to learn about the distribution between particles and gas phases for each of the elements

Source Correlated Prompt Neutron Activation Analysis for Material Identification and Localization

Science.gov (United States)

Canion, Bonnie; McConchie, Seth; Landsberger, Sheldon

2017-07-01

This paper investigates the energy spectrum of photon signatures from an associated particle imaging deuterium tritium (API-DT) neutron generator interrogating shielded uranium. The goal is to investigate if signatures within the energy spectrum could be used to indirectly characterize shielded uranium when the neutron signature is attenuated. By utilizing the correlated neutron cone associated with each pixel of the API-DT neutron generator, certain materials can be identified and located via source correlated spectrometry of prompt neutron activation gamma rays. An investigation is done to determine if fission neutrons induce a significant enough signature within the prompt neutron-induced gamma-ray energy spectrum in shielding material to be useful for indirect nuclear material characterization. The signature deriving from the induced fission neutrons interacting with the shielding material was slightly elevated in polyethylene-shielding depleted uranium (DU), but was more evident in some characteristic peaks from the aluminum shielding surrounding DU.

Nondestructive testing: Neutron radiography and neutron activation. (Latest citations from the INSPEC: Information services for the physics and engineering communities database). Published Search

International Nuclear Information System (INIS)

1993-08-01

The bibliography contains citations concerning the technology of neutron radiography and neutron activation for nondestructive testing of materials. The development and evaluation of neutron activation analysis and neutron diffraction examination of liquids and solids are presented. Citations also discuss nondestructive assay, verification, evaluation, and multielement analysis of biomedical, environmental, industrial, and geological materials. Nondestructive identification of chemical agents, explosives, weapons, and drugs in sealed containers are explored. (Contains a minimum of 83 citations and includes a subject term index and title list.)

Uncertainty Assessments in Fast Neutron Activation Analysis

International Nuclear Information System (INIS)

W. D. James; R. Zeisler

2000-01-01

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

Reactor neutron activation analysis for aluminium in the presence of phosphorus and silicon

International Nuclear Information System (INIS)

Mizumoto, Yoshihiko; Iwata, Shiro; Sasajima, Kazuhisa; Yoshimasu, Fumio; Yase, Yoshiro.

1984-01-01

Reactor neutron activation analysis for aluminium in samples containing phosphorus and silicon was studied. The experiments were performed by using neumatic tube of the Kyoto University Reactor (KUR). At first, the ratios of the 28 Al activity produced from 27 Al(n, γ) 28 Al reaction by thermal neutrons to that from 31 P(n, α) 28 Al reaction by fast neutrons, and to that from 28 Si(n, p) 28 Al reaction were measured by γ-ray spectrometry. With a ratio of about 5 for the thermal to fast neutron flux of KUR, the ratio of the 28 Al activity from aluminium to that from phosphorus was to be 812 +- 7, and to that from silicon 282 +- 3. Secondly, the contributions of 28 Al activities from phosphorus and silicon and the determination limit of aluminium were calculated for various parameters, such as fast neutron flux, thermal to fast neutron flux ratio, amounts of phosphorus and silicon, etc. Thirdly, on the basis of these results, aluminium contents in spinal cords and brains of amyotrophic lateral sclerosis, Parkinsonism-dementia complex and control cases were determined. (author)

A file of reference data for multiple-element neutron activation analysis

International Nuclear Information System (INIS)

Kabina, L.P.; Kondurov, I.A.; Shesterneva, I.M.

1983-12-01

Data needed for planning neutron activation analysis experiments and processing their results are given. The decay schemes of radioactive nuclei formed in irradiation with thermal neutrons during the (n,γ) reaction taken from the international ENSDF file are used for calculating the activities of nuclei and for drawing up an optimum table for identifying gamma lines in the spectra measured. (author)

Reactor neutron activation for multielemental analysis

International Nuclear Information System (INIS)

Reddy, A.V.R.

1999-01-01

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

Fissile materials in solution concentration measured by active neutron interrogation

International Nuclear Information System (INIS)

Romeyer Dherbey, J.; Passard, Ch.; Cloue, J.; Bignan, G.

1993-01-01

The use of the active neutron interrogation to measure the concentration of plutonium contained in flow solutions is particularly interesting for fuel reprocessing plants. Indeed, this method gives a signal which is in a direct relation with the fissile materials concentration. Moreover, it is less sensitive to the gamma dose rate than the other nondestructive methods. Two measure methods have been evolved in CEA. Their principles are given into details in this work. The first one consists to detect fission delayed neutrons induced by a 252 Cf source. In the second one fission prompt neutrons induced by a neutron generator of 14 MeV are detected. (O.M.)

Neutron activation and mass spectrometric measurement of /sup 129/I

International Nuclear Information System (INIS)

Strebin, R.S. Jr.; Brauer, F.P.; Kaye, J.H.; Rapids, M.S.; Stoffels, J.J.

1987-11-01

An integrated procedure has been developed for measurement of /sup 129/I by neutron activation analysis and mass spectrometry. An iodine isolation procedure previously used for neutron activation has been modified to provide separated iodine suitable for mass spectrometric measurement as well. Agreement between both methods has been achieved within error limits. The measurement limit by each method is about 10/sup 7/ atoms (2 fg) of /sup 129/I. 13 refs,. 4 figs., 1 tab

Calibration of activation detectors in a monoenergetic neutron beam. Contribution to criticality dosimetry

International Nuclear Information System (INIS)

Massoutie, Martine.

1981-05-01

Activation detectors have been calibrated for critical dosimetry applications. Measurements are made using a monoenergetic neutron flux. 14 MeV neutrons obtained par (D-T) reaction are produced by 150 kV accelerator. Neutron flux determined by different methods leads us to obtain an accuracy better than 6%. The present dosimetric system (Activation Neutron Spectrometer - SNAC) gives few informations in the (10 keV - 2 MeV) energetic range. The system has been improved and modified so that SNAC detectors must be read out by gamma spectrometer [fr

Elemental Study in Soybean and Products by Neutron Activation Analysis

International Nuclear Information System (INIS)

Vorapot, Permnamtip; Arporn Busamongkol; Sirinart, Laoharojanaphand

2009-07-01

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

Comparison of instrumental neutron activation analysis and instrumental charged-particle activation analysis for determining of Zn-68 abundance

International Nuclear Information System (INIS)

Rafii, H.; Mirzaei, M.; Aslani, G.R.; Kamali-Dehghan, M.; Rajamand, A-A.; Rahiminejad, A.; Mirzajani, N.; Sardari, D.; Shahabi, I.; Majidi, F.

2004-01-01

Gallium-67 has found important applications in nuclear medicine since last decades. The bombardment of enriched zinc-68 by proton beams in cyclotron is the most suitable method for the carrier-free production of this radionuclide. Any traces and isotopic impurities of the target cause serious radiological hazards because of their associated induced radioactivities. Trace analysis and Zn-68 content determination of the target material before any bombardment and chemical separation provide a valuable assessment of desired product. The elemental abundance evaluation of enriched isotopes is generally carried out by inductively coupled plasma-mass spectrometry method, ICP-Ms Instrumental neutron activation analysis and instrumental charged particle activation analysis. International neutron activation analysis and instrumental charged- particle activation analysis, looks be an alternative nuclear method for determining the abundance evaluation of enriched Zn-68 enrichment in two different samples has been studied by mean of international neutron activation analysis and instrumental charged- particle activation analysis . One sample was purchased from a French company, cortecnet, and the other was separated by an electromagnetic system in the Ions source department of our center, NRCAM. The neutron or proton irradiation was took place respectively in miniature neutron source reactor of Esfahan by flux of (1 to 5) 10 11 n/cm 2 .sec for 30 min and in Cyclon30 by 19 MeV proton beams of 100μA current for 12 min. The produced radioactivity was measured by HpGe detector for determination of trace impurities and evaluation of Zn-68 content in the samples. The result shows a good agreement with the reported ones by their producers and their low derivation of about ± indicates that the international neutron activation analysis and instrumental charged- particle activation analysis are relatively precise and rapid and each one can be used as a supplemental method for analyzing

DETERMINATION OF LIMIT DETECTION OF THE ELEMENTS N, P, K, Si, Al, Fe, Cu, Cd, WITH FAST NEUTRON ACTIVATION USING NEUTRON GENERATOR

Directory of Open Access Journals (Sweden)

Sunardi Sunardi

2010-06-01

Full Text Available Determination of limit detection of the elements N, P, K, Si, Al, Fe, Cu, Cd, with fast neutron activation using neutron generator has been done.  Samples prepared from SRM 2704, N, P, K elements from MERCK, Cu, Cd, Al from activation foil made in San Carlos, weighted and packed for certain weight then iradiated during 30 minutes with 14 MeV fast neutron using the neutron generator and then counted with gamma spectrometry (accuspec.  At this research condition of neutron generator was set at current 1 mA that produced neutron flux about 5,47.107 n/cm2.s and  experimental result shown that the limit detection for the elements N, P, K, Si, Al, Fe, Cu, Cd are  2,44 ppm, 1,88 ppm, 2,15 ppm, 1,44 ppm, 1,26 ppm, 1,35 ppm, 1,05 ppm, 2,99 ppm, respectively.  The data  indicate that the limit detection or sensitivity of appliance of neutron generator to analyze the element is very good, which is feasible to get accreditation AANC laboratory using neutron generator.   Keywords: limit detection, AANC, neutron generator

Instrumental neutron activation analysis - a routine method

International Nuclear Information System (INIS)

Bruin, M. de.

1983-01-01

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

Applications of neutron activation analysis in environmental science, biology and geoscience

International Nuclear Information System (INIS)

1992-01-01

The applications of neutron activation analysis technique with high sensitivity, good accuracy, multielemental analysis and non-destruction of samples in hydrosphere, soil and lithosphere, atmosphere, cosmosphere and biosphere were introduced in this book. A large amount of research activities in this field during the 20 years and more carried out by Neutron Activation Analysis Laboratory, Institute of High Energy Physics, Academia Sinica, was summarized. A number of the data and information with important scientific significance was provided

Reference neutron activation library

International Nuclear Information System (INIS)

2002-04-01

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

Reference neutron activation library

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-04-01

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

Determination of gold in some Myanmar indigenous medicines by neutron activation analysis

International Nuclear Information System (INIS)

Myint U.; Sein Sein Yi

1995-01-01

Gold has been determined in two Myanmar indigenous medicines TMF 14 (Devaauthada), TMF 15 (Shwe Thwe Say) by neutron activation analysis using an Am(Be) radionuclide neutron source. The activity of 411 keV of the 198 Au has been measured. (author). 2 refs., 1 fig., 1 tab

The verification of neutron activation analysis support system (cooperative research)

Energy Technology Data Exchange (ETDEWEB)

Sasajima, Fumio; Ichimura, Shigeju; Ohtomo, Akitoshi; Takayanagi, Masaji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Sawahata, Hiroyuki; Ito, Yasuo [Tokyo Univ. (Japan). Research Center for Nuclear Science and Technology; Onizawa, Kouji [Radiation Application Development Association, Tokai, Ibaraki (Japan)

2000-12-01

Neutron activation analysis support system is the system in which even the user who has not much experience in the neutron activation analysis can conveniently and accurately carry out the multi-element analysis of the sample. In this verification test, subjects such functions, usability, precision and accuracy of the analysis and etc. of the neutron activation analysis support system were confirmed. As a method of the verification test, it was carried out using irradiation device, measuring device, automatic sample changer and analyzer equipped in the JRR-3M PN-3 facility, and analysis software KAYZERO/SOLCOI based on the k{sub 0} method. With these equipments, calibration of the germanium detector, measurement of the parameter of the irradiation field and analysis of three kinds of environmental standard sample were carried out. The k{sub 0} method adopted in this system is primarily utilized in Europe recently, and it is the analysis method, which can conveniently and accurately carried out the multi-element analysis of the sample without requiring individual comparison standard sample. By this system, total 28 elements were determined quantitatively, and 16 elements with the value guaranteed as analytical data of the NIST (National Institute of Standards and Technology) environment standard sample were analyzed in the accuracy within 15%. This report describes content and verification result of neutron activation support system. (author)

Nitrogen determination in wheat by neutron activation analysis using fast neutron flux from a thermal nuclear reactor

International Nuclear Information System (INIS)

Ramirez G, T.

1976-01-01

This is a study of the technique for the determination of nitrogen and other elements in wheat flour through activation analysis with fast neutrons from a thermal nuclear reactor. The study begins with an introduction about the basis of the analytical methods, the equipment used in activation analysis and a brief description of the neutrons source. In the study are included the experiments carried out in order to determine the flux form in the site of irradiation, the N-13 half life and the interference due to the sample composition. (author)

Neutron activation analysis of Etruscan pottery

International Nuclear Information System (INIS)

Whitehead, J.; Silverman, A.; Ouellet, C.G.; Clark, D.D.; Hossain, T.Z.

1992-01-01

Neutron activation analysis (NAA) has been widely used in archaeology for compositional analysis of pottery samples taken from sites of archaeological importance. Elemental profiles can determine the place of manufacture. At Cornell, samples from an Etruscan site near Siena, Italy, are being studied. The goal of this study is to compile a trace element concentration profile for a large number of samples. These profiles will be matched with an existing data bank in an attempt to understand the place of origin for these samples. The 500 kW TRIGA reactor at the Ward Laboratory is used to collect NAA data for these samples. Experiments were done to set a procedure for the neutron activation analysis with respect to sample preparation, selection of irradiation container, definition of activation and counting parameters and data reduction. Currently, we are able to analyze some 27 elements in samples of mass 500 mg with a single irradiation of 4 hours and two sequences of counting. Our sensitivity for many of the trace elements is better than 1 ppm by weight under the conditions chosen. In this talk, details of our procedure, including quality assurance as measured by NIST standard reference materials, will be discussed. In addition, preliminary results from data treatment using cluster analysis will be presented. (author)

Calculation of thermal neutron self-shielding correction factors for aqueous bulk sample prompt gamma neutron activation analysis using the MCNP code

International Nuclear Information System (INIS)

Nasrabadi, M.N.; Jalali, M.; Mohammadi, A.

2007-01-01

In this work thermal neutron self-shielding in aqueous bulk samples containing neutron absorbing materials is studied using bulk sample prompt gamma neutron activation analysis (BSPGNAA) with the MCNP code. The code was used to perform three dimensional simulations of a neutron source, neutron detector and sample of various material compositions. The MCNP model was validated against experimental measurements of the neutron flux performed using a BF 3 detector. Simulations were performed to predict thermal neutron self-shielding in aqueous bulk samples containing neutron absorbing solutes. In practice, the MCNP calculations are combined with experimental measurements of the relative thermal neutron flux over the sample's surface, with respect to a reference water sample, to derive the thermal neutron self-shielding within the sample. The proposed methodology can be used for the determination of the elemental concentration of unknown aqueous samples by BSPGNAA where knowledge of the average thermal neutron flux within the sample volume is required

Ten year's activity in the field of neutron scattering workshop

International Nuclear Information System (INIS)

Hamaguchi, Yoshikazu

2003-01-01

'Neutron scattering' is in the frame of the 'Utilization of Research Reactor's of the FNCA (Forum for Nuclear Cooperation in Asia) project, which held the workshops from FY 1992. This report is a summary of the results and activities of neutron scattering workshops and sub-workshops since the start in FY 1992. (author)

Active neutron multiplicity analysis and Monte Carlo calculations

International Nuclear Information System (INIS)

Krick, M.S.; Ensslin, N.; Langner, D.G.; Miller, M.C.; Siebelist, R.; Stewart, J.E.; Ceo, R.N.; May, P.K.; Collins, L.L. Jr

1994-01-01

Active neutron multiplicity measurements of high-enrichment uranium metal and oxide samples have been made at Los Alamos and Y-12. The data from the measurements of standards at Los Alamos were analyzed to obtain values for neutron multiplication and source-sample coupling. These results are compared to equivalent results obtained from Monte Carlo calculations. An approximate relationship between coupling and multiplication is derived and used to correct doubles rates for multiplication and coupling. The utility of singles counting for uranium samples is also examined

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.

Neutron activation analysis of high purity tellurium

International Nuclear Information System (INIS)

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

1980-01-01

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

Applied research and development of neutron activation analysis

International Nuclear Information System (INIS)

Chung, Yong Sam; Moon, Jong Hwa; Kim, Sun Ha; Baek, Sung Ryel; Kim, Young Gi; Jung, Hwan Sung; Park, Kwang Won; Kang, Sang Hun; Lim, Jong Myoung

2003-05-01

The aims of this project are to establish the quality control system of Neutron Activation Analysis(NAA) due to increase of industrial needs for standard analytical method and to prepare and identify the standard operation procedure of NAA through practical testing for different analytical items. R and D implementations of analytical quality system using neutron irradiation facility and gamma-ray measurement system and automation of NAA facility in HANARO research reactor are as following ; 1) Establishment of NAA quality control system for the maintenance of best measurement capability and the promotion of utilization of HANARO research reactor 2) Improvement of analytical sensitivity for industrial applied technologies and establishment of certified standard procedures 3) Standardization and development of Prompt Gamma-ray Activation Analysis (PGAA) technology

Research and development activities of a neutron generator facility

International Nuclear Information System (INIS)

Darsono Sudjatmoko; Pramudita Anggraita; Sukarman Aminjoyo

2000-01-01

The neutron generator facility at YNRC is used for elemental analysis, nuclear data measurement and education. In nuclear data measurement the focus is on re-evaluating the existing scattered nuclear activation cross-section to obtain systematic data for nuclear reactions such as (n,p), (n,α), and (n,2n). In elemental analysis it is used for analyzing the Nitrogen (N), Phosphor (P) and Potassium (K) contents in chemical and natural fertilizers (compost), protein in rice, soybean, and corn and pollution level in rivers. The neutron generator is also used for education and training of BATAN staff and university students. The facility can also produce neutron generator components. (author)

Certification of standard reference materials employing neutron activation analysis

International Nuclear Information System (INIS)

Capote Rodriguez, G.; Hernandez Rivero, A.; Molina Insfran, J.; Ribeiro Guevara, S.; Santana Encinosa, C.; Perez Zayas, G.

1997-01-01

Neutron activation analysis (Naa) is used extensively as one of the analytical techniques in the certification of standard reference materials (Srm). Characteristics of Naa which make it valuable in this role are: accuracy; multielemental capability; ability to assess homogeneity; high sensitivity for many elements, and essentially non-destructive method. This paper reports the concentrations of thirty elements (major, minor and trace elements) in four Cuban Srm's. The samples were irradiated in a thermal neutron flux of 10 12 -10 13 neutrons.cm -2 .s -1 . The gamma-ray spectra were measured by HPGe detectors and were analysed using ACTAN program, developed in CEADEN. (author) [es

Methodology for iodine-129 determination in coniferous plant by neutron activation

International Nuclear Information System (INIS)

Quintana, E.E.; Thyssen, S.M.

1998-01-01

Full text: The measurement methods of iodine-129 ( 129 I) include liquid scintillation counting, mass spectrometry analysis, X-ray spectrometry and neutron activation analysis. The combination of long half-life and low radiation energy, limit the sensitivity of a direct measurement in environmental matrixes. The neutron activation analysis (NAA) permits the increase in the sensitivity because of the high thermal neutron cross section of 129 I. The reaction produced is 129 I (n,γ) 130 I and the Eγ (536 keV) of iodine-130 (t 1/2 = 12,6 hours) is measured. The developed methodology allows the determination of 129 I in coniferous needles using NAA. The chemical treatment removes the interferences present in the matrix, as well as the Bromine-82 originated in the activation process. The analytical method is divided in six steps: a) digestion by alkaline fusion; b) radiochemical purification of 129 I by distillation followed by solvent extraction; c) distillation and adsorption on activated charcoal; d) neutron irradiation; e) radiochemical purification of 130 I by distillation followed by solvent extraction; f) gamma spectrometry. Iodine-131 tracer is added, and a chemical recovery of 95% in the distillations is obtained. The whole process recovery is within 70% and 85%. The detection limit is 0.48 mBq. Several factors affect this value, such as sample type, variety of coniferous, natural iodine concentration, irradiation time and neutron flux. (author) [es

Neutron activation probe for measuring the presence of uranium in ore bodies

International Nuclear Information System (INIS)

Goldstein, N.P.; Smith, R.C.

1979-01-01

A neutron activation proble comprises a pulsed neutron source in series with a plurality of delayed neutron detectors for measuring radioactivity in a well borehole together with a NaI (Tl) counter for measuring the high energy 2.62 MeV gamma line from thorium. The neutron source emits neutrons which produce fission in uranium and thorium in the ore body and the delayed neutron detectors measure the delayed neutrons produced from such fission while the NaI (Tl) counter measures the 2.62 MeV gamma line from the undisturbed thorium in the ore body. The signal from the NaI (Tl) counter is processed and subtracted from the signal from the delayed neutron detectors with the result being indicative of the amount of uranium present in the ore body

Neutron activation analysis with k0-standardisation : general formalism and procedure

International Nuclear Information System (INIS)

Pomme, S.; Hardeman, F.; Robouch, P.; Etxebarria, N.; Arana, G.

1997-09-01

Instrumental neutron activation analysis (INAA) with k 0 -standardisation is a powerful tool for multi-element analysis at a broad range of trace element concentrations. An overview is given of the basic principles, fundamental equations, and general procedure of this method. Different aspects of the description of the neutron activation reaction rate are discussed, applying the Hogdahl convention. A general activation-decay formula is derived and its application to INAA is demonstrated. Relevant k 0 -definitions for different activation decay schemes are summarised and upgraded to cases of extremely high fluxes. The main standardisation techniques for INAA are discussed, emphasizing the k 0 -standardisation. Some general aspects of the basic equipment and its calibration are discussed, such as the characterisation of the neutron field and the tuning of the spectrometry part. A method for the prediction and optimisation of the analytical performance of INAA is presented

Radiolabeling of intact dosage forms by neutron activation: effects on in vitro performance

International Nuclear Information System (INIS)

Parr, A.; Jay, M.

1987-01-01

Compressed tablets containing various quantities of stable isotopes of Ba, Er, and Sm for use in neutron activation studies were evaluated for the effect of stable isotope incorporation on tablet hardness and disintegration times. At concentrations likely to be used in scintigraphic studies employing neutron activation as a radiolabeling method, no significant effect on in vitro parameters were observed. While the incorporation of stable isotopes influenced tablet hardness to a greater degree than disintegration time, irradiation of tablets in a neutron flux of 4.4 x 10(13) n/cm2 sec had a direct effect on tablet disintegration time. Thus, future neutron activation studies should focus on minimizing the amount of stable isotope to be incorporated with the formulation while using the shortest feasible irradiation time

Neutron dosimetry using activation of thermoluminescent CaSO 4

Science.gov (United States)

Azorín, Juan; Gutiérrez, Alicia

1984-11-01

Sulfur activation in calcium sulfate doped with dysprosium (CaSO 4:Dy) thermoluminescent powder, which is bound in pure sulfur, has been used to measure the fast neutron dose at the tangential beam port of a Triga Mark III reactor. After a post-irradiation time of 3 d, the dosimeters were annealed at 600°C for 30 min in order to erase all the thermoluminescence acquired during the irradiation. The dosimeters were then stored to allow self-irradiation by betas from 32P produced by sulfur activation. The thermoluminescent signal accumulated during a post-irradiation time of 20 d due to a neutron fluence of 2.2 × 10 11 n/cm 2 was equivalent to an absorbed dose of 10 mGy of 60Co gamma rays. The thermoluminescence as a function of fast neutron dose fitted to a straight line on a log-log scale from 1 Gy to 10 4Gy.

Triton burnup measurements in KSTAR using a neutron activation system

Energy Technology Data Exchange (ETDEWEB)

Jo, Jungmin; Shi, Yue-Jiang; Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.k; Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Cheon, MunSeong; Rhee, T.; Kim, Junghee [National Fusion Research Institute, Daejeon 34133 (Korea, Republic of); Kim, Jun Young [Korea University of Science and Technology, Daejeon 34133 (Korea, Republic of); Isobe, M.; Ogawa, K. [National Institute for Fusion Science, Toki-shi (Japan); SOKENDAI (The Graduate University for Advanced Studies), Toki-shi (Japan)

2016-11-15

Measurements of the time-integrated triton burnup for deuterium plasma in Korea Superconducting Tokamak Advanced Research (KSTAR) have been performed following the simultaneous detection of the d-d and d-t neutrons. The d-d neutrons were measured using a {sup 3}He proportional counter, fission chamber, and activated indium sample, whereas the d-t neutrons were detected using activated silicon and copper samples. The triton burnup ratio from KSTAR discharges is found to be in the range 0.01%–0.50% depending on the plasma conditions. The measured burnup ratio is compared with the prompt loss fraction of tritons calculated with the Lorentz orbit code and the classical slowing-down time. The burnup ratio is found to increase as plasma current and classical slowing-down time increase.

Neutron spectrum determination by activation method in fast neutron fields at the RB reactor

International Nuclear Information System (INIS)

Sokcic-Kostic, M.; Pesic, M.; Antic, D.

1994-01-01

The fast neutron fields of the RB reactor are presented in this paper. The activation method for spectrum determination is described and explained. The obtained results for intermediate and fast spectrum are given and discussed. (author)

Studies on thermal neutron perturbation factor needed for bulk sample activation analysis

CERN Document Server

Csikai, J; Sanami, T; Michikawa, T

2002-01-01

The spatial distribution of thermal neutrons produced by an Am-Be source in a graphite pile was measured via the activation foil method. The results obtained agree well with calculated data using the MCNP-4B code. A previous method used for the determination of the average neutron flux within thin absorbing samples has been improved and extended for a graphite moderator. A procedure developed for the determination of the flux perturbation factor renders the thermal neutron activation analysis of bulky samples of unknown composition possible both in hydrogenous and graphite moderators.

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

International Nuclear Information System (INIS)

Alian, A.; Sansoni, B.

1980-04-01

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

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

International Nuclear Information System (INIS)

Zhao Yunlong; Zhou Suqing; Liang Yutang

1988-05-01

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

Determination of manganese in some pyrolusite ores of Myanmar by neutron activation analysis

International Nuclear Information System (INIS)

Myint, U.; Swe, M.T.

1994-01-01

Manganese in pyrolusite ores from various regions of Myanmar was determined by thermal neutron activation analysis using an Am(Be) neutron source. The induced activities of 56 Mn were monitored by a γ-counting technique. (author) 2 refs.; 1 tab

Determination of manganese in some pyrolusite ores of Myanmar by neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Myint, U; Swe, M T [Yangon Univ. (Myanmar). Dept. of Chemistry

1994-05-17

Manganese in pyrolusite ores from various regions of Myanmar was determined by thermal neutron activation analysis using an Am(Be) neutron source. The induced activities of [sup 56]Mn were monitored by a [gamma]-counting technique. (author) 2 refs.; 1 tab.

Interpretation of active neutron measurements by the heterogeneous theory

International Nuclear Information System (INIS)

Birkhoff, G.; Depraz, J.; Descieux, J.P.

1979-01-01

In this paper are presented results from a study on the application of the heterogeneous method for the interpretation of active neutron measurements. The considered apparatus consists out of a cylindrical lead pile, which is provided with two axial channels: a central channel incorporates an antimony beryllium photoneutron source and an excentric channel serves for the insertion of the sample to be assayed for fissionable materials contents. The mathematical model of this apparatus is the heterogeneous group diffusion theory. Sample and source channel are described by multigroup monopolar and dipolar sources and sinks. Monopolar sources take account of neutron production within energy group and in-scatter from upper groups. Monopolar sinks represent neutron removal by absorption within energy group and outscatter to lower groups. Dipol sources describe radial streaming of neutrons across the sample channel. Multigroup diffusion theory is applied throughout the lead pile. The strengths of the monopolar and dipolar sources and sinks are determined by linear extrapolation distances of azimuthal mean and first harmonic flux values at the channels' surface. In an experiment we may measure the neutrons leaking out of the lead pile and linear extrapolation distances at the channels' surface. Such informations are utilized for interpretation in terms of fission neutron source strengh and mean neutron flux values in the sample. In this paper we summarized the theoretical work in course

Prompt gamma cold neutron activation analysis applied to biological materials

International Nuclear Information System (INIS)

Rossbach, M.; Hiep, N.T.

1992-01-01

Cold neutrons at the external neutron guide laboratory (ELLA) of the KFA Juelich are used to demonstrate their profitable application for multielement characterization of biological materials. The set-up and experimental conditions of the Prompt Gamma Cold Neutron Activation Analysis (PGCNAA) device is described in detail. Results for C, H, N, S, K, B, and Cd using synthetic standards and the 'ratio' technique for calculation are reported for several reference materials and prove the method to be reliable and complementary with respect to the elements being determined by INAA. (orig.)

Neutron-neutron probe for uranium exploration

International Nuclear Information System (INIS)

Smith, R.C.

1979-01-01

A neutron activation probe for assaying the amount of fissionable isotopes in an ore body is described which comprises a casing which is movable through a borehole in the ore body, a neutron source and a number of delayed neutron detectors arranged colinearly in the casing below the neutron source for detecting delayed neutrons

Multielement neutron-activation analysis of plants and fertilizers

International Nuclear Information System (INIS)

Srapenyants, R.A.; Saveliev, I.B.

1977-01-01

The development of an automated technique for simultaneous multielement activation analysis of plants and fertilizers for the macronutrient elements N, P, K, Ca, Mg, Cl, and Si is presented. The developed universal NAA is based on the installation manufactured and supplied by Sames, France. The components of the automatic installation for neutron activation analysis are: neutron generator; a pneumatic transfer system; a scintillation crystal detector; a spectrometer rack including a basic multichannel analyser; a control panel for the neutron generator and pneumatic transfer system; a computer and teletype. On the basis of analytical procedures, algorithms and software, the first automatic (computer based) installation for multielement analyses of plants and fertilizers has been completed and is in routine use in the agrochemical and plant breeding research program in the Soviet Union. The proposed technique together with the full automatic real-time process of measurement and processing of data by computer, provides a throughput of 250-500 samples (1250-2500 elements determinations) per 8-hour shift, with the accuracy of +-3%; for N and +-5%; for P, K, Mg, Cl and +-15% for Ca. (T.G.)

The influence of neutron activated products in BIXS method for tungsten

International Nuclear Information System (INIS)

Yang, Yang; Peng, Taiping; Chen, Zhilin; Zhang, Zhe; Song, Honghu

2016-01-01

Highlights: • An approach is proposed to assess the influence of neutron activated products in BIXS method for tungsten based on Monte Carlo simulations. • Six principal radioactive neutron activated products (W-181, W-185, W-187, Ta-182, Re-186 and Re-188) with exhaustive decay data were included in the calculation to simulate the real condition. • W-187 strongly affects the tritium measurement shortly after DT experiments and about one month later W-181, W-185 and Ta-182 dominate the effects of neutron activated products. • The intensity of spectrum devoted by NAPs is as much as 10.6 times larger than by tritium in the same region of interest (ROI) directly after reactor shutdown, while it will reduce to 0.83% after 19 months. - Abstract: Tritium β-decay Induced X-ray Spectroscopy (BIXS) is a promising method to obtain tritium retention details both on surface and in bulk of plasma facing materials (PFMs) in magnetic fusion devices. Influence of neutron activated products (NAPs) is one of the primary problems in BIXS, since the energy of Compton scattering photons and characteristic X-rays is close to the range of tritium β-rays. In this paper, Monte Carlo simulation was introduced to evaluate effects of NAPs in BIXS measurements for tungsten. Three steps are included in simulation, neutron flux simulation to reckon the neutron flux in PFMs based on the simplified model of ITER, activated products calculation to compute the distribution of NAPs in PFMs and radiation spectra simulation to calculate the spectra of NAPs in PFMs sample. Six typical nuclides (including W-185, W-181 and Re-188, etc.) produced by neutron irradiation were considered in this study. Finally, influence of NAPs was estimated quantitatively with the assumption that 1% of DT fuel retained in PFMs uniformly. It is found that the intensity of spectrum devoted by NAPs is as much as 10.6 times larger than it by tritium in the same region of interest (ROI) directly after reactor shutdown

The influence of neutron activated products in BIXS method for tungsten

Energy Technology Data Exchange (ETDEWEB)

Yang, Yang; Peng, Taiping, E-mail: yangyanginpc@163.com; Chen, Zhilin; Zhang, Zhe; Song, Honghu

2016-12-15

Highlights: • An approach is proposed to assess the influence of neutron activated products in BIXS method for tungsten based on Monte Carlo simulations. • Six principal radioactive neutron activated products (W-181, W-185, W-187, Ta-182, Re-186 and Re-188) with exhaustive decay data were included in the calculation to simulate the real condition. • W-187 strongly affects the tritium measurement shortly after DT experiments and about one month later W-181, W-185 and Ta-182 dominate the effects of neutron activated products. • The intensity of spectrum devoted by NAPs is as much as 10.6 times larger than by tritium in the same region of interest (ROI) directly after reactor shutdown, while it will reduce to 0.83% after 19 months. - Abstract: Tritium β-decay Induced X-ray Spectroscopy (BIXS) is a promising method to obtain tritium retention details both on surface and in bulk of plasma facing materials (PFMs) in magnetic fusion devices. Influence of neutron activated products (NAPs) is one of the primary problems in BIXS, since the energy of Compton scattering photons and characteristic X-rays is close to the range of tritium β-rays. In this paper, Monte Carlo simulation was introduced to evaluate effects of NAPs in BIXS measurements for tungsten. Three steps are included in simulation, neutron flux simulation to reckon the neutron flux in PFMs based on the simplified model of ITER, activated products calculation to compute the distribution of NAPs in PFMs and radiation spectra simulation to calculate the spectra of NAPs in PFMs sample. Six typical nuclides (including W-185, W-181 and Re-188, etc.) produced by neutron irradiation were considered in this study. Finally, influence of NAPs was estimated quantitatively with the assumption that 1% of DT fuel retained in PFMs uniformly. It is found that the intensity of spectrum devoted by NAPs is as much as 10.6 times larger than it by tritium in the same region of interest (ROI) directly after reactor shutdown

On neutron activation analysis with γγ coincidence spectrometry

International Nuclear Information System (INIS)

Zeisler, Rolf; Danyal Turkoglu; Ibere Souza Ribeiro Junior; Shetty, M.G.

2017-01-01

A new γγ coincidence system has been set up at NIST. It is operated with a digital data finder supported by new software developed at NIST. The system is used to explore possible enhancements in instrumental neutron activation analysis (INAA) and study applicability to neutron capture prompt gamma activation analysis (PGAA). The performance of the system is tested with certified reference materials for efficiency calibration and quantitative performance. Comparisons of INAA results based on conventional gamma-ray spectrometry data with INAA results based on coincidence data obtained from the same samples show improvements in the counting uncertainties and demonstrates the quantitative accuracy of the new system. (author)

Determination of silver using cyclic epithermal neutron activation analysis

International Nuclear Information System (INIS)

Pun, T.H.; Landsberger, S.

2012-01-01

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

Developments in Pulsed Neutron Activation for Determination of Water Flow in Pipes

CERN Document Server

Mattsson, H

2003-01-01

In PNA (pulsed neutron activation) it is important that the measured data can be related to the total mass flow. In this thesis two fundamental problems of the measurement technique and data treatment have been investigated: transport/mixing and background radiation. The principle of PNA is to introduce a radioactive substance into a pipe by bombarding fluid in the pipe with neutron pulses. The fluid in the pipe is activated and subsequently transported and mixed with the flow. Gamma radiation emitted from the activity is measured with one or two detectors downstream from the activation point. The time-resolved signal from the detectors is used to calculate the average velocity of the water flow. Due to the short distance between the neutron generator and the pipe the activity in the pipe becomes highly inhomogeneous. The transport and mixing of the activity were simulated using colour which was injected into the flow. It was found that the inhomogeneous activity distribution must be taken into account if the...

CHARACTERIZATION OF A THIN SILICON SENSOR FOR ACTIVE NEUTRON PERSONAL DOSEMETERS.

Science.gov (United States)

Takada, M; Nunomiya, T; Nakamura, T; Matsumoto, T; Masuda, A

2016-09-01

A thin silicon sensor has been developed for active neutron personal dosemeters for use by aircrews and first responders. This thin silicon sensor is not affected by the funneling effect, which causes detection of cosmic protons and over-response to cosmic neutrons. There are several advantages to the thin silicon sensor: a decrease in sensitivity to gamma rays, an improvement of the energy detection limit for neutrons down to 0.8 MeV and an increase in the sensitivity to fast neutrons. Neutron response functions were experimentally obtained using 2.5 and 5 MeV monoenergy neutron beams and a (252)Cf neutron source. Simulation results using the Monte Carlo N-Particle transport code agree quite well with the experimental ones when an energy deposition region shaped like a circular truncated cone is used in place of a cylindrical region. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A Kinematically Beamed, Low Energy Pulsed Neutron Source for Active Interrogation

International Nuclear Information System (INIS)

Dietrich, D.; Hagmann, C.; Kerr, P.; Nakae, L.; Rowland, M.; Snyderman, N.; Stoeffl, W.; Hamm, R.

2004-01-01

We are developing a new active interrogation system based on a kinematically focused low energy neutron beam. The key idea is that one of the defining characteristics of SNM (Special Nuclear Materials) is the ability for low energy or thermal neutrons to induce fission. Thus by using low energy neutrons for the interrogation source we can accomplish three goals, (1) Energy discrimination allows us to measure the prompt fast fission neutrons produced while the interrogation beam is on; (2) Neutrons with an energy of approximately 60 to 100 keV do not fission 238U and Thorium, but penetrate bulk material nearly as far as high energy neutrons do and (3) below about 100keV neutrons lose their energy by kinematical collisions rather than via the nuclear (n,2n) or (n,n') processes thus further simplifying the prompt neutron induced background. 60 keV neutrons create a low radiation dose and readily thermal capture in normal materials, thus providing a clean spectroscopic signature of the intervening materials. The kinematically beamed source also eliminates the need for heavy backward and sideway neutron shielding. We have designed and built a very compact pulsed neutron source, based on an RFQ proton accelerator and a lithium target. We are developing fast neutron detectors that are nearly insensitive to the ever-present thermal neutron and neutron capture induced gamma ray background. The detection of only a few high energy fission neutrons in time correlation with the linac pulse will be a clear indication of the presence of SNM

The IAEA collaborating centre for neutron activation based methodologies of research reactors

International Nuclear Information System (INIS)

Bode, P.

2010-01-01

The Reactor Institute Delft of the Delft University of Technology houses the Netherlands' only academic nuclear research reactor, with associated instrumentation and laboratories, for scientific education and research with ionizing radiation. The Institute's swimming pool type research reactor reached first criticality in 1963 and is currently operated at 2MW thermal powers on a 100 h/week basis. The reactor is equipped with neutron mirror guides serving ultra modern neutron beam physics instruments and with a very bright positron facility. Fully automated gamma-ray spectrometry systems are used by the laboratory for neutron activation analysis, providing large scale services under an ISO/IEC 17025:2005 compliant management system, being (since 1993) the first accredited laboratory of its kind in the world. Already for several years, this laboratory is sustainable by rendering these services to both the public and the private sector. The prime user of the Institute's fac ilities is the scientific Research Department of Radiation, Radionuclide and Reactors of the Faculty of Applied Sciences, housed inside the building. All reactor facilities are also made available for use by or for services to, external clients (industry, government, private sector, other (international research institutes and universities). The Reactor Institute Delft was inaugurated in May 2009 as a new lAEA Collaborating Centre for Neutron Activation Based Methodologies of Research Reactors. The collaboration involves education, research and development in (I) Production of reactor-produced, no-carrier added radioisotopes of high specific activity via neutron activation; (II) Neutron activation analysis with emphasis on automation as well as analysis of large samples, and radiotracer techniques and as a cross-cutting activity, (IIl) Quality assurance and management in research and application of research reactor based techniques and in research reactor operations. This c ollaboration will

Fast neutron spectra determination by threshold activation detectors using neural networks

International Nuclear Information System (INIS)

Kardan, M.R.; Koohi-Fayegh, R.; Setayeshi, S.; Ghiassi-Nejad, M.

2004-01-01

Neural network method was used for fast neutron spectra unfolding in spectrometry by threshold activation detectors. The input layer of the neural networks consisted of 11 neurons for the specific activities of neutron-induced nuclear reaction products, while the output layers were fast neutron spectra which had been subdivided into 6, 8, 10, 12, 15 and 20 energy bins. Neural network training was performed by 437 fast neutron spectra and corresponding threshold activation detector readings. The trained neural network have been applied for unfolding 50 spectra, which were not in training sets and the results were compared with real spectra and unfolded spectra by SANDII. The best results belong to 10 energy bin spectra. The neural network was also trained by detector readings with 5% uncertainty and the response of the trained neural network to detector readings with 5%, 10%, 15%, 20%, 25% and 50% uncertainty was compared with real spectra. Neural network algorithm, in comparison with other unfolding methods, is very fast and needless to detector response matrix and any prior information about spectra and also the outputs have low sensitivity to uncertainty in the activity measurements. The results show that the neural network algorithm is useful when a fast response is required with reasonable accuracy

Activation product analysis in a mixed sample containing both fission and neutron activation products

Energy Technology Data Exchange (ETDEWEB)

Morrison, Samuel S.; Clark, Sue B.; Eggemeyer, Tere A.; Finn, Erin C.; Hines, C. Corey; King, Mathew D.; Metz, Lori A.; Morley, Shannon M.; Snow, Mathew S.; Wall, Donald E.; Seiner, Brienne N.

2017-11-02

Activation analysis of gold (Au) is used to estimate neutron fluence resulting from a criticality event; however, such analyses are complicated by simultaneous production of other gamma-emitting fission products. Confidence in neutron fluence estimates can be increased by quantifying additional activation products such as platinum (Pt), tantalum (Ta), and tungsten (W). This work describes a radiochemical separation procedure for the determination of these activation products. Anion exchange chromatography is used to separate anionic forms of these metals in a nitric acid matrix; thiourea is used to isolate the Au and Pt fraction, followed by removal of the Ta fraction using hydrogen peroxide. W, which is not retained on the first anion exchange column, is transposed to an HCl/HF matrix to enhance retention on a second anion exchange column and finally eluted using HNO3/HF. Chemical separations result in a reduction in the minimum detectable activity by a factor of 287, 207, 141, and 471 for 182Ta, 187W, 197Pt, and 198Au respectively, with greater than 90% recovery for all elements. These results represent the highest recoveries and lowest minimum detectable activities for 182Ta, 187W, 197Pt, and 198Au from mixed fission-activation product samples to date, enabling considerable refinement in the measurement uncertainties for neutron fluences in highly complex sample matrices.

Investigations on the comparator technique used in epithermal neutron activation analysis

International Nuclear Information System (INIS)

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

1977-01-01

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

Gamma-neutron activation experiments using laser wakefield accelerators

International Nuclear Information System (INIS)

Leemans, W.P.; Rodgers, D.; Catravas, P.E.; Geddes, C.G.R.; Fubiani, G.; Esarey, E.; Shadwick, B.A.; Donahue, R.; Smith, A.

2001-01-01

Gamma-neutron activation experiments have been performed with relativistic electron beams produced by a laser wakefield accelerator. The electron beams were produced by tightly focusing (spot diameter ≅6 μm) a high power (up to 10 TW), ultra-short (≥50 fs) laser beam from a high repetition rate (10 Hz) Ti:sapphire (0.8 μm) laser system, onto a high density (>10 19 cm -3 ) pulsed gasjet of length ≅1.5 mm. Nuclear activation measurements in lead and copper targets indicate the production of electrons with energy in excess of 25 MeV. This result was confirmed by electron distribution measurements using a bending magnet spectrometer. Measured γ-ray and neutron yields are also found to be in reasonable agreement with simulations using a Monte Carlo transport code

Fast neutron activation analysis using short-lived radionuclides

International Nuclear Information System (INIS)

Salma, I.; Zemplen-Papp, E.

1993-01-01

Fast neutron activation analysis experiments were performed to investigate the analytical possibilities and prospective utilization of short-lived activation products. A rapid pneumatic transfer system for use with neutron generators has been installed and applied for detecting radionuclides with a half-life from ∼300 ms to 20 s. The transport time for samples of total mass of 1-4 g is between 130 and 160 ms for pressurized air of 0.1-0.4 MPa. The reproducibility of transport times is less than 2%. The employed method of correcting time-dependent counting losses is based on the virtual pulse generator principle. The measuring equipment consists of CAMAC modules and a special gating circuit. Typical time distributions of counting losses are presented. The same 14 elements were studied by the conventional activation method (single irradiation and single counting) by both a typical pneumatic transport system (run time 3 s) and the fast pneumatic transport facility. Furthermore, the influence of the cyclic activation technique on the elemental sensitivities was investigated. (author) 15 refs.; 5 figs.; 3 tabs

Neutron activation analysis of artefacts

International Nuclear Information System (INIS)

Mohd Suhaimi Hamzah; Shamsiah Abd Rahman

2004-01-01

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

Estimation of 129I by low energy spectrometry and neutron activation analysis

International Nuclear Information System (INIS)

Ravi, P.M.; Iyer, M.R.; Sahasrabudhe, S.G.; Somasundaram, S.; Subramanian, M.S.

1986-01-01

Methods have been developed for the estimation of 129 I by direct passive counting and by neutron activation analysis. The direct counting method using low energy photon spectrometry has been standardised for liquid samples. Interference from different induced radionuclides in the activation method was studied. Limits of detection of 129 I by direct counting method and neutron activation analysis work out to be 0.4 Bq and 1mBq respectively. (author). 6 refs

Neutron spectrum determination by activation method in fast neutron fields at the RB reactors

International Nuclear Information System (INIS)

Sokcic-Kostic, M.S.; Pesic, M.P.; Antic, D.P.

1994-01-01

The fast neutron fields of the RB reactor are presented in this paper. The activation method for spectrum determination is described and explained. The obtained results for intermediate and fast spectrum are given and discussed. (authors). 7 refs., 3 tabs

Multi-element analysis of crude-oil samples by 14.6 MeV neutron activation

International Nuclear Information System (INIS)

Cam, N.F.; Cigeroglu, F.; Erduran, M.N.

1997-01-01

The instrumental neutron activation technique, using the SAMEST T-400 neutron generator with 14.6 MeV neutrons produced from 3 H(d,n) 4 He reaction, is demonstrated for multi-element analysis of Saudi-Arabian crude-oil samples. The system parameters for the absolute method (e.g., the counting solid-angle, intrinsic efficiency of the γ-ray detector, effective neutron flux, activation cross sections, etc.)were determined and the results of elemental concentrations were presented with the corrections for all possible interferences having been carefully considered. (author)

Feasibility of calibration of liquid sodium flowmeters by neutron activation techniques

International Nuclear Information System (INIS)

Kehler, P.

1976-07-01

Velocities of fluids in pipes can be measured by injecting radioactive tracers into the fluid and recording the activity downstream of the injection point. One convenient method of injecting radioactive tracers is by neutron activation of the fluid itself. The present report describes a FORTRAN program that can be used for the prediction of the counting rates of fluid flow tests performed with a pulsed neutron source and a scintillation detector. The program models the flow profile and the mixing of the fluid, the attenuation of neutrons and gamma rays in the fluid, and the geometric arrangement of the source and the detector. Using this program, an experiment for the measurement of the secondary sodium flow of the EBR-II was optimized. A pulsed D,T neutron source and a 5 in. x 5 in. NaI detector will be used in the EBR-II test. Under optimized conditions, the expected accuracy of the flow measurement is about 2 percent

Elemental analysis of combustion products by neutron activation

International Nuclear Information System (INIS)

Heft, R.E.; Koszykowski, R.F.

1980-01-01

This paper gives a brief description of the neutron activation analysis method, which is being used to determine the elemental profile of combustion products from coal-fired power plants, oil shale retorting, and underground coal gasification

Neutron activation in EBT-P

International Nuclear Information System (INIS)

Driemeyer, D.E.

1983-01-01

Neutron activation due to photoneutron production in the lead shields proposed to protect the EBT-P superconducting coils from excessive x-ray heating was investigated. The photoneutron flux distribution in various EBT-P structural components was calculated for typical upgrade operating conditions using a standard two-dimensional transport model (TWOTRAN). Activity levels were then evaluated for major structural materials using activation cross sections tabulated in the GAMMON library. Activation dose rates in the device enclosure following several days of 8h/day upgrade (90GHz) operation were found to be approx. 6 mrem/h, decaying to <0.25 mrem/h in approx. 3 days. This requires radiation monitoring of all personnel entering the device enclosure during this time, but should not generally restrict hands on access to the device. There is thus no strong motivation to replace lead with another shield material; however, it may be desirable to borate the enclosure walls in order to reduce the effect which impurities might have on activity levels

SHREDI, Neutron Flux and Neutron Activation in 2-D Shields by Removal Diffusion

International Nuclear Information System (INIS)

Daneri, A.; Toselli, G.

1976-01-01

1 - Nature of physical problem solved: SHREDI is a removal - diffusion neutron shielding code. The program computes neutron fluxes and activations in bidimensional sections (x,y or r,z) of the shield. It is also possible to consider shielding points with the same y or z coordinate (mono-dimensional problems). 2 - Method of solution: The integrals which define the removal fluxes are computed in some shield points by means of a particular algorithm based on the Simpson's and trapezoidal rules. For the diffusion calculation the finite difference method is used. The removal sources are interpolated in all diffusion points by Chebyshev polynomials. 3 - Restrictions on the complexity of the problem: Maxima: number of removal energy groups NGR = 40; number of diffusion energy groups NGD = 40; number of the reactor core and shield materials NCMP = 50; number of core mesh points in r (or x) direction for integral calculation = 75; number of core mesh points in z (or y) direction for integral calculation = 75; number of core mesh points in theta (or z) direction for integral calculation = 75; number of shield mesh points for the neutron flux calculation in r (or x) direction NPX = 200; number of shield mesh points for the neutron flux calculation in z (or y) direction NPY = 200; n.b. (NPX * NPY) le 12000

Non-traditional neutron activation analysis by use of a nuclear reactor

International Nuclear Information System (INIS)

Mukhammedov, S.

2003-01-01

Full text: Traditional reactor neutron activation analysis (NAA) based on (n, γ) - thermal neutron capture nuclear reaction has been developed into a reliable and powerful analytical method, for trace element analysis, allowing the determination of over 60 chemical elements, with good accuracy and low detection limits. Considering all possibilities of activation and a radiochemical separation of the indicator radionuclide, the majority of the elements of this group can be determined at the ppm concentration level and below. However, for solving a number of analytical problems NAA technique is not well suited or it cannot be used at all. An important limitation is that all light elements, some medium and heavy elements cannot be determined even at ppm concentration level by this method, for example, H, Be, Li, B, C, N, O, Ti, Nb, Pb, etc. Accurate determination of lithium, oxygen and other light elements in sub-microgram level is of importance in geochemical and material studies. Such examples are great many. On such instances, several non-traditional reactor activation analysis can be used which have increasingly been developed and applied to several fields of semiconductor industry, biology, geology in recent years. The purpose of this presentation is to review the modern status of non-traditional nuclear reactor activation analysis based on use of nuclear reactions excited by the flow of secondary charged particles which are produced by two methods. In first method the triton flow is produced by thermal neutrons flux which excites the nuclear reaction 6 Li(n, α)T on lithium. The neutron activation analysis associated with two consecutive reactions 6 Li(n, α)T + 16 O(T, n) 18 F is established to determine trace amounts either of lithium or of oxygen in different geological, ecological and technological samples. Besides, the triton flow can be used for the determination of other light elements, for instance, B, N, S, Mg. This nuclear reactor triton activation

Prompt-gamma neutron activation analysis system design. Effects of D-T versus D-D neutron generator source selection

International Nuclear Information System (INIS)

Shypailo, R.J.; Ellis, K.J.

2008-01-01

Prompt-gamma neutron activation (PGNA) analysis is used for the non-invasive measurement of human body composition. Advancements in portable, compact neutron generator design have made those devices attractive as neutron sources. Two distinct generators are available: D-D with 2.5 MeV and D-T with 14.2 MeV neutrons. To compare the performance of these two units in our present PGNA system, we performed Monte Carlo simulations (MCNP-5; Los Alamos National Laboratory) evaluating the nitrogen reactions produced in tissue-equivalent phantoms and the effects of background interference on the gamma-detectors. Monte Carlo response curves showed increased gamma production per unit dose when using the D-D generator, suggesting that it is the more suitable choice for smaller sized subjects. The increased penetration by higher energy neutrons produced by the D-T generator supports its utility when examining larger, especially obese, subjects. A clinical PGNA analysis design incorporating both neutron generator options may be the best choice for a system required to measure a wide range of subject phenotypes. (author)

Aspects of precision and accuracy in neutron activation analysis

International Nuclear Information System (INIS)

Heydorn, K.

1980-03-01

Analytical results without systematic errors and with accurately known random errors are normally distributed around their true values. Such results may be produced by means of neutron activation analysis both with and without radiochemical separation. When all sources of random variation are known a priori, their effect may be combined with the Poisson statistics characteristic of the counting process, and the standard deviation of a single analytical result may be estimated. The various steps of a complete neutron activation analytical procedure are therefore studied in detail with respect to determining their contribution to the overall variability of the final result. Verification of the estimated standard deviation is carried out by demonstrating the absence of significant unknown random errors through analysing, in replicate, samples covering the range of concentrations and matrices anticipated in actual use. Agreement between the estimated and the observed variability of replicate results is then tested by a simple statistic T based on the chi-square distribution. It is found that results from neutron activation analysis on biological samples can be brought into statistical control. In routine application of methods in statistical control the same statistical test may be used for quality control when some of the actual samples are analysed in duplicate. This analysis of precision serves to detect unknown or unexpected sources of variation of the analytical results, and both random and systematic errors have been discovered in practical trace element investigations in different areas of research. Particularly, at the ultratrace level of concentration where there are few or no standard reference materials for ascertaining the accuracy of results, the proposed quality control based on the analysis of precision combined with neutron activation analysis with radiochemical separation, with an a priori precision independent of the level of concentration, becomes a

Simulation and preliminary experimental results for an active neutron counter using a neutron generator for a fissile material accounting

International Nuclear Information System (INIS)

Ahn, Seong-Kyu; Lee, Tae-Hoon; Shin, Hee-Sung; Kim, Ho-Dong

2009-01-01

An active neutron coincidence counter using a neutron generator as an interrogation source has been suggested. Because of the high energy of the interrogation neutron source, 2.5 MeV, the induced fission rate is strongly affected by the moderator design. MCNPX simulation has been performed to evaluate the performance achieved with these moderators. The side- and bottom-moderator are significantly important to thermalize neutrons to induce fission. Based on the simulation results, the moderators are designed to be adapted to the experimental system. Their preliminary performance has been tested by using natural uranium oxide powder samples. For a sample of up to 3.5 kg, which contains 21.7 g of 235 U, 2.64 cps/g- 235 U coincidence events have been measured. Mean background error was 9.57 cps and the resultant coincidence error was 13.8 cps. The experimental result shows the current status of an active counting using a neutron generator which still has some challenges to overcome. However, the controllability of an interrogation source makes this system more applicable for a variety of combinations with other non-destructive methods like a passive coincidence counting especially under a harsh environment such as a hot cell. More precise experimental setup and tests with higher enriched samples will be followed to develop a system to apply it to an active measurement for the safeguards of a spent fuel treatment process.

Defensive and pathological functions of the gastrointestinal NK3 receptor.

Science.gov (United States)

Sanger, Gareth J; Tuladhar, Bishwa R; Bueno, Lionel; Furness, John B

2006-10-01

In general, normal gut functions are unaffected by selective NK(3) receptor antagonists such as talnetant (SB-223412), osanetant (SR 142901) or SB-235375. However, NK(3) receptors may mediate certain defensive or pathological intestinal processes. The precise mechanisms, by which this role is achieved, are not fully understood. In summary, intense stimulation of the intrinsic primary afferent neurones (IPANs) of the enteric nervous system is thought to release tachykinins from these neurones, to induce slow excitation (slow EPSPs) of connecting IPANs. This is hypothesised to cause hypersensitivity and disrupt intestinal motility, at least partly explaining why NK(3) receptor antagonism can reduce the level of disruption caused by supramaximal distension pressures in vitro. Tachykinin release from IPANs may also increase C-fibre sensitivity, directly or indirectly. Thus, NK(3) receptor antagonists can inhibit nociception associated with intestinal distension, in normal animals or after pre-sensitisation by restraint stress. Importantly, such inhibition has been found with SB-235375, a peripherally restricted antagonist. SB-235375 can also reduce a visceromotor response to brief colorectal distension without affecting similar responses to skin pinch, providing additional evidence for intestinal-specific activity. NK(3) receptor biology is, therefore, revealing a novel pathway by which disruptions in intestinal motility and nociception can be induced.

Comparison of Americium-Beryllium neutron spectrum obtained using activation foil detectors and NE-213 spectrometer

International Nuclear Information System (INIS)

Sunny, Sunil; Subbaiah, K.V.; Selvakumaran, T.S.

1999-01-01

Neutron spectrum of Americium - Beryllium (α,n) source is measured with two different spectrometers vis-a-vis activation foils (foil detectors) and NE-213 organic scintillator. Activity induced in the foils is measured with 4π-β-γ sodium iodide detector by integrating counts under photo peak and the saturation activity is found by correcting to elapsed time before counting. The data on calculated activity is fed into the unfolding code, SAND-II to obtain neutron spectrum. In the case of organic scintillator, the pulse height spectrum is obtained using MCA and this is processed with unfolding code DUST in order to get neutron spectrum. The Americium - Beryllium (α,n) neutron spectrum thus obtained by two different methods is compared. It is inferred that the NE-213 scintillator spectrum is in excellent agreement with the values beyond 1MeV. Neutron spectrum obtained by activation foils depends on initial guess spectrum and is found to be in reasonable agreement with NE-213 spectrum. (author)

Absolute instrumental neutron activation analysis at Lawrence Livermore Laboratory

International Nuclear Information System (INIS)

Heft, R.E.

1977-01-01

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

Microscopic cross-section measurements by thermal neutron activation

International Nuclear Information System (INIS)

Avila L, J.

1987-08-01

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

Factors affecting neutron measurements and calculations. Part C. Trace element concentrations in granite and their impact on thermal neutron activation

International Nuclear Information System (INIS)

Ruehm, Werner; Huber, Thomas; Nolte, Eckehart; Kato, Kazuo; Imanaka, Tetsuji; Egbert, Stephen D.

2005-01-01

Trace elements such as Li, B, Sm, and Gd can, despite their low elemental concentration in mineral materials, influence thermal neutron activation in Hiroshima and Nagasaki samples, due to their high thermal neutron absorption cross sections. This was demonstrated for a granite core, where the addition of those trace elements to the elemental composition of granite reduces the production of 152 Eu by some 25% at a depth of 25 cm from the surface. If typical concentrations of those trace elements are added to DS02 reference soil, however, the production of 152 Eu one meter above ground is not changed significantly, because of the high water content of the soil. This indicates that DS02 soil represents a reasonable reference material for the air-over-ground transport calculations. It must be kept in mind, however, that the local environment of any sample investigated for thermal neutron activation might be characterized by other elemental compositions. In particular, trace element and hydrogen concentrations could be considerably different from those used for DS02 reference soil. As an example it was demonstrated that in a granite gravestone thermal neutron activation of 36 Cl close to the surface might be, in the worst case, reduced by some 30%, due to increased local granite concentration in this type of environment. Beside other parameters such as, for example, individual sample geometry, the variability of trace elements in soil might be one reason for the variability that is observed in the individual thermal neutron activation measurements (Gold 1995). It is necessary, therefore, to carefully model the exposure geometry of the exposed material, its chemical composition, and the surrounding interface materials in order to obtain the best possible agreement in comparisons between calculated and measured data for thermal neutrons. (author)

Morphological evidence for novel enteric neuronal circuitry in guinea pig distal colon.

Science.gov (United States)

Smolilo, D J; Costa, M; Hibberd, T J; Wattchow, D A; Spencer, Nick J

2018-07-01

The gastrointestinal (GI) tract is unique compared to all other internal organs; it is the only organ with its own nervous system and its own population of intrinsic sensory neurons, known as intrinsic primary afferent neurons (IPANs). How these IPANs form neuronal circuits with other functional classes of neurons in the enteric nervous system (ENS) is incompletely understood. We used a combination of light microscopy, immunohistochemistry and confocal microscopy to examine the topographical distribution of specific classes of neurons in the myenteric plexus of guinea-pig colon, including putative IPANs, with other classes of enteric neurons. These findings were based on immunoreactivity to the neuronal markers, calbindin, calretinin and nitric oxide synthase. We then correlated the varicose outputs formed by putative IPANs with subclasses of excitatory interneurons and motor neurons. We revealed that calbindin-immunoreactive varicosities form specialized structures resembling 'baskets' within the majority of myenteric ganglia, which were arranged in clusters around calretinin-immunoreactive neurons. These calbindin baskets directly arose from projections of putative IPANs and represent morphological evidence of preferential input from sensory neurons directly to a select group of calretinin neurons. Our findings uncovered that these neurons are likely to be ascending excitatory interneurons and excitatory motor neurons. Our study reveals for the first time in the colon, a novel enteric neural circuit, whereby calbindin-immunoreactive putative sensory neurons form specialized varicose structures that likely direct synaptic outputs to excitatory interneurons and motor neurons. This circuit likely forms the basis of polarized neuronal pathways underlying motility. © 2018 Wiley Periodicals, Inc.

An investigation of tungsten by neutron activation techniques

International Nuclear Information System (INIS)

Svetsreni, R.

1978-01-01

This investigation used neutron from Plutonium-Beryllium source (5 curie) to analyse the amount of tungsten in tungsten oxide which was extracted from tungsten ores, slag and tungsten alloy of tungsten iron and carbon. The technique of neutron activation analysis with NaI(Tl) gamma detector 3'' x 3'' and 1024 multichannel analyzer. The dilution technique was used by mixing Fe 2 O 3 or pure sand into the sample before irradiation. In this study self shielding effect in the analysis of tungsten was solved and the detection limit of the tungsten in the sample was about 0.5%

EASY-2005.1, European Neutron Activation System

International Nuclear Information System (INIS)

Forrest, R.A.; Sublet, Jean-Christophe

2008-01-01

1 - Description of program or function: The EASY-2005 (European Activation System) consists of a wide range of codes, data and documentation all aimed at satisfying the objective of calculating the response of materials irradiated in a neutron flux. The main difference from the previous version is the upper energy limit which has increased from 20 to 60 MeV. It is designed to investigate both fusion devices and accelerator based materials test facilities that will act as intense sources of high energy neutrons causing significant activation of the surrounding materials. The very general nature of the calculational method and the data libraries means that it is applicable (with some reservations) to all situations (e.g. fission reactors or neutron sources) where materials are exposed to neutrons below 60 MeV. EASY can be divided into two parts: data and code development tools and user tools and data. The former are required to develop the latter, but EASY users only need to be able to use the inventory code FISPACT and be aware of the contents of the EAF library (the data source). The complete EASY package contains the FISPACT-2005 inventory code, the EAF-2005 library, and the EASY User Interface. The activation package EASY-2005 [1] is the result of significant development to extend the upper energy range from 20 to 60 MeV so that it is capable of being used for IFMIF calculations. The EAF-2005 library contains 62,637 reactions, almost five times more than in EAF-2003 (12,617). Such a large increase means that some mistakes may exist in the new file that need to be corrected. Because of these shortcomings and for other reasons explained below, a maintenance release, EAF-2005.1 has been produced. A deuteron-induced cross section library was also included for the first time, and can be used with EASY to enable calculations of the activation due to deuterons [2]. This library is included in the EASY-2005.1 maintenance release as is a new version of the FISPACT code

The determination of some impurities in zirconium metal by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Eddy, B.T.; Pearton, D.C.G.; Watterson, J.J.

1976-01-01

This report describes the work done on the development of an instrumental neutron-activation method for the analysis of impurities in reactor-grade zirconium. Nine samples were analysed, and the results were compared with those obtained by other techniques. No statistically significant differences were observed for ten of the twelve elements that could possibly be determined by instrumental neutron-activation analysis. Cadmium cannot be determined at the 0,5 p.p.m. level, and there is doubt about the comparative values recorded for aluminium. The precision of the measurement by direct instrumental neutron-activation analysis ranges from 1,4 per cent for tungsten to 17 per cent for chromium [af

Activation measurements for thermal neutrons. Part A. Cobalt (60Co) activation

International Nuclear Information System (INIS)

Kerr, George D.; Shizuma, Kiyoshi; Endo, Satoru; Maruyama, Takashi; Cullings, Harry M.; Komura, Kazuhisa; Okumura, Yutaka; Egbert, Stephen D.

2005-01-01

The 60 Co measurements at Hiroshima and Nagasaki were reviewed and compared with the results of the new DS02 calculations for the two cities. Some corrections were made to previously published data from the 1965 measurements of JNIRS, ground ranges of all of the 60 Co measurements were reviewed and new ground ranges were determined when possible by transforming sample coordinates to the new city maps for Hiroshima and Nagasaki, and transmission factors were investigated for a number of samples used in the 60 Co measurements. Transmission factors were not calculated for all samples used in the 60 Co measurements but some general rules were given for estimating transmission factors for these samples. Experimental measurements of the background 60 Co activity from environmental neutrons were also reviewed, and it was found that the 60 Co background from environmental neutrons was not an important factor in the 60 Co measurements of bomb-induced activity at either city. (J.P.N.)

Diagnosis of mucoviscidosis by neutron activation analysis. Part 1; Diagnostico da mucoviscidose utilizando analise por ativacao com neutrons. Parte 1

Energy Technology Data Exchange (ETDEWEB)

Bellido, Luis F.; Bellido, Alfredo V

1997-02-01

Symptoms pathology, incidence, and gravity of the inherent syndrome called mucoviscidosis, or cystic fibrosis are described in this Part I. The analytical methods used for its diagnosis, both the conventional chemical ones and by neutron activation analysis are also summarised. Finally, an analytical method to study the incidence of mucoviscidosis in Brazil is presented. This , essentially, consists in bromine determination, in fingernails, by resonance neutron activation analysis. (author) 33 refs., 13 figs.

Targets for the production of neutron activated molybdenum-99

International Nuclear Information System (INIS)

Hetherington, E.L.R.; Boyd, R.E.

1999-01-01

Neutron activation of natural molybdenum is, ostensibly, the least complex route to 99m Tc. However in most commercial generators the severe limitation in 99 Mo specific activity that the route imposes has caused manufacturers to choose the alternative fission process despite its disadvantages of being more expensive and requiring a more complex waste management strategy. The development of a newer generator technology is capable of reviving the demand for neutron activated 99 Mo and might encourage the production of 99m Tc by countries possessing less developed nuclear infrastructures. The targets used in the (n,γ) production route consist of analytical grade molybdenum trioxide which has been further refined to remove both rhenium and tungsten trace impurities. The basic methods used by ANSTO to produce a molybdenum target capable of yielding 99m Tc of high radionuclidic purity are described. (author)

Selected industrial and environmental applications of neutron activation analysis

International Nuclear Information System (INIS)

Kucera, J.

1999-01-01

A review of the applications of Instrumental Neutron Activation Analysis (INAA) in the industrial and environmental fields is given. Detection limits for different applications are also given. (author)

The cross-section data from neutron activation experiments on niobium in the NPI p-7Li quasi-monoenergetic neutron field

Directory of Open Access Journals (Sweden)

Simakov S.P.

2010-10-01

Full Text Available The reaction of protons on 7Li target produces the high-energy quasi- monoenergetic neutron spectrum with the tail to lower energies. Proton energies of 19.8, 25.1, 27.6, 30.1, 32.6, 35.0 and 37.4 MeV were used to obtain quasi-monoenergetic neutrons with energies of 18, 21.6, 24.8, 27.6, 30.3, 32.9 and 35.6 MeV, respectively. Nb cross-section data for neutron energies higher than 22.5 MeV do not exist in the literature. Nb is the important material for fusion applications (IFMIF as well. The variable-energy proton beam of NPI cyclotron is utilized for the production of neutron field using thin lithium target. The carbon backing serves as the beam stopper. The system permits to produce neutron flux density about 109  n/cm2/s in peak at 30 MeV neutron energy. The niobium foils of 15 mm in diameter and approx. 0.75 g weight were activated. The nuclear spectroscopy methods with HPGe detector technique were used to obtain the activities of produced isotopes. The large set of neutron energies used in the experiment allows us to make the complex study of the cross-section values. The reactions (n,2n, (n,3n, (n,4n, (n,He3, (n,α and (n,2nα are studied. The cross-sections data of the (n,4n and (n,2nα are obtained for the first time. The cross-sections of (n,2n and (n,α reactions for higher neutron energies are strongly influenced by low energy tail of neutron spectra. This effect is discussed. The results are compared with the EAF-2007 library.

Neutron activation analysis of high purity substances

International Nuclear Information System (INIS)

Gil'bert, Eh.N.

1987-01-01

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

Activation experiment for concrete blocks using thermal neutrons

Science.gov (United States)

Okuno, Koichi; Tanaka, Seiichiro

2017-09-01

Activation experiments for ordinary concrete, colemanite-peridotite concrete, B4C-loaded concrete, and limestone concrete are carried out using thermal neutrons. The results reveal that the effective dose for gamma rays from activated nuclides of colemanite-peridotite concrete is lower than that for the other types of concrete. Therefore, colemanite-peridotite concrete is useful for reducing radiation exposure for workers.

Validation of MCNP NPP Activation Simulations for Decommissioning Studies by Analysis of NPP Neutron Activation Foil Measurement Campaigns

Directory of Open Access Journals (Sweden)

Volmert Ben

2016-01-01

Full Text Available In this paper, an overview of the Swiss Nuclear Power Plant (NPP activation methodology is presented and the work towards its validation by in-situ NPP foil irradiation campaigns is outlined. Nuclear Research and consultancy Group (NRG in The Netherlands has been given the task of performing the corresponding neutron metrology. For this purpose, small Aluminium boxes containing a set of circular-shaped neutron activation foils have been prepared. After being irradiated for one complete reactor cycle, the sets have been successfully retrieved, followed by gamma-spectrometric measurements of the individual foils at NRG. Along with the individual activities of the foils, the reaction rates and thermal, intermediate and fast neutron fluence rates at the foil locations have been determined. These determinations include appropriate corrections for gamma self-absorption and neutron self-shielding as well as corresponding measurement uncertainties. The comparison of the NPP Monte Carlo calculations with the results of the foil measurements is done by using an individual generic MCNP model functioning as an interface and allowing the simulation of individual foil activation by predetermined neutron spectra. To summarize, the comparison between calculation and measurement serve as a sound validation of the Swiss NPP activation methodology by demonstrating a satisfying agreement between measurement and calculation. Finally, the validation offers a chance for further improvements of the existing NPP models by ensuing calibration and/or modelling optimizations for key components and structures.

Verification of nuclear effect of acoustic cavitation using fast neutron activation method

International Nuclear Information System (INIS)

Li Xinnian; Feng Tao; Fang Xiaoming; Qian Menglu; Cheng Qian

2014-01-01

14 MeV neutrons originated in acoustic cavitation fusion were determined using copper threshold detector. According to the nuclear reaction of 14 MeV neutrons with copper, the characteristic γ peaks of some radioactive nuclides were measured and the activation parameters of Cu were optimized. With neutron irradiation time of 50 min, 511 keV characteristic γ peak counts of activated copper pieces with or without ultrasonic field after 30 min and 198 min were respectively determined by NaI detector. Measurement results show that the characteristic γ peak counts of "6"2Cu and "6"4Cu can be respectively determined after 30 min and 198 min. 511 keV characteristic γ peak net count increments are positive values and statistical significance, which indicates that 14 MeV and 2.45 MeV neutron generation rates originated in fusion with ultrasound are greater than that without ultrasound in nuclear reaction liquid. These results verify the nuclear effect of acoustic cavitation (NEAC). The mechanism of NEAC nucleated by neutrons was proposed initially. (authors)

Neutron activation analysis with k{sub 0}-standardisation : general formalism and procedure

Energy Technology Data Exchange (ETDEWEB)

Pomme, S.; Hardeman, F. [Centre de l`Etude de l`Energie Nucleaire, Mol (Belgium); Robouch, P.; Etxebarria, N.; Arana, G. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Geel (Belgium)

1997-09-01

Instrumental neutron activation analysis (INAA) with k{sub 0}-standardisation is a powerful tool for multi-element analysis at a broad range of trace element concentrations. An overview is given of the basic principles, fundamental equations, and general procedure of this method. Different aspects of the description of the neutron activation reaction rate are discussed, applying the Hogdahl convention. A general activation-decay formula is derived and its application to INAA is demonstrated. Relevant k{sub 0}-definitions for different activation decay schemes are summarised and upgraded to cases of extremely high fluxes. The main standardisation techniques for INAA are discussed, emphasizing the k{sub 0}-standardisation. Some general aspects of the basic equipment and its calibration are discussed, such as the characterisation of the neutron field and the tuning of the spectrometry part. A method for the prediction and optimisation of the analytical performance of INAA is presented.

Developments in Pulsed Neutron Activation for Determination of Water Flow in Pipes

Energy Technology Data Exchange (ETDEWEB)

Mattsson, Haakan

2003-06-01

In PNA (pulsed neutron activation) it is important that the measured data can be related to the total mass flow. In this thesis two fundamental problems of the measurement technique and data treatment have been investigated: transport/mixing and background radiation. The principle of PNA is to introduce a radioactive substance into a pipe by bombarding fluid in the pipe with neutron pulses. The fluid in the pipe is activated and subsequently transported and mixed with the flow. Gamma radiation emitted from the activity is measured with one or two detectors downstream from the activation point. The time-resolved signal from the detectors is used to calculate the average velocity of the water flow. Due to the short distance between the neutron generator and the pipe the activity in the pipe becomes highly inhomogeneous. The transport and mixing of the activity were simulated using colour which was injected into the flow. It was found that the inhomogeneous activity distribution must be taken into account if the precision of the measurements is to be improved. The shape of the background in PNA affects the shape and position of the time spectrum. The nature of the background has been determined using one detector upstream and one downstream of the neutron generator. The background was shown to be caused by {sup 16}N. A method that subtracts the background from the PNA time spectrum was also developed.

Developments in Pulsed Neutron Activation for Determination of Water Flow in Pipes

International Nuclear Information System (INIS)

Mattsson, Haakan

2003-06-01

In PNA (pulsed neutron activation) it is important that the measured data can be related to the total mass flow. In this thesis two fundamental problems of the measurement technique and data treatment have been investigated: transport/mixing and background radiation. The principle of PNA is to introduce a radioactive substance into a pipe by bombarding fluid in the pipe with neutron pulses. The fluid in the pipe is activated and subsequently transported and mixed with the flow. Gamma radiation emitted from the activity is measured with one or two detectors downstream from the activation point. The time-resolved signal from the detectors is used to calculate the average velocity of the water flow. Due to the short distance between the neutron generator and the pipe the activity in the pipe becomes highly inhomogeneous. The transport and mixing of the activity were simulated using colour which was injected into the flow. It was found that the inhomogeneous activity distribution must be taken into account if the precision of the measurements is to be improved. The shape of the background in PNA affects the shape and position of the time spectrum. The nature of the background has been determined using one detector upstream and one downstream of the neutron generator. The background was shown to be caused by 16 N. A method that subtracts the background from the PNA time spectrum was also developed

Methods and procedures for evaluation of neutron-induced activation cross sections

International Nuclear Information System (INIS)

Gardner, M.A.

1981-09-01

One cannot expect measurements alone to supply all of the neutron-induced activation cross-section data required by the fission reactor, fusion reactor, and nuclear weapons development communities, given the wide ranges of incident neutron energies, the great variety of possible reaction types leading to activation, and targets both stable and unstable. Therefore, the evaluator must look to nuclear model calculations and systematics to aid in fulfilling these cross-section data needs. This review presents some of the recent developments and improvements in the prediction of neutron activation cross sections, with specific emphasis on the use of empirical and semiempirical methods. Since such systematics require much less nuclear informaion as input and much less computational time than do the multistep Hauser-Feshbach codes, they can often provide certain cross-section data at a sufficient level of accuracy within a minimum amount of time. The cross-section information that these systematics can and cannot provide and those cases in which they can be used most reliably are discussed

Methods and procedures for evaluation of neutron-induced activation cross sections

Energy Technology Data Exchange (ETDEWEB)

Gardner, M.A.

1981-09-01

One cannot expect measurements alone to supply all of the neutron-induced activation cross-section data required by the fission reactor, fusion reactor, and nuclear weapons development communities, given the wide ranges of incident neutron energies, the great variety of possible reaction types leading to activation, and targets both stable and unstable. Therefore, the evaluator must look to nuclear model calculations and systematics to aid in fulfilling these cross-section data needs. This review presents some of the recent developments and improvements in the prediction of neutron activation cross sections, with specific emphasis on the use of empirical and semiempirical methods. Since such systematics require much less nuclear informaion as input and much less computational time than do the multistep Hauser-Feshbach codes, they can often provide certain cross-section data at a sufficient level of accuracy within a minimum amount of time. The cross-section information that these systematics can and cannot provide and those cases in which they can be used most reliably are discussed.

Cold neutron prompt gamma activation analysis at NIST; A progress report

Energy Technology Data Exchange (ETDEWEB)

Paul, R L; Lindstrom, R M [National Inst. of Standards and Technology, Gaithersburg, MD (United States). Div. of Inorganic Analytical Research; Vincent, D H [Michigan Univ., Ann Arbor, MI (United States). Dept. of Nuclear Engineering

1994-05-01

An instrument for prompt gamma-ray activation analysis is now in operation at the NIST Cold Neutron Research Facility (CNRF). The cold neutron beam is relatively free of contamination by fast neutrons and reactor gamma rays, and the neutron fluence rate is 1.5 x 10 [sup 8] cm [sup -2] x s [sup -1] (thermal equivalent). As a result of a compact target-detector geometry the sensitivity is better by a factor of as much as seven than that obtained with an existing thermal instrument, and hydrogen background is a factor of 50 lower. This instrument was applied to multielement analysis of the Allende meteorite and other materials. (author) 14 refs.; 2 figs.; 1 tab.

Neutron Activation Analysis with k0 Standardization

International Nuclear Information System (INIS)

Pomme, S.

1998-01-01

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

Study on neutron activation analysis

International Nuclear Information System (INIS)

Chung, Yong Sam; Cho, Seung Yeon

1993-01-01

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

Development of Distinction Method of Production Area of Ginsengs by Using a Neutron Activation Analysis

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Jin; Chung, Yong Sam; Sun, Gwang Min; Lee, Yu Na; Yoo, Sang Ho [KAERI, Daejeon (Korea, Republic of)

2010-05-15

Distinction of production area of Korean ginsengs has been tried by using neutron activation techniques such as an instrumental neutron activation analysis (INAA) and a prompt gamma activation analysis (PGAA). A distribution of elements has varied according to the part of plant clue to the difference of enrichment effect and influence from a soil where the plants have been grown. So correlation study between plants and soil has been an Issue. In this study, the distribution of trace elements within a Korean ginseng was investigated by using an instrumental neutron activation analysis

Epithermal neutron activation analysis of food

International Nuclear Information System (INIS)

Zikovsky, L.; Soliman, K.

1999-01-01

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

Large sample neutron activation analysis: establishment at CDTN/CNEN, Brazil

Energy Technology Data Exchange (ETDEWEB)

Menezes, Maria Angela de B.C., E-mail: menezes@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Jacimovic, Radojko, E-mail: radojko.jacimovic@ijs.s [Jozef Stefan Institute, Ljubljana (Slovenia). Dept. of Environmental Sciences. Group for Radiochemistry and Radioecology

2011-07-01

In order to improve the application of the neutron activation technique at CDTN/CNEN, the large sample instrumental neutron activation analysis is being established, IAEA BRA 14798 and FAPEMIG APQ-01259-09 projects. This procedure, LS-INAA, usually requires special facilities for the activation as well as for the detection. However, the TRIGA Mark I IPR R1, CDTN/CNEN has not been adapted for the irradiation and the usual gamma spectrometry has being carried out. To start the establishment of the LS-INAA, a 5g sample - IAEA/Soil 7 reference material was analyzed by k{sub 0}-standardized method. This paper is about the detector efficiency over the volume source using KayWin v2.23 and ANGLE V3.0 software. (author)

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

International Nuclear Information System (INIS)

Hassan, A.M.

2009-01-01

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

The activation method for determining neutron spectra and fluences

International Nuclear Information System (INIS)

Hogel, J.; Vespalec, R.

1980-01-01

3 mm thick foils of 4 and 17 mm in diameter were used for measurements. NaI scintillation detectors 45 mm in diameter by 50 mm thick and 40 mm in diameter by 1 mm thick, and a Ge-Li spectrometer of 53 cm 3 in volume were used for gamma detection. A photopeak or a certain part of the integral spectrum was measured for each radionuclide. Computer code PIKAR was applied in automatic calculation of a simple gamma spectrum obtained using the semiconductor spectrometer. The FACT code was used for calculating foil activity. Codes SAND II and RFSP were used for neutron spectra unfolding. Ge-Li detector spectrometry was used for determining neutron fluence. Code FLUE was used for determining the mean value of neutron flux density and fluence. (J.P.)

Technical feasibility study for the D-T neutron monitor using activation of the flowing water

International Nuclear Information System (INIS)

Uno, Yoshitomo; Kaneko, Junichi; Nishitani, Takeo; Maekawa, Fujio; Tanaka, Teruya; Ikeda, Yujiro; Takeuchi, Hiroshi

2001-03-01

The experimental study of technical feasibility for the D-T neutron monitor using activation of the flowing water was performed at FNS/JAERI as the ITER/EDA R and D Task T499. The temporal resolution for pulsed neutrons was measured and dependence of the temporal resolution on flowing velocity was studied. The temporal resolution of 50 ms that is better than 100 ms of the requirement for ITER was achieved. We found that the temporal resolution is determined by a turbulent dispersion of the flow. The experiment for validation of the method determining the absolute D-T neutron flux was carried out by using the stainless steel (SS 316)/Water assembly to simulate the neutron field in the blanket region of ITER. The neutron emission rate measured with the water activation has a good agreement with that with the neutron yield monitor with associated α detector, and this technique shows the accuracy of the absolute neutron flux better than 10%. At the application on ITER-FEAT, the neutron activation with fluid flow has a dynamic range of 50 kW - 500 MW operation with a temporal resolution of 78 ms at the flow velocity of 10 m/s. (author)

Activation analysis with neutron generators using short-lived radionuclides

International Nuclear Information System (INIS)

Salma, I.

1993-01-01

The short half-life involves a number of important differences in production, transportation and measurement of radionuclides, and in counting statistics as compared with those in traditional activation analysis. Experiments were performed to investigate the analytical possibilities and prospective utilization of short-lived radionuclides produced by 14-MeV neutron irradiation. A rapid pneumatic transfer system for use with neutron generators was installed and applied for detecting radionuclides with a half-life from 300 ms to 30 s. The transport time for samples with a total mass of 1-4 g is between 130 and 160 ms for pressurized air of 0.1-0.4 MPa. 11 elements were studied by the conventional activation method using both a typical pneumatic transport system (run time 3 s) and the fast pneumatic transport facility. The effect of the cyclic activation technique on the elemental sensitivities was also investigated. (orig.)

Activation Inventories after Exposure to DD/DT Neutrons in Safety Analysis of Nuclear Fusion Installations.

Science.gov (United States)

Stankunas, Gediminas; Cufar, Aljaz; Tidikas, Andrius; Batistoni, Paola

2017-11-23

Irradiations with 14 MeV fusion neutrons are planned at Joint European Torus (JET) in DT operations with the objective to validate the calculation of the activation of structural materials in functional materials expected in ITER and fusion plants. This study describes the activation and dose rate calculations performed for materials irradiated throughout the DT plasma operation during which the samples of real fusion materials are exposed to 14 MeV neutrons inside the JET vacuum vessel. Preparatory activities are in progress during the current DD operations with dosimetry foils to measure the local neutron fluence and spectrum at the sample irradiation position. The materials included those used in the manufacturing of the main in-vessel components, such as ITER-grade W, Be, CuCrZr, 316 L(N) and the functional materials used in diagnostics and heating systems. The neutron-induced activities and dose rates at shutdown were calculated by the FISPACT code, using the neutron fluxes and spectra that were provided by the preceding MCNP neutron transport calculations. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Automatic sample changer for neutron activation analysis at CDTN, Brazil

International Nuclear Information System (INIS)

Aimore Dutra Neto; Oliveira Pelaes, Ana Clara; Jacimovic, Radojko

2018-01-01

An automatic sample changer was recently developed and installed in the Neutron Activation Analysis (NAA) Laboratory. The certified reference material BCR-320R, Channel Sediment, was analysed in order to verify the reliability of the results obtained by NAA, k 0 -standardisation method, using this automatic system during the gamma-ray measurement step. The results were compared to those manually obtained. The values pointed out that the automatic sample changer is working properly. This changer will increase the productiveness of the neutron activation technique applied at Nuclear Technology Development Centre, CDTN/CNEN expanding its competitiveness as an analytical technique in relation to other techniques. (author)

Future neutron data activity on the neutron source IREN

International Nuclear Information System (INIS)

Janeva, N.B.; Koyumdjieva, N.T.; Grigoriev, Y.V.; Gundorin, N.A.; Mareev, Y.D.; Kopatch, Y.N.; Pikelner, L.B.; Shvetsov, V.N.; Sedyshev, P.V.; Zeinalov, S.; Ruskov, I.N.

2011-01-01

The global energy demand continues to rise and nuclear power has a potential to be part of the solution of energy problem. Complete and accurate information about the nuclear reactions ensures developing and operating nuclear reactors to reach high efficiencies and adequate safety standards. This demands many nuclear data of improved quality, including covariance nuclear data and correlations. The new neutron source IREN (1 stage) has been put in operation at the end of 2009. The first stage includes the construction of the LUE-200 linear accelerator and non multiplying target. The first measured TOF spectra have been presented recently. The facility is in continuous completion and improvement (according to the full version in the project). The program for neutron data investigation on the IREN neutron source is in preparation. The measuring targets for neutron cross-sections TOF spectra would be selected between isotopes of construction materials, fission products and minor actinides. Now the experimental facilities are in preparation - detectors, innovative electronics equipment and systems for data acquisition and analysis. (authors)

Aspects of Low Temperature Irradiation in Neutron Activation Analysis

International Nuclear Information System (INIS)

Brune, D.

1968-08-01

Neutron irradiation of the sample while frozen in a cooling device inserted in a reactor channel has been carried out in the analysis of iodine in aqueous samples as well as of mercury in biological tissue and water. For the simultaneous irradiation of a large number of aqueous solutions the samples were arranged in a suitable geometry in order to avoid mutual flux perturbation effects. The influence of the neutron temperature on the activation process has been discussed. Potential applications of the low temperature irradiation technique are outlined

Aspects of Low Temperature Irradiation in Neutron Activation Analysis

Energy Technology Data Exchange (ETDEWEB)

Brune, D

1968-08-15

Neutron irradiation of the sample while frozen in a cooling device inserted in a reactor channel has been carried out in the analysis of iodine in aqueous samples as well as of mercury in biological tissue and water. For the simultaneous irradiation of a large number of aqueous solutions the samples were arranged in a suitable geometry in order to avoid mutual flux perturbation effects. The influence of the neutron temperature on the activation process has been discussed. Potential applications of the low temperature irradiation technique are outlined.

Research on neutron radiography in Research Reactor Institute, Kyoto University and activities related to it

International Nuclear Information System (INIS)

Fujine, Shigenori; Yoneda, Kenji

1994-01-01

The research on neutron radiography in Research Reactor Institute, Kyoto University was begun in 1974 using the E-2 experimental hole which was designed for neutron irradiation. It was reconstructed for the excellent performance as neutron radiography facility by fixing aluminum plugs, a collimator and so on. The research activities thereafter are briefly described. In 1989, the cold neutron facility was installed in the graphite thermal neutron facility, and the experiment on cold neutron radiography became feasible. The reactor in Kyoto University is of the thermal output of 5 MW, and is put to the joint utilization by universities and research institutes in whole Japan. The experimental items carried out so far are enumerated. At present, the main subjects of research are the development of the standard for establishing image evaluation method, the analysis of gas-liquid two-phase flow, the construction of the data base for the literatures and images of neutron radiography, the application of cold neutron radiography, the development of the imaging method using fast neutrons and so on. The thermal neutron radiography and the cold neutron radiography facilities of Kyoto University research reactor are described. The research and activities at Kyoto University research reactor and the investigation of problems are reported. (K.I.) 56 refs

Neutron activation analysis

International Nuclear Information System (INIS)

Okada, Yukiko

2005-01-01

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

Large Sample Neutron Activation Analysis: A Challenge in Cultural Heritage Studies

International Nuclear Information System (INIS)

Stamatelatos, I.E.; Tzika, F.

2007-01-01

Large sample neutron activation analysis compliments and significantly extends the analytical tools available for cultural heritage and authentication studies providing unique applications of non-destructive, multi-element analysis of materials that are too precious to damage for sampling purposes, representative sampling of heterogeneous materials or even analysis of whole objects. In this work, correction factors for neutron self-shielding, gamma-ray attenuation and volume distribution of the activity in large volume samples composed of iron and ceramic material were derived. Moreover, the effect of inhomogeneity on the accuracy of the technique was examined

Calculations of neutron spectra after neutron-neutron scattering

Energy Technology Data Exchange (ETDEWEB)

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

2004-09-01

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

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

International Nuclear Information System (INIS)

Diaz Rizo, O.; Herrera Peraza, E.

1996-01-01

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

Automatization of the neutron activation analysis method in the nuclear analysis laboratory

International Nuclear Information System (INIS)

Gonzalez, N.R.; Rivero, D del C.; Gonzalez, M.A.; Larramendi, F.

1993-01-01

In the present paper the work done to automatice the Neutron Activation Analysis technic with a neutron generator is described. An interface between an IBM compatible microcomputer and the equipment in use to make this kind of measurement was developed. including the specialized software for this system

Neutron Activation analysis of waste water; Analisis de aguas residuales mediante activacion neutronica

Energy Technology Data Exchange (ETDEWEB)

Hernandez H, V

1997-12-01

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

Sample design and gamma-ray counting strategy of neutron activation system for triton burnup measurements in KSTAR

Energy Technology Data Exchange (ETDEWEB)

Jo, Jungmin [Department of Energy System Engineering, Seoul National University, Seoul (Korea, Republic of); Cheon, Mun Seong [ITER Korea, National Fusion Research Institute, Daejeon (Korea, Republic of); Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr [Department of Energy System Engineering, Seoul National University, Seoul (Korea, Republic of); Hwang, Y.S. [Department of Energy System Engineering, Seoul National University, Seoul (Korea, Republic of)

2016-11-01

Highlights: • Sample design for triton burnup ratio measurement is carried out. • Samples for 14.1 MeV neutron measurements are selected for KSTAR. • Si and Cu are the most suitable materials for d-t neutron measurements. • Appropriate γ-ray counting strategies for each selected sample are established. - Abstract: On the purpose of triton burnup measurements in Korea Superconducting Tokamak Advanced Research (KSTAR) deuterium plasmas, appropriate neutron activation system (NAS) samples for 14.1 MeV d-t neutron measurements have been designed and gamma-ray counting strategy is established. Neutronics calculations are performed with the MCNP5 neutron transport code for the KSTAR neutral beam heated deuterium plasma discharges. Based on those calculations and the assumed d-t neutron yield, the activities induced by d-t neutrons are estimated with the inventory code FISPACT-2007 for candidate sample materials: Si, Cu, Al, Fe, Nb, Co, Ti, and Ni. It is found that Si, Cu, Al, and Fe are suitable for the KSATR NAS in terms of the minimum detectable activity (MDA) calculated based on the standard deviation of blank measurements. Considering background gamma-rays radiated from surrounding structures activated by thermalized fusion neutrons, appropriate gamma-ray counting strategy for each selected sample is established.

Estimation of silver in Ag-meta kaolinite by neutron activation

International Nuclear Information System (INIS)

Daniels, E.A.; Rao, S.M.

1981-01-01

The present work is based on the neutron activation of Ag-meta kaolinite for the determination of its silver content from the β-activity of the compound using standard tables which showed the percentage of silver in mixtures of silver nitrate and meta kaolinite of known composition against β-activity of the mixture activated under identical conditions. (author)

Neutron activation analysis applied to nutritional and foodstuff studies

International Nuclear Information System (INIS)

Maihara, Vera A.; Santos, Paola S.; Moura, Patricia L.C.; Castro, Lilian P. de; Avegliano, Roseane P.

2009-01-01

Neutron Activation Analysis, NAA, has been successfully used on a regularly basis in several areas of nutrition and foodstuffs. NAA has become an important and useful research tool due to the methodology's advantages. These include high accuracy, small quantities of samples and no chemical treatment. This technique allows the determination of important elements directly related to human health. NAA also provides data concerning essential and toxic concentrations in foodstuffs and specific diets. In this paper some studies in the area of nutrition which have been carried out at the Neutron Activation Laboratory of IPEN/CNEN-SP will be presented: a Brazilian total diet study: nutritional element dietary intakes of Sao Paulo state population; a study of trace element in maternal milk and the determination of essential trace elements in some edible mushrooms. (author)

Analysis of medicinal plant extracts by neutron activation method

International Nuclear Information System (INIS)

Vaz, Sandra Muntz

1995-01-01

This dissertation has presented the results from analysis of medicinal plant extracts using neutron activation method. Instrumental neutron activation analysis was applied to the determination of the elements Al, Br, Ca, Ce, Cl, Cr, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc and Zn in medicinal extracts obtained from Achyrolcline satureoides DC, Casearia sylvestris, Centella asiatica, Citrus aurantium L., Solano lycocarpum, Solidago microglossa, Stryphnondedron barbatiman and Zingiber officinale R. plants. The elements Hg and Se were determined using radiochemical separation by means of retention of Se in HMD inorganic exchanger and solvent extraction of Hg by bismuth diethyl-dithiocarbamate solution. Precision and accuracy of the results have been evaluated by analysing reference materials. The therapeutic action of some elements found in plant extracts analyzed was briefly discussed

Neutron activation analysis of certified samples by the absolute method

Science.gov (United States)

Kadem, F.; Belouadah, N.; Idiri, Z.

2015-07-01

The nuclear reactions analysis technique is mainly based on the relative method or the use of activation cross sections. In order to validate nuclear data for the calculated cross section evaluated from systematic studies, we used the neutron activation analysis technique (NAA) to determine the various constituent concentrations of certified samples for animal blood, milk and hay. In this analysis, the absolute method is used. The neutron activation technique involves irradiating the sample and subsequently performing a measurement of the activity of the sample. The fundamental equation of the activation connects several physical parameters including the cross section that is essential for the quantitative determination of the different elements composing the sample without resorting to the use of standard sample. Called the absolute method, it allows a measurement as accurate as the relative method. The results obtained by the absolute method showed that the values are as precise as the relative method requiring the use of standard sample for each element to be quantified.

Epithermal neutron activation analysis using a boron carbide irradiation filter

International Nuclear Information System (INIS)

Ehmann, W.D.; Brueckner, J.

1980-01-01

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

Neutron activation analysis of trace elements in foodstuffs

International Nuclear Information System (INIS)

Schelenz, R.; Fischer, E.

1976-05-01

A neutron activation method for multielement determination in biological material was developed. The individual steps of the method include radiochemical processing as well as nondestructive techniques. In order to develop a high resolution gamma spectrometric method the indispensable assumptions were the application of Ge(Li)-semiconductor detectors, multi-channel pulse height analyzers and the use of electronic data evaluation with mini-computers for the automatic evaluation of complex gamma spectra. After radiochemical separation (RNAA) 33 elements can be determined in biological materials and by application of nondestructive, purely instrumental techniques (INAA) 25 elements. The time required for the analysis of 33 elements can be determined in biological materials and by application of nondestructive, purely instrumental techniques (INAA) 25 elements. The time required for the analysis of 33 elements is 4 days. The neutron activation method is used routinely for the determination of trace elements in foodstuffs and in the field of nutrition research. (orig.) [de

Provenience studies using neutron activation analysis: the role of standardization

International Nuclear Information System (INIS)

Harbottle, G.

1980-01-01

This paper covers the historical background of chemical analysis of archaeological artifacts which dates back to 1790 to the first application of neutron activation analysis to archaeological ceramics and goes on to elaborate on the present day status of neutron activation analysis in provenience studies, and the role of standardization. In principle, the concentrations of elements in a neutron-activated specimen can be calculated from an exact knowledge of neutron flux, its intensity, duration and spectral (energy) distribution, plus an exact gamma ray count calibrated for efficiency, corrected for branching rates, etc. However, in practice it is far easier to compare one's unknown to a standard of known or assumed composition. The practice has been for different laboratories to use different standards. With analyses being run in the thousands throughout the world, a great benefit would be derived if analyses could be exchanged among all users and/or generators of data. The emphasis of this paper is on interlaboratory comparability of ceramic data; how far are we from it, what has been proposed in the past to achieve this goal, and what is being proposed. All of this may be summarized under the general heading of Analytical Quality Control - i.e., how to achieve precise and accurate analysis. The author proposes that anyone wishing to analyze archaeological ceramics should simply use his own standard, but attempt to calibrate that standard as nearly as possible to absolute (i.e., accurate) concentration values. The relationship of Analytical Quality Control to provenience location is also examined

Total body-calcium measurements: comparison of two delayed-gamma neutron activation facilities

International Nuclear Information System (INIS)

Ma, R.; Ellis, K.J.; Shypailo, R.J.; Pierson, R.N. Jr.

1999-01-01

This study compares two independently calibrated delayed-gamma neutron activation (DGNA) facilities, one at the Brookhaven National Laboratory (BNL), Upton, New York, and the other at the Children's Nutrition Research Center (CNRC), Houston, Texas that measure total body calcium (TBCa). A set of BNL phantoms was sent to CNRC for neutron activation analysis, and a set of CNRC phantoms was measured at BNL. Both facilities showed high precision (<2%), and the results were in good agreement, within 5%. (author)

Procedures for multielement analysis using high-flux fast-neutron activation

International Nuclear Information System (INIS)

Williams, R.E.; Hopke, P.K.; Meyer, R.A.

1981-06-01

Improvements have been made in the rabbit system used for multi-element fast-neutron activation analysis at the Lawrence Livermore National Laboratory Rotating Target Neutron Source, RTNS-I. Procedures have been developed for the analysis of 20 to 25 elements in samples with an inorganic matrix and 10 to 15 elements in biological samples, without the need for prohibitively expensive, long irradiations. Results are presented for the analysis of fly ash, orchard leaves, and bovine liver

Californium-252 neutron activation analysis of high-level processed nuclear tank waste

International Nuclear Information System (INIS)

Troyer, G.L.; Purcell, M.A.

2000-01-01

The basis for production assessment of the vitrification of Hanford nuclear fuel reprocessing wastes will be high-precision measurements of the elemental sodium content. However, the chemical analysis of both radioactive and nonradioactive components in nuclear waste can be challenged by high radiation dose rates. The dose rates compromise many analytical techniques as well as pose personnel dosimetry risks. In many cases, reduction of dose rates through dilution compromises the precision and sensitivity for certain key components. The use of neutron activation analysis (NAA) provides a method of analysis that avoids the need for dilutions or extensive sample preparation. These waste materials also contain trace quantities of fissionable isotopes, which, through neutron activation, can be estimated by delayed neutron counting of fissioned fragments

Determination of oxygen content in steel using activation analysis with 14 MeV neutron

International Nuclear Information System (INIS)

Calado, C.E.

1978-01-01

In the quantitative analysis of oxygen in steel by fast neutron activation analysis the oxygen content is evaluated from the measured activity of 16 N produced. Steel s mples are irradiated in 14 MeV neutron flux. After irradiation the samples are pneumatically transfered to the counting terminal where activity is measured. Oxygen concentrations, are obtained by comparison with standards of specified oxygen content [pt

Records in ultra low radioactivity measurements with neutron activation analysis

International Nuclear Information System (INIS)

Hentig, R. von; Goldbrunner, T.; Angloher, G.; Feilitzsch, F. von

1999-01-01

Neutron Activation Analysis has emerged to be an analytical method sensitive enough to detect fg/g traces of unstable primordial nuclides in complex matrices. Especially low count rate experiments in the field of solar neutrino physics and dark matter search can profit from the detection capabilities of this method which had been unattained so far. This gain in sensitivity has been achieved by combining neutron activation, radiochemical separation methods, and efficient low level counting systems at the new underground laboratory of the accelerator laboratory in Garching. Recent improvements which have been made in the purification and analysis of the liquid scintillator, as foreseen for the solar neutrino experiment BOREXINO, are being presented as an example in this paper

On-line neutron activation analyzers

International Nuclear Information System (INIS)

Flahaut, V.; Colmon, A.

1999-01-01

A neutronic analyser has been designed to determine the composition of the flow of raw materials entering a cement factory on the conveyor belt. This new system gives a reliable analysis of the whole cargo that outdates the sampling or the usual surface analysis based on fluorescence spectrometry. The accuracy is about 1%.The neutrons interact with the materials on an average depth of 25 cm and are absorbed by nuclei, these nuclei produce photons whose energy is characteristic of the chemical element itself. The composition can be deduced by measuring the number of photons emitted and their energy. The analysis is made on-line and can concern the search for about 10 compounds. In the case of cement the list of compounds is: SiO 2 , CaO, Al 2 O 3 , Fe 2 O 3 , MgO, Na 2 O, TiO 2 , S, Mn 2 O 3 , K 2 O, and H 2 O. The neutron generator involves a deuterium ion source whose deuterium ions are accelerated by means of an electrical field and impinge on a tritiated target, the nuclear reactions between deuterium and tritium produce 14 MeV neutrons. This neutron analysing technique can be adapted to any need of on-line composition determination. (A.C.)

NAC, Neutron Activation Analysis and Isotope Inventory

International Nuclear Information System (INIS)

1995-01-01

1 - Description of program or function: NAC was designed to predict the neutron-induced gamma-ray radioactivity for a wide variety of composite materials. The NAC output includes the input data, a list of all reactions for each constituent element, and the end-of-irradiation disintegration rates for each reaction. NAC also compiles a product isotope inventory containing the isotope name, the disintegration rate, the gamma-ray source strength and the absorbed dose rate at 1 meter from an unshielded point source. The induced activity is calculated as a function of irradiation and decay times; the effect of cyclic irradiation can also be calculated. 2 - Method of solution: The standard neutron activation and decay equations are programmed. A data library is supplied which contains target element names, atomic densities, reaction indices, individual reactions and reaction parameters, and product isotopes and gamma energy yields. 3 - Restrictions on the complexity of the problem: Each composite material may consist of up to 20 different elements and up to 20 different decay times may be included. Both limits may be increased by the user by increasing the appropriate items in the dimension statement

Large sample neutron activation analysis of a reference inhomogeneous sample

International Nuclear Information System (INIS)

Vasilopoulou, T.; Athens National Technical University, Athens; Tzika, F.; Stamatelatos, I.E.; Koster-Ammerlaan, M.J.J.

2011-01-01

A benchmark experiment was performed for Neutron Activation Analysis (NAA) of a large inhomogeneous sample. The reference sample was developed in-house and consisted of SiO 2 matrix and an Al-Zn alloy 'inhomogeneity' body. Monte Carlo simulations were employed to derive appropriate correction factors for neutron self-shielding during irradiation as well as self-attenuation of gamma rays and sample geometry during counting. The large sample neutron activation analysis (LSNAA) results were compared against reference values and the trueness of the technique was evaluated. An agreement within ±10% was observed between LSNAA and reference elemental mass values, for all matrix and inhomogeneity elements except Samarium, provided that the inhomogeneity body was fully simulated. However, in cases that the inhomogeneity was treated as not known, the results showed a reasonable agreement for most matrix elements, while large discrepancies were observed for the inhomogeneity elements. This study provided a quantification of the uncertainties associated with inhomogeneity in large sample analysis and contributed to the identification of the needs for future development of LSNAA facilities for analysis of inhomogeneous samples. (author)

Evaluation of the U-Pu residual mass from spent fuel assemblies with passive and active neutronic methods

International Nuclear Information System (INIS)

Bignan, G.; Martin-Deidier, L.

1991-01-01

The interpretation of passive and active neutronic measurements to evaluate the U-Pu residual mass in spent fuel assemblies is presented as follows: passive neutron measurements are well correlated to the plutonium mass, active neutron measurements give information linked to the fissile mass content of the assembly ( 235 U + 239 Pu + 241 Pu) and, using the passive neutron measurement, lead to the 235 U mass content of the assemblies

Analysis of human enamel and dentine by neutron activation analysis

International Nuclear Information System (INIS)

Soares, Marco A.B.

2005-01-01

Determination of trace elements in dental tissues has been of great interest to study the correlation between element composition and caries as well as food habits of individuals. In the present study dentine and enamel samples from healthy individuals were analysed by neutron activation analysis. The teeth were provided form dental clinics, and they were previously washed using purified water and acetone. Then they were dried at 40 deg C and ground in a agate mortar. The samples and element standards were irradiated with thermal neutrons at the IEA-R1 nuclear reactor. Long irradiations of 8 h under thermal neutron flux of 5x10 12 n cm -2 s -1 were used for Ca, Na, Sr and Zn determinations. In short irradiations of 15 s and under neutron flux of 10 12 n cm -2 s -1 the elements Mg, Mn, Na e Sr were determined. The induced gamma activities of the samples and standards were measured using a hyperpure Ge detector coupled to a gamma ray spectrometer. Elemental concentrations were calculated by comparative method. Results obtained showed that Ca, Mg and Na are present in both tissues at the level of percentages and the elements Mn, Sr and Zn at the μg g -1 levels. For quality control of the results the certified reference materials NIST 1400 Bone Ash and NIST 1486 Bone Meal were analysed. (author)

Investigation of distribution of elements in a Korean ginseng by using a neutron activation method

Energy Technology Data Exchange (ETDEWEB)

Lee, Yu Na; Sun, Gwang Min; Chung, Yong Sam; Kim, Young Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2009-10-15

The Distinction of production areas of Korean ginsengs has been tried by using neutron activation techniques such as an instrumental neutron activation analysis (INAA) and a prompt gamma activation analysis (PGAA). This study was done as a part of those efforts. As is well known, the distribution of elements varies according to the part of plant due to the difference of enrichment effect and influence from a soil where the plants have been grown. So a correlation study between plants and soil is an important issue. In this study, the distribution of trace elements within a Korean ginseng was investigated by using an instrumental neutron activation analysis.

Simulation for sodium-24 production using cyclic neutron activation analysis

International Nuclear Information System (INIS)

Ahamed, O. M. H.

2012-04-01

The cyclic neutron activation analysis is a method for elemental analysis which is preferred to use short-lived radio-nuclides. In recent years this method became a new application for radioisotope production especially in low power research reactors. In this study instrumental cyclic neutron activation analysis was used for 2 4N a production using 2 3N a (n, γ) 2 4N a reaction. The simplified westcott convention method is used neutron activation analysis in a research reactor. The method takes into account all corrections that can affect that yield created. In this work a model was devolving for calculations through this simplified Westcott convention method by using C++ program and selecting good parameters that can produce the expected activity. The simulation is used for the theoretical yield calculated has been validated by data from the 1 77L u production used for theoretical yield which it gives the approached result had been obtained by FORTRAN 90 from literature (8). The results were achieved for expected activity at full power (1 x 10 1 2n cm -2 s - 1 ) and half power (5 x 10 11 cm -2 s -1 ) for research reactor MNSR. The activity at full power was equal to about twice the activity at half power ( 49±7, 24.9 ± MBq/g), respectively. The irradiation parameters selected were irradiation time 4 min and decay time 12 min. Sample weight was 50 mg at 12 numbers of cycles, when the K-factor was equal to 1.74. This work is considered as first step for production of 2 4N a which can use such parameters experimentally. It is then possible to compare the expected activity with measured activity. (Author)

Storage and pre-neutron-activation-analysis treatment for trace-element analysis in urine

International Nuclear Information System (INIS)

Blotcky, A.J.; Rack, E.P.

1985-01-01

The problems regarding storage and pre-neutron-activation-analysis treatment for the elements aluminum, calcium, vanadium, selenium, copper, iodine, zinc, manganese, and magnesium in a urine matrix are reviewed. The type of collection and storage procedure and pre-neutron activation analysis treatment of urine depend on the specific trace element; that is, its inherent physical and chemical properties. Specifically polyethylene in teflon containers are the most suitable for general determinations. Whether any preservative is added would depend upon the stability of the trace element and its tendency for surface adsorption. Preferably, preservatives should contain no radioactivatable elements for maximum efficacy. Freeze drying or packing urine shipments under dry ice needs to be explored on an individual basis. Each pre- or post-neutron activation analysis treatment is specific and optimized for the trace element analyzed

Research and development activities of the Neutron Physics Division for the period January 1980 - December 1980

International Nuclear Information System (INIS)

Basu, T.K.; Bhakay-Tamhane, S.

1981-01-01

The highlights of the research and development (R and D) activities of the Neutron Physics Division of the Bhabha Atomic Research Centre, Bombay, during January - December 1980 are summarised. The R and D activities are in the fields of critical and subcritical fission systems, the plasma focus device, applied neutron physics, neutron and X-ray crystallography, materials physics and seismology. (M.G.B.)

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

Science.gov (United States)

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

2018-04-01

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

Neutron activation analysis of absolutely-dated tree rings

International Nuclear Information System (INIS)

Uenlue, K.; Hauck, D.K.; Kuniholm, P.I.; Chiment, J.J.

2005-01-01

Gold concentration was determined for dendrochronologically-dated wood samples using neutron activation analysis (NAA) and correlation sought with known environmental changes, e.g., volcanic activities, during historic periods. Uptake of gold is sensitive to soil pH for many plants. Data presented are from a single, cross-dated tree that grew in Greece. Using NAA, gold was measured with parts-per-billion sensitivity in individual tree rings from 1411 to 1988 AD. (author)

Absorption and activation techniques in measurements of fast-neutron capture cross sections

International Nuclear Information System (INIS)

Bergqvist, I.

1982-01-01

The absorption and activation methods have been applied for a long time to systematic studies of fast neutron capture cross sections. Both methods are simple in principle but difficult in practice. The simplicity should ensure a wider use of the methods in particular for problems which may be complicated to approach with other methods. The difficulties encountered in absorption measurements are related to multiple scattering and resonance shielding effects. In activation experiments the influence of secondary low-energy neutrons causes the main problems

Neutron activation: an invaluable technique for teaching applied radiation

International Nuclear Information System (INIS)

Trainer, Matthew

2002-01-01

This experiment introduces students to the important method of neutron activation. A sample of aluminium was irradiated with neutrons from an isotropic 241 Am-Be source. Using γ-ray spectroscopy, two radionuclide products were identified as 27 Mg and 28 Al. Applying a cadmium cut-off filter and an optimum irradiation time of 45 min, the half-life of 27 Mg was determined as 9.46±0.50 min. The half-life of the 28 Al radionuclide was determined as 2.28±0.10 min using a polythene moderator and an optimum irradiation time of 10 min. (author)

Determination of cadmium in environmental materials by fast neutron activation analysis

International Nuclear Information System (INIS)

Esprit, M.; Vandecasteele, C.; Hoste, J.

1986-01-01

Cadmium is determined by activation analysis with fast neutrons, obtained by irradiation of a thick beryllium target with 14.5-MeV deuterons. Cadmium-111m is separated by liquid-liquid extraction with zinc diethyldithiocarbamate in chloroform and measured with a Ge(Li) γ-spectrometer. For low concentrations, cadmium is precipitated as cadmium ammonium phosphate after the extraction. NBS and BCR reference materials were analyzed: for concentrations between 3 and 500 μg g -1 , the relative standard deviation ranges from 5 to 3%. The results obtained for sewage sludge are compared with those obtained by reactor neutron activation analysis. (Auth.)

Neutronic activation analysis of antique ceramics. Groups and differenciation

International Nuclear Information System (INIS)

Widemann, F.

1975-01-01

Different techniques for clay analysis in view of studying the origin of ceramics are exposed. The element abundance is measured by X-ray fluorescence analysis or by neutron activation analysis. Comparative tables of the results are established [fr

Neutron activation analysis at CDTN/CNEN using the IPR-R1 Triga Mark I reactor

International Nuclear Information System (INIS)

Menezes, Maria Angela de B.C.; Maretti Junior, Fausto; Kastner, Geraldo Frederico; Amaral, Angela Maria; Souza, Wagner de

2009-01-01

This paper describes in summary the activities developed by the Laboratory for Neutron Activation Analysis since the starting up of the IPR-R1 TRIGA Mark I research reactor in 1960. This Laboratory is located at Centro de Desenvolvimento da Tecnologia Nuclear (Nuclear Technology Development Centre) / Comissao Nacional de Energia Nuclear (Brazilian Commission for Nuclear Energy), CDTN/CNEN. The activities of the Laboratory comprise the delayed fission neutron activation analysis, instrumental (comparative and parametric methods) and radiochemical / chemical methods. These methods are responsible for significant percentage of CDTN's analytical demand, meeting the clients' analytical needs and researches developed by the Laboratory, by CDTN and by other institutions. Over the years the work has been linked to the goals of the country and the institutions. Nowadays the neutron activation analysis is responsible for 70% of the analytical demand and the k 0 - Instrumental method for 80% of this demand answering clients' request and researches. In Brazil, CDTN is the only Institute that fully masters the Instrumental Neutron Activation Analysis k 0 -method using its own nuclear reactor. (author)

In vivo neutron activation at Toronto 1967-1981

International Nuclear Information System (INIS)

Harrison, J.E.; McNeill, K.G.

1986-01-01

Since the inception of work on in vivo neutron activation analysis at Toronto in 1967, the project has grown until these procedures are in routine diagnostic use at the Toronto General Hospital. Approximately 300 calcium tests and 600 nitrogen tests are carried out each year. Cadmium tests are also available. (author)

Determination of sodium in pharmaceuticals by neutron activation analysis

International Nuclear Information System (INIS)

Kanias, G.D.

1985-01-01

A simple, fast and accurate neutron activation analysis method for determination of Na in drugs concerning either active compound or total content was developed. The examined dosage forms consisted of 10 injectable ampoules and 10 bottles of oral solutions. The irradiation of samples and standards was carried out in the rotation system of the Reactor of Nuclear Research Center Democritos with maximal neutron flux of 2,9.10 13 n.cm -2 .sec -1 . Gamma-ray spectrometry of the irradiated samples and standards was accomplished with a coaxial Ge(Li) detector series Win 15 with an efficiency of 15% connected to an Ino-Tech 1024 channel analyser (Model IT 5200). The accuracy and precision of the method are found to be very high and therefore it could be established as an official one for the determination of sodium in parmaceuticals

Multielement analysis of biological standards by neutron activation analysis

International Nuclear Information System (INIS)

Nadkarni, R.A.

1977-01-01

Up to 28 elements were determined in two IAEA standards: Animal Muscle H4 and Fish Soluble A 6/74, and three NBS standards: Spinach: SRM-1570, Tomato Leaves: SRM-1573 and Pine Needles: SRM-1575 by instrumental neutron-activation analysis. Seven noble metals were determined in two NBS standards: Coal: SRM-1632 and Coal Fly Ash: SRM-1633 by radiochemical procedure while 11 rare earth elements were determined in NBS standard Orchard Leaves: SRM-1571 by instrumental neutron-activation analysis. The results are in good agreement with the certified and/or literature data where available. The irradiations were performed at the Cornell TRIGA Mark II nuclear reactor at a thermal neutron flux of 1-3x10 12 ncm -2 sec -1 . The short-lived species were determined after a 2-minute irradiation in the pneumatic rabbit tube, and the longer-lived species after an 8-hour irradiation in the central thimble facility. The standards and samples were counted on coaxial 56-cm 3 Ge(Li) detector. The system resolution was 1.96 keV (FWHM) with a peak to Compton ratio of 37:1 and counting efficiency of 13%, all compared to the 1.332 MeV photopeak of Co-60. (T.I.)

Technical Aspect for Operating Portable Prompt Gamma Neutron Activation Analysis (PGNAA) on Terengganu Inscribed Stone

International Nuclear Information System (INIS)

Rasif Mohd Zain; Hearie Hassan; Roslan Yahya

2015-01-01

Prompt Gamma Neutron Activation analysis (PGNAA) is a type of neutron activation analysis which can determined element with nearly no gamma ray decay after being irradiated by neutron sourced. Thus, element that cannot be determined by the conventional NAA for example H, B, N, Si and Cd, can be determine by PGNAA. This paper focuses on the technical working procedure for operating portable PGNAA in field work. The device is designed as a portable non-destructive investigation tool applying an isotopic neutron source (Cf-252) and a gamma-ray spectroscopy system for in-situ investigation. The studied have been carried out on Terengganu inscribed stone at Terengganu State Museum. (author)

'ACTIV' - a package of codes for charged particle and neutron activation analysis

International Nuclear Information System (INIS)

Cincu, Em.; Alexandreanu, B.; Manu, V.; Moisa, V.

1997-01-01

The 'ACTIV' Program is an advanced software package dedicated to applications of the thermal neutron and charged particle activation (NAA and CPA) induced reactions. The program is designed to run on personal computers compatible IBM PC-Models XT/AT, 286 or more advanced, operating under DOS version 5.0 or later, on systems with minimum 5 MB of hard disk memory. The package consists of 6 software modules and a Nuclear Data Base comprising physical, nuclear reaction and decay data for: thermal neutron, proton, deuteron and α-particle induced reactions on 15 selected metallic elements; the nuclear reaction data corresponds to the energy range (5-100) MeV. In the first version - ACTIV 1.0 - the set of input data concerns: the sample type, irradiation and measurement conditions, the γ-ray spectrum identification code, selected detection efficiency calibration curve, selected radionuclides, selected standardization method for elemental analysis, version of results. At present, the 'ACTIV' package comprises 6 soft modules for processing the experimental data, which ensure computation of the quantities: radionuclide activities, activation yield data (case of CPA) and elemental concentration by relative and absolute standardization methods. Recently, the software designed to processing complex γ-ray spectra was acquired and installed on our PC 486 (8 MB RAM, 100 MHz). The next step in developing the 'ACTIV' program envisages improving the existing computing codes, completing the data libraries, incorporating a new soft for the direct use of the 'Quantum TM MCA' data, developing modules dedicated to uncertainty computation and optimization of the activation experiments

Nondestructive assay of subassemblies of various spent or fresh fuels by active neutron interrogation

International Nuclear Information System (INIS)

Ragan, G.L.; Ricker, C.W.; Chiles, M.M.; Ingersoll, D.T.; Slaughter, G.G.

1979-01-01

Recent studies show that subassemblies containing various spent fuels could be assayed rapidly and accurately by a nondestructive assay system using active neutron interrogation and prompt-neutron detection. Subassembly penetration is achieved by 24-keV (Sb--Be) interrogation neutrons; the spent-fuel neutron background is overridden by using strong interrogating sources and prompt-neutron signals, and background gammas are absorbed by lead. Experiments have demonstrated the potential for assaying with better than 5% accuracy, three spent plutonium-fueled subassemblies per hour. Calculations, validated by experiments, predict even better performance for fresh or uranium-fueled subassemblies; several performance estimates are given

Measurement and Analysis of Activation Induced in Lanthanum, Erbium and Tantalum by Fusion Peak Neutrons

International Nuclear Information System (INIS)

Klix, A.; Eichin, R.; Freiesleben, H.; Schomburg, K.; Seidel, K.; Unholzer, S.; Forrest, R.A.

2006-01-01

The large fluxes of neutrons in the materials of a fusion device during operation produce activation that is relevant to operational safety and decommissioning. Nuclides with a broad range of half-lives have to be included in the corresponding analyses. The activity with decay times ranging from the order of magnitude of minutes to weeks is of interest with respect to heat production and shut-down dose rates, whereas the long-term activity determines the waste management. The activity is mainly produced by two components of the neutron flux spectrum, by thermal neutrons and by the 14-MeV D-T fusion neutrons. Analyses of the material activation rely on calculations with inventory codes and libraries containing activation and decay data. To gain trust in the results of such calculations data and codes have to be validated experimentally. In the present work, the European Activation System (EASY, inventory code FISPACT and data library EAF) was tested in benchmark experiments on Lanthanum, Erbium and Tantalum. They are constituents of fusion reactor structural materials such as EUROFER and insulating coatings for liquid breeder systems. Small samples of the materials were irradiated in a D-T neutron field. The gamma-radioactivity following irradiation was measured several times during decay and nuclide activities were derived. For each of the measured activities the corresponding value was calculated with EASY, and the calculated-to-experimental ratios (C/E) were determined. The nuclear reactions producing the activities were also analysed. The C/E ratios obtained for the individual activities will be used for discussing the activation performance and the contact dose rate of the materials at fusion power plant conditions. (author)

Aborption and activation techniques in measurements of fast-neutron capture cross sections

International Nuclear Information System (INIS)

Bergqvist, I.

1982-01-01

The absorption and activation methods have been applied for a long time to systematic studies of fast neutron capture cross sections. Both methods are simple in principle but difficult in practice. The simplicity should ensure a wider use of the methods in particular for problems which may be complicated to approach with other methods The difficulties encountered in absorption measurements are related to multiple scattering and resonance shielding effects. In activation experiments the influence of secondary low-energy neutrons c causes the main problems. (Author)

Development of active neutron interrogation techniques at Harwell

International Nuclear Information System (INIS)

Armitage, B.H.; Chard, P.M.J.; Packer, T.W.; Swinhoe, M.T.; Syme, D.B.

1990-01-01

Active neutron interrogation techniques capable of measuring the fissile content of a range of waste drum sizes and contents have been developed at Harwell. This paper describes measurements which have been made to investigate the behaviour of these assay systems for the difficult case of concreted waste in a heterogeneous matrix. The drums have been measured using a Cf shuffler and a differential die-away system, with supporting information obtained from a segmented gamma-scanner. Good correspondence has been observed between the two different neutron interrogation techniques. It was concluded that the measurement of highly heterogeneous wastes is likely to be more effective if calibration can be undertaken with representative artificial matrices. Further measurement and analysis remains to be undertaken

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

International Nuclear Information System (INIS)

Erdtmann, G.

1993-08-01

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

Neutron activation analysis in reconnaissance geochemical survey of Northwestern Mindoro

International Nuclear Information System (INIS)

Santos, G. Jr.; Fernandez, L.G.

1987-01-01

Instrumental neutron activation analysis (NAA) technique was used to analyze stream sediments collected in Northwestern Mindoro. The concentration levels of 18 elements were determined. It was noted that NAA is suitable for the determination of rare earth, gold, arsenic and cobalt among others because of favorable high neutron cross sections. Samples collected in regional reconnaissance geochemical surveys could be analyzed usng NAA technique to complement other non-nuclear techniques, such as atomic absorption and X-ray fluorescence analysis. (Author). 11 figs.; 2 tabs.; 12 refs

Trace element analysis of common salt using neutron activation analysis

International Nuclear Information System (INIS)

Usman, K.

1993-01-01

Instrumental Fast Neutron Activation Analysis (IFNAA) technique has been used in the qualitative and quantitative determination of the impurity elements in common salt. Samples of the different types of common salt processed in Nigeria and some of those imported into the country were used. The type A711 KAMAN neutron generator and a high-purity Germanium (HpGe) gamma spectrometer available at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria has been used. The ORTEC ADCAM 100 Emulation Software (Maestro) was used in the qualitative measurement of the detected elements. The G.R.G Activation Analysis System by G. R. Gilmore, 1987, was used in the quantitative determination of the elements detected by relative method. Aluminium and arsenic were detected and measured

Toxicological applications of neutron-activation analysis

International Nuclear Information System (INIS)

Cross, J.D.; Dale, I.M.; Smith, H.

1975-01-01

Thermal neutron-activation analysis is recognised as a useful tool for trace element studies in toxicology. This paper describes some recent applications of the technique to three elements when ingested by people in excess of normal intake Two of the elements (copper and chromium) are essential to life and one (bromine) is as yet unclassified. Three deaths were investiagted and trace element levels compared with normal levels from healthy subjects in the same geographical area who had died as a result of violence. (author)

Nuclear and activation characteristics of materials in 14.1-MeV and 2.5-MeV neutron field

International Nuclear Information System (INIS)

Seki, Yasushi; Takeyasu, Yuuichi.

1988-11-01

The nuclear and activation characteristics of various materials and elements of interest in terms of fusion reactor design are calculated and the results are graphically shown. The elements and materials are placed in a simple geometry modelling a blanket and shield of a fusion reactor. The neutrons with 14.1-MeV and 2.5-MeV energy are generated from the region represented as D-T and D-D plasma, respectively. The following activation characteristics after neutron irradiation are shown for each material and element; 1. Time evolution of induced activity, 2. Time evolution of decay heat, 3. Delayed gamma-ray dose distribution, 4. Decay heat distribution. In addition to the above activation characteristics, nuclear characteristics during the neutron irradiation, e.g. neutron energy spectra, neutron and gamma-ray flux distribution, nuclear heating distributions, and neutron and gamma-ray dose rate are also shown. (author)

Neutron activation analysis method to determination vitamine B_1_2 (sianokobalamin) in pharmaceutical product

International Nuclear Information System (INIS)

Titiek Martati; June Mellawati

2010-01-01

Analysis of vita mine 812 in pharmaceutical preparations can be done by neutron activation method, because one molecule of vita mine 812 contains one atom of Co (4.35 %). The aim of research to know the ability of neutron activation method to analyze pharmaceutical preparations of vitamine 812 by test the precision and accuracy methods. It is expected that the method of neutron activation analysis can be an alternative method in the determination of vitamine 812 in pharmaceutical preparations. Samples were irradiated using thermal neutrons in the reactor during 30 minutes Siwabessy GA, and based on n, gamma reaction, the "6"0CO isotope formed then be identified using Gamma Spectrometer at 1173.5 and 1332.4 keV energy. Vitamine 812 concentration was obtained by calculating the ratio of vitamine 812 molecule to molecule Co. The results showed that the neutron activation method is good for determining 8_1_2 vitamin in low concentration (≥ 200 mg), but not for high concentrations ( ≥ 5000 mg). This method has a 99.11 to 99.52 % accuracy, and 96.52 to 104.95 % precision with a detection limit measures of vita mine 812184.36 mg. Recovery test obtained ranged between 98.19 to 101.07 % of vitamine 812 compared to levels specified in the label, so that still recommend the requirements of British Pharmacopoeia 2009 and the United States Pharmacopoeia 29. (author)

Research reactor operations for neutron activation analysis

International Nuclear Information System (INIS)

Tv'ehlov, Yu.

2002-01-01

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

PROMETHEE: An Alpha Low Level Waste Assay System Using Passive and Active Neutron Measurement Methods

International Nuclear Information System (INIS)

Passard, Christian; Mariani, Alain; Jallu, Fanny; Romeyer-Dherbey, Jacques; Recroix, Herve; Rodriguez, Michel; Loridon, Joel; Denis, Caroline; Toubon, Herve

2002-01-01

The development of a passive-active neutron assay system for alpha low level waste characterization at the French Atomic Energy Commission is discussed. Less than 50 Bq[α] (about 50 μg Pu) per gram of crude waste must be measured in 118-l 'European' drums in order to reach the requirements for incinerating wastes. Detection limits of about 0.12 mg of effective 239 Pu in total active neutron counting, and 0.08 mg of effective 239 Pu coincident active neutron counting, may currently be detected (empty cavity, measurement time of 15 min, neutron generator emission of 1.6 x 10 8 s -1 [4π]). The most limiting parameters in terms of performances are the matrix of the drum - its composition (H, Cl...), its density, and its heterogeneity degree - and the localization and self-shielding properties of the contaminant

Applicability of neutron activation analysis to geological samples

Energy Technology Data Exchange (ETDEWEB)

Ebihara, Mitsuru [Tokyo Metropolitan Univ., Graduate School of Science, Tokyo (Japan)

2003-03-01

The applicability of neutron activation analysis (NAA) to geological samples in space is discussed by referring to future space mission programs, by which the extraterrestrial samples are to be delivered to the earth for scientific inspections. It is concluded that both destructive and non-destructive NAA are highly effective in analyzing these samples. (author)

Applicability of neutron activation analysis to geological samples

International Nuclear Information System (INIS)

Ebihara, Mitsuru

2003-01-01

The applicability of neutron activation analysis (NAA) to geological samples in space is discussed by referring to future space mission programs, by which the extraterrestrial samples are to be delivered to the earth for scientific inspections. It is concluded that both destructive and non-destructive NAA are highly effective in analyzing these samples. (author)

Probing Trace-elements in Bitumen by Neutron Activation Analysis

NARCIS (Netherlands)

Nahar, S.N.; Schmets, A.J.M.; Scarpas, Athanasios

Trace elements and their concentrations play an important role in both chemical and physical properties of bitumen. Instrumental Neutron Activation Analysis (INAA) has been applied to determine the concentration of trace elements in bitumen. This method requires irradiation of the material with

Validation of computational methods for treatment planning of fast-neutron therapy using activation foil techniques

International Nuclear Information System (INIS)

Nigg, D.W.; Wemple, C.A.; Hartwell, J.K.; Harker, Y.D.; Venhuizen, J.R.; Risler, R.

1997-12-01

A closed-form direct method for unfolding neutron spectra from foil activation data is presented. The method is applied to measurements of the free-field neutron spectrum produced by the proton-cyclotron-based fast-neutron radiotherapy facility at the University of Washington (UW) School of Medicine. The results compare favorably with theoretical expectations based on an a-priori calculational model of the target and neutron beamline configuration of the UW facility

Neutron activation analysis of trace elements in foodstuffs

International Nuclear Information System (INIS)

Schelenz, R.; Bayat, I.; Fischer, E.

1976-05-01

For the determination of trace elements in foodstuffs with the aid of neutron activation analysis the separation of volatile radionuclides after digestion of the sample is of special interest for radiochemical processing. A distillation procedure was developed to give reproducable results, however optimal conditions were not found for all volatile radionuclides studied. The required selective separation of Br-82 from the distillate was best achieved by the application of an ion-exchange column-chromatography technique. The computer programs for the evaluation of complex gamma spectra have been developed further. The automatic peak search and peak area determination is based on a computer program using the correlation technique and carried out with a mini-computer coupled with a multi-channel gamma spectrometer. The results, which are presented in 3 earlier reports relating to this research program, reveal the advantages and disadvantages of the individual steps of the radiochemical separation scheme. Before neutron activation analysis can be introduced on a routine basis, some aspects of the radiochemical process remain to be tested; these studies will be published in a fourth and final report. (orig.) [de

Large Sample Neutron Activation Analysis of Heterogeneous Samples

International Nuclear Information System (INIS)

Stamatelatos, I.E.; Vasilopoulou, T.; Tzika, F.

2018-01-01

A Large Sample Neutron Activation Analysis (LSNAA) technique was developed for non-destructive analysis of heterogeneous bulk samples. The technique incorporated collimated scanning and combining experimental measurements and Monte Carlo simulations for the identification of inhomogeneities in large volume samples and the correction of their effect on the interpretation of gamma-spectrometry data. Corrections were applied for the effect of neutron self-shielding, gamma-ray attenuation, geometrical factor and heterogeneous activity distribution within the sample. A benchmark experiment was performed to investigate the effect of heterogeneity on the accuracy of LSNAA. Moreover, a ceramic vase was analyzed as a whole demonstrating the feasibility of the technique. The LSNAA results were compared against results obtained by INAA and a satisfactory agreement between the two methods was observed. This study showed that LSNAA is a technique capable to perform accurate non-destructive, multi-elemental compositional analysis of heterogeneous objects. It also revealed the great potential of the technique for the analysis of precious objects and artefacts that need to be preserved intact and cannot be damaged for sampling purposes. (author)

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

International Nuclear Information System (INIS)

Watterson, J.I.W.

1978-01-01

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

Ultra-micro determination of arsenic in biomaterials by neutron activation analysis

International Nuclear Information System (INIS)

Danbara, Hirosh; Suzuki, Nobuo

1989-01-01

10 - 100 ng levels of As in biomaterials (plasma, urine, hair and other animal tissues) were determined by destructive thermal neutron activation analysis. Materials were digested with HNO 3 - HClO 4 , reduced to H As then distilled by Gutzeit procedure. Removed H As by distration was accepted with filter paper contained appropriate reagent. This filter paper was irradiated with thermal neutron flux. The photopeaks of 76 As (559 and 657 Kev), 75 As(n,r) 76 As, were measured and compared with standard As peaks. Some of factors related to the determination such as reagent, condition of ditilation and activation were investigated. Almost satisfactory results were obtained

Neutron activation analysis of the rare earth elements in Nasu hot springs

International Nuclear Information System (INIS)

Ikeda, Nagao; Takahashi, Naruto.

1978-01-01

Eleven rare earth elements (lanthanum, cerium, neodymium, samarium, europium, gadolinium, terbium, holmium, thulium, ytterbium and lutetium) in hot spring waters and sinter deposits in the Nasu area were determined by the neutron activation method. The rare earth elements in hot spring water were preconcentrated in ferric hydroxide precipitate and neutron-irradiated. The rare earth elements were chemically separated into lighter and heavier groups and the activity of each group was measured with a Ge(Li) detector. Distribution of the rare earth elements between the hot spring water and the sinter deposit was also discussed. (auth.)

Code ACTIVE for calculation of the transmutation, induced activity and decay heat in neutron irradiation

International Nuclear Information System (INIS)

Ioki, Kimihiro; Harada, Yuhei; Asami, Naoto.

1976-03-01

The computer code ACTIVE has been prepared for calculation of the transmutation rate, induced activity and decay heat. Calculations are carried out with activation chain and spatial distribution of neutron energy spectrum. The spatial distribution of secondary gamma-ray source due to the unstable nuclides is also obtainable. Special attension is paid to the short life decays. (auth.)

Application of Fast Neutron Activity for Analysing Element Content on the Air Particulate

International Nuclear Information System (INIS)

Elin Nuraini; Ngasifudin; Sunardi; Elisabeth

2003-01-01

The research on application of fast neutron activation analysis for analysing element content on the air particulate has been done. The research about analysis of the particulate matters contained in non industrial traffic territory of Surakarta and full industrial traffic territory of Karanganyar, had been done using Fast Neutron Activation Analysis Method. Fast Neutron Activation Analysis method is one of the element analysis method which it's basic principle causes radioactivity appearance from the samples after being irradiated by neutron. The qualitative analysis method is based on the measuring of specific energy which was radiated by radioactive's nucleus and quantitative analysis method is based on the measuring of the intensity of each peak gamma energy. The qualitative analysis results showed, some element were identified i.e : 51 V ; 200 Pb, 27 Al and 52 Cr. The result showed that Pb level is 2.21 ± 0.09x10 -1 mg/m 3 in non industrial traffic territory of Surakarta and 2.78 ± 0.11x10 -1 mg/m 3 full industrial traffic territory of Karanganyar, this value greater than threshold value according 6.0x10 -2 mg/m 3 . (author)

Integral activation experiment of fusion reactor materials with d-Li neutrons up to 55 MeV

Energy Technology Data Exchange (ETDEWEB)

Maekawa, Fujio; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Moellendorff, Ulrich von [Forschungszentrum Karlsruhe, Karlsruhe (Germany); Wada, Masayuki [Business Automation Co., Ltd., Tokyo (Japan)

2000-03-01

An integral activation experiment of fusion reactor materials with a deuteron-lithium neutron source was performed. Since the maximum energy of neutrons produced was 55 MeV, the experiment with associated analysis was one of the first attempts for extending the energy range beyond 20 MeV. The following keywords represent the present study: d-Li neutrons, 55 MeV, dosimetry, SAND-II, spectrum adjustment, LA-150, MCNP, McDeLi, IFMIF, fusion reactor materials, integral activation experiment, low-activation, F82H, vanadium-alloy, IEAF, ALARA, and sequential charged particle reaction. (author)

A Brief overview of neutron activation analyses methodology and applications

International Nuclear Information System (INIS)

Ali, M.A.

2000-01-01

The primary objective of this talk is to present our new facility for Neutron Activation Analysis to the scientific and industrial societies and show its possibilities. Therefore my talk will handle the following main items: An overview of neutron activation analysis, The special interest of fast mono-energetic neutrons, The NAA method and its sensitivities, The Recent scientific and industrial applications using NAA, and o An illustrating example measured by using our facility is presented What is NAA? It is a sensitive analytical technique useful for performing both qualitative and quantitative multi-element analyses in samples. Worldwide application of NAA is so widespread; it is estimated that approximately several 10,000 samples undergo analysis each year from almost every conceivable field of scientific or technical interest. Why NAA? For many elements and applications, NAA: Offers sensitivities that are sometimes superior to those attainable by other methods, on the order of nano-gram level, It is accurate and reliable, NAA is generally recognized as the r eferee method o f choice when new procedures are being developed or when other methods yield results that do not agree. However, the activation analysis at En=14 MeV is limited by a few factors: Low value of flux, low cross-sections of threshold reactions, o Short irradiation time due to finite target life, Interfering reactions and gamma ray spectral interference

L'analyse par activation de neutrons de réacteur

Science.gov (United States)

Meyer, G.

2003-02-01

Quand les neutrons traversent la matière, certains sont transmis sans interaction, les autres interagissent avec le milieu traversé par diffusion et par absorption. Ce phénomène d'absorption est utilisé pour se protéger des neutrons, mais aussi pour les détecter; il peut également être utilisé pour identifier les noyaux “absorbants" et ainsi analyser le milieu traversé. En effet par différentes réactions nucléaires (n,γ), (n,p), (n,α), (n,fission), on obtient des noyaux résiduels qui sont souvent radioactifs; on dit que l'échantillon est “activé". Si l'on connaît le rendement d'activation et donc le pourcentage de noyaux ainsi “transmutés", les mesures de radioactivité induite vont permettre de déterminer la composition de l'échantillon irradié. Cette méthode dite d'analyse par activation neutronique est pratiquée depuis la découverte du neutron. Elle a permis grâce à sa sélectivité et à sa sensibilité d'avoir accès au domaine des traces et des ultra-traces dans des champs d'application très divers comme la métallurgie, l'archéologie, la biologie, la géochimie etc...

Mercury mass measurement in fluorescent lamps via neutron activation analysis

Science.gov (United States)

Viererbl, L.; Vinš, M.; Lahodová, Z.; Fuksa, A.; Kučera, J.; Koleška, M.; Voljanskij, A.

2015-11-01

Mercury is an essential component of fluorescent lamps. Not all fluorescent lamps are recycled, resulting in contamination of the environment with toxic mercury, making measurement of the mercury mass used in fluorescent lamps important. Mercury mass measurement of lamps via instrumental neutron activation analysis (NAA) was tested under various conditions in the LVR-15 research reactor. Fluorescent lamps were irradiated in different positions in vertical irradiation channels and a horizontal channel in neutron fields with total fluence rates from 3×108 cm-2 s-1 to 1014 cm-2 s-1. The 202Hg(n,γ)203Hg nuclear reaction was used for mercury mass evaluation. Activities of 203Hg and others induced radionuclides were measured via gamma spectrometry with an HPGe detector at various times after irradiation. Standards containing an Hg2Cl2 compound were used to determine mercury mass. Problems arise from the presence of elements with a large effective cross section in luminescent material (europium, antimony and gadolinium) and glass (boron). The paper describes optimization of the NAA procedure in the LVR-15 research reactor with particular attention to influence of neutron self-absorption in fluorescent lamps.

High-fidelity MCNP modeling of a D-T neutron generator for active interrogation of special nuclear material

International Nuclear Information System (INIS)

Katalenich, Jeff; Flaska, Marek; Pozzi, Sara A.; Hartman, Michael R.

2011-01-01

Fast and robust methods for interrogation of special nuclear material (SNM) are of interest to many agencies and institutions in the United States. It is well known that passive interrogation methods are typically sufficient for plutonium identification because of a relatively high neutron production rate from 240 Pu . On the other hand, identification of shielded uranium requires active methods using neutron or photon sources . Deuterium-deuterium (2.45 MeV) and deuterium-tritium (14.1 MeV) neutron-generator sources have been previously tested and proven to be relatively reliable instruments for active interrogation of nuclear materials . In addition, the newest generators of this type are small enough for applications requiring portable interrogation systems. Active interrogation techniques using high-energy neutrons are being investigated as a method to detect hidden SNM in shielded containers . Due to the thickness of some containers, penetrating radiation such as high-energy neutrons can provide a potential means of probing shielded SNM. In an effort to develop the capability to assess the signal seen from various forms of shielded nuclear materials, University of Michigan Neutron Science Laboratory's D-T neutron generator and its shielding were accurately modeled in MCNP. The generator, while operating at nominal power, produces approximately 1x10 10 neutrons/s, a source intensity which requires a large amount of shielding to minimize the dose rates around the generator. For this reason, the existing shielding completely encompasses the generator and does not include beam ports. Therefore, several MCNP simulations were performed to estimate the yield of uncollided 14.1-MeV neutrons from the generator for active interrogation experiments. Beam port diameters of 5, 10, 15, 20, and 25 cm were modeled to assess the resulting neutron fluxes. The neutron flux outside the beam ports was estimated to be approximately 2x10 4 n/cm 2 s.

Neutron activation analysis: recent developments and applications

International Nuclear Information System (INIS)

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

2012-01-01

Neutron activation analysis (NAA) is a powerful isotope specific nuclear analytical technique for simultaneous determination of major to trace elemental concentrations in diverse matrices. NAA is associated with high analytical sensitivities and low detection limits (ppm to ppb) due to utilization of high neutron flux from research reactors and high efficiency high resolution gamma ray spectrometry. Elemental concentrations are determined either by conventional NAA using relative method or by single comparator method of NAA (k 0 -NAA). Since 1994, Radiochemistry Division is actively engaged in developments and applications of k 0 -based NAA and Prompt Gamma ray NAA (PGNAA) methods for compositional characterization of materials, in addition to conventional instrumental NAA (INAA) and chemical NAA (CNAA) methods for total as well as speciation studies. The article briefly summarizes developments of k 0 based method of NAA using an external single comparator (k 0 -NAA) and an internal monostandard (lM-NAA) and PGNAA and their applications to small as well as large size samples. The article also briefly highlights the application of INAA and chemical NAA (CNAA) for speciation studies of arsenic and iodine in environmental and food samples respectively and bioaccesibility of selenium in food samples and trace elements wheatgrass samples

Neutron activation analysis of alternative waste forms at the Savannah River Laboratory

International Nuclear Information System (INIS)

Johns, R.A.

1981-01-01

A remotely controlled system for neutron activation of candidate high-level waste (HLW) isolation forms was built by the Savannah River Laboratory at a Savannah River Plant reactor. With this system, samples can be irradiated for up to 24 hours and transferred through pneumatic tubing to a shielded repository unitl their activity is low enough for them to be handled in a radiobench. The principal use of the system is to support the Alternative Waste Forms Leach Testing (AWFLT) Program in which the comparative leachability of the various waste forms will be determined. The experimental method used in this work is based on neutron activation analysis techniques. Neutron irradiation of the solid waste form containing simulated HLW sludge activates elements in the sample. After suitable leaching of the solid matrix in standard solutions, the leachate and solid are assayed for gamma-emitting nuclides. From these measurements, the fraction of a specific element leached can be determined al half-lives with experimental ones, over a range of 24 orders of magnitude was obtained. This is a strong argument that the alpha decay could be considered a fission process with very high mass asymmetry and charge density asymmetry

Corrections in the gold foil activation method for determination of neutron beam density

DEFF Research Database (Denmark)

Als-Nielsen, Jens Aage

1967-01-01

A finite foil thickness and deviation in the cross section from the 1ν law imply corrections in the determination of neutron beam densities by means of foil activation. These corrections, which depend on the neutron velocity distribution, have been examined in general and are given in a specific...

Neutron activation analysis of atmospheric aerosol

International Nuclear Information System (INIS)

Obrusnik, I.

1986-01-01

Neutron activation analysis (NAA) is a modern analytical method well suited for the analysis of atmospheric aerosols. Particular steps of the NAA procedure and especially different types of aerosol sampling and sample preparation for analysis are discussed in detail. Several possible NAA techniques are described and the advantages of a purely instrumental technique with short and long irradiation are pointed out. Important performance characteristics of the NAA method such as precision, accuracy, sensitivity and detection limits are also discussed. Different applications of NAA in environmental studies are reviewed. (author)

Neutron activation measurements in research reactor concrete shield

International Nuclear Information System (INIS)

Zagar, T.; Ravnik, M.; Bozic, M.

2001-01-01

The results of activation measurement inside TRIGA research reactor concrete shielding are given. Samples made of ordinary and barytes concrete together with gold and nickel foils were irradiated in the reactor body. Long-lived neutron-induced gamma-ray-emitting radioactive nuclides in the samples were measured with HPGe detector. The most active longlived radioactive nuclides in ordinary concrete samples were found to be 60 Co and 152 Eu and in barytes concrete samples 60 Co, 152 Eu and 133 Ba. Measured activity density of all nuclides was found to decrease almost linearly with depth in logarithmic scale.(author)

Neutron activation analysis of the rare earth elements in rocks from the earth's upper mantle and deep crust

International Nuclear Information System (INIS)

Stosch, H.-G.; Koetz, J.; Herpers, U.

1986-01-01

Three techniques for analyzing rare earth elements (REE) in geological materials are described, i.e. instrumental neutron activation analysis (INAA), neutron activation analysis with pre-irradiation chemical REE separation (PCS-NAA) and radiochemical neutron activation analysis (RNAA). The knowledge of REE concentrationd in eclogites, peridotites and minerals from the earth's lower crust and upper mantle is very useful in constraining their petrogenetic history. (author)

Obsidian sources characterized by neutron-activation analysis.

Science.gov (United States)

Gordus, A A; Wright, G A; Griffin, J B

1968-07-26

Concentrations of elements such as manganese, scandium, lanthanum, rubidium, samarium, barium, and zirconium in obsidian samples from different flows show ranges of 1000 percent or more, whereas the variation in element content in obsidian samples from a single flow appears to be less than 40 percent. Neutron-activation analysis of these elements, as well as of sodium and iron, provides a means of identifying the geologic source of an archeological artifact of obsidian.

Reactor neutron activation analysis of industrial materials

International Nuclear Information System (INIS)

Niese, S.

1983-01-01

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

Radiography apparatus using gamma rays emitted by water activated by fusion neutrons

Science.gov (United States)

Smith, Donald L.; Ikeda, Yujiro; Uno, Yoshitomo

1996-01-01

Radiography apparatus includes an arrangement for circulating pure water continuously between a location adjacent a source of energetic neutrons, such as a tritium target irradiated by a deuteron beam, and a remote location where radiographic analysis is conducted. Oxygen in the pure water is activated via the .sup.16 O(n,p).sup.16 N reaction using .sup.14 -MeV neutrons produced at the neutron source via the .sup.3 H(d,n).sup.4 He reaction. Essentially monoenergetic gamma rays at 6.129 (predominantly) and 7.115 MeV are produced by the 7.13-second .sup.16 N decay for use in radiographic analysis. The gamma rays have substantial penetrating power and are useful in determining the thickness of materials and elemental compositions, particularly for metals and high-atomic number materials. The characteristic decay half life of 7.13 seconds of the activated oxygen is sufficient to permit gamma ray generation at a remote location where the activated water is transported, while not presenting a chemical or radioactivity hazard because the radioactivity falls to negligible levels after 1-2 minutes.

Russia: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

International Nuclear Information System (INIS)

Kozlenko, Denis

2012-01-01

The development of neutron imaging techniques as a tool for non-destructive analysis of the internal structure, defects and processes in industrial products, functional materials, objects of cultural heritage attracts considerable attention at the present time. The dedicated instruments are available at the many neutron sources. The IBR-2M high flux pulsed reactor is one of the most powerful pulsed neutron sources in the world with the average power 2 MW, power per neutron pulse 1850 MW and neutron flux in pulse of 5·10 15 n/cm 2 /s. During the period December 2006 – December 2010 the reactor was on modernization for replacement of the reactor vessel and fuel elements. During 2011, the successful physical and power start-up of IBR-2M were performed. Now reactor is operational and can be used for research and development activities using neutron scattering techniques in next 25 years prospective. However, no instruments dedicated for neutron imaging is installed at IBR-2M so far. Moreover, in Russian Federation there is no dedicated neutron imaging facility for cultural heritage research at the moment

Thermal neutron detection by activation of CaSO4:Dy + KBr thermoluminescent phosphors

International Nuclear Information System (INIS)

Gordon, A.M.P.L.; Muccillo, R.

1979-01-01

Thermoluminescence (TL) studies to detect thermal neutrons were performed in cold-pressed CaSO 4 :0,1%Dy + KBr samples. The detection is based on the self-irradiation of the CaSO 4 :Dy TL phosphor by the Br isotopes activated by exposure to a mixed neutron-gamma field. (Author) [pt

Techniques of in vivo neutron activation analysis

International Nuclear Information System (INIS)

Chettle, D.R.; Fremlin, J.H.

1984-01-01

This review is dealt with under the following headings, intended to reflect the different factors affecting the measurement sensitivity, starting with the choice of neutron source and proceeding, through the reaction characteristics, to the detection system, the questions of dosimetry and ethical constraints being also discussed: 1) neutron sources, slowing down and interaction processes, energy spectrum and flux uniformity, timing 2) neutron reactions used for in vivo analyses 3) detectors, choice, geometrical considerations and detector shielding 4) data collection and processing 5) interpretation, major elements, absolute or sequential measurements, relationship to other parameters 6) dosimetry, framework for dose levels, biological effects of neutron interactions, neutron doses in practice 7) implications for measurement of calcium, nitrogen and cadmium. (U.K.)

The importance of using the mixed neutron flux in activation analysis of D-3He fueled reactors

International Nuclear Information System (INIS)

Khater, H.Y.; Sawan, M.E.

1992-01-01

This paper reports on the D-D and D-T secondary reactions in D- 3 He reactors which provide the neutron source term for most of the radioactivity produced in the structure of the reactor. radionuclides are produced as a result of neutron interactions with their parent nuclides. The amount of activity produced by any radionuclide depends on the number of its parent atoms present at any given time. One approach to account for the activity induced by both neutron sources in any activation analysis is to add their individual contributions. Performing two separate calculations for the D-D and D-T neutron flux components and adding their contributions yields conservative results due to underestimating the destruction of the parent atoms. The overestimation is more pronounced for short and intermediate lived nuclides, long operation time, large neutron flux and large destruction cross section for the parent atoms. In the steel first wall of a typical d- 3 He reactor, adding the individual contributions of the tow neutron sources results in overestimating the activities produced by most of the radioactive isotopes of Ag, Lu, Ta, W and Re. After 30 years of reactor operation, the activity of 187 W, which is a major source of safety concern in case of an accident, is more than an order of magnitude higher than its value if the mixed neutron flux is used. The activity of 188 Re, which is an important source of offsite does in case of accidental release, is overestimated by more than a factor of two

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

Energy Technology Data Exchange (ETDEWEB)

Brune, D; Jirlow, J

1963-12-15

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

Instrumental Neutron Activation Analysis and Multivariate Statistics for Pottery Provenance

Science.gov (United States)

Glascock, M. D.; Neff, H.; Vaughn, K. J.

2004-06-01

The application of instrumental neutron activation analysis and multivariate statistics to archaeological studies of ceramics and clays is described. A small pottery data set from the Nasca culture in southern Peru is presented for illustration.

Instrumental Neutron Activation Analysis and Multivariate Statistics for Pottery Provenance

International Nuclear Information System (INIS)

Glascock, M. D.; Neff, H.; Vaughn, K. J.

2004-01-01

The application of instrumental neutron activation analysis and multivariate statistics to archaeological studies of ceramics and clays is described. A small pottery data set from the Nasca culture in southern Peru is presented for illustration.

Instrumental Neutron Activation Analysis and Multivariate Statistics for Pottery Provenance

Energy Technology Data Exchange (ETDEWEB)

Glascock, M. D.; Neff, H. [University of Missouri, Research Reactor Center (United States); Vaughn, K. J. [Pacific Lutheran University, Department of Anthropology (United States)