Initial Gamma Spectrometry Examination of the AGR-3/4 Irradiation

Energy Technology Data Exchange (ETDEWEB)

Harp, Jason M.; Demkowicz, Paul A.; Stempien, John D.

2016-11-01

The initial results from gamma spectrometry examination of the different components from the combined third and fourth US Advanced Gas Reactor Fuel Development TRISO-coated particle fuel irradiation tests (AGR-3/4) have been analyzed. This experiment was designed to provide information about in-pile fission product migration. In each of the 12 capsules, a single stack of four compacts with designed-to-fail particles surrounded by two graphitic diffusion rings (inner and outer) and a graphite sink were irradiated in the Idaho National Laboratory’s Advanced Test Reactor. Gamma spectrometry has been used to evaluate the gamma-emitting fission product inventory of compacts from the irradiation and evaluate the burnup of these compacts based on the activity of the radioactive cesium isotopes (Cs-134 and Cs-137) in the compacts. Burnup from gamma spectrometry compares well with predicted burnup from simulations. Additionally, inner and outer rings were also examined by gamma spectrometry both to evaluate the fission product inventory and the distribution of gamma-emitting fission products within the rings using gamma emission computed tomography. The cesium inventory of the scanned rings compares acceptably well with the expected inventory from fission product transport modeling. The inventory of the graphite fission product sinks is also being evaluated by gamma spectrometry.

Janus probe, a detection system for high energy reactor gamma-ray spectrometry

International Nuclear Information System (INIS)

Gold, R.; Kaiser, B.J.

1980-03-01

In reactor environments, gamma-ray spectra are continuous and the absolute magnitude as well as the general shape of the gamma continuum are of paramount importance. Consequently, conventional methods of gamma-ray detection are not suitable for in-core gamma-ray spectrometry. To meet these specific needs, a method of continuous gamma-ray spectrometry, namely Compton Recoil Gamma-Ray Spectrometry, was developed for in-situ observations of reactor environments. A new gamma-ray detection system has been developed which extends the applicability of Compton Recoil Gamma-Ray Spectrometry up to roughly 7 MeV. This detection system is comprised of two separate Si(Li) detectors placed face-to-face. Hence this new detection system is called the Janus probe. Also shown is the block diagram of pulse processing instrumentation for the Janus probe. This new gamma probe not only extends the upper energy limit of in-core gamma-ray spectrometry, but in addition possesses other fundamental advantages

Metrological characterization of the numerical system Adonis for gamma spectrometry; Caracterisation metrologique du systeme de spectrometrie gamma numerique Adonis

Energy Technology Data Exchange (ETDEWEB)

Plagnard, J.; Morel, J.; Tran Tuan, A

2005-07-01

In gamma spectrometry, new acquisition systems based on digital processing of the signals are now available on the market. In order to determine their performances at high count rates, The CEA-LNHB (Commissariat a l'Energie Atomique - Laboratoire National Henri Becquerel) has tested several of these equipments.. These tests have clearly shown that the performances announced by the manufacturers were generally not met. At this point, it was interesting to include in these tests, the system ADONIS (Atelier de Developpement Numerique pour l'Instrumentation en Spectrometrie), which is the new gamma spectrometry system, developed by the CEA-SIAR (Service d'Instrumentation et d'Application des Rayonnements). (authors)

Rat beta-LPH, gamma-LPH and beta-endorphin biosynthesized by isolated cells of pars intermedia and pars distalis

International Nuclear Information System (INIS)

Gianoulakis, C.; Seidah, N.G.; Routhier, R.; Chretien, M.

1980-01-01

Rats pars intermedia cells were incubated for 3 h with the following amino-acids: a) 35 S-methionine and 3 H-phenylalamine; b) 3 H-valine; and c) 3 H-valine and 3 H-lysine. Radioactive gamma-lipotropin, beta-lipotropin and beta-endorphin were purified on carboxy- methyl-cellulose and characterized by polyacrylamide disc gel electrophoresis af pH 4.5, molecular weight estimation and microsequencing. Rat gamma-lipotropin was shown to differ slightly from ovine gamma-lipotropin in its NH 2 -terminal amino acid sequence, in containing no methionine and having phenylalanine at position 6, valine at positions 13 and 27, and lysine at position 20. The same variations were observed in the sequence of rat beta-lipotropin, while rat beta-endorphin was shown to be identical to the ovine beta-endorphin. Following a 3-h pulse of rat pars distalis, the cells were extracted with care to avoid beta-lipotropin degradation by proteolytic enzymes. A peptide was purified and identified to be rat beta-endorphin, thus demonstrating that beta-endorphin is biosynthesized in pars distalis and is not an extraction artifact. (author)

Correcting the effects of the matrix using capture gamma-ray spectrometry: Application to measurement by Active Neutron Interrogation; Correction des effets de matrice par spectrometrie des rayonnements gamma de capture: Application a la mesure par Interrogation Neutronique Active (I.N.A.)

Energy Technology Data Exchange (ETDEWEB)

Baudry, G.

2003-11-15

In the field of the measurement of low masses of fissile material ({sup 235}U, {sup 239}Pu, {sup 241}Pu) in radioactive waste drums, the Active Neutron Interrogation is a non-destructive method achieving good results. It does however remain reliant upon uncertainties related to the matrix effects on interrogation and fission neutrons. The aim of this thesis is to develop a correction method able to take into account these matrix effects by quantifying the amount of absorbent materials (chlorine and hydrogen) in a 118- liter homogeneous matrix. The main idea is to use the gamma-ray spectrometry of gamma emitted by neutron captures to identify and quantify the composition of the matrix. An indicator from its chlorine content is then deduced in order to choose the calibration coefficient which best represents the real composition of the matrix. This document firstly presents the needs of control and characterization of radioactive objects, and the means used in the field of nuclear measurement. Emphases is put in particular on the Active Neutron Interrogation method. The matrices of interest are those made of light technological waste (density {<=} 0,4 g/cm{sup 3}) containing hydrogenated and chlorinated materials. The advantages of gamma-rays emitted by neutron captures for the determination of a chlorine content indicator of the matrices and the principles of the correction method are then explained. Measurements have been firstly realized with an existing Neutron Interrogation device (PROMETHEE 6). Such measurements have proven its inadequacy: no signal from the matrix hydrogen was detected, due to an intense signal from the polyethylene contained in some cell elements. Moreover, the matrix chlorine content appeared difficult to be measured. A new and specific device, named REGAIN and dedicated to active gamma-rays spectrometry, was defined with the Monte-Carlo N-Particle (MCNP) code. The experiments conducted with this new device made it possible to detect the

An automatic sample changer for gamma spectrometry

International Nuclear Information System (INIS)

Andrews, D.J.

1984-01-01

An automatic sample changer for gamma spectrometry is described which is designed for large-volume, low radioactivity environmental samples of various sizes up to maximum dimensions 100 mm diameter x 60 mm high. The sample changer is suitable for use with most existing gamma spectrometry systems which utilize GeLi or NaI detectors in vertical mode, in conjunction with a pulse height analyzer having auto-cycle and suitable data output facilities; it is linked to a Nuclear Data ND 6620 computer-based analysis system. (U.K.)

Experience gained in gamma spectroscopy; Experience acquise dans la spectrometrie gamma

Energy Technology Data Exchange (ETDEWEB)

Jeanmaire, L [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

There are two types of method which make it possible to estimate the internal contamination of individuals. On the one hand these are the indirect techniques based on measurements of the excreted products, on the other there are the direct techniques in which attempts are made to measure directly the radio-activity existing in the organism. We propose to give a few of the results obtained by the direct method using equipment built by the Commissariat a l'Energie Atomique. The apparatus consists of a {gamma} spectrometer. It includes: 1) A crystal of sodium iodide 20 cm in diameter and 10 cm high. The large size of this crystal ensures a good sensitivity and makes it possible to carry out rapid measurements. 2) A 25 channel type SAE 25 selector which classifies the pulses according to their amplitude. It is therefore possible to distinguish between {gamma} rays of varying energy. 3) A comparatively very light radiation protection, consisting of only 5 cm thickness of lead which diminishes the ambient {gamma} ray intensity to a sufficient level for the majority of the measurements. A certain collimation is thus obtained which makes it possible to localise the source approximately and to reduce the undesirable effects of external contamination. (author) [French] Deux types de methodes permettent d'apprecier la contamination interne d'un individu. D'une part, les techniques indirectes basees sur la mesure des produits excretes, d'autre part, les techniques directes au moyen desquelles on essaie de mesurer directement la radioactivite existant dans l'organisme. Nous nous proposons d'indiquer quelques resultats obtenus par la methode directe, au moyen d'ensembles realises par le Commissariat a l'Energie Atomique. L'appareillage est un spectrometre {gamma}. II comprend: 1) Un cristal d'iodure de sodium de 20 cm de diametre et 10 cm de hauteur. La grande taille de ce cristal assure une bonne sensibilite et permet d'effectuer des mesures rapides. 2) Un selecteur a 25 canaux

Multidimensional Gamma-Ray Spectrometry and its Use in Biology; La Spectrometry Gamma Multidimensionnelle et son Application en Biologie; Mnogomernaya spektrometriya gamma-luchej i ee ispol'zovanie v biologii; La Espectrometria Gamma Multidimensional y su Empleo en Biologia

Energy Technology Data Exchange (ETDEWEB)

Nielsen, J. M.; Kornberg, H. A. [Battelle Memorial Institute, Pacific Northwest Laboratory, Richland, WA (United States)

1965-10-15

could be applied to studies where tracers are added and would be especially useful for the simultaneous measurement of absorption, deposition, and turnover in the animal body of several suitably labelled compounds. When used with neutron activation analysis measurements of a large group of elements may be made in tissues and blood at the parts per billion level. (author) [French] La spectrometrie gamma multidimensionnelle constitue une nouvelle methode de mesure des radionuclides qui a trouve des applications particulieres en biologie. Cette methode instrumentale permet d'identifier et de mesurer directement et separement, sans traitement chimique prealable, les emetteurs gamma de melanges complexes de radionuclides se trouvant dans diverses matrices echantillons. Le detecteur presente les caracteristiques suivantes: grande sensibilite, assuree par deux detecteurs 9 Nal(Tl) de 15 cm de diametre et 10 cm d'epaisseur; grande selectivite obtenue grace a des methodes de comptage par coiencidence qui separent les spectres des rayons gamma en utilisant les caracteristiques de desintegration gamma de chaque radionuclide; bruit de fond extremement faible et interference Compton reduite par suite de la presence d'un detecteur annulaire en anticoiencidence (cristal de NaI(Tl) de 29 cm d'epaisseur, ayant un diametre interieur de 16 cm). Un analyseur multidimensionnel a 4096 canaux analyse les deux rayons gamma en coiencidence en fonction de leur energie et les enregistre dans le plan de la memoire a 64 x 64 canaux, alors que les evenements survenant en anticoiencidence sont enregistres seulement dans les axes de la memoire. Il en resulte une diminution sensible de plusieurs ordres de grandeur du bruit de fond et de l'interference Compton, etune forte augmentation de la selectivite. La mesure directe par spectrometrie gamma de radionuclides a l'etat de traces dans des echantillons biologiques a ete genee par la presence de quantites relativement importantes de {sup 40}K naturel a

Guidelines for radioelement mapping using gamma ray spectrometry data

International Nuclear Information System (INIS)

2003-07-01

The purpose of the report is to provide an up-to-date review on the use of gamma ray spectrometry for radioelement mapping and, where appropriate, provide guidelines on the correct application of the method. It is a useful training guide for those new to the method. It gives a broad coverage of all aspects of the gamma ray method and provides a comprehensive list of references. The report gives an overview of the theoretical background to radioactivity and the gamma ray spectrometric method followed by a review of the application of the method to mapping the radiation environment. A brief outline is presented of the principles of radioactivity, the interaction of gamma rays with matter, instrumentation applied to the measurement of gamma rays, and the quantities and units in contemporary use in gamma ray spectrometry. This is followed by a review of the fundamentals of gamma ray spectrometry, and its application to ground and airborne mapping. Covered are also all aspects of the calibration and data processing procedures required for estimating the ground concentrations of the radioelements. The procedures required for the recovery of older survey data are also presented as well as an overview of data presentation and integration for mapping applications

Detector calibration for in-situ gamma ray spectrometry

CERN Document Server

Balea, G

2002-01-01

The power in the technique of in-situ spectrometry lies in the fact that a detector placed on ground measures gamma radiation from sources situated over an area of several hundred square meters. The 'field of view' for the detector would be larger for high energy radiation sources and for sources closer to the soil surface. In contrast, a soil sample would represent an area of a few tens of hundreds of square centimeters. In practice, an effective characterization of a site would involve in-situ gamma ray spectrometry in conjunction with soil sampling. As part of an overall program, in-situ gamma ray spectrometry provides a means to assess the degree of contamination in areas during the course of operations in the field, thus guiding the investigator on where to collect samples. It can also substantially reduce the number of samples need to be collected and subsequently analyzed. (author)

Aircraft gamma-ray spectrometry in snow-water equivalent measurement

Energy Technology Data Exchange (ETDEWEB)

Kuittinen, R; Vironmaeki, J

1979-01-01

During the winter periods of 1976 to 1977 and 1977 to 1978, the Hydrological Office at the National Boards of Waters and the Geological Survey of Finland carried out a joint study to evaluate usefulness of gamma-ray spectrometry in snowwater equivalent measurement. A multichannel gamma-ray spectrometry was fitted out in a DC-3 aircraft. Fourteen snow courses were operated using gravimetric method and gamma-ray method. The snow courses were located in southern Finland in forest, swamp and agricultural land. The results show that the gamma ray method can be considered suitable for use in Finnish conditions and the accuracy of the gamma-ray method is almost of the same magnitude of the accuracy of the gravimetric method.

Gamma-emissions of some meteorites and terrestrial rocks. Evaluation of lunar soil radioactivity; Emissions gamma de quelques meteorites et roches terrestres. Evaluation de la radioactivite du sol lunaire

Energy Technology Data Exchange (ETDEWEB)

Nordemann, D. [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

1966-07-01

The gamma-emissions of some terrestrial rocks and of the following meteorites: Bogou, Eagle-Station, Granes, and Dosso were studied by quantitative low background gamma spectrometry. These measurements and their interpretation lead to the evaluation of the possible gamma-emissions of several models of lunar soils. (author) [French] Les emissions gamma des meteorites Bogou, Eagle-Station, Granes et Dosso et de quelques roches terrestres ont ete etudiees par spectrometrie gamma quantitative a faible mouvement propre. Ces mesures et leur interpretation permettent d'evaluer les principales contributions des emissions gamma du sol lunaire pour des modeles de compositions possibles variees. (auteur)

Gamma-emissions of some meteorites and terrestrial rocks. Evaluation of lunar soil radioactivity; Emissions gamma de quelques meteorites et roches terrestres. Evaluation de la radioactivite du sol lunaire

Energy Technology Data Exchange (ETDEWEB)

Nordemann, D [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

1966-07-01

The gamma-emissions of some terrestrial rocks and of the following meteorites: Bogou, Eagle-Station, Granes, and Dosso were studied by quantitative low background gamma spectrometry. These measurements and their interpretation lead to the evaluation of the possible gamma-emissions of several models of lunar soils. (author) [French] Les emissions gamma des meteorites Bogou, Eagle-Station, Granes et Dosso et de quelques roches terrestres ont ete etudiees par spectrometrie gamma quantitative a faible mouvement propre. Ces mesures et leur interpretation permettent d'evaluer les principales contributions des emissions gamma du sol lunaire pour des modeles de compositions possibles variees. (auteur)

Processing of data issued from a {gamma} spectrometer; Traitement des informations issues d'un spectrometre {gamma}

Energy Technology Data Exchange (ETDEWEB)

Boulanger, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-03-01

The purpose of the following report is the study of computation method applied to analysis by gamma spectrometry. We first study quantitative analysis by the least-squares method, improved by a gain-shift correction. Then the single full-energy peaks and the resolution of complex peaks are dealt with. In both cases, the calculation principle, then the systematic tests achieved in order to-prove their validity and determine their application ranges are described and finally some experimental results appropriate to illustrate their possibilities are presented. (author) [French] Le present rapport a pour objet l'etude de methodes de calcul applicables a l'analyse par spectrometrie gamma. On etudie d'abord l'analyse quantitative par la methode des moindres carres, completee par une correction de derive du gain. Puis on examine les pics d'absorption totale simples et la resolution des pics complexes. Dans les deux cas, on expose le principe des calculs et les essais systematiques effectues pour eprouver leur validite et definir leurs domaines d'application, ainsi que quelques resultats experimentaux propres a illustrer leurs possibilites.

Measurement of radioactive isotopes by {gamma} and x rays spectrometry with INa crystals. application to radiochemistry of some fission and activation products; Mesures d'isotopes radioactifs par spectrometrie {gamma} et x a l'aide de cristaux INa. application a la radiochimie de certains produits de fission et d'activation

Energy Technology Data Exchange (ETDEWEB)

Simonet, P; Boile, G; Simonet, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

The measurement of an number of atoms N may be obtained by detection of one {gamma} ray emitted if its branching ratio K{sub E} is known (number of E energy {gamma} transitions/number of disintegrations). N = A/{lambda} N{sub {gamma}}{sub E} / (K{sub E} * {lambda}) This measurement is effectuated in well-defined geometry, {gamma} rays emitted by the source are detected by a calibrated NaI crystal which is connected to a photomultiplier delivering electric impulses analysed by a multichannel analyser. Crystals are chosen according to energy, intensity of measured rays and of background. Calibration is established with standard sources or by total absolute efficiency of a definite crystal. Half-life, energy of measured photopeak branching ratio have been determined for these isotopes: Fission products: {sup 95}Zr, {sup 95}Nb, {sup 99}Mo, {sup 103}Ru, {sup 106}Ru, {sup 111}Ag, {sup 115}Cd, {sup 115m}Cd, {sup 132}Te, {sup 129m}Te, {sup 134}Cs, {sup 136}Cs, {sup 137}Cs, {sup 140}Ba, {sup 140}La. Rare earth elements: {sup 91}Y, {sup 141}Ce, {sup 144}Ce, {sup 147}Nd, {sup 156}Eu. Products from reactions (n, {gamma}) (n, 2n): 1{sup 10}Ag, {sup 124}Sb, {sup 239}Np, {sup 237}U, {sup 241}Am. (authors) [French] La mesure du nombre d'atomes N d'un isotope peut s'effectuer sur un rayonnement {gamma} si l'on connait le rapport d'embranchement K{sub E} (nombre de rayonnements {gamma} d'energie E/nombre de desintegrations). N = A/{lambda} N{sub {gamma}}{sub E} / (K{sub E} * {lambda}) La mesure s'effectue en geometrie definie; les rayonnements {gamma} emis par la source sous mylar sont detectes par un cristal INa etalonne en fonction de l'energie, lequel est relie a un photomultiplicateur delivrant des impulsions electriques qui seront analysees par un selecteur multicanaux. La connaissance de la distribution theorique (effet photoelectrique, compton, paires, retrodiffusion, echappement... ) permet de determiner qualitativement si les elements sont purs, et de faire une mesure sur

On response operator in semiconductor gamma ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Krnac, S [Slovak Technical Univ., Bratislava (Slovakia); Povinec, P [International Atomic Energy Agency, Monaco (Monaco). MEL; Ragan, R [Inst. of Preventive and Clinical Medicine, Bratislava (Slovakia)

1996-12-31

Some results of the scaling confirmation factor analysis (SCFA) application in semiconductor gamma-ray spectrometry presented in this contribution points out to a new ground for evaluation the gamma-ray spectra. This whole-spectrum processing approach considerably increases detection sensitivity, especially, if significant interferences being present in the measured spectrum. Precision of the SCFA method is determined by choice of a sufficient number of suitable calibration gamma-ray sources in the energy region of interest, by setting up an acceptable latent hypothesis and by chosen experimental quantification of spectra. The SCFA method is very advantageous to use, for instance, in ultra low-level gamma-spectrometry where counting rates in full energy peaks are extremely low as compared with background interferences. It enables to increase of the sensitivity by the 5-10 times in comparison with the traditional full energy peak net area method (J.K.). 1 fig., 2 tabs., 6 refs.

On response operator in semiconductor gamma ray spectrometry

International Nuclear Information System (INIS)

Krnac, S.; Povinec, P.

1995-01-01

Some results of the scaling confirmation factor analysis (SCFA) application in semiconductor gamma-ray spectrometry presented in this contribution points out to a new ground for evaluation the gamma-ray spectra. This whole-spectrum processing approach considerably increases detection sensitivity, especially, if significant interferences being present in the measured spectrum. Precision of the SCFA method is determined by choice of a sufficient number of suitable calibration gamma-ray sources in the energy region of interest, by setting up an acceptable latent hypothesis and by chosen experimental quantification of spectra. The SCFA method is very advantageous to use, for instance, in ultra low-level gamma-spectrometry where counting rates in full energy peaks are extremely low as compared with background interferences. It enables to increase of the sensitivity by the 5-10 times in comparison with the traditional full energy peak net area method (J.K.). 1 fig., 2 tabs., 6 refs

Measurements of uranium enrichment by four techniques of gamma-ray spectrometry

International Nuclear Information System (INIS)

Tojo, Takao

1983-12-01

Measurements of uranium enrichment with the uses of the LMRI (France) UO 2 standards have been made by four techniques of gamma-ray spectrometry, in order to examine measurement characteristics of each technique. The following results were obtained by the three techniques based on the direct determination of the peak area of the 186-keV gamma-rays from 235 U, when the standard sample of 6.297 a/o was used for measuring enrichments ranging from 1.4 a/o to 9.6 a/o ; (i) In a LEPS HP Ge gamma-ray spectrometry, standard deviation of the measured enrichments from the certified ones was 1.4 %, (ii) in a Ge(Li) gamma-ray spectrometry, the standard deviation was 2.0 %, (iii) in a NaI(Tl) gamma-ray spectrometry, the standard deviation was 1.2 %. In the fourth technique, the method of multiple single-channel analyzers, enrichments of 1.4 - 9.6 a/o were measured in the standard deviation of 0.51 %, when the most suitable pairs of standard samples were used for each sample. A part of sources of systematic errors which were caused by each technique adopted was revealed throughout the measurements. And also, it was recognized that the LMRI's values of enrichment were certified precisely, and the UO 2 standards were very useful for enrichment measurements in the four techniques of gamma-ray spectrometry used here. (author)

ParShield: A computer program for calculating attenuation parameters of the gamma rays and the fast neutrons

International Nuclear Information System (INIS)

Elmahroug, Y.; Tellili, B.; Souga, C.; Manai, K.

2015-01-01

Highlights: • Description of the theoretical method used by the ParShield program. • Description of the ParShield program. • Test and validation the ParShield program. - Abstract: This study aims to present a new computer program called ParShield which determines the neutron and gamma-ray shielding parameters. This program can calculate the total mass attenuation coefficients (μ t ), the effective atomic numbers (Z eff ) and the effective electron densities (N eff ) for gamma rays and it can also calculate the effective removal cross-sections (Σ R ) for fast neutrons for mixtures and compounds. The results obtained for the gamma rays by using ParShield were compared with the results calculated by the WinXcom program and the measured results. The obtained values of (Σ R ) were tested by comparing them with the measured results,the manually calculated results and with the results obtained by using MERCSFN program and an excellent agreement was found between them. The ParShield program can be used as a fast and effective tool to choose and compare the shielding materials, especially for the determination of (Z eff ) and (N eff ), there is no other programs in the literature which can calculate

Automatic Sample Changing System for Gamma-Ray Spectrometry; Changeur Automatique d'Echantillons Pourla Spectrometrie Gamma; Avtomaticheskaya sistema dlya smeny obraztsov pri gamma-spektrometrii; Cambiador Automatico de Muestras para Espectroscopia Gamma

Energy Technology Data Exchange (ETDEWEB)

Lamson, K. C.; Sesko, W. J.; Nicholson, G. C. [Northeastern Radiological Health Laboratory, Winchester, MA (United States)

1965-10-15

emetteurs gamma presents dans les milieux biologiques a la concentration naturelle, il faut que l'ensemble de comptage utilise soit de haute sensibilite et, de plus, que la duree du comptage des echantillons soit longue - de une li plusieurs heures -, sil'onveut obtenir des donnees assez precises. Pour tirer le meilleur parti possible de l'appareil de comptage par spectroscopie gamma a faible mouvement propre qui est couteux, il faut l'utiliser sans interruption. Cela suppose la presence continue de personnel ou une complete automatisation comprenant le changement des echantillons et l'enregistrement des donnees. Le memoire a pour objet de decrire l'appareil automatique de comptage par spectrometrie gamma, concu et realise par le Northeastern Radiological Health Laboratory, a Winchester (Massachusetts). Le changeur d'echantillons est coupje a une enceinte blindee en acier, n'importe quelle enceinte blindee en vente dans le commerce avec porte sur le devant pouvant etre facilement adaptee a cette fin. Le changeur est capable de manipuler toute une variete d'echantillons, notamment des echantillons biologiques et medicaux. Il est constitue par un plateau rotatif destine a recevoir 16 echantillons, un dispositif code de positionnement des echantillons, un bras mecanique muni d'un electro-aimant qui introduit les echantillons dans l'enceinte et les en retire, et d'un levier automatique commandant l'ouverture et la fermeture de la porte de l'enceinte. Le changeur est completement integre a un analyseur multicanal et equipe de circuits de controle permettant d'arreter l'experience en cas de fonctionnement defectueux a un moment quelconque. Apres comptage pendant une periode determinee a l'avance, les donnees sont enregistrees par perforation sur bande puis traitees a l'aide d'une calculatrice IBM 1620. Ce premier modele de changeur d'echantillons, qui doit etre brevete incessamment, fonctionne depuis un an environ au Northeastern Radiological Health Laboratory. Il a ete

Gamma and X 93 spectrometry

International Nuclear Information System (INIS)

1994-05-01

The Meetings of Gamma and X 93 Spectrometry were held on 12-14 October 1993. The symposium was organized into six sessions: Instrumentation development, Nuclear matter measurement, Method and calibration, Medical applications, Environment survey (radioactive traces measurement), other applications (spent fuels analysis, various techniques). Separate abstracts were prepared for all the papers in this volume. (TEC)

Advances in continuous gamma-ray spectrometry and applications

International Nuclear Information System (INIS)

Gold, R.; McNeece, J.P.; Kaiser, B.J.

1984-07-01

Recent advances and applications in continuous Compton recoil gamma-ray spectrometry are described. Applications of continuous gamma-ray spectrometry are presented for: (1) Characterization of light water reactor (LWR) pressures vessel (PV) environments. (2) Assessment of fuel distributions for Three Mile Island Unit 2 (TMI-2) reactor recovery. (3) Measurement of LWR-PV-neutron exposure. The latest improvements attained with the Janus probe, a special in-situ configuration of Si(Li) detectors, are presented. The status of current efforts to extend the domain of applicability of this method beyond 3 MeV is discussed with emphasis on recent work carried out with Si(Li) detectors of much larger volume

Quantitative radiological characterization of waste. Integration of gamma spectrometry and passive/active neutron assay

Energy Technology Data Exchange (ETDEWEB)

Simone, Gianluca; Mauro, Egidio; Gagliardi, Filippo; Gorello, Edoardo [Nucleco S.p.A., Rome (Italy)

2016-06-15

The radiological characterization of drums through Non-Destructive Assay (NDA) techniques commonly relies on gamma spectrometry. This paper introduces the procedure developed in Nucleco for the NDA radiological characterization of drums when the presence of Special Nuclear Material (SNM) is expected/observed. The procedure is based on the integration of a gamma spectrometry in SGS mode (Segmented Gamma Scanner) and a passive/active neutron assay. The application of this procedure is discussed on a real case of drums. The extension of the integration procedure to other gamma spectrometry systems is also discussed.

Portable gamma-ray spectrometers and spectrometry systems

International Nuclear Information System (INIS)

Shebell, P.

1999-01-01

The current state-of-the-art in portable gamma-ray spectrometers and portable spectrometry systems is discussed. A comparison of detector performance and features of commercially available systems are summarised. Finally, several applications of portable systems are described. (author)

The Utilization of Background Spectrum to Calibrate Gamma Spectrometry

International Nuclear Information System (INIS)

Mahrouka, M. M.; Mutawa, A. M.

2004-01-01

Many developed countries have very poor reference standards to calibrate their nuclear instrumentations or may find some difficulties to obtain a reference standard. In this work a simple way for Gamma spectrometry calibration was developed. The method depends on one reference point and additional points from the background. The two derived equations were applied to the analyses of radioactive nuclides in soil and liquid samples prepared by IAEA laboratories through AL MERA Project. The results showed the precision of the methodology used, as well as, the possibility of using some points in the background spectrum as a replacement for reference standards of Gamma spectrometry calibration. (authors)

Performance of gamma spectrometry counting system

International Nuclear Information System (INIS)

Yii Mei Wo; Maziah Mahmud

2007-01-01

Gamma spectrometry counting system widely used as tool to measure qualitative and quantitative gamma-ray emitters in a sample. Container size, sample to detector distance, sample volume are well known factors that affecting the quality of measurement. However, factor such as the age of the system was not been reported. Therefore, the objective of this study is to find out how the age factor affecting the quality of the measurement. From this study, it is found that when the age of the system increased, the system tends to have higher lower limit of detection and poorer linearity showing that age factor do affecting the quality of measurement. (Author)

Some deficiencies and solutions in gamma ray spectrometry

International Nuclear Information System (INIS)

Westmeier, W.

1998-01-01

A number of problems in high-resolution gamma ray spectrometry as well as some deficiencies of existing computer programs for the quantitative evaluation of spectra are discussed and some practical solutions are proposed. (author)

The application of gamma-spectrometry to nuclear power plant (NPP) and environment

International Nuclear Information System (INIS)

Asgharizadeh, Farid.

1995-01-01

One of measuring systems is nuclear spectrometry, particularly Gamma-Ray Spectrometry, to measure and determine the radionuclide concentration within plant materials and environmental samples. There are four major applied techniques related to Nuclear Power Plant operation and environmental monitoring aspects. Some details about gamma ray spectrometry technique is discussed in chapter 2. The main emphasis is on the calculation of gamma-ray detector efficiency for different geometries, the minimum detectable activity concepts and dead-time correction. Also,some formula and relations are introduced. In chapter 3, the major applications of gamma-ray spectrometry for analysis of nuclear power plant and environmental samples are discussed. These applications are divided into four topics: Nuclear Fuel survey; based on the activity of fission products concentration in reactor coolant, two other applications are introduced: Fuel Burnup calculation and the calculation of rated activity of natural radionuclides in construction of materials which is the last and most important application: Measurement and determination of radionuclides activity concentr[[[[n in environmental samples is described through section 3.3 Sampling and measuring methods for research and monitoring aspects is evaluated. Some data about sample preparation methods such as pretreatment and solubilization procedures are presented. Quantitative chemical separations of trace constituents from complex sample materials invariably require meticulous work by an analytical chemist. The radiochemical separation deals with this subject. Instrumental aspects, relate to gamma-ray spectrometry, quality assurance, presentation and reporting of results are described. In the experimental part, determination of radionuclides concentration in sediment sample is presented

Further development of IDGS: Isotope dilution gamma-ray spectrometry

International Nuclear Information System (INIS)

Li, T.K.; Parker, J.L.; Kuno, Y.; Sato, S.; Kamata, M.; Akiyama, T.

1991-01-01

The isotope dilution gamma-ray spectrometry (IDGS) technique for determining the plutonium concentration and isotopic composition of highly radioactive spent-fuel dissolver solutions has been further developed. Both the sample preparation and the analysis have been improved. The plutonium isotopic analysis is based on high-resolution, low-energy gamma-ray spectrometry. The plutonium concentration in the dissolver solutions then is calculated from the measured isotopic differences among the spike, the dissolver solution, and the spiked dissolver solution. Plutonium concentrations and isotopic compositions of dissolver solutions analyzed from this study agree well with those obtained by traditional isotope dilution mass spectrometry (IDMS) and are consistent with the first IDGS experimental result. With the current detector efficiency, sample size, and a 100-min count time, the estimated precision is ∼0.5% for 239 Pu and 240 Pu isotopic analyses and ∼1% for the plutonium concentration analysis. 5 refs., 2 figs., 7 tabs

The advantage of using the henry straight line in {gamma} spectrometry (1963); Interet de l'utilisation de la droite de henry en spectrometrie {gamma} (1963)

Energy Technology Data Exchange (ETDEWEB)

Jockey, [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

The Henry construction is a convenient way to interpret the total absorption peaks in gamma spectrometry by exploiting their statistical significance. It is so possible to determine graphically, and accurately, such values as: - position of the peak - resolution, etc. The main practical applications are considered. (author) [French] La construction de la droite de Henry fournit un moyen commode d'interpreter les pics d'absorption totale en spectrometrie gamma en exploitant leur signification statistique, il est ainsi possible de determiner graphiquement, avec precision, des notions telles que: - position du pic - resolution, etc. Les principales applications pratiques sont envisagees. (auteur)

Gamma ray spectrometry: applications in uranium prospecting and environment

International Nuclear Information System (INIS)

Lopez, Luis E.

1999-01-01

The experience in the use of gamma spectrometry for uranium prospecting and for the determination of natural radiation background is described. The basic principles of the techniques are also given. (author)

Determination of uranium and thorium using gamma spectrometry: a pilot study

Science.gov (United States)

Olivares, D. M. M.; Koch, E. S.; Guevara, M. V. M.; Velasco, F. G.

2018-03-01

This paper presents the results of a pilot experiment aimed at standardizing procedures for the CPqCTR/UESC Gamma Spectrometry Laboratory (LEG) for the quantification of natural radioactive elements in solid environmental samples. The concentrations of 238U, 232Th and 40K in two sediment matrix belonging to the Caetité region were determined, by using the absolute method with uncertainties about 5%. The results were obtained using gamma spectrometry with a high-resolution p-type HPGe detector. As a closure, the absorbed dose, radium equivalent activity and the annual effective dose were calculated.

Methodology for determination of activity of radionuclides by gamma spectrometry

International Nuclear Information System (INIS)

Fragoso, Maria da Conceicao de Farias; Oliveira, Victor Rogerio S. de; Oliveira, Mercia L.; Lima, Fernando Roberto de Andrade

2014-01-01

Due to the growth in the number of procedures that make use of the positron emission tomography (PET), there is a need for standard solutions for the calibration of the systems used for the measurement of the PET radiopharmaceutical (activimeter) in radiopharmacies and in nuclear medicine services. Among the existing alternatives for the standardization of radioactive sources, the method known as gamma spectrometry is widely used for short-lived radionuclides. The purpose of this study was to implement the methodology for standardization of the 18 F solutions by gamma spectrometry at the Regional Center for Nuclear Sciences of the Northeast (CRCN-NE/CNEN-NE), Brazil. (author)

An analysis of nuclear fuel burnup in the AGR-1 TRISO fuel experiment using gamma spectrometry, mass spectrometry, and computational simulation techniques

International Nuclear Information System (INIS)

Harp, Jason M.; Demkowicz, Paul A.; Winston, Philip L.; Sterbentz, James W.

2014-01-01

Highlights: • The burnup of irradiated AGR-1 TRISO fuel was analyzed using gamma spectrometry. • The burnup of irradiated AGR-1 TRISO fuel was also analyzed using mass spectrometry. • Agreement between experimental results and neutron physics simulations was excellent. - Abstract: AGR-1 was the first in a series of experiments designed to test US TRISO fuel under high temperature gas-cooled reactor irradiation conditions. This experiment was irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) and is currently undergoing post-irradiation examination (PIE) at INL and Oak Ridge National Laboratory. One component of the AGR-1 PIE is the experimental evaluation of the burnup of the fuel by two separate techniques. Gamma spectrometry was used to non-destructively evaluate the burnup of all 72 of the TRISO fuel compacts that comprised the AGR-1 experiment. Two methods for evaluating burnup by gamma spectrometry were developed, one based on the Cs-137 activity and the other based on the ratio of Cs-134 and Cs-137 activities. Burnup values determined from both methods compared well with the values predicted from simulations. The highest measured burnup was 20.1% FIMA (fissions per initial heavy metal atom) for the direct method and 20.0% FIMA for the ratio method (compared to 19.56% FIMA from simulations). An advantage of the ratio method is that the burnup of the cylindrical fuel compacts can be determined in small (2.5 mm) axial increments and an axial burnup profile can be produced. Destructive chemical analysis by inductively coupled mass spectrometry (ICP-MS) was then performed on selected compacts that were representative of the expected range of fuel burnups in the experiment to compare with the burnup values determined by gamma spectrometry. The compacts analyzed by mass spectrometry had a burnup range of 19.3% FIMA to 10.7% FIMA. The mass spectrometry evaluation of burnup for the four compacts agreed well with the gamma

Aircraft gamma-ray spectrometry in snow-water equivalent measurement

International Nuclear Information System (INIS)

Kuittinen, R.; Vironmaeki, J.

1979-01-01

During the winter periods 1976-1977 and 1977-1978 the Hydrological Office at the National Board of Waters and the Geological Survey of Finland carried out a joint study to evaluate usefuluess of gamma-ray spectrometry in snow-water equivalent measurement. A multichannel gamma-ray spectrometer was fitted in a DC-3 aircraft. Fourteen snow courses were operated using both the gravimetric method and the gamma-ray method. The snow courses were located in southern Finland in forest, swamp and agricultural land. The results shows that the gamma ray method can be considered suitable for use in Finnish conditions and the accuracy of the gamma-ray method is almost of the same magnitude as the accuracy of the gravimetric method. (Auth.)

Aircraft gamma-ray spectrometry in snow-water equivalent measurement

Energy Technology Data Exchange (ETDEWEB)

Kuittinen, R [National Board of Waters (Finland); Vironmaeki, J [Geological Survey of Finland

1979-01-01

During the winter periods 1976-1977 and 1977-1978 the Hydrological Office at the National Board of Waters and the Geological Survey of Finland carried out a joint study to evaluate usefuluess of gamma-ray spectrometry in snow-water equivalent measurement. A multichannel gamma-ray spectrometer was fitted in a DC-3 aircraft. Fourteen snow courses were operated using both the gravimetric method and the gamma-ray method. The snow courses were located in southern Finland in forest, swamp and agricultural land. The results shows that the gamma ray method can be considered suitable for use in Finnish conditions and the accuracy of the gamma-ray method is almost of the same magnitude as the accuracy of the gravimetric method.

Standard guide for high-resolution gamma-ray spectrometry of soil samples

CERN Document Server

American Society for Testing and Materials. Philadelphia

2004-01-01

1.1 This guide covers the identification and quantitative determination of gamma-ray emitting radionuclides in soil samples by means of gamma-ray spectrometry. It is applicable to nuclides emitting gamma rays with an approximate energy range of 20 to 2000 keV. For typical gamma-ray spectrometry systems and sample types, activity levels of about 5 Bq (135 pCi) are measured easily for most nuclides, and activity levels as low as 0.1 Bq (2.7 pCi) can be measured for many nuclides. It is not applicable to radionuclides that emit no gamma rays such as the pure beta-emitting radionuclides hydrogen-3, carbon-14, strontium-90, and becquerel quantities of most transuranics. This guide does not address the in situ measurement techniques, where soil is analyzed in place without sampling. Guidance for in situ techniques can be found in Ref (1) and (2). This guide also does not discuss methods for determining lower limits of detection. Such discussions can be found in Refs (3), (4), (5), and (6). 1.2 This guide can be us...

Decreasing of the detection limit for gamma-ray Spectrometry with the influence of sample treatment

International Nuclear Information System (INIS)

Karami, M.; Sadighzadeh, A.; Asgharizadeh, F.; Sardari, D.; Tavassoli, A.; Arbabi, A.; Hochaghani, O.

2009-01-01

Full text: In this study the ash method has been applied for environmental sample treatment in order to decrease of the detection limit in gamma-ray spectrometry for low level radioactivity measurements. Detection limit in gamma ray spectrometry is the smallest expectation value of the net counting rate that can be detected on given probabilities. The environmental test samples have been changed into ash using a suitable oven. The heating were made under controlled temperature to avoid the escape of some radionuclides such as radiocaesium. The ash samples were measured by high resolution gamma-ray spectrometry system. (author)

Determination of uranium and thorium using gamma spectrometry: A pilot study

Energy Technology Data Exchange (ETDEWEB)

Olivares, D.M.M.; Koch, E.S.; Manso Guevara, M.V.; Garcia Velasco, F., E-mail: diango.mo87@gmail.com [Universidade Estadual de Santa Cruz (UNESC), Ilhéus, BA (Brazil)

2017-07-01

This paper presents the results of a pilot experiment aimed at standardizing procedures for the CPqCTR/UESC Gamma Spectrometry Laboratory (LEG) for the quantification of natural radioactive elements in solid environmental samples. The concentrations of {sup 238}U, {sup 232}Th and {sup 40}K in two sediment matrix belonging to the Caetité region were determined, by using the absolute method with uncertainties about 5%. The results were obtained using gamma spectrometry with a high-resolution p-type HPGe detector. As a closure, the absorbed dose, radium equivalent activity and the annual effective dose were calculated. (author)

Efficiency curves of NIRR-1 gamma-ray spectrometry system at near ...

African Journals Online (AJOL)

The full-energy peak efficiency curves of the gamma-ray spectrometry for use with the Nigeria Research Reactor-1 (NIRR-1) have been determined by both theoretical and experimental at two source-detector positions for routine neutron activation analysis. Standard gamma ray sources were used to determine the efficiency ...

Area specific stripping of lower energy windows for AGS and CGS NaI systems[Airborne Gamma Spectrometry; Carbone Gamma Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Korsbech, U.; Aage, H.K. [Technical Univ. of Denmark (Denmark); Bystroem, S.; Wedmark, M. [Geological Survey of Sweden (Sweden); Thorshaug, S. [Norwegian Radiation Protection Agency (Norway); Bargholz, K. [Danish Emergency Management Agency (Denmark)

2005-05-01

The report describes the results from a NKS (Nordic Nuclear Safety Research) project aiming at examining the possibilities for extracting stripping factors for Airborne Gamma-ray Spectrometry (AGS) data and Carborne Gamma-ray Spectrometry (CGS) data directly from the recorded set of data, i.e. without having to calibrate the detector systems on beforehand. The project 'NKS project ASSb' has been carried out between 1 August 2004 and 31 March 2005 by a research group composed of persons from Technical University of Denmark (DTU), Danish Emergency Management Agency (DEMA), Geological Survey of Sweden (SGU), and Norwegian Radiation Protection Authority (NRPA). The AGS and CGS data sets used for the project were recorded by SGU, DEMA, NGU (Geological Survey of Norway), and SSI (Swedish Radiation Protection Institute). Most of the project effort has been directed towards analysing AGS and CGS data with point source signals recorded at the Barents Rescue 2001 LIVEX exercise at Boden in Sweden. Possibilities and limitations for the method have been identified. (au)

Correction for sample self-absorption in activity determination by gamma spectrometry

International Nuclear Information System (INIS)

Galloway, R.B.

1991-01-01

Gamma ray spectrometry is a convenient method of determining the activity of the radioactive components in environmental samples. Commonly samples vary in gamma absorption or differ in absorption from the calibration standards available, so that accurate correction for self-absorption in the sample is essential. A versatile correction procedure is described. (orig.)

Demonstration of a collimated in situ method for determining depth distributions using gamma-ray spectrometry

CERN Document Server

Benke, R R

2002-01-01

In situ gamma-ray spectrometry uses a portable detector to quantify radionuclides in materials. The main shortcoming of in situ gamma-ray spectrometry has been its inability to determine radionuclide depth distributions. Novel collimator designs were paired with a commercial in situ gamma-ray spectrometry system to overcome this limitation for large area sources. Positioned with their axes normal to the material surface, the cylindrically symmetric collimators limited the detection of un attenuated gamma-rays from a selected range of polar angles (measured off the detector axis). Although this approach does not alleviate the need for some knowledge of the gamma-ray attenuation characteristics of the materials being measured, the collimation method presented in this paper represents an absolute method that determines the depth distribution as a histogram, while other in situ methods require a priori knowledge of the depth distribution shape. Other advantages over previous in situ methods are that this method d...

The determination and use of radionuclide background in gamma spectrometry

International Nuclear Information System (INIS)

Zimmer, W.H.

1986-01-01

Background is the major component of gross photon peak area. Therefore, net area, nuclide activity, counting uncertainty, and limits of detection calculations are no better than the calculation of background. In this study, background in gamma spectrometry is explored in several of its aspects. Means are presented to reduce background. Standard practices are presented to be used in the acquisition of valid, relevant background data. Unified standard calculations with examples are presented in the use of background data to determine net count and counting uncertainty. L. A. Currie's latest calculations of Lower Limits of Detection (1) (LLD) as they apply to gamma spectrometry are reviewed. Finally, Maximum Undetected Activity (MUA), LLD, and Critical Level (CL) concepts and calculations are compared in sample spectra

Time sequence determination of parent–daughter radionuclides using gamma-spectrometry

Energy Technology Data Exchange (ETDEWEB)

Burnett, J. L.; Britton, R. E.; Abrecht, D. G.; Davies, A. V.

2017-05-06

The acquisition of time-stamped list (TLIST) data provides additional information useful to gamma-spectrometry analysis. A novel technique is described that uses non-linear least-squares fitting and the Levenberg-Marquardt algorithm to simultaneously determine parent-daughter atoms from time sequence measurements of only the daughter radionuclide. This has been demonstrated for the radioactive decay of short-lived radon progeny (214Pb/214Bi, 212Pb/212Bi) described using the Bateman first-order differential equation. The calculated atoms are in excellent agreement with measured atoms, with a difference of 1.3 – 4.8% for parent atoms and 2.4% - 10.4% for daughter atoms. Measurements are also reported with reduced uncertainty. The technique has potential to redefine gamma-spectrometry analysis.

Electron spin resonance and E.N.D.O.R. double resonance study of free radicals produced by gamma irradiation of imidazole single crystals; Etude par resonance paramagnetique electronique et double resonance E.N.D.O.R. des radicaux libres crees par irradiation gamma de monocristaux d'imidazole

Energy Technology Data Exchange (ETDEWEB)

Lamotte, B [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1970-07-01

Gamma irradiation of imidazole single crystals at 300 deg. K gives two radicals. Identification and detailed studies of their electronic and geometric structure have been made by ESR and ENDOR techniques. A study of the hydrogen bonded protons hyperfine tensor is made and let us conclude to the inexistence of movement and tunneling of these protons. The principal low temperature radical, produced by gamma irradiation at 77 deg. K has been also studied by ESR and a model has been proposed. (author) [French] L'irradiation gamma de monocristaux d'imidazole a 300 deg. K conduit a deux radicaux dont l'identification et l'etude detaillee des structures electroniques et geometriques ont ete obtenues par la resonance paramagnetique electronique (RPE) et la double resonance ENDOR. En particulier l'examen des protons de la liaison hydrogene permet de conclure, pour ceux-ci, a l'inexistence de tout mouvement par effet tunnel. De plus, l'analyse des spectres de RPE du radical principal cree par irradiation gamma de l'imidazole a 77 deg. K nous a permis de proposer un modele pour ce radical. (auteur)

Development of source-less efficiency calibration procedure for CeBr3 based gamma spectrometry system

International Nuclear Information System (INIS)

Verma, Amit K.; Narayani, K.; Pant, Amar D.; Bhosale, Nitin; Anilkumar, S.; Palani Selvam, T.

2018-01-01

Scintillation spectrometers are widely used in detection and spectrometry of gamma photons. Sodium Iodide (NaI(Tl)) is the most commonly used scintillation detector for gamma ray spectrometry. However for portable application that require higher efficiency and better resolution Cerium Bromide (CeBr 3 ) crystals are more suitable than NaI(Tl) crystals. CeBr 3 detectors have high light output (∼ 68,000 photons/MeV), good proportionality, fast response and better energy resolution (<4% for 662 keV of 137 Cs), which makes it very promising detector for gamma ray spectrometry. In the present work, experimental and Monte Carlo based efficiencies for CeBr 3 detector for 137 Cs and 60 Co were evaluated

Determination of uranium-235 by differential gamma spectrometry

International Nuclear Information System (INIS)

Suner, A.A.; La Gamma de Batistoni, A.M.G.; Botbol, J.

1974-12-01

A method for the determination of U-235 contained in solutions of uranium, by gamma spectrometry with Ge(Li) detector is described. Ra-226 is coprecipitated in BaSO 4 . The activity at 186 keV is measured, substracted by the corresponding of a standard. The detection limit is 1% of increment of U-235 over the standard. (author)

Laboratory of High resolution gamma spectrometry

International Nuclear Information System (INIS)

Mendez G, A.; Giber F, J.; Rivas C, I.; Reyes A, B.

1992-01-01

The Department of Nuclear Experimentation of the Nuclear Systems Management requests the collaboration of the Engineering unit for the supervision of the execution of the work of the High resolution Gamma spectrometry and low bottom laboratory, using the hut of the sub critic reactor of the Nuclear Center of Mexico. This laboratory has the purpose of determining the activity of special materials irradiated in nuclear power plants. In this report the architecture development, concepts, materials and diagrams for the realization of this type of work are presented. (Author)

Pulser injection with subsequent removal for gamma-ray spectrometry

International Nuclear Information System (INIS)

Hartwell, J.K.; Goodwin, S.G.; Johnson, L.O.; Killian, E.W.

1990-01-01

This patent describes a module for use with a gamma-ray spectroscopy system. The system includes a gamma-ray detector for detecting gamma-ray events and producing a signal representing the gamma-ray events, a converter responsive to the detector and capable of converting the signal to a spectrum, a storage memory responsive to the converter and capable of storing the spectrum at address locations in memory, and a pulser capable of injecting pulses into the signal produced by the detector. The module comprises: means for generating a logic pulse for controlling the pulser, the controlling means adapted for coupling to the pulser; means for generating separation of events logic to isolate the components of a combined gamma-ray---pulse spectrum, the separation of events logic means adapted for coupling to the converter and the storage memory with the capability of storing pulses at address locations in the storage memory separate from the gamma-ray events; means for receiving an imitating signal from the converter to generate a plurality of operations by the module; means for tracking variations in a gamma-ray---pulse spectrum brought on by external parameter changes; and means for interfacing with commercially developed gamma-ray spectrometry equipment

Dosage of cesium 137 in radioactive wastes by the application of sodium tetraphenylborate; Dosage du cesium 137 dans les effluents radioactifs par le tetraphenylborate de sodium

Energy Technology Data Exchange (ETDEWEB)

Testemale, G; Girault, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-07-01

A simple technique of the dosage of {sup 137}Cs has been developed. The technique consists in the formation of cesium tetraphenyl borate, followed by a double extraction with isoamyl acetate, and washing of the organic phase. The counting of known parts of the cesium solution assaying of its purity by {gamma} spectrometry enable the determination of the {sup 137}Cs. The yield is about 98 per cent. (authors) [French] Une technique simple du dosage du {sup 137}Cs a ete mise au point. Elle consiste en une double extraction du tetraphenylborate de cesium forme par l'acetate d'isoamyle suivie d'un lavage de la phase organique. Des comptages sur des parties aliquotes de la solution de cesium et un controle de purete par spectrometrie {gamma} permettent la determination de cet element. Rendement: environ 98 pour cent. (auteurs)

Study of {gamma}'s in Naiade; Etude des gamma de Naiade

Energy Technology Data Exchange (ETDEWEB)

Millot, J P; Rastoin, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Following a study of the gamma sources, the flux of gamma of different energies in the swimming pool is investigated. The biological dose can thus be obtained by calculation, and compared with the results given by photographic plates. The influence of photoneutrons is estimated by calculation, and research is being carried out on their influence on the thermal neutron flux curve on the axis of the uranium plate, with the plate emitting neutrons and with the plate protected by boral. (author) [French] Apres l'etude des sources de gamma, l'on etudie le flux de gamma de differentes energies dans la piscine. La dose biologique peut etre obtenue ainsi par le calcul et comparee avec les resultats donnes par les plaques photographiques. L'influence des photoneutrons est estimee par le calcul et l'on recherche leur influence sur la courbe de flux de neutrons thermiques sur l'axe de la plaque d'uranium, la plaque emettant des neutrons et la plaque protegee par du boral. (auteur)

Gammastic: towards a pseudo-gamma spectrometry in plastic scintillators

International Nuclear Information System (INIS)

Hamel, Matthieu; Dehe-Pittance, Chrystele; Coulon, Romain; Carrel, Frederick; Pillot, Philippe; Barat, Eric; Dautremer, Thomas; Montagu, Thierry; Normand, Stephane

2013-06-01

War against CBRN-E threats needs to continuously develop sensors with improved detection efficiency. More particularly, this topic concerns the NR controls for homeland security. A first analysis requires indeed a fast gamma spectrometry so as to detect potential special nuclear materials (SNM). To this aim, plastic scintillators could represent the best alternative for the production of large-scale, low-cost radiation portal monitors to be deployed on boarders, tolls, etc. Although they are known to be highly sensitive to gamma rays, due to their poor resolution, information relative to the nature of the SNM is tricky. Thus, only the Compton edge is obtained after interaction, and no information of the photoelectric peak is observed. This project concerns new developments on a possible pseudo-gamma spectrometry performed with plastic scintillators. This project is articulated on a combination of two developments: - The design of new materials most suitable for recovering the photoelectric peak after gamma interaction with the scintillator. This work concerns mainly plastic scintillators loading with heavy elements, such as lead or bismuth. - The analysis of the resulting signal with smart algorithms. This work is thus a pluri-disciplinary work performed at CEA LIST and embeds 4 main disciplines: MCNPX simulations (simulated spectra), chemistry of materials (preparation of various plastic scintillators with different properties), instrumentation (lab experiments) and smart algorithms. Really impressive results were obtained with the unfolding of simulated spectra at various energies (from 241 Am to 60 Co) and an innovative approach was proposed to counter-balance the quenching effect of luminescence by heavy elements in plastic scintillators. (authors)

Methods for the analysis of the overlapped peaks in analytical gamma-spectrometry

International Nuclear Information System (INIS)

Sterlinski, S.; Wasek, M.

1989-01-01

A new simple method for the quantitative analysis of the doublet peaks in Ge(Li) or HPGe gamma-spectrometry is presented. No assumptions on the shape of the peaks in gamma-ray spectra being measured are required. Special feature of the method proposed is its usefulness for the analysis of closed doublets. 7 refs., 6 figs. (author)

Design and fabrication of shielding for gamma spectrometry

International Nuclear Information System (INIS)

Mariano H, E.

1991-05-01

To have a system of gamma spectrometry in the Radiological Mobile Unit No. 1 (UMOR-1) was designed and manufactured an armor-plating appropriate to this, to make analysis of radioactive samples in place in the event of a radiological emergency, besides being able to give support to the Management of Radiological Safety, and even to give service of sample analysis of other Institutions. (Author)

In-pile gamma spectrometry and irradiation control at Osiris

International Nuclear Information System (INIS)

Farny, G.; Destot, M.; Corre, J.; Texier, D.; Faugere, J.L.; Mouchnino, M.

1975-01-01

A new gamma spectrometry facility is available near Osiris reactor core, at Saclay. This device enables nuclear fuels to be examined in loops or capsules all along their irradiation, a few minutes being sufficient to transfer the fuel from the irradiation place to the measurement bench. So, spacelike and timelike history of a lot of fission products, especially short-lived radionuclides, can be observed. Using such in-pile spectrometry device, of original design, allows to avoid radioactive decay corrections and the risks of any information less. Performance of the device is given together with some preliminary results and their interpretation [fr

In-situ gamma spectrometry method for determination of environmental gamma dose

International Nuclear Information System (INIS)

Conti, Claudio de Carvalho

1995-07-01

This work tries to establish a methodology for germanium detectors calibration, normally used for in situ gamma ray spectrometry, for determining the environmental exposure rate in function of the energy of the incident photons. For this purpose a computer code has been developed, based on the stripping method, for the computational spectra analysis to calculate the contribution of the partial absorption of the gamma rays (Compton effect) in the active and nonactive parts of the detector. The resulting total absorption spectrum is then converted to fluence distribution in function of the energy for the photons reaching the detector, which is then used to calculate the exposure rate or kerma in air. The unfolding and fluency convention parameters are determined by detector calibration using point gamma sources. The method is validated by comparison of the results against the calculated exposure rate at a point of interest for the standards. This method is used for the direct measurement of the exposure rate distribution in function of the energy at the site, in situ measurement technic, leading to rapid results during an emergency situation and also used for indoor measurements. (author)

Proinflammatory cytokines tumor necrosis factor-alpha and interferon-gamma alter tight junction structure and function in the rat parotid gland Par-C10 cell line.

Science.gov (United States)

Baker, Olga J; Camden, Jean M; Redman, Robert S; Jones, Jonathan E; Seye, Cheikh I; Erb, Laurie; Weisman, Gary A

2008-11-01

Sjögren's syndrome (SS) is an autoimmune disorder characterized by inflammation and dysfunction of salivary glands, resulting in impaired secretory function. The production of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) is elevated in exocrine glands of patients with SS, although little is known about the effects of these cytokines on salivary epithelial cell functions necessary for saliva secretion, including tight junction (TJ) integrity and the establishment of transepithelial ion gradients. The present study demonstrates that chronic exposure of polarized rat parotid gland (Par-C10) epithelial cell monolayers to TNF-alpha and IFN-gamma decreases transepithelial resistance (TER) and anion secretion, as measured by changes in short-circuit current (I(sc)) induced by carbachol, a muscarinic cholinergic receptor agonist, or UTP, a P2Y(2) nucleotide receptor agonist. In contrast, TNF-alpha and IFN-gamma had no effect on agonist-induced increases in the intracellular calcium concentration [Ca(2+)](i) in Par-C10 cells. Furthermore, treatment of Par-C10 cell monolayers with TNF-alpha and IFN-gamma increased paracellular permeability to normally impermeant proteins, altered cell and TJ morphology, and downregulated the expression of the TJ protein, claudin-1, but not other TJ proteins expressed in Par-C10 cells. The decreases in TER, agonist-induced transepithelial anion secretion, and claudin-1 expression caused by TNF-alpha, but not IFN-gamma, were reversible by incubation of Par-C10 cell monolayers with cytokine-free medium for 24 h, indicating that IFN-gamma causes irreversible inhibition of cellular activities associated with fluid secretion in salivary glands. Our results suggest that cytokine production is an important contributor to secretory dysfunction in SS by disrupting TJ integrity of salivary epithelium.

Assessment of measurement result uncertainty in determination of 210Pb with the focus on matrix composition effect in gamma-ray spectrometry

International Nuclear Information System (INIS)

Iurian, A.R.; Pitois, A.; Kis-Benedek, G.; Migliori, A.; Padilla-Alvarez, R.; Ceccatelli, A.

2016-01-01

Reference materials were used to assess measurement result uncertainty in determination of 210 Pb by gamma-ray spectrometry, liquid scintillation counting, or indirectly by alpha-particle spectrometry, using its daughter 210 Po in radioactive equilibrium. Combined standard uncertainties of 210 Pb massic activities obtained by liquid scintillation counting are in the range 2–12%, depending on matrices and massic activity values. They are in the range 1–3% for the measurement of its daughter 210 Po using alpha-particle spectrometry. Three approaches (direct computation of counting efficiency and efficiency transfer approaches based on the computation and, respectively, experimental determination of the efficiency transfer factors) were applied for the evaluation of 210 Pb using gamma-ray spectrometry. Combined standard uncertainties of gamma-ray spectrometry results were found in the range 2–17%. The effect of matrix composition on self-attenuation was investigated and a detailed assessment of uncertainty components was performed. - Highlights: • Confirmed 210 Pb certified values by LSC and alpha-particle spectrometry ( 210 Po). • Assessed 210 Po measurement result uncertainty by alpha-particle spectrometry. • Matrix composition effect on gamma-ray spectrometry measurement result uncertainty. • Assessment of 210 Pb measurement result uncertainty by gamma-ray spectrometry. • Comparison of techniques and approaches: ‘fit-for-purpose’ considerations.

Low level GAMMA0 spectrometry by beta-gamma coincidence

International Nuclear Information System (INIS)

Grigorescu, E.L.; Luca, A.; Razdolescu, A.C.; Ivan, C.

1999-01-01

Low level gamma spectrometry has a wide application, especially in environmental monitoring. Two variants, based on a beta-gamma coincidence technique, were studied. The equipment was composed of a beta detector and a Ge(Li) gamma detector (6% - relative efficiency), with the associated electronics. The gamma rays are recorded by the multichannel analyzer (4096 channels) only if the associated beta particles, which precede the gamma transitions, are registered in coincidence. Two types of beta detectors were used: plastic and liquid scintillators. In both cases, an external lead shield of 5 cm thick was used. The integral gamma background (50-1700 KeV) was reduced about 85 and 50 times, respectively. The corresponding MDA (Minimum Detectable Activity) values decreased about 1.5 and (3-7) times, respectively. The 2π sr plastic beta detector was placed on top the Ge(Li). The sample was inserted between the two detectors. The measurement time was 10 4 s. A 4π sr detector, built of the same material, was also studied, but it proved to be less advantageous because the background was reduced only 16 times; for a MDA reduction similar with that of the 2π sr variant, a longer measurement was needed (3.10 4 s). The other type of beta detector used, was a liquid scintillator. The dissolving of the samples in scintillator ensures a 4π sr measurement geometry. The vials with scintillator (10 ml volume) were placed on top the Ge(Li) and visualised by the photocathode of a phototube. This setup was surrounded by an enclosure which prevent the light penetration. The measurement time was 10 4 s. The only difficulty encountered in this low level measurement method is the accurate determination of the beta efficiency. A limitation is the possibility to measure only small mass samples. These variants are more simple and cheaper than others, previously studied. The advantage of the method is obvious when, instead of low MDA values, shorter measurement times are preferred. The

Measuring the radium quartet (228Ra, 226Ra, 224Ra, 223Ra) in seawater samples using gamma spectrometry

International Nuclear Information System (INIS)

Beek, P. van; Souhaut, M.; Reyss, J.-L.

2010-01-01

Radium isotopes are widely used in marine studies (eg. to trace water masses, to quantify mixing processes or to study submarine groundwater discharge). While 228 Ra and 226 Ra are usually measured using gamma spectrometry, short-lived Ra isotopes ( 224 Ra and 223 Ra) are usually measured using a Radium Delayed Coincidence Counter (RaDeCC). Here we show that the four radium isotopes can be analyzed using gamma spectrometry. We report 226 Ra, 228 Ra, 224 Ra, 223 Ra activities measured using low-background gamma spectrometry in standard samples, in water samples collected in the vicinity of our laboratory (La Palme and Vaccares lagoons, France) but also in seawater samples collected in the plume of the Amazon river, off French Guyana (AMANDES project). The 223 Ra and 224 Ra activities determined in these samples using gamma spectrometry were compared to the activities determined using RaDeCC. Activities determined using the two techniques are in good agreement. Uncertainties associated with the 224 Ra activities are similar for the two techniques. RaDeCC is more sensitive for the detection of low 223 Ra activities. Gamma spectrometry thus constitutes an alternate method for the determination of short-lived Ra isotopes.

Fully automated gamma spectrometry gauge observing possible radioactive contamination of melting-shop samples

International Nuclear Information System (INIS)

Kroos, J.; Westkaemper, G.; Stein, J.

1999-01-01

At Salzgitter AG, several monitoring systems have been installed to check the scrap transport by rail and by car. At the moment, the scrap transport by ship is reloaded onto wagons for monitoring afterwards. In the future, a detection system will be mounted onto a crane for a direct check on scrap upon the departure of ship. Furthermore, at Salzgitter AG Central Chemical Laboratory, a fully automated gamma spectrometry gauge is installed in order to observe a possible radioactive contamination of the products. The gamma spectrometer is integrated into the automated OE spectrometry line for testing melting shop samples after performing the OE spectrometry. With this technique the specific activity of selected nuclides and dose rate will be determined. The activity observation is part of the release procedure. The corresponding measurement data are stored in a database for quality management reasons. (author)

Development of isotope dilution gamma-ray spectrometry for plutonium analysis

Energy Technology Data Exchange (ETDEWEB)

Li, T.K.; Parker, J.L. (Los Alamos National Lab., NM (United States)); Kuno, Y.; Sato, S.; Kurosawa, A.; Akiyama, T. (Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan))

1991-01-01

We are studying the feasibility of determining the plutonium concentration and isotopic distribution of highly radioactive, spent-fuel dissolver solutions by employing high-resolution gamma-ray spectrometry. The study involves gamma-ray plutonium isotopic analysis for both dissolver and spiked dissolver solution samples, after plutonium is eluted through an ion-exchange column and absorbed in a small resin bead bag. The spike is well characterized, dry plutonium containing {approximately}98% of {sup 239}Pu. By using measured isotopic information, the concentration of elemental plutonium in the dissolver solution can be determined. Both the plutonium concentration and the isotopic composition of the dissolver solution obtained from this study agree well with values obtained by traditional isotope dilution mass spectrometry (IDMS). Because it is rapid, easy to operate and maintain, and costs less, this new technique could be an alternative method to IDMS for input accountability and verification measurements in reprocessing plants. 7 refs., 4 figs., 4 tabs.

Carborne gamma-ray spectrometry. Calibration and applications

International Nuclear Information System (INIS)

Aage, H.K.; Korsbech, U.; Bargholz, K.; Hovgaard, J.

2006-01-01

Calibration of carborne gamma-ray spectrometry systems for 137 Cs is carried out with a source successively placed at 791 positions within an area of 34 mx62 m. A computer model supplements the measurements. Hereby a sensitivity map for a surface contamination is generated as well as line and area sensitivities. Another model converts surface sensitivity to sensitivity for a deep contamination. Use of the sensitivity map for a non-homogeneous distribution of 137 Cs is demonstrated. Applications of line sensitivities for special tasks are discussed

Research on 3-D terrain correction methods of airborne gamma-ray spectrometry survey

International Nuclear Information System (INIS)

Liu Yanyang; Liu Qingcheng; Zhang Zhiyong

2008-01-01

The general method of height correction is not effectual in complex terrain during the process of explaining airborne gamma-ray spectrometry data, and the 2-D terrain correction method researched in recent years is just available for correction of section measured. A new method of 3-D sector terrain correction is studied. The ground radiator is divided into many small sector radiators by the method, then the irradiation rate is calculated in certain survey distance, and the total value of all small radiate sources is regarded as the irradiation rate of the ground radiator at certain point of aero- survey, and the correction coefficients of every point are calculated which then applied to correct to airborne gamma-ray spectrometry data. The method can achieve the forward calculation, inversion calculation and terrain correction for airborne gamma-ray spectrometry survey in complex topography by dividing the ground radiator into many small sectors. Other factors are considered such as the un- saturated degree of measure scope, uneven-radiator content on ground, and so on. The results of for- ward model and an example analysis show that the 3-D terrain correction method is proper and effectual. (authors)

The first results of measurements in military hospital laboratory for gamma spectrometry analysis

International Nuclear Information System (INIS)

Jankovic, Lj.; Pantelic, G.; Misovic, M.

1997-01-01

In this paper we present the basic features of the equipment for gamma spectrometry analysis and the first measurements results of the 134 Cs and 137 Cs activities. Gamma spectrum is measured using HP GE Detector. The obtained results show low level activities of the 134 Cs and 137 Cs in the environment. (author)

PEAKS: Computer code for solving partly overlapped photopeak in gamma spectrometry

International Nuclear Information System (INIS)

Jerez Vergueria, Sergio; Jerez Vergueria, Pablo

1996-01-01

The paper describes the main elements of the code according to purposes and contents. The PEAKS code is a useful tool of comfortable and easy handling for solving, partly overlapped photopeak in gamma spectrometry with NaI(Ti) detector

Collection and preparation of samples for gamma spectrometry

International Nuclear Information System (INIS)

Pan Jingquan

1994-01-01

The paper presents the basic principles of sample collection and preparation: setting up unified sampling program, methods and procedures, sample packing, transportation and storage, determination of sample quantity, sample pretreatment and preparation of samples to be analysed, etc. for gamma spectrometry. And the paper also describes briefly the main methods and special issues of sampling and preparation for the same environmental and biological samples, such as, air, water, grass, soil and foods

The gamma spectrometry a powerful tool for irradiated fuel and fission products release studies

International Nuclear Information System (INIS)

Pontillon, Y.; Roure, C.; Lacroix, B.; Martella, T.; Ducros, G.; Ravel, S.; Gleizes, B.

2003-01-01

Over the last decades, due to the potentially severe consequences of a nuclear incident and/or accident for surrounding populations as well as the environment, international safety authorities launched R and D programs in support of general policy on exploitation of nuclear energy. This increasing interest enabled starting of many research programs in CEA and particularly in Nuclear Energy Directorate (DEN). Most of them are devoted to (i) the source term of fission products (including gas) and actinides released from PWR fuel samples in normal or accident conditions, (ii) burn-up determination, (iii) isotopic repartition... by quantitative gamma spectrometry. In this context, the Department of Fuel Studies (DEC), part of the DEN, has acquired considerable experience in this field of research. In order to attain the required capabilities, specific technical facilities set up in shielded hot cells at the CEA-Grenoble and CEA-Cadarache have been developed. In particular, the researchers of the Department have developed several gamma scanning benches and a set of two thermal treatment devices, including the so-called 'VERCORS facility'. These devices are associated to on line quantitative gamma spectrometry, in order to measure emitted gas and fission products (FPs). The greatest asset of such installations is to ensure a high analytical experiments rate, and as a consequence to make parametrical approach of planned studies easier. The first part of the present communication focuses, on the one hand, on the peculiar aspects of the gamma spectrometry applied on irradiated fuel, mad on the other hand, on the technical aspect of the different facilities (i.e. quantitative gamma spectrometry apparatus and corresponding 'home made' software). The last part is devoted to the results which can be obtained with such installation. In particular, it will be explained how experimental programs on FPs and gas release in normal and/or accidental conditions can be conducted

Computer programs for data reduction and interpretation in plutonium and uranium analysis by gamma ray spectrometry

International Nuclear Information System (INIS)

Singh, R.K.; Moorthy, A.D.; Babbar, R.K.; Udagatti, S.V.

1989-01-01

Non destructive gamma ray have been developed for analysis of isotopic abundances and concentrations of plutonium and uranium in the respective product solutions of a reprocessing plant. The method involves analysis of gamma rays emitted from the sample and uses a multichannel analyser system. Data reduction and interpretation of these techniques are tedious and time consuming. In order to make it possible to use them in routine analysis, computer programs have been developed in HP-BASIC language which can be used in HP-9845B desktop computer. A set of programs, for plutonium estimation by high resolution gamma ray spectrometry and for on-line measurement of uranium by gamma ray spectrometry are described in this report. (author) 4 refs., 3 tabs., 6 figs

Results and comments on the gamma spectrometry examinations carried out on PWR and fast neutron fuel elements

International Nuclear Information System (INIS)

Pineira, Thomas; Mouchnino, Michel; Juste, Guy; Vignesoult, Nicole.

1980-05-01

The gamma spectrometry analyses on the fuel elements of PWR and fast neutron systems have experienced a significant growth in the CEA. This nondestructive, quick, inexpensive and quantitative method, seems to us particularly advantageous for qualifying the behavior of fuel under irradiation. However, in order to use it to the maximum, it must have reached a high degree of automation and the interpretation of the results must be the outcome of a coherent team that includes gamma spectrometry and fuel element specialists, since the growth of hot cell gamma spectrometry involves the processing of a considerable number of data upon which the quality of the results depends (large number of spectra per pencil analyzed, dimension of the 2000 or 4000 channel spectra, number of lines studied, etc.). Therefore the need to make the most of the information and, in particular, to present the results in a form suitable for direct processing in a minimum response time, requires a highly automated system. Further, the more specific results of gamma spectrometry correlated to the metallurgical results obtained in the laboratories should contribute efficiently to obtaining major information [fr

Gamma spectrometry analysis of fertilizers used in Costa Rica

International Nuclear Information System (INIS)

Loria, L.G.; Jimenez, R.; Badilla, M.

2002-01-01

Using the low level gamma spectrometry technique, the specific activity of natural and artificial isotopes present in national consumption fertilizers, supplied by local dealers, was quantified. The most outstanding isotope found in some of the fertilizers is U 235 , with an specific activity higher than the expected in this kind of product, which might mean that this isotope comes from imported raw material. (Author) [es

Determination of the sanguine iodine content by activation analysis (1962); Determination de l'iode sanguin par analyse d'activation (1962)

Energy Technology Data Exchange (ETDEWEB)

Kellershohn, C; Comar, D; Le Poec, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

Two methods of measuring the iodine content of the blood by activation analysis after 30 min irradiation in a flux of 6.10{sup 12} n/cm{sup 2}.s are described. One method includes a chemical separation of iodine before irradiation. The radioactivity of this specimen is determined on the basis of the amplitude of the iodine 128 photoelectric peak measured by {gamma}-spectrometry. The sensitivity of this method is about 10{sup -8} g. The other includes chemical separation after irradiation, and radioactivity is subsequently measured with a Geiger-Muller counter. The sensitivity of this second method is about 10{sup -10} g, sufficient for determination of the plasmatic mineral content. The advantages of activation analysis over the conventional method based on colorimetric measurement of the catalytic action of iodine in the oxidation of arsenious anhydride with ceric sulphate are discussed. Initial results obtained with this new form of analysis are detailed as are also the possibilities of measuring plasmatic proteic iodine by scintillation spectrometry without prior chemical separation. (authors) [French] Deux methodes de dosage de l'iode sanguin par analyse d'activation apres irradiation de 30 minutes a 6.10{sup 12} n/cm{sup 2} s sont decrites. L'une comprend une separation chimique de l'iode avant l'irradiation et la mesure de la radioactivite est effectuee a partir de l'amplitude du pic photo-electrique de l'iode 128 obtenu par spectrometrie-{gamma}. Sa sensibilite est de l'ordre de 10{sup -8} g. L'autre comprend une separation chimique de l'iode apres l'irradiation et la radioactivite de l'iode-128 est mesuree par comptage-{beta} avec un compteur Geiger. Sa sensibilite est de l'ordre de 10{sup -10} g, permettant d'envisager le dosage de l'iode mineral plasmatique. Les avantages de l'analyse d'activation sur la methode classique, basee sur la mesure colorimetrique de l'action catalytique de l'iode dans l'oxydation de l'anhydride arsenieux par le sulfate cerique

Fast-ion energy resolution by one-step reaction gamma-ray spectrometry

DEFF Research Database (Denmark)

Salewski, Mirko; Nocente, M.; Gorini, G.

2016-01-01

The spectral broadening of γ-rays from fusion plasmas can be measured in high-resolution gamma-ray spectrometry (GRS). We derive weight functions that determine the observable velocity space and quantify the velocity-space sensitivity of one-step reaction high-resolution GRS measurements in magne...

Study of cerenkov radiation. Production of {gamma} rays by electron accelerators; Etude du rayonnement de freinage. Production de rayons {gamma} par des accelerateurs d'electrons

Energy Technology Data Exchange (ETDEWEB)

Bernard, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

This study is a critical comparison of the theories of Bremsstrahlung. Experimental results obtained by the production of {gamma} radiation with electron accelerators are compared to the theoretical results in order to estimate the extent to which the various theories are valid. (author) [French] Cette etude est une synthese des theories du rayonnement de freinage. Des resultats experimentaux, obtenus par la production de rayonnements {gamma} avec des accelerateurs d'electrons, sont compares aux resultats theoriques afin d'evaluer les domaines de validite des diverses theories. (auteur)

Study on the Effects of Sample Density on Gamma Spectrometry System Measurement Efficiency at Radiochemistry and Environment Laboratory

International Nuclear Information System (INIS)

Wo, Y.M.; Dainee Nor Fardzila Ahmad Tugi; Khairul Nizam Razali

2015-01-01

The effects of sample density on the measurement efficiency of the gamma spectrometry system were studied by using four sets multi nuclide standard sources of various densities between 0.3 - 1.4 g/ ml. The study was conducted on seven unit 25 % coaxial HPGe detector gamma spectrometry systems in Radiochemistry and Environment Laboratory (RAS). Difference on efficiency against gamma emitting radionuclides energy and measurement systems were compared and discussed. Correction factor for self absorption caused by difference in sample matrix density of the gamma systems were estimated. The correction factors are to be used in quantification of radionuclides concentration in various densities of service and research samples in RAS. (author)

Spent fuel scanning using the gamma spectrometry bench at Osiris. Power and burnup determination

International Nuclear Information System (INIS)

Cerles, J.-M.; Simonet, Genevieve.

1976-01-01

The Saclay Nuclear Research Center is provided with an original gamma spectrometry facility located inside the pool of the Osiris reactor. It is intended for the gamma scanning of fuel elements irradiated in Osiris or elements of any other origin. The principal characteristics of this facility are given. Special emphasis is put on its [fr

Determination of 210Pb by direct gamma-ray spectrometry, beta counting via 210Bi and alpha-particle spectrometry via 210Po in coal, slag and ash samples from thermal power plant

International Nuclear Information System (INIS)

Seslak, Bojan; Vukanac, Ivana; Kandic, Aleksandar; Durasevic, Mirjana; Eric, Milic; Jevremovic, Aleksandar

2017-01-01

In order to compare three different techniques and estimate radiological impact, activity concentration of 210 Pb in coal, slag and ash samples from thermal power plant 'Nikola Tesla', Serbia, were measured, and results are presented in this study. Determination of 210 Pb was carried out in three ways: using HPGe gamma spectrometer and via in-growth of 210 Po and 210 Bi by alpha-particle spectrometry and proportional counting, respectively. The results obtained for three different techniques were compared. Statistical analysis and comparison of methods were carried out by combination of Z score and χ 2 statistical tests. Tests results, as well as values of measured activities concentrations obtained by alpha and gamma spectrometry, showed that gamma spectrometry is a valid alternative to time-consuming alpha spectrometry for low level activity measurements of 210 Pb. This remark is also valid even for gamma spectrometers with poor efficiency in low energy region. (author)

Mobile gamma spectrometry. Evaluation of the Resume 99 exercise

International Nuclear Information System (INIS)

Mellander, H.; Karlsson, S.; Aage, H.K.; Korsbech, U.; Lauritzen, B.; Smethurst, M.

2002-06-01

During the RESUME 99 exercise, the radiocaesium ( 137 Cs) activity in the surroundings of Gavle in central Sweden was ma p ped using car-borne gamma-ray spectrometry (CGS). The CGS data along with airborne gamma-ray spectrometry (AGS) data from the same area have been used to examine possible correlations between the CGS and AGS results, detector type and position, and geographical information, such as land-use and road type. The overall differences between various CGS results are small, while larger differences are found between AGS and CGS results. In general only little correlation was found with land-use and with road-type and width. The differences between AGS and CGS results arise because airborne detectors have a different field of view than a ground-based detector. From an analysis of the depth-dependency of AGS and CGS data for a depth-distributed source, it is found that the mean mass depth may be inferred from the ratio of AGS to CGS spectral count rates. Integration of AGS and CGS data requires a precise definition of quantities and units for reporting activity concentrations in a complicated geometry and care must be taken to translate AGS results into equivalent CGS quantities taking into account the spatial distribution of the radionuclides. (au)

Mobile gamma spectrometry. Evaluation of the Resume 99 exercise

Energy Technology Data Exchange (ETDEWEB)

Mellander, H.; Karlsson, S. [Swedish Radiation Protection Authority, Stockholm (Sweden); Aage, H.K.; Korsbech, U. [Technical Univ. of Denmark, Lyngby (Denmark); Lauritzen, B. [Risoe National Laboratory, Roskilde (Denmark); Smethurst, M. [Geological Survey of Norway, Trondheim (Norway)

2002-06-01

During the RESUME 99 exercise, the radiocaesium ({sup 137}Cs) activity in the surroundings of Gavle in central Sweden was ma{sup p}ped using car-borne gamma-ray spectrometry (CGS). The CGS data along with airborne gamma-ray spectrometry (AGS) data from the same area have been used to examine possible correlations between the CGS and AGS results, detector type and position, and geographical information, such as land-use and road type. The overall differences between various CGS results are small, while larger differences are found between AGS and CGS results. In general only little correlation was found with land-use and with road-type and width. The differences between AGS and CGS results arise because airborne detectors have a different field of view than a ground-based detector. From an analysis of the depth-dependency of AGS and CGS data for a depth-distributed source, it is found that the mean mass depth may be inferred from the ratio of AGS to CGS spectral count rates. Integration of AGS and CGS data requires a precise definition of quantities and units for reporting activity concentrations in a complicated geometry and care must be taken to translate AGS results into equivalent CGS quantities taking into account the spatial distribution of the radionuclides. (au)

The central gamma spectrometry laboratory of the GSF Institute of Radiation Protection

International Nuclear Information System (INIS)

Ruckerbauer, F.; Dietl, F.; Winkler, R.

1997-01-01

Since the middle of 1995 the WG Radioecology is operating the central gamma spectrometry laboratory of the GSF-Institute of Radiation Protection. The main scope of the laboratory is the gamma spectrometric analysis of samples within the research program of the institute and within joint programs with other institutes of the GSF research center. In the present report set-up and technical data of the measuring equipment, the central operating and data evaluation system and measures for quality assurance are described. At that time 18 semiconductor detectors are available for gamma spectrometric sample analysis which is standardized with respect to operation, evaluation algorithms, nuclide data, data safety and documentation. (orig.) [de

Determination of plutonium isotopic ratios and total concentration by gamma ray spectrometry

International Nuclear Information System (INIS)

Despres, Michele.

1980-11-01

A non-destructive method of analysis is being investigated for the control in situ of plutonium isotopic composition and total concentration in different matrix without preliminary calibration. The plutonium isotopic composition is determined by gamma-ray spectrometry using germanium detector systems. The same apparatus is used for direct measuring of the total plutonium concentration in solutions or solids by a differential attenuation technique based on two transmitted gamma rays with energies on both sides of the k shell absorption edge of plutonium [fr

Determination of the self-attenuation correction factor for environmental samples analysis in gamma spectrometry

International Nuclear Information System (INIS)

Santos, Talita O.; Rocha, Zildete; Knupp, Eliana A.N.; Kastner, Geraldo F.; Oliveira, Arno H. de; Oliveira, Arno H. de

2015-01-01

Gamma spectrometry technique has been used in order to obtain the activity concentrations of natural and artificial radionuclides in environmental samples of different origins, compositions and densities. These samples characteristics may influence the calibration condition by the self-attenuation effect. The sample density has been considered the most important factor. For reliable results, it is necessary to determine self-attenuation correction factor which has been subject of great interest due to its effect on activity concentration. In this context, the aim of this work is to show the calibration process considering the correction by self-attenuation in the evaluation of the concentration of each radionuclide to a gamma HPGEe detector spectrometry system. (author)

Proceedings of the International Symposium Advances in alpha, Beta- and Gamma-Ray spectrometry

International Nuclear Information System (INIS)

1997-01-01

The International Committee for Radionuclide Metrology (ICRM) is an association of radionuclide metrology laboratories whose membership is composed of delegates of these laboratories together with other scientists actively engaged in the study and applications of radioactivity. The scientific activities are carried out in the frame of six Working Groups. Two of them, the Alpha-Particle Spectrometry and the Gamma-and Beta-ray Spectrometry Working Groups held a common workshop in Pushkin, St. Petersburg, 18 to 20 September 1996, under the title Advances in Alpha-Beta-and Gamma-Ray Sepectrometry, at the kind invitation of the D.I. Mendeleyev Institute for Metrology. More than 30 people from 14 laboratories attended the meeting, and nineteen oral communications were presented, from which twelve were retained for publication an are included in these proceedings. (Author)

Laboratory of High resolution gamma spectrometry; Laboratorio de espectrometria gamma de alta resolucion

Energy Technology Data Exchange (ETDEWEB)

Mendez G, A.; Giber F, J.; Rivas C, I.; Reyes A, B

1992-01-15

The Department of Nuclear Experimentation of the Nuclear Systems Management requests the collaboration of the Engineering unit for the supervision of the execution of the work of the High resolution Gamma spectrometry and low bottom laboratory, using the hut of the sub critic reactor of the Nuclear Center of Mexico. This laboratory has the purpose of determining the activity of special materials irradiated in nuclear power plants. In this report the architecture development, concepts, materials and diagrams for the realization of this type of work are presented. (Author)

Iterative inversion of gamma or alpha spectrometry data

International Nuclear Information System (INIS)

Nordemann, D.J.R.

1985-12-01

Gamma - and alpha ray spectrometry data are processed by an iterative regression method (Wolberg, 1967) to obtain the activities or yields of radionuclides. This method, applied to Nuclear Geophysics Research, permits the use of either selected energy bands or of all the channels one by one. It may be easily programmed in popular microcomputers and offers many advantages such as the use of mixtures of radionuclides for the calibrations and the treatment of the uncertainties on the measurements and results. Several conclusions about the method and options of nuclear data processing are presented. (Author) [pt

Airborne gamma-ray spectrometry and computer data processing

International Nuclear Information System (INIS)

Raghuwanshi, S.S.; Bhishma Kumar; Tewari, S.G.

1993-01-01

The physical basis for the measurement of radioelemental concentrations of U, Th, and K on the surface of the earth by airborne gamma-ray spectrometry (AGRS) are described in this paper. The yield of an infinite radioactive plane source for a particular gamma energy helps to know the sampled volume in AGRS, the ground coverage, the ground resolution, the effective planning of the survey, flight line spacing, and sampling time. The infinite source-yield enables the determination of the attenuation coefficients in actual surveys and lays down the criteria for a standard test strip. Scattering of gamma-rays in matter is discussed in order to study its influence in the measurements from air. The theoretical gamma-ray spectrum from terrestrial U, Th, and K are discussed in contrast to its realistic picture which poses problems for their direct use for measurements. The criterion of FWHM (full width at half maximum) and inter-energy distance with their yields is described which finally helps to select the energy windows for (window and MCA) AGRS system. Factors which affect the measurements of radioelemental concentration in AGRS surveys include both correctable and non-correctable ones. Correctable factors are : (a) non-terrestrial sources of gamma-rays aircraft, cosmic, and airborne background (H) (B); (b) interference due to gamma-scattering inter channel effects (l); (c) height variations (H) due to navigation and topography; (d) temperature (T) of ambient air; and (e) pressure (P) of air at flying altitude. For removal of background effects, measurements over test strip and calibration pads are necessary for making the corrections in the order - BIH. These methods are described in the paper. The non-correctable factors include effects, due to terrain moisture, vegetation, and others. The possible ways to eliminate these effects are also briefly described. (author). 17 refs., 13 figs

Design and fabrication of shielding for gamma spectrometry; Diseno y fabricacion de blindaje para espectrometria gamma

Energy Technology Data Exchange (ETDEWEB)

Mariano H, E

1991-05-15

To have a system of gamma spectrometry in the Radiological Mobile Unit No. 1 (UMOR-1) was designed and manufactured an armor-plating appropriate to this, to make analysis of radioactive samples in place in the event of a radiological emergency, besides being able to give support to the Management of Radiological Safety, and even to give service of sample analysis of other Institutions. (Author)

Application of neutron activation analysis to the study of impurities in molybdenum, tungsten and nuclear graphite; Application de l'analyse par activation neutronique a l'etude des impuretes dans le molybdene, le tungstene et le graphite nucleaire

Energy Technology Data Exchange (ETDEWEB)

Pinte, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-10-15

A neutron activation method is described for the analysis of a maximum number of foreign elements in molybdenum, tungsten and graphite. The various elements are isolated using a systematic separation programme; the elements are subsequently analysed qualitatively and quantitatively using {gamma}-spectrometry. By this method are dosed 27 elements in molybdenum and tungsten, and 20 elements in graphite to which can be added those elements which are already the object of routine analysis: V, Mn, Si, P, S, Cl and 14 rare earths. (author) [French] On decrit une methode d'analyse par activation neutronique permettant de doser un maximum d'elements etrangers dans le molybdene, le tungstene et le graphite. En suivant un schema de separation systematique, on isole les differents elements dont les analyses qualitatives et quantitatives sont ensuite effectuees par spectrometrie {gamma}. Par cette methode, on dose 27 elements dans le molybdene et le tungstene, 20 elements dans le graphite, auxquels on peut encore ajouter les elements doses couramment: V, Mn, Si, P, S, Cl et 14 Terres Rares. (auteur)

Homogenization of food samples for gamma spectrometry using tetramethylammonium hydroxide and enzymatic digestion

International Nuclear Information System (INIS)

Kimi Nishikawa; Abdul Bari; Abdul Jabbar Khan; Xin Li; Traci Menia; Semkow, T.M.

2017-01-01

We have developed a method of food sample preparation for gamma spectrometry involving the use of tetramethylammonium hydroxide (TMAH) and/or enzymes such as α-amylase or cellulase for sample homogenization. We demonstrated the effectiveness of this method using food matrices spiked with "6"0Co, "1"3"1I, "1"3"4","1"3"7Cs, and "2"4"1Am radionuclides, homogenized with TMAH (mixed salad, parmesan cheese, and ground beef); enzymes (α-amylase for bread, and cellulase for baked beans); or α-amylase followed by TMAH (cheeseburgers). Procedures were developed which are best compromises between the degree of homogenization, accuracy, speed, and minimizing laboratory equipment contamination. Based on calculated sample biases and z-scores, our results suggest that homogenization using TMAH and enzymes would be a useful method of sample preparation for gamma spectrometry samples during radiological emergencies. (author)

X-ray fluorescence and gamma-ray spectrometry combined with multivariate analysis for topographic studies in agricultural soil

International Nuclear Information System (INIS)

Castilhos, Natara D.B. de; Melquiades, Fábio L.; Thomaz, Edivaldo L.; Bastos, Rodrigo Oliveira

2015-01-01

Physical and chemical properties of soils play a major role in the evaluation of different geochemical signature, soil quality, discrimination of land use type, soil provenance and soil degradation. The objectives of the present study are the soil elemental characterization and soil differentiation in topographic sequence and depth, using Energy Dispersive X-Ray Fluorescence (EDXRF) as well as gamma-ray spectrometry data combined with Principal Component Analysis (PCA). The study area is an agricultural region of Boa Vista catchment which is located at Guamiranga municipality, Brazil. PCA analysis was performed with four different data sets: spectral data from EDXRF, spectral data from gamma-ray spectrometry, concentration values from EDXRF measurements and concentration values from gamma-ray spectrometry. All PCAs showed similar results, confirmed by hierarchical cluster analysis, allowing the data grouping into top, bottom and riparian zone samples, i.e. the samples were separated due to its landscape position. The two hillslopes present the same behavior independent of the land use history. There are distinctive and characteristic patterns in the analyzed soil. The methodologies presented are promising and could be used to infer significant information about the region to be studied. - Highlights: • Characterization of topographic sequence of two hillslopes from agricultural soil. • Employment of EDXRF and gamma-ray spectrometry data combined with PCA. • The combination of green analytical methodologies with chemometric studies allowed soil differentiation. • The innovative methodology is promising for direct characterization of agricultural catchments

Measuring the radium quartet ({sup 228}Ra, {sup 226}Ra, {sup 224}Ra, {sup 223}Ra) in seawater samples using gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Beek, P. van, E-mail: vanbeek@legos.obs-mip.f [LEGOS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (CNRS/CNES/IRD/UPS), Observatoire Midi Pyrenees, 14 Avenue Edouard Belin, 31400 Toulouse (France); Souhaut, M. [LEGOS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (CNRS/CNES/IRD/UPS), Observatoire Midi Pyrenees, 14 Avenue Edouard Belin, 31400 Toulouse (France); Reyss, J.-L. [LSCE, Laboratoire des Sciences du Climat et de l' Environnement (CNRS/CEA/UVSQ), Avenue de la Terrasse, 91198 Gif-sur-Yvette (France)

2010-07-15

Radium isotopes are widely used in marine studies (eg. to trace water masses, to quantify mixing processes or to study submarine groundwater discharge). While {sup 228}Ra and {sup 226}Ra are usually measured using gamma spectrometry, short-lived Ra isotopes ({sup 224}Ra and {sup 223}Ra) are usually measured using a Radium Delayed Coincidence Counter (RaDeCC). Here we show that the four radium isotopes can be analyzed using gamma spectrometry. We report {sup 226}Ra, {sup 228}Ra, {sup 224}Ra, {sup 223}Ra activities measured using low-background gamma spectrometry in standard samples, in water samples collected in the vicinity of our laboratory (La Palme and Vaccares lagoons, France) but also in seawater samples collected in the plume of the Amazon river, off French Guyana (AMANDES project). The {sup 223}Ra and {sup 224}Ra activities determined in these samples using gamma spectrometry were compared to the activities determined using RaDeCC. Activities determined using the two techniques are in good agreement. Uncertainties associated with the {sup 224}Ra activities are similar for the two techniques. RaDeCC is more sensitive for the detection of low {sup 223}Ra activities. Gamma spectrometry thus constitutes an alternate method for the determination of short-lived Ra isotopes.

New possibilities in prompt gamma ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Borderie, B; Barrandon, J N [Centre National de la Recherche Scientifique, 45 - Orleans-la-Source (France). Lab. du cyclotron; Pinault, J L [Bureau de Recherches Geologiques et Minieres (BRGM), 45 - Orleans (France)

1977-01-01

Prompt gamma ray spectrometry has been used as an analytical tool for many years. The high level of background noise does, however, remain a major problem with this technique. From simple theoretical consideration, conditions (particle, energy) were determined to reduce significantly the background noise under irradiation. Alpha particles of 3.5 MeV were chosen. Some fifty elements were studied, of which 24 gave interesting results. The detection limits obtained for a sample of niobium were as follows: approximately 1 ppm (10/sup -6/g/g) for the light elements Li, B, F and Na, and between 50 ppm and 1% for the others. Numerous applications may be envisaged in the geo- and cosmo-sciences.

Classification of soil samples according to their geographic origin using gamma-ray spectrometry and principal component analysis

International Nuclear Information System (INIS)

Dragovic, Snezana; Onjia, Antonije

2006-01-01

A principal component analysis (PCA) was used for classification of soil samples from different locations in Serbia and Montenegro. Based on activities of radionuclides ( 226 Ra, 238 U, 235 U, 4 K, 134 Cs, 137 Cs, 232 Th and 7 Be) detected by gamma-ray spectrometry, the classification of soils according to their geographical origin was performed. Application of PCA to our experimental data resulted in satisfactory classification rate (86.0% correctly classified samples). The obtained results indicate that gamma-ray spectrometry in conjunction with PCA is a viable tool for soil classification

A new approach for the high-precision determination of the elemental uranium concentration in uranium ore by gamma-ray spectrometry

International Nuclear Information System (INIS)

Nagel, W.; Quik, F.

1993-01-01

A new approach for the determination of elemental uranium in uranium bearing ore, using high resolution gamma-ray spectrometry, was applied. Using a variant of the enrichment meter technique an agreement of better than 1% has been obtained between gamma-ray measurement results and the certified value obtained by other analytical methods. For the calibration of the gamma-ray spectrometer uranium reference samples have been used which are made available jointly in Europe and the USA as Certified Reference Materials for Gamma-ray Spectrometry (EC NRM 171 and NBS SRM 969, respectively). The measured ore has been put in a special designed container which ensured in all directions seen from the radiation window a uniform degree of infinite thickness of about 95%. The measurement results can be taken as an example for the applicability of gamma-ray spectrometry when high accuracy is required and under conditions where homogeneous distributed elemental uranium is embedded in a larger amount of matrix material. (author). 8 refs., 10 figs., 2 tabs., 2 appendices

Application of gamma ray spectrometry for evaluation of transfer factors in environmental matrices

International Nuclear Information System (INIS)

Rao, D.D.

2008-01-01

Gamma Ray Spectrometry (GRS) is performed using a variety of radiation detectors, to identify and determine radioactivity concentration of gamma emitting radionuclides qualitatively, in a wide range of samples. The samples can be of a high inventory power plant origin, NORM category or low level environmental samples, around a power plant. The method is usually applied to non-destructive analysis of environmental samples. However, it can also be applied to destructive analysis i.e. following extraction/separation of the analyte from the sample, if there is a need to pre-concentrate the analyte. The accuracy and precision of the method, depends on the quality of calibration, correction methods employed, stability of the system components, computational algorithms used, analysis of sources of uncertainties etc. The transfer factors among the environmental matrices are simple ratios, but the methodologies used in generating the respective concentrations have to be appropriately documented, including the validity of measurements. Validation mechanisms can include the results of international inter-comparison exercises, the certificates of standards issued by quality-accredited international laboratories. A few parameters involved in the qualitative analysis of gamma spectrometry are discussed here

Use of gamma spectrometry for analysis of three reference materials

International Nuclear Information System (INIS)

Kinova, L.

2004-01-01

All reference materials (Reference material A: weight = 49.23 g; Reference material B: weight = 36.08 g; Reference material C: weight = 26.18 g) were packed in 50 cm 3 polypropylene vials, sealed and measured consecutively three times at intervals of the average of 25 days. Low background gamma spectrometry system: HPGe detector with high energy resolution (FWHM for 1332 KeV of Co-60 is 1.9 KeV, Relative counting efficiency for the same energy is 21 %) was used. Results: All materials are of low activity and must be measured for a long time.The highest specific activity of a man-made radionuclides Cs-137 and Am-241 is in the material A. An instrumentally measurable activity of Pb-210 also can be observed in this material. Medium values are in the material B. The reference material C according to the specific activity seems to be a low natural radioactivity material with highest activity of natural nuclides Th-232 and Pa-234 (progeny of U-238). Conclusions: Gamma spectrometry is an useful tool for initial measurement of materials with low radioactivity. Such measurements give an orientation for the nuclides content and approximate activity in the material for the following radiochemical determinations

Comparison of Pu isotopic composition between gamma and mass spectrometry: Experience from IAEA-SAL

International Nuclear Information System (INIS)

Parus, J.L.; Raab, W.

1998-01-01

About 2000 Pu containing samples have been analysed during the last 8 years at SAL using gamma spectrometry (GS) in parallel with mass spectrometry (MS). Four different detectors have been used for the measurement of gamma-ray spectra and several versions of the MGA program have been used for spectra evaluation. The results of Pu isotopic composition obtained by both methods have neem systematically compared. Attempts to improve the agreement between GS and MS are described. This was done by adjustment of the emission probabilities for some gamma energies and the development of a new correlation equation for 242 Pu. These improvements have been applied for evaluation of two sets containing 320 and 404 samples, respectively analysed in 1991 and in 1992-93. The mean differences and their standard deviations between MS and GS were calculated, showing mean relative differences for 238-241 Pu isotopes in the range from 0.1 to 0.5% with standard deviations within ± 0.4 to ±1%. For 242 Pu these values are about 0.5% and ± 5%, respectively. (author)

Correlation analysis of measurement result between accelerator mass spectrometry and gamma counter

International Nuclear Information System (INIS)

Minamimoto, Ryogo; Cheng, C.; Oka, Takashi; Inoue, Tomio; Hamabe, Yoshimi; Shimoda, Marika

2010-01-01

The guidelines for microdosing in clinical trials were published in Japan in 2008 following the guidelines of the European Medicines Agency and the Food and Drug Administration. They recommend utilizing accelerator mass spectrometry (AMS) and positron emission tomography as candidates for monitoring drug metabolites in preclinical studies. We correlate the two methods by measuring appropriately labeled tissue samples from various mouse organs using both AMS and gamma counter. First, we measured the 14 C background levels in mouse organs using the AMS system. We then clarified the relationship between AMS and gamma counter by simultaneously administering 14 C-2-fluoro-2-deoxyglucose ( 14 C-FDG) and 18 F-2-fluoro-2-deoxyglucose ( 18 F-FDG). Tissue distribution was examined after 30 min, 1 h, 2 h and 4 h using the AMS system for 14 C-FDG and gamma counter for 18 F-FDG. Background 14 C levels were subtracted from the data obtained with radiotracer administration. The background 14 C concentration differed with tissue type measured. Background 14 C concentration in mouse liver was higher than in other organs, and was approximately 1.5-fold that in blood. The correlation coefficient (r) of the measurements between AMS ( 14 C-FDG) and gamma counter ( 18 F-FDG) was high in both normal (0.99 in blood, 0.91 in brain, 0.61 in liver and 0.78 in kidney) and tumor-bearing mice (0.95 in blood and 0.99 in tumor). The clearance profile of 18 F-FDG was nearly identical to that of 14 C-FDG measured with AMS. Accelerator mass spectrometry analysis has an excellent correlation with biodistribution measurements using gamma counter. Our results suggest that the combination of AMS and positron emission tomography (PET) can act as a complementary approach to accelerate drug development. (author)

Several experimental applications of gamma ray spectrometry on the analysis of uranium compounds

International Nuclear Information System (INIS)

Korob, Ricardo O.; Blasiyh Nuno, Guillermo A.

2002-01-01

Several experimental applications of gamma ray spectrometry on the analysis of uranium compounds and materials containing it are studied. Special attention is devoted to the correlation between experimental spectra and the decay chains of 235 U and 238 U contained in the analyzed samples. The following applications are discussed: enrichment determination without using calibration standards, determination of uranium concentration, intensities of the gamma rays emitted by the nuclides present in the decay chains of study and the activity of such nuclides. Because of its importance, detailed discussion about the former one is shown. In addition, preliminary results regarding the emission probabilities of the most important gamma rays of 234m Pa are also informed. (author)

Calibration of an air monitor prototype for a radiation surveillance network based on gamma spectrometry

International Nuclear Information System (INIS)

Baeza, A.; Caballero, J.M.; Corbacho, J.Á.; Ontalba-Salamanca, M.Á.; Vasco, J.

2014-01-01

The objective of this work is to present the improvements that have been made in quasi-real-time air radioactivity concentration monitors which were initially based on overall activity determinations, by incorporating gamma spectrometry into the current prototype. To this end it was necessary to develop a careful efficiency calibration procedure for both the particulate and the gaseous fractions of the air being sampled. The work also reports the values of the minimum detectable activity calculated for different isotopes and acquisition times. - Highlights: • Deficiencies of a commercial air monitoring system are detailed. • Gamma spectrometry introduction is the basis of the new prototype. • Efficiency calibration procedure is described for aerosol and gaseous fractions. • MDA is evaluated for different isotopes and acquisition times

New portability for in situ gamma-ray spectrometry from commercially available equipment

International Nuclear Information System (INIS)

Stanford, N.; Laurenzo, E.L.; McCurdy, D.E.

1984-01-01

In situ gamma-ray spectrometry has been employed by the staff of the Yankee Atomic Environmental Laboratory on a routine basis for more than five years. The original in situ gamma-ray spectrometry methodology was adopted from the techniques developed at the DOE Environmental Measurements Laboratory (Beck, DeCampo, and Gogolak 1972). The system consisted of a 110 cm 3 Ge(Li) detector in the vertical configuration in conjunction with typical laboratory nuclear instrumentation, as well as a medium-sized desktop computer, printer and disk drive. The equipment was transported in a small van having a shock-mounted cabinet and gasoline generator as an electrical power source. Recent availability of miniaturized spectrometry systems and powerful portable computers has enabled the upgrading of the 1977 vintage equipment to a system which is truly portable, light weight, compact and more reliable. The system to be described utilizes a portable intrinsic germanium detector, a small, 4096 channel pulse height analyzer (MCA) with anscillary components and a 24K, Hewlett Packard HP-75 computer with a small tape drive. When the equipment is used in the field, the system has enough capability to acquire and store a full 4096 channel gamma-ray spectrum and calculate the soil concentrations (pCi/g) and/or external radiation exposure rates for the commonly found naturally occurring, long-lived atmospheric nuclear weapons testing and nuclear power plant radionuclides. Subsequent data transfer to a larger desktop computer via available interfacing at the laboratory enables a full peak search and a more extensive evaluation of the data in order to calculate the soil concentrations and/or external radiation exposure rates for a selected 25 radionuclides. Experiences from the first season of operation are discussed

Smoothing technology of gamma-ray spectrometry data based on matched filtering

International Nuclear Information System (INIS)

Gu Min; Ge Liangquan

2009-01-01

Traditional method of smoothness of gamma-ray spectrometry data gives rise to aberration of spectra curves easily. The article improve convolution sliding transformation using idea of matched filtering. Gauss adding the exponential function instead of Gauss function is used as converting function. The improved method not only suppresses statistical fluctuation mostly but also keeps feature of spectra curves. Instance verified superiority of this new method. (authors)

Investigation of environmental samples by low-level gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Koehler, M [Nuclear Engineering and Analytics Rossendorf, Inc., Dresden (Germany); Niese, S [Nuclear Engineering and Analytics Rossendorf, Inc., Dresden (Germany)

1997-03-01

The average sample number in our laboratory is about 200 per month (12% technical solid state, 30% geological solid state, 6% geological solid state with low mass, 12% biological, 11% water directly, 25% water after chemical separation, 4% others). In 54% of the measurements the background continuum, and though the detection limit, is determined only by the detector himself and not by the compton continuum from high energy lines in the sample. Some examples in the presented work aim to prove the advantages of gamma ray spectrometry in the underground laboratory Felsenkeller. (orig./DG)

Comparative study of the gamma spectrometry method performance in different measurement geometries

International Nuclear Information System (INIS)

Diaconescu, C.; Ichim, C.; Bujoreanu, L.; Florea, I.

2013-01-01

This paper presents the results obtained by gamma spectrometry on aqueous liquid waste sample using different measurement geometries. A liquid waste sample with known gamma emitters content was measured in three different geometries in order to assess the influence of the geometry on the final results. To obtain low measurement errors, gamma spectrometer was calibrated using a calibration standard with the same physical and chemical characteristics as the sample to be measured. Since the calibration was performed with the source at contact with HPGe detector, the waste sample was also measured, for all the three geometries, at the detector contact. The influence of the measurement geometry on the results was evaluated by computing the relative errors. The measurements performed using three different geometries (250 ml plastic vial, Sarpagan box and 24 ml Tricarb vial) showed that all these geometries may be used to quantify the activity of gamma emitters in different type of radioactive waste. (authors)

Improvements in Applied Gamma-Ray Spectrometry with Germanium Semiconductor Detector

Energy Technology Data Exchange (ETDEWEB)

Brune, D; Hellstroem, S [AB Atomenergi, Nykoeping (Sweden); Dubois, J [Chalmers University of Technology, Goeteborg (Sweden)

1965-01-15

A germanium semi-conductor detector has in the present investigation been used in four cases of applied gamma-ray spectrometry. In one case the weak-activity contribution of Cs{sup 134} in Cs{sup 137} standard sources has been determined. The second case concerns the determination of K{sup 42} in samples of biological origin containing strong Na{sup 24} activities. In the third case the Nb{sup 94} and Nb{sup 95} activities from neutron-irradiated niobium foils used in the dosimetry of high neutron fluxes with long exposure times have been completely resolved and it has been possible to determine the ratio of the two activities with a high degree of accuracy. Finally, a Zr{sup 95} - Nb{sup 95} source has been analysed in a similar way with respect to its radiochemical composition. The resolution obtained also made possible a determination of the branching ratio of the two gamma-transitions in Zr{sup 95} and of the energies of the gamma-transitions of both nuclides.

Radioactivity Measurement in the Detergent Products by Gamma Spectrometry

International Nuclear Information System (INIS)

Ksouri, Abir

2009-01-01

Our study focuses on the evaluation of the level of radioactivity in the detergents. We have determined the specific activities of gamma emitting radionuclides belonging to the natural families of uranium, thorium and potassium using gamma spectrometry. The activities of radionuclides ( 235 U, 238U , 226 Ra, 232 Th, 40K) and their descendants are below the minimum detectable activity for dishwasher products, soaps, bleaches and shampoos, whereas they are found to levels considered very low (between 0,2 and 13 Bq/kg on average) in the products washes linens. These values are always lower than those of raw materials, what is explained by the conservation of radioactive material throughout the manufacturing process. The effective dose due to external exposure estimated below the regulatory standard recommended (<1 mSv / year), allows us to show that detergent products are not contaminated by radioactivity, are healthy and do not have harmful radiological impact on the consumer.

Study of different filtering techniques applied to spectra from airborne gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Wilhelm, Emilien; Gutierrez, Sebastien; Reboli, Anne; Menard, Stephanie; Nourreddine, Abdel-Mjid [Commissariat a l' Energie Atomique et aux energies alternatives - CEA, DAM, DIF F-91297 Arpajon (France); Arbor, Nicolas [Institut Pluridisciplinaire Hubert Curien, UMR 7178 Universite de Strasbourg-CNRS, 23 rue du Loess, BP 28, F-67037 Strasbourg Cedex 2 (France)

2015-07-01

One of the features of spectra obtained by airborne gamma spectrometry is low counting statistics due to the short acquisition time (1 s) and the large source-detector distance (40 m). It leads to considerable uncertainty in radionuclide identification and determination of their respective activities from the windows method recommended by the IAEA, especially for low-level radioactivity. The present work compares the results obtained with filters in terms of errors of the filtered spectra with the window method and over the whole gamma energy range. The results are used to determine which filtering technique is the most suitable in combination with some method for total stripping of the spectrum. (authors)

Remarks on the gamma-ray spectrometry for the determination of natural radioisotopes

International Nuclear Information System (INIS)

Kalita, S.; Niewodniczanski, J.

1987-01-01

Semiconductor low-energy gamma ray spectrometry is compared with the routinely used scintillation method (within higher energy range). Measurements of low-energy natural gamma radiation using a semiconductor detector permit the determination of radioactive equilibrium of the uranium series. In this method 238 U ( 234 Th) content is determined by 63 keV, 226 Ra by 186 keV and 214 Pb by 295 keV gamma rays. Using the same results one can calculate a radioactive equilibrium coefficient R, defined as concentration ratio 226 Ra/ 238 U and a 222 Rn emanation ratio E, defined as 1 - 214 Pb/ 226 Ra (concentrations in uranium equivalent units). The relative standard errors for the method are: 10 - 15% in case of radioisotope content and about 18% for R and E determination. 7 refs., 2 figs., 2 tabs. (author)

Neutron induced gamma spectrometry for on-line compositional analysis in coal conversion and fluidized-bed combustion plants

International Nuclear Information System (INIS)

Herzenberg, C.L.; O'Fallon, N.M.; Yarlagadda, B.S.; Doering, R.W.; Cohn, C.E.; Porges, K.G.; Duffey, D.

1977-01-01

Nuclear techniques involving relatively penetrating radiation may offer the possibility of non-invasive, continuous on-line instrumental monitoring which is representative of the full process stream. Prompt gamma rays following neutron capture are particularly attractive because the penetrating power of the neutrons and the, typically several MeV, capture gammas makes possible interrogation of material within a pipe. We are evaluating neutron capture gamma techniques for this application, both for elemental composition monitoring and for mass-flow measurement purposes, and this paper will present some recent work on composition analysis by neutron induced gamma spectrometry

Identification of. gamma. -irradiated spices by electron spin resonance (ESR) spectrometry

Energy Technology Data Exchange (ETDEWEB)

Uchiyama, Sadao; Kawamura, Yoko; Saito, Yukio (National Inst. of Hygienic Sciences, Tokyo (Japan))

1990-12-01

The electron spin resonance (ESR) spectrometry spectra of white (WP), black (BP) and red (Capsicum annuum L. var. frutescerns L., RP) peppers each had a principal signal with a g-value of 2.0043, and the intensities of the principal signals were increased not only by {gamma}-irradiation but also by heating. Irradiated RP also showed a minor signal -30G from the principal one, and the intensity of the minor signal increased linearly with increasing dose from 10 to 50 kGy. Since the minor signal was observed in RP irradiated at 10 kGy and stored for one year, but did not appear either after heating or after exposure to this signal is unique to {gamma}-irradiated RP and should therefore be useful for the identification of {gamma}-irradiated spices of Capsicum genus, such as paprika and chili pepper. The computer simulation of the ESR spectra suggested that the minor signal should be assigned to methyl radical and the principal signal mainly to a combination of phenoxyl and peroxyl radicals. Such minor signals were found in {gamma}-irradiated allspice and cinnamon among 10 kinds of other spices. (author).

Implementation and application of the gaussian decomposition software for NaI gamma-ray spectrometry data

International Nuclear Information System (INIS)

Zeng Lihui; Wang Nanping Tian Gui

2011-01-01

In order to extract the information of peaks in different energy from the data of overlapping peaks in environmental gamma spectrometer, a spectrum data Gaussian decomposition soft is designed based on least- square Gaussian fitting method. The interface of this software is friendly, it can complete the decomposition of overlapping peaks in gamma spectrometer quickly by the way of man-machines interactive. The result that applied gamma spectrometry to data analysis in the field measurement indicates that the Gaussian decomposition soft can efficiently extract 137 Cs from overlapping peaks which has significance to assess the human nuclide contamination of environment. (authors)

Results from an interlaboratory exercise on the determination of plutonium isotopic ratios by gamma spectrometry

International Nuclear Information System (INIS)

Ottmar, H.

1981-07-01

Results form interlaboratory comparison measurements on the determination of plutonium isotopic ratios by gamma spectrometry, organized by the ESARDA Working Group on Techniques and Standards for Nondestructive Analysis, are presented and discussed. Nine laboratories from nine countries or international organizations participated in the intercomparison exercise, which included both laboratories' own measurements on the plutonium isotopic reference materials NBS-SRM 946, 947, 948 and comparison analyses of gamma spectra from these materials distributed to the participating laboratories. Results from the intercomparison analyses have been used to reevaluate some gamma branching intensity ratios required for plutonium isotopic ratio measurements. (orig.) [de

Airborne gamma-ray spectrometry data processing using 1.5D inversion.

Science.gov (United States)

Druker, Eugene

2017-10-01

Standard processing of Airborne Gamma-Ray Spectrometry data generally gives good results when the measurement conditions are almost constant within several footprint area sizes, with the possible exception of flight height variations in a small range. In practice, deviations, such as large or abrupt changes of flight height and/or rugged terrain are not so rare and lead to certain problems. This article proposes a different approach where the solutions of inverse problems are used for data processing. The approach is quite natural in the processing of field data measured along the flight lines: it explicitly takes into account 1.5D survey models and flight parameters - from topography to sources distribution on the surface. Also, it clearly demonstrates that the inverse problem of the Airborne Gamma-Ray Spectrometry does not have a unique solution. This feature can be used in accordance with the underlying geological problem since various formulations of inverse problems can lead to various geological solutions. The use of the approach is illustrated by several examples given for flight lines and survey areas. This approach can be particularly useful in situations where geological, geophysical and/or geographic survey conditions are far from the standard assumptions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Correction for decay during counting in gamma spectrometry

International Nuclear Information System (INIS)

Nir-El, Y.

2013-01-01

A basic result in gamma spectrometry is the count rate of a relevant peak. Correction for decay during counting and expressing the count rate at the beginning of the measurement can be done by a multiplicative factor that is derived from integrating the count rate over time. The counting time substituted in this factor must be the live time, whereas the use of the real-time is an error that underestimates the count rate by about the dead-time (DT) (in percentage). This error of underestimation of the count rate is corroborated in the measurement of a nuclide with a high DT. The present methodology is not applicable in systems that include a zero DT correction function. (authors)

A comparative study of 232Th and 238U activity estimation in soil samples by gamma spectrometry and Neutron Activation Analysis (NAA) technique

International Nuclear Information System (INIS)

Rekha, A.K.; Anilkumar, S.; Narayani, K.; Babu, D.A.R.

2012-01-01

Radioactivity in the environment is mainly due to the naturally occurring radionuclides like uranium, thorium with their daughter products and potassium. Even though Gamma spectrometry is the most commonly used non destructive method for the quantification of these naturally occurring radionuclides, Neutron Activation Analysis (NAA), a well established analytical technique, can also be used. But the NAA technique is a time consuming process and needs proper standards, proper sample preparation etc. In this paper, the 232 Th and 238 U activity estimated using gamma ray spectrometry and NAA technique are compared. In the case of direct gamma spectrometry method, the samples were analysed after sealing in a 250 ml container. Whereas for the NAA, about 300 mg of each sample, after irradiation were subjected to gamma spectrometry. The 238 U and 232 Th activities (in Bq/kg) in samples were estimated after the proper efficiency correction and were compared. The estimated activities by these two methods are in good agreement. The variation in 238 U and 232 Th activity values are within ± 15% which are acceptable for environmental samples

Sodium fast reactor power monitoring using gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Coulon, R.; Normand, S.; Barbot, L.; Domenech, T.; Kondrasovs, V.; Corre, G.; Frelin, A.M. [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, CEA - Saclay DRT/LIST/DETECS/SSTM, Batiment 516 - P.C. no 72, Gif sur Yvette, F-91191 (France); Montagu, T.; Dautremer, T.; Barat, E. [CEA, LIST, Laboratoire Processus Stochastiques et Spectres (France); Ban, G. [ENSICAEN (France)

2009-06-15

This work deals with the use of high flux gamma spectrometry to monitor the fourth generation of sodium fast reactor (SFR) power. The simulation study part of this work has shown that power monitoring in a short time response and with a good accuracy is possible. An experimental test is under preparation at the French SFR Phenix experimental reactor to validate simulation studies. First, physical calculations have been done to correlate gamma activity to the released thermal power. Gamma emitter production rate in the reactor core was calculated with technical and nuclear data as the sodium velocity, the atomic densities, Phenix neutron spectrum and incident neutron cross-sections of reactions producing gamma emitters. A thermal hydraulic transfer function was used for modeling primary sodium flow in our calculations. For the power monitoring problematic, use of a short decay period gamma emitter will allow to have a very fast response system without cumulative effect. We have determined that the best tagging agent is 20F which emits 1634 keV energy photons with a decay period of 11 s. The gamma spectrum was determined by flux point and a pulse high tally MCNP5.1.40 simulation and shown the possibility to measure the signal of this radionuclide. The experiment will be set during the reactor 'end life testing'. The Delayed Neutron Detection (DND) room has been chosen as the best available location on Phenix reactor to measure this kind of radionuclide due to a short transit time from reactor core to measurement sample. This location is optimum for global power measurement because homogenized sampling in the reactor hot pool. The main spectrometer is composed of a coaxial high purity germanium diode (HPGe) coupled with a transistor reset preamplifier. The HPGe diode signal will be processed by the Adonis digital signal processing due to high flux and fast activity measurement. Post-processing softwares will be used to limit statistical problems of the

Optimization of measurement geometries used by the C.I.R. 'Gamma Spectrometry' working group

International Nuclear Information System (INIS)

Escarieux, M.

1979-01-01

The choice of measurement geometry is closely tied to the objective sought in gamma quantitative analysis which consists in identifying the radionuclides present in a sample and in determining the voluminal quantities. The too low efficiency of the detector and the levels of activity sought make it necessary to place the sample in contact with the casing of the detector and select a sample geometry suited to the measurement. In point of fact this choice is often determined by other criteria, availability of the container for example, and this leads the laboratories taking part in the 'Gamma Spectrometry' Working Group of the Comite d'Instrumentation de Radioprotection to adopt joint gamma measurement geometries [fr

Attempt of absolute analysis with spark source mass spectrometry; Essai d'analyse absolue par spectrometrie de masse a etincelles

Energy Technology Data Exchange (ETDEWEB)

Desjardins, M [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-10-01

By means of a graphical method developed in our laboratory, we have studied the linearity of the response of the MS-7 mass spectrometer for impurity determinations over a concentration range of 1 to 1000 ppm (parts per million of atoms). This method consist in transforming optical density measurements into 'true intensities', which are plotted on a logarithm-scale paper against the exposures. A moving transparent ruler graduated at the inverse scale of the exposures allows us to determine directly on the graph, the concentration of impurities in ppm. We have used this method for the determination of sensitivity coefficients in standard samples such as Al, Fe, Cu, Ni, Zr, and non conducting powders like SiO{sub 2} and Al{sub 2}O{sub 3}. This study shows that, for the samples studied, the sensitivity coefficients are practically independent of the matrix and the concentration. Moreover the results show the possibility of obtaining an absolute analysis by spark source mass spectrometry. (author) [French] Au moyen d'une methode graphique developpee ou laboratoire, nous avons etudie la linearite des determinations d'impuretes au spectrometre de masse, type MS-7, dans un domaine de concentration allont de 1 a 1000 ppm. Cette methode consiste en la transformation des mesures de densite optique en 'intensite vraie'. Ces dernieres mesures sont portees sur un graphique logarithmique et une reglette transparente graduee a l'inverse de l'echelle des expositions nous permet de determiner directement la teneur des impuretes en ppm (partie par million d'atomes). Nous avons utilise cette methode pour la determination des coefficients de sensibilite dans des echantillons etalons tels que Al, Fe, Cu, Ni, Zr, et des poudres non conductrices genre SiO{sub 2}, Al{sub 2}O{sub 3}. Cette etude a montre que, pour les echantillons etudies, les coefficients de sensibilite sont pratiquement independants de la matrice et de la concentration. De plus, les resultats obtenus montrent la

Preconcentration of natural protactinium from thorium concentrate with subsequent determination using Gamma (γ) spectrometry

International Nuclear Information System (INIS)

Raja, Naine; Swain, Kallola; Kayasth, S.R.; Pathassarathy, R.; Mathur, P.K.; Anil Kumar, S.

1999-01-01

A simple and efficient method has been developed to preconcentrate natural protactinium ( 231 Pa) from large size of thorium concentrate (5.0-100.0g) on Dowex 1 X 8 in acid medium. Gamma spectrometry, a powerful determination technique, has been used for quantitative determination of protactinium

Assessment of calibration parameters for an aerial gamma spectrometry system using Monte-Carlo technique

International Nuclear Information System (INIS)

Srinivasan, P.; Raman, Anand; Sharma, D.N.

2009-01-01

Aerial gamma spectrometry is a very effective method for quickly surveying a large area, which might get contaminated following a nuclear accident, or due to nuclear weapon fallout. The technique not only helps in identifying the contaminating radionuclide but also in assessing the magnitude and the extent of contamination. These two factors are of importance for the authorities to quickly plan and execute effective counter measures and controls if required. The development of Airborne gamma ray spectrometry systems have been reported by different institutions. The application of these systems have been reported by different authors. Radiation Safety Systems Division of the Bhabha Atomic Research Centre has developed an Aerial Gamma Spectrometry System (AGSS) and the surveying methodology. For an online assessment of the contamination levels, it is essential to calibrate the system (AGSS) either flying it over a known contaminated area or over a simulated contaminated surface by deploying sealed sources on the ground. AGSS has been calibrated for different detectors in aerial exercises using such simulated contamination on the ground. The calibration methodology essentially needs net photo-peak counts in selected energy windows to finally arrive at the Air to Ground Correlation Factors at selected flight parameters such as altitude, speed of flight and the time interval at which each spectrum is acquired. This paper describes the methodology to predict all the necessary parameters like photon fluence at various altitudes, the photo-peak counts in different energy windows, Air to Ground Correlation Factors(AGCF), the dose rate at any height due to air scattered gamma ray photons etc. These parameters are predicted for a given source deployment matrix, detector and altitude of flying using the Monte-Carlo code MCNP (Monte Carlo Neutron and Photon Transport Code.CCC-200, RSIC, ORNL, Tennessee, USA). A methodology to generate the completely folded gamma ray count

Determination of 7BE in soil sample by gamma spectrometry for erosion researchs

International Nuclear Information System (INIS)

Esquivel, Alexander D.; Kastner, Geraldo F.; Amaral, Angela M.; Monteiro, Roberto Pellacani G.; Moreira, Rubens M.

2015-01-01

Cosmogenic 7 Be is a natural radiotracer produced in the stratosphere and troposphere and reached to the Earth surface via wet and dry fallout and hence its measurement for research of erosion in soils is very significant. The 7 Be radio analyse based on gamma spectrometry technique has been a routine methodology for decades and although is the reference procedure is not free of analytical interference. 7 Be is a β-γ emitting radionuclide (Eγ = 477.59 keV, T½ = 53.12d) and depending on the chemical profile of the soil its determination is susceptible to 228 Ac (E γ = 478.40 keV, T½ = 6.15h) interference. The aim of this work was to establish an analytical protocol for the 7 Be determination in soil samples from Juatuba-Mg region in different sampling periods of dry and rainy seasons for erosion studies and to establish some methodologies for evaluating and correcting the interference level of 228 Ac in the 7 Be activity measurements by gamma spectrometry. (author)

Using airborne GAMMA-ray spectrometry (uranium, thorium, potassium) to quantify weathering and erosion processes

International Nuclear Information System (INIS)

Carrier, F.

2005-01-01

The airborne gamma-ray spectrometry survey carried out on the Armorican Massif provided soil contents in U, Th and K in ppm. Chemical and mechanical erosion processes within a homogeneous geological unit have been estimated using their variations and those of the 137 Cs. Our new approach, based on a multivariate analysis (hierarchic ascending classification), integrates the airborne gamma-ray spectrometry data, with their broad spatial distribution, together with precisely located station data (major elements, traces and isotopic geochemistry) resulting from a soil and river water erosion products survey. The total export of potassium was estimated in any point of an area catchment (50-m resolution) until 17+2 t/km 2 /a for a 50-m thick weathering profile. Erosion study by river sampling provide important biases, for the perennial river does not integrate the whole range of erosion products: the geochemical signature of the valleys is currently more represented than plateau areas. (author)

Argon activation analysis, application to dating by the potassium-argon method; Analyse par activation de l'argon. Application a la datation par la methode potassium-argon

Energy Technology Data Exchange (ETDEWEB)

Dumesnil, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

Activation analysis using radiogenic argon-40 has been applied to rock-dating by the K-Ar method. The argon is extracted from the sample, purified, activated to saturation in a flux of 2 X 10{sup 13} neutrons/cm{sup 2} sec{sup -1} and measured by gamma spectroscopy. The sensitivity obtained is such that it is possible to measure amounts of argon corresponding to age of a few thousand years only. However since it has not been possible to measure the amount of pollution of radiogenic argon by atmospheric argon with any accuracy, the measurable age limit is in fact of the order of MY. The method has been applied to basalts from the Mont-Dore region. The results obtained are in fairly good agreement with geological, stratigraphic and paleomagnetic data. (author) [French] L'analyse par activation de l'argon 40 radiogenique a ete appliquee a la datation des roches par la methode K-Ar. L'argon est extrait de l'echantillon, purifie, active a saturation dans un flux de 2.10{sup 13} neutrons.cm{sup -2}.s{sup -1} et mesure en spectrometrie gamma. La sensibilite obtenue est telle qu'il est possible de mesurer des quantites d'argon correspondant a des ages de quelques milliers d'annees seulement. Cependant la correction de pollution de l'argon radiogenique par l'argon atmospherique n'ayant pu etre etablie avec precision, la limite d'age mesurable pratique est de l'ordre de 1 Ma. La methode a ete appliquee aux basaltes de la region du Mont-Dore. Les ages obtenus sont en assez bon accord avec les donnees geologiques, stratigraphiques et paleomagnetiques. (auteur)

Mass determination of U-233 and Pu-239 by gamma spectrometry technique

International Nuclear Information System (INIS)

Moraes, M.A.P.V. de; Pugliesi, R.

1988-09-01

The gamma spectrometry technique has been used for masses determinations of uranium-233 and plutonium-239, granted by AERE-HARWELL. A high purity Ge semicondutor detector was used and the total efficiency curve was obtained for the counting system in the energy range 13 KeV to 135 KeV. The calculated values for the masses compared with that obtained by means of gravimetry technique. (author) [pt

Research on digital airborne gamma-ray spectrometry

International Nuclear Information System (INIS)

Ge Liangquan; Lai Wanchang; Zeng Guoqiang; Fan Zhenguo; Xiong Shengqing; Ni Weizhong

2010-01-01

Airborne Gamma-ray Spectrometry (AGS) is a main supporting technique for looking for uranium deposits and other non-radioactive mineral deposit, as well as for investigating environmental radiation pollution and monitoring nuclear equipment. This paper describes the newest achievements about the AGS instrument developed by Chengdu university of Technology. Those are: 1) the probe of AGS is composed of 5 NaI(Tl) + PMT scintillation counters with 10 x 10 x 40 mm size, and a special temperature sensor, preamplifier with circuit negative feedback and high voltage with lower electronic noise have been designed. 2)A Y/U double channel digital controlled gain amplifier for adjusting the spectrum drift finely and high speed ADC and CPLD are designed to perform digitalized spectroscopy and to improve the energy resolution and pulse through output rate (more than 100k/s). 3) Two self-stabilization spectrum loops have been designed for spectrum stability: The first loop is roughly adjusted by temperature and the second loop is finely by Kalman filter. 4) The significant characters of new AGS system are: the detective gamma energy range is 0.02∼10.0 MeV, the spectrum drift is ±1 channel, the collecting period is 0.5-1 s, and 20 NaI(Tl)+PMT scintillation counters can be operated at the same time. (authors)

Cosmic veto gamma-spectrometry for Comprehensive Nuclear-Test-Ban Treaty samples

International Nuclear Information System (INIS)

Burnett, J.L.; Davies, A.V.

2014-01-01

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is supported by a global network of monitoring stations that perform high-resolution gamma-spectrometry on air filter samples for the identification of 85 radionuclides. At the UK CTBT Radionuclide Laboratory (GBL15), a novel cosmic veto gamma-spectrometer has been developed to improve the sensitivity of station measurements, providing a mean background reduction of 80.8% with mean MDA improvements of 45.6%. The CTBT laboratory requirement for a 140 Ba MDA is achievable after 1.5 days counting compared to 5–7 days using conventional systems. The system consists of plastic scintillation plates that detect coincident cosmic-ray interactions within an HPGe gamma-spectrometer using the Canberra Lynx TM multi-channel analyser. The detector is remotely configurable using a TCP/IP interface and requires no dedicated coincidence electronics. It would be especially useful in preventing false-positives at remote station locations (e.g. Halley, Antarctica) where sample transfer to certified laboratories is logistically difficult. The improved sensitivity has been demonstrated for a CTBT air filter sample collected after the Fukushima incident

Cosmic veto gamma-spectrometry for Comprehensive Nuclear-Test-Ban Treaty samples

Science.gov (United States)

Burnett, J. L.; Davies, A. V.

2014-05-01

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is supported by a global network of monitoring stations that perform high-resolution gamma-spectrometry on air filter samples for the identification of 85 radionuclides. At the UK CTBT Radionuclide Laboratory (GBL15), a novel cosmic veto gamma-spectrometer has been developed to improve the sensitivity of station measurements, providing a mean background reduction of 80.8% with mean MDA improvements of 45.6%. The CTBT laboratory requirement for a 140Ba MDA is achievable after 1.5 days counting compared to 5-7 days using conventional systems. The system consists of plastic scintillation plates that detect coincident cosmic-ray interactions within an HPGe gamma-spectrometer using the Canberra LynxTM multi-channel analyser. The detector is remotely configurable using a TCP/IP interface and requires no dedicated coincidence electronics. It would be especially useful in preventing false-positives at remote station locations (e.g. Halley, Antarctica) where sample transfer to certified laboratories is logistically difficult. The improved sensitivity has been demonstrated for a CTBT air filter sample collected after the Fukushima incident.

Cosmic veto gamma-spectrometry for Comprehensive Nuclear-Test-Ban Treaty samples

Energy Technology Data Exchange (ETDEWEB)

Burnett, J.L., E-mail: jonathan.burnett@awe.co.uk; Davies, A.V.

2014-05-21

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is supported by a global network of monitoring stations that perform high-resolution gamma-spectrometry on air filter samples for the identification of 85 radionuclides. At the UK CTBT Radionuclide Laboratory (GBL15), a novel cosmic veto gamma-spectrometer has been developed to improve the sensitivity of station measurements, providing a mean background reduction of 80.8% with mean MDA improvements of 45.6%. The CTBT laboratory requirement for a {sup 140}Ba MDA is achievable after 1.5 days counting compared to 5–7 days using conventional systems. The system consists of plastic scintillation plates that detect coincident cosmic-ray interactions within an HPGe gamma-spectrometer using the Canberra Lynx{sup TM} multi-channel analyser. The detector is remotely configurable using a TCP/IP interface and requires no dedicated coincidence electronics. It would be especially useful in preventing false-positives at remote station locations (e.g. Halley, Antarctica) where sample transfer to certified laboratories is logistically difficult. The improved sensitivity has been demonstrated for a CTBT air filter sample collected after the Fukushima incident.

Final results of the PIDIE intercomparison exercise for the plutonium isotopic determination by gamma-ray spectrometry

International Nuclear Information System (INIS)

Morel, J.; Chauvenet, B.; Etcheverry, M.

1991-01-01

Final results from the PIDIE intercomparison exercise organised by the ESARDA Working Group on techniques and standards for non-destructive analysis are presented. The aim of this exercise carried out in 1988 was to test the gamma-ray spectroscopy methods used to determine the plutonium isotopic ratios in a large range of isotopic composition, in order to analyse the parameters and the error sources influencing the results. Sets of seven sealed samples of different plutonium isotopic composition were sent to nine participating laboratories. The final results with uncertainty indicators are reported; they are compared with complementary mass-spectrometry determinations. No important bias has been observed from this exercise. Significant improvements in plutonium isotopic determination by gamma-ray spectrometry come from both more elaborate spectrum analysis methods and better equipment

Determination of radon concentration in soil gas by gamma-ray spectrometry of olive oil

International Nuclear Information System (INIS)

Al-Azmi, Darwish; Karunakara, N.

2007-01-01

Measurements of radon concentration in soil gas have been carried out using a bubbling system in which the soil gas is drawn through an active pumping to bubble a liquid absorber (olive oil) for the deposition of the soil gas in it. After the bubbling process, the absorber is then taken for gamma-ray measurements. Gamma-ray photopeaks from the 214 Pb and the 214 Bi radon progeny are considered for the detection of the 222 Rn gas to study the concentration levels for radon soil gas. Results for some field measurements were obtained and compared with results obtained using AlphaGuard radon gas monitor. The technique provides a possible approach for the measurements of radon soil gas with gamma-ray spectrometry

Results of the 1988 interlaboratory comparison on the gamma spectrometry of dried whey

International Nuclear Information System (INIS)

Wiechen, A.; Tait, D.; Bundesanstalt fuer Milchforschung, Kiel

1988-01-01

Following the accident in Chernobyl in 1986 the number of units available for monitoring radioactivity, mainly gamma spectrometers, has been increased considerably in the Federal Republic of Germany. Furthermore, new legislation requires that all official monitoring laboratories verify the quality of their analytical technique by participating in interlaboratory comparison studies organized by Federal institutions. Such a study was therefore organized in March 1988. 86 laboratories collaborated on the gamma-spectrometry analysis of the radionuclides Cs-137, Cs-134 and K-40 in dried whey. This paper describes the statistical evaluation of the 144 sets of data received. The results of the study were surprisingly good. (orig./DG) [de

Specialized software utilities for gamma ray spectrometry. Final report of a co-ordinated research project 1996-2000

International Nuclear Information System (INIS)

2002-03-01

A Co-ordinated Research Project (CRP) on Software Utilities for Gamma Ray Spectrometry was initiated by the International Atomic Energy Agency in 1996 for a three year period. In the CRP several basic applications of nuclear data handling were assayed which also dealt with the development of PC computer codes for various spectrometric purposes. The CRP produced several software packages: for the analysis of low level NaI spectra; user controlled analysis of gamma ray spectra from HPGe detectors; a set of routines for the definition of the detector resolution function and for the unfolding of experimental annihilation spectra; a program for the generation of gamma ray libraries for specific applications; a program to calculate true coincidence corrections; a program to calculate full-energy peak efficiency calibration curve for homogenous cylindrical sample geometries including self-attenuation correction; and a program for the library driven analysis of gamma ray spectra and for the quantification of radionuclide content in samples. In addition, the CRP addressed problems of the analysis of naturally occurring radioactive soil material gamma ray spectra, questions of quality assurance and quality control in gamma ray spectrometry, and verification of the expert system SHAMAN for the analysis of air filter spectra obtained within the framework of the Comprehensive Nuclear Test Ban Treaty. This TECDOC contains 10 presentations delivered at the meeting with the description of the software developed. Each of the papers has been indexed separately

A Comparison between HPGe and NaI(Tl) detectors performance for gamma-spectrometry of low level measurement

International Nuclear Information System (INIS)

Poursiamy, N. H.; Tajikahmadi, H.; Mirshojaei, S. F.

2005-01-01

According to progressive usage of nuclear technology, it's important to prevent the contamination of the environment by man-made radioisotopes and exposures of human being. Radioisotopes can enter the human body by inhalation and ingestion which are the most important ways to internal exposures. Measurement of radiation level in foodstuff is one of the most important parameters in environmental safety which is performed according to constitution and standard tests in most countries such as Iran. Gamma spectrometry is carried out by NaI(Tl) and HPGe detector systems for foodstuffs. In this research operation of HPGe and NaI(Tl) detectors in gamma spectrometry with a standard radioactive source are investigated and compared. Also the result of NaI superiority in foodstuff radiation measurement given

Analysis of burnt nuclear fuel elements by gamma-spectrometry

International Nuclear Information System (INIS)

Lammer, M.

1978-01-01

Gamma-spectrometry allows a non-destructive determination of the fission and activation product content of spent nuclear fuel. The concentration of some of these products depends significantly on the so-called fuel parameters which describe the irradiation history and the fuel composition. The use of these dependences for deriving ''unknown fuel parameters'' from measured fission product activities is investigated in this work. Relevant application fields are burnup determination, fuel testing and inspections within the nuclear materials safeguards programme. The present thesis investigates how these dependences can be used to derive unknown fuel parameters. The possibilities and basic limitations of deriving information from a measured gamma spectrum are considered on principle. The main conclusion is that only ratios of fission product activities allow the development of an interpretation method which is generally applicable to all types of fuel from different reactors. The dependence of activity ratios on cooling time, irradiation time, integrated and final neutron flux, fuel composition, as well as fission and breeding rates are then investigated and presented graphically in a way suitable for applicaton. These relationships can be used for the analysis of spent fuel, and the detailed procedures, which depend on the applicaton field, are worked out in this work. In order to test the interpretation methods, samples of nuclear fuel have been irradiated and the gamma spectra analysed. The methods developed in this work can be applied successfully to the analysis of burnt fuel in the frame of fuel testing programmes and to safeguards verification purposes. If however, apart from a gamma spectrum, no information on the investigated fuel is available, the above-mentioned parameters can be derived with low accuracy only. (author)

Burn-Up Determination by High Resolution Gamma Spectrometry: Fission Product Migration Studies

Energy Technology Data Exchange (ETDEWEB)

Forsyth, R S; Blackadder, W H; Ronqvist, N

1967-04-15

The migration of solid fission products, in particular caesium and ruthenium, in high temperature oxide fuel can create a severe problem during the application of non-destructive burn-up methods employing gamma spectrometry, since caesium-137 is otherwise the most convenient long-lived burn-up monitor and ruthenium-106 can be used to distinguish between fissions in U-235 and Pu-239. As part of an experimental programme to develop burn-up methods, gamma scanning experiments have been performed on slices of irradiated UO{sub 2} pellets using a lithium-drifted germanium detector. The usefulness of the technique for migration studies has been demonstrated by comparing the fission product distribution curves across the specimen diameters with the microstructure of the specimens after polishing and etching.

Determination of radium isotopes in environmental samples by gamma spectrometry, liquid scintillation counting and alpha spectrometry: a review of analytical methodology

International Nuclear Information System (INIS)

Jia, Guogang; Jia, Jing

2012-01-01

Radium (Ra) isotopes are important from the viewpoints of radiation protection and environmental protection. Their high toxicity has stimulated the continuing interest in methodology research for determination of Ra isotopes in various media. In this paper, the three most routinely used analytical techniques for Ra isotope determination in biological and environmental samples, i.e. low-background γ-spectrometry, liquid scintillation counting and α-spectrometry, were reviewed, with emphasis on new methodological developments in sample preparation, preconcentration, separation, purification, source preparation and measurement techniques. The accuracy, selectivity, traceability, applicability and minimum detectable activity (MDA) of the three techniques were discussed. It was concluded that the MDA (0.1 mBq L −1 ) of the α-spectrometry technique coupled with chemical separation is about two orders of magnitude lower than that of low-background HPGe γ-spectrometry and LSC techniques. Therefore, when maximum sensitivity is required, the α-spectrometry technique remains the first choice. - Highlights: ► A review is made for determination of Ra isotopes in environmental samples. ► Gamma spectrometry, LSC and a-spectrometry are the main concerned radiometric approach. ► Sample preparation, preconcentration, separation and source preparation are discussed. ► The methods can analyse air, water, seawater, soil, sediment and foodstuffs samples. ► Some new data obtained recently from our laboratory for Ra method study are included.

Natural gamma-ray spectrometry as a tool for radiation dose and radon hazard modelling

International Nuclear Information System (INIS)

Verdoya, M.; Chiozzi, P.; De Felice, P.; Pasquale, V.; Bochiolo, M.; Genovesi, I.

2009-01-01

We reviewed the calibration procedures of gamma-ray spectrometry with particular emphasis to factors that affect accuracy, detection limits and background radiation in field measurements for dosimetric and radon potential mapping. Gamma-ray spectra were acquired in western Liguria (Italy). The energy windows investigated are centred on the photopeaks of 214 Bi (1.76 MeV), 208 Tl (2.62 MeV) and 40 K (1.46 MeV). The inferred absorbed dose rate and the radon flux are estimated to be lower than 60 nGy h -1 and 22 Bq m -2 h -1 , respectively.

Some considerations on the use of gamma spectrometry for Kr-85 determination at gaseous effluents in the nuclear industry and environmental samples

International Nuclear Information System (INIS)

Heras Iniquez, M.C.; Perez Garcia, M.M.; Travesi, A.

1983-01-01

The possibilities of using high resolution gamma ray spectrometry with GeLi semiconductor detector for measured the 0.514 KeV gamma radiation of Kr-B5 la explored, The detection limit of Kr-85 for a measuring time is 4.10 - 4 μCi with a counting time of 1000 minutes in a GeLi detector with a 20% efficiency relative to the INa (Tl). It is concluded that the use of gamma ray spectrometry for measuring the Kr-85 is not useful for environmental samples, but it can be used for the Kr-85 effluents control in Nuclear Stations. (Author) 26 refs

High-z semiconductor nuclear radiation detectors for room-temperature gamma-ray spectrometry

International Nuclear Information System (INIS)

Bornand, Bernard; Friant, Alain.

1978-09-01

A bibliographical review (182 articles of periodicals, conferences, reports, thesis and french patents) is presented, as addendum of the report CEA-BIB-210 (1974) on high-Z semiconductor compounds used as materials for the gamma and X-ray detection and spectrometry. This publication reviews issues from 1974 to 1977. References and summaries (in french) are incorporated into 182 bibliograhical notices. Index for authors, corporate authors, documents and periodicals, and subjects is included [fr

Evaluation of TASTEX task H: measurement of plutonium isotopic abundances by gamma-ray spectrometry

International Nuclear Information System (INIS)

Gunnink, R.; Prindle, A.L.; Asakura, Y.; Masui, J.; Ishiguro, N.; Kawasaki, A.; Kataoka, S.

1981-10-01

This report describes a computer-based gamma spectrometer system that was developed for measuring isotopic and total plutonium concentrations in nitric acid solutions. The system was installed at the Tokai reprocessing plant where it is undergoing testing and evaluation as part of the Tokai Advanced Safeguards Exercise (TASTEX). Objectives of TASTEX Task H, High-Resolution Gamma Spectrometer for Plutonium Isotopic Analysis, the methods and equipment used, the installation and calibration of the system, and the measurements obtained from several reprocessing campaigns are discussed and described. In general, we find that measurements for gamma spectroscopy agree well with those of mass spectrometry and of other chemical analysis. The system measures both freshly processed plutonium from the product accountability tank and aged plutonium solutions from storage tanks. 14 figures, 15 tables

Results from the first national in-situ gamma spectrometry survey of the United Kingdom

International Nuclear Information System (INIS)

Tyler, A.

2004-01-01

In-situ gamma spectrometry was introduced for the first time as part of a national soil and herbage pollution survey of the United Kingdom (UK) in 2002. The aim of introducing the in-situ approach was to evaluate its potential for replacing the conventional soil sampling approach in environmental monitoring. A total of 138 points were measured across the whole of the UK on a 50 km grid, encompassing a complete spectrum of soil types, geology (providing a range of natural radioactive backgrounds) and anthropogenic radioactivity (primarily derived from atmospheric weapons testing and Chernobyl fallout). Ten calibration sites were set up to derive an in-situ calibration from spatially distributed sampling points, designed to match the spatial response of the in-situ detector at 1 m above the ground. The importance of variations in the vertical activity distributions of 137 Cs on the in-situ detector calibration was verified and the advantages and disadvantages of implementing a forward scattering type approach for real time in-situ correction was evaluated. The accuracy of the in-situ calibrations was evaluated for the remaining 128 sites by independent comparison with soil core derived estimates of specific activity concentrations and inventories of a range of natural and anthropogenic gamma emitting radionuclides. Air kerma measurements were also derived from the in-situ gamma spectrometry measurements and compared with conventional GM tube derived estimates. (authors)

Use of gamma spectrometry for studying fuel plates

International Nuclear Information System (INIS)

Carteret, Y.; Schley, R.; Simonet, G.

1979-01-01

The programme of experimental irradiation performed at the CEA on the CARAMEL plate fuel was followed by gamma spectrometry, jointly with other techniques. The qualitative study of the distribution of fission products constitutes a source of information on the behavior of the fuel (temperature and structure) and enables its utilization limits to be predicted. The quantitative determination of short and long half life fission products makes it possible to calculate the specific power and specific burn-up. Carried out periodically, it is a means of checking the values obtained by the continuous measurement of cladding temperature, directly linked to the specific burn-up. At the end of irradiation, the results are compared against those achieved by neodymium analysis. The study of the change in gadolinium, a burnable poison, is an application of this technique [fr

Decision Threshold and Detection Limit in Spectrometric Measurements. Part 1: Application to Gamma Spectrometry

International Nuclear Information System (INIS)

Perez, C.; Gasco, C.; Lopez, M. A.

2010-01-01

This report summarised the author's lecture of the advanced gamma spectrometry course organised by CIEMAT. The characteristic limits determination in gamma spectrometry generally is obtained through the programming that the trade marks offers to the client with the objective of the automatic calculation of the activity concentrations existing in a sample. In this report, the examples shown in the ISO 11929 standard are compared to the programming realised by Genie 2k for determining characteristic limits. The main difference of both is located in the uncertainty calculations due to the efficiency calibration that is considered by ISO and not by Genie 2K. Through implementation in the software developed by trade marks will be possible to introduce this uncertainty and to assimilate to the calculation done by ISO 11929. In the second part of this report will be analyzed the more complicated samples of this application as counting in a whole body counter (following ISO-28218 about Performance Criteria for radio bioassay), multiplet, overlapping, addition of several peaks for obtaining the activity concentration, etc. (Author) 19 refs.

Sterilization by Gamma-Radiation of the Sodium Salt of p-Amino-Salicylic Acid; Sterilisation par irradiation gamma du sel sodique de l' acide p-amino salicylique; Sterilizatsiya gamma-oblucheniem natrievoj soli paraaminosalitsilovoj kisloty; Esterilizacion porirradiacion gamma dela sal sodica del acido p-aminosalicilico

Energy Technology Data Exchange (ETDEWEB)

Bellion, B.; Denti, E.; Massagli, A. [Sorin, Centro Ricerche Nucleari, Saluggia (Italy)

1963-11-15

Sodium p-amino-salicylate cannot be sterilized thermally. During manufacture or packing for medical purposes it must therefore be handled under sterilized conditions, with all the difficulties which this involves. The paper quotes experimental data to show that, using gamma irradiation, the product may be sterilized without damage and without the formation of substances harmful from the medical standpoint. (author) [French] Le p-amino salicylate de sodium ne peut Etre sterilise par la chaleur. Pour l'emploi de ce produit comme medicament on est donc oblige de l e manipuler tant pour la fabrication que pour l'emballage, dans des locaux steriles, avec toutes les difficultes qui s'ensuivent. Dans ce travail, les auteurs ont pu demontrer experimentalement la possibilite de steriliser le produit par irradiation gamma, sans endommager le produit et sans formation de substances nocives pour l'emploi medical. (author) [Spanish] El pamino salicilato de sodio no puede esterilizarse por vfa termica y, por lo tanto, para emplearlo como medicamento es preciso prepararlo y empaquetarlo en locales esterilizados, con las dificultades consiguientes; Los autores han demostrado experimentalmente que es posible esterilizar este compuesto por exposicion a los rayos gamma, sin alterarlo y sin que se formen substancias nocivas desde el punto de vista medico. (author) [Russian] Natrievaya sol' paraaminosalitsilovoj kisloty ne mozhet byt' sterilizovana pri pomoshchi nagreva, i dlya togo, chtoby ispol'zovat' ehtot produkt v kachestve medikamenta, nuzhno obrabatyvat' ego kak v protsesse proizvodstva, tak i pri upakovke v steril'nykh pomeshcheniyakh so vsemi vytekayushchimi otsyuda trudnostyami. V dannoj rabote avtory smogli ehksperimental'nym putem dokazat' vozmozhnost' sterilizatsii ehtogo produkta gamma-oblucheniem bez ushcherba dlya ehtogo produkta i bez obrazovaniya vrednykh veshchestv, chto pozvolyaet ego v meditsine. (author)

Influence of the irradiation by the {gamma} rays on various factors of immunity; Influence de l'irradiation par les rayons {gamma} sur divers facteurs d'immunite

Energy Technology Data Exchange (ETDEWEB)

Gaude, G; Coursaget, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

Exposed animals often present, in the days or weeks following the irradiation, heavy infectious lesions. The goal of this survey was to search the influence of the total irradiation by the gamma radiation from cobalt-60, on the organism, on the phagocytic power of the leukocytes and on the biogenesis of antibodies. The experiences were done on hundred animals, rabbits and guinea pigs. All irradiations have been achieved with eight sources of Cobalt 60 of 10 curies each, disposed on a sphere of 1 m, the animal living the region neighboring of the center. The intensity of the radiation, in these conditions, is about 100 roentgens per hour. (authors) [French] Les animaux irradies presentent souvent, dans les jours ou les semaines qui suivent l'irradiation, de graves lesions infectieuses. Le but de cette etude etait de rechercher l'influence de l'irradiation totale de l'organisme par le rayonnement gamma du cobalt 60 sur le pouvoir phagocytaire des leucocytes et sur la biogenese des anticorps. Les experiences portent sur une centaine d'animaux, lapins et cobayes. Toutes les irradiations ont ete realisees avec huit sources de Cobalt 60 de 10 curies chacune, disposees sur une sphere de 1 m de rayon, les animaux ocoupant la region voisine du centre. L'intensite du rayonnement est, dans ces conditions, d'environ 100 roentgens par heure. (auteurs)

Evaluation of gamma-spectrometry equipment for on-site inspection

International Nuclear Information System (INIS)

Burnett, J.L.; Milbrath, B.D.; Mueller, W.F.

2017-01-01

An On-site Inspection (OSI) is an important component of the verification regime of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), with the objective of gathering evidence of a possible Treaty violation. This includes the use of gamma-spectrometry equipment to identify 17 particulate radionuclides that are indicative of a nuclear explosion. This research provides an evaluation of high- (germanium), medium- (cadmium zinc telluride) and low-resolution (sodium iodide and lanthanum bromide) detectors using modelled radionuclide signatures from a nuclear explosion and Monte Carlo simulations of a detector response. The complex radionuclide signatures are shown to only be distinguishable using a high-resolution system for 1 week and 1 year post-detonation cases. (author)

Control of quality in spectrometry gamma of low level

CERN Document Server

Salazar, A

1997-01-01

Low level gamma spectrometry is a very precise technique to measure the concentration of nuclides present in different samples in Bq kg sup - sup 1. The quality control of the procedure and method used can be carried out by intercomparison exercises with world recognized institutions. During the last three years the Nuclear Physics Laboratory Of The University of Costa Rica (LAFNA) has been participating in the international quality assessment program (QAP) carried out by the Environmental Measurements Laboratory (EML), department of Energy, USA. The results show a very good agreement with the rest of the participant laboratories. This provides a very objective evaluation of the high precision of the methods used by LAFNA in low level spectroscopy measurements. (Author)

Control of quality in spectrometry gamma of low level

International Nuclear Information System (INIS)

Salazar, A.; Loria, G.

1997-01-01

Low level gamma spectrometry is a very precise technique to measure the concentration of nuclides present in different samples in Bq kg -1 . The quality control of the procedure and method used can be carried out by intercomparison exercises with world recognized institutions. During the last three years the Nuclear Physics Laboratory Of The University of Costa Rica (LAFNA) has been participating in the international quality assessment program (QAP) carried out by the Environmental Measurements Laboratory (EML), department of Energy, USA. The results show a very good agreement with the rest of the participant laboratories. This provides a very objective evaluation of the high precision of the methods used by LAFNA in low level spectroscopy measurements. (Author) [es

Evaluation of the natural radioactivity using thermoluminescence, gamma spectrometry and neutron activation techniques

International Nuclear Information System (INIS)

Fausto, A.M.; Otsubo, S.M.; Paes, W.S.; Yoshimura, E.M.; Okuno, E.; Hiodo, F.; Marques, L.S.; Alcala, A.L.

1996-01-01

The evaluation of the radiation dose in the living species due to the natural radioactivity is the main objective of this paper. The region that had been monitored was Intrusive Suite of Itu near to Sao Paulo city. Lateral[and depth distributions of natural radioactivity of the soil were determined using the techniques of thermoluminescence gamma spectrometry and neutron[activation. From the concentration in the soil of K-40 and radioactive elements of U and Th series experimentally determined, the dose due to gamma rays in air at 1 m from the soil was evaluated and the results compared with the direct dose measured with the portable rate-meter. (authors). 11 refs., 3 figs

A simple method for the deconvolution of 134 Cs/137 Cs peaks in gamma-ray scintillation spectrometry

International Nuclear Information System (INIS)

Darko, E.O.; Osae, E.K.; Schandorf, C.

1998-01-01

A simple method for the deconvolution of 134 Cs / 137 Cs peaks in a given mixture of 134 Cs and 137 Cs using Nal(TI) gamma-ray scintillation spectrometry is described. In this method the 795 keV energy of 134 Cs is used as a reference peak to calculate the activity of the 137 Cs directly from the measured peaks. Certified reference materials were measured using the method and compared with a high resolution gamma-ray spectrometry measurements. The results showed good agreement with the certified values. The method is very simple and does not need any complicated mathematics and computer programme to de- convolute the overlapping 604.7 keV and 661.6 keV peaks of 134 Cs and 137 Cs respectively. (author). 14 refs.; 1 tab., 2 figs

In situ gamma-ray spectrometry: A tutorial for environmental radiation scientists

International Nuclear Information System (INIS)

Miller, K.M.; Shebell, P.

1993-10-01

This tutorial is intended for those in the environmental field who perform assessments in areas where there is radioactive contamination in the surface soil. Techniques will be introduced for performing on-site quantitative measurements of gamma radiation in the environment using high resolution germanium detectors. A basic understanding of ionizing radiation principles is assumed; however, a detailed knowledge of gamma spectrometry systems is not required. Emphasized is the practical end of operations in the field and the conversion of measured full absorption peak count rates in a collected spectrum to meaningful radiological quantities, such as the concentration of a radionuclide in the soil, activity per unit area, and dose rate in the air. The theory of operation and calibration procedures will be covered in detail to provide the necessary knowledge to adapt the technique to site-specific problems. Example calculations for detector calibration are also provided

Determination Performance Of Gamma Spectrometry Co-Axial HPGE Detector In Radiochemistry And Environment Group, Nuclear Malaysia

International Nuclear Information System (INIS)

Mei-Woo, Y.

2014-01-01

Gamma Spectrometry System is used to measure qualitatively and quantitatively a gamma emitting radionuclide. The accuracy of the measurement very much depends on the performance specifications of the HPGe detectors. From this study it found that all the seven co-axial HPGe detectors in Radiochemistry and Environment Group, Nuclear Malaysia are in good working conditions base on the verification of performance specifications namely Resolution, Peak Shape, Peak-to-Compton ratio and Relative Efficiency against the warranted value from the manufacturers. (author)

Composite mapping experiences in airborne gamma spectrometry

International Nuclear Information System (INIS)

Bucher, B.

2014-01-01

During an international intercomparison exercise of airborne gamma spectrometry held in Switzerland 2007 teams from Germany, France and Switzerland were proving their capabilities. One of the tasks was the composite mapping of an area around Basel. Each team was mainly covering the part of its own country at its own flying procedures. They delivered the evaluated data in a data format agreed in advance. The quantities to be delivered were also defined in advance. Nevertheless, during the process to put the data together a few questions raised: Which dose rate was meant? Had the dose rate to be delivered with or without cosmic contribution? Activity per dry or wet mass? Which coordinate system was used? Finally, the data could be put together in one map. For working procedures in case of an emergency, quantities of interest and exchange data format have to be defined in advance. But the procedures have also to be proved regularly. (author)

The {sup 124}Sb activity standardization by gamma spectrometry for medical applications

Energy Technology Data Exchange (ETDEWEB)

Almeida, M.C.M. de, E-mail: marcandida@yahoo.com.b [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes, Instituto de Radioprotecao e Dosimetria, Comissao Nacional de Energia Nuclear (SEMRA/LNMRI/IRD/CNEN), Av. Salvador Allende s/n, Recreio, Rio de Janeiro, RJ, CEP 22780-160 (Brazil); Iwahara, A.; Delgado, J.U.; Poledna, R.; Silva, R.L. da [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes, Instituto de Radioprotecao e Dosimetria, Comissao Nacional de Energia Nuclear (SEMRA/LNMRI/IRD/CNEN), Av. Salvador Allende s/n, Recreio, Rio de Janeiro, RJ, CEP 22780-160 (Brazil)

2010-07-21

This work describes a metrological activity determination of {sup 124}Sb, which can be used as radiotracer, applying gamma spectrometry methods with hyper pure germanium detector and efficiency curves. This isotope with good activity and high radionuclidic purity is employed in the form of meglumine antimoniate (Glucantime) or sodium stibogluconate (Pentostam) to treat leishmaniasis. {sup 124}Sb is also applied in animal organ distribution studies to solve some questions in pharmacology. {sup 124}Sb decays by {beta}-emission and it produces several photons (X and gamma rays) with energy varying from 27 to 2700 keV. Efficiency curves to measure point {sup 124}Sb solid sources were obtained from a {sup 166m}Ho standard that is a multi-gamma reference source. These curves depend on radiation energy, sample geometry, photon attenuation, dead time and sample-detector position. Results for activity determination of {sup 124}Sb samples using efficiency curves and a high purity coaxial germanium detector were consistent in different counting geometries. Also uncertainties of about 2% (k=2) were obtained.

The activity of {gamma}-emitters as measured by ionisation chambers the determination of the specific emission coefficient {gamma} for some radio-elements (1961); Mesure de l'activite des emetteurs {gamma} par chambre d'ionisation. Determination du coefficient specifique d'emission {gamma} de quelques radioelements (1961)

Energy Technology Data Exchange (ETDEWEB)

Engelmann, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-06-15

The object of this work is to study techniques of measurement using the gamma ionisation chamber, making it possible either to measure the activities of radioactive sources, or to determine the specific emission coefficient {gamma} (or the coefficient K) of a given radioelement. The ionisation chambers studied belong to two categories: graphites cavity-chambers, and 4 {pi} {gamma} chambers. For the cavity-chamber measurements, the different correction factors of which account must be taken have been calculated, in particular the geometric and hygrometric corrections. The absorption and auto-absorption corrections have led to the introduction of the notion of the 'effective energy {gamma}' of a radioelement. In the case of 4 {pi} {gamma} chambers, it has been shown that appropriately shaped electrodes make it possible to improve their performances. One of the chambers described permits the measurement of {beta} emitters using the associated Bremsstrahlung. In order to measure the K coefficient of some radioelements, it has been found useful a 4 {pi} {gamma} chamber with graphite walls, the measurement being carried out by comparison with a radium standard. The validity of the method was checked with radioelements for whom the K coefficient values are well-known ({sup 24}Na, {sup 60}Co, {sup 131}I, {sup 198}Au). For other radioelements, the following values were obtained (expressed in r cm{sup 3} mc{sup -1} h{sup -1}): {sup 51}Cr: 0,18; {sup 56}Mn: 8,8; {sup 65}Zn: 3,05; {sup 124}Sb: 9,9; {sup 134}Cs: 9,3; {sup 137}Cs: 3,35; {sup 141}Ce: 0,46; {sup 170}Tm: 0,023; {sup 192}Ir: 24,9; {sup 203}Hg: 1,18; These values have been corrected for the contribution to the dose of the fluorescent radiation which may be emitted by the source, except in the case of Tm{sup 170}. In the last part of this work, the performances of the different electro-metric devices used were compared. (author) [French] Le but de ce travail est d'etudier les techniques de mesure par chambre d

Data processing in gamma spectrometry. Application to the decay schemes study; Traitement des informations en spectrometrie gamma application a l'etude de schemas de desintegration

Energy Technology Data Exchange (ETDEWEB)

Boulanger, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, departement d' electronique generale, service d' instrumentation nucleaire

1968-06-01

The purpose of this thesis is the processing of the data issued from a gamma spectrometer, and its applications to the decay schemes study. The mathematical analysis of the full energy peaks, in connection with the very good resolution of semi-conductor detectors, leads to a very accurate determination of the energies. The resolution of complex spectra by the least squares method, completed by a spectra generating process, allows the calculation of branching ratios. Then, the handling of the two dimensional experiments permits the coincidence exam. For each of these methods, the calculation principle, then the systematics tests realized in order to prove their validity and to determine their application ranges as well as some experimental results appropriate to illustrate their possibilities, are presented. The energies of some nuclides, frequently used as standards have been thus measured and the decay schemes of {sup 134}Cs and {sup 110m}Ag determined precisely. (author) [French] Cette these est consacree aux methodes de traitement des informations issues d'un spectrometre {gamma}, et a leur application a l'etude des schemas de desintegration: l'analyse mathematique des pics d'absorption totale, conjuguee avec l'excellent pouvoir de resolution des detecteurs semi-conducteurs, conduit a une determination tres precise des energies. La decomposition des spectres complexes par la methode des moindres carres, completee par un procede de generation de spectres, autorise le calcul des rapports de branchement. Enfin le depouillement des experiences biparametriques permet l'examen des coincidences. Pour chacune de ces methodes, on expose le principe des calculs et les essais systematiques effectues afin d'eprouver leur validite et de definir leurs domaines d'application, ainsi que quelques resultats experimentaux propres a illustrer leurs possibilites. Les energies de quelques isotopes utilises couramment comme etalons ont ainsi ete mesurees, et les schemas de

Determination of {sup 126}Sn half-life from ICP-MS and gamma spectrometry measurements

Energy Technology Data Exchange (ETDEWEB)

Bienvenu, P.; Arnal, N.; Comte, J. [CEA Cadarache DEN/DEC/SA3C/LARC, Paul Lez Durance (France); Ferreux, L.; Lepy, M.C.; Be, M.M. [CEA Saclay LIST LNE/LNHB, Gif sur Yvette (France); Andreoletti, G. [AREVA Cogema SL/UP2-800, Beaumont Hague (France)

2009-07-01

A new value of {sup 126}Sn half-life was determined by combination of inductively coupled plasma-mass spectrometry (ICP-MS) and gamma spectrometry measurements on purified sample solutions collected from nuclear fuel reprocessing. {sup 126}Sn was isolated through dissolution of fission product precipitates and liquid-liquid extraction with N-benzoyl-N-phenyl-hydroxylamine (BPHA). The abundance of {sup 126}Sn atoms together with the absence of interfering species in the analysed solutions made it possible to measure both mass concentration and nuclide activity with high precision and accuracy. This led to a {sup 126}Sn half-life value of 1.980 (57) x 10{sup 5} a. (orig.)

Demonstrating the European capability for airborne gamma spectrometry: results from the eccomags exercise

International Nuclear Information System (INIS)

Sanderson, D.C.W.

2003-01-01

Full text: Airborne gamma spectrometry has emerged over recent years as an important means for mapping deposited activity and dose-rates in the environment. Its importance to emergency response has been increasingly recognised in defining contaminated areas at rates of measurement and spatial density which simply cannot be matched using ground based methods. In Europe the practical capability for AGS has developed markedly over the period since the Chernobyl accident, and significant progress towards cooperation between AGS teams, and convergence of methodology has been made, largely as the result of work conducted with support from the Commission under Frameworks IV and V. As an important part of the ECCOMAGS project an international comparison was undertaken in SW Scotland in 2002 to evaluate the performance of AGS teams in comparison with established groundbased methods. The work included a composite mapping task whereby different AGS teams recorded data over adjacent areas, to demonstrate the potential for collective actions in emergency response. More than 70,000 observations were made from a 90x40 km area during a 3 day period by several European teams, and compiled within days to produce regional scale maps for 137-Cs contamination and environmental gamma dose-rates. In three disjoint common areas AGS and ground based observations were taken. The ground based work was split for practical reasons into two phases; a pre-characterization stage to define calibration sites, and a second stage where sampling of additional sites was undertake synchronously with the exercise to provide the basis for blind intercomparison with AGS. More than 800 laboratory gamma spectrometry measurements were taken in support of this activity, which in combination with in-situ gamma spectrometry and instrumental dose-rate measurements were used to define the ground-based estimates of 137-Cs activity per unit area and dose-rate. AGS for the common areas, included points for ground

Argon activation analysis, application to dating by the potassium-argon method; Analyse par activation de l'argon. Application a la datation par la methode potassium-argon

Energy Technology Data Exchange (ETDEWEB)

Dumesnil, P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

Activation analysis using radiogenic argon-40 has been applied to rock-dating by the K-Ar method. The argon is extracted from the sample, purified, activated to saturation in a flux of 2 X 10{sup 13} neutrons/cm{sup 2} sec{sup -1} and measured by gamma spectroscopy. The sensitivity obtained is such that it is possible to measure amounts of argon corresponding to age of a few thousand years only. However since it has not been possible to measure the amount of pollution of radiogenic argon by atmospheric argon with any accuracy, the measurable age limit is in fact of the order of MY. The method has been applied to basalts from the Mont-Dore region. The results obtained are in fairly good agreement with geological, stratigraphic and paleomagnetic data. (author) [French] L'analyse par activation de l'argon 40 radiogenique a ete appliquee a la datation des roches par la methode K-Ar. L'argon est extrait de l'echantillon, purifie, active a saturation dans un flux de 2.10{sup 13} neutrons.cm{sup -2}.s{sup -1} et mesure en spectrometrie gamma. La sensibilite obtenue est telle qu'il est possible de mesurer des quantites d'argon correspondant a des ages de quelques milliers d'annees seulement. Cependant la correction de pollution de l'argon radiogenique par l'argon atmospherique n'ayant pu etre etablie avec precision, la limite d'age mesurable pratique est de l'ordre de 1 Ma. La methode a ete appliquee aux basaltes de la region du Mont-Dore. Les ages obtenus sont en assez bon accord avec les donnees geologiques, stratigraphiques et paleomagnetiques. (auteur)

Nuclear energy - Waste-packages activity measurement - Part.1: high-resolution gamma spectrometry in integral mode with open geometry

International Nuclear Information System (INIS)

2004-01-01

ISO 14850:2004 describes a procedure for measurements of gamma-emitting radionuclide activity in homogeneous objects such as unconditioned waste (including process waste, dismantling waste, etc.), waste conditioned in various matrices (bitumen, hydraulic binder, thermosetting resins, etc.), notably in the form of 100 L, 200 L, 400 L or 800 L drums, and test specimens or samples, (vitrified waste), and waste packaged in a container, notably technological waste. It also specifies the calibration of the gamma spectrometry chain. The gamma energies used generally range from 0,05 MeV to 3 MeV. (authors)

Inventory control through gamma spectrometry at the enriched uranium laboratory

International Nuclear Information System (INIS)

Vicens, H.E.; Korob, R.O.; Goldschmidt, A.E.

1987-01-01

The enriched uranium laboratory processes alternatively uranium 90% and 20% enriched in U-235. The control of the isotopic composition of lots is made through mass spectrometry. In the laboratory operation wastes of both enrichments are generated and the recovery is performed with a time delay. To strengthen the administrative controls, avoid errors related to personnel replacement and/or deferred operations, it seemed suitable to adjust the gamma spectrometry as a fast, simple and available method to determine the enrichment. The laboratory work includes a wet and a dry process. The waste recovery necessarily involves the handling of liquid samples. For this reason, it was decided to determine the calibration curve for uranyl nitrate samples of fixed concentration and geometry. The samples were prepared from material purified through double precipitation of uranium peroxide and subsequent ignition to U 3 O 8 in platinum crucible, in tubular oven during 8 hours at 720 deg C. The preparation of samples, the measurement description, the discussion of results and the analysis of errors due to the presence of insoluble material and concentration changes are included. (Author)

In-situ gamma spectrometry method for determination of environmental gamma dose; Metodo de espectrometria gamma in situ para determinacao de dose gama ambiental

Energy Technology Data Exchange (ETDEWEB)

Conti, Claudio de Carvalho

1995-07-15

This work tries to establish a methodology for germanium detectors calibration, normally used for in situ gamma ray spectrometry, for determining the environmental exposure rate in function of the energy of the incident photons. For this purpose a computer code has been developed, based on the stripping method, for the computational spectra analysis to calculate the contribution of the partial absorption of the gamma rays (Compton effect) in the active and nonactive parts of the detector. The resulting total absorption spectrum is then converted to fluence distribution in function of the energy for the photons reaching the detector, which is then used to calculate the exposure rate or kerma in air. The unfolding and fluency convention parameters are determined by detector calibration using point gamma sources. The method is validated by comparison of the results against the calculated exposure rate at a point of interest for the standards. This method is used for the direct measurement of the exposure rate distribution in function of the energy at the site, in situ measurement technic, leading to rapid results during an emergency situation and also used for indoor measurements. (author)

Specialised software utilities for gamma-ray spectrometry. Computer codes to IAEA-TECDOC-1275

International Nuclear Information System (INIS)

2002-03-01

A Co-ordinated Research Project (CRP) on 'Software Utilities for Gamma-Ray Spectrometry' was initiated by the International Atomic Energy Agency in 1996. In the CRP several basic applications of nuclear data handling were assayed which also dealt with the development of PC computer codes for various spectrometric purposes. This CD-ROM contains the following computer codes, produced under the CRP: ANGES, a program for the user controlled analysis of gamma-ray spectra from HPGe detectors; NUCL M AN, a program for the generation of gamma-ray libraries (using new, evaluated data) for specific applications; TRUE C OINC, a program to calculate true coincidence corrections; VOLUME, a program to calculate the full-energy peak efficiency calibration curve for homogeneous cylindrical sample geometries including self-attenuation correction; WINDIMEN, a program for the library driven analysis of gamma-ray spectra and for the quantification of radionuclide contents in the sample. RESFIT and DPPUNFOL, a set of programs for the definition of the detector resolution function and for unfolding of experimental annihilation spectra; MLMTEST, a program for the analysis of low-level NaI-spectra together with an extensive library of example reference spectra as well as a spectrum synthesizer

Natural radioactivity in iron and steel materials by low-level gamma spectrometry

International Nuclear Information System (INIS)

Tanase, G.; Tanase, Maria

2003-01-01

High resolution low-level gamma spectrometry was applied to perform a radioactivity measurement in iron and steel raw materials (coal, coke, iron ore, pellets, manganese ore, limestone, dolomite), auxiliary materials (scorialite, oxide of Ti, bentonite), and some related final products (cast iron, slag, blast-furnace, flue dust) involved in iron making processing. We control the activity of materials in various kinds of samples and we investigate for transfer of radioactivity during the blast-furnace process. Artificial radioisotopes are rarely encountered. (authors)

Phosphorylation of Mycobacterium tuberculosis ParB participates in regulating the ParABS chromosome segregation system.

Science.gov (United States)

Baronian, Grégory; Ginda, Katarzyna; Berry, Laurence; Cohen-Gonsaud, Martin; Zakrzewska-Czerwińska, Jolanta; Jakimowicz, Dagmara; Molle, Virginie

2015-01-01

Here, we present for the first time that Mycobacterium tuberculosis ParB is phosphorylated by several mycobacterial Ser/Thr protein kinases in vitro. ParB and ParA are the key components of bacterial chromosome segregation apparatus. ParB is a cytosolic conserved protein that binds specifically to centromere-like DNA parS sequences and interacts with ParA, a weak ATPase required for its proper localization. Mass spectrometry identified the presence of ten phosphate groups, thus indicating that ParB is phosphorylated on eight threonines, Thr32, Thr41, Thr53, Thr110, Thr195, and Thr254, Thr300, Thr303 as well as on two serines, Ser5 and Ser239. The phosphorylation sites were further substituted either by alanine to prevent phosphorylation or aspartate to mimic constitutive phosphorylation. Electrophoretic mobility shift assays revealed a drastic inhibition of DNA-binding by ParB phosphomimetic mutant compared to wild type. In addition, bacterial two-hybrid experiments showed a loss of ParA-ParB interaction with the phosphomimetic mutant, indicating that phosphorylation is regulating the recruitment of the partitioning complex. Moreover, fluorescence microscopy experiments performed in the surrogate Mycobacterium smegmatis ΔparB strain revealed that in contrast to wild type Mtb ParB, which formed subpolar foci similar to M. smegmatis ParB, phoshomimetic Mtb ParB was delocalized. Thus, our findings highlight a novel regulatory role of the different isoforms of ParB representing a molecular switch in localization and functioning of partitioning protein in Mycobacterium tuberculosis.

Phosphorylation of Mycobacterium tuberculosis ParB participates in regulating the ParABS chromosome segregation system.

Directory of Open Access Journals (Sweden)

Grégory Baronian

Full Text Available Here, we present for the first time that Mycobacterium tuberculosis ParB is phosphorylated by several mycobacterial Ser/Thr protein kinases in vitro. ParB and ParA are the key components of bacterial chromosome segregation apparatus. ParB is a cytosolic conserved protein that binds specifically to centromere-like DNA parS sequences and interacts with ParA, a weak ATPase required for its proper localization. Mass spectrometry identified the presence of ten phosphate groups, thus indicating that ParB is phosphorylated on eight threonines, Thr32, Thr41, Thr53, Thr110, Thr195, and Thr254, Thr300, Thr303 as well as on two serines, Ser5 and Ser239. The phosphorylation sites were further substituted either by alanine to prevent phosphorylation or aspartate to mimic constitutive phosphorylation. Electrophoretic mobility shift assays revealed a drastic inhibition of DNA-binding by ParB phosphomimetic mutant compared to wild type. In addition, bacterial two-hybrid experiments showed a loss of ParA-ParB interaction with the phosphomimetic mutant, indicating that phosphorylation is regulating the recruitment of the partitioning complex. Moreover, fluorescence microscopy experiments performed in the surrogate Mycobacterium smegmatis ΔparB strain revealed that in contrast to wild type Mtb ParB, which formed subpolar foci similar to M. smegmatis ParB, phoshomimetic Mtb ParB was delocalized. Thus, our findings highlight a novel regulatory role of the different isoforms of ParB representing a molecular switch in localization and functioning of partitioning protein in Mycobacterium tuberculosis.

Determination of burnup for IEAR-1 fuel elements by non destructive method of gamma spectrometry

International Nuclear Information System (INIS)

Madi Filho, T.; Holland, L.

1982-01-01

Burnup determination, by non-destructive gamma spectrometry of spent fuel with high and low activity of IEAR-1 reactor, using Cs-137 as burnup monitor, were done. To measure the Cs-137 distribution in these elements a Ge(Li) detector, with volume equal to 73,7 cm 3 , in two measurement systems with defined geometry and good colimation, was used. The IEA-14 taken from the core about 20 years ago, presents a gamma spectra due to Cs-137. The IEA-80, with cooling time approximately to 5 years, shows a more complex gamma spectrum due to other fission products still found in significant quantities. The IEA-14 measures were done in a measurement system used outside the reactor pool (S.I.), being the global efficiency of this system obtained by using a plane, calibrated and extense Ag-110 m source. Detailed measures of gamma transmission, using Cs-137 as a calibrated and punctiforme source, showed the high homogenity of the fuel plates. (E.G.) [pt

Data processing in gamma spectrometry. Application to the decay schemes study; Traitement des informations en spectrometrie gamma application a l'etude de schemas de desintegration

Energy Technology Data Exchange (ETDEWEB)

Boulanger, J.P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, departement d' electronique generale, service d' instrumentation nucleaire

1968-06-01

The purpose of this thesis is the processing of the data issued from a gamma spectrometer, and its applications to the decay schemes study. The mathematical analysis of the full energy peaks, in connection with the very good resolution of semi-conductor detectors, leads to a very accurate determination of the energies. The resolution of complex spectra by the least squares method, completed by a spectra generating process, allows the calculation of branching ratios. Then, the handling of the two dimensional experiments permits the coincidence exam. For each of these methods, the calculation principle, then the systematics tests realized in order to prove their validity and to determine their application ranges as well as some experimental results appropriate to illustrate their possibilities, are presented. The energies of some nuclides, frequently used as standards have been thus measured and the decay schemes of {sup 134}Cs and {sup 110m}Ag determined precisely. (author) [French] Cette these est consacree aux methodes de traitement des informations issues d'un spectrometre {gamma}, et a leur application a l'etude des schemas de desintegration: l'analyse mathematique des pics d'absorption totale, conjuguee avec l'excellent pouvoir de resolution des detecteurs semi-conducteurs, conduit a une determination tres precise des energies. La decomposition des spectres complexes par la methode des moindres carres, completee par un procede de generation de spectres, autorise le calcul des rapports de branchement. Enfin le depouillement des experiences biparametriques permet l'examen des coincidences. Pour chacune de ces methodes, on expose le principe des calculs et les essais systematiques effectues afin d'eprouver leur validite et de definir leurs domaines d'application, ainsi que quelques resultats experimentaux propres a illustrer leurs possibilites. Les energies de quelques isotopes utilises couramment comme etalons ont ainsi ete

Characterization of Uranium-Bearing Material by Passive Non-Destructive Gamma Spectrometry

International Nuclear Information System (INIS)

Lakosi, L.; Zsigrai, J.; Nguyen, C.T.

2009-01-01

Characterization of nuclear materials is equally important in nuclear safeguards (inventory verification) and in nuclear security (revealing illicit trafficking). Analysis of materials is a key issue in both fields. Natural (NU), depleted (DU), low-enriched (LEU), and high-enriched uranium (HEU) samples were analysed by high resolution gamma spectrometry (HRGS). Isotopic composition and total U-content of reactor fuel pellets and powder were determined. A unique HRGS method was developed for the first time for determining the production date of the material of unknown origin. Identifying reprocessed uranium proved to be possible by HRGS as well.

An intercomparison of Monte Carlo codes used for in-situ gamma-ray spectrometry

International Nuclear Information System (INIS)

Hurtado, S.; Villa, M.

2010-01-01

In-situ gamma-ray spectrometry is widely used for monitoring of natural as well as man-made radionuclides and corresponding gamma fields in the environment or working places. It finds effective application in the operational and accidental monitoring of nuclear facilities and their vicinity, waste depositories, radioactive contamination measurements and environmental mapping or geological prospecting. In order to determine accurate radionuclide concentrations in these research fields, Monte Carlo codes have recently been used to obtain the efficiency calibration of in-situ gamma-ray detectors. This work presents an inter-comparison between two Monte Carlo codes applied to in-situ gamma-ray spectrometry. On the commercial market, Canberra has its LABSOCS/ISOCS software which is relatively inexpensive. The ISOCS mathematical efficiency calibration software uses a combination of Monte Carlo calculations and discrete ordinate attenuation computations. Efficiencies can be generated in a few minutes in the field and can be modified easily if needed. However, it has been reported in the literature that ISOCS computation method is accurate on average only within 5%, and additionally in order to use LABSOCS/ISOCS it is necessary a previous characterization of the detector by Canberra, which is an expensive process. On the other hand, the multipurpose and open source GEANT4 takes significant computer time and presents a non-friendly but powerful toolkit, independent of the manufacturer of the detector. Different experimental measurements of calibrated sources were performed with a Canberra portable HPGe detector and compared to the results obtained using both Monte Carlo codes. Furthermore, a variety of efficiency calibrations for different radioactive source distributions were calculated and tested, like plane shapes or containers filled with different materials such as soil, water, etc. LabSOCS simulated efficiencies for medium and high energies were given within an

Low-energy X-ray and gamma spectrometry using silicon photodiodes

International Nuclear Information System (INIS)

Silva, Iran Jose Oliveira da

2000-08-01

The use of semiconductor detectors for radiation detection has increased in recent years due to advantages they present in comparison to other types of detectors. As the working principle of commercially available photodiodes is similar to the semiconductor detector, this study was carried out to evaluate the use of Si photodiodes for low energy x-ray and gamma spectrometry. The photodiodes investigated were SFH-205, SFH-206, BPW-34 and XRA-50 which have the following characteristics: active area of 0,07 cm 2 and 0,25 cm 2 , thickness of the depletion ranging from 100 to 200 μm and junction capacitance of 72 pF. The photodiode was polarized with a reverse bias and connected to a charge sensitive pre-amplifier, followed by a amplifier and multichannel pulse analyzer. Standard radiation source used in this experiment were 241 Am, 109 Cd, 57 Co and 133 Ba. The X-ray fluorescence of lead and silver were also measured through K- and L-lines. All the measurements were made with the photodiodes at room temperature.The results show that the responses of the photodiodes very linear by the x-ray energy and that the energy resolution in FWHM varied between 1.9 keV and 4.4 keV for peaks corresponding to 11.9 keV to 59 keV. The BPW-34 showed the best energy resolution and the lower dark current. The full-energy peak efficiency was also determined and it was observed that the peak efficiency decreases rapidly above 50 keV. The resolution and efficiency are similar to the values obtained with other semiconductor detectors, evidencing that the photodiodes used in that study can be used as a good performance detector for low energy X-ray and gamma spectrometry. (author)

The determination of iodine in biological media using radioactivation analysis (1962); Dosage de l'iode dans les milieux biologiques au moyen de l'analyse par radioactivation (1962)

Energy Technology Data Exchange (ETDEWEB)

Comar, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-06-15

The object of this study is to show that the application of radioactivation analysis to the determination of iodine in biological media makes it possible to measure iodine concentrations of the order of 0.0001 {mu}g. After a review of the chemical methods with a mention of the difficulties they present, the optimum conditions for the determination of iodine in biological liquids are given. Three methods are described: - the first consists of a chemical treatment which liberates the protein bound iodine in an inorganic form. After distillation this iodine is irradiated in a flux of thermal neutrons. The induced radioactivity is compared to that of a standard sample irradiated in the same conditions by {gamma} spectrometry. - the second method which is of more general application consists in irradiating the sample and then extracting the iodine; its induced radio-activity is then measured by {beta}-counting. - the third method measures the iodine directly in the thyroid tissue by anti-compton spectrometry. The sensitivity, the reproducibility and the accuracy are discussed. Some applications are described: determination of iodine in its various organic forms in serum, determination of iodine in urines, in food-stuffs, etc., in the thyroid tissue, etc. (author) [French] Le but de cette etude est de montrer que l'analyse par radioactivation appliquee au dosage de l'iode dans les milieux biologiques permet de mesurer des taux d'iode de l'ordie de 0,0001 {mu}g. Apres avoir rappele le principe des methodes chimiques et montre les difficultes de leur mise en oeuvre, il est etabli les conditions optima pour realiser le dosage de l'iode dans les liquides biologiques. Trois methodes sont decrites; - la premiere consiste a pratiquer un traitement chimique liberant l'iode proteique sous forme minerale. Apres distillation cet iode est irradie dans un flux de neutrons thermiques. La radioactivite induite est mesuree comparativement a celle d'un etalon traite dans les memes

Composite mapping experiences in airborne gamma spectrometry.

Science.gov (United States)

Bucher, B

2014-08-01

During an international intercomparison exercise of airborne gamma spectrometry held in Switzerland 2007 teams from Germany, France and Switzerland were proving their capabilities. One of the tasks was the composite mapping of an area around Basel. Each team was mainly covering the part of its own country at its own flying procedures. They delivered the evaluated data in a data format agreed in advance. The quantities to be delivered were also defined in advance. Nevertheless, during the process to put the data together a few questions raised: Which dose rate was meant? Had the dose rate to be delivered with or without cosmic contribution? Activity per dry or wet mass? Which coordinate system was used? Finally, the data could be put together in one map. For working procedures in case of an emergency, quantities of interest and exchange data format have to be defined in advance. But the procedures have also to be proved regularly. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Gamma spectrometry today

International Nuclear Information System (INIS)

Hemingway, J.

1990-01-01

This paper reviews the important advances in gamma spectroscopy made in recent years. Improvements in detectors and other components and the addition of on-line computer control systems is discussed. (UK)

Study of transformations by annealing of the body. Centred cubic {gamma} phase of uranium-molybdenum alloys; Etude des transformations par revenu de la phase {gamma} cubique centree des alliages uranium-molybdene

Energy Technology Data Exchange (ETDEWEB)

Mikailoff, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1959-06-15

By annealing at different temperatures, we have studied the transformations of the body centred cubic {gamma} phase for two alloys containing 6 and 10 per cent molybdenum by weight respectively. There is a return to the equilibrium state by formation of the stable {alpha} orthorhombic and {epsilon} ordered tetragonal phases, following two types of reaction: - pearlite transformation by nucleation and growth from the grain boundaries, preponderant when the annealing takes place at temperature above 400 deg. C, and identical for the two types of alloys. This reaction has already been studied by numerous authors, who have constructed the corresponding TTT curves, - transformation inside the grains of the quenched solid solution when annealing takes place at 400 deg. C or below: 6 per cent alloy - precipitation of fine a phase particles, followed by progressive ordering of the solid solution enriched in molybdenum, 10 per cent alloy - formation of small ordered regions and then a fine a phase precipitate. In the course of this work we have paid particular attention to the study of intragranular reactions after low-temperature annealing, the reactions involved in this case not having been explained up to the present. The {gamma} phase transformation has been studied by means of three techniques: micrography - microhardness tests - X-ray diffraction. (author) [French] Nous avons etudie les transformations par revenu a differentes temperatures, de la phase {gamma} cubique centree des alliages U-Mo trempes, pour deux alliages a 6 et a 10 pour cent de molybdene en poids. Il y a retour a l'etat d'equilibre par formation des phases stables {alpha} orthorhombique et quadratique ordonnee, suivant deux types de reactions: - transformation perlitique par germination et croissance a partir des joints de grains, preponderante lorsque le recuit a lieu a temperature superieure a 400 deg. C, et identique pour les deux types d'alliages. Cette reaction a deja ete etudiee par de nombreux

Shaly sand evaluation using gamma ray spectrometry, applied to the North Sea Jurassic

International Nuclear Information System (INIS)

Marett, G.; Chevalier, P.; Souhaite, P.; Suau, J.

1976-01-01

In formations where radioactive minerals other than clay are present, their effects on log responses result in a reduction of the accuracy of determination of the shale fraction. The gamma ray log, which is one of the primary indicators for shaliness determination, is the most affected; other logs used in shaliness indicators are also influenced, particularly when heavy minerals are present, such as those encountered in the micaceous sandstones of the North Sea Jurassic. For comparison purposes, possible ways to correct for heavy radioactive minerals using a conventional logging suite are described. Computer processed examples illustrate the results obtained. A different approach is through an analysis of the natural gamma ray spectrum of the formation, as determined with the gamma ray spectrometry tool. Natural gamma rays originate from the radioactive isotope of potassium and the radioactive elements of the uranium and thorium series. Each of these three elements contributes its distinctive spectrum to that of the formation in proportion to its abundance. Thus, by analysis of the formation spectrum, the presence of each can be detected and its amount estimated. This makes possible quantitative corrections to the shaliness indicators. A computer program which performs the necessary computations is described, and several log examples using this technique are presented

Gamma spectrometry for chronology of recent sediments

International Nuclear Information System (INIS)

Pittauerova, Daniela

2013-01-01

This thesis deals with several aspects of gamma spectrometric analysis of natural and artificial isotopes in sediments and their use as tracers for qualification and quantification of accumulation and mixing processes in different aquatic environments. Sediment cores from three distinct areas including terrigenous sediments deposited on the continental slope off NW Africa, deep sea sediments off Sumba Island and five stations from the Gulf of Eilat in the Red Sea area were measured and interpreted within this dissertation. The main concern in gamma spectrometry of voluminous environmental samples is a reliable efficiency calibration. This is specially relevant for the analysis of low energy gamma emitters (<100 keV). 210 Pb, an important isotopic tracer to cover the period of the last century, is one of them. Within this work mathematical efficiency calibration was applied using a commercial software package. A series of validation tests was performed and evaluated for point and voluminous samples. When using 210 Pb as a tracer it is necessary to determine its excess portion, which is not supported by ingrowth from the parent nuclide 226 Ra. Its analysis is mostly performed via short lived daughter isotopes that follow after the intermediate gaseous member 222 Rn. Preventing the escape of radon from the sample is a critical step before analysis due to a negative effect of supported 210 Pb underestimation on the chronology, which was also documented in this thesis. Time series registering ingrowth of 214 Pb and 214 Bi towards radioactive equilibrium with 226 Ra in different containers were evaluated for analyses of 226 Ra. Direct analyses of 226 Ra was compared to its detection via daughter products. A method for aligning parallel radionuclide depth profiles was described and applied successfully in two case studies from the continental slope off NW Africa and off Sumba Island, Indonesia. This is primarily important when combined profiles obtained from short

Uranium Enrichment Determination of the InSTEC Sub Critical Ensemble Fuel by Gamma Spectrometry

International Nuclear Information System (INIS)

Borrell Munnoz, Jose L.; LopezPino, Neivy; Diaz Rizo, Oscar; D'Alessandro Rodriguez, Katia; Padilla Cabal, Fatima; Arbelo Penna, Yunieski; Garcia Rios, Aczel R.; Quintas Munn, Ernesto L.; Casanova Diaz, Amaya O.

2009-01-01

Low background gamma spectrometry was applied to analyze the uranium enrichment of the nuclear fuel used in the InSTEC Sub Critical ensemble. The enrichment was calculated by two variants: an absolute method using the Monte Carlo method to simulated detector volumetric efficiency, and an iterative procedure without using standard sources. The results confirm that the nuclear fuel of the ensemble is natural uranium without any additional degree of enrichment. (author)

Measurement of natural gamma radiation in building materials from Thellar of Tiruvannamalai Dist, Tamilnadu, India by gamma ray spectrometry

International Nuclear Information System (INIS)

Raghu, Y.; Ravisankar, R.; Chandrasekararn, A.; Vijayagopal, P.; Venkatraman, B.

2016-01-01

The knowledge of natural radioactivity in building materials is an important aspect of or determining the amount of public exposure because people spend most of their time (about 80%) indoors. Further, the knowledge of this radioactivity is useful in setting the standards and national guidelines in regard to the international recommendations and in assessing the associated radiation hazard. In the present work, the concentrations of natural radionuclides were measured in four types of building materials from Thellar of Tiruvannamalai district, Tamilnadu, India using gamma-ray spectrometry and associated radiological hazards are calculated

Determination of 226Ra by gamma spectrometry: study of packaging vial of sample for analysis

International Nuclear Information System (INIS)

Carneiro, Andre Cavalcanti

2015-01-01

Determination of radioactivity levels of 226 Ra by gamma spectrometry in a sample is based on measurements of 214 Pb and 214 Bi, daughters of 222 Rn. Because radon is a gas, it can leak from the sample vial or accumulate on the upper empty it. If the vial has any crack, there will be loss of gas, which will cause error in determining the 226 Ra concentration. One possible cause of cracks in the vials, that houses standards and samples, is the radiolysis action in the vial material, usually a polymer. As the demand 226 Ra analysis in different matrices (geological samples, food, plants, etc.) is increasing, it was decided to study some polymer vials available on the market, to verify the feasibility to be used when is applied the analysis method using gamma spectrometry. Four types of polymer vials have been studied. The radiation doses in walls of the vials caused by natural radionuclides present in the sample were simulated using gamma irradiation. Tests, such as compressive strength test and tightness, were applied to the irradiated and non-irradiated vials. First, to verify the effect of radiolysis on the vial material and also if there was 222 Rn diffusion in their walls. These preliminary results pointed out that the acrylic vials are the best option of packaging samples for analysis. This study should be repeated in a larger number of samples for a better evaluation. (author)

The activity of {gamma}-emitters as measured by ionisation chambers the determination of the specific emission coefficient {gamma} for some radio-elements (1961); Mesure de l'activite des emetteurs {gamma} par chambre d'ionisation. Determination du coefficient specifique d'emission {gamma} de quelques radioelements (1961)

Energy Technology Data Exchange (ETDEWEB)

Engelmann, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-06-15

The object of this work is to study techniques of measurement using the gamma ionisation chamber, making it possible either to measure the activities of radioactive sources, or to determine the specific emission coefficient {gamma} (or the coefficient K) of a given radioelement. The ionisation chambers studied belong to two categories: graphites cavity-chambers, and 4 {pi} {gamma} chambers. For the cavity-chamber measurements, the different correction factors of which account must be taken have been calculated, in particular the geometric and hygrometric corrections. The absorption and auto-absorption corrections have led to the introduction of the notion of the 'effective energy {gamma}' of a radioelement. In the case of 4 {pi} {gamma} chambers, it has been shown that appropriately shaped electrodes make it possible to improve their performances. One of the chambers described permits the measurement of {beta} emitters using the associated Bremsstrahlung. In order to measure the K coefficient of some radioelements, it has been found useful a 4 {pi} {gamma} chamber with graphite walls, the measurement being carried out by comparison with a radium standard. The validity of the method was checked with radioelements for whom the K coefficient values are well-known ({sup 24}Na, {sup 60}Co, {sup 131}I, {sup 198}Au). For other radioelements, the following values were obtained (expressed in r cm{sup 3} mc{sup -1} h{sup -1}): {sup 51}Cr: 0,18; {sup 56}Mn: 8,8; {sup 65}Zn: 3,05; {sup 124}Sb: 9,9; {sup 134}Cs: 9,3; {sup 137}Cs: 3,35; {sup 141}Ce: 0,46; {sup 170}Tm: 0,023; {sup 192}Ir: 24,9; {sup 203}Hg: 1,18; These values have been corrected for the contribution to the dose of the fluorescent radiation which may be emitted by the source, except in the case of Tm{sup 170}. In the last part of this work, the performances of the different electro-metric devices used were compared. (author) [French] Le but de ce travail est d'etudier les techniques de mesure par

Comparison of in-situ gamma ray spectrometry measurements with conventional methods in determination natural and artificial nuclides in soil

International Nuclear Information System (INIS)

Al-Masri, M. S.; Doubal, A. W.

2010-12-01

Two nuclear analytical techniques (In-Situ Gamma ray spectrometry and laboratory gamma ray spectrometry) for determination of natural and artificial radionuclides in soil have been validated. The first technique depends on determination of radioactivity content of representative samples of the studied soil after laboratory preparation, while the second technique is based on direct determination of radioactivity content of soil using in-situ gamma-ray spectrometer. Analytical validation parameter such as detection limits, repeatability, reproducibility in addition to measurement uncertainties were estimated and compared for both techniques. Comparison results have shown that the determination of radioactivity in soil should apply the two techniques together where each of techniques is characterized by its low detection limit and uncertainty suitable for defined application of measurement. Radioactive isotopes in various locations were determined using the two methods by measuring 40 k, 238 U,and 137 Cs. The results showed that there are differences in attenuation factors due to soil moisture content differences; wet weight corrections should be applied when the two techniques are compared. (author)

Nuclear energy. Waste-packages activity measurement. Part. 1: high-resolution gamma spectrometry in integral mode with open geometry; ISO 14850-1: 2004. Energie nucleaire -- Mesurage de l'activite de colis de dechets. Partie 1: Spectrometrie gamma haute resolution en mode integral et geometrie ouverte

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

ISO 14850:2004 describes a procedure for measurements of gamma-emitting radionuclide activity in homogeneous objects such as unconditioned waste (including process waste, dismantling waste, etc.), waste conditioned in various matrices (bitumen, hydraulic binder, thermosetting resins, etc.), notably in the form of 100 L, 200 L, 400 L or 800 L drums, and test specimens or samples, (vitrified waste), and waste packaged in a container, notably technological waste. It also specifies the calibration of the gamma spectrometry chain. The gamma energies used generally range from 0,05 MeV to 3 MeV.

Nuclear energy - Waste-packages activity measurement - Part.1: high-resolution gamma spectrometry in integral mode with open geometry; ISO 14850-1:2004. Energie nucleaire - Mesurage de l'activite de colis de dechets - Partie 1: spectrometrie gamma haute resolution en mode integral et geometrie ouverte

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

ISO 14850:2004 describes a procedure for measurements of gamma-emitting radionuclide activity in homogeneous objects such as unconditioned waste (including process waste, dismantling waste, etc.), waste conditioned in various matrices (bitumen, hydraulic binder, thermosetting resins, etc.), notably in the form of 100 L, 200 L, 400 L or 800 L drums, and test specimens or samples, (vitrified waste), and waste packaged in a container, notably technological waste. It also specifies the calibration of the gamma spectrometry chain. The gamma energies used generally range from 0,05 MeV to 3 MeV. (authors)

Radon gamma-ray spectrometry with YAP:Ce scintillator

CERN Document Server

Plastino, W; De Notaristefani, F

2002-01-01

The detection properties of a YAP:Ce scintillator (YAlO sub 3 :Ce crystal) optically coupled to a Hamamatsu H5784 photomultiplier with standard bialkali photocathode have been analyzed. In particular, the application to radon and radon-daughters gamma-ray spectrometry was investigated. The crystal response has been studied under severe extreme conditions to simulate environments of geophysical interest, particularly those found in geothermal and volcanic areas. Tests in water up to a temperature of 100 deg.C and in acids solutions such as HCl (37%), H sub 2 SO sub 4 (48%) and HNO sub 3 (65%) have been performed. The measurements with standard radon sources provided by the National Institute for Metrology of Ionizing Radiations (ENEA) have emphasized the non-hygroscopic properties of the scintillator and a small dependence of the light yield on temperature and HNO sub 3. The data collected in this first step of our research have pointed out that the YAP:Ce scintillator can allow high response stability for rad...

Characterization of radioactive orphan sources by gamma spectrometry

International Nuclear Information System (INIS)

Cruz W, H.

2013-01-01

The sealed radioactive sources are widely applicable in industry. They must have a permanent control and must be registered with the Technical Office of the National Authority (OTAN). However, at times it has identified the presence of abandoned sealed sources unknown to the owner. These sources are called 'orphan sources'. Of course these sources represent a high potential risk because accidents can trigger dire consequences depending on your activity and chemical form in which it presents the radioisotope. This paper describes the process and the actions taken to characterize two orphan radioactive sources from the smelter a Aceros Arequipa. For characterization we used a gamma spectrometry system using a detector NaI(Tl) 3″ x 3″ with a multichannel analyzer Nucleus PCA-II. The radioisotope identified was cesium - 137 ( 137 Cs) in both cases. Fortunately, the sources maintained their integrity would otherwise have generated significant pollution considering the chemical form of the radioisotope and easy dispersion. (author)

Determination of Pu isotopic composition and 241Am by high resolution gamma spectrometry on solid samples

International Nuclear Information System (INIS)

Sarkar, Arnab; Paul, Sumana; Aggarwal, Suresh K.; Tomar, Bhupendra S.

2011-08-01

The present report gives a detailed account of the development of non-destructive assay technique using high resolution gamma-ray spectrometry (HRGS) for determination of plutonium (Pu) isotopic composition and the 241 Am content in solid Pu samples. Energy range 120-420 keV was used in this study. The methodology involves in situ relative efficiency calibration during the measurement process itself, to reduce the errors and increase the reliability of the method. Twenty solid Pu samples of power reactor and research reactor grade were analyzed by this method and the results were compared with those obtained by thermal ionization mass spectrometry. The accuracy of the final results depends strongly upon the accuracy of the available nuclear data (decay constant, gamma abundance etc.). MATLAB based programme was written to perform the analysis. A counting time of 4 hour was chosen for achieving good statistics on the results for samples having 100-200 mg of Pu. The attainable accuracy is found to be 0.5-1% for the fissile isotopes ( 239 Pu + 241 Pu) and 5-10% for 241 Am content. (author)

Airborne gamma-ray spectrometry

DEFF Research Database (Denmark)

Hovgaard, Jens

A new method - Noise Adjusted Singular Value Decomposition, NASVD - for processing gamma-ray spectra has been developed as part of a Ph.D. project. By using this technique one is able to decompose a large set of data - for example from airborne gamma-ray surveys - into a few spectral components....... By knowing the spectral components and their amplitudes in each of the measured spectra one is able to extract more information from the data than possible with the methods used otherwise....

Gamma spectrometry and chemical characterization of bioactive glass seeds with Holmium-166 for oncological implants

International Nuclear Information System (INIS)

Valente, Eduardo S.

2009-01-01

Bioactive glass seeds synthesized by the sol-gel technique with Si:Ho:Ca composition with natural holmium incorporated were irradiated in the TRIGA type nuclear reactor IPR-R1 at 100kW, in the central thimble where the thermal neutron flux is 2.8x10 12 n/cm 2 .s and the epithermal neutron flux is 2.6 X 10 11 n/cm 2 .s . After an 8 hour irradiation time, with an induced activity close to 110MBq/seed, a set of seeds was submitted to Gamma Spectrometry Analysis in a counting system with an HPGe detector, ORTEC electronic instrumentation and a Camberra Multichannel Analyser, to determine all radionuclides present on the sample as well as its individual activities. Special attention was paid on the discrimination of Si, 40 Ca, 44 Ca, C and Ho as the other expected elements like 48 Ca, 2 H and 18 O were present in traces or have very short half-lives. The second sample was submitted to Plasma spectrometry to determine the 166 Ho concentration in weight. The third sample was submitted to an X-ray spectrometry in a JEOL-JXA-8900RL equipment to determine its qualitative chemical composition, in order to evaluate impurities and nominal composition. It was determined that most of the activity, after decaying of short half-life elements, was due to 166 Ho present on the sample, with a well characterized β and gamma spectra. The homogeneity of the seeds was tested on the X-ray spectrometry, and verified that there is no discrepancy in composition from distinct seeds or in a same seed. The results are relevant on the investigation of the viability of producing 166 Ho radioactive seeds for oncological implants. (author)

Dating the age of a recent nuclear event by gamma-spectrometry

International Nuclear Information System (INIS)

Nir-El, Y.

2006-01-01

The age of a recent, i.e., fresh, nuclear event can be determined by measuring the activity of short-lived parent and daughter fission products. The event studied was a short irradiation, of a small sample of uranium, in a nuclear reactor. Two clocks were investigated, 92 Sr- 92 Y and 135 I- 135 Xe. Measurements of the source by gamma-spectrometry yielded very good agreement between true and measured ages. The upper and lower age limits of applicability for the clocks in question were defined. The half-life of 92 Sr was found 2.635±0.008 hours and of 135 I 6.65±0.04 hours. (author)

Overview of gamma spectrometry measurement devices developed by ENVINET a.s

International Nuclear Information System (INIS)

Sidlova, V.; Slama, L.; Holecek, V.; Chaloupkova, H.

2008-01-01

This paper demonstrates the development and usage of the devices designed for non- destructive radiological characterization of radioactive waste. All ..systems are based on gamma-spectrometry and are divided into two categories - stable and mobile. Stable ones involve only measurement in fixed detector - package configuration. They are used for assessment of packaged waste, mainly in drums. Mobile ones are flexible and allow measurement of a wide range of objects from various positions and can be also transported to arbitrary location. The calibration of such systems is performed by means of appropriate software which allows computation of full-energy peak efficiency in various configurations. (authors)

Burn-up measurements coupling gamma spectrometry and neutron measurement

Energy Technology Data Exchange (ETDEWEB)

Toubon, H.; Pin, P. [AREVA/CANBERRA, 1 rue des Herons, 78182 St Quentin-en-Yvelines Cedex (France); Lebrun, A. [IAEA, Wagramer Strasse 5, PO Box 100, Vienna (Austria); Oriol, L.; Saurel, N. [CEA Cadarache, 13108 Saint Paul Lez Durance Cedex (France); Gain, T. [AREVA/COGEMA Reprocessing Business Unit, La Hague, 50444 Beaumont Hague Cedex (France)

2006-07-01

The need to apply for burn-up credit arises with the increase of the initial enrichment of nuclear fuel. When burn-up credit is used in criticality safety studies, it is often necessary to confirm it by measurement. For the last 10 years, CANBERRA has manufactured the PYTHON system for such measurements. However, the method used in the PYTHON itself uses certain reactor data to arrive at burn-up estimates. Based on R and D led by CEA and COGEMA in the framework of burn-up measurement for burn-up credit and safeguards applications, CANBERRA is developing the next generation of burn-up measurement device. This new product, named SMOPY, is able to measure burn-up of any kind of irradiated fuel assembly with a combination of gamma spectrometry and passive neutron measurements. The measurement data is used as input to the CESAR depletion code, which has been developed and qualified by CEA and COGEMA for burn-up credit determinations. In this paper, we explain the complementary nature of the gamma and neutron measurements. In addition, we draw on our previous experience from PYTHON system and from COGEMA La Hague to show what types of evaluations are required to qualify the SMOPY system, to estimate its uncertainties, and to detect discrepancies in the fuel data given by the reactor plant to characterize the irradiated fuel assembly. (authors)

Burn-up measurements coupling gamma spectrometry and neutron measurement

International Nuclear Information System (INIS)

Toubon, H.; Pin, P.; Lebrun, A.; Oriol, L.; Saurel, N.; Gain, T.

2006-01-01

The need to apply for burn-up credit arises with the increase of the initial enrichment of nuclear fuel. When burn-up credit is used in criticality safety studies, it is often necessary to confirm it by measurement. For the last 10 years, CANBERRA has manufactured the PYTHON system for such measurements. However, the method used in the PYTHON itself uses certain reactor data to arrive at burn-up estimates. Based on R and D led by CEA and COGEMA in the framework of burn-up measurement for burn-up credit and safeguards applications, CANBERRA is developing the next generation of burn-up measurement device. This new product, named SMOPY, is able to measure burn-up of any kind of irradiated fuel assembly with a combination of gamma spectrometry and passive neutron measurements. The measurement data is used as input to the CESAR depletion code, which has been developed and qualified by CEA and COGEMA for burn-up credit determinations. In this paper, we explain the complementary nature of the gamma and neutron measurements. In addition, we draw on our previous experience from PYTHON system and from COGEMA La Hague to show what types of evaluations are required to qualify the SMOPY system, to estimate its uncertainties, and to detect discrepancies in the fuel data given by the reactor plant to characterize the irradiated fuel assembly. (authors)

Standard test method for quantitative determination of americium 241 in plutonium by Gamma-Ray spectrometry

CERN Document Server

American Society for Testing and Materials. Philadelphia

1994-01-01

1.1 This test method covers the quantitative determination of americium 241 by gamma-ray spectrometry in plutonium nitrate solution samples that do not contain significant amounts of radioactive fission products or other high specific activity gamma-ray emitters. 1.2 This test method can be used to determine the americium 241 in samples of plutonium metal, oxide and other solid forms, when the solid is appropriately sampled and dissolved. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Design of an automatic sample changer for the measurement of neutron flux by gamma spectrometry

International Nuclear Information System (INIS)

Gago, Javier; Bruna, Ruben; Baltuano, Oscar; Montoya, Eduardo; Descreaux, Killian

2014-01-01

This paper presents calculus, selection and components design for the construction of an automatic system in order to measure neutron flux in a working nuclear reactor by the gamma spectrometry technique using samples irradiated on the RP-10 nucleus. This system will perform the measurement of interchanging 100 samples in a programed and automatic way, reducing operation time by the user and obtaining more accurate measures. (authors).

Methodology for determination of activity of radionuclides by gamma spectrometry; Metodologia para determinacao da atividade de radionuclideos por sistema de espectrometria gama

Energy Technology Data Exchange (ETDEWEB)

Fragoso, Maria da Conceicao de Farias; Oliveira, Victor Rogerio S. de; Oliveira, Mercia L.; Lima, Fernando Roberto de Andrade, E-mail: mariacc05@gmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-NE), Recife, PE (Brazil)

2014-07-01

Due to the growth in the number of procedures that make use of the positron emission tomography (PET), there is a need for standard solutions for the calibration of the systems used for the measurement of the PET radiopharmaceutical (activimeter) in radiopharmacies and in nuclear medicine services. Among the existing alternatives for the standardization of radioactive sources, the method known as gamma spectrometry is widely used for short-lived radionuclides. The purpose of this study was to implement the methodology for standardization of the {sup 18}F solutions by gamma spectrometry at the Regional Center for Nuclear Sciences of the Northeast (CRCN-NE/CNEN-NE), Brazil. (author)

Application of simulated standard spectra in natural radioactivity measurements using gamma spectrometry

International Nuclear Information System (INIS)

Narayani, K.; Pant, A.D.; Bhosle, Nitin; Anilkumar, S.; Singh, Rajvir; Pradeepkumar, K.S.

2014-01-01

Gamma ray spectrometry is one of the well known analytical techniques for environmental radioactivity measurements. Gamma spectrometer based on NaI(Tl) scintillation detectors is very popular since it offers high efficiency, low cost and case in handling. The poor energy resolution of the NaI(TI) detector is the major disadvantage making tile analysis of complex gamma ray spectra difficult. Least square method or the full spectrum analysis method is widely used for the analysis of complex spectra from scintillation detectors. The main requirement of this method is that the individual standard spectra of all nuclides expected in the complex spectrum in the same measurement geometry must be available. It is not always possible and feasible to have all the standards of nuclides in the desired geometry. A methodology based on the use of simulated standard spectra generated by Monte Carlo technique was proposed for analysis of complex spectra of nuclides. In the present work, for the analysis of 238 U, 233 Th and 40 K in soil samples, the same methodology was applied by using the simulated standard spectra in soil matrix. The details of the simulation method and results analysis of 238 U, 232 Th and 40 K in environmental samples are discussed in this paper

GammaWorkshops Proceedings

International Nuclear Information System (INIS)

Ramebaeck, H.; Straelberg, E.; Klemola, S.; Nielsen, Sven P.; Palsson, S.E.

2012-01-01

Due to a sparse interaction during the last years between practioners in gamma ray spectrometry in the Nordic countries, a NKS activity was started in 2009. This GammaSem was focused on seminars relevant to gamma spectrometry. A follow up seminar was held in 2010. As an outcome of these activities it was suggested that the 2011 meeting should be focused on practical issues, e.g. different corrections needed in gamma spectrometric measurements. This three day's meeting, GammaWorkshops, was held in September at Risoe-DTU. Experts on different topics relevant for gamma spectrometric measurements were invited to the GammaWorkshops. The topics included efficiency transfer, true coincidence summing corrections, self-attenuation corrections, measurement of natural radionuclides (natural decay series), combined measurement uncertainty calculations, and detection limits. These topics covered both lectures and practical sessions. The practical sessions included demonstrations of tools for e.g. corrections and calculations of the above meantioned topics. (Author)

GammaWorkshops Proceedings

Energy Technology Data Exchange (ETDEWEB)

Ramebaeck, H. (ed.) (Swedish Defence Research Agency (Sweden)); Straalberg, E. (Institute for Energy Technology, Kjeller (Norway)); Klemola, S. (Radiation and Nuclear Safety Authority, STUK (Finland)); Nielsen, Sven P. (Technical Univ. of Denmark. Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Palsson, S.E. (Icelandic Radiation Safety Authority (Iceland))

2012-01-15

Due to a sparse interaction during the last years between practioners in gamma ray spectrometry in the Nordic countries, a NKS activity was started in 2009. This GammaSem was focused on seminars relevant to gamma spectrometry. A follow up seminar was held in 2010. As an outcome of these activities it was suggested that the 2011 meeting should be focused on practical issues, e.g. different corrections needed in gamma spectrometric measurements. This three day's meeting, GammaWorkshops, was held in September at Risoe-DTU. Experts on different topics relevant for gamma spectrometric measurements were invited to the GammaWorkshops. The topics included efficiency transfer, true coincidence summing corrections, self-attenuation corrections, measurement of natural radionuclides (natural decay series), combined measurement uncertainty calculations, and detection limits. These topics covered both lectures and practical sessions. The practical sessions included demonstrations of tools for e.g. corrections and calculations of the above meantioned topics. (Author)

Orientational relationships between phases in the {gamma}{yields}{alpha} transformations for uranium-molybdenum alloys; Relations d'orientation entre phases dans les transformations {gamma}{yields}{alpha} des alliages uranium-molybdene

Energy Technology Data Exchange (ETDEWEB)

Brun, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-04-01

A crystallographic study has been made of the {gamma} {yields} {alpha} + {gamma} transformation in the alloy containing 3 per cent by weight of molybdenum using electronic micro-diffraction; it has been possible to establish the orientational relationships governing the germination of the {alpha} phase in the {gamma} phase. One finds: (111){gamma} // (100) {alpha}, (112-bar){gamma} // (010) {alpha}, (11-bar 0){gamma} // (001){alpha}. By choosing a monoclinic lattice containing the same number of atoms as the orthorhombic lattice for defining the {gamma} mother phase, the change in structure has been explained by adding a homogeneous (112-bar){gamma} [111]{gamma} shearing deformation to a heterogeneous deformation brought about by slipping of the atoms which are not situated at the nodes of this lattice. The identity of the orientation relationships {gamma}/{alpha} and {gamma}/{alpha}''b and the loss of coherence {gamma} /{alpha} as a function of temperature or of time lead to the conclusion that, in the range studied, the {gamma} {yields} {alpha} transformation begins with a martensitic process and continues by germination and growth. (author) [French] Une etude cristallographique de la transformation {gamma} {yields} {alpha} + {gamma} dans l'alliage {alpha} 3 pour cent en poids de Mo, effectuee par microdiffraction electronique a permis d'etablir les relations d'orientation regissant la germination de {alpha} dans {gamma}. On a: (111){gamma} // (100){alpha}, (112-bar){gamma} // (010){alpha}, (11-bar 0){gamma} // (001){alpha}. En choisissant pour decrire la phase mere {gamma} une maille monoclinique contenant le meme nombre d'atomes que la maille orthorhombique {alpha}, le changement de structure a ete explique en superposant a une deformation homogene par cisaillement (112-bar){gamma} [111]{gamma} une deformation heterogene par glissement des atomes non situes aux noeuds de cette maille. L identite des relations d'orientation {gamma}/{alpha} et {gamma} /{alpha

Comparison of the analytical methods used to determine natural and artificial radionuclides from environmental samples by gamma, alpha and beta spectrometry

DEFF Research Database (Denmark)

Pöllänen, Roy; Virtanen, Sinikka; Kämäräinen, Meerit

In CAMNAR, an extensive interlaboratory exercise on the analytical methods used to determine several radionuclides present in the environmental samples was organized. Activity concentration of different natural radionuclides, such as Rn-222, Pb-210, Po-210, K-40, Ra-226, Ra-228 and isotopes...... of uranium, in addition to artificial Cs-137 and Am-241 were analysed from lake sediment samples and drinking water. The measurement techniques were gamma-ray spectrometry, alpha spectrometry, liquid scintillation counting and inductively coupled plasma mass spectrometry. Twenty six laboratories from nine...

Determination of Th and U by neutron activation for gamma spectrometry calibration in situ

International Nuclear Information System (INIS)

Nava M, F.; Rios M, C.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L.; Landsberger, S.

2012-10-01

Using the analysis by neutron activation to determine the profile of the thorium and uranium concentration calibration factors were obtained for their use in the gamma spectrometry in situ. Three sites were selected (San Ramon, Villa de Cos y la Zacatecana) and the analysis by activation was development in the Laboratory of Nuclear Engineering Teaching of the Texas University in Austin with the nuclear reactor Ut-TRIGA. Starting from the gamma spectra in situ, the areas of normalized photo-pick of the radioisotopes were: 208 Tl and 228 Ac for the thorium series and 214 Pb and 214 Bi for the uranium series. The averages of the factors found in units of (cpm/Bq/Kg) are of 105.63±8.32 and 75.87±4.61 for the thorium and uranium, respectively. (Author)

Gamma-ray spectrometry combined with acceptable knowledge (GSAK). A technique for characterization of certain remote-handled transuranic (RH-TRU) wastes. Part 1. Methodology and techniques

International Nuclear Information System (INIS)

Hartwell, J.K.; McIlwain, M.E.

2005-01-01

Gamma-ray spectrometry combined with acceptable knowledge (GSAK) is a technique for the characterization of certain remote-handled transuranic (RH-TRU) wastes. GSAK uses gamma-ray spectrometry to quantify a portion of the fission product inventory of RH-TRU wastes. These fission product results are then coupled with calculated inventories derived from acceptable process knowledge to characterize the radionuclide content of the assayed wastes. GSAK has been evaluated and tested through several test exercises. GSAK approach is described, while test results are presented in Part II. (author)

Gamma spectrometry for chronology of recent sediments

Energy Technology Data Exchange (ETDEWEB)

Pittauerova, Daniela

2013-12-17

This thesis deals with several aspects of gamma spectrometric analysis of natural and artificial isotopes in sediments and their use as tracers for qualification and quantification of accumulation and mixing processes in different aquatic environments. Sediment cores from three distinct areas including terrigenous sediments deposited on the continental slope off NW Africa, deep sea sediments off Sumba Island and five stations from the Gulf of Eilat in the Red Sea area were measured and interpreted within this dissertation. The main concern in gamma spectrometry of voluminous environmental samples is a reliable efficiency calibration. This is specially relevant for the analysis of low energy gamma emitters (<100 keV). {sup 210}Pb, an important isotopic tracer to cover the period of the last century, is one of them. Within this work mathematical efficiency calibration was applied using a commercial software package. A series of validation tests was performed and evaluated for point and voluminous samples. When using {sup 210}Pb as a tracer it is necessary to determine its excess portion, which is not supported by ingrowth from the parent nuclide {sup 226}Ra. Its analysis is mostly performed via short lived daughter isotopes that follow after the intermediate gaseous member {sup 222}Rn. Preventing the escape of radon from the sample is a critical step before analysis due to a negative effect of supported {sup 210}Pb underestimation on the chronology, which was also documented in this thesis. Time series registering ingrowth of {sup 214}Pb and {sup 214}Bi towards radioactive equilibrium with {sup 226}Ra in different containers were evaluated for analyses of {sup 226}Ra. Direct analyses of {sup 226}Ra was compared to its detection via daughter products. A method for aligning parallel radionuclide depth profiles was described and applied successfully in two case studies from the continental slope off NW Africa and off Sumba Island, Indonesia. This is primarily important

Gamma spectrometry on MANITU 271-01 gamma scan wires

International Nuclear Information System (INIS)

Dassel, G.; Buurveld, H.A.; Minkema, J.

1994-08-01

A series of irradiation experiments (271-series) is being performed of the sustain programme for material development and characterization of the NET (Next European Torus). In the framework of the first irradiation experiment 271-01, with irradiation up to 0.2 dpa, four gamma scan wires have been examined by gamma scanning. The purpose of the gamma scan wires (GSW) is to get information about the neutron fluence distribution in the capsules during irradiation. In the stainless steel wires the nuclides Co-58, Mu-54, Fe-59 and Co-60 are produced, are characteristic for fast and thermal neutron reactions. (orig./HP)

The participation of ATOMKI in the G-2 international intercomparison of high precision gamma-ray spectrometry measurements

International Nuclear Information System (INIS)

Gaspar, A.; Lakatos, T.; Sulik, B.; Toeroek, I.

1981-01-01

International intercomparison had been organized by the IAEA in high precision gamma spectrometry. Five mixed-spectrum sources were prepared and sent to the participants by the IAEA for relative gamma emission rate measurements. This source type enables the whole measuring method and procedure to be tested. Measurements were carried out using two independent methods: a.) simple normalization to an additional radioactive source; b.) using a time variant pulse processor and random pulse generator for correction of dead-time and pile-up losses. The results agreed in most cases within +-1% with the IAEA results. (R.J.)

In situ measurements in an immerged environment of ambient gamma radiation activity and associated spectrometry

International Nuclear Information System (INIS)

Metivier, J.

1993-01-01

A set of site measurement devices composed of an ictometer, an air ionization chamber and a gamma ray spectrometry chain was modified so that the type of measurements could be carried out in an immerged environment with the equipment lying on the sediments of the prospected area. The different detectors can be controlled-and the data stored in a portable and autonomous 'PC' microcomputer from a light craft

Uranium series radioactive disequilibria study using gamma spectrometry with low energy and application to the dating in geology

International Nuclear Information System (INIS)

Khoukhi, T. El.

1992-01-01

In this work, the gamma spectrometry with low energy has been used with the help of Ge high purity planar detector, and the means and limits of this spectrometry in the applications to the dating in geology has been studied. A geological sample taken from the moroccan phosphatic deposit of Gantour, having a secondary mineralization wealth of uranium has principally been studied in application. In addition, physical models of uranium genesis have been elaborated in the course of this work in order to interpret the achieved results. 60 figs., 18 tabs., 53 refs. (F.M.)

Bibliographical study on the high-purity germanium radiation detectors used in gamma and X spectrometry

International Nuclear Information System (INIS)

Bornand, Bernard; Friant, Alain

1979-03-01

The germanium or silicon lithium-drifted detectors, Ge(Li) or Si(Li), and high-purity germanium detectors, HP Ge (impurity concentration approximately 10 10 cm -3 ), are the most commonly used at the present time as gamma and X-ray spectrometers. The HP Ge detectors for which room temperature storage is the main characteristic can be obtained with a large volume and a thin window, and are used as the Ge(Li) in γ ray spectrometry or the Si(Li) in X-ray spectrometry. This publication reviews issues from 1974 to 1978 on the state of the art and applications of the HP Ge semiconductor detectors. 101 bibliographical notices with French summaries are presented. An index for authors, documents and periodicals, and subjects is included [fr

Integrated evaluation of the geology, aero gamma spectrometry and aero magnetometry of the Sul-Riograndense Shield, southernmost Brazil

Energy Technology Data Exchange (ETDEWEB)

Hartmann, Leo A.; Savian, Jairo F., E-mail: leo.hartmann@ufrgs.br [Universidade Federal do Rio Grande do Sul (UFRS), Porto Alegre, RS (Brazil). Instituto de Geociencias; Lopes, William R. [Servico Geologico do Brasil (CPRM), Porto Alegre, RS (Brazil). Gerencia de Geologia e Mineracao

2016-03-15

An integrated evaluation of geology, aero gamma spectrometry and aero magnetometry of the Sul-Riograndense Shield is permitted by the advanced stage of understanding of the geology and geochronology of the southern Brazilian Shield and a 2010 airborne geophysical survey. Gamma rays are registered from the rocks near the surface and thus describe the distribution of major units in the shield, such as the Pelotas batholith, the juvenile São Gabriel terrane, the granulite-amphibolite facies Taquarembo terrane and the numerous granite intrusions in the foreland. Major structures are also observed, e.g., the Dorsal de Cangucu shear. Magnetic signals register near surface crustal compositions (analytic signal) and total crust composition (total magnetic signal), so their variation as measured indicates either shallow or whole crustal structures. The Cacapava shear is outstanding on the images as is the magnetic low along the N-S central portion of the shield. These integrated observations lead to the deepening of the understanding of the largest and even detailed structures of the Sul-Riograndense Shield, some to be correlated to field geology in future studies. Most significant is the presence of different provinces and their limits depending on the method used for data acquisition - geology, aero gamma spectrometry or aero magnetometry. (author)

European coordination of environmental airborne gamma ray spectrometry. Final report 1999

International Nuclear Information System (INIS)

Sanderson, D.C.; McLeod, J.J.

1999-04-01

This Concerted Action was funded under the EURATOM Nuclear Fission Safety Programme of the Fourth Framework Programme, and was initiated to address transnational issues relating to environmental airborne gamma ray spectrometry (AGS). Significant development of AGS systems and teams has taken place within Europe during the period following the Chernobyl accident. The technique is increasingly recognised as particularly relevant to emergency response. It is also uniquely capable of acquiring data on anthropogenic and natural radionuclides on regional, national and international scales, for reference purposes, ecological studies and epidemiological research. Prior to this EU programme the methodologies and systems used by European AGS teams had undergone rapid and largely uncoordinated development. This raised questions about comparability of systems, applications, and data between teams, duplication of research, the scope for transnational cooperation and standardisation, and future research and development needs in the field. This project, which brought together ten AGS teams from across Europe, was formed to address these issues. The work was conducted in three stages and has largely succeeded in its objectives. An active communication network was developed for collaboration and exchange of information, and to start the process of harmonisation of the different methodologies used by individual AGS teams. Two formal partners' meetings were organised, the first aimed at defining the EU capability in AGS, the second, in the form of an international symposium (RADMAGS), was aimed at reviewing developments on future research needs and the scope for standardisation. This report gives full details of the project and its deliverables together with discussion of the further needs in support of transnational harmonisation of this topic. The European Capability for AGS was defined at an early stage of the project, and monitored throughout. An EU Bibliography on AGS

Gamma-ray spectrometry combined with acceptable knowledge (GSAK). A technique for characterization of certain remote-handled transuranic (RH-TRU) wastes. Part 2. Testing and results

International Nuclear Information System (INIS)

Hartwell, J.K.; McIlwain, M.E.

2005-01-01

Gamma-ray spectrometry combined with acceptable knowledge (GSAK) is a technique for the characterization of certain remote-handled transuranic (RH-TRU) wastes. GSAK uses gamma-ray spectrometry to quantify a portion of the fission product inventory of RH-TRU wastes. These fission product results are then coupled with calculated inventories derived from acceptable process knowledge to characterize the radionuclide content of the assayed wastes. GSAK has been evaluated and tested through several test exercises. These tests and their results are described; while the former paper in this issue presents the methodology, equipment and techniques. (author)

Experimental determination of nuclear reaction rates (n,γ) by the gamma-rays capture spectrometry technique

International Nuclear Information System (INIS)

Lucatero, M.A.

1976-01-01

The technique of the gamma-rays capture spectrometry was used in the experimental determination of nuclear reaction rates of the type (n,γ). This technique consists in the incidence of a thermal neutrons collimated beam upon a sample, detecting the capture spectrum of gamma rays emitted at a solid fixed angle. In the determination of the efficiency curve intrinsic to the detection electronic system the reactions 199 Hg(n,γ) 200 Hg, 56 Fe(n,γ) 57 Fe and 63 Cu(n,γ) 64 Cu were used with the energy of the gamma rays capture of 5.976, 7.635 and 7.915 Mev respectively, through the irradiation of standard samples of Hg(175.3g), Fe(110.4g) and Cu(108.5g) of cylindrical geometry the two former and parallelepiped the latter. The problem concerning the corrections due to the thermal neutrons flux depression, the gammas auto-attenuation, and the geometric factor due to the cylindrical and parallelepiped geometry are involved in the data process. The experimental determination of the reaction 35 Cl(n,γ) 36 Cl rate was made through the observation of the gamma caputre of 6.111 Mev when a sample of CaCl 2 of cylindrical geometry was irradiated. This rate can be favorably compared with the reaction rate determined theoretically. (author)

Gamma-ray spectrometry of granitic suites of the Paranaguá Terrane, Southern Brazil

Science.gov (United States)

Weihermann, Jessica Derkacz; Ferreira, Francisco José Fonseca; Cury, Leonardo Fadel; da Silveira, Claudinei Taborda

2016-09-01

The Paranaguá Terrane, located in the coastal portion of the states of Santa Catarina, Paraná and São Paulo in Southern Brazil is a crustal segment constituted mainly by an igneous complex, with a variety of granitic rocks inserted into the Serra do Mar ridge. The average altitude is approximately 1200 m above sea level, with peaks of up to 1800 m. Due to the difficulty of accessing the area, a shortage of outcrops and the thick weathering mantle, this terrane is understudied. This research aims to evaluate the gamma-ray spectrometry data of the granitic suites of the Paranaguá Terrane, in correspondence with the geological, petrographical, lithogeochemical, relief and mass movement information available in the literature. Aerogeophysical data were acquired along north-south lines spaced at 500 m, with a mean terrain clearance of 100 m. These data cover potassium (K, %), equivalent in thorium (eTh, ppm) and equivalent in uranium (eU, ppm). After performing a critical analysis of the data, basic (K, eU, eTh) and ternary (R-K/G-eTh/B-eU) maps were generated and then superimposed on the digital elevation model (DEM). The investigation of the radionuclide mobility across the relief and weathering mantle consisted of an analysis of the schematic profiles of elevation related with each radionuclide; a comparison of the K, eU and eTh maps with their 3D correspondents; and the study of mass movements registered in the region. A statistical comparison of lithogeochemical (K, U, Th) and geophysical (K, eU, eTh) data showed consistency in all the granitic suites studied (Morro Inglês, Rio do Poço and Canavieiras-Estrela). Through gamma-ray spectrometry, it was possible to establish relationships between scars (from mass movements) and the gamma-ray responses as well as the radionuclide mobility and the relief and to map the granitic bodies.

GammaLog Playback 1.0 - mobile gamma ray spectrometry software

International Nuclear Information System (INIS)

Watson, R.J.; Smethurst, M.A.

2011-01-01

The Geological Survey of Norway (NGU) operates a mobile gamma ray spectrometer system which can be used in nuclear emergency situations to determine the location and type of orphan sources, or the extent and type of fallout contamination. The system consists of a 20 litre (16 litre downward and 4 litre upward looking) RSX-5 NaI detector and spectrometer, and can be mounted in fixed wing aircraft, helicopters, or vans/cars as appropriate. NGU has developed its own data acquisition and analysis software for this system. GammaLog (Smethurst 2005) controls the acquisition, display, and storage of data from the spectrometer, and performs real-time data analysis including estimation of dose rates and fallout concentrations, and separation of geological and anthropogenic components of the signal. The latter is particularly important where the geological radioisotope signal varies strongly from one place to another, and makes it easier to locate and identify anthropogenic sources which might otherwise be difficult to separate from the geological background signal. A modified version of GammaLog has been developed, GammaLog Playback, which allows the replay of previously acquired GammaLog datasets, while performing similar processing and display as the GammaLog acquisition software. This allows datasets to be reviewed and compared in the field or during post-survey analysis to help plan subsequent measurement strategies.(Au)

Self-absorption corrections of various sample-detector geometries in gamma-ray spectrometry using sample Monte Carlo Simulations

International Nuclear Information System (INIS)

Ahmad Saat; Appleby, P.G.; Nolan, P.J.

1997-01-01

Corrections for self-absorption in gamma-ray spectrometry have been developed using a simple Monte Carlo simulation technique. The simulation enables the calculation of gamma-ray path lengths in the sample which, using available data, can be used to calculate self-absorption correction factors. The simulation was carried out on three sample geometries: disk, Marinelli beaker, and cylinder (for well-type detectors). Mathematical models and experimental measurements are used to evaluate the simulations. A good agreement of within a few percents was observed. The simulation results are also in good agreement with those reported in the literature. The simulation code was carried out in FORTRAN 90,

Basics of Gamma Ray Detection

Energy Technology Data Exchange (ETDEWEB)

Stinnett, Jacob [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Venkataraman, Ram [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-09-13

The objective of this training is to explain the origin of x-rays and gamma rays, gamma ray interactions with matter, detectors and electronics used in gamma ray-spectrometry, and features of a gamma-ray spectrum for nuclear material that is safeguarded.

Survey of natural radioactivity levels in Ilex paraguariensis (St. Hil.) by gamma-ray spectrometry

International Nuclear Information System (INIS)

Scheibel, Viviane; Appoloni, Carlos Roberto

2007-01-01

The mate tea (Ilex paraguariensis - St. Hil.) is a beverage broadly cultivated and consumed in Brazil. The radioactive traces present in three trademarks of toasted mate tea produced at the south of Brazil were analyzed. Measurements were carried out by gamma-ray spectrometry. The average value for the 40 K activity measured for marks A, B and C was 1216 ± 8, 1047 ± 14 and 666 ± 13 Bq.kg -1 , respectively. The 137 Cs activity was lower than the limit of detection. (author)

The use of gamma spectrometry in mapping alteration zones in Olkiluoto

International Nuclear Information System (INIS)

Ojala, J.V.; Turunen, P.; Eilu, P.; Julkunen, A.; Gehoer, S.

2007-08-01

In the Olkiluoto site, a detailed gammaspectrometry log from the drill hole OL-KR27 was used to estimate the concentrations of K, Th and U. The gamma spectrometry results, lithological variations, and kaolinite and illite alteration visually mapped from the drill hole were compared. The result indicate that the Th/K ratio correlates best with lithology and that, in most cases, the changes in the ratio indicate lithological contacts and rising or falling trends of Th/K ratio with some peaks have some correlation with the kaolinite-illite alteration. From the result it is suggested that that very variable Th/K ratio is a reasonably good indicator of alteration zones even in the migmatic gneiss area in the Olkiluoto site. (orig.)

Developments in gamma-ray spectrometry: systems, software, and methods-II. 3. Low-Energy Gamma-Ray Spectrometry Using a Compton-Suppressed Telescope Detector

International Nuclear Information System (INIS)

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

2001-01-01

The Savannah River Technology Center (SRTC) utilizes gamma-ray spectrometry in studying numerous areas of applied interest to the Savannah River Site (SRS). For example, analyses of long-lived gamma-ray-emitting fission products and actinides are required to meet waste characterization, process holdup, environmental restoration, and decontamination and decommissioning efforts. A significant portion of the overall effort centers on measurements of gamma rays having energies below several hundred kilo-electron-volts. To assist these efforts, the SRTC recently acquired a spectrometer system that provides lower natural and Compton scattered background levels while achieving relatively high counting efficiencies for low-energy gamma rays. The combination of high efficiency and low background provides factor-of- 2-to-4 improvements in minimum detectable activities and allows meeting programmatic objectives with shorter measurement times. Numerous Compton-suppression spectrometers have been reported since the concept was first advanced. The spectrometer consists of two high-purity germanium detectors in a telescope configuration surrounded by a background /Compton-suppression sodium iodide detector. The front germanium detector is a 20-mm-thick x 60-mm-diam broad energy spectrometer, and the rear detector is a 40% efficient 61- mm-diam x 60-cm-thick closed-end coaxial spectrometer. The cryostat housing the germanium detectors (a) includes a carbon composite window for transmitting low-energy gamma rays, (b) is in a J-type configuration to mask the germanium detectors from natural activities in the cryo-pumping media, and (c) is fabricated from materials selected for low background. The telescope detector is in the 8.6-cm-inside-diameter annulus of a 22.9- x 22.9-cm sodium iodide detector encased in a 10-cm-thick lead shield. The counting system is located in a basement counting room having ∼60-cm-thick concrete walls. Initial tests show that the low-energy segment of

Assessing sample attenuation parameters for use in low-energy efficiency transfer in gamma-ray spectrometry

International Nuclear Information System (INIS)

Bruggeman, M.; Verheyen, L.; Vidmar, T.; Liu, B.

2016-01-01

We present a numerical fitting method for transmission data that outputs an equivalent sample composition. This output is used as input to a generalised efficiency transfer model based on the EFFTRAN software integrated in a LIMS. The procedural concept allows choosing between efficiency transfer with a predefined sample composition or with an experimentally determined composition based on a transmission measurement. The method can be used for simultaneous quantification of low-energy gamma emitters like "2"1"0Pb, "2"4"1Am, "2"3"4Th in typical environmental samples. - Highlights: • New fitting method for experimentally determined attenuation coefficients. • Generalised efficiency transfer with EFFTRAN based on transmission measurements. • Method of generalized efficiency transfer integrated in LIMS. • Method applicable to gamma-ray spectrometry of environmental samples.

Gamma spectrometry and plastic-scintillator inherent background

International Nuclear Information System (INIS)

Pomerantsev, V.V.; Gagauz, I.B.; Mitsai, L.I.; Pilipenko, V.S.; Solomonov, V.M.; Chernikov, V.V.; Tsirlin, Y.A.

1988-01-01

The authors measured the energy resolution for a linear dependence of light yield on gamma radiation energy of gamma spectrometers based on plastic scintillation detectors for several plastic scintillators. If there were several gamma lines from the source the line with the highest energy was used to eliminate distortion due to overlap from the Compton background from gamma radiation of higher energy. Attenuation lengths were calculated. The tests were based on three modes of interaction between the gamma radiation and the scintillator: Compton scattering, the photoelectric effect, and pair formation. The contribution from light collection was also considered. The scintillators tested included polystyrene, polymethyl methacrylate, cesium iodide, and sodium iodide. Gamma sources included cesium 137, sodium 22, potassium 40, yttrium 88, thorium 232, and plutonium-beryllium

International comparison of methods to test the validity of dead-time and pile-up corrections for high-precision. gamma. -ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Houtermans, H.; Schaerf, K.; Reichel, F. (International Atomic Energy Agency, Vienna (Austria)); Debertin, K. (Physikalisch-Technische Bundesanstalt, Braunschweig (Germany, F.R.))

1983-02-01

The International Atomic Energy Agency organized an international comparison of methods applied in high-precision ..gamma..-ray spectrometry for the correction of dead-time and pile-up losses. Results of this comparison are reported and discussed.

A study for natural radioactivity levels in some soil samples using gamma spectrometry

International Nuclear Information System (INIS)

Mohamed, Yousif Hassab El Rasoul

1997-05-01

The purpose of this study was to investigate a few selected soil samples and to study their natural radioactivity using gamma spectrometry. The first sample was a rock phosphate from Nuba mountains region which is being considered as a low cost fertilizer. Another sample came from Miri lake area (Nuba mountains) which is known to have elevated natural radioactivity level. The other four samples came from different other regions in Sudan for comparison. The idea was to identify the radioactive nuclides present in these soil samples, to trace their sources and to determine the activity present in them. (Author)

Efficiency transfer using the GEANT4 code of CERN for HPGe gamma spectrometry

International Nuclear Information System (INIS)

Chagren, S.; Tekaya, M.Ben; Reguigui, N.; Gharbi, F.

2016-01-01

In this work we apply the GEANT4 code of CERN to calculate the peak efficiency in High Pure Germanium (HPGe) gamma spectrometry using three different procedures. The first is a direct calculation. The second corresponds to the usual case of efficiency transfer between two different configurations at constant emission energy assuming a reference point detection configuration and the third, a new procedure, consists on the transfer of the peak efficiency between two detection configurations emitting the gamma ray in different energies assuming a “virtual” reference point detection configuration. No pre-optimization of the detector geometrical characteristics was performed before the transfer to test the ability of the efficiency transfer to reduce the effect of the ignorance on their real magnitude on the quality of the transferred efficiency. The obtained and measured efficiencies were found in good agreement for the two investigated methods of efficiency transfer. The obtained agreement proves that Monte Carlo method and especially the GEANT4 code constitute an efficient tool to obtain accurate detection efficiency values. The second investigated efficiency transfer procedure is useful to calibrate the HPGe gamma detector for any emission energy value for a voluminous source using one point source detection efficiency emitting in a different energy as a reference efficiency. The calculations preformed in this work were applied to the measurement exercise of the EUROMET428 project. A measurement exercise where an evaluation of the full energy peak efficiencies in the energy range 60–2000 keV for a typical coaxial p-type HpGe detector and several types of source configuration: point sources located at various distances from the detector and a cylindrical box containing three matrices was performed. - Highlights: • The GEANT4 code of CERN has been used to transfer the peak efficiency from point to points and voluminous detection configurations in HPGe gamma

Assessment of the suitability of different random number generators for Monte Carlo simulations in gamma-ray spectrometry

International Nuclear Information System (INIS)

Cornejo Diaz, N.; Vergara Gil, A.; Jurado Vargas, M.

2010-01-01

The Monte Carlo method has become a valuable numerical laboratory framework in which to simulate complex physical systems. It is based on the generation of pseudo-random number sequences by numerical algorithms called random generators. In this work we assessed the suitability of different well-known random number generators for the simulation of gamma-ray spectrometry systems during efficiency calibrations. The assessment was carried out in two stages. The generators considered (Delphi's linear congruential, mersenne twister, XorShift, multiplier with carry, universal virtual array, and non-periodic logistic map based generator) were first evaluated with different statistical empirical tests, including moments, correlations, uniformity, independence of terms and the DIEHARD battery of tests. In a second step, an application-specific test was conducted by implementing the generators in our Monte Carlo program DETEFF and comparing the results obtained with them. The calculations were performed with two different CPUs, for a typical HpGe detector and a water sample in Marinelli geometry, with gamma-rays between 59 and 1800 keV. For the Non-periodic Logistic Map based generator, dependence of the most significant bits was evident. This explains the bias, in excess of 5%, of the efficiency values obtained with this generator. The results of the application-specific assessment and the statistical performance of the other algorithms studied indicate their suitability for the Monte Carlo simulation of gamma-ray spectrometry systems for efficiency calculations.

Assessment of the suitability of different random number generators for Monte Carlo simulations in gamma-ray spectrometry.

Science.gov (United States)

Díaz, N Cornejo; Gil, A Vergara; Vargas, M Jurado

2010-03-01

The Monte Carlo method has become a valuable numerical laboratory framework in which to simulate complex physical systems. It is based on the generation of pseudo-random number sequences by numerical algorithms called random generators. In this work we assessed the suitability of different well-known random number generators for the simulation of gamma-ray spectrometry systems during efficiency calibrations. The assessment was carried out in two stages. The generators considered (Delphi's linear congruential, mersenne twister, XorShift, multiplier with carry, universal virtual array, and non-periodic logistic map based generator) were first evaluated with different statistical empirical tests, including moments, correlations, uniformity, independence of terms and the DIEHARD battery of tests. In a second step, an application-specific test was conducted by implementing the generators in our Monte Carlo program DETEFF and comparing the results obtained with them. The calculations were performed with two different CPUs, for a typical HpGe detector and a water sample in Marinelli geometry, with gamma-rays between 59 and 1800 keV. For the Non-periodic Logistic Map based generator, dependence of the most significant bits was evident. This explains the bias, in excess of 5%, of the efficiency values obtained with this generator. The results of the application-specific assessment and the statistical performance of the other algorithms studied indicate their suitability for the Monte Carlo simulation of gamma-ray spectrometry systems for efficiency calculations. Copyright 2009 Elsevier Ltd. All rights reserved.

Activation analysis using {gamma} photons; Analyse par activation aux photons {gamma}

Energy Technology Data Exchange (ETDEWEB)

Engelmann, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

This report summarizes all the data required for using photonuclear reactions in the field of analysis. After a brief review of the elementary properties of nuclear reactions induced by photon irradiation, the main characteristics are given of high energy (E > 20 MeV) Bremsstrahlung sources. The principle of activation analysis based on the use of photons is given. Actual examples of the analytic possibilities are described in detail, in particular in the case of the determination of very small quantities (< 10{sup -6}) of C, N, O and F. The influence of interfering nuclear reactions is discussed. (author) [French] Ce rapport se propose de resumer l'ensemble des connaissances indispensables pour l'utilisation des reactions photonucleaires a des fins analytiques. Apres quelques rappels concernant les proprietes elementaires des reactions nucleaires induites par irradiation dans les photons, les principales caracteristiques des sources de rayonnement de freinage de haute energie (E > 20 MeV)| sont donnees. Le principe de l'analyse par activation aux photons est rappele. Des exemples concrets sur les possibilites analytiques sont developpes, particulierement en ce qui concerne la determination de quantites tres faibles (< 10{sup -6}) de C, N, O et F. L'influence des reactions nucleaires parasites est discutee. (auteur)

Radiochemical separation of {sup 231}Pa from siliceous cake prior to its determination by gamma ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Dalvi, Aditi A. [Bhabha Atomic Research Centre, Mumbai (India). Analytical Chemistry Div.; Homi Bhabha National Institute, Mumbai (India); Verma, Rakesh

2017-07-01

A simple and fast radiochemical method for the separation of protactinium ({sup 231}Pa) from siliceous cake for its determination by gamma ray spectrometry is described. The method involves (a) a novel approach, the fusion of the siliceous cake with sodium peroxide, (b) the dissolution of the fused mass in nitric acid and (c) the co-precipitation of {sup 231}Pa with manganese dioxide formed in-situ by the addition of solid manganous sulfate and potassium permanganate to the solution. The fusion, effected in a single step, is simpler and highly effective in comparison to methods reported hitherto in literature. The radiochemical yield of {sup 231}Pa, determined using 311.9 keV gamma ray of {sup 233}Pa radiotracer is quantitative (∝90%). The decontamination factors calculated using gamma ray spectrometry and energy dispersive X-ray fluorescence measurements show that the separation from the interfering radionuclides is high whereas separation from major and minor elements is good. Separation by ion-exchange method in hydrochloric acid, hydrofluoric acid and oxalic acid media have comparatively much lower yields. The concentration of {sup 231}Pa in the siliceous cake measured using interference-free 283.6 keV gamma ray was found to be (6.4 ± 0.33) μg kg{sup -1}. The measured concentration of {sup 231}Pa was well above the limit of quantitation whereas the coefficient of variation was ∝5%. The improvement in the limit of detection was due to the reduction in spectral background. Systematic evaluation of various uncertainty parameters showed that the major contributors to the combined uncertainty were efficiency of the high purity germanium detector and the counting statistics. The present sample decomposition and separation methods are robust, simple to perform and can be effectively used for the determination and hence source prospecting of protactinium.

Gamma spectrometry of 285-04 ILAS gamma scan wires

International Nuclear Information System (INIS)

Dassel, G.; Buurveld, H.A.; Plakman, J.C.

1996-12-01

In the frame work of their on-going sustain programme for the material development and characterization of fusion reactors, ECN is investigating the irradiation behaviour of ferritic/martensitic steels. In the fourth irradiation experiment 285-04, 55 steel tensile samples have been irradiated up to 2.5 dpa. Four gamma scan wires from this experiment have been examined by gamma scanning. The results of the measurements have been described in this report. (orig.)

Use of wavelet based iterative filtering to improve denoising of spectral information for in-vivo gamma spectrometry

International Nuclear Information System (INIS)

Paul, Sabyasachi; Sarkar, P.K.

2012-05-01

The characterization of radionuclide in the in-vivo monitoring analysis using gamma spectrometry poses difficulty due to very low activity level in biological systems. The large statistical fluctuations often make identification of characteristic gammas from radionuclides highly uncertain, particularly when interferences from progenies are also present. A new wavelet based noise filtering methodology has been developed for better detection of gamma peaks while analyzing noisy spectrometric data. This sequential, iterative filtering method uses the wavelet multi-resolution approach for the noise rejection and inverse transform after soft thresholding over the generated coefficients. Analyses of in-vivo monitoring data of 235 U and 238 U have been carried out using this method without disturbing the peak position and amplitude while achieving a threefold improvement in the signal to noise ratio, compared to the original measured spectrum. When compared with other data filtering techniques, the wavelet based method shows better results. (author)

Calibration of the High Resolution Gamma Spectrometry Detection Systems from the Environmental Radioactivity Unit and Radiological Surveillance (ARU and RV); Calibracion de los Sistemas Detectores de Espectrometria Gamma de Alta Resolucion de la Unidad de Radiactividad Ambiental y Vigilancia Radiologica (URA y VR)

Energy Technology Data Exchange (ETDEWEB)

Suarez-Navarro, J. A.; Gasco, C.; Arana, M.; Suanez, A.

2012-11-01

In accordance with international regulations and with the quality criteria imposed by the internal quality system of the laboratory of gamma spectrometry, which belongs to the Unit of Environmental Radioactivity and Radiation Monitoring (URA y VR), it is necessary to perform a periodic calibration of the measurement systems of gamma spectrometry. The equipment calibration carries with the need for the preparation of the geometries of measurement and calibration in energy and in efficiencies. This report reflects the procedures for the preparation of the wide range of geometries available in the laboratory, as well as the different calibrations performed with those geometries in almost all the laboratory gamma detectors using the CANBERRA software Genie 2k. (Author) 9 refs.

Rapid non-destructive quantitative estimation of urania/ thoria in mixed thorium uranium di-oxide pellets by high-resolution gamma-ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Shriwastwa, B.B.; Kumar, Anil; Raghunath, B.; Nair, M.R.; Abani, M.C.; Ramachandran, R.; Majumdar, S.; Ghosh, J.K

2001-06-01

A non-destructive technique using high-resolution gamma-ray spectrometry has been standardised for quantitative estimation of uranium/thorium in mixed (ThO{sub 2}-UO{sub 2}) fuel pellets of varying composition. Four gamma energies were selected; two each from the uranium and thorium series and the time of counting has been optimised. This technique can be used for rapid estimation of U/Th percentage in a large number of mixed fuel pellets from a production campaign.

Rapid non-destructive quantitative estimation of urania/ thoria in mixed thorium uranium di-oxide pellets by high-resolution gamma-ray spectrometry

International Nuclear Information System (INIS)

Shriwastwa, B.B.; Kumar, Anil; Raghunath, B.; Nair, M.R.; Abani, M.C.; Ramachandran, R.; Majumdar, S.; Ghosh, J.K.

2001-01-01

A non-destructive technique using high-resolution gamma-ray spectrometry has been standardised for quantitative estimation of uranium/thorium in mixed (ThO 2 -UO 2 ) fuel pellets of varying composition. Four gamma energies were selected; two each from the uranium and thorium series and the time of counting has been optimised. This technique can be used for rapid estimation of U/Th percentage in a large number of mixed fuel pellets from a production campaign

Two low-level gamma spectrometry systems of the IAEA Safeguards Analytical Laboratory

Energy Technology Data Exchange (ETDEWEB)

Parus, J L [IAEA, SAL, Vienna (Austria); Raab, W [IAEA, SAL, Vienna (Austria); Donohue, D [IAEA, SAL, Vienna (Austria); Jansta, V [IAEA, SAL, Vienna (Austria); Kierzek, J [IAEA, SAL, Vienna (Austria)

1997-03-01

A gamma spectrometry system designed for the measurement of samples with low and medium radioactivity (activity from a few to about 10{sup 4} Bq in the energy range from 25 to 2700 keV) has been installed at the IAEA Safeguards Analytical Laboratory in Seibersdorf. The system consists of 3 low level detectors: (1) n-type coaxial Ge with 42.4% relative efficiency, 1.85 keV FWHM at 1.33 MeV (2) planar Ge with 2000 mm{sup 2} area and 20 mm thickness, 562 eV FWHM at 122 keV (3) NaI(Tl) annulus of 25.4 cm diameter and 25.4 cm height, hole diameter 90 mm. (orig./DG)

Processing of gamma-ray spectrometric logs

International Nuclear Information System (INIS)

Umiastowski, K.; Dumesnil, P.

1984-10-01

CEA (Commissariat a l'Energie Atomique) has developped a gamma-ray spectrometric tool, containing an analog-to-digital converter. This new tool permits to perform very precise uranium logs (natural gamma-ray spectrometry), neutron activation logs and litho-density logs (gamma-gamma spectrometric logs). Specific processing methods were developped to treate the particular problems of down-hole gamma-ray spectrometry. Extraction of the characteristic gamma-ray peak, even if they are superposed on the background radiation of very high intensity, is possible. This processing methode enables also to obtain geological informations contained in the continuous background of the spectrum. Computer programs are written in high level language for SIRIUS (VICTOR) and APOLLO computers. Exemples of uranium and neutron activation logs treatment are presented [fr

Direct dating of Tantavel man by non-destructive gamma-ray spectrometry of fossil human skull Arago XXI

International Nuclear Information System (INIS)

Yokoyama, Yuji; Nguyen, Huu-Van

1981-01-01

A new method to date prehistoric samples is proposed. Non-destructive gamma-ray spectrometry with semi-conductor detector was used in the direct determination of the activities of 238 U, 234 U, 231 Pa, 230 Th and 228 Th. An age of (400sub(-96)sup(+infinite))x10 3 years was obtained from the 230 Th/ 238 U ratio of 0.975+-0.030 [fr

Gamma spectrometry of 285-03 ILAS gamma scan wires

International Nuclear Information System (INIS)

Dassel, G.; Buurveld, H.A.; Plakman, J.C.

1996-12-01

In the frame work of their on-going sustain programme for the material development and characterization of fusion reactors, ECN is investigating the irradiation behaviour of ferritic/martensitic steels. In the third irradiation experiment 285-03, 55 vanadium (V-4Cr-4Ti) tensile samples have been irradiated up to 6 dpa. Four gamma scan wires from this experiment have been examined by gamma scanning. The results of the measurements have been described in this report. (orig.)

Determination of activity by gamma spectrometry of radionuclides present in drums of residues generated in nuclear centrals

International Nuclear Information System (INIS)

Aguiar, J.C.; Fernandez, J.

2006-01-01

The generation of radioactive residuals in nuclear centrals as CNA I (Atucha I Nuclear Central) and CNE (Embalse Nuclear Central) makes that the measurement of those radionuclides has been a previous stage to the waste management. A method used in those nuclear centrals it is the gamma spectrometry with HPGe detectors, previous to the immobilization of the residual in a cemented matrix, with this the contact with the external agents and its possible dispersion to the atmosphere in the short term is avoided. The ARN (Nuclear Regulatory Authority) of Argentina it carries out periodically intercomparisons and evaluations of the measurement and procedures systems used in the nuclear power stations for the correct measurement and determination of activity of radioactive residuals by gamma spectrometry. In this work an independent method of measurement is exposed to the nuclear power stations. To determine the activity of the residuals by gamma spectrometry deposited in drums, it is required of the precise knowledge of the efficiency curve for such geometry and matrix. Due to the RNA doesn't have a pattern of these characteristics, a mathematical model has been used to obtain this efficiency curve. For it, it is necessary to determine previously: 1) the geometric efficiency or solid angle sustained by the source-detector system (drum-detector) applying a mathematical model described in this work. 2) To estimate the auto-attenuation factor that present the photons in the cemented matrix, these calculations are carried out with a simple equation and its are verified with the Micro Shield 6.10 program. The container commonly used by these nuclear power stations its are drums for 220 liters constructed with SAE 1010 steel and with a thickness of 0.127 cm, with an approximate weight 7.73 Kg., internal diameter of 57.1 cm, and height: 87 cm. The results obtained until the moment register a discrepancy from 5 to 10% with relationship to the measurements carried out by the

Determination of Natural Radioactivity in Building Materials with Gamma Spectrometry

International Nuclear Information System (INIS)

Turki, Faten

2010-01-01

In the setting of this work, the natural radioactivity of building materials used in Tunisia has been measured by gamma spectrometry. These products have been ground and dried at 100 degree for 12 h. Then, they have been homogenized, weighed and finally conditioned during 23 days in order to reach the radioactive equilibrium. The measures' results proved that all building materials studied except bauxite and the ESC clay, possess doses lower than the acceptable limit (1 mSv.an-1). However, the possibility of reinforcement of the natural radioactivity in some industry of building can exist. To insure that the cement, the most used in the world, don't present any radiological risk on the workers' health, a survey has been made in the factory - les Ciments de Bizerte - about its manufacture's process. The results of this survey showed that this product can be considered like a healthy product.

Gamma-ray spectrometry data collection and reduction by simple computing systems

International Nuclear Information System (INIS)

Op de Beeck, J.

1975-01-01

The review summarizes the present state of the involvement of relatively small computing devices in the collection and processing of gamma-ray spectrum data. An economic and utilitarian point of view has been chosen with regard to data collection in order to arrive at practically valuable conclusions in terms of feasibility of possible configurations with respect to their eventual application. A unified point of view has been adopted with regard to data processing by developing an information theoretical approach on a more or less intuitive level in an attempt to remove the largest part of the virtual disparity between the several processing methods described in the literature. A synoptical introduction to the most important mathematical methods has been incorporated, together with a detailed theoretical description of the concept gamma-ray spectrum. In accordance with modern requirements, the discussions are mainly oriented towards high-resolution semiconductor detector-type spectra. The critical evaluation of the processing methods reviewed is done with respect to a set of predefined criteria. Smoothing, peak detection, peak intensity determination, overlapping peak resolving and detection and upper limits are discussed in great detail. A preferred spectrum analysis method combining powerful data reduction properties with extreme simplicity and speed of operation is suggested. The general discussion is heavily oriented towards activation analysis application, but other disciplines making use of gamma-ray spectrometry will find the material presented equally useful. Final conclusions are given pointing to future developments and shifting their centre of gravity towards improving the quality of the measurements rather than expanding the use of tedious and sophisticated mathematical techniques requiring the limits of available computational power. (author)

A comparative study for the correction of random gamma ray summing effect in HPGe - detector based gamma ray spectrometry

International Nuclear Information System (INIS)

Rajput, M.U.

2007-01-01

Random coincidence summing of gamma rays is a potential source of errors in gamma ray spectrometry. The effect has a little significance at low counting rates but becomes increasingly important at high counting rates. Careful corrections are required to avoid the introduction of errors in quantitative based measurements. Several correction methods have been proposed. The most common is the pulser method that requires a precision Pulse Generator in the electronic circuitry to provide reference peak. In this work, a comparative study has been carried out both by using pulser method and utilizing radioactive source based method. This study makes the use of 137 Cs radionuclide as a fixed source and the 241 Am as a varied source. The dead time of the system has been varied and the acquisition of the spectra at each position yielded the resulted peak areas with pulsed pile up losses. The linear regression of the data has been carried out. The study has resulted in establishing a consistent factor that can be used as the characteristic of the detector and thereby removes the need of the calibrated or precise Pulse Generator. (author)

Use of the helium-3 proportional counter for neutron spectrometry; Utilisation du compteur proportionnel a helium 3 pour la spectrometrie des neutrons

Energy Technology Data Exchange (ETDEWEB)

Vialettes, H; Le Thanh, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

Up to now, two methods have been mainly used for neutron spectrometry near nuclear installations: - photographic emulsion spectrometry - the so-called, 'multisphere' technique spectrometry. The first method, which is fairly difficult to apply, has a threshold energy of about 500 keV; this is a big disadvantage for an apparatus which has to be used for spectrometry around nuclear installations where the neutron radiation is very much degraded energetically. The second method does not suffer from this disadvantage but the results which it yields are only approximate. In order to extend the energy range of the neutron spectra studied with sufficient accuracy the use of a helium-3 proportional counter has been considered. This report presents the principles of operation of the helium-3 spectrometer, and the calculation methods which make it possible to take into account the two main effects tending to deform the spectra obtained: - energy absorption by the walls of the counter, - energy loss of the incident neutrons due to elastic collisions with helium-3 nuclei. As an example of the application, the shape of the neutron spectrum emitted by a polonium-lithium source is given; the results obtained are in excellent agreement with theoretical predictions. (authors) [French] Jusqu'ici deux methodes ont ete utilisees principalement pour la spectrometrie des neutrons autour des installations nucleaires: - la spectrometrie par emulsions photographiques - la spectrometrie par la technique dite des multispheres. La premiere methode, d'un emploi assez delicat presente un seuil en energie d'environ 500 keV qui est un obstacle serieux a la spectrometrie autour des installations nucleaires ou le rayonnement neutronique est tres degrade en energie. La deuxieme methode ne presente pas cet inconvenient mais les resultats qu'elle permet d'obtenir ne sont qu'approches. Pour etendre la gamme d'energie des spectres de neutrons etudies avec une precision suffisante, l'utilisation du

Simultaneous determination of RA-226, natural uranium and natural thorioum by gamma-ray spectrometry INa(Tl) in solid samples

International Nuclear Information System (INIS)

Salvador, S.; Navarro, T.; Alvarez, A.

1990-01-01

A method has been described to determine activities of Ra-226, natural uranium, and natural thorium, by gamma-ray spectrometry. The system was calibrated for efficiency by using synthetic calibrated standards. It is necessary, in the samples, to assume secular equilibrium between Ra-226 and Th-232 and its daughters nuclides, and U-238 and its immediate daughter Th-234, because the photopeaks measured are from these dsaugthers. Our results indicate that a non destructive gamma spectrometric method can ofter replace the radiochemical techniques used in measuring radiactivities in this type of samples. (Author). 9 refs

Accuracy in gamma spectrometry: Pileup, dead time, and fast electornics

International Nuclear Information System (INIS)

Lindstrom, R.M.

1993-01-01

An important source of inaccuracy in neutron activation analysis is the nonlinear throughput of the counting system, especially at high counting rates. Losses, due to the finite time needed for events to happen, occur in all parts of the spectrometer system: the germanium detector crystal, preamplifier, amplifier, analog-digital converter (ADC), and MCA or computer. The slowest unbuffered units are the ADC and the amplifier, followed by the crystal. Even with modern fast electronics, losses can be important, although compensating circuits can greatly improve accuracy if they are used correctly. The ADC dead time is less of a problem than it was a decade ago. For example, a modern successive-approximation ADC in the author's laboratory takes 6 μs to digitize a gamma ray in the middle of an 8192-channel spectrum, compared with 60 μs for the Wilkinson device that it replaced. Dead-time circuits in MCAs for many years have compensated very well for this dead time. Pulse pileup is as important as ADC dead time. Random coincidence, the accidental arrival of the signal from two nonrelated gamma rays at the amplifier in a time short compared to the shaping time, results in a composite pulse that distorts the spectrum. For accurate spectrometry, each such random-sum pulse should be excluded from the spectrum (pileup rejection), and the system dead time must be adjusted to compensate for the time the system is busy analyzing this rejected event (pileup live-time correction)

A low-energy set-up for gamma-ray spectrometry of NORM tailored to the needs of a secondary smelting facility.

Science.gov (United States)

Lutter, G; Schreurs, I Vandael; Croymans, T; Schroeyers, W; Schreurs, S; Hult, M; Marissens, G; Stroh, H; Tzika, F

2017-08-01

A measurement station dedicated for quantitative radiological characterisation of naturally occurring radionuclides in a metallurgical company and based on gamma-ray spectrometry was developed. The station is intended for performing quality control of final non-ferrous metal products and for radiological checks of incoming materials. A low-background point-contact HPGe-detector was used and the signal was split in two branches to enable collecting simultaneously spectra with high amplification (for gamma-ray energies below 250keV) and low amplification. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Comparative and Absolute Measurements of 11 Inorganic Constituents of 38 Human Tooth Samples with Gamma-ray Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Samsahl, K [AB Atomenergi, Stockholm (Sweden); Soeremark, R [The Clinical Laboratory and the Dept. of Prosthetics of the Royal School of Dentistry, Stockholm (Sweden)

1961-12-15

The mean concentrations of the following elements have been simultaneously determined in normal human dentine, enamel and dental calculus with gamma-ray spectrometry; Na, P, Cl, Ca, Mn, Cu, Zn, Br, Sr, W and Au. In a typical run one sample each of dentine, enamel and dental calculus were irradiated together with standards of the elements to be determined in a thermal neutron flux of 2 x 10{sup 12} n/cm/sec for 20 hours. The chemical elements were separated into nine groups with ion exchange technique before the subsequent gamma spectrometric measurements. One man can manage the chemical separations and take the necessary gamma spectra from a run in one day. In a few samples of dentine, enamel and dental calculus which had been irradiated in a thermal neutron flux of 7 x 10{sup 13} n/cm/sec for one week the additional long lived trace elements were qualitatively determined Cr, Fe, Co, Rb, Ag, Sb, Cs and Ba.

Comparative and Absolute Measurements of 11 Inorganic Constituents of 38 Human Tooth Samples with Gamma-ray Spectrometry

International Nuclear Information System (INIS)

Samsahl, K.; Soeremark, R.

1961-12-01

The mean concentrations of the following elements have been simultaneously determined in normal human dentine, enamel and dental calculus with gamma-ray spectrometry; Na, P, Cl, Ca, Mn, Cu, Zn, Br, Sr, W and Au. In a typical run one sample each of dentine, enamel and dental calculus were irradiated together with standards of the elements to be determined in a thermal neutron flux of 2 x 10 12 n/cm/sec for 20 hours. The chemical elements were separated into nine groups with ion exchange technique before the subsequent gamma spectrometric measurements. One man can manage the chemical separations and take the necessary gamma spectra from a run in one day. In a few samples of dentine, enamel and dental calculus which had been irradiated in a thermal neutron flux of 7 x 10 13 n/cm/sec for one week the additional long lived trace elements were qualitatively determined Cr, Fe, Co, Rb, Ag, Sb, Cs and Ba

Neutron activation analysis of lipsticks using gamma-ray spectrometry

International Nuclear Information System (INIS)

Mirsa, G.; Mittal, V.K.

2004-01-01

Neutron activation analysis with gamma-ray spectrometry was used to measure the concentrations of various elements in lipsticks of popular Indian and foreign brands. The aim of the present work was to study the possibility of existence of trace elements in samples of lipsticks (the ingredients of which are mostly organic in nature) and to see whether trace elements could distinguish lipsticks of different Indian and foreign brands from the forensic point of view apart from their inter-se differentiation. In the different samples of lipsticks that were analysed the following elements were detected: Au, Ba, Br, Ca, Cs, Fe, Na, Ru, Sb, Sc, Ta, Yb, Zn, Rb and Se. It was found that inter-se differentiation of lipsticks was possible on the basis of concentrations of trace elements and their profile. Concentration of bromine in samples of lipsticks identified lipsticks of different Indian brands. Samples of lipsticks of Indian and foreign brands could be differentiated on the basis of concentrations of cesium, antimony and scandium which were found to be higher in foreign brands as compared to those in Indian brands. (authors)

Determination of U, Th and K in bricks by gamma -ray spectrometry, X-ray fluorescence analysis and neutron activation analysis

Czech Academy of Sciences Publication Activity Database

Bártová, H.; Kučera, Jan; Musílek, L.; Trojek, T.; Gregorová, E.

2017-01-01

Roč. 140, NOV (2017), s. 161-166 ISSN 0969-806X R&D Projects: GA MŠk LM2015056 Institutional support: RVO:61389005 Keywords : Gamma-ray spectrometry * neutron activation analysis * environmental dosimetry Subject RIV: CB - Analytical Chemistry , Separation OBOR OECD: Analytical chemistry Impact factor: 1.315, year: 2016

Recording {gamma} spectrometer with elimination of compton background; Spectrographe {gamma} enregistreur avec elimination du bruit de fond compton

Energy Technology Data Exchange (ETDEWEB)

Julliot, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

This instrument, derived from the recording {gamma} spectrograph, gives better definition of photoelectric peaks by elimination of pulses caused by {gamma} photons incompletely absorbed in the scintillator (Compton effect). This system uses an original method devised by Peirson: the spectrum, devoid of photoelectric peak, supplied by a detector equipped with an anthracene scintillator, is cut off from the spectrum provided by a conventional detector equipped with a Nal (T1) scintillator. The regulation of the mechanical system, detector support and source allows the detection yields to be adjusted. The electronic system is identical in presentation with that of the recording spectrograph. (author) [French] Cet appareil derive du spectrographe {gamma} enregistreur permet d'obtenir une meilleure definition des pics photoelectriques, par elimination des impulsions provenant des photons {gamma} incompletement absorbes dans le scintillateur (effet Compton). Cet ensemble met en oeuvre une methode originale due a Peirson: le spectre, depourvu de pic photoelectrique, fourni par un detecteur, equipe avec un scintillateur d'anthracene, est retranche du spectre donne par un detecteur classique, equipe avec un scintillateur de NaI (T1). Le reglage de l'ensemble mecanique, support des detecteurs et de la source, permet d'ajuster les rendements de detection. L'ensemble electronique se presente sous un aspect identique a celui du spectrographe enregistreur. (auteur)

Correcting the effects of the matrix using capture gamma-ray spectrometry: Application to measurement by Active Neutron Interrogation

International Nuclear Information System (INIS)

Baudry, G.

2003-11-01

In the field of the measurement of low masses of fissile material ( 235 U, 239 Pu, 241 Pu) in radioactive waste drums, the Active Neutron Interrogation is a non-destructive method achieving good results. It does however remain reliant upon uncertainties related to the matrix effects on interrogation and fission neutrons. The aim of this thesis is to develop a correction method able to take into account these matrix effects by quantifying the amount of absorbent materials (chlorine and hydrogen) in a 118- liter homogeneous matrix. The main idea is to use the gamma-ray spectrometry of gamma emitted by neutron captures to identify and quantify the composition of the matrix. An indicator from its chlorine content is then deduced in order to choose the calibration coefficient which best represents the real composition of the matrix. This document firstly presents the needs of control and characterization of radioactive objects, and the means used in the field of nuclear measurement. Emphases is put in particular on the Active Neutron Interrogation method. The matrices of interest are those made of light technological waste (density ≤ 0,4 g/cm 3 ) containing hydrogenated and chlorinated materials. The advantages of gamma-rays emitted by neutron captures for the determination of a chlorine content indicator of the matrices and the principles of the correction method are then explained. Measurements have been firstly realized with an existing Neutron Interrogation device (PROMETHEE 6). Such measurements have proven its inadequacy: no signal from the matrix hydrogen was detected, due to an intense signal from the polyethylene contained in some cell elements. Moreover, the matrix chlorine content appeared difficult to be measured. A new and specific device, named REGAIN and dedicated to active gamma-rays spectrometry, was defined with the Monte-Carlo N-Particle (MCNP) code. The experiments conducted with this new device made it possible to detect the hydrogen from the

Determination of the neutron activation profile of core drill samples by gamma-ray spectrometry.

Science.gov (United States)

Gurau, D; Boden, S; Sima, O; Stanga, D

2018-04-01

This paper provides guidance for determining the neutron activation profile of core drill samples taken from the biological shield of nuclear reactors using gamma spectrometry measurements. Thus, it provides guidance for selecting a model of the right form to fit data and using least squares methods for model fitting. The activity profiles of two core samples taken from the biological shield of a nuclear reactor were determined. The effective activation depth and the total activity of core samples along with their uncertainties were computed by Monte Carlo simulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determination of vanadium in titanate-based ferroelectrics by INAA with discriminating gamma-ray spectrometry

Czech Academy of Sciences Publication Activity Database

Kameník, Jan; Dragounová, K.; Kučera, Jan; Bryknar, Z.; Trepakov, Vladimír; Strunga, Vladimír

2017-01-01

Roč. 311, č. 2 (2017), s. 1333-1338 ISSN 0236-5731. [1st International Conference on Radioanalytical and Nuclear chemistry (RANC). Budapest, 10.04.2016-15.04.2016] R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk LM2015056 Institutional support: RVO:68378271 ; RVO:61389005 Keywords : Titanate-based ferroelectrics * Vanadium * INAA * discriminating gamma-ray spectrometry Subject RIV: CB - Analytical Chemistry, Separation; BM - Solid Matter Physics ; Magnetism (FZU-D) OBOR OECD: Analytical chemistry; Condensed matter physics (including formerly solid state physics, supercond.) (FZU-D) Impact factor: 1.282, year: 2016

Determination of natural radioactivity in building materials used in Tunisian dwellings by gamma ray spectrometry

International Nuclear Information System (INIS)

Hizem, N.; Fredj, A. B.; Ghedira, L.

2005-01-01

The radioisotopic content of 17 samples of natural and manufactured building materials collected in Tunisia have been analysed by using gamma spectrometry. From the measured gamma ray spectra, activity concentrations are determined for 232 Th, 226 Ra, 235 U and 40 K. The total effective dose and the activity concentration index are calculated applying the dose criteria recommended by the European Union for building materials. The results of 226 Ra, 232 Th and 40 K found in Tunisian building materials indicate that radium and thorium concentrations do not exceed 40 Bq kg -1 , but potassium concentration varies between 50 and 1215 Bq kg -1 . The total effective dose rates per person indoors are determined to be between 0.07 and 0.86 mSv y -1 . Only two materials exceed the reference level of 0.3 mSv y -1 . The activity concentration index is <1. (authors)

Prompt gamma-ray spectrometry for measurement of B-10 concentration in brain tissue and blood

International Nuclear Information System (INIS)

Nakagawa, Yoshinobu; Kitamura, Katsuji; Kobayashi, Toru; Matsumoto, Keizo; Hatanaka, Hiroshi.

1993-01-01

Boron-10 (B-10) concentration in the brain tissue and blood was measured continuously for 24 hours after injection of the B-10 compound in live rabbits using prompt gamma-ray spectrometry. Following injection of B-10 compound (Na 2 B 12 H 11 SH, 50mg/kg) dissolved in physiological saline, B-10 concentration was continuously measured in the brain tissue. Intermittently the concentration of B-10 in blood and cerebro-spinal fluid (CSF) was also measured. In 10 minutes after the injection of B-10 compound, the level of B-10 concentration reached the peak of 400-500 ppm in blood and 20-30 ppm in the normal brain tissue. In 60 minutes the level of B-10 concentration rapidly decreased and then a gradual decline was observed. The value was 15-30 ppm at 3 hours after injection, 5-10 ppm at 6 hours and 2-5 ppm at 24 hours in the blood. The concentration in the brain tissue was 3-8 ppm at 3 hours, 2-5 ppm at 6 hours and below 1.5 ppm at 24 hours. B-10 concentration in cerebro-spinal fluid was below 1 ppm. B-10 concentration was also measured in the brain tumor and blood in the human cases at boron neutron capture therapy (BNCT). These data studied by prompt gamma-ray spectrometry are very important and useful to decide the irradiation time. (author)

A Field Test of the New Portable Gamma Spectrometry System

Energy Technology Data Exchange (ETDEWEB)

Shin, Jung-Ki; Park, Uk Ryang; Park, Seunghoon; Chung, Heejun; Kwak, Sung-Woo [Korea Institute of Nuclear Non-proliferation and Control, Daejeon (Korea, Republic of); Kim, Yongkwn [NuCare Medical Systems, Inc., Incheon (Korea, Republic of)

2015-10-15

In order to perform a field test of the system, the measurement of U-235 enrichment for nuclear fuel pellets was conducted along with the IAEA Physical Inventory Verification (PIV) inspection at the KEPCO Nuclear Fuel (KNF). The enrichment value of U-235 was calculated based on the total counts of the 185.7 keV photopeak and compared with the reference line, drawn by certified sources. The goal of this study is to experimentally evaluate the system performance of the developed system. In this study, the new portable gamma spectrometry system showed a good linearity (R{sup 2}=1) but overestimated the enrichment values than IAEA inspection device. It could be caused by the stability of the new system since it found, right after this measurement, that the accuracy of the system gradually increases and becomes stable over time. Further steps will optimize the design parameter based on these results and repeat measurement with the same samples under the same environment.

Fisson product control by gamma spectrometry in Purex process solutions

International Nuclear Information System (INIS)

Goncalves, Maria A.; Matsuda, H.T.

1982-01-01

A radiometric method for fission product analysis by gamma spectrometry, to be applied for fission product control at an irradiated material processing facility, is described. Counting geometry was defined taking into account the activities of process solutions to be analysed, the remotely operated aliquotation device of the analytical cell and the available detection system. Natural and 19,91% enriched uranium samples were irradiated in order to simulate the composition of Purex process solutions. After a short decay time the samples were dissolved with HNO 3 and then conditioned in standard flasks with defined geometry. The spectra were obtained by a Ge(Li) semiconductor detector and analysed by the GELIGAM software system, using a floppy-disk connected to a PDP-11/05 computer. Libraries were prepared and calibrations were made with standard sources to fit the analysis of fission products in irradiated uranium solutions. It was possible to choose the best program to be used in routine analysis with the obtained data. (Author) [pt

Applications of gamma-ray spectrometry in real-time environmental monitoring

International Nuclear Information System (INIS)

Heath, R.L.; Dyer, N.C.

1974-01-01

The operation of large nuclear installations involves significant inventories of radioactive materials. Effective monitoring of effluent streams to permit evaluation of potential hazards which might result from discharge of radioisotopes is a requirement for safe operation of such facilities. The purpose of this paper is to present a summary of a program being conducted at the Idaho National Engineering Laboratory (INEL) to apply gamma-ray spectrometry to real-time isotopic monitoring of nuclear installations. The application of the lithium-drifted Ge spectrometer in the laboratory for isotopic assay is well established. To apply these techniques to routine on-line isotopic measurements requires the solution of a number of significant problems. These may be summarized as follows: the development of a remote pulse-height analyzer system; the development of adequate methods for analysis of pulse-amplitude spectra to permit isotopic assay and interpretation of results; and determination of basic nuclear decay data requirements for nuclides of interest to insure acceptance of isotopic assay results

Scintillation {gamma} spectrography. Physical principles. Apparatus. Operation; Spectrographie {gamma} a scintillations. Principes physiques. Appareillage. Utilisation

Energy Technology Data Exchange (ETDEWEB)

Julliot, C. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The scintillation detector forms the main part of the instrument used, the electronic unit presenting the results produced. After a brief description of the process of {gamma} photon absorption in the material, the particular case of NaI (T1), the scintillator used, is examined. The intensity of the scintillation caused by {gamma} ray absorption and the characteristics of the photomultiplier play a determining part in the energy resolution of the instrument. For the {gamma} recording spectrograph, we show to what extent the technique for using the electronic unit can modify the results. A detailed description is given of the activity measurement of a {gamma}-emitting radioelement by the spectrographic method. (author) [French] Dans l'appareillage utilise, le detecteur a scintillations constitue la piece maitresse, l'ensemble electronique presente les resultats issus du detecteur. Apres avoir brievement decrit le processus d'absorption des photons {gamma} dans la matiere, nous examinons le cas particulier du NaI(T1), le scintillateur utilise. L'intensite de la scintillation provoque par l'absorption des rayons {gamma} et les caracteristiques du photomultiplicateur jouent un role determinant dans la resolution en energie de l'appareil. Pour le spectrographe {gamma} enregistreur, nous indiquons dans quelle mesure la technique d'utilisation de l'ensemble electronique peut modifier les resultats. La-mesure de l'activite d'un radioelement emetteur {gamma} par spectrographie fait l'objet d'une description detaillee. (auteur)

Scintillation {gamma} spectrography. Physical principles. Apparatus. Operation; Spectrographie {gamma} a scintillations. Principes physiques. Appareillage. Utilisation

Energy Technology Data Exchange (ETDEWEB)

Julliot, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The scintillation detector forms the main part of the instrument used, the electronic unit presenting the results produced. After a brief description of the process of {gamma} photon absorption in the material, the particular case of NaI (T1), the scintillator used, is examined. The intensity of the scintillation caused by {gamma} ray absorption and the characteristics of the photomultiplier play a determining part in the energy resolution of the instrument. For the {gamma} recording spectrograph, we show to what extent the technique for using the electronic unit can modify the results. A detailed description is given of the activity measurement of a {gamma}-emitting radioelement by the spectrographic method. (author) [French] Dans l'appareillage utilise, le detecteur a scintillations constitue la piece maitresse, l'ensemble electronique presente les resultats issus du detecteur. Apres avoir brievement decrit le processus d'absorption des photons {gamma} dans la matiere, nous examinons le cas particulier du NaI(T1), le scintillateur utilise. L'intensite de la scintillation provoque par l'absorption des rayons {gamma} et les caracteristiques du photomultiplicateur jouent un role determinant dans la resolution en energie de l'appareil. Pour le spectrographe {gamma} enregistreur, nous indiquons dans quelle mesure la technique d'utilisation de l'ensemble electronique peut modifier les resultats. La-mesure de l'activite d'un radioelement emetteur {gamma} par spectrographie fait l'objet d'une description detaillee. (auteur)

Characterization of radioactive orphan sources by gamma spectrometry; Caracterizacion de fuentes huerfanas radiactivas por espectrometria gamma

Energy Technology Data Exchange (ETDEWEB)

Cruz W, H., E-mail: wcruz@ipen.gob.pe [Instituto Peruano de Energia Nuclear (PGRR/IPEN), Lima (Peru). Planta de Gestion de Residuos Radiactivos

2013-07-01

The sealed radioactive sources are widely applicable in industry. They must have a permanent control and must be registered with the Technical Office of the National Authority (OTAN). However, at times it has identified the presence of abandoned sealed sources unknown to the owner. These sources are called 'orphan sources'. Of course these sources represent a high potential risk because accidents can trigger dire consequences depending on your activity and chemical form in which it presents the radioisotope. This paper describes the process and the actions taken to characterize two orphan radioactive sources from the smelter a Aceros Arequipa. For characterization we used a gamma spectrometry system using a detector NaI(Tl) 3″ x 3″ with a multichannel analyzer Nucleus PCA-II. The radioisotope identified was cesium - 137 ({sup 137}Cs) in both cases. Fortunately, the sources maintained their integrity would otherwise have generated significant pollution considering the chemical form of the radioisotope and easy dispersion. (author)

Source term estimation based on in-situ gamma spectrometry using a high purity germanium detector

International Nuclear Information System (INIS)

Pauly, J.; Rojas-Palma, C.; Sohier, A.

1997-06-01

An alternative method to reconstruct the source term of a nuclear accident is proposed. The technique discussed here involves the use of in-situ gamma spectrometry. The validation of the applied methodology has been possible through the monitoring of routine releases of Ar-41 originating at a Belgian site from an air cooled graphite research reactor. This technique provides a quick nuclide specific decomposition of the source term and therefore will be have an enormous potential if implemented in nuclear emergency preparedness and radiological assessments of nuclear accidents during the early phase

A New Method for Processing Airborne Gamma Ray Spectrometry Data for Mapping Low Level Contaminations

DEFF Research Database (Denmark)

Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim

1999-01-01

A new technique for processing airborne gamma ray spectrometry data has been developed. It is based on the noise adjusted singular value decomposition method introduced by Hovgaard in 1997. The new technique opens for mapping of very low contamination levels. It is tested with data from Latvia...... where the remaining contamination from the 1986 Chernobyl accident together with fallout from the atmospheric nuclear weapon tests includes Cs-137 at levels often well below 1 kBq/m(2) equivalent surface contamination. The limiting factors for obtaining reliable results are radon in the air, spectrum...

Use of a Shielded High Resolution Gamma Spectrometry System to Segregate LLW from Contact Handleable ILW Containing Plutonium - 13046

Energy Technology Data Exchange (ETDEWEB)

Lester, Rosemary; Wilkins, Colin [Canberra UK Ltd, Unit 1 B528.1, Harwell Science Campus, Oxfordshire OX11 0DF (United Kingdom); Chard, Patrick [Canberra UK Ltd, Forss Business and Technology park, Thurso, Caithness KW14 7UZ (United Kingdom); Jaederstroem, Henrik; LeBlanc, Paul; Mowry, Rick [Canberra Industries, Inc., 800 Research Parkway, Meriden, Connecticut, 06450 (United States); MacDonald, Sanders; Gunn, William [Dounreay Site Restoration Limited, Dounreay, Thurso, Caithness, KW14 7TZ (United Kingdom)

2013-07-01

Dounreay Site Restoration Limited (DSRL) have a number of drums of solid waste that may contain Plutonium Contaminated Material. These are currently categorised as Contact Handleable Intermediate Level Waste (CHILW). A significant fraction of these drums potentially contain waste that is in the Low Level Waste (LLW) category. A Canberra Q2 shielded high resolution gamma spectrometry system is being used to quantify the total activity of drums that are potentially in the LLW category in order to segregate those that do contain LLW from CHILW drums and thus to minimise the total volume of waste in the higher category. Am-241 is being used as an indicator of the presence of plutonium in the waste from its strong 59.54 keV gamma-ray; a knowledge of the different waste streams from which the material originates allows a pessimistic waste 'fingerprint' to be used in order to determine an upper limit to the activities of the weak and non-gamma-emitting plutonium and associated radionuclides. This paper describes the main features of the high resolution gamma spectrometry system being used by DSRL to perform the segregation of CHILW and LLW and how it was configured and calibrated using the Canberra In-Situ Object Counting System (ISOCS). It also describes how potential LLW drums are selected for assay and how the system uses the existing waste stream fingerprint information to determine a reliable upper limit for the total activity present in each measured drum. Results from the initial on-site commissioning trials and the first measurements of waste drums using the new monitor are presented. (authors)

Equipment and applications for gamma spectrometry

International Nuclear Information System (INIS)

Hemingway, J.D.

1986-01-01

In this article the theoretical aspects of gamma spectroscopy are discussed. Coaxial germanium detectors and planar detectors are described. Applications of gamma spectroscopy to the detection of the exposure of a population to naturally occuring radioactive gases and their daughter products; the accumulation of iodine isotopes in the thyroid and measuring the quantity of 239 Pu in the lungs are discussed. (UK)

Development and calibration automatic equipment's measuring in real time of the environmental radioactivity by gamma spectrometry

International Nuclear Information System (INIS)

Casanovas, R.; Morant, J. J.; Salvado, M.

2013-01-01

In this paper, we describe the general aspects of the implementation of gamma spectrometry in water, as well as the development of two measuring devices based on this technique: aerosol monitor (RARM-F) and a monitor direct measurement (RARMD2) , both patent applications. Furthermore, they described in detail the aspects of calibration of equipment, which has been made by combining experimental measurements with Monte Carlo simulations. (Author)

Radon fixation for determination of 224Ra, 226Ra and 228Ra via gamma-ray spectrometry

International Nuclear Information System (INIS)

Herranz, M.; Idoeta, R.; Abelairas, A.; Legarda, F.

2006-01-01

The aim of this work is the improvement of the procedure for the determination of radium isotopes activities in water, which is done through radiochemical separation and subsequent gamma-ray spectrometry. In addition, radon gas retention is studied using different activated carbon materials. The results of the IAEA Proficiency test: 'Determination of radium and uranium radionuclides in water' of December 2002 [IAEA, 2003. Analytical quality control services: determination of radium and uranium radionuclides in water. Preliminary Report, Seibersdorf] are considered for this work

Extraction of gold and mercury from sea water with bismuth diethyldithiocarbamate prior to neutron activation-. gamma. -spectrometry

Energy Technology Data Exchange (ETDEWEB)

Yu, J.C.; Lo, J.M.; Wai, C.M. (Idaho Univ. Moscow (USA). Dept. of Chemistry)

1983-11-01

Gold and mercury in sea water can be selectively extracted by bismuth diethyldithiocarbamate into chloroform at pH <= 1. The matrix species and many other trace elements in the system are effectively removed during extraction. When neutron activation-..gamma..-spectrometry is used, the detection limits for gold and mercury are 0.001 and 0.01 ..mu..g l/sup -1/, respectively. The relative precision is 9% for gold and 13% for mercury.

Improvements on Low Level Activity Gamma Measurements and X-ray Spectrometry at the CEA-MADERE Measurement Platform

OpenAIRE

Sergeyeva Victoria; Domergue Christophe; Destouches Christophe; Girard Jean Michel; Philibert Hervé; Bonora Jonathan; Thiollay Nicolas; Lyoussi Abdallah

2016-01-01

The CEA MADERE platform (Measurement Applied to DosimEtry in REactors) is a part of the Instrumentation Sensors and Dosimetry Laboratory (LDCI). This facility is dedicated to the specific activity measurements of solid and radioactive samples using Gamma and X-ray spectrometry. MADERE is a high-performance facility devoted to neutron dosimetry for experimental programs performed in CEA and for the irradiation surveillance programmes of PWR vessels. The MADERE platform is engaged in a continuo...

Analysis of spectra from portable handheld gamma-ray spectrometry for terrain comparative assessment

International Nuclear Information System (INIS)

Dias, Flávio; Lima, Marco; Sanjurjo-Sánchez, Jorge; Alves, Carlos

2016-01-01

Geological characteristics can have impacts on societal development by, e.g., geotechnical issues and radiological hazard levels. Due to urban sprawl, there is an increasing need for detailed geological assessment. In this work are analysed data from portable handheld gamma-ray spectra (K, eU and eTh) obtained in granitic and Silurian metaclastic outcrops as well as in an profile, roughly N–S, on soil covered terrains transecting a mapped contact between these rock types (the profile's northern extremity is at locations mapped as granite). Estimations from gamma-ray spectra were studied by univariate and multivariate analyses. K, eU and eTh values were higher on granite in relation to Silurian metaclastic rocks. The northern extremity of the profile showed clearly higher contents of eTh and this contrast was supported by univariate statistical tools (normality plot and Wilk–Shapiro test; boxplots). A ternary plot with the contribution of the elements to gamma-ray absorbed dose showed the separation of granite from Silurian metaclastic rocks with the former being nearer the eTh vertex. The points in the northern extremity of the profile are nearer the eTh vertex than the other points on the profile. These visual suggestions were supported by hierarchical cluster analysis, which was able to differentiate between granite and metaclastic outcrops and separate portions of the profile located on different terrains. Portable gamma-ray spectrometry showed, hence, the potential to distinguish granite and metaclastic terrains at a scale useful for engineering works. These results can also be useful for a first comparative zoning of radiological hazards (which are higher for granite). - Highlights: • Contents of K, eU and eTh were estimated by portable gamma-ray spectra. • Spectra were acquired on a profile across a soil covered granite/metaclastic contact. • Spectra were also collected on granite and Silurian metaclastic outcrops. • Obtained estimations were

Natural radioactivity in extreme south of Bahia, Brazil, using gamma-ray spectrometry

International Nuclear Information System (INIS)

Vasconcelos, Danilo C.; Oliveira, Arno H.; Silva, Mario R.S.; Penna, Rodrigo; Santos, Talita O.; Pereira, Claubia; Rocha, Zildete; Menezes, Maria Angela B.C.

2009-01-01

The concentrations activity of natural radionuclides in beach sand in extreme south of Bahia-Brazil was measured using gamma-ray spectrometry. The activity concentrations of 226 Ra, 232 Th and 40 K in beach sand ranged from 14.5 to 8,318.4, 20.5 to 18,450.0, 15.4 to 3,109.0 Bq/kg, with a mean value of 1,078.2, 2,429.6, and 417.0 Bq/kg respectively. The values of radiation hazard indexes in sands of Alcobaca, Caraiva and Cumuruxatiba are higher than the limits preconized by Beretka and Mathew. The use of these sands may be not safe in building constructions. The results show that the absorbed dose rates range from 20.4-15,116.6 nGy/h with mean value of 1762.7. The highest value of gamma dose rates among the studied beaches was found in Cumuruxatiba (15,116.6 nGy/h). The annual effective dose varied between 0.028 and 18.539 mSv/year, with a mean of 2.162 mSv/year. Values of Alcobaca, Trancoso, Caraiva and Cumuruxatiba are higher than the worldwide average for outdoor annual effective dose, 0.07 mSv/year. (author)

Burn up determination of IEAR-1 fuel elements by non destructive gamma ray spectrometry method

International Nuclear Information System (INIS)

Soares, A.J.

1977-01-01

Measurement of nuclear fuel burn up by non destructive gamma ray spectrometry is discussed, and results of such measurements, made at the Instituto de Energia Atomica (IEA), are given. Specifically, the burn up of an MTR (Material Testing Reactor) fuel element removed from the IEAR-1 swimming pool reactor in 1958 is evaluated from the measured Cs-137 activity, which gives a single 661,6 keV gamma ray. Due to the long decay time of the test element, no other fission decay product activity could be detected. Analysis of measurements, made with a 3'' x 3'' NaI(Tl) detector at 330 distinct points of the element, showed the total burn up to 3.3 +- -+ 0.8 mg. This is in agreement with a calculated value. As the maximum temperature of IEAR-1 fuel elements is of the order of 40 0 C, migration effects of Cs-137 was not considered, this being significant only at fuel temperature in excess of 1000 0 C [pt

Emergency response exercise of laboratories equipped with gamma spectrometry

International Nuclear Information System (INIS)

Mala, H.; Jezkova, T.; Rulik, P.; Beckova, V. et al.

2014-01-01

Seven laboratories equipped with semiconductor gamma spectrometry (HPGe detectors) are currently included in the Radiation Monitoring Network (RMN) in the Czech Republic. These laboratories have more than 30 spectrometric chains and approximately 20 'experts' and 70 'users' who would guarantee measurements during the radiological emergency (RE). The emergency exercise was carried out in 5 of them in 2014 (in 4 of them also in 2013). The aim was to test repeatedly their capacity in existing technical facilities and with current staff in the event of a RE and identify problems (bottlenecks) in the whole process from receipt of samples to entering the results into the central database of RMN. Duration of the exercise was 12 hours, due to the shortage of staff; work in one 12-hour shift is presumed during a RE, which the laboratories should be able to provide for 14 days. These exercise samples covered a wide range of commodities that would probably come to the laboratories during the RE (aerosol filters, sorbents for sorption of gaseous forms of iodine, fallout, surface and drinking waters, food chain components and soils). Some of the samples were previously spiked with 85 Sr, 88 Y and 40 K (in the exercise these nuclides represented actual contamination that would occur in RE); liquid samples were spiked with 85 Sr and 88 Y and bulk materials with 40 K.During the exercise almost 800 samples were analysed; in addition, the automatic gamma counter (GA) in Prague laboratory measured other 90 samples automatically during the night (samples were prepared during the day-shift). On the basis of the results the total measuring capacity of the laboratories of RMN CR was estimated at about 1300 samples per day. (authors)

Use of airborne gamma-ray spectrometry for kaolin exploration

Science.gov (United States)

Tourlière, B.; Perrin, J.; Le Berre, P.; Pasquet, J. F.

2003-08-01

Airborne gamma-ray spectrometry was used to define targets with kaolin potential in the Armorican Massif of Brittany, France. This exploration method is based on the principle that kaolinite, an aluminosilicate clay mineral constituting kaolin, is formed by the hydrolysis of potash feldspar with the elimination of potassium. Therefore, potassium contrast between favourable host-rock such as a leucogranite and kaolin occurrence is likely a significant pathfinder. As the relationship between the potassium-40 recorded by an airborne gamma-ray spectrometer and total potassium is constant, such data provide us a direct measurement of the potassium content of the ground flown over. Our study tested this by calculating, for each geological unit, the difference between the measured and average potassium content calculated for a given geological formation. The study was based on (i) a recent (1998) high-definition airborne geophysical survey over the Armorican Massif undertaken on behalf of the French Government, and (ii) new geological compilation maps covering the same region. Depleted zones, where the measured potassium is less than the average potassium content calculated target areas with high potential of containing kaolin, provided that the unit was originally rich in potash feldspar. By applying this method to the entire Armorican Massif, it was possible to identify 150 potassium-depleted zones, including 115 that were subjected to rapid field checks and 36 that contained kaolin (21 new discoveries). This method, which is both safe for the environment and easy to use, is therefore a good tool for rapidly defining targets with kaolin potential at a regional scale. The method may also have possibilities in exploring for other types of deposit characterised by an enrichment or depletion in U, K and/or Th.

Solid state scintillators for gamma spectrometry

International Nuclear Information System (INIS)

La Mela, G.; Torrisi, M.

1991-01-01

Using different scintillator crystals, measurements of energy resolution and detection efficiency have been performed to detect gamma rays of energy ranging between 500 en 1550 KeV. This investigation is devoted to characterize the best systems to detect photons coming from positron annihilation processes, such as a PET apparatus where the medical image is the final aim of the investigation, and gamma emission from radioisotopes of biomedical interest

Critical review of gamma spectrometry detection approaches for in-plant surface deposition monitoring

Energy Technology Data Exchange (ETDEWEB)

Gregorich, Carola [Nuclear Fuels and Chemistry at the Electric Power Research Institute, Palo Alto, CA 94304, (United States)

2015-07-01

Surface deposition of activated corrosion product on oxide layers of light-water reactor primary system components is the primary source for ex-core radiation fields and personnel radiation exposure. Understanding the deposition mechanism and what factors influence the deposition and release behaviors are crucial for developing effective radiation field reduction measures. One of the available tools to assess the surface deposition is in-plant gamma spectrometry, which has been performed for several decades using either sodium iodide (NaI) or high-purity germanium (HPGe) detectors. Lately, the much more mobile cadmium-zinc-telluride (CZT) detectors are increasingly employed by stations because of their ease in use and handling. However, all of these gamma detectors face the same challenges; namely large-geometry samples of inconsistent sample compositions and sometimes gaps in the information necessary to establish proper efficiency calibrations. This paper reviews current measurements and efficiency calibration approaches taken in the industry. The validity of the measurement results and the feasibility of the data's use in understanding source term behavior is examined. Suggestions are made for the development of a more robust deposit characterization and radiation field monitoring program. (authors)

Study of the artificial radioactivity of the marine medium using gamma spectrometry (1962-1966)

International Nuclear Information System (INIS)

Chesselet, R.

1969-01-01

The results described in this study are relative to the artificial radioactivity of such elements as zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 and praseodymium-144 which were present in the atmospheric fallout between 1962 and 1964, and their incidence in superficial marine waters. Various physical, chemical or biological processes are studied by a high sensitivity gamma ray spectrometry technic, using those radioelements as 'tracers'. The change of state in sea water of an important fraction (about 50 per cent) of the radioactive particles going into the soluble phase - this phenomenon was not expected for those radioelements - controls the processes of accumulation in the planktonic biomass and the diffusion towards deeper waters. On the other hand, an 'in situ' spectrometry method is described. It enables the direct measurement in the sea of very low concentrations of some gamma ray emitters. The application of this method has made possible to carry out numerous observations in the surface waters of the Western Mediterranean sea and in the Bay of Biscay. It is shown that the mixing depth is closely connected to the depth of the thermocline. An accumulation process at this level is observed. The diffusion coefficients are similar to the thermal turbulent coefficient. The existence during several months of 'compartments' is established for the surface waters of the Bay of Biscay. From the establishment of the budget of fall-out, a comparative study shows that the rate of radioactive fallout on the maritime zone considered is always two to three times higher than on the neighbouring continental regions. Several explanations of this phenomenon are discussed. (author) [fr

Gamma-ray spectrometry laboratory and in situ: developments and environmental applications

International Nuclear Information System (INIS)

Gasser, Estelle

2014-01-01

Gamma-ray spectrometry enables determining all γ-ray emitters in a sample with a single measurement. Self-absorption of γ-rays in samples is manifest by a loss or a gain of pulses that results in a poor estimation of the counting efficiency. To characterize a new counting geometry improvements of the existing set-up were made with MCNPX simulations. With the new geometry we could specify absorbed and annual effective doses as well as dose conversion factors for the natural radioisotopes of several building materials and soil samples. Simulations show the influence of detection limits of γ-radiation on dose conversion factors and the need for updating these factors. γ-ray measurements of soil in situ require different counting efficiencies simulated by MCNPX for a semi-infinite source. Two in-situ soil analyses were made, one around a nuclear power and the other for a private company. (author)

Report of the Department of Energy, Office of Environmental Management, Gamma Spectrometry Data Validation Program

International Nuclear Information System (INIS)

Decker, K.; Sanderson, C.G.; Greenlaw, P.

1996-11-01

This report represents the results of analyses received on or before August 15, 1996 for the first annual Gamma Spectrometry Data Validation Program (May 1996) designed to assess the capability of DOE laboratories and DOE contractors in performing routine gamma spectra analyses. Data reduction of gamma spectra are normally performed with computer codes supplied by commercial manufacturers or are developed in house. Earlier evaluations of commercial codes gave spurious results for complex spectrum. A calibration spectrum, a background spectrum and three sample spectra of increasing complexity were included for each format. The calibration spectrum contained nuclides covering the energy range from 59.5 keV to 1836 keV. The first two samples contained fallout nuclides with halflives of over 30 days. Naturally occurring nuclides were also present. The third sample contained both short and long lived fission product nuclides. The participants were asked to report values and uncertainties as Becquerel per sample with no decay correction. Sixteen software packages were evaluated. In general, the results do not appear to be dependent on the software used. Based on the control limits established for the Program for the three sample spectra, 62%, 63% and 53%, respectively, of the reported results were evaluated as acceptable

A self-sufficient and general method for self-absorption correction in gamma-ray spectrometry using GEANT4

International Nuclear Information System (INIS)

Hurtado, S.; Villa, M.; Manjon, G.; Garcia-Tenorio, R.

2007-01-01

This paper presents a self-sufficient and general method for measurement of the activity of low-level gamma-emitters in voluminous samples by gamma-ray spectrometry with a coaxial germanium detector. Due to self-absorption within the sample, the full-energy peak efficiency of low-energy emitters in semiconductor gamma-spectrometers depends strongly on a number of factors including sample composition, density, sample size and gamma-ray energy. As long as those commented factors are well characterized, the influence of self-absorption in the full-energy peak efficiency of low-energy emitters can be calculated using Monte Carlo method based on GEANT4 code for each individual sample. However this task is quite tedious and time consuming. In this paper, we propose an alternative method to determine this influence for voluminous samples of unknown composition. Our method combines both transmission measurements and Monte Carlo simulations, avoiding the application of Monte Carlo full-energy peak efficiency determinations for each individual sample. To test the accuracy and precision of the proposed method, we have calculated 210 Pb activity in sediments samples from an estuary located in the vicinity of several phosphates factories with the proposed method, comparing the obtained results with the ones determined in the same samples using two alternative radiometric techniques

Decision Threshold and Detection Limit in Spectrometric Measurements. Part 1: Application to Gamma Spectrometry; Umbral de Decision y Limite de Deteccion en Medidas Espectrometricas. Parte 1: Aplicacion a la Espectrometria Gamma

Energy Technology Data Exchange (ETDEWEB)

Perez, C.; Gasco, C.; Lopez, M.A.

2010-03-03

This report summarised the author's lecture of the advanced gamma spectrometry course organised by CIEMAT. The characteristic limits determination in gamma spectrometry generally is obtained through the programming that the trade marks offers to the client with the objective of the automatic calculation of the activity concentrations existing in a sample. In this report, the examples shown in the ISO 11929 standard are compared to the programming realised by Genie 2k for determining characteristic limits. The main difference of both is located in the uncertainty calculations due to the efficiency calibration that is considered by ISO and not by Genie 2K. Through implementation in the software developed by trade marks will be possible to introduce this uncertainty and to assimilate to the calculation done by ISO 11929. In the second part of this report will be analyzed the more complicated samples of this application as counting in a whole body counter (following ISO-28218 about Performance Criteria for radio bioassay), multiplet, overlapping, addition of several peaks for obtaining the activity concentration, etc. (Author) 19 refs.

A comparison of four aerial radiological surveys of Par Pond and the surrounding area, Savannah River Site, Aiken, South Carolina

International Nuclear Information System (INIS)

Feimster, E.L.

1993-09-01

A series of gamma radiation surveys was conducted over Par Pond at the Savannah River Site (SRS) in August 1993, October 1991, and August 1992 as part of an effort to monitor the radiological changes around Par Pond as its water level was lowered. The results of an April 1989 survey, which was about one-half the area of those surveys listed above, were used as baseline data for the comparison. Gamma energy spectrum analysis revealed that the only man-made gamma ray emitter detected during the four surveys in the Par Pond area was cesium-137. The comparisons revealed that: (1) significant change in the radiological environment occurred along the Par Pond shoreline as the water levels were lowered, (2) the activity in Lower Three Runs Creek varied slightly as the level/flow rate changed during the pumping process, (3) minor changes occurred in areas adjacent to the Par Pond, and (4) little or no change occurred between surveys in the spatial distribution or kind of sources detected. All changes were directly related to the moisture variations (Par Pond water lowering, rainfall, waterway flow rates) between the survey periods. The distribution, kind, and activity of sources detected beyond the pond bed were consistent between surveys. 60 figs., 14 tabs

Constrains in gamma spectrometry analysis of fallout 137Cs in coastal marine environment of Arabian sea in India

International Nuclear Information System (INIS)

Sartandel, S.J.; Jha, S.K.; Puranik, V.D.

2012-01-01

In this study, an accurate faster gamma spectrometry method for measuring the low level activity concentrations of 137 Cs using in situ pre-concentration technique on copper ferrocyanide cartridge was standardized. Due to unavailability of reference standard in the copper ferrocyanide matrix, efficiency calibration curves were plotted using RGU and RGTh reference standards. To harmonize the difference in density of standard and sample the required density correction factors for photo peak efficiency were generated. The in situ pre-concentration technique followed by gamma-ray spectrometry was applied for activity determination in surface seawater from eight locations in the coastal marine environment of Arabian Sea. The mean activity concentration of 137 Cs ranged between 0.71 and 0.91 Bq/m 3 . Higher activity concentrations were observed at location with latitude, longitude of 21.6 deg N, 69.57 deg E as compared to concentration observed at location with latitude, longitude 16.98 deg N, 73.25 deg E. The observed concentrations were found to be in range of data reported in Asia-Pacific Marine radioactive database (ASPARMARD). The results will fill up the gaps in the existing database. The generated data will be useful for monitoring fresh input of anthropogenic radionuclide into coastal marine environment for post Fukushima environmental assessment. (author)

Detection limits should be a thing of the past in gamma-ray spectrometry in general as well as in neutron activation analysis

NARCIS (Netherlands)

Blaauw, Menno

2016-01-01

In gamma-ray spectrometry with high-resolution detectors, full-energy peaks are often to be detected by a peak-search algorithm, with a threshold for detection. Detection limits can be derived from this. Detection limits are often computed along with measured activities or concentrations. When an

Investigation by gamma-ray spectrometry and INAA of radioactivity impact on phosphate fertilizer plant environment

International Nuclear Information System (INIS)

Pantelica, A.; Companis, I.; Georgescu, I. I.; Pincovshi, E.

2006-01-01

The radioactive polluting effect of a phosphate fertilizer plant on the environment was investigated by gamma-ray spectrometry and neutron activation analysis (INAA). The hazards could arise from industrial plants using raw phosphate materials to prepare fertilizers for agricultural purposes due to the phosphate rock which, depending on the type and geographical zone of provenance may contain rather large amounts of uranium. The fertilizer plant under study is situated about 4 km from the town of Turnu Magurele, on the left bank of the Danube River in Romania. The main by-products of the factory are: nitro phosphate type fertilizers (NP, NPK), Ammonia, Nitric acid, Ammonium nitrate, Urea, Sulfuric acid, Phosphoric acid, Sodium fluorosilicate and Aluminum sulfate. Gamma-ray spectrometry was used to determine activity concentrations of naturally occurring radionuclides ( 2 26Ra, 2 35U, 2 38U, 2 32Th, and 4 0K), as well as 1 37Cs man-made radionuclide in surface soils collected from semicircular areas within radii of 0.5 and 15 km of the plant; in addition, different NPK type fertilizers and phosphate rocks were investigated. The samples (mass of about 100-g each) were kept tightly closed for one month to permit 2 26Ra to establish radioactive equilibrium with its decay products. This method makes it possible to assess U, Th, and K contents in samples by measuring 2 38U and 2 32Th (in equilibrium with their radioactive daughters) and 4 0K radioactivity, taken into account that 1 g of U, Th and K yield 1 2358 Bq 2 38U, 569 Bq 2 35U, 4057.2 Bq 2 32Th and 33.11 Bq 4 0K, respectively. The spectrometrical chain was based on a HPGe (EG and G Ortec) detector of 30 % relative efficiency and 2.1 keV resolution at 1332 keV of 6 0Co. INAA technique (neutron irradiation at TRIGA reactor of SCN Pitesti) was used to determine macro, micro and trace elements in samples collected from both technological shops of the factory (air dust and drinking tap water) and its surroundings

Spatially-Dependent Measurements of Surface and Near-Surface Radioactive Material Using In situ Gamma Ray Spectrometry (ISGRS) For Final Status Surveys

International Nuclear Information System (INIS)

J. A. Chapman, A. J. Boerner, E. W. Abelquist

2006-01-01

In-situ, high-resolution gamma-ray spectrometry (ISGRS) measurements were conducted at the Oak Ridge Institute for Science and Education ORISE field laboratory in Oak Ridge, Tennessee. The purpose of these tests was to provide analytical data for assessing how 'fit for use' this technology is for detecting discrete particles in soil

Spatially-Dependent Measurements of Surface and Near-Surface Radioactive Material Using In situ Gamma Ray Spectrometry (ISGRS) For Final Status Surveys

Energy Technology Data Exchange (ETDEWEB)

J. A. Chapman, A. J. Boerner, E. W. Abelquist

2006-11-15

In-situ, high-resolution gamma-ray spectrometry (ISGRS) measurements were conducted at the Oak Ridge Institute for Science and Education (ORISE) field laboratory in Oak Ridge, Tennessee. The purpose of these tests was to provide analytical data for assessing how “fit for use” this technology is for detecting discrete particles in soil.

Optimization of measure parameters for an X- and gamma-ray spectrometry portable system

International Nuclear Information System (INIS)

Fernandes, Jaquiel S.; Appoloni, Carlos R.

2008-01-01

In order to optimize the use of a system for in situ gamma (γ)- and X-ray spectrometry composed of a 3x3x1 mm 3 Cadmium Telluride (CdTe) detector with respect to the detection of low-activity radioactive sources, a two level factorial planning was accomplished, involving three factors that could modify the system response. This planning was made with a 137 Cs punctual source, analyzing the X-ray energy line of 32 keV from 137m Ba. It was concluded that, for the system optimization, the best configuration for the involved parameters was to work with the detector at temperature of -22 o C, shaping time of 3 μs and rise time discrimination (RTD) with value 3

Calculation of “LS-curves” for coincidence summing corrections in gamma ray spectrometry

Science.gov (United States)

Vidmar, Tim; Korun, Matjaž

2006-01-01

When coincidence summing correction factors for extended samples are calculated in gamma-ray spectrometry from full-energy-peak and total efficiencies, their variation over the sample volume needs to be considered. In other words, the correction factors cannot be computed as if the sample were a point source. A method developed by Blaauw and Gelsema takes the variation of the efficiencies over the sample volume into account. It introduces the so-called LS-curve in the calibration procedure and only requires the preparation of a single standard for each sample geometry. We propose to replace the standard preparation by calculation and we show that the LS-curves resulting from our method yield coincidence summing correction factors that are consistent with the LS values obtained from experimental data.

Study of the parabolic-spherical shape on the energy resolution in gamma spectrometry

International Nuclear Information System (INIS)

Silva, Joao Carlos Pereira da

1997-01-01

In gamma spectrometry, the energy resolution is an important parameter. This parameter measures the capability of the system to separate two photopeaks that are together. Scintillation systems have various factors that affect the energy resolution: energy deposition, light emission, light collection and electric signal processing. Light collection depended on the mechanisms of light transport until light strikes on the photocathode. In this trajectory the light losses energy by attenuation and refractions on the surfaces. In order to minimize these effects, a parabolic-spherical shape is proposed. The energy resolutions of hemispherical and parabolic-spherical shapes were measured. The results show a better resolution for the new shape, about 33% for Compton edge due to a 137 Cs radioactive source. (author)

Gamma-ray spectrometry of ultra low levels of radioactivity within the material screening program for the GERDA experiment.

Science.gov (United States)

Budjás, D; Gangapshev, A M; Gasparro, J; Hampel, W; Heisel, M; Heusser, G; Hult, M; Klimenko, A A; Kuzminov, V V; Laubenstein, M; Maneschg, W; Simgen, H; Smolnikov, A A; Tomei, C; Vasiliev, S I

2009-05-01

In present and future experiments in the field of rare events physics a background index of 10(-3) counts/(keV kg a) or better in the region of interest is envisaged. A thorough material screening is mandatory in order to achieve this goal. The results of a systematic study of radioactive trace impurities in selected materials using ultra low-level gamma-ray spectrometry in the framework of the GERDA experiment are reported.

Fission products control by gamma spectrometry in purex process solutions

International Nuclear Information System (INIS)

Goncalves, Maria Augusta

1982-01-01

This paper deals with a radiometric method for fission products analysisby gamma spectrometry. This method will be applied for fission productscontrol at the irradiated material processing facility, under construction inthe Instituto de Pesquisas Energeticas e Nucleares, SP, Brazil. Countinggeometry was defined taking into account the activities of process solutionsto be analysed, the remotely operated aliquotation device of analytical celland the available detection system. Natural and 19,91% enriched uraniumsamples were irradiated at IEAR-1 reactor in order to simulate thecomposition of Purex process solutions. After a short decay time, the sampleswere dissolved with HNO 3 and then, conditioned in standard flasks withdefined geometry. The spectra were obtained by a Ge(Li) semiconductordetector and analysed by the GELIGAM software system, losing a floppy-diskconnected to a PDP-11/05 computer. Libraries were prepared and calibrationswere made with standard sources to fit the programs to the analysis offission products in irradiated uranium solutions. It was possible to choosethe best program to be used in routine analysis with the obtained data.(author)

Medium-term experiences with in-situ gamma-spectrometry of the primary loop transport processes at Paks NPP

International Nuclear Information System (INIS)

Raics, P.; Sztaricskai, T.; Szabo, J.; Szegedi, S.

2001-01-01

Surface activity of 15 corrosion/erosion and fission products was determined by in-situ gamma-spectrometry for 2-2 locations on the hot and cold legs of each loop, respectively. Gamma-dosimetry in the assay points was performed. Activity profiles of ion exchange columns were analyzed. Combined measurements along the steam generators completed the characterization of the primary circuits. Most of this technique was regularly included into all maintenance periods. Data evaluation was performed for the surface contaminations as well as coolant activities and reactor operation features for years 1985-2001. Trends and tendencies were investigated in the time behavior of the specific activities. Asymmetry in the surface contamination at the primary loop points, cold-leg activity inversion, water chemistry effects, isotope selectivity were observed. Correlations in different parameters have been calculated and analyzed. (R.P.)

In situ gamma spectrometry development for site mapping

International Nuclear Information System (INIS)

Panza, F.

2012-01-01

The high-resolution gamma spectrometry currently provides a powerful analytical tool for performing environmental measurements. In the context of radiological characterization of a site (natural or artificial radioactivity) and for the dismantling of nuclear installations, mapping of radionuclides is an important asset. The idea is to move a HPGe spectrometer to study the site and from nuclear and position data, to identify, to locate and to quantify the radionuclides present in the soil. The development of this tool follows an intercomparison (ISIS 2007) where an intervention/crisis exercise showed the limits of current tools. The main part of this research project has focused on mapping of nuclear data. Knowledge of the parameters of an in situ spectrum helped to create a simulator, modeling the response of a spectrometer moving over contaminated soil. The simulator itself helped to develop algorithms for mapping and to test them in extreme situations and not realizable. A large part of this research leads to the creation of a viable prototype providing real-time information concerning the identity and locality as possible radionuclides. The work performed on the deconvolution of data can make in post processing a map of the activity of radionuclide soil but also an indication of the depth distribution of the source. The prototype named OSCAR was tested on contaminated sites (Switzerland and Japan) and the results are in agreement with reference measurements. (author)

Qualitative and quantitative validation of the SINBAD code on complex HPGe gamma-ray spectra

Energy Technology Data Exchange (ETDEWEB)

Rohee, E.; Coulon, R.; Normand, S.; Carrel, F. [CEA, LIST, Laboratoire Capteurs et Architectures electroniques, F-91191 Gif-sur-Yvette, (France); Dautremer, T.; Barat, E.; Montagu, T. [CEA, LIST, Laboratoire Modelisation, Simulation et Systemes, F-91191 Gif-sur-Yvette, (France); Jammes, C. [CEA/DEN/SPEx/LDCI, Centre de Cadarache, F-13109 Saint-Paul-lez-Durance, (France)

2015-07-01

Radionuclides identification and quantification is a serious concern for many applications as safety or security of nuclear power plant or fuel cycle facility, CBRN risk identification, environmental radioprotection and waste measurements. High resolution gamma-ray spectrometry based on HPGe detectors is a performing solution for all these topics. During last decades, a great number of software has been developed to improve gamma spectra analysis. However, some difficulties remain in the analysis when photoelectric peaks are folded together with a high ratio between theirs amplitudes, when the Compton background is much larger compared to the signal of a single peak and when spectra are composed of a great number of peaks. This study deals with the comparison between conventional methods in radionuclides identification and quantification and the code called SINBAD ('Spectrometrie par Inference Non parametrique Bayesienne Deconvolutive'). For many years, SINBAD has been developed by CEA LIST for unfolding complex spectra from HPGe detectors. Contrary to conventional methods using fitting procedures, SINBAD uses a probabilistic approach with Bayesian inference to describe spectrum data. This conventional fitting method founded for example in Genie 2000 is compared with the nonparametric SINBAD approach regarding some key figures of merit as the peak centroid evaluation (identification) and peak surface evaluation (quantification). Unfriendly cases are studied for nuclides detection with closed gamma-rays energies and high photoelectric peak intensity differences. Tests are performed with spectra from the International Atomic Energy Agency (IAEA) for gamma spectra analysis software benchmark and with spectra acquired at the laboratory. Results show that SINBAD and Genie 2000 performances are quite similar with sometimes best results for SINBAD with the important difference that to achieve same performances the nonparametric method is user-friendly compared

Gamma Spectrometry Analysis of Different Brands of Cement used in Nigeria

International Nuclear Information System (INIS)

Olarinoye, I.O.; Baba-Kutigi, A.N.; Sharifat, I.; Kolo, M.T.

2014-01-01

The natural radionuclide content of common brands of cement consumed in Nigeria is presented in this work. Samples of 9 brands of grey ordinary Portland cement (OPC) and 5 brands of white cement were collected and analyzed for their radiological content by gamma spectrometry using a 7.6 x 7.6 NaI(TI) detector. The total average content of 226 Ra, 232 Th and 40 k for all the cement brand samples were 38.1, 27.9 and 301.1 Bq/kg respectively and are lower when compared to the world average (50, 50 and 500 Bq/Kg) in building materials. The evaluated radium equivalent activities, external and internal indices were lower than the recommended safe limit and are comparable with result from similar studies concluded in other countries. The evaluation mean gonadal dose of equivalents of two cement brand samples were found to be higher than the world average in soil while others are less than the world average in soil.

Use of Airborne Gamma-Ray Spectrometry in case of emergency. Example of HELGA exercise - collaboration between France and Germany

International Nuclear Information System (INIS)

Guillot, L.

2004-01-01

Since Chernobyl accident, airborne gamma-ray spectrometry has been recognised as a useful tool to evaluate consequences of an accident over large areas. Nine European countries have capabilities to perform such measurements. Between 1996 and 2003, a collaboration between these teams was supported by European community. In 2002, an exercise involving airborne and ground-based measurements was organised in Scotland. This exercise demonstrated the ability of European countries to provide assistance to one of them in case of emergency. Since this project has been completed, the French and German team decided to continue a collaboration. The CEA team (France) went in Germany in 2003 to participate to a survey with the German team. In September 2004, an exercise including mapping of contaminated areas and orphan sources search is planned in France. Such actions are good opportunities to exchange technical information about the acquisition systems and operating procedures. It is also essential to improve the availability of teams to obtain comparable and compatible results. The AGRS (airborne gamma ray spectrometry) systems involved in this exercise will be described and compared in this paper. The capacity of teams to work in collaboration in various situation (orphan source search, contamination mapping) will be then evaluated. In particular, a European Radiometric and Spectrometry format defined during Eccomags project will be used to create a database of raw and processed data. The aim is to produce quickly composite maps with data recorded by different teams. A choice of results will be presented and an assessment of capability of teams to work in collaboration will be done. (author)

Validation of Am-241 measurement in ion chamber type smoke detector by using gamma spectrometry system

International Nuclear Information System (INIS)

Yii Mei Wo; Khairul Nizam Razali

2005-01-01

Smoke detectors are useful devices in modern days that able to save many lives. Even though, the use of ion chamber type smoke detector (usually contain Americium-241) was exempted in Malaysia, but the trading of this device was controlled by regulation, under the Atomic Energy Licensing Act (Act 304). The activity of the Am-241 can be measured by using the Gamma Spectrometry System since it was much easier, compared to Alpha Spectrometry System. To do so, the system was first need to be calibrated using the standard reference source to find the efficiency of the germanium detector. The method used for the measurement was first validated for several relevant parameters, which include specificity, precision (repeatability), bias (accuracy), linearity, working range, detection limit, robustness and ruggedness to ensure it was fit for the purpose. The measured Am-241 activity inside the smoke detector will be reported together with a reasonable expanded uncertainty arise from the measurement. (Author)

Normal-Gamma-Bernoulli Peak Detection for Analysis of Comprehensive Two-Dimensional Gas Chromatography Mass Spectrometry Data.

Science.gov (United States)

Kim, Seongho; Jang, Hyejeong; Koo, Imhoi; Lee, Joohyoung; Zhang, Xiang

2017-01-01

Compared to other analytical platforms, comprehensive two-dimensional gas chromatography coupled with mass spectrometry (GC×GC-MS) has much increased separation power for analysis of complex samples and thus is increasingly used in metabolomics for biomarker discovery. However, accurate peak detection remains a bottleneck for wide applications of GC×GC-MS. Therefore, the normal-exponential-Bernoulli (NEB) model is generalized by gamma distribution and a new peak detection algorithm using the normal-gamma-Bernoulli (NGB) model is developed. Unlike the NEB model, the NGB model has no closed-form analytical solution, hampering its practical use in peak detection. To circumvent this difficulty, three numerical approaches, which are fast Fourier transform (FFT), the first-order and the second-order delta methods (D1 and D2), are introduced. The applications to simulated data and two real GC×GC-MS data sets show that the NGB-D1 method performs the best in terms of both computational expense and peak detection performance.

Survey of the 137Cs contamination in Belgium by in-situ gamma spectrometry, a decade after the Chernobyl accident.

Science.gov (United States)

Uyttenhove, J; Pommé, S; Van Waeyenberge, B; Hardeman, F; Buysse, J; Culot, J P

1997-10-01

The residual radiocesium concentration, nearly 10 y after the Chernobyl accident, is measured at different sites on the Belgian territory by means of in-situ gamma-spectrometry. A possible link between the rainfall at the beginning of May 1986 and the actual cesium concentration is investigated. The radiological impact of this contamination, even in the most affected regions in the Ardennes, is very small (<6 microSv y(-1)).

A rapid dissolution procedure to aid initial nuclear forensics investigations of chemically refractory compounds and particles prior to gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Reading, David G., E-mail: d.reading@noc.soton.ac.uk [GAU-Radioanalytical Laboratories, Ocean and Earth Science, University of Southampton, National Oceanography Centre, European Way, Southampton SO14 3ZH (United Kingdom); Croudace, Ian W.; Warwick, Phillip E. [GAU-Radioanalytical Laboratories, Ocean and Earth Science, University of Southampton, National Oceanography Centre, European Way, Southampton SO14 3ZH (United Kingdom); Britton, Richard [AWE plc, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom)

2015-11-05

A rapid and effective preparative procedure has been evaluated for the accurate determination of low-energy (40–200 keV) gamma-emitting radionuclides ({sup 210}Pb, {sup 234}Th, {sup 226}Ra, {sup 235}U) in uranium ores and uranium ore concentrates (UOCs) using high-resolution gamma ray spectrometry. The measurement of low-energy gamma photons is complicated in heterogeneous samples containing high-density mineral phases and in such situations activity concentrations will be underestimated. This is because attenuation corrections, calculated based on sample mean density, do not properly correct where dense grains are dispersed within a less dense matrix (analogous to a nugget effect). The current method overcomes these problems using a lithium tetraborate fusion that readily dissolves all components including high-density, self-attenuating minerals/compounds. This is the ideal method for dissolving complex, non-volatile components in soils, rocks, mineral concentrates, and other materials where density reduction is required. Lithium borate fusion avoids the need for theoretical efficiency corrections or measurement of matrix matched calibration standards. The resulting homogeneous quenched glass produced can be quickly dissolved in nitric acid producing low-density solutions that can be counted by gamma spectrometry. The effectiveness of the technique is demonstrated using uranium-bearing Certified Reference Materials and provides accurate activity concentration determinations compared to the underestimated activity concentrations derived from direct measurements of a bulk sample. The procedure offers an effective solution for initial nuclear forensic studies where complex refractory minerals or matrices exist. It is also significantly faster, safer and simpler than alternative approaches. - Highlights: • Low energy gamma photons (<200 keV) are attenuated in U-bearing compounds. • Corrections based on bulk density do not yield accurate activity

Determination of low-level Radium isotope activities in fresh waters by gamma spectrometry

International Nuclear Information System (INIS)

Molina Porras, Arnold; Condomines, Michel; Seidel, Jean Luc

2017-01-01

A new portable sampling system was developed to extract Radium isotopes from large volumes (up to 300 L) of fresh surface- and ground-waters of low Ra-activities (<5 mBq/L). Ra is quantitatively adsorbed on a small amount (6.5 g) of MnO_2-coated acrylic fibers, which are then dried and burned at 600 °C in the laboratory. The resulting Mn-oxide powder (about 2 cm"3 when compacted) is then analyzed through gamma-ray spectrometry which allows measurement of the whole Ra quartet ("2"2"6Ra, "2"2"8Ra, "2"2"4Ra and "2"2"3Ra) in a single counting of a few days. The usual relative standard combined uncertainties (1σ) are 2–3% for "2"2"6Ra, "2"2"8Ra and "2"2"4Ra; and less than 10% for "2"2"3Ra. This method was applied to the analysis of Ra in karstic waters of the Lez aquifer, and surface- and ground-waters of the upper and middle Vidourle watershed (South of France). The analyzed waters have relatively low "2"2"6Ra activities (1–4 mBq/L) in both cases, regardless of the contrasted geology (Mesozoic limestone vs crystalline Variscan basement), but clearly distinct ("2"2"8Ra/"2"2"6Ra) ratios in agreement with the differences in Th/U ratios of the two drained areas. Short-lived Ra isotopes ("2"2"4Ra and "2"2"3Ra) appear to be mainly influenced by near-surface desorption/recoil processes for most of the sampling sites. - Highlights: • New portable system for sampling fresh- and ground-waters of low Ra activities. • Simultaneous measurement of all four radium isotopes through gamma-spectrometry. • Relative uncertainties are 2% to 3% for "2"2"6Ra, "2"2"8Ra and "2"2"4Ra; and <10 % for "2"2"3Ra. • ("2"2"8Ra/"2"2"6Ra) ratios are valuable tracers of water origin in karstic aquifers.

Urban gamma spectrometry. Report 1

International Nuclear Information System (INIS)

Aage, H.K.; Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H.

2009-06-01

This report contains the present status and results for the NKS UGS-project per 1 June 2006 for NKS partners DTU, Denmark, and STUK, Finland. The Danish and Finnish CGS (Carborne Gamma Spectrometry) systems are not of similar types. The Danish CGS system(s) only make use of one NaI(Tl) detector whereas the Finnish CGS system consists of several detectors, NaI(Tl) and HPGe both and as an additional feature the Finnish detectors have position dependent different fields of view. Furthermore, the Finnish system is equipped with an air sampling system. In terms of operation, the Danish detector is located on the rooftop where as the Finnish detectors are located inside the vehicle. The Finnish and the Danish team use different methods for data processing. STUK uses a hypothesis test method to get robust real time alarms (within 10 seconds) when significant peaks from a previously defined set of nuclides are detected. An alarm for a significantly elevated total pulse rate is sent if none of the predefined nuclides is identified. All data are stored to the LINSSI database, which facilitates easy data retrieval for post processing. DEMA/DTU bases their calculations on full spectrum fitting using NASVD and the Danish software NucSpec. Source signals are found from spectrum fitting residuals or from stripping of energy windows - either by the standard 4-windows method or by a measurement based method where stripping factors for any window of interest can be derived from the measurements themselves. A thorough description of the two systems and data processing methods (including mathematics) are described in this report. For the Danish methods of data processing some comparisons have been made, but no final conclusion has been reached yet. Raw urban data has been investigated along with urban data sets to which source signals have been added and searched for. For the Finnish method calibration plots of the minimum detection limits for two different detector types have been

Urban gamma spectrometry. Report 1

Energy Technology Data Exchange (ETDEWEB)

Aage, H K [Technical Univ. of Denmark, Kgs. Lyngby (Denmark); Kuukankorpi, S; Moring, M; Smolander, P; Toivonen, H [Radiation and Nuclear Safety Authority, Helsinki (Finland)

2009-06-15

This report contains the present status and results for the NKS UGS-project per 1 June 2006 for NKS partners DTU, Denmark, and STUK, Finland. The Danish and Finnish CGS (Carborne Gamma Spectrometry) systems are not of similar types. The Danish CGS system(s) only make use of one NaI(Tl) detector whereas the Finnish CGS system consists of several detectors, NaI(Tl) and HPGe both and as an additional feature the Finnish detectors have position dependent different fields of view. Furthermore, the Finnish system is equipped with an air sampling system. In terms of operation, the Danish detector is located on the rooftop where as the Finnish detectors are located inside the vehicle. The Finnish and the Danish team use different methods for data processing. STUK uses a hypothesis test method to get robust real time alarms (within 10 seconds) when significant peaks from a previously defined set of nuclides are detected. An alarm for a significantly elevated total pulse rate is sent if none of the predefined nuclides is identified. All data are stored to the LINSSI database, which facilitates easy data retrieval for post processing. DEMA/DTU bases their calculations on full spectrum fitting using NASVD and the Danish software NucSpec. Source signals are found from spectrum fitting residuals or from stripping of energy windows - either by the standard 4-windows method or by a measurement based method where stripping factors for any window of interest can be derived from the measurements themselves. A thorough description of the two systems and data processing methods (including mathematics) are described in this report. For the Danish methods of data processing some comparisons have been made, but no final conclusion has been reached yet. Raw urban data has been investigated along with urban data sets to which source signals have been added and searched for. For the Finnish method calibration plots of the minimum detection limits for two different detector types have been

Validation of 226Ra, 228Ra and 210Pb measurements in soil and sediment samples through high resolution gamma ray spectrometry

International Nuclear Information System (INIS)

Dias, Danila Carrijo da Silva; Silva, Nivaldo Carlos da; Bonifacio, Rodrigo Leandro; Guerrero, Eder Tadeu Zenun

2013-01-01

Radionuclides found in ore extraction waste materials are a great source of concern regarding public health and environmental safety. One technique to determine the concentration of substances is high resolution gamma ray spectrometry using HPGe. Validating a measurement technique is essential to warrant high levels of quality to any scientific work. The Laboratory of Pocos de Caldas of the Brazilian Commission for Nuclear Energy partakes into a Quality Management System project, seeking Accreditation under ISO/IEC 17025 through the validation of techniques of chemical and radiometric analysis of environmental samples from water, soil and sediment. The focus of the Radon Laboratory at LAPOC is validation of Ra-226, Ra-228 and Pb-210 concentration determinations in soil and sediment through a gamma spectrometer system. The stages of this validation process included sample reception and preparation, detector calibration and sample analyses. Dried samples were sealed in metallic containers and analyzed after radioactive equilibrium between Ra-226 and daughters Pb-214 and Bi-214. Gamma spectrometry was performed using CANBERRA HPGe detector and gamma spectrum software Genie 2000. The photo peaks used for Ra-226 determination were 609 keV and 1020 keV of Bi-214 and 351 keV of Pb-214. For the Ra-228 determination a photopeak of 911 keV was used from its short half-life daughter Ac-228 (T1/2 = 6.12 h). For Pb-210, the photopeak of 46.5 keV was used, which, due to the low energy, self-absorption correction was needed. Parameters such as precision, bias/accuracy, linearity, detection limit and uncertainty were evaluated for that purpose. The results have pointed to satisfying results. (author)

Optimization of Gamma-Ray Counting and Spectrometry in Biomedical Tracer Studies; Optimisation du Comptage et de la Spectrometrie des Rayons Gamma dans des Etudes Biomedicales Faites a l'Aide de Traceurs; Optimizatsiya gamma-scheta i spektrometrii gamma-luchej v biomeditsinskikh issledovaniyakh s pomoshch'yu indikatorov; Optimizacion del Recuento y de la Espectrometry Gamma en los Estudios Biomedicos con Indicadores

Energy Technology Data Exchange (ETDEWEB)

Guinn, V. P. [General Dynamics Corporation, San Diego, CA (United States)

1965-10-15

In biomedical tracer studies, especially in man and even more so in children and pregnant women, it is important to operate at the lowest possible level of administered radioisotope that is commensurate with the required precision and accuracy of the subsequent radioassay measurements. Similarly, with administered stable elements (as specified compounds) or enriched stable isotopes (again, in compound form), followed by radioactivation analysis of resulting samples, it is important from the toxicological standpoint to minimize the amounts of administered element. The problem of optimization of counting of one, two and three gamma-emitting radioisotopes, by Nal(Tl) scintillation counting, single-channel spectrometry and multichannel spectrometry, has been considered in some detail in these laboratories, with particular attention to single-, double-, or triple-tagging tracer studies with radioisotopes frequently used in biomedical studies: {sup 51}Cr, {sup 198}Au, {sup 75}Se, {sup 197}Hg, {sup 64}Cu, {sup 76}As, {sup 82}Br, {sup 59}Fe, {sup 60}Co, {sup 42}K, and {sup 24}Na. The same considerations apply to the widely-used thermal-neutron activation analysis determinations of the corresponding elements or enriched stable isotopes, so the results of these counting optimization calculations have a double usefulness. The calculations are based on a few reasonable assumptions made on practical biomedical considerations, namely: (1) small samples ({<=} 10 ml), (2) moderate counting periods (s 20 minutes), (3) modest allowable decay periods ({<=} 3 days) and (4) use of commercially available counting equipment and shielding. On this basis, the most sensitive methods of counting each of the aforementioned radioisotopes, and a number of pairs and trios of them, have been ascertained. The counting variables included in the considerations are: (1) type of Nal(Tl) crystal, i.e., solid or well-type, (2) size of Nal(Tl) crystal, up to a 5 in x 5 in size, (3) type of measuring

Application of fussy mathematics to the data processing of surface gamma spectrometry for gold exploration

International Nuclear Information System (INIS)

Huang Zheming.

1990-01-01

This paper introduces a new method by applying fuzzy mathematics to the data processing of uranium thorium and potassium, these data were detected from surface gamma spectrometry in the field and can be used to make quantitative interpretation for delineating gold mineralization in the favourable area. This method provides a rapid means for expanding and tracing gold deposits or occurrences and for prospecting gold deposits of the same kind and also provides an effective means for engineering design in uncovering exploration. It is of high efficiency, low cost and worth popularizing. It can be also used to look for other metallic and nonmetallic ore deposits

Simple circuit for precise measurement of live dead or clock time in gamma-ray spectrometry

International Nuclear Information System (INIS)

Hammer, W.; Sterlinski, S.

1976-01-01

The basic design features and characteristics of circuit are described in the paper. The circuit coupled to a multichannel analyser (MCA) enables one of times: live(Tsub(iota)), dead (Tsub(d)) or clock(Tsub(c)) to be measured precisely. Second one is measured by a built-in timer of MCA. Having the Tsub(c)/Tsub(iota) ratio and utilizing suitable mathematical formulas one can make the corrections for both main effects (dead-time and pile-up) which yield counting losses in gamma-ray spectrometry at high and/or variable activities. Two examples of the dead-time and pile-up corrections by using the new circuit are presented in this paper. (author)

Contribution to the isotopic analysis of nitrogen using optical spectrometry; Contribution a l'analyse isotopique de l'azote par spectrometrie optique

Energy Technology Data Exchange (ETDEWEB)

Leicknam, J P [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

The possibility of analyzing a gaseous mixture of {sup 14}N{sub 2} and {sup 14}N-{sup 15}N by emission spectrometry is well known. However, for mixtures which are poor in nitrogen 15 (isotopic abundance less than 2 per cent), the methods proposed up till now do not give sufficiently accurate results rapidly. The method of isotopic analysis proposed here only requires a spectrometer of average resolving power; it is even possible, as we have done; to use a spectrograph with a slit replacing the photographic plate, and a photomultiplier; this transformation is very simple to carry out and the signals from the detector can then be received by a recorder. Under these conditions a measurement takes only from three to ten minutes, according to the accuracy required. The light sources are made up of electrode-less discharge lamps, excited by high frequency; the filling conditions are such that the lamps may be prepared in a few minutes, the impurities being sufficiently eliminated for the measurements not to be affected. The choice of the analytical band couple depends on the relative position of the isotopic bands and on the possible presence of traces of these impurities: amongst the transitions in the system C({sup 3}{pi}{sub u}) <-> B({sup 3}{pi}{sub g}), it is the 2 {yields} 0 transition which has the most favorable position for this isotopic analysis. The method is applied to samples of varying origins (ammonium salts, fertilizer and plants): the isotopic contents are determined with an accuracy of 3 per cent in the neighbourhood of the natural abundance, and of 1 per cent when the sample contains about 1.5 atoms of nitrogen-15 for 100 atoms of nitrogen-14. The accuracy is therefore quite sufficient for most of the biological research using the mass 15 as tracer. (author) [French] La possibilite d'analyser un melange gazeux des azotes {sup 14}N{sub 2} et {sup 14}N-{sup 15}N par spectrometrie d'emission est bien connue. Cependant, pour des melanges pauvres en azote

Quantification of 235U and 238U activity concentrations for undeclared nuclear materials by a digital gamma-gamma coincidence spectroscopy.

Science.gov (United States)

Zhang, Weihua; Yi, Jing; Mekarski, Pawel; Ungar, Kurt; Hauck, Barry; Kramer, Gary H

2011-06-01

The purpose of this study is to investigate the possibility of verifying depleted uranium (DU), natural uranium (NU), low enriched uranium (LEU) and high enriched uranium (HEU) by a developed digital gamma-gamma coincidence spectroscopy. The spectroscopy consists of two NaI(Tl) scintillators and XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The results demonstrate that the spectroscopy provides an effective method of (235)U and (238)U quantification based on the count rate of their gamma-gamma coincidence counting signatures. The main advantages of this approach over the conventional gamma spectrometry include the facts of low background continuum near coincident signatures of (235)U and (238)U, less interference from other radionuclides by the gamma-gamma coincidence counting, and region-of-interest (ROI) imagine analysis for uranium enrichment determination. Compared to conventional gamma spectrometry, the method offers additional advantage of requiring minimal calibrations for (235)U and (238)U quantification at different sample geometries. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Heavy element concentration determination by the x-ray fluorescence analysis using radioisotope {gamma}-ray sources; Dosage d'elements lourds par fluorescence X utilisant des radio-sources de rayons gamma

Energy Technology Data Exchange (ETDEWEB)

Enomoto, S [Commissariat a l' Energie Atomique, Dir. des Materiaux et des Combustibles Nucleaires, Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

A theoretical and experimental study has been made on the fluorescence analysis of high atomic number element, using {gamma}-ray sources for excitation and characteristic K X-rays for the measurement. The choice of the proper {gamma}-ray energy according to the conditions of the determination is considered. The author has studied the usefulness of using the backscattered {gamma}-rays as a correction mean for matrix and grain-size effects. Sources of {sup 153}Gd, {sup 57}Co, {sup 137}Cs have been used for excitation using collimated geometries. Concentration measurements of tungsten in steel, tungsten and lead in aqueous solution, PbS in SiO{sub 2}-PbS powder mixtures have been done, as well as thickness evaluation of gold layers on copper. A precision of about 0.2 per cent (abs.) is obtained for lead determination in light matrixes. A probe design is proposed for the continuous determination of lead in aqueous solutions. (author) [French] On etudie de maniere theorique et experimentale l'analyse d'elements a nombre atomique eleve par fluorescence en utilisant des sources de rayons {gamma} pour l'excitation, et des rayons-X K caracteristiques pour la mesure. On considere le choix de l'energie appropriee des rayons {gamma} suivant les conditions experimentales. L'utilite d'employer les rayons {gamma} retrodiffuses pour corriger les effets de la matrice et de la dimension des grains est etudiee. Des sources de {sup 153}Gd, de {sup 57}Co et de {sup 137}Cs a geometrie collimatee ont ete utilisees pour l'excitation. Des mesures de la concentration du tungstene dans l'acier, du tungstene et du plomb en solutions aqueuses, et du PbS dans des melanges de poudre SiO{sub 2}-PbS ont ete entreprises ainsi que l'evaluation de l'epaisseur des couches d'or sur le cuivre. On obtient une precision d'environ 0,2 pour cent (en absolu) pour la determination du plomb dans des matrices legeres. On propose un modele de sonde pour la determination en continu du plomb en solution aqueuse

Characterization of three digital signal processor systems used in gamma ray spectrometry

International Nuclear Information System (INIS)

Reguigui, N.; Morel, J.; Ben Kraiem, H.; Mahjoub, A.

2002-01-01

Various manufacturers have recently introduced digital signal processing systems that allow data acquisition in gamma spectrometry at high-input counting rates (several thousand pulses per second). In these systems, the signal digitization is performed immediately following the preamplification stage. This allows digital shaping and filtering of the signal which increases the number of possible combinations in signal shaping and as a consequence, optimizes the resolution as a function of the detector characteristics and the counting rate. Basic characteristic parameters of three digital signal processors that were recently introduced in the market have been studied and compared to those of an analog system. This study is carried out using a hyper-pure coaxial type germanium detector and 57 Co, 60 Co and 137 Cs radioactive sources. Performance parameters such as energy resolution, system throughput, and counting losses that are due to dead time and pile-up effects are presented and discussed

Execution of a cooperative test by means of 'in-situ-gamma spectrometry' using HP-germanium detectors

International Nuclear Information System (INIS)

Steger, F.; Lovranich, E.; Urbanich, E.; Streit, S.

1995-06-01

A cooperative test was carried out in Salzburg, Austria, in order to determine the activity of Cs-137 and other radio nuclides from the Tschernobyl fallout 1986 and from tests of nuclear weapons in the 1960s. 24 groups from 9 countries of Europe took part. The measurements were performed by means of gamma spectrometry using HP-germanium detectors. Most of the groups had excellent results. The groups became acquainted with each other. The personal contact makes it possible to get information quickly in case of accidents of nuclear power stations in the neighbourhood of Austria

Self-attenuation correction in the environmental sample gamma spectrometry; Correcao de auto-absorcao na espectrometria gama de amostras ambientais

Energy Technology Data Exchange (ETDEWEB)

Venturini, Luzia; Nisti, Marcelo B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

1997-10-01

Self-attenuation corrections were calculated for gamma ray spectrometry of environmental samples with densities from 0.42 g/ml up to 1.59 g/ml, measured in Marinelli beakers and polyethylene flasks. These corrections are to be used when the counting efficiency is calculated for water measured in the same geometry. The model of Debertin for Marinelli beaker, numerical integration and experimental linear attenuation coefficients were used. (author). 3 refs., 4 figs., 6 tabs.

Compton suppression gamma ray spectrometry

International Nuclear Information System (INIS)

Landsberger, S.; Iskander, F.Y.; Niset, M.; Heydorn, K.

2002-01-01

In the past decade there have been many studies to use Compton suppression methods in routine neutron activation analysis as well as in the traditional role of low level gamma ray counting of environmental samples. On a separate path there have been many new PC based software packages that have been developed to enhance photopeak fitting. Although the newer PC based algorithms have had significant improvements, they still suffer from being effectively used in weak gamma ray lines in natural samples or in neutron activated samples that have very high Compton backgrounds. We have completed a series of experiments to show the usefulness of Compton suppression. As well we have shown the pitfalls when using Compton suppression methods for high counting deadtimes as in the case of neutron activated samples. We have also investigated if counting statistics are the same both suppressed and normal modes. Results are presented in four separate experiments. (author)

Embedded gamma spectrometry: new algorithms for spectral analysis

International Nuclear Information System (INIS)

Martin-Burtart, Nicolas

2012-01-01

Airborne gamma spectrometry was first used for mining prospecting. Three main families were looked for: K-40, U-238 and Th-232. The Chernobyl accident acted as a trigger and for the last fifteen years, a lot of new systems have been developed for intervention in case of nuclear accident or environmental purposes. Depending on their uses, new algorithms were developed, mainly for medium or high energy signal extraction. These spectral regions are characteristics of natural emissions (K-40, U-238 and Th-232 decay chains) and fissions products (mainly Cs-137 and Co-60). Below 400 keV, where special nuclear materials emit, these methods can still be used but are greatly imprecise. A new algorithm called 2-windows (extended to 3), was developed. It allows an accurate extraction, taking the flight altitude into account to minimize false detection. Watching radioactive materials traffic appeared with homeland security policy a few years ago. This particular use of dedicated sensors require a new type of algorithms. Before, one algorithm was very efficient for a particular nuclide or spectral region. Now, we need algorithm able to detect an anomaly wherever it is and whatever it is: industrial, medical or SNM. This work identified two families of methods working under these circumstances. Finally, anomalies have to be identified. IAEA recommend to watch around 30 radionuclides. A brand new identification algorithm was developed, using several rays per element and avoiding identifications conflicts. (author) [fr

Cooperation on Improved Isotopic Identification and Analysis Software for Portable, Electrically Cooled High-Resolution Gamma Spectrometry Systems Final Report

Energy Technology Data Exchange (ETDEWEB)

Dreyer, Jonathan G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wang, Tzu-Fang [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vo, Duc T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Funk, Pierre F. [Inst. for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses (France); Weber, Anne-Laure [Inst. for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses (France)

2017-07-20

Under a 2006 agreement between the Department of Energy (DOE) of the United States of America and the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) of France, the National Nuclear Security Administration (NNSA) within DOE and IRSN initiated a collaboration to improve isotopic identification and analysis of nuclear material [i.e., plutonium (Pu) and uranium (U)]. The specific aim of the collaborative project was to develop new versions of two types of isotopic identification and analysis software: (1) the fixed-energy response-function analysis for multiple energies (FRAM) codes and (2) multi-group analysis (MGA) codes. The project is entitled Action Sheet 4 – Cooperation on Improved Isotopic Identification and Analysis Software for Portable, Electrically Cooled, High-Resolution Gamma Spectrometry Systems (Action Sheet 4). FRAM and MGA/U235HI are software codes used to analyze isotopic ratios of U and Pu. FRAM is an application that uses parameter sets for the analysis of U or Pu. MGA and U235HI are two separate applications that analyze Pu or U, respectively. They have traditionally been used by safeguards practitioners to analyze gamma spectra acquired with high-resolution gamma spectrometry (HRGS) systems that are cooled by liquid nitrogen. However, it was discovered that these analysis programs were not as accurate when used on spectra acquired with a newer generation of more portable, electrically cooled HRGS (ECHRGS) systems. In response to this need, DOE/NNSA and IRSN collaborated to update the FRAM and U235HI codes to improve their performance with newer ECHRGS systems. Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL) performed this work for DOE/NNSA.

Burn-up measurements of spent fuel using gamma spectrometry technique

International Nuclear Information System (INIS)

Pereda, C.; Henriquez, C.; Klein, J.; Medel, J.

2005-01-01

Burn-up results obtained for HEU (45% of 235 U) fuel assemblies of the RECH-1 Research Reactor using gamma spectrometry technique are presented. The spectra were got from an in-pool facility built in the reactor to be mainly used to measure the burnup of irradiated fuel assemblies with short cooling time, where 95 Zr is being evaluated as possible fission monitor. A program to measure all spent fuel assemblies of the RECH-1 reactor was initiated in the frame of the Regional Project RLA/4/018: 'Management of Spent Fuel from Research Reactors'. The results presented here were obtained from HEU spent fuel assemblies with cooling time greater than 100 days and 137 Cs was used as fission monitor. The efficiency of the in-pool system was determined using a slightly burnt experimental fuel assembly, which has one fuel plate (one of the outer plates) and the rest are dummy plates. An average burn-up of 2.8% of 235 U was previously measured for the experimental fuel assembly utilizing a facility installed in a hot cell and 137 Cs was used as monitor. (author)

Gamma radiation detectors for safeguards applications

International Nuclear Information System (INIS)

Carchon, R.; Moeslinger, M.; Bourva, L.; Bass, C.; Zendel, M.

2007-01-01

The IAEA uses extensively a variety of gamma radiation detectors to verify nuclear material. These detectors are part of standardized spectrometry systems: germanium detectors for High-Resolution Gamma Spectrometry (HRGS); Cadmium Zinc Telluride (CZT) detectors for Room Temperature Gamma Spectrometry (RTGS); and NaI(Tl) detectors for Low Resolution Gamma Spectrometry (LRGS). HRGS with high-purity Germanium (HpGe) detectors cooled by liquid nitrogen is widely used in nuclear safeguards to verify the isotopic composition of plutonium or uranium in non-irradiated material. Alternative cooling systems have been evaluated and electrically cooled HpGe detectors show a potential added value, especially for unattended measurements. The spectrometric performance of CZT detectors, their robustness and simplicity are key to the successful verification of irradiated materials. Further development, such as limiting the charge trapping effects in CZT to provide improved sensitivity and energy resolution are discussed. NaI(Tl) detectors have many applications-specifically in hand-held radioisotope identification devices (RID) which are used to detect the presence of radioactive material where a lower resolution is sufficient, as they benefit from a generally higher sensitivity. The Agency is also continuously involved in the review and evaluation of new and emerging technologies in the field of radiation detection such as: Peltier-cooled CdTe detectors; semiconductor detectors operating at room temperature such as HgI 2 and GaAs; and, scintillator detectors using glass fibres or LaBr 3 . A final conclusion, proposing recommendations for future action, is made

A low-energy set-up for gamma-ray spectrometry of NORM tailored to the needs of a secondary smelting facility

OpenAIRE

Lutter, Guilome; Vandael Schreurs, Indy; Croymans, Tom; Schroeyers, Wouter; Schreurs, Sonja; Hult, Mikael; Marissens, Gert; Stroh, Heiko; Tzikaa, Faidra

2017-01-01

A measurement station dedicated for quantitative radiological characterisation of naturally occurring radio-nuclides in a metallurgical company and based on gamma-ray spectrometry was developed. The station is intended for performing quality control of final non-ferrous metal products and for radiological checks of incoming materials. A low-background point-contact HPGe-detector was used and the signal was split in two branches to enable collecting simultaneously spectra with high amplificati...

Application of the similitude principle to gamma-gamma density measurements; Application du principe de similitude a la mesure gamma-gamma de densite

Energy Technology Data Exchange (ETDEWEB)

Czubek, J A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Departement d' Electronique Generale, Service d' Electronique Industrielle; Institut de Recherches Nucleaires, Dep. VI, Cracow (Poland)

1966-07-01

The work presented here deals with the problem of the application of the similitude principle to rock density measurements by the gamma-gamma method. A formula is presented which makes it possible to transform results of gamma-gamma measurements carried out on models in order to make them suitable for comparison with results obtained under actual field conditions. Both the space coordinates and the densities are transformed. This transformation makes it possible to obtain a calibration curve as a function of the density for a gamma-gamma probe using only a single model of given density. The influence has also been studied of the chemical composition on the results obtained from gamma-gamma measurements. A method has been developed for estimating the equivalent Z parameter of the medium; the possibility of completely eliminating the influence of the chemical composition of the medium on the measurement results has been studied. (author) [French] L'etude presentee ci-dessous traite le probleme de l'application du principe de similitude aux mesures de densite des roches par la methode gamma-gamma. Nous indiquons une formule qui permet de transformer les resultats des mesures gamma-gamma effectuees sur les modeles pour les comparer aux resultats obtenus dans les conditions reelles sur le terrain. On transforme les coordonnees spatiales ainsi que les densites. Cette transformation donne la possibilite d'obtenir une courbe d'etalonnage (en fonction de la densite) pour une sonde gamma-gamma en utilisant un seul modele de densite donnee. On a etudie aussi l'influence de la composition chimique sur les resultats obtenus des mesures gamma-gamma. On a etabli une methode d'estimation du parametre Z equivalent du milieu, ainsi que la possibilite d'eliminer completement l'influence de la composition chimique du milieu sur les resultats des mesures de densite. (auteur)

Thermodynamic study of sulphur hemi-oxide using mass spectrometry (1963); Etude thermodynamique de l'hemioxyde de soufre par spectrometry de masse (1963)

Energy Technology Data Exchange (ETDEWEB)

Hagemann, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-01-15

have also examined the work concerning the heat of formation of SO to discover whether the formation of SO is possible between 1000 deg K and 1500 deg K starting from sulphur and SO{sub 2}. (author) [French] L'action de l'oxygene sur le soufre, a basse pression, dons une decharge haute frequence, a ete etudiee en analysant en continu, les produits de la reaction par spectrometrie de masse. Les spectres de masse du gaz issu de la decharge correspondent a un melange SO{sub 2}, S{sub 2}O, S{sub 2} et O{sub 2}. Nous avons mesure jusqu'a 75 pour rent de SO{sub 2} dans le melange SO{sub 2} + S{sub 2}O. Nous avons conclu a l'absence des molecules S{sub 2}O{sub 2}, et SO dans le melange. Les potentiels d'ionisation des molecules, et d'apparition des ions fragments du melange issu de la decharge, ont ete etudies par spectrometrie de masse. La chaleur de formation de S{sub 2}O a ete estimee a partir des mesures des potentiels d'apparition des ions SO{sup +} provenant de SO{sub 2}, et S{sub 2}O. (- 18.5 kcal/mole - < {delta}H, (S{sub 2}O{sub g}) < - 7 kcal/mole). Nous avons ete amenes a mesurer les potentiels d'ionisation des molecules S{sub 2}, S{sub 4}, S{sub 6} et S{sub 8} dont les valeurs sont respectivement: 9,7 {+-} 0,1 eV; 10,4 {+-} 0,5 eV; 8,5 {+-} 0,3 eV et 7,3 {+-} 0,3 eV. Nous avons enfin etudie l'equilibre de formation de StO a partir de soufre et de S{sub 2}O, dans un reacteur a filaments chauds. La mesure de la variation, entre 1100 deg K et 1500 deg K. de h constante d'equilibre de la reaction: SO{sub 2} + 3/2 S{sub 2} {r_reversible} 2 S{sub 2}O a permis de determiner la variation d'enthalpie de cette reaction ({delta}H = 5310 {+-} 370 calories) La somme d'etats de la molecule S{sub 2}O, Z{sup 0}, a ete calculee a partir des donnees bibliographiques. En appliquant a l'equilibre de formation de S{sub 2}O l'equation: Log K{sub p} = {delta}Log Z{sup 0}/N - {delta}H{sup 0}{sub 0}/RT nous avons calcule l'enthalpie de ia reaction au zero absolu ({delta}H{sup 0}{sub 0

In-situ-gamma-spectrometry intercomparison exercise in Salzburg, Austria, September 26-30, 1994

International Nuclear Information System (INIS)

Steger, F.; Lettner, H.; Andrasi, A.

1996-06-01

In-situ gamma spectrometry has become a useful method to assess the nuclide concentration of artificial and natural gamma-emitters in the soil. With such measurements it is possible to calculate the activity concentration in soil and also the nuclide specific exposure rates 1 m above ground. For the quality assurance of the measurements periodically intercomparison exercises are essential. To meet this requirement exercises were organised in different European countries since 1989. The last exercise in September 1994 was organised in Salzburg / Austria. The participation of 24 measurement teams from all over Europe emphasises the importance of the intercomparison. Salzburg was selected because the Province of Salzburg / Austria was among the heaviest contaminated region outside the former USSR by the Chernobyl fallout. Two different typical sites were selected for the measurements: Site 1 was inside the urban area of Salzburg on intensively used agricultural land which had not been disturbed since the fallout. This site is representative for intensively used agricultural regions in the Province of Salzburg. Site 2 was in the mountainous region of the Tauern on elevated altitude of approx. 1700 m. This site represents the soil and contamination conditions of the Alpine region. Both sites differ significantly in terms of different soil distribution and contents of natural and artificial radionuclides. Results of the intercomparison exercise are presented. (author)

Geochemical interpretation of gamma-ray spectrometry images from the Achala granite (Cordoba, Argentina)

International Nuclear Information System (INIS)

Lopez, Luis E.

1998-01-01

Data of an old spectrometry gamma-ray survey carried out in the Sierras Pampeanas Range by the National Atomic Energy Commission (Argentina) were reprocessed to obtain a corrected digital archive. The geochemical interpretation of the 250 x 250 meters spectrometric grids from the Achala batholith area was based on the behaviour of the radioelements in a peraluminous magma. Spectrometric maps of potassium, uranium, thorium and their ratios were used. In particular, the Th grid was very useful to define the primary magmatic evolution of the granitoids. K and U correlate roughly with Th distribution. The observed positive correlation between Th and U is thought to be the result of surficial leaching of U from uraninite. Finally, U/Th ratio allows to determine both, the magmatic evolution of the rocks and the mineral phase responsible for U content. (author)

Validation of Cs-137 measurement in food samples using gamma spectrometry system

International Nuclear Information System (INIS)

Yii Mei Wo; Kamarozaman Ishak

2005-01-01

Cs-137 was found to be one of major radionuclide contaminant present in foods consumed by human. In some countries, regulations required consumption foods moving in international trade to be scanned for caesium (Cs-134 and Cs-137) to ensure it does not exceeding the maximum permissible level. This is to ensure that the intake of such foods will not accumulate radionuclide until the significant level inside the human body. Gamma Spectrometry System was used to perform the measurement of caesium isotopes, because it was one of the easiest methods to be performed. This measuring method must be validated for several parameters include specificity, precision (repeatability), bias (accuracy), linearity, range, detection limit, robustness and ruggedness in order to ensure it is fit for the purpose. This paper would summarise how these parameters were fulfilled for this analytical method using several types certified reference materials. The same validated method would be considered workable on Cs-134 as well. (Author)

Efficiency transfer using the GEANT4 code of CERN for HPGe gamma spectrometry.

Science.gov (United States)

Chagren, S; Tekaya, M Ben; Reguigui, N; Gharbi, F

2016-01-01

In this work we apply the GEANT4 code of CERN to calculate the peak efficiency in High Pure Germanium (HPGe) gamma spectrometry using three different procedures. The first is a direct calculation. The second corresponds to the usual case of efficiency transfer between two different configurations at constant emission energy assuming a reference point detection configuration and the third, a new procedure, consists on the transfer of the peak efficiency between two detection configurations emitting the gamma ray in different energies assuming a "virtual" reference point detection configuration. No pre-optimization of the detector geometrical characteristics was performed before the transfer to test the ability of the efficiency transfer to reduce the effect of the ignorance on their real magnitude on the quality of the transferred efficiency. The obtained and measured efficiencies were found in good agreement for the two investigated methods of efficiency transfer. The obtained agreement proves that Monte Carlo method and especially the GEANT4 code constitute an efficient tool to obtain accurate detection efficiency values. The second investigated efficiency transfer procedure is useful to calibrate the HPGe gamma detector for any emission energy value for a voluminous source using one point source detection efficiency emitting in a different energy as a reference efficiency. The calculations preformed in this work were applied to the measurement exercise of the EUROMET428 project. A measurement exercise where an evaluation of the full energy peak efficiencies in the energy range 60-2000 keV for a typical coaxial p-type HpGe detector and several types of source configuration: point sources located at various distances from the detector and a cylindrical box containing three matrices was performed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Assessment of coal and ash environmental impact with the use of gamma- and X-ray spectrometry

International Nuclear Information System (INIS)

Kierzek, J.; Malozewska-Bucko, B.; Bukowski, P.; Parus, J.L.; Ciurapisnki, A.; Zaras, S.; Kunach, B.; Wiland, K.

1999-01-01

Gamma-ray spectrometry (GS), energy dispersive X-ray fluorescence (EDXRF) analysis methods and wavelength dispersive X-ray fluorescence (WDXRF) were applied for the studies of some coal components, e.g., sulphur, light and heavy metal element concentrations and naturally occurring radioactive isotope contents. Hundred fifty coal samples originating mostly from eight different coal mines from Upper Silesian Coal Basin and 150 samples of ash obtained from these coal samples in laboratory by total combustion at final temperature of 820 deg C, were analyzed. Such comparative analyses can be helpful in selection of most suitable kind of coal for burning in electrical power and heat plants to minimize the environmental pollution. (author)

Possibility of applying the gamma-gamma method to the in situ determination of uranium-ore densities; Les possibilites d'application de la methode gamma-gamma a la determination en place de la densite des minerais d'uranium

Energy Technology Data Exchange (ETDEWEB)

Czubek, J; Guitton, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

The principles of the gamma-gamma method are reviewed. It is shown in particular that, under certain conditions, the method makes it possible to obtain a representative measurement of the electronic density. Chemical analyses have been carried out on samples obtained from uranium deposits. The results show that an exact correlation exists between the massive and electronic densities. It is possible to consider the possibility of measuring the density of uranium-containing rocks by the gamma-gamma method. (authors) [French] Les principes de la methode gamma-gamma sont rappeles. En particulier, il est montre que, dans certaines conditions, la methode permet une mesure representative de la densite electronique. Des analyses chimiques ont ete effectuees sur des echantillons provenant de gisements uraniferes. Les resultats indiquent qu'il existe une correlation precise entre leur densite massique et leur densite electronique. Il est possible d'envisager la mesure de la densite des roches uraniferes par la methode gamma-gamma.

Detection of high energy gamma radiations with liquid rare gases as scintillators; Detection des rayonnements Gamma de grande energie avec les gaz rares liquides comme scintillateurs

Energy Technology Data Exchange (ETDEWEB)

Ho, Phan Xuan

1965-11-25

This research thesis reports the study of a sensor based on a liquid scintillator for the detection of high energy (10 to 30 MeV) gamma radiations. The scintillator is a liquefied argon or xenon rare gas. The author first studies the process of energy transfer from the particle to the sensing medium. He addresses the different involved elements and phenomena: electromagnetic radiations (Compton Effect, photoelectric effect, pair production, and total gamma absorption), charged particles (braking radiation, collisions) and application to gamma spectrometry. He describes and discusses the scintillation mechanisms (scintillation of organic and inorganic materials), the general characteristics of scintillators (impurities, converters), and then reports the practical realisation of the sensor. Results are presented and discussed [French] Dans ce travail, nous nous proposons d'etudier une technique. Il s'agit d'un detecteur a scintillateur liquide pour la detection des rayonnements gamma energiques (10 a 30 MeV). Le scintillateur utilise est un gaz rare liquefie argon ou xenon. Nous examinerons d'abord les processus de transfert de l'energie de la particule au milieu detecteur puis les mecanismes de scintillation en general pour pouvoir exploiter au mieux les phenomenes favorables. Nous presenterons ensuite la realisation pratique du detecteur. Ses qualites (et defauts) trouveront leur place dans la fin de ce memoire. Bien qu'a l'heure actuelle, par la methode de Kyropoulos, on puisse faire pousser des gros cristaux d'iodure de sodium, l'utilisation des 'gaz rares' liquefies comme scintillateurs est, grace a la brievete de la scintillation, tres utile lorsqu'on recherche un fort taux de comptage (jusqu'a 10 impulsions par seconde) ou lorsqu'on veut resoudre certains problemes de coincidence. Les cristaux NaI(Tl) de grandes dimensions sont d'un montage facile mais leur manipulation requiert beaucoup de precautions du fait qu'ils supportent tres mal les chocs thermiques

Determination of Th and U by neutron activation for gamma spectrometry calibration in situ; Determinacion de Th y U por activacion neutronica para calibracion de espectrometria gamma in situ

Energy Technology Data Exchange (ETDEWEB)

Nava M, F.; Rios M, C.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas (Mexico); Landsberger, S., E-mail: iqnava@hotmail.com [University of Texas at Austin, Nuclear Engineering Teaching Laboratory, Pickle Research Campus, R9000 Austin, Texas 78712 (United States)

2012-10-15

Using the analysis by neutron activation to determine the profile of the thorium and uranium concentration calibration factors were obtained for their use in the gamma spectrometry in situ. Three sites were selected (San Ramon, Villa de Cos y la Zacatecana) and the analysis by activation was development in the Laboratory of Nuclear Engineering Teaching of the Texas University in Austin with the nuclear reactor Ut-TRIGA. Starting from the gamma spectra in situ, the areas of normalized photo-pick of the radioisotopes were: {sup 208}Tl and {sup 228}Ac for the thorium series and {sup 214}Pb and {sup 214}Bi for the uranium series. The averages of the factors found in units of (cpm/Bq/Kg) are of 105.63{+-}8.32 and 75.87{+-}4.61 for the thorium and uranium, respectively. (Author)

LAFARA: a new underground laboratory in the French Pyrénées for ultra low-level gamma-ray spectrometry

International Nuclear Information System (INIS)

Beek, P. van; Souhaut, M.; Lansard, B.; Bourquin, M.; Reyss, J.-L.; Ballmoos, P. von; Jean, P.

2013-01-01

We describe a new underground laboratory, namely LAFARA (for “LAboratoire de mesure des FAibles RAdioactivités”), that was recently created in the French Pyrénées. This laboratory is primarily designed to analyze environmental samples that display low radioactivity levels using gamma-ray spectrometry. Two high-purity germanium detectors were placed under 85 m of rock (ca. 215 m water equivalent) in the tunnel of Ferrières (Ariège, France). The background is thus reduced by a factor of ∼20 in comparison to above-ground laboratories. Both detectors are fully equipped so that the samples can be analyzed in an automatic mode without requiring permanent presence of a technician in the laboratory. Auto-samplers (twenty positions) and systems to fill liquid nitrogen automatically provide one month of autonomy to the spectrometers. The LAFARA facility allows us to develop new applications in the field of environmental sciences based on the use of natural radionuclides present at low levels in the environment. As an illustration, we present two of these applications: i) dating of marine sediments using the decay of 226 Ra in sedimentary barite (BaSO 4 ), ii) determination of 227 Ac ( 231 Pa) activities in marine sediment cores. - Highlights: ► We describe a new underground laboratory that allows us to conduct low-background gamma-ray spectrometry. ► The background in the underground laboratory is reduced by a factor of ∼20 in comparison to above-ground laboratories. ► The 2 gamma spectrometers are equipped so that they can run automatically (one month of autonomy).

On-line interrogation of pebble bed reactor fuel using passive gamma-ray spectrometry

Science.gov (United States)

Chen, Jianwei

The Pebble Bed Reactor (PBR) is a helium-cooled, graphite-moderated high temperature nuclear power reactor. In addition to its inherently safe design, a unique feature of this reactor is its multipass fuel cycle in which graphite fuel pebbles (of varying enrichment) are randomly loaded and continuously circulated through the core until they reach their prescribed end-of-life burnup limit (˜80,000--100,000 MWD/MTU). Unlike the situation with conventional light water reactors (LWRs), depending solely on computational methods to perform in-core fuel management will be highly inaccurate. As a result, an on-line measurement approach becomes the only accurate method to assess whether a particular pebble has reached its end-of-life burnup limit. In this work, an investigation was performed to assess the feasibility of passive gamma-ray spectrometry assay as an approach for on-line interrogation of PBR fuel for the simultaneous determination of burnup and enrichment on a pebble-by-pebble basis. Due to the unavailability of irradiated or fresh pebbles, Monte Carlo simulations were used to study the gamma-ray spectra of the PBR fuel at various levels of burnup. A pebble depletion calculation was performed using the ORIGEN code, which yielded the gamma-ray source term that was introduced into the input of an MCNP simulation. The MCNP simulation assumed the use of a high-purity coaxial germanium detector. Due to the lack of one-group high temperature reactor cross sections for ORIGEN, a heterogeneous MCNP model was developed to describe a typical PBR core. Subsequently, the code MONTEBURNS was used to couple the MCNP model and ORIGEN. This approach allowed the development of the burnup-dependent, one-group spectral-averaged PBR cross sections to be used in the ORIGEN pebble depletion calculation. Based on the above studies, a relative approach for performing the measurements was established. The approach is based on using the relative activities of Np-239/I-132 in combination

Using multi spherical spectrometry for determination of dosimetric characteristics of mixed neutron and gamma radiation fields of fission sources

International Nuclear Information System (INIS)

Fyulep, M.; Nikodemova, D.; Grabovtsova, A.; Galan, P.; Trousil, J.

1977-01-01

Possibilities of the application of multispherical spectrometry in personnel dosimetry of neutrons (n) and gamma radiation (γ) are considered. Studies were made to elucidate a possibility of using albedo dosemeters to increase the sensitivity of personnel dosemeters. Determined were the dose due to the (n,γ) reaction in a human body, absorbed dose and dose equivalent. The effect of (n,γ) dose on the reading of personnel gamma dosemeter was considered. It is shown that the above effect on the dosemeter readings for frontal irradiation by a broad neutron beam in everyday personnel dosimetry near 252 Cf sources may be neglected. Only in the case of strongly slowed-down fission spectrum the effect of the (n,γ) reaction is considerable. The application of albedo dosemeter is expedient to take into account the corrections of personnel dosemeter readings [ru

Some applications of neutron activation analysis in plant biology and agronomy; Quelques applications de l'analyse par radioactivation neutronique en biologie vegetale et en agronomie

Energy Technology Data Exchange (ETDEWEB)

Fourcy, A [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1966-06-01

Plants materials are not so commonly analysed by radioactivation than biological extracts of medical importance. With help of concrete examples, applications of neutrons activation analysis to the determination of some metals (Mn, Cu, Co, Fe, Zn, and K) in plant materials, are proposed. Samples are activated in a swimming-pool reactor at the thermal flux of 5.10{sup 12} n.cm{sup -2}s{sup -1} for a time varying between few minutes and several days according to the element being analysed. The induced radioactivity is measured by spectrometry, with radiochemical separation ( Cu, Co, Fe, Zn and K) or without separation in best cases (Mn,Cu, K). Described dosages are related to: manganese in a graminaceous plant, copper in vine treatments, cobalt, iron and zinc in animal feeding, potassium in a radiological experiment. (author) [French] Les produits vegetaux sont beaucoup moins souvent soumis a l'analyse par activation que les extraits biologiques d'interet medical. En s'appuyant sur des cas concrets, nous proposons des applications de l'analyse par activation neutronique au dosage de differents metaux (Mn, Cu, Co, Fe, Zn, et K) dans la matiere vegetale. Les echantillons sont actives en pile piscine au flux thermique de 5.10{sup 12} n.cm{sup -2} s{sup -1} pendant des temps variant de quelques minutes a plusieurs jours selon les elements a analyser. le comptage de la radioactivite induite est effectue par spectrometrie gamma apres separation radiochimique (Cu, Co, Fe, Zn, et K) ou sans separation dans les cas favorables (Mn, Cu, K). Les dosages decrits concernent: le manganese dans une graminee, le cuivre en viticulture, le cobalt, le fer, et le zinc dans un aliment du betail, le potassium dans une experience de radioecologie. (auteur)

Localizing by autoradiography at -195 deg radioactive areas in rats exposed to a high flux of thermal neutrons, importance of phosphorus 32 in consecutive internal irradiation; Localisation par autoradiographie a -195 deg des zones radioactives chez le rat expose a un haut flux de neutrons thermiques, importance du phosphore 32 dans l'irradiation interne consecutive

Energy Technology Data Exchange (ETDEWEB)

Chanteur, J; Pellerin, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1961-07-01

Rats weighing 25 g were exposed for 5 mn to a flux of 6.10{sup 12} thermal neutrons/cm{sup 2}/s. Anatomical autoradiography at -195 deg. C has enabled the radioactive organs to be easily localised, to follow in course of time the decrease of radioactivity, and from it to deduce the probable nature of the numerous emitters in question. In particular, the phosphorus 32 has thus appeared to be one of those responsible for internal irradiation, general, on the one hand, by activating cellular phosphorus, local, on the other, by activating bony phosphates. Owing to this, an accidental irradiation by neutrons might have consequences that are both somatic (elective irradiation of the bone marrow) and genetic (activation of nucleic acids). The gamma spectrometry has confirmed the nature of certain other emitters. (author) [French] Des rats de 25 g ont ete exposes pendant 5 mn a un flux de 6.10{sup 12} neutrons thermiques/cm{sup 2}/s. L'autoradiographie anatomique a -195 deg. C a permis de localiser facilement les organes radioactifs, de suivre dans le temps la decroissance de la radioactivite, et d'en deduire la nature probable des nombreux emetteurs en cause. En particulier, le phosphore 32 est ainsi apparu comme l'un des responsables de l'irradiation interne, d'une part generale par activation du phosphore cellulaire, d'autre part locale par activation des phosphates osseux. Une irradiations accidentelle par neutrons aurait, de ce fait, des consequences a la fois somatiques (irradiation elective de la moelle osseuse) et genetiques (activation des acides nucleiques). La spectrometrie gamma a confirme la nature de certains autres emetteurs. (auteur)

Comparison of laser fluorimetry, high resolution gamma-ray spectrometry and neutron activation analysis techniques for determination of uranium content in soil samples

International Nuclear Information System (INIS)

Ghods, A.; Asgharizadeh, F.; Salimi, B.; Abbasi, A.

2004-01-01

Much more concern is given nowadays for exposure of the world population to natural radiation especially to uranium since 57% of that exposure is due to radon-222, which is a member of uranium decay series. Most of the methods used for uranium determination is low concentration require either tedious separation and preconcentration or the accessibility to special instrumentation for detection of uranium at this low level. this study compares three techniques and methods for uranium analysis among different soil sample with variable uranium contents. Two of these techniques, neutron activation analysis and high resolution gamma-ray spectrometry , are non-destructive while the other, laser fluorimetry is done via chemical extraction of uranium. Analysis of standard materials is done also to control the quality and accuracy of the work. In spite of having quite variable ranges of detection limit, results obtained by high resolution gamma-ray spectrometry based on the assumption of having secular equilibrium between uranium and its daughters, which causes deviation whenever this condition was missed. For samples with reasonable uranium content, neutron activation analysis would be a rapid and reliable technique, while for low uranium content laser fluorimetry would be the most appropriate and accurate technique

Emergency response exercise of laboratories equipped with gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Mala, Helena; Rulik, Petr; Jezkova, Tereza; Beckova, Vera [National Radiation Protection Institute (SURO), 140 00 Praha 28 (Czech Republic)

2014-07-01

At present 7 laboratories equipped with semiconductor gamma spectrometry (HPGe detectors) are included in the Radiation Monitoring Network (RMN) in the Czech Republic. These laboratories have 31 spectrometric chains and approximately 20 'experts' and 70 'users' who would guarantee measurements during a radiological emergency (RE). The stress exercise (a load test) was carried out in 4 of them. The aim was to test their measuring capacity in existing technical facilities and staff in the event of a RE and identify problems (bottlenecks) in the whole process from receipt of samples to entering the results into the central database of RMN. Duration of the exercise was 8 to 14 hours. Due to lack of staff, work in one 12-hour shift during a RE is presumed, which the laboratories should be able to provide for 14 days. Exercise samples covered a wide range of commodities that would probably come to the laboratories during RE (aerosol filters, adsorbed gaseous forms of iodine, fallout, surface and drinking waters, food chain components and soils). Some of the samples were previously spiked with {sup 85}Sr, {sup 88}Y and {sup 40}K (these nuclides represented actual nuclides that would occur in RE); soil samples contained higher values of {sup 137}Cs activity originating from the Chernobyl accident. Almost 40 employees took part in the exercise and measurements were carried out at 18 spectrometric chains. An automatic gamma counter which allows automatic operation of two HPGe detectors including the analysis of the spectra with a storage for up to 180 sample containers was operating in one of the laboratories involved in the exercise. The procedures in individual laboratories varied slightly depending on the staff and laboratory space available. During the exercise about 700 samples were evaluated; in addition, gamma-automat measured other 80 samples in the 'night shift'. 700 samples, this means 40 samples per a spectrometric chain or, from

Low-resolution gamma-ray spectrometry for an information barrier based on a multi-criteria template-matching approach

Energy Technology Data Exchange (ETDEWEB)

Göttsche, Malte; Schirm, Janet; Glaser, Alexander

2016-12-21

Gamma-ray spectrometry has been successfully employed to identify unique items containing special nuclear materials. Template information barriers have been developed in the past to confirm items as warheads by comparing their gamma signature to the signature of true warheads. Their development has, however, not been fully transparent, and they may not be sensitive to some relevant evasion scenarios. We develop a fully open template information barrier concept, based on low-resolution measurements, which, by design, reduces the extent of revealed sensitive information. The concept is based on three signatures of an item to be compared to a recorded template. The similarity of the spectrum is assessed by a modification of the Kolmogorov–Smirnov test to confirm the isotopic composition. The total gamma count rate must agree with the template as a measure of the projected surface of the object. In order to detect the diversion of fissile material from the interior of an item, a polyethylene mask is placed in front of the detector. Neutrons from spontaneous and induced fission events in the item produce 2.223 MeV gamma rays from neutron capture by hydrogen-1 in the mask. This peak is detected and its intensity scales with the item's fissile mass. The analysis based on MCNP Monte Carlo simulations of various plutonium configurations suggests that this concept can distinguish a valid item from a variety of invalid ones. The concept intentionally avoids any assumptions about specific spectral features, such as looking for specific gamma peaks of specific isotopes, thereby facilitating a fully unclassified discussion. By making all aspects public and allowing interested participants to contribute to the development and benchmarking, we enable a more open and inclusive discourse on this matter.

Comparative studies for determining U-235/U-238 relation in solutions of natural and depleted uranium using gamma spectrometry and neutron activation analysis

International Nuclear Information System (INIS)

Cassorla F, V.; Valle M, L.; Pena V, L.

1988-01-01

Two experimental methods were developed for determining U-235/U-238 ratio in uranium solutions. The isotopic was measured by high resolution ratio gamma-ray spectrometry (G.S.) and neutron activation analysis (N.A.A.). The precision obtained was similar for both methods, but better sensitivity was obtained by N.A.A. The accuracy in both cases was stablished by comparison with samples previously analyzed by mass spectrometry, the results were satisfactory for both techniques. Studies involving the influence of the nitric acid concentration on the isotopic ratio measurement, also were done. In addition, computer programs for faster data reduction were developped, in the case of N.A.A. (author)

Automated gamma spectrometry and data analysis on radiometric neutron dosimeters

International Nuclear Information System (INIS)

Matsumoto, W.Y.

1983-01-01

An automated gamma-ray spectrometry system was designed and implemented by the Westinghouse Hanford Company at the Hanford Engineering Development Laboratory (HEDL) to analyze radiometric neutron dosimeters. Unattended, automatic, 24 hour/day, 7 day/week operation with online data analysis and mainframe-computer compatible magnetic tape output are system features. The system was used to analyze most of the 4000-plus radiometric monitors (RM's) from extensive reactor characterization tests during startup and initial operation of th Fast Flux Test Facility (FFTF). The FFTF, operated by HEDL for the Department of Energy, incorporates a 400 MW(th) sodium-cooled fast reactor. Aumomated system hardware consists of a high purity germanium detector, a computerized multichannel analyzer data acquisition system (Nuclear Data, Inc. Model 6620) with two dual 2.5 Mbyte magnetic disk drives plus two 10.5 inch reel magnetic tape units for mass storage of programs/data and an automated Sample Changer-Positioner (ASC-P) run with a programmable controller. The ASC-P has a 200 sample capacity and 12 calibrated counting (analysis) positions ranging from 6 inches (15 cm) to more than 20 feet (6.1 m) from the detector. The system software was programmed in Fortran at HEDL, except for the Nuclear Data, Inc. Peak Search and Analysis Program and Disk Operating System (MIDAS+)

Gamma ray spectrometry results from core samples collected for RESUME 95

International Nuclear Information System (INIS)

Sanderson, D.C.W.; Allyson, J.D.; Toivonen, H.; Honkamaa, T.

1997-01-01

Field sampling of an airfield at Vesivehmaa, near Vaeaeksy, Finland (Area I) was carried out between 26-29 May 1995, to establish the radionuclide deposition and inventory of Chernobyl derived 137 Cs, and natural radionuclides. The objective was to establish a common calibration site for in-situ and airborne gamma spectrometers, for Exercise RESUME 95 conducted in August 1995. The report presents the sampling details, handling and treatment. The analyses are discussed with particular emphasis given to 137 Ca, 134 Cs, 40 K, 214 Bi and 208 radionuclides, and the quantification of their respective deposition and inventories. The results have been used to estimate the effective concentrations of nuclides at the calibration site for in-situ and airborne gamma spectrometry, and the depth distribution. For 137 Cs the weighted mean activity per unit area takes on values of 50.7±5.2 kBq m -2 at 1 m ground clearance, 51.1±6.9 kBq m -2 at 50 m height and 47.9±8.5 kBq m -2 at 100 m. The similarity of these values confirms the suitability of the Vesivehmaa site for comparison of in-situ and airborne results despite variations of a factor of two between results from individual cores. The mean α/ρ value for 137 Cs in Area I is 0.77±0.10 cm 2 g -1 (relaxation mass per unit area, β 1.31±0.15 gcm -2 ). Additional soil sampling across parts of Area II (a 6x3 km area selected for mapping Chernobyl deposition) was carried out. The mean level of 137 Cs activity from these samples was 92.4±63 kBq m -2 , a sample taken near Laihansuo showing the largest value obtained at 172 kBq m -2 . (EG)

Batteryless {gamma}-Ray Dosimeter; Dosimetre de rayons {gamma}, sans batteries; {gamma}-dozimetr bez batarei; Dosimetro a rayos {gamma} sin bateria

Energy Technology Data Exchange (ETDEWEB)

Gross, Bernhard [National Institute of Technology, Rio de Janeiro (Brazil)

1960-06-15

The Compton current produced by X-rays and {gamma}-rays in the 0.3 to 3 MeV range is proportional to the radiant energy flux. Therefore the intensity of the current can be used as a measure of radiation dose. The present paper describes a radiation receiver and electrical measuring system suitable for Compton current measurements and results obtained with this device under irradiation from a 2000 curie Co{sup 60} source. (author) [French] Le courant de Compton produit par des rayons X et {gamma} dans le domaine d'energies compris entre 0,3 et 3 MeV est proportionnel au flux d'energie rayonnante. C'est pourquoi l'intensite du courant peut servir de mesure de la dose de rayonnements. Le memoire decrit un ensemble, appareil recepteur de rayonnements et appareil de mesure electrique, permettant de mesurer le courant de Compton et il expose les resultats obtenus, au moyen de ce dispositif, sous irradiation par une source de Co{sup 60} de 2000 curies. (author) [Spanish] La corriente de Compton producida por rayos X y rayos {gamma} de energia comprendida entre 0,3 y 3 MeV es proporcional al flujo de energia radiante. Por consiguiente, la intensidad de la corriente puede servir para medir la dosis de radiacion. En este trabajo se describen un receptor de radiaciones y un sistema de medicion electrica apropiados para determinar la intensidad de la corriente de Compton, asi como los resultados obtenidos mediante este dis- positivo cuando se irradia con una fuente de Co{sup 60} de 2000 curies. (author) [Russian] Komptonovskij potok, obrazuemyj rentgenovskim i luchami i {gamma}-luchami v predelakh ot 0,3 do 3 mehv, proportsionale n potoku luchistoj ehnergii. Poehtomu intensivnost' potoka mozhet byt' ispol'zovana dlya izmereniya dozy radiatsii. V nastoyashchem dokumente opisyvayutsya radiatsionny j priemnik i ehlektricheskaya izmeritel'naya sistema, prigodnye dlya izmerenij s pomoshch'yu komptonovskog o potoka, i rezul'taty, poluchennye s pomoshch'yu ehtogo ustrojstva v khode

Radon fixation for determination of {sup 224}Ra, {sup 226}Ra and {sup 228}Ra via gamma-ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Herranz, M. [Departamento Ingenieria Nuclear y Mecanica de Fluidos, E. S. Ingenieros de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n, 48013 Bilbao (Spain)]. E-mail: inphesom@bi.ehu.es; Idoeta, R. [Departamento Ingenieria Nuclear y Mecanica de Fluidos, E. S. Ingenieros de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n, 48013 Bilbao (Spain); Abelairas, A. [Departamento Ingenieria Nuclear y Mecanica de Fluidos, E. S. Ingenieros de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n, 48013 Bilbao (Spain); Legarda, F. [Departamento Ingenieria Nuclear y Mecanica de Fluidos, E. S. Ingenieros de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n, 48013 Bilbao (Spain)

2006-04-15

The aim of this work is the improvement of the procedure for the determination of radium isotopes activities in water, which is done through radiochemical separation and subsequent gamma-ray spectrometry. In addition, radon gas retention is studied using different activated carbon materials. The results of the IAEA Proficiency test: 'Determination of radium and uranium radionuclides in water' of December 2002 [IAEA, 2003. Analytical quality control services: determination of radium and uranium radionuclides in water. Preliminary Report, Seibersdorf] are considered for this work.

Multivariate statistical approximation of the in situ gamma-ray spectrometry of the State of Zacatecas, Mexico

International Nuclear Information System (INIS)

Lopez I, J. F.; Rios M, C.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J.L.

2017-09-01

The environmental radioactivity evaluation is a key point in the assessment of the environmental quality. Through this, it can be found possible radioactive contamination, locate possible Uranium and Thorium deposits and evaluate the primordial isotopes concentration due to human activities. A radioactive map of the Zacatecas State, Mexico is under construction based on in situ gamma-ray spectrometry. The present work reports the results of the multivariate statistical approximation of the measured activity data. Based on Pearson correlation, the 228 Ac and 208 Tl activities are statistically significant, while the 214 Bi and 214 Pb activities are not statistically significant. These can be due to the existence or not of secular equilibrium in the Thorium and Uranium series. (Author)

Identification of early Llandovery (Silurian) anoxic palaeo-depressions at the western margin of the Murzuq Basin (southwest Libya), based on gamma-ray spectrometry in surface exposures

Czech Academy of Sciences Publication Activity Database

Fello, N.; Lüning, S.; Štorch, Petr; Redfern, J.

2006-01-01

Roč. 11, č. 3 (2006), s. 101-118 ISSN 1025-6059 R&D Projects: GA ČR GA205/99/1322 Institutional research plan: CEZ:AV0Z30130516 Keywords : postglacial anoxy * early Llandovery * Murzuq Basin * palaeo-depressions * gamma-spectrometry Subject RIV: DB - Geology ; Mineralogy

Preliminary Determination of Natural Radioactivity Levels of the State of Qatar using High-Resolution Gamma-ray Spectrometry

International Nuclear Information System (INIS)

Al-Sulaiti, H.A.; Regan, P.H.; Bradley, D.A.; Matthews, M.; Santawamaitre, T.; Malain, D.

2009-01-01

The State of Qatar is a peninsula with a total area of 11,437 km 2 which lies over a geological formation comprising a sequence of limestone, chalk, clay and gypsum. Establishing a baseline for the radioactivity concentration in Qatar's soil is the main purpose behind the present study. The project is focused on obtaining measurements of representative soil samples from various areas in Qatar to establish concentrations of the 235 U, 238 U and 232 Th natural decay chains and also the long-lived naturally occurring radionuclide 40 K. The 235 U, 238 U, 232 Th and 40 K concentrations have been measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector situated in a low-background environment with a copper inner-plated passive lead shield. A wide range of different gamma-ray energy transitions lines arising from the multiple decay products from the 235 U, 238 U and 232 Th decay chains have been analyzed separately to obtain more statistically significant overall results

Coincidence summing corrections for positron emitters in germanium gamma spectrometry

International Nuclear Information System (INIS)

Richardson, A.E.; Sallee, W.W.; New Mexico State Univ., Las Cruces

1990-01-01

For positron emitters, 511 keV annihilation quanta are in coincidence with other gamma rays in the decay scheme. If the positrons are not localized at the point of decay, annihilation quanta will be produced at a site some distance from the point of emission. The magnitude of the summing coincidence effect will depend upon the position of annihilation. A method for determining the magnitude of the summing effect for a single gamma of energy E in coincidence with the annihilation gammas from non-localized positrons has been developed which makes use of the counting data for the full energy peaks for both the gamma ray (E) and the 511 keV annihilation gammas. With this data and efficiency calibration data one can determine the average total efficiency for the annihilation positions from which 511 keV gammas originate, and thereby obtain the summing correction factor, SCF, for gamma ray (E). Application of the method to a 22 Na NIST standard gave excellent agreement of observed emission rates for the 1275 keV gamma with the NIST value for wide ranging degrees of positron localization having summing correction factors ranging from 1.021 to 1.505. The method was also applied successfully to 58 Co in neutron-irradiated nickel foils. The method shows promise as a check on the accuracy of the efficiency calibration for a particular detector geometry at the 511 keV energy and energies for other gammas associated with positron emission. (orig.)

Gamma irradiation-induced modifications of resins found in nuclear waste embedding processes; Modifications induites par irradiation gamma dans les differentes resines rencontrees dans le traitement des dechets nucleaires

Energy Technology Data Exchange (ETDEWEB)

Allali, H [Faculte des Science et Techniques, Settat (Morocco); Debre, O; Lambert, M; Nsouli, B; Thomas, J P [Inst. de Physique Nucleaire, Lyon-1 Univ., 69 - Villeurbanne (France); Collaboration: IPN-Lyon, Laboratoire d` Etude des Materiaux Plastiques et des Biomateriaux, URA 507, UCBL, Agence Nationale pour la Gestion des Dechets Radiactifs

1999-12-31

The various resins involved in nuclear waste disposal are subject to gamma irradiation-induced modifications. From Time-of-Flight Mass Spectrometry of Secondary ions emitted under High Energy Projectiles bombardment (HSF-SIMS) of such materials the following results are obtained: the embedding epoxy resin DGEBA-DDM does not exhibit significant bulk changes in chemical structure, whatever the dose rate and irradiation medium (air or water), at least up to 2 MGy. However, oxidation processes are well observed at the very surface. Under the same conditions Ion exchange resins to be embedded are subjected to scissions of their functional sites, leading to fixed ion release. Dehydration under irradiation is observed pointing out the crucial role of water in ion transport outside of the material. (authors)

Determination of activity by gamma spectrometry of radionuclides present in drums of residues generated in nuclear centrals; Determinacion de actividad por espectrometria gamma de radionucleidos presentes en tambores de residuos generados en centrales nucleares

Energy Technology Data Exchange (ETDEWEB)

Aguiar, J.C.; Fernandez, J. [Autoridad Regulatoria Nuclear, Av. Del Libertador 8250, Ciudad Autonoma de Buenos Aires (Argentina)]. e-mail: jaguiar@cae.arn.gov.ar

2006-07-01

The generation of radioactive residuals in nuclear centrals as CNA I (Atucha I Nuclear Central) and CNE (Embalse Nuclear Central) makes that the measurement of those radionuclides has been a previous stage to the waste management. A method used in those nuclear centrals it is the gamma spectrometry with HPGe detectors, previous to the immobilization of the residual in a cemented matrix, with this the contact with the external agents and its possible dispersion to the atmosphere in the short term is avoided. The ARN (Nuclear Regulatory Authority) of Argentina it carries out periodically intercomparisons and evaluations of the measurement and procedures systems used in the nuclear power stations for the correct measurement and determination of activity of radioactive residuals by gamma spectrometry. In this work an independent method of measurement is exposed to the nuclear power stations. To determine the activity of the residuals by gamma spectrometry deposited in drums, it is required of the precise knowledge of the efficiency curve for such geometry and matrix. Due to the RNA doesn't have a pattern of these characteristics, a mathematical model has been used to obtain this efficiency curve. For it, it is necessary to determine previously: 1) the geometric efficiency or solid angle sustained by the source-detector system (drum-detector) applying a mathematical model described in this work. 2) To estimate the auto-attenuation factor that present the photons in the cemented matrix, these calculations are carried out with a simple equation and its are verified with the Micro Shield 6.10 program. The container commonly used by these nuclear power stations its are drums for 220 liters constructed with SAE 1010 steel and with a thickness of 0.127 cm, with an approximate weight 7.73 Kg., internal diameter of 57.1 cm, and height: 87 cm. The results obtained until the moment register a discrepancy from 5 to 10% with relationship to the measurements carried out by the

Study on the natural radioactivity from the region of Presidente Figueiredo (AM), Brazil, using gamma spectrometry

International Nuclear Information System (INIS)

Da Silva, Jose Ribamar Silveira

1999-01-01

A gamma spectrometry profile was carried out along BR174 highway, that crosses some lithostratigraphic units of the North portion of the Sedimentary Basin of Amazon. Measurements in situ were realized in 116 points, 1 km apart, using a GAD-6 gamma-spectrometer and samples of rocks and soils were collected in geologically representative points, for gamma measurements using a shielded detector of NaI(Tl) available in the Nuclear Geophysics Laboratory of IAG/USP. The criterion used for evaluating the reliability degree of the concentration values of eU (ppm), eTh (ppm) and %K was to establish mathematically detection limits, for all measurement points. Every these points had been located using GPS with accuracy of 50 m to become possible a future detailed study. The purpose of matching portable gamma spectrometer and laboratory determinations was to compare the 2 techniques, using the criterion of detectability limits, and to verify the influence of 222 Rn atmospheric radioactive gas in field measurements. In the case of portable detector, it allows fast measurements and the sensor 'sees' a big volume of material (rock, soil...), that makes it more representative. In some situations where atmospheric phenomena of thermal inversion occurs, measurement can be affected by the 222 Rn cosmic background. Presence of radon daughter elements, associated with aerosols, in this tropical environment (high values of temperature and humidity), where the speed of the wind that could exhaust this gas is practically zero. It is observed that the values of concentration in the some points, got with these 2 techniques, have the same trend, and the stretches where peaks of concentration of K also occur and U and Th are associated with the presence of granite out corps, great boulders, and clay soils from weathering of these rocks. (author)

Validation of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb measurements in soil and sediment samples through high resolution gamma ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Dias, Danila Carrijo da Silva; Silva, Nivaldo Carlos da; Bonifacio, Rodrigo Leandro; Guerrero, Eder Tadeu Zenun [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas

2013-07-01

Radionuclides found in ore extraction waste materials are a great source of concern regarding public health and environmental safety. One technique to determine the concentration of substances is high resolution gamma ray spectrometry using HPGe. Validating a measurement technique is essential to warrant high levels of quality to any scientific work. The Laboratory of Pocos de Caldas of the Brazilian Commission for Nuclear Energy partakes into a Quality Management System project, seeking Accreditation under ISO/IEC 17025 through the validation of techniques of chemical and radiometric analysis of environmental samples from water, soil and sediment. The focus of the Radon Laboratory at LAPOC is validation of Ra-226, Ra-228 and Pb-210 concentration determinations in soil and sediment through a gamma spectrometer system. The stages of this validation process included sample reception and preparation, detector calibration and sample analyses. Dried samples were sealed in metallic containers and analyzed after radioactive equilibrium between Ra-226 and daughters Pb-214 and Bi-214. Gamma spectrometry was performed using CANBERRA HPGe detector and gamma spectrum software Genie 2000. The photo peaks used for Ra-226 determination were 609 keV and 1020 keV of Bi-214 and 351 keV of Pb-214. For the Ra-228 determination a photopeak of 911 keV was used from its short half-life daughter Ac-228 (T1/2 = 6.12 h). For Pb-210, the photopeak of 46.5 keV was used, which, due to the low energy, self-absorption correction was needed. Parameters such as precision, bias/accuracy, linearity, detection limit and uncertainty were evaluated for that purpose. The results have pointed to satisfying results. (author)

Natural activity in Hudson River estuary samples and their influence on the detection limits for gamma emitting radionuclides using NaI gamma spectrometry

International Nuclear Information System (INIS)

Wrenn, M.E.; Jinks, S.M.; Hairr, L.M.; Paschoa, A.S.; Lentsch, J.W.

1972-01-01

Sources of natural radioactivity in Hudson River Estuary are described. The technique of analysis for gamma spectrometry of environmental samples is presented and its pros and cons discussed. The distribution of natural radioactivity in water, biota and sediment was reported as well as the role played by the vertical distribution of cesium-137 in sediments as an indicator of the rate of sedimentation. The effect of the presence of natural radionuclides on the detection limits of man-made nuclides in the Hudson River environment is thoroughly examined. The results obtained with a 4-in. sodium iodide well crystal housed in a low background mercury shielding compare favorably with a more sophisticated Ge(Li) system which uses anticoincidence, as far as the analysis of environmental samples is concerned. (U.S.)

Application of gamma spectrometry technique in combination with weighing for material balance taking in the production of highly enriched U-A1 fuel

International Nuclear Information System (INIS)

Serin, P.A.

1975-07-01

The purpose of this project is to obtain the data on material balance for a batch of highly enriched U-Al alloys (used in the NRX and NRU reactors) during production of fuel, using gamma spectrometry (mainly the 186 KeV photopeak) and weighing, and to determine operational data of the Agency's single channel stabilized spectrometer (SAM-1) for measurement of the product typical for the production of highly enriched U-Al fuel (U-Al billets, fuel elements, scrap). The data collected indicates that gamma spectrometry using the single channel stabilized spectrometer is a valid non-destructive method of determining quantitatively U-235 content of U-Al alloy in the form of cast billets or extruded fuel elements providing that adequate standards are available. An accuracy of better than + 1% relative can be obtained using a simple jig to provide reproducible counting geometry. Count rates should be kept well below the saturation level of the detector and counter, preferably by a lead collimator in front of the detector. This non-destructive method is not easily applicable to scrap because of the inability to maintain constant geometry and to prepare standards closely similar in size and shape to the samples

Optimization of a neural network model for signal-to-background prediction in gamma-ray spectrometry

International Nuclear Information System (INIS)

Dragovic, S.; Onjia, A. . E-mail address of corresponding author: sdragovic@inep.co.yu; Dragovic, S.)

2005-01-01

The artificial neural network (ANN) model was optimized for the prediction of signal-to-background (SBR) ratio as a function of the measurement time in gamma-ray spectrometry. The network parameters: learning rate (α), momentum (μ), number of epochs (E) and number of nodes in hidden layer (N) were optimized simultaneously employing variable-size simplex method. The most accurate model with the root mean square (RMS) error of 0.073 was obtained using ANN with online backpropagation randomized (OBPR) algorithm with α = 0.27, μ 0.36, E = 14800 and N = 9. Most of the predicted and experimental SBR values for the eight radionuclides ( 226 Ra, 214 Bi, 235 U, 40 K, 232 Th, 134 Cs, 137 Cs and 7 Be), studied in this work, reasonably agreed to within 15 %, which was satisfactory accuracy. (author)

Measurement of radon concentration in water by means of {alpha}, {gamma} spectrometry. Radon concentration in ground and spring water in Hiroshima Prefecture

Energy Technology Data Exchange (ETDEWEB)

Shizuma, Kiyoshi [Hiroshima Univ. (Japan)

1997-02-01

Radon ({sup 222}Rn, T{sub 1/2}=3.8235{+-}0.0003d) is {alpha}-ray releasing nuclide, so that it can not be detected by {gamma}-ray measurement. But, the daughter nuclides {sup 214}Pb (T{sub 1/2}=26.8 min) and {sup 214}Bi (T{sub 1/2}=19.9 min) release {gamma}-ray, accordingly they are measured by Ge detector. Their radioactive equilibrium is kept in the closed vessel, because their half-lives are shorter than that of radon. We developed a measurement method of radon concentration by means of {gamma}-spectrometry. We applied this method to catch radon in the atmosphere by active carbon. The same principle can be applied to radon in water. Radon concentrations in the ground water were measured in 22 points in the Higashi-Hiroshima city and 82 points in the Hiroshima prefecture. The efficiencies of {gamma}-ray were determined. The radon concentration showed between 11 and 459 Bq/l and the average was 123 Bq/l. The high concentration of radon was distributed in the spring of granitic layer and higher concentration of radon were observed in the ground water of fault. (S.Y.)

Geiger counters of gamma rays with a bismuth cathode; Compteurs de geiger a rayons gamma a cathode de bismuth

Energy Technology Data Exchange (ETDEWEB)

Meunier, R; Legrand, J P [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1953-07-01

Geiger Muller counters present a lake of efficiency of some per cent, for the {gamma} radiations. In the region 0,3 - 1 MeV, a substantial growth of their output can be obtained by a special construction of their cathode. In accordance with previous works, we constructed some counter of formed cathode by a pleated copper wire fencing covered of Bi by electrolysis. The successive modifications brought to a cylindrical conventional cathode in sheet metal of copper, that succeeds to this type of cathode, drive to an improvement of the output. (M.B.) [French] Les compteurs de Geiger Muller presentent une efficacite assez faible de l'ordre de quelques pour cent, pour les rayonnements {gamma}. Dans la region 0,3 - 1 MeV, un accroissement substantiel de leur rendement peut etre obtenu par une construction speciale de leur cathode. Conformement a des travaux anterieurs, nous avons construit des compteurs a cathode formee par un grillage de cuivre plisse recouvert de Bi par electrolyse. Les modifications successives apportees a une cathode conventionnelle cylindrique en tole de cuivre, qui aboutissent a ce type de cathode, conduisent a une amelioration du rendement. (M.B.)

Software for nuclear spectrometry

International Nuclear Information System (INIS)

1998-10-01

The Advisory Group Meeting (AGM) on Software for Nuclear Spectrometry was dedicated to review the present status of software for nuclear spectrometry and to advise on future activities in this field. Because similar AGM and consultant's meetings had been held in the past; together with an attempt to get more streamlined, this AGM was devoted to the specific field of software for gamma ray spectrometry. Nevertheless, many of the issues discussed and the recommendations made are of general concern for any software on nuclear spectrometry. The report is organized by sections. The 'Summary' gives conclusions and recommendations adopted at the AGM. These conclusions and recommendations resulted from the discussions held during and after presentations of the scientific and technical papers. These papers are reported here in their integral form in the following Sections

Application of gamma-spectrometry to post irradiation examination

International Nuclear Information System (INIS)

Kim, S.K.; Huh, Y.H.; Park, K.J.

1982-01-01

A areat variety of nuclear gamma rays emitted from fission and activation products of spent nuclear fuel contains much information that can be elicited without affecting the integrity of the fuel elements. In the present work, a versatile code CAERI was developed which locates peaks and calculates their areas for X-rays as well as gamma rays using elegant features of some widely used programs for gamma ray peak fitting. CAERI coded in FORTRAN used infinite series approximation more accurate than other workers' various, simple, piecewise series approximations for evaluation of the Voigt function which represents the X-ray peak with nonneglible natural line width. CAERI can handle even a complex multiplet consisting of peaks from X-rays and rays in arbitrary mixture, which one often encounters in the isotopic analysis of heavy elements such as U and Pu. (Author)

Open-source implementation of an algorithm for photopeaks search and analysis in gamma-ray spectrometry with semiconductor detectors

International Nuclear Information System (INIS)

Maduar, Marcelo F.; Pecequilo, Brigitte R.S.

2009-01-01

Radioactivity quantification of gamma-ray emitter radionuclides in samples measured by HPGe gamma spectrometers relies on the analysis of the photopeaks present in the spectra, especially on the accurate determination of their net areas. This paper presents a methodology and an algorithm description for the peak search and analysis in order to obtain the relevant peaks parameters and their uncertainties. The procedure is performed on a three step approach: a preliminary search is done by using the second-difference method; experimental peaks widths are assessed in order to obtain a width vs. channel relationship and to define regions with single or overlapping peaks; a non-linear fit is applied to each region of the spectrum with candidate peaks. The final target function is in the form G(x) = B(x) + F(x), where B(x) is the baseline composed by a sum of a weighed left-side B L (x) and right-side B R (x) base-line quadratic functions and the photopeaks term F(x) is a sum of Gaussian functions. The computational implementation is released entirely in open-source license. The code was developed in C++ language and the interface was developed with Qt GUI software toolkit. GNU scientific library, GSL, was employed to perform linear and non-linear fitting procedures as needed. Spectra previously generated at our laboratories were analyzed with the presented methodology and with the commercial software package WinnerGamma. Results obtained are consistent with those obtained with the aforementioned package, suggesting that it could be safely used in general-purpose gamma-ray spectrometry. (author)

Developments in gamma-ray spectrometry: systems, software, and methods-II. 4. High-Performance Digital Gamma-Ray Spectrometry

International Nuclear Information System (INIS)

Michael Momayezi

2001-01-01

This paper reviews recent advances in the field of digital spectrometry made by researchers at X-Ray Instrumentation Associates. All XIA spectrometers are based on a core architecture, which employs digitizing the input signal without shaping and applying all basic data processing in real time to the digital data stream coming out of the wave form digitizer. The real-time digital data processing includes filtering, triggering, pileup rejection, and even pulse shape analysis. In this paper we will describe some of those methods that go beyond emulating a conventional analog system in a digital environment. Rather we will concentrate mainly on methods that have no real equivalent in the analog world. In conventional spectrometers pulse pileup recognition is hardwired and serves a single purpose, namely to reject signals that occur too close to each other to allow for a precise measurement of their amplitude. For a digital device, which can also record wave forms, that would be an unfortunate limitation. The study of very short-lived radioactive isotopes is a case in point. If such an isotope is implanted into a detector in which it then decays by charged particle emission, the signature for the sought-after isotope is that of an implant pulse followed by one or more decay pulses from the isotope and its daughters. If the decay products can be absorbed in the same detector channel, as is the case for proton and alpha emitters in a Si-strip detector, then the isotope decay will show up as a pulse train coming from that detector channel. The difficulty usually is to find the few isotopes of interest amongst a huge background of long-lived or stable isotopes. With programmable pileup recognition logic it is possible to trigger specifically on pulse trains, rather than single pulses, thereby picking out very selectively the isotopes of interest. Analyzing the pulse shape of the incoming preamplifier signal proves to be very useful in many applications. The most obvious

An analysis of the potassium concentrations of soft drinks by HPGe gamma spectrometry

International Nuclear Information System (INIS)

Guillermo Espinosa; Jose-Ignacio Golzarri; Ilsa Hernandez-Ibinarriaga

2009-01-01

Potassium, in a variety of compounds, occurs in abundance in the Earth's crust, and is an essential nutrient for human health. A naturally occurring radioactive isotope of potassium, 40 K, is found in the food and water that we consume. This paper presents the results of a gamma spectrometry analysis of the 40 K concentrations of a selection of commercial soft drinks. The 40 K concentrations are used to calculate the overall potassium concentrations. The analysis was carried out using a hyper-pure germanium (HPGe) detector with Ortec R ASPEC-927 multichannel analyzer module and GammaVision R software. This system was chosen for its high resolution and automatic data processing. The carbonated soft drinks (sodas) Coca-Cola R , Coca-Cola Light R (sold as Diet Coke R in the USA and other countries), Coca-Cola Zero R , Pepsi R , Pepsi Light R , Pepsi Max R , Big Cola R , Lulu-Cola R , Manzana Lift R , Sprite R and Fanta R and the mineral waters Ciel R and Penafiel R were analyzed. These brands are all international registered trademarks. The products analyzed were manufactured and bottled in Mexico. The results show a great variety of potassium concentrations in the different soft drinks analyzed (from 128.0 to 1113.1 mg/L). The concentration of potassium in the sodas, in conjunction with the amounts drank by one person in a year (180 L/year), are high enough to warrant consideration by public health authorities and by people to whom high potassium intakes pose a risk. (author)

Artificial neural networks application for analysis of gamma ray spectrum obtained from the scintillation detectors

International Nuclear Information System (INIS)

Stegowski, Z.

2002-01-01

Scintillation detectors are commonly used for the gamma ray detection. Actually the small peak resolution and the significant Compton effect fraction limit their utilization in the gamma ray spectrometry analysis. This article presents the artificial neural networks (ANN) application to the analysis of the gamma ray spectra acquired from scintillation detectors. The obtained results validate the effectiveness of the ANN method to spectrometry analysis. (author)

The metrological activity determination of 238 U and 230 Th by gamma spectrometry to industrial fuel-cycle application

International Nuclear Information System (INIS)

Almeida M, M.C. de; Delgado, J.U.; Poledna, R.

2006-01-01

This work describes the difficulty for determining the activity of 238 U and 230 Th using gamma spectrometry due to the low gamma-ray emission probabilities of 92 and 67 keV, and, mainly, the associated high uncertainties about 13 and 11%, respectively. 230 Th is a 238 U daughter and it is product from uranium mills and refineries. 230 Th decays to 226 Ra and this decay has to be measured because these radionuclides are not in secular equilibrium with their daughter products, besides the gamma-energies have high uncertainties in the emission probabilities. These radionuclides, mostly 238 U, are important in the nuclear fuel-cycle, since the mining of uranium ore, where the nominal isotopic content of natural uranium is 99.27% of 238 U, until the irradiated fuel reprocessing, where this isotope, a fertile material, is recovered to be used again. The uranium and thorium are considered safeguarded nuclear materials and the metrology tries to calibrate and standardize these materials to improve the activity determination techniques applied in different fuel-cycle scopes. The essential characteristics of the safeguarded materials are low gamma energies (less than 100 keV) and emission probabilities but with high uncertainties. In this way, the metrology can contribute to homeland security defense against illicit nuclear trafficking with the identification and quantification of the safeguarded radionuclides such as uranium and thorium, using specific gamma window energy and high resolution planar or coaxial germanium detector. The efficiency curve is obtained from the reference source spectrum considering the photopeak areas corresponding the standard activities. This curve depends on radiation energy, sample geometry, photon attenuation (sample absorption and material absorption between sample-detector), dead time and sample-detector position. The metrological activity determinations of 238 U solid sources, and of 230 Th, in solution (5 ml flask), were performed using

Application of full spectrum analysis technique for NaI(TI) based gamma ray spectral monitoring system

International Nuclear Information System (INIS)

Pant, Amar D.; Verma, Amit K.; Narayani, K.; Anilkumar, S.; Singh, Rajvir

2016-01-01

NaI(Tl) is commonly used for the gamma spectrometry analysis in laboratories. It continues to be the first choice for gamma spectrometry in many applications even today. Many gamma spectrometric methods are developed to experimentally determine activity of radionuclides in samples. Detectors used worldwide for gamma radiation monitoring are either GM based or scintillator based detector based on count rate. For radiation early warning systems radionuclide specific radiation monitoring methodology is required i.e. gamma ray spectrometry based environmental monitoring system. A computer program has been developed for gamma spectral monitoring by the use of full spectrum analysis (FSA). In this measured spectra are fitted using individual spectral components by least square fitting (LSF). The method is found very useful in situations, where radionuclide specific environmental radiation monitoring is required. The paper describes the details of the FSA procedure for the on line acquisition and analysis of gamma ray spectra from Nal(Tl) detectors

Multivariate statistical approximation of the in situ gamma-ray spectrometry of the State of Zacatecas, Mexico

Energy Technology Data Exchange (ETDEWEB)

Lopez I, J. F.; Rios M, C.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J.L., E-mail: fernandolf498@gmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas, Zac. (Mexico)

2017-09-15

The environmental radioactivity evaluation is a key point in the assessment of the environmental quality. Through this, it can be found possible radioactive contamination, locate possible Uranium and Thorium deposits and evaluate the primordial isotopes concentration due to human activities. A radioactive map of the Zacatecas State, Mexico is under construction based on in situ gamma-ray spectrometry. The present work reports the results of the multivariate statistical approximation of the measured activity data. Based on Pearson correlation, the {sup 228}Ac and {sup 208}Tl activities are statistically significant, while the {sup 214}Bi and {sup 214}Pb activities are not statistically significant. These can be due to the existence or not of secular equilibrium in the Thorium and Uranium series. (Author)

Syntheses of {gamma}-aminobutyric-1-{sup 14}C and of {alpha}-aminoadipic-6-{sup 14}C acid from methoxy-3 chloropropyl-magnesium and marked carbon dioxide; Syntheses de l'acide {gamma}-aminobutyrique{sup 14}C-1 et de l'acide {alpha}-aminoadipique {sup 14}C-6 a partir de methoxy-3 chloropropylmagnesium et d'anhydride carbonique marque

Energy Technology Data Exchange (ETDEWEB)

Liem, Phung Nhu [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, Departement des radioelements, Service des molecules marquees

1967-04-01

Carbonation of {gamma}-methoxypropyl-magnesium chloride by CO{sub 2} gives {gamma}-methoxy-butyric carboxylic-{sup 14}C acid with a yield of about 95 per cent. When the latter is treated successively with anhydrous HBr and with diazomethane, methyl carboxylic {gamma}-bromobutyrate-{sup 14}C is formed. This in turn gives {gamma}-amino-butyric carboxylic-{sup 14}C acid with an overall yield of 66 per cent with respect to Ba{sup 14}CO{sub 3}, when it is condensed with potassium phthalimide and hydrolyzed by acid. By reacting methyl-{gamma}-bromobutyrate-{sup 14}C with the sodium derivative of ethyl cyanacetamido-acetate in ethanol, followed by an acid hydrolysis, {alpha}-aminoadipic-6-{sup 14}C acid is obtained with an overall yield of 46 per cent with respect to Ba{sup 14}CO{sub 3}. (author) [French] La carbonatation du chlorure de {gamma}-methoxypropylmagnesium par {sup 14}CO{sub 2} donne l'acide {gamma}-methoxybutyrique carboxyle {sup 14}C avec un rendement d'environ 95 pour cent. Ce dernier traite successivement par HBr anhydre et par le diazomethane conduit au {gamma}-bromobutyrate de methyle carboxyle {sup 14}C. Celui-ci condense avec le phtalimide de potassium suivi d'une hydrolyse acide fournit l'acide {gamma}-aminobutyrique carboxyle {sup 14}C avec un rendement global de 66 pour cent par rapport a Ba{sup 14}CO{sub 3}. L'action du {gamma}-bromobutyrate de methyle {sup 14}C sur le derive sode du cyanacetamidoacetate d'ethyle dans l'ethanol suivie d'hydrolyse acide donne l'acide {alpha}-aminoadipique {sup 14}C-6 avec un rendement global de 46 pour cent par rapport a Ba{sup 14}CO{sub 3}. (auteur)

Recent progress in low-level gamma imaging

International Nuclear Information System (INIS)

Mahe, C.; Girones, Ph.; Lamadie, F.; Le Goaller, C.

2007-01-01

The CEA's Aladin gamma imaging system has been operated successfully for several years in nuclear plants and during decommissioning projects with additional tools such as gamma spectrometry detectors and dose rate probes. The radiological information supplied by these devices is becoming increasingly useful for establishing robust and optimized decommissioning scenarios. Recent technical improvements allow this gamma imaging system to be operated in low-level applications and with shorter acquisition times suitable for decommissioning projects. The compact portable system can be used in places inaccessible to operators. It is quick and easy to implement, notably for onsite component characterization. Feasibility trials and in situ measurements were recently carried out under low-level conditions, mainly on waste packages and glove boxes for decommissioning projects. This paper describes recent low-level in situ applications. These characterization campaigns mainly concerned gamma emitters with γ energy < 700 keV. In many cases, the localization of hot spots by gamma camera was confirmed by additional measurements such as dose rate mapping and gamma spectrometry measurements. These complementary techniques associated with advanced calculation codes (MCNP, Mercure 6.2, Visiplan and Siren) offer a mobile and compact tool for specific assessment of waste packages and glove boxes. (authors)

A broadband gamma-ray spectrometry using novel unfolding algorithms for characterization of laser wakefield-generated betatron radiation

Energy Technology Data Exchange (ETDEWEB)

Jeon, Jong Ho, E-mail: jhjeon07@ibs.re.kr; Nakajima, Kazuhisa, E-mail: naka115@dia-net.ne.jp; Pathak, Vishwa Bandhu; Cho, Myung Hoon; Yoo, Byung Ju; Shin, Kang Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Kim, Hyung Taek; Sung, Jae Hee; Lee, Seung Ku; Choi, Il Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Rhee, Yong Joo [Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Shin, Jung Hun; Jo, Sung Ha [Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Hojbota, Calin; Cho, Byeoung Ick; Nam, Chang Hee [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 500-712 (Korea, Republic of)

2015-12-15

We present a high-flux, broadband gamma-ray spectrometry capable of characterizing the betatron radiation spectrum over the photon energy range from 10 keV to 20 MeV with respect to the peak photon energy, spectral bandwidth, and unique discrimination from background radiations, using a differential filtering spectrometer and the unfolding procedure based on the Monte Carlo code GEANT4. These properties are experimentally verified by measuring betatron radiation from a cm-scale laser wakefield accelerator (LWFA) driven by a 1-PW laser, using a differential filtering spectrometer consisting of a 15-filter and image plate stack. The gamma-ray spectra were derived by unfolding the photostimulated luminescence (PSL) values recorded on the image plates, using the spectrometer response matrix modeled with the Monte Carlo code GEANT4. The accuracy of unfolded betatron radiation spectra was assessed by unfolding the test PSL data simulated with GEANT4, showing an ambiguity of less than 20% and clear discrimination from the background radiation with less than 10%. The spectral analysis of betatron radiation from laser wakefield-accelerated electron beams with energies up to 3 GeV revealed radiation spectra characterized by synchrotron radiation with the critical photon energy up to 7 MeV. The gamma-ray spectrometer and unfolding method presented here facilitate an in-depth understanding of betatron radiation from LWFA process and a novel radiation source of high-quality photon beams in the MeV regime.

Radiological Mapping of the Alkaline Intrusive Complex of Jombo, South Coastal Kenya by In-Situ Gamma-Ray Spectrometry

Science.gov (United States)

Kaniu, Ian; Darby, Iain G.; Kalambuka Angeyo, Hudson

2016-04-01

Carbonatites and alkaline intrusive complexes are rich in a variety of mineral deposits such as rare earth elements (REEs), including Nb, Zr and Mn. These are often associated with U and Th bearing minerals, including monazite, samarskite and pyrochlore. Mining waste resulting from mineral processing activities can be highly radioactive and therefore poses a risk to human health and environment. The Jombo complex located in Kenya's south coastal region is potentially one of the richest sources of Nb and REEs in the world. It consists of the main intrusion at Jombo hill, three associated satellite intrusions at Mrima, Kiruku and Nguluku hills, and several dykes. The complex is highly heterogeneous with regard to its geological formation as it is characterized by alkaline igneous rocks and carbonatites which also influence its radio-ecological dynamics. In-situ gamma spectrometry offers a low-cost, rapid and spatially representative radioactivity estimate across a range of landscapes compared to conventional radiometric techniques. In this work, a wide ranging radiological survey was conducted in the Jombo complex as follow up on previous studies[1,2], to determine radiation exposure levels and source distributions, and perform radiological risk assessments. The in-situ measurements were carried out using a 2.0 l NaI(Tl) PGIS-2 portable detector from Pico Envirotec Inc integrated with GPS, deployed for ground (back-pack) and vehicular gamma-ray spectrometry. Preliminary results of radiological distribution and mapping will be presented. [1] Patel, J. P. (1991). Discovery and Innovation, 3(3): 31-35. [2] Kebwaro, J. M. et. al. (2011). J. Phys. Sci., 6(13): 3105-3110.

In situ gamma spectrometry aspects of an European intercomparison of national networks used to provide early warning of a nuclear accident

International Nuclear Information System (INIS)

Gurriaran, R.; Lemercier, M.; Bouisset, P.; Cagnat, X.; Saez-Vergara, J. C.; Tyler, A. N.

2006-01-01

In 2002, the EURADOS Working Group on Environmental Monitoring organised the second European intercomparison exercise of national network systems used to provide early warning in case of a nuclear accident. The aim of the exercise is to ensure consistent and comparable results reported by different countries during a nuclear accident, hence avoiding that the dose rate measurements reported present steps at national borders due to different calibrations or different measurement quantities being used. The exercise studied the response of the detectors to different situations: Free field site, a flat area covered with grass. The detectors where in presence of environmental radiation and point sources. Radioactive plume simulator. An incident was simulated by gradually increasing the ambient dose rate by values up to 50% of the normal value. Cosmic radiation site. A platform installed in the middle of a lake permitted to study the response of detectors to cosmic rays in the absence of other components. Ultra low background laboratory (UDO). Situated at 925 m in a salt mine this unique facility has a very low ambient dose (<1 nSv/h) and permitted the study of the response of detectors to collimated beams, in the absence of other components. The exercise was focused on the systems that continuously monitor the ambient dose rate but a novelty in the 2002 intercomparison was the participation of in situ gamma spectrometry teams. This presentation will focus on the in situ gamma spectrometry aspects: The interest of having the energy spectra information in order to discriminate the different contributors to the ambient dose, and the work that has been done in order to ensure an agreement between the dosimetry aspects and the spectrometry results

Study of radionuclide and element characterization of Angola marine sediment using low background gamma spectrometry and instrumental neutron activation analysis techniques

International Nuclear Information System (INIS)

Teixeira, M.C.P.; Vuong Huu Tan; Truong Y; Ho Manh Dung; Le Nhu Sieu; Cao Dong Vu; Nguyen Thanh Binh

2007-01-01

The concentrations of radionuclides and chemical elements in Angola marine sediment samples were determined by using low background gamma (LBG) spectrometry and instrumental neutron activation analysis (INAA). The combination of radionuclide and elemental concentration values yielded synergy in the validation of analytical data and identification of sediment sources modeled by multivariate factor analysis. Varimax rotation factor analysis based on the elemental concentrations revealed five sources contributed to the sediment composition, i.e. crustal, sea-salt, industrial, coal-related and Se-related sources. (author)

ICIT contribution to JET gamma-ray diagnostics enhancement

International Nuclear Information System (INIS)

Soare, S.; Curuia, M.; Zoita, V.

2010-01-01

Full text: Gamma-ray emission of tokamak plasmas is the result of the interaction of fast ions (fusion reaction products, including alpha particles, NBI ions, ICRH-accelerated ions) with main plasma impurities (e.g., carbon, beryllium). Gamma-ray diagnostics involve both gamma-ray imaging (cameras) and gamma-ray spectrometry (spectrometers). For the JET tokamak, gamma-ray diagnostics have been used to provide information on the characteristics of the fast ion population in plasmas. Two gamma-ray diagnostics enhancements project have been launched by JET and the MEdC/EURATOM Association has agreed to lead both of them with ICIT as projects leader. (authors)

Evaluation of an automated assay system to measure soil radionuclides by L x-ray and gamma-ray spectrometry

International Nuclear Information System (INIS)

Nyhan, J.W.; Drennon, B.J.; Crowell, J.M.

1982-08-01

An automated radionuclide assay system for conducting soil radioassays using L x-ray and gamma-ray spectrometry was evaluated. Wet chemistry assay procedures were shown to be considerably more time consuming than similar analyses of soil on this radionuclide assay system. The detection limits of 241 Am and plutonium were determined, as well as the reproducibility of radionuclide assay results. The L x-ray spectrometric measurements were compared with radiochemical analyses on several tuff samples. The assay system's intrinsic germanium detector was found to respond linearly to varying low concentrations of 241 Am and plutonium, both of which were easily detected in the presence of elevated concentrations of 137 Cs

Contribution to the study of the geophysical behaviour of lead-210 by application of alpha spectrometry; Contribution a l'etude du comportement geophysique du plomb 210 par application de la spectrometrie alpha

Energy Technology Data Exchange (ETDEWEB)

Nezami, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-06-01

A study of the changes in the lead-210 contents of rain-water and of water produced by melting polar ice has required the development of a method for dosing lead-210, an {alpha} emitter. This method is 40 times more sensitive than that which measures the lead-210 by bismuth-210, a ({beta} emitter. The first part of the report presents the study of a spectrometry using semiconductor detectors; a catalogue of a spectra shows the advantages of this method. In the second part will be found at first a new chemical separation method for polonium-210 and the results obtained with this method. The main results obtained on the geophysical behaviour of lead-210 are the following: - the monthly lead-210 and polonium-210 contents in rain water are approximately constant with time. - in the Gif-sur-Yvette region, the clean-up by 'dry fall-out' can attain 40 to 50 per cent of the total fall-out. - a study of Antarctic ice samples makes it possible to determine an annual accumulation rate equivalent to 13.8 cm of water and to show discrepancies in the periodic concentrations which correspond to the latest maxima of solar activity. - a balance is drawn up between the radon produced by the continents and the lead-210 fall-out. (author) [French] Une etude sur les variations de la teneur en plomb 210 des eaux de pluie et des eaux de fusion des glaces polaires a necessite la mise au point d'une methode de dosage du plomb 210 emetteur {alpha}. Cette methode permet d'obtenir une sensibilite quarante fois superieure a celle dosant le plomb 210 par le bismuth 210 emetteur {beta}. La premiere partie du travail presente l'etude de la spectrometrie {alpha} par detecteur a semiconducteurs, un catalogue de spectres {alpha} met en evidence les avantages de cette methode. Dans la deuxieme partie on trouvera en premier lieu une nouvelle methode chimique de separation du polonium 210 ainsi que les resultats obtenus grace a cette methode. Les principaux resultats sur le comportement geophysique du

Simultaneous Determination of 30 Trace Elements in Cancerous and Noncancerous Human Tissue Samples with Gamma-ray Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Samsahl, K; Brune, D; Wester, P O

1963-10-15

The following trace elements were quantitatively determined by gamma-ray spectrometry in T samples of non-cancerous and 5 samples of cancerous human tissue: P, Ca, Cr, Fe, Co, Cu, Zn, As, Se, Br, Rb, Mo, Ag, Cd, Sb, Cs, La, Au, and Hg. In some of the samples the following elements were qualitatively determined: Ti+Sc, Ga, Sr, In, Ba, Ce, Hf, Os, Pt, and U. Most of the trace elements were found to be present in much higher concentrations in the non-cancerous than in the corresponding cancerous liver samples. In a typical run one sample each of cancerous and non-cancerous tissue was irradiated together with standards of the elements to be determined in a thermal flux of 2.10{sup 13} n/cm{sup 2}/sec. for 24 hours. The radioactive trace elements were separated into 16, and in some cases 18, groups by means of a chemical group separation method. Subsequently, the gamma spectrometric measurements were performed. Two persons can manage the chemical separations and measure the different activities from a run in 1,5 days. A new method of comparing unknown samples with standards was developed.

An optimum analysis sequence for environmental gamma-ray spectrometry

International Nuclear Information System (INIS)

De la Torre, F.; Rios M, C.; Ruvalcaba A, M. G.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L.

2010-10-01

This work aims to obtain an optimum analysis sequence for environmental gamma-ray spectroscopy by means of Genie 2000 (Canberra). Twenty different analysis sequences were customized using different peak area percentages and different algorithms for: 1) peak finding, and 2) peak area determination, and with or without the use of a library -based on evaluated nuclear data- of common gamma-ray emitters in environmental samples. The use of an optimum analysis sequence with certified nuclear information avoids the problems originated by the significant variations in out-of-date nuclear parameters of commercial software libraries. Interference-free gamma ray energies with absolute emission probabilities greater than 3.75% were included in the customized library. The gamma-ray spectroscopy system (based on a Ge Re-3522 Canberra detector) was calibrated both in energy and shape by means of the IAEA-2002 reference spectra for software intercomparison. To test the performance of the analysis sequences, the IAEA-2002 reference spectrum was used. The z-score and the reduced χ 2 criteria were used to determine the optimum analysis sequence. The results show an appreciable variation in the peak area determinations and their corresponding uncertainties. Particularly, the combination of second derivative peak locate with simple peak area integration algorithms provides the greater accuracy. Lower accuracy comes from the combination of library directed peak locate algorithm and Genie's Gamma-M peak area determination. (Author)

Gamma ray spectrometry results from core samples collected for RESUME 95

Energy Technology Data Exchange (ETDEWEB)

Sanderson, D.C.W.; Allyson, J.D. [SURRC, East Kilbride, Scotland (United Kingdom); Toivonen, H.; Honkamaa, T. [STUK, Helsinki (Finland)

1997-12-31

Field sampling of an airfield at Vesivehmaa, near Vaeaeksy, Finland (Area I) was carried out between 26-29 May 1995, to establish the radionuclide deposition and inventory of Chernobyl derived {sup 137}Cs, and natural radionuclides. The objective was to establish a common calibration site for in-situ and airborne gamma spectrometers, for Exercise RESUME 95 conducted in August 1995. The report presents the sampling details, handling and treatment. The analyses are discussed with particular emphasis given to {sup 137}Ca, {sup 134}Cs, {sup 40}K, {sup 214}Bi and {sup 208} radionuclides, and the quantification of their respective deposition and inventories. The results have been used to estimate the effective concentrations of nuclides at the calibration site for in-situ and airborne gamma spectrometry, and the depth distribution. For {sup 137}Cs the weighted mean activity per unit area takes on values of 50.7{+-}5.2 kBq m{sup -2} at 1 m ground clearance, 51.1{+-}6.9 kBq m{sup -2} at 50 m height and 47.9{+-}8.5 kBq m{sup -2} at 100 m. The similarity of these values confirms the suitability of the Vesivehmaa site for comparison of in-situ and airborne results despite variations of a factor of two between results from individual cores. The mean {alpha}/{rho} value for {sup 137}Cs in Area I is 0.77{+-}0.10 cm{sup 2}g{sup -1} (relaxation mass per unit area, {beta} 1.31{+-}0.15 gcm{sup -2}). Additional soil sampling across parts of Area II (a 6x3 km area selected for mapping Chernobyl deposition) was carried out. The mean level of {sup 137}Cs activity from these samples was 92.4{+-}63 kBq m{sup -2}, a sample taken near Laihansuo showing the largest value obtained at 172 kBq m{sup -2}. (EG). 17 refs.

Gamma ray spectrometry results from core samples collected for RESUME 95

Energy Technology Data Exchange (ETDEWEB)

Sanderson, D C.W.; Allyson, J D [SURRC, East Kilbride, Scotland (United Kingdom); Toivonen, H; Honkamaa, T [STUK, Helsinki (Finland)

1998-12-31

Field sampling of an airfield at Vesivehmaa, near Vaeaeksy, Finland (Area I) was carried out between 26-29 May 1995, to establish the radionuclide deposition and inventory of Chernobyl derived {sup 137}Cs, and natural radionuclides. The objective was to establish a common calibration site for in-situ and airborne gamma spectrometers, for Exercise RESUME 95 conducted in August 1995. The report presents the sampling details, handling and treatment. The analyses are discussed with particular emphasis given to {sup 137}Ca, {sup 134}Cs, {sup 40}K, {sup 214}Bi and {sup 208} radionuclides, and the quantification of their respective deposition and inventories. The results have been used to estimate the effective concentrations of nuclides at the calibration site for in-situ and airborne gamma spectrometry, and the depth distribution. For {sup 137}Cs the weighted mean activity per unit area takes on values of 50.7{+-}5.2 kBq m{sup -2} at 1 m ground clearance, 51.1{+-}6.9 kBq m{sup -2} at 50 m height and 47.9{+-}8.5 kBq m{sup -2} at 100 m. The similarity of these values confirms the suitability of the Vesivehmaa site for comparison of in-situ and airborne results despite variations of a factor of two between results from individual cores. The mean {alpha}/{rho} value for {sup 137}Cs in Area I is 0.77{+-}0.10 cm{sup 2}g{sup -1} (relaxation mass per unit area, {beta} 1.31{+-}0.15 gcm{sup -2}). Additional soil sampling across parts of Area II (a 6x3 km area selected for mapping Chernobyl deposition) was carried out. The mean level of {sup 137}Cs activity from these samples was 92.4{+-}63 kBq m{sup -2}, a sample taken near Laihansuo showing the largest value obtained at 172 kBq m{sup -2}. (EG). 17 refs.

Gamma ray doses proceeding from natural occurring radionuclides in closed environments

International Nuclear Information System (INIS)

Aguiar, Vitor Angelo P. de; Medina, Nilberto H.; Silveira, Marcilei A. Guazzelli da; Moreira, Ramon H.

2009-01-01

In this work we report on the application of gamma-ray spectrometry in the study of the effective dose coming from terrestrial natural elements present in building materials such as sand, cement, lime (CaO) and milled granitic stones. The major contribution to annual gamma-ray radiation effective dose is due to the natural occurring radionuclides 40 K, 232 Th and 238 U. Two spectrometry systems were employed to measure the gamma radiation: one with a 60% efficient GeHP detector and the second one with a 2''x2'' NaI(Tl) scintillator. The estimated effective dose coming from the three reference rooms assumed is 0.63 mSv/yr, proceeding from terrestrial natural elements. The principal gamma radiation sources are cement, sand and bricks. (author)

Significance of radioelement concentration measurements made by airborne gamma-ray spectrometry over the Canadian Shield

International Nuclear Information System (INIS)

Charbonneau, B.W.; Killeen, P.G.; Carson, J.M.; Cameron, G.W.; Richardson, K.A.

1976-01-01

Results of airborne gamma-ray spectrometer surveys conducted by the Geological Survey of Canada are presented as maps contoured in units of radioelement and concentration ratios. These contoured values represent the average surface concentrations of the radioelements over areas of the order of several square kilometres. The relationship between this ''average surface concentration'' and the radioelement concentration in bedrock underlying the area depends on: (1) the percentage of outcrop; (2) the relation between overburden and bedrock radioelement concentration; (3) percentage of marshland or surface water in the area; (4) soil moisture; and (5) density of vegetation. More than 2500 portable gamma-ray spectrometer analyses of outcrop and overburden have been made in the Bancroft, Elliot Lake and Fort Smith areas of the Canadian Precambrian Shield. In the areas examined, the radioelement concentrations in glacial drift reflect the concentrations in the underlying bedrock. Rocks with near-crustal average contents of thorium, uranium and potassium are overlain by glacial drift having approximately the same concentrations. As the concentration in bedrock increases, the concentration in the local overburden also increases, but not to the same extent. In addition, in-situ gamma-ray spectrometry measurements were made at almost 1000 stations within the area of airborne surveys near Mont Laurier and Elliot Lake. These ground measurements were compared with the airborne measurements by averaging the values for all those ground stations located in the areas between each contour level on airborne maps. Radioelement concentrations in bedrock are considerably higher than corresponding airborne measurements, and this difference between bedrock and airborne values increases at higher radioelement concentrations. Radioelement concentrations in glacial drift are only slightly higher than airborne contour values for the same area. Airborne contour maps of the radioelement ratios

Automated complex for information retrieval and processing in the gamma-resonance spectrometry

International Nuclear Information System (INIS)

Belogurov, V.N.; Bylinkin, V.A.

1977-01-01

A complex for information retrieval and processing in the Moessbauer effect spectrometry is described. The complex consists of a set of 4 precision spectrometers nad a program system for the computation of Moessbauer effect spectrum. High velocity accuracy - 0.004 mm/s during 6 months operation is achieved by introducing an additional negative feedback, the signal from which is obtained when the time of electromagnetic vibrator driving rod passage in the middle of the cycle is compared to the half-period length of the operation of the multichannel analyser address register. Information from 4 spectrometers via a commutation unit and an equalizer unit is analyzed by one analyser. Descriptions and schemes of spectrometers, procedure and scheme of calibration and checking of their operation are given. Described are the system of connection of spectrometers with the BESM-4 computer and the program complex including programs of information input, check-up,, correction and storage in the computer, the calibration of the spectrometer velocity scale and the programs for computing gamma-resonance spectra. The description of the operational principles of these programs and their block diagrams is given

Study of principle error sources in gamma spectrometry. Application to cross sections measurement

International Nuclear Information System (INIS)

Majah, M. Ibn.

1985-01-01

The principle error sources in gamma spectrometry have been studied in purpose to measure cross sections with great precision. Three error sources have been studied: dead time and pile up which depend on counting rate, and coincidence effect that depends on the disintegration scheme of the radionuclide in question. A constant frequency pulse generator has been used to correct the counting loss due to dead time and pile up in cases of long and short disintegration periods. The loss due to coincidence effect can reach 25% and over, depending on the disintegration scheme and on the distance source-detector. After establishing the correction formula and verifying its validity for four examples: iron 56, scandium 48, antimony 120 and gold 196 m, an application has been done by measuring cross sections of nuclear reactions that lead to long disintegration periods which need short distance source-detector counting and thus correcting the loss due to dead time effect, pile up and coincidence effect. 16 refs., 45 figs., 25 tabs. (author)

An optimum analysis sequence for environmental gamma-ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

De la Torre, F.; Rios M, C.; Ruvalcaba A, M. G.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L., E-mail: fta777@hotmail.co [Universidad Autonoma de Zacatecas, Centro Regional de Estudis Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

2010-10-15

This work aims to obtain an optimum analysis sequence for environmental gamma-ray spectroscopy by means of Genie 2000 (Canberra). Twenty different analysis sequences were customized using different peak area percentages and different algorithms for: 1) peak finding, and 2) peak area determination, and with or without the use of a library -based on evaluated nuclear data- of common gamma-ray emitters in environmental samples. The use of an optimum analysis sequence with certified nuclear information avoids the problems originated by the significant variations in out-of-date nuclear parameters of commercial software libraries. Interference-free gamma ray energies with absolute emission probabilities greater than 3.75% were included in the customized library. The gamma-ray spectroscopy system (based on a Ge Re-3522 Canberra detector) was calibrated both in energy and shape by means of the IAEA-2002 reference spectra for software intercomparison. To test the performance of the analysis sequences, the IAEA-2002 reference spectrum was used. The z-score and the reduced {chi}{sup 2} criteria were used to determine the optimum analysis sequence. The results show an appreciable variation in the peak area determinations and their corresponding uncertainties. Particularly, the combination of second derivative peak locate with simple peak area integration algorithms provides the greater accuracy. Lower accuracy comes from the combination of library directed peak locate algorithm and Genie's Gamma-M peak area determination. (Author)

The use of difference spectra with a filtered rolling average background in mobile gamma spectrometry measurements

International Nuclear Information System (INIS)

Cresswell, A.J.; Sanderson, D.C.W.

2009-01-01

The use of difference spectra, with a filtering of a rolling average background, as a variation of the more common rainbow plots to aid in the visual identification of radiation anomalies in mobile gamma spectrometry systems is presented. This method requires minimal assumptions about the radiation environment, and is not computationally intensive. Some case studies are presented to illustrate the method. It is shown that difference spectra produced in this manner can improve signal to background, estimate shielding or mass depth using scattered spectral components, and locate point sources. This approach could be a useful addition to the methods available for locating point sources and mapping dispersed activity in real time. Further possible developments of the procedure utilising more intelligent filters and spatial averaging of the background are identified.

Spectrometry techniques for radioactivity measurements

International Nuclear Information System (INIS)

Anilkumar, S.

2016-01-01

The energy of the radiation emission following the nuclear decay is unique and the characteristic of the radio nuclide which undergoes decay. Thus measurement of the energy of the radiation offers a method of identifying the radio nuclides. The prime requirement of the energy measurement is a suitable detector which shows response proportional to the energy of the radiation rather than the presence of the radiation. The response from such detectors are suitably processed and distributed with respect to the signal strength which is proportional to incident energy. This distribution is normally referred as energy spectrum and is recorded in the multichannel analyser. The measurement of energy and intensity of radiation from the spectrum is called radiation spectrometry. Thus the radiation spectrometry allows the identification and quantification of radioactive isotopes in variety of matrices. The radiation spectrometry has now become a popular radioanalytical technique in wide area of nuclear fuel cycle programs. The popular spectrometry techniques commonly used for the radioactivity measurement and analysis are Alpha spectrometry, Gamma ray spectrometry and Beta spectrometry

Contribution to the study of the sintering mechanisms of uranium powders in the {alpha}, {beta}, and {gamma} phases; Contribution a l'etude des mecanismes de frittage de poudre d'uranium en phases {alpha}, {beta}, et {gamma}

Energy Technology Data Exchange (ETDEWEB)

Pinteau, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-06-01

also followed by simple and differential thermal analysis. (author) [French] L'etude des mecanismes de frittage de poudre d'uranium d'origine caliothermique a ete effectuee sous vide par mesure dilatometrique en continu des retraits d'echantillons prealablement comprimes a temperature ordinaire sous atmosphere d'argon purifie. Les essais effectues dans les trois domaines {alpha}, {beta}, {gamma} ont permis de constater que le premier stade de frittoge semble regi par un mecanisme d'autodiffusion en volume; les valeurs des chaleurs d'activation des mecanismes de frittage trouves sont voisines de celles deduites lors des etudes sur l'autodiffusion en volume par la methode directe des radiotraceurs. Par ailleurs, dans le domaine {gamma} on a pu mettre en evidence un second mecanisme de frittage qui interesse des durees de frittage beaucoup plus longues, a chaleur d'activation beaucoup plus faible semblant indiquer qu'il s'agit d'un mecanisme d'elimination des pores par diffusion intergranulaire de lacunes. En outre, les essois dilatometriques permettent de mettre en evidence l'influence simultanee de deux facteurs principaux regissant cette etude: les joints de grains et les coefficients de diffusion. Dans une seconde partie, les echantillons frittes ont ete etudies par diverses methodes afin de determiner leur structure et certaines de leurs proprietes physiques. C'est ainsi que des examens metallographiques effectues apres polissage par bombardement ionique ont permis de determiner l'evolution de la porosite dans les trois phases {alpha}, {beta} et {gamma} ainsi que la structure et la nature des inclusions dans chaque echantillon. Par ailleurs des mesures de densite et de porosite ont ete effectuees. L'evolution des deux series de resultats permet de confirmer les examens dilatometriques et micrographiques precedents. Enfin, une etude dilatometrique detaillee des echantillons frittes en phose {gamma} a permis de montrer l'influence des couches d'oxyde associees a la

Analysis by {alpha} spectrometry (chamber with a grid). Proserpine (1960); Analyses par spectrometrie {alpha} (chambre a grille). Proserpine (1960)

Energy Technology Data Exchange (ETDEWEB)

Clouet d' Orval, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The aim is to compare various substances in an electrolytic deposit by means of their {alpha} radiation. The energies are separated by counting in a chamber with a grid, specially designed for the analysis of plutonium. A resolution of 1.7 per cent is normally obtained for plutonium bands. {sup 239}Pu-{sup 233}Pu, {sup 239}Pu-{sup 238}Pu mixtures have been analysed by this method. (author) [French] Il s'agit de comparer, au moyen de leur rayonnement {alpha}, divers corps contenus dans un depot electrolytique. On separe les energies par comptage dans une chambre a grille, specialement concue pour analyser du plutonium. On obtient couramment une resolution de 1,7 pour cent, pour des raies du plutonium. On a pu faire, par cette methode, l'analyse de melanges {sup 239}Pu-{sup 233}Pu et {sup 239}Pu-{sup 238}Pu. (auteur)

Contribution to the study of the geophysical behaviour of lead-210 by application of alpha spectrometry; Contribution a l'etude du comportement geophysique du plomb 210 par application de la spectrometrie alpha

Energy Technology Data Exchange (ETDEWEB)

Nezami, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-06-01

A study of the changes in the lead-210 contents of rain-water and of water produced by melting polar ice has required the development of a method for dosing lead-210, an {alpha} emitter. This method is 40 times more sensitive than that which measures the lead-210 by bismuth-210, a ({beta} emitter. The first part of the report presents the study of a spectrometry using semiconductor detectors; a catalogue of a spectra shows the advantages of this method. In the second part will be found at first a new chemical separation method for polonium-210 and the results obtained with this method. The main results obtained on the geophysical behaviour of lead-210 are the following: - the monthly lead-210 and polonium-210 contents in rain water are approximately constant with time. - in the Gif-sur-Yvette region, the clean-up by 'dry fall-out' can attain 40 to 50 per cent of the total fall-out. - a study of Antarctic ice samples makes it possible to determine an annual accumulation rate equivalent to 13.8 cm of water and to show discrepancies in the periodic concentrations which correspond to the latest maxima of solar activity. - a balance is drawn up between the radon produced by the continents and the lead-210 fall-out. (author) [French] Une etude sur les variations de la teneur en plomb 210 des eaux de pluie et des eaux de fusion des glaces polaires a necessite la mise au point d'une methode de dosage du plomb 210 emetteur {alpha}. Cette methode permet d'obtenir une sensibilite quarante fois superieure a celle dosant le plomb 210 par le bismuth 210 emetteur {beta}. La premiere partie du travail presente l'etude de la spectrometrie {alpha} par detecteur a semiconducteurs, un catalogue de spectres {alpha} met en evidence les avantages de cette methode. Dans la deuxieme partie on trouvera en premier lieu une nouvelle methode chimique de separation du polonium 210 ainsi que les resultats obtenus grace a cette methode. Les principaux resultats sur le

Precision measurement of radioactivity in gamma-rays spectrometry using two HPGe detectors (BEGe-6530 and GC0818-7600SL models comparison techniques: Application to the soil measurement

Directory of Open Access Journals (Sweden)

Guembou Shouop Cebastien Joel

2017-01-01

• Proved that the activity concentration determination in gamma spectrometry depended on the energy range emitted by a radionuclide. This study showed that the standard deviation measurement was less important to the result realized with BEGe-6530 HPGe model. Our findings were demonstrated that the results of the Broad Energy Germanium detector were more reliable.

Airborne gamma spectrometry measurements in the context of the exercise ARM02

International Nuclear Information System (INIS)

Bucher, B.; Rybach, L.; Schwarz, G.; Baerlocher, C.

2003-05-01

The international exercise under the European Union project ECCOMAGS (European Coordination and Calibration of Mobile and Airborne Gamma Spectrometry) stood in the centre of the yearly airborne gamma spectrometry measurement flights which were carried out in the time of 27 -31 May 2002. The exercise was held in Southwest Scotland in the region of Dumfries and Galloway. Unfortunately due to difficulties with flight approvals for military aircrafts data could be taken in the exercise area only on the flight back to Switzerland. Immediately after returning to Switzerland the regular measurements around the nuclear power plants Beznau (KKB) and Leibstadt (KKL), around the intermediate storage facilities for radioactive waste (ZWILAG) and around the research facility Paul Scherrer Institute were performed. The flights took place in the context of the exercise ARM02 and were lead by the Swiss National Emergency Operations Centre (NAZ). Unfortunately just a few measurements in the common intercalibration areas could be taken on the flight back from the international exercise. Nevertheless comparisons of the results with those of other European teams could be made. These comparisons proved the good calibration of our equipment. On the flight back measurements were also carried out at great altitude above the sea. This data allowed to determine very well the background of the aircraft and the cosmic stripping ratios. In the context of the regular measurements in the environs of the nuclear facilities in Switzerland the areas around the nuclear power plants Beznau and Leibstadt and around the nuclear research facility Paul Scherrer Institute were measured. The results were very similar to the results of earlier measurements in the last years. The nuclear power plant Beznau couldn't be recognised on the activity maps. But the nuclear power plant Leibstadt could be identified by its direct radiation which is specific for this type of reactor (BWR). At the site of the Paul

On background radiation gradients – the use of airborne surveys when searching for orphan sources using mobile gamma-ray spectrometry

International Nuclear Information System (INIS)

Kock, Peder; Rääf, Christopher; Samuelsson, Christer

2014-01-01

Systematic background radiation variations can lead to both false positives and failures to detect an orphan source when searching using car-borne mobile gamma-ray spectrometry. The stochastic variation at each point is well described by Poisson statistics, but when moving in a background radiation gradient the mean count rate will continually change, leading to inaccurate background estimations. Airborne gamma spectrometry (AGS) surveys conducted on the national level, usually in connection to mineral exploration, exist in many countries. These data hold information about the background radiation gradients which could be used at the ground level. This article describes a method that aims to incorporate the systematic as well as stochastic variations of the background radiation. We introduce a weighted moving average where the weights are calculated from existing AGS data, supplied by the Geological Survey of Sweden. To test the method we chose an area with strong background gradients, especially in the thorium component. Within the area we identified two roads which pass through the high-variability locations. The proposed method is compared with an unweighted moving average. The results show that the weighting reduces the excess false positives in the positive background gradients without introducing an excess of failures to detect a source during passage in negative gradients. -- Highlights: • We present a simple method to account for gradients in the natural background radiation. • Gradients in the natural radiation background can be modelled at the ground level using AGS data. • The number of false positives due to background gradients can be reduced by using airborne data

Development of an open source software of quantitative analysis for radionuclide determination by gamma-ray spectrometry using semiconductor detectors

International Nuclear Information System (INIS)

Maduar, Marcelo Francis

2010-01-01

Radioactivity quantification of gamma-ray emitter radionuclides in samples measured by HPGe gamma-ray spectrometry relies on the analysis of the photopeaks present in the spectra, especially on the accurate determination of their net areas. Such a task is usually performed with the aid of proprietary software tools. This work presents a methodology, algorithm descriptions and an open source application, called OpenGamma, for the peak search and analysis in order to obtain the relevant peaks parameters and radionuclides activities. The computational implementation is released entirely in open-source license for the main code and with the use of open software packages for interface design and mathematical libraries. The procedure for the peak search is performed on a three step approach. Firstly a preliminary search is done by using the second-difference method, consisting in the generation of a derived spectrum in order to find candidate peaks. In the second step, the experimental peaks widths are assessed and well formed and isolated ones are chosen to obtain a FWHM vs. channel relationship, by application of the Levenberg-Marquardt minimization method for non-linear fitting. Lastly, regions of the spectrum with grouped peaks are marked and a non-linear fit is again applied to each region to obtain baseline and photopeaks terms; from these terms, peaks net areas are then assessed. (author)

Analysis of radionuclide mixtures by {alpha}-{gamma} and {beta}-{gamma} coincidences using a simple device; Analyse de melanges de radionucleides par un dispositif simple de coincidences {alpha}-{gamma} et {beta}-{gamma}

Energy Technology Data Exchange (ETDEWEB)

Pottier, R; Berger, R [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (France)

1966-06-01

A procedure is described for the qualitative and quantitative spectrographic analysis of radioactive sources containing two alpha-gamma emitters having the same alpha energy or two beta-gamma emitters having the same gamma energy. The main apparatus is a multichannel pulse-height analyzer including a coincidence circuit. The principle of the method, the synoptic scheme, the electronic device, the type of sources, and the precautions to be taken or the corrections to take into account are reported. The results obtained in solving the three following problems are discussed as examples of applications of the method: analysis of {sup 241}Am in alpha-gamma sources containing {sup 238}Pu; analysis of {sup 237}Np in beta-gamma sources containing {sup 239}Pu; and analysis of {sup 106}Ru-{sup 106}Rh in beta-gamma sources containing {sup 95}Zr-{sup 95}Nb. (authors) [French] Dans ce. rapport, on presente une methode d'analyse spectrographique qualitative et quantitative de sources radioactives contenant deux emetteurs alpha-gamma de meme energie alpha et deux emetteurs beta-gamma de meme energie gamma. L'organe principal est un analyseur d'amplitude a 400 canaux comprenant un circuit de coincidence. On decrit le principe de la methode, le schema synoptique, l'appareillage, le type des sources, les precautions a prendre ou les corrections a faire. On discute les resultats obtenus dans la solution des trois problemes suivants traites a titre d'application de la methode: 1. analyse d'americium 241 en presence de plutonium 238; 2. analyse de neptunium 237 en presence de plutonium 239; 3. analyse de ruthenium 106-rhodium 106 en presence de zirconium 95-niobium 95. (auteurs)

The energy calibration and precision of a gamma spectrometry unit - Method using the electron annihilation energy as the only standard

International Nuclear Information System (INIS)

Hoclet, Michel

1971-06-01

Spectrometry using Ge(Li) detectors is discussed. The excellent resolution of this type of detector, the mathematical analysis of the spectral lines of the pulses, and the reproducibility of the spectrometer enable highly accurate measurements of the abscises (some 10 -5 ) corresponding to the peaks. A method using the annihilation energy of the electron as the only standard was developed. The method is applied to the measurement of the gamma ray energies of the radioelements: 22 Na, 24 Na, 56 Mn, 56 Co, 59 Fe, 72 Ga, 88 Y, 122 Sb, 124 Sb and 137 Cs. (author) [fr

134Cs emission probabilities determination by gamma spectrometry

Science.gov (United States)

de Almeida, M. C. M.; Poledna, R.; Delgado, J. U.; Silva, R. L.; Araujo, M. T. F.; da Silva, C. J.

2018-03-01

The National Laboratory for Ionizing Radiation Metrology (LNMRI/IRD/CNEN) of Rio de Janeiro performed primary and secondary standardization of different radionuclides reaching satisfactory uncertainties. A solution of 134Cs radionuclide was purchased from commercial supplier to emission probabilities determination of some of its energies. 134Cs is a beta gamma emitter with 754 days of half-life. This radionuclide is used as standard in environmental, water and food control. It is also important to germanium detector calibration. The gamma emission probabilities (Pγ) were determined mainly for some energies of the 134Cs by efficiency curve method and the Pγ absolute uncertainties obtained were below 1% (k=1).

Iodine 129 measurements by gamma spectrometry in biological samples. Results in seaweeds (Fucus serratus et laminaria digitata)

International Nuclear Information System (INIS)

Maro, D.; Hebert, D.; Gandon, R.; Solier, L.

1999-01-01

A iodine selective radiochemistry method was developed to measure 129 I(period 1,57 x 10 10 7 years) by gamma spectrometry in biological samples. This method avoids using neutron activation analysis or accelerator mass spectrometry. The method is based on iodine extraction from samples in order to obtain an aqueous matrix with no attenuation agent except 127 I(stable isotope). The parallel determination of 127 I allows to correct 129 I measurements for self attenuation and also monitor seasonal changes in iodine metabolism in biological species. Measurements were performed in two seaweed species (Fucus serratus and Laminaria digitata) samples in the area of La Hague reprocessing plant discharge between January and February 1997). Samples from stations close to the point of release (Goury and Herquemoulin), showed 129 I activities around 60 Bq kg -1 dry weight in Fucus serratus and around 300 Bq kg -1 dry weight in Laminaria digitata. 300 km away from the realize point, 129 I activities were 10 Bq kg -1 dry weight in Fucus serratus and 171 Bq kg -1 dry weight in Laminaria digitata. 127 I concentrations were between 547 and 1,232 mg kg -1 dry weight in Fucus serratus and between 6,624 and 14,296 mg kg -1 dry weight in Laminaria digitata. (authors)

Drill-Core Scanning for Radioelements by Gamma-Ray Spectrometry

DEFF Research Database (Denmark)

Løvborg, Leif; Wollenberg, H.; Rose-Hansen, J.

1972-01-01

A system has been developed for the continuous and stepwise scanning of rock drill cores for gamma-ray spectrometric determinations of uranium, thorium, and potassium. The apparatus accomodates 3- to 4-cm-diameter core as it passes two opposing 2-inch diameter by 3-inch- thick NaI(Tl) detectors, ......, disclosing detailed variations of U and Th. Contents of U and Th determined by scanning of drill core were consistent with the gross gamma-ray counting rates measured in the boreholes. ©1972 Society of Exploration Geophysicists......A system has been developed for the continuous and stepwise scanning of rock drill cores for gamma-ray spectrometric determinations of uranium, thorium, and potassium. The apparatus accomodates 3- to 4-cm-diameter core as it passes two opposing 2-inch diameter by 3-inch- thick NaI(Tl) detectors...

The application of computer technique in routine neutron activation analysis using high resolution gamma ray spectrometry

International Nuclear Information System (INIS)

Szopa, Z.; Plejewska, M.; Staszelis, J.

1982-01-01

A full system of four computer programs for routine - qualitative and quantitative - neutron activation analysis (NAA) using high resolution gamma ray-spectrometry had been elaborated. The structure and possibilities of the ''data flow'' programs i.e. programs DIDPDP and DIDCDC, dedicated for fast and reliable ''off line'' data transfer between the buffer memory of the spectrometric line (9-track magnetic tape) and the fast access memory (disc) of the used computers PDP-11/45 and CYBER-73 had been presented. The structure and organization of the ''data processing'' programs i.e. programs SAWAPS and MAZYG had been presented as well. The utility and reliability of these programs in the case of the large-scale, routine NAA, exampled by analysis of filters with air polutants, had been tested and discussed. Programs are written mainly in FORTRAN. (author)

The metrological activity determination of {sup 238} U and {sup 230} Th by gamma spectrometry to industrial fuel-cycle application

Energy Technology Data Exchange (ETDEWEB)

Almeida M, M.C. de; Delgado, J.U.; Poledna, R. [Instituto de Radioprotecao e Dosimetria- IRD/SEMRA, CNEN, Av. Salvador Allende s/n, Recreio, CEP 22780-160, Rio de Janeiro (Brazil)]. e-mail: marcandida@yahoo.com.br

2006-07-01

This work describes the difficulty for determining the activity of {sup 238} U and {sup 230} Th using gamma spectrometry due to the low gamma-ray emission probabilities of 92 and 67 keV, and, mainly, the associated high uncertainties about 13 and 11%, respectively. {sup 230} Th is a {sup 238} U daughter and it is product from uranium mills and refineries. {sup 230} Th decays to {sup 226} Ra and this decay has to be measured because these radionuclides are not in secular equilibrium with their daughter products, besides the gamma-energies have high uncertainties in the emission probabilities. These radionuclides, mostly {sup 238} U, are important in the nuclear fuel-cycle, since the mining of uranium ore, where the nominal isotopic content of natural uranium is 99.27% of {sup 238} U, until the irradiated fuel reprocessing, where this isotope, a fertile material, is recovered to be used again. The uranium and thorium are considered safeguarded nuclear materials and the metrology tries to calibrate and standardize these materials to improve the activity determination techniques applied in different fuel-cycle scopes. The essential characteristics of the safeguarded materials are low gamma energies (less than 100 keV) and emission probabilities but with high uncertainties. In this way, the metrology can contribute to homeland security defense against illicit nuclear trafficking with the identification and quantification of the safeguarded radionuclides such as uranium and thorium, using specific gamma window energy and high resolution planar or coaxial germanium detector. The efficiency curve is obtained from the reference source spectrum considering the photopeak areas corresponding the standard activities. This curve depends on radiation energy, sample geometry, photon attenuation (sample absorption and material absorption between sample-detector), dead time and sample-detector position. The metrological activity determinations of {sup 238} U solid sources, and of

40 K, 137 Cs and 232 Th activities in Brazilian milk samples measured by gamma ray spectrometry

International Nuclear Information System (INIS)

Melquiades, Fabio L.; Appoloni, Carlos R.

2000-01-01

This work deals with the measurement of radioactive activities in powdered milk, with high resolution gamma-ray spectrometry, using a HPGe detector coupled to a standard electronic nuclear chain and a multichannel card of 8192 channels. Preliminary measurements were accomplished to define the kind of the system shield, the geometry of the sample recipient, the size of the sampling and the self absorption correction. It was possible to measure the radionuclides 40 K, 137 Cs and 208 Tl, whose activities were calculated according to the International Atomic Energy Agency norms. The detector efficiency was measured employing calibrated samples, prepared with IAEA certificate standards mixed with powdered milk. Tukey's average comparison test was used to check the repeatability of the measurements and the absence of significant systematic deviation. (author)

Study pf apatite accurrence from Gaviao and Serra de Jacabina gold deposit by scintillometry and gamma spectrometry

International Nuclear Information System (INIS)

Barreto, P.T.

1974-01-01

This work presents the results of radiogeologic reconnaissance in the Cenozoic, Mesozoic and Pre-Cambrian formations, localized between Salvador and Miguel Calmon, and of the radiogeologic detail study from areas of the radioactive anomalies: Gaviao in the Riacho do Lacuipe and Canavieira Mine, in the Jacobina, Bahia States Scintilometry and gamma spectrometry results make possible to conclude by the association, in the Gaviao's apatite mineralization with throrium and the gold of the Serra de Corrego's conglamerate with uranium, make possible in the both case, orient the Search and the mining by scintilometry. The petrographic study and the radiactivity elements dispersion, suggest a sedimentary primary origin to the regional metamorphic rocks. In the Canavieiras mine was evident the stratigraphic control of the gold, associated to uranium and pirite in the conglomerates. (C.D.G.) [pt

Study of gamma radiation between 0.1 and 1.0 MeV in the earth's atmosphere; Etude du rayonnement gamma entre 0,1 et 1 Mev dans l'atmosphere terrestre

Energy Technology Data Exchange (ETDEWEB)

Boclet, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-01-01

The present work is devoted to some of the particular problems arising in the detection and localisation of sources of gamma radiation situated outside the earth's atmosphere. These weak sources can only be detected and localized if care is taken to eliminate gamma and particle radiations coming from other sources in the earth's atmosphere and in space. In order to separate the various sources of background noise, generally much stronger than the radiation under study, use is made of a directional detector whose characteristics are determined as described in the first part of the following report. The closest diffuse source considered is that constituted by the earth's atmosphere. Its detailed study will make it possible both to eliminate its effect when sources outside the earth are to be measured, and to predict the amount of secondary gamma radiation emitted by the same process in other celestial bodies, the moon in particular. This work considered in the 2. and 3. parts of the report. (author) [French] La presente etude est consacree a certains des problemes particuliers poses par la detection et la localisation des sources de rayonnement gamma situees hors de l'atmosphere terrestre. Ces sources faibles ne peuvent etre detectees et localisees que si l'on se protege des rayonnements gamma et particulaires provenant d'autres sources situees dans l'atmosphere terrestre et dans l'espace. Pour separer ces divers composants parasites, en general beaucoup plus intenses que le rayonnement a etudier, nous emploierons un detecteur directif dont nous determinons les caracteristiques dans la premiere partie de l'expose qui suit. La source diffuse la plus proche que nous considerons comme parasite est constituee par l'atmosphere terrestre. Son etude detaillee nous permettra d'une part de nous en proteger lorsque nous voudrons etudier les sources {gamma} extra-terrestres, d'autre part de prevoir le rayonnement gamma secondaire emis par le meme processus pour les autres corps

Estimation of natural potassium concentration in Romanian males by in vivo gamma-ray spectrometry measurements

International Nuclear Information System (INIS)

Mirela Angela Saizu

2012-01-01

At the Whole Body Monitoring Laboratory, from IFIN-HH, Bucharest, Romania, there were performed in vivo gamma-ray spectrometry measurements on 108 Romanian males in order to evaluate the mineral natural potassium content in human body, as total value and concentration. The measurements were performed with a shadow shield whole body counter, tilted chair geometry, based on a shielded NaI(Tl) scintillation detector of 12.5 cm (diameter) x 10 cm (height) crystal size. The results revealed a calculated value of the mean total body potassium (TBK) of 135.03 ± 2.94 g and a value of 1.9 ± 0.022 g of potassium/kg of body weight for the mean body potassium concentration, for the measured males. These values are similar with the values declared for the Reference Man, in ICRP23. Correlations between total body potassium, potassium concentration and age, weight and Body Build Index were investigated and peculiar conclusions were resulted. (author)

Solid state scintillators for gamma spectrometry. Studio di scintillatori a stato solido per spettrometria gamma

Energy Technology Data Exchange (ETDEWEB)

La Mela, G; Torrisi, M [Istituto Nazionale di Fisica Nucleare, Catania (Italy)

1991-01-01

Using different scintillator crystals, measurements of energy resolution and detection efficiency have been performed to detect gamma rays of energy ranging between 500 en 1550 KeV. This investigation is devoted to characterize the best systems to detect photons coming from positron annihilation processes, such as a PET apparatus where the medical image is the final aim of the investigation, and gamma emission from radioisotopes of biomedical interest.

Gamma spectrometry of EFTTRA T2BIS R280.2. Gamma scan wires 6 through 10

International Nuclear Information System (INIS)

Dassel, G.; Buurveld, H.A.; Plakman, J.C.

1996-11-01

In the frame work of the EFTTRA programme on recycling of actinides and fission products, five gamma scan wires which were included in the experiment R280.2 T2bis have been examined by gamma scanning. The results of the measurements have been described in this report. (orig.)

Instruments used to measure or check {alpha}, {beta}, {gamma} activity and neutron emission in the course of processing ore or irradiated fuel; Appareils de mesure ou de controle {alpha}, {beta}, {gamma}, n, des circuits des usines de traitement du minerai ou du combustible irradie

Energy Technology Data Exchange (ETDEWEB)

Blanc, A; Brunet, M; Kermagoret, M; Labeyrie, J; Roux, G; Vasseur, J; Weil, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1959-07-01

plutonium et des produits de fission dans les differents circuits, et sur la radioactivite des effluents rejetes par l'usine dans les cours d'eau. Le controle des operations de fixation et d'elution de l'uranium est effectue automatiquement par un appareil qui preleve, evapore et mesure l'activite {alpha} de 5 cm{sup 3} de solution toutes les 10 ou 20 minutes. Les teneurs en plutonium sont mesurees: - en presence de fortes activites {beta} {gamma} par des detecteurs {alpha} a cylindres tournants; - en presence de faibles activites {beta} {gamma} par des detecteurs {alpha} examinant une surface liquide a niveau constant; - par des chambres a fission peu sensibles aux {gamma}. Les teneurs en produits de fission sont mesurees par des chambres, compteurs, ou scintillateurs, selon l'importance de l'activite {gamma}. Enfin, le controle de l'activite des effluents a rejeter dans les cours d'eau est realise par un appareil a scintillation mesurant l'activite {alpha} d'une part et, d'autre part l'activite {alpha} {gamma} des residus d'un echantillon de 100 cm{sup 3} preleve et evapore en 20 minutes. (auteur)

Stabilization of spectra provided by a gamma-ray spectrometer. Application to the construction of a stabilizer; Stabilisation des spectres fournis par un spectrometre a rayons gamma. Application a la realisation d'un stabilisateur

Energy Technology Data Exchange (ETDEWEB)

Detourne, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-06-15

This research is concerned with the stabilization of spectra provided by a gamma-ray spectrometer. It is required to hold the calibration straight line of the spectrometer in a position which is fixed initially to better than 5x10{sup -5} channel. A prototype numerical stabilizer has been constructed : the SPECTROSTAB; it is made up of two independent control loops; one of these makes the spectrometer gain depend on the derivatives of a reference peak at high energies; the other makes the origin of the energy scale depend on the derivatives of a second reference peak at low energies A theoretical study of the behaviour of a control loop shows that a direct action stabilizer gives the most accurate stabilization; the loss in resolving power on the theoretical peaks of the spectra attains about 1 % with a scintillation detector, and 10 % with a semi-conductor detector. Various tests show that the expected results are obtained and that the displacement of the spectral peaks produced by the derivatives are hidden by errors in the calculation of the peak abscissae. (author) [French] Cette etude a pour objet la stabilisation des spectres fournis par un spectrometre a rayons gamma. On veut maintenir la droite d'etalonnage du spectrometre dans une position fixee initialement a mieux de 6.10{sup -5} canal pres. On realise un prototype de stabilisateur numerique, le SPECTROSTAB; il comprend deux boucles d'asservissement independantes; l'une d'elles asservit le gain du spectrometre aux derives d'un pic de reference aux hautes energies; l'autre asservit l'origine de l'echelle des energies aux derives d'un second pic de reference aux basses energies. Une etude theorique du comportement d'une boucle d'asservissement montre qu'un stabilisateur a action directe permet la stabilisation la plus precise; la perte en resolution sur les pics theoriques des spectres atteint environ 1 % avec un detecteur a scintillateur et 10 % avec un detecteur a semi-conducteur. Divers essais montrent

Nondestructive and quantitative characterization of TRU and LLW mixed-waste using active and passive gamma-ray spectrometry and computed tomography

Energy Technology Data Exchange (ETDEWEB)

Camp, D.C.; Martz, H.E.

1991-11-12

The technology being proposed by LLNL is an Active and Passive Computed Tomography (A P CT) Drum Scanner for contact-handled (CH) wastes. It combines the advantages offered by two well-developed nondestructive assay technologies: gamma-ray spectrometry and computed tomography (CT). Coupled together, these two technologies offer to nondestructively and quantitatively characterize mixed- wastes forms. Gamma-ray spectroscopy uses one or more external radiation detectors to passively and nondestructively measure the energy spectrum emitted from a closed container. From the resulting spectrum one can identify most radioactivities detected, be they transuranic isotopes, mixed-fission products, activation products or environmental radioactivities. Spectral libraries exist at LLNL for all four. Active (A) or transmission CT is a well-developed, nondestructive medical and industrial technique that uses an external-radiation beam to map regions of varying attenuation within a container. Passive (P) or emission CT is a technique mainly developed for medical application, e.g., single-photon emission CT. Nondestructive industrial uses of PCT are under development and just coming into use. This report discuses work on the A P CT Drum Scanner at LLNL.

Determination of the Concentration of Radioactive Nuclides of Surface Soils of some Hadhramout's Valleys in Yemen Using Gamma-Ray Spectrometry

International Nuclear Information System (INIS)

Bazohair, A. O.; Bayashoot, A. K.; AL-Shamy, A. A.

2004-01-01

In this research five surface soil samples have been taken from some Hadhramout's valleys in Yemen (Khrid , Arf , Huwayrah , Buwaish, Khirba ) in the years from (1999) to (2002) and analyzed using gamma-ray spectrometry. The spectra of samples were measured using multichannel analyzer (MCA) that was connected with measurement system for this purpose.A high purity germanium(Hp Ge) detector with resolution of (2.11 keV) at gamma-line(1332 keV) of radioactive source(Co-60) used for detecting ( U 238 , Th 232 , K 40 , Cs 137 ) in the samples. The results showed that the average concentration of radioactive nuclides in the samples of uranium ranged from(37.56 Bq/Kg) to(46.58 Bq/Kg) and for thorium ranged from(37.93 Bq/Kg) to(47.28 Bq/Kg) and for potassium ranged from(347.57 Bq/Kg) to(850.10 Bq/Kg) and for cesium ranged from(6.94 Bq/Kg) to(15.86 Bq/Kg) and the measured precision of samples ranged from(4.71%) to (9.23%). (authors)

On the honeybee resistance to gamma radiation; Sur la resistance au rayonnement gamma de l'abeille ouvriere

Energy Technology Data Exchange (ETDEWEB)

Courtois, G.; Lecomte, J. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Section des Applications des Radioelements, Centre d' Etudes Nucleaires, Saclay, Station de Recherches Apicoles, Bures-sur-Yvette (France)

1960-07-01

The honeybee, when irradiated by gamma radiations from a cobalt-60 source can stand a 18000 r dose without any apparent harm. Noticeable harm is observed for 90000 r. while immediate death of 100% of the individuals is obtained with a 200000 r dose. The physiological condition of the honeybee plays an important role in its resistance to gamma radiation. Reprint of a paper published in Annales de l'abeille, IV, 1959, p. 285-290 [French] L'Abeille butineuse irradiee par le rayonnement gamma issu d'une source de Cobalt 60 supporte sans dommages apparents une dose de 18000 r. Des dommages tres appreciables sont observes pour 90000 r. Une dose de 200000 r entraine la mort immediate de 100% des individus. L'etat physiologique de l'Abeille joue un role important dans la resistance au rayonnement gamma. Reproduction d'un article publie dans Annales de l'abeille, IV, 1959, p. 285-290.

A gamma-gamma coincidence/anticoincidence spectrometer for low-level cosmogenic (22)Na/(7)Be activity ratio measurement.

Science.gov (United States)

Zhang, Weihua; Ungar, Kurt; Stukel, Matthew; Mekarski, Pawel

2014-04-01

In this study, a digital gamma-gamma coincidence/anticoincidence spectrometer was developed and examined for low-level cosmogenic (22)Na and (7)Be in air-filter sample monitoring. The spectrometer consists of two bismuth germanate scintillators (BGO) and an XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The spectrometer design allows a more selective measurement of (22)Na with a significant background reduction by gamma-gamma coincidence events processing. Hence, the system provides a more sensitive way to quantify trace amounts of (22)Na than normal high resolution gamma spectrometry providing a critical limit of 3 mBq within a 20 h count. The use of a list-mode data acquisition technique enabled simultaneous determination of (22)Na and (7)Be activity concentrations using a single measurement by coincidence and anticoincidence mode respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Simultaneous determination of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry INa(Ti), in solid samples

International Nuclear Information System (INIS)

Salvador, S.; Navarro, T.; Alvarez, A.

1991-01-01

A method has been developed to determine activities of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry. The measurement system has been calibrated using standards specially prepared at the laboratory. It is necessary to assume secular equilibrium in the samples, between Ra-226 and Th-232 and its daughters nuclides, and between U-238 and its immediate daughter Th-234, as the photo peaks measured are those of the daughters. The results obtained indicate that this method can of ter replace the radiochemical techniques used to measure activities in this type of sample. The method has been successfully used to determine these natural isotopes in samples from uranium mills. (Author) 9 refs

Gamma-emissions of some meteorites and terrestrial rocks. Evaluation of lunar soil radioactivity

International Nuclear Information System (INIS)

Nordemann, D.

1966-01-01

The gamma-emissions of some terrestrial rocks and of the following meteorites: Bogou, Eagle-Station, Granes, and Dosso were studied by quantitative low background gamma spectrometry. These measurements and their interpretation lead to the evaluation of the possible gamma-emissions of several models of lunar soils. (author) [fr

Virtual Gamma Ray Radiation Sources through Neutron Radiative Capture

Energy Technology Data Exchange (ETDEWEB)

Scott Wilde, Raymond Keegan

2008-07-01

The countrate response of a gamma spectrometry system from a neutron radiation source behind a plane of moderating material doped with a nuclide of a large radiative neutron capture cross-section exhibits a countrate response analogous to a gamma radiation source at the same position from the detector. Using a planar, surface area of the neutron moderating material exposed to the neutron radiation produces a larger area under the prompt gamma ray peak in the detector than a smaller area of dimensions relative to the active volume of the gamma detection system.

Measurements of radionuclide in Par Pond sediments with an underwater HPGe detector

International Nuclear Information System (INIS)

Winn, W.G.

1993-01-01

Savannah River Site (SRS) effluent gamma emitting radionuclides in Par Pond sediment were examined in situ with an underwater HPGe detector prior to and following a 19 ft drawdown of the pond in 1991 to address dam repairs. These measurements provide a map of the 137 Cs concentrations of the pond sediment, indicating that 9.4 ± 1.5 Ci is exposed by the drawdown and that 46.6 ± 7.2 Ci is the entire pond inventory. The highest individual 137 Cs concentration was 25 μCi/m 2 for the exposed sediment and 50 μCi/m 2 for the entire pond. The results are consistent with parallel studies conducted by SREL, as well as historical data. Aside from 137 Cs, the only other SRS-produced isotope observed was 60 Co, with activity of only about 1% of that for 137 Cs. This observation was also confirmed in grab samples of pond sediment and vegetation, which were returned to the laboratory for ultra-low-level gamma spectrometry analysis. A special effort was required to calibrate the underwater HPGe detector, where both measurements and calculational models were used. The effects of sediment depth profiles for density and 137 Cs concentration were addressed in the calibration. Calibration factors for sediment surface concentrations (μCi/m 2 /cpm) and sediment mass concentrations (pCi/kg/cpm) were obtained. In general, the μCi/m 2 /cpm factor is recommended, as the pCi/kg/cpm factor depends on the depth location of the sediment of interest. However, a pCi/kg/cpm factor, which is dependent on the depth within the sediment is presented to address dose calculations that require it

Construction and Operation of a Commercial Gamma-Ray Package-Sterilizing Plant; Construction et fonctionnement d'une installation industrielle pour la sterilisation d'articles sous emballage par les rayons gamma; Razrabotka i ehkspluatatsiya sbornoj ustanovki gamma-izlucheniya promyshlennogo tipa dlya sterilizatsii meditsinskikh materialov; Construccion y funcionamiento de una instalacion industrial para la esterilizacion gamma de articulos medicos empaquetados

Energy Technology Data Exchange (ETDEWEB)

Crawford, C. G. [Johnson' s Ethical Plastics Ltd., Slough (United Kingdom)

1963-11-15

The purpose of the paper is to describe the Co{sup 60} sterilizing plant now being operated commercially by Johnson's Ethical Plastics Limited, at Slough, England. This is a continuous process plant with a source of 72000 c and completely automatic operation. Based on experience gained by U.K.A.E.A. in their Package Irradiation Plant at Wantage, the present plant was designed specifically for sterilization of disposable plastic syringes and other medical products of similar bulk density. The plant has been in operation since November 1962. A description is given of the main features of its construction, including personnel safety devices, and method of loading the source rods. Operating experience is described including dosimetry, integration of the plant into a commercial undertaking as a production process, and bacteriological results. A short discussion on the economics of sterilizing by gamma radiation is given and an assessment of possible future applications of a plant of this type. (author) [French] Le memoire est consacre a la description de l'installation de sterilisation au cobalt-60, actuellement exploitee industriellement par la Johnson Ethical Plastics Ltd., a Slough (Angleterre). Cette installation, equipee d'une source de 72 000 c, fonctionne en continu et toutes les operations y sont automatiques. Fondee sur l'experience acquise par l'Autorite de l'energie atomique du Royaume-Uni dans son installation d'irradiation d'articles sous emballage, de Wantage, l'installation decrite est specialement destinee a la sterilisation de seringues en matieres plastiques et d'autres instruments medicaux non recuperables de densite apparente analogue. L'installation est en service depuis novembre 1962. Le memoire decrit ses principales caracteristiques, y compris les appareils de protection du personnel et les dispositifs de chargement des barreaux utilises comme sources. L'auteur fournit des donnees d'ordre pratique, notamment sur la dosimetrie, l'integration de l

Determination of the detection limit and decision threshold for ionizing radiation measurements. Part 3: Fundamentals and application to counting measurements by high resolution gamma spectrometry, without the influence of sample treatment

International Nuclear Information System (INIS)

2000-01-01

This part of ISO 11929 addresses the field of ionizing radiation measurements in which events (in particular pulses) are counted by high resolution gamma spectrometry registrating a pulse-heights distribution (acquisition of a multichannel spectrum), for example on samples. It considers exclusively the random character of radioactive decay and of pulse counting and ignores all other influences (e.g. arising from sample treatment, weighing, enrichment or the instability of the test setup). It assumes that the distance of neighbouring peaks of gamma lines is not smaller than four times the full width half maximum (FWHM) of gamma line and that the background near to gamma line is nearly a straight line. Otherwise ISO 11929-1 or ISO 11929-2 should be used. ISO 11929 consists of the following parts, under the general title Determination of the detection limit and decision threshold for ionizing radiation measurements: Part 1: Fundamentals and application to counting measurements without the influence of sample treatment; Part 2: Fundamentals and application to counting measurements with the influence of sample treatment; Part 3: Fundamentals and application to counting measurements by high resolution gamma spectrometry, without the influence of sample treatment; Part 4: Fundamentals and application to measurements by use of linear scale analogue ratemeters, without the influence of sample treatment. This part of ISO 11929 was prepared in parallel with other International Standards prepared by WG2 (now WG 17): ISO 11932:1996, Activity measurements of solid materials considered for recycling, re-use or disposal as nonradioactive waste, and ISO 11929-1, ISO 11929-2 and ISO 11929-4, and is, consequently, complementary to these documents

A simple gamma spectrometry method for evaluating the burnup of MTR-type HEU fuel elements

Energy Technology Data Exchange (ETDEWEB)

Makmal, T. [The Unit of Nuclear Engineering, Ben-Gurion University of The Negev, Beer-Sheva 84105 (Israel); Nuclear Physics and Engineering Division, Soreq Nuclear Research Center, Yavne 81800 (Israel); Aviv, O. [Radiation Safety Division, Soreq Nuclear Research Center, Yavne 81800 (Israel); Gilad, E., E-mail: gilade@bgu.ac.il [The Unit of Nuclear Engineering, Ben-Gurion University of The Negev, Beer-Sheva 84105 (Israel)

2016-10-21

A simple method for the evaluation of the burnup of a materials testing reactor (MTR) fuel element by gamma spectrometry is presented. The method was applied to a highly enriched uranium MTR nuclear fuel element that was irradiated in a 5 MW pool-type research reactor for a total period of 34 years. The experimental approach is based on in-situ measurements of the MTR fuel element in the reactor pool by a portable high-purity germanium detector located in a gamma cell. To corroborate the method, analytical calculations (based on the irradiation history of the fuel element) and computer simulations using a dedicated fuel cycle burnup code ORIGEN2 were performed. The burnup of the MTR fuel element was found to be 52.4±8.8%, which is in good agreement with the analytical calculations and the computer simulations. The method presented here is suitable for research reactors with either a regular or an irregular irradiation regime and for reactors with limited infrastructure and/or resources. In addition, its simplicity and the enhanced safety it confers may render this method suitable for IAEA inspectors in fuel element burnup assessments during on-site inspections. - Highlights: • Simple, inexpensive, safe and flexible experimental setup that can be quickly deployed. • Experimental results are thoroughly corroborated against ORIGEN2 burnup code. • Experimental uncertainty of 9% and 5% deviation between measurements and simulations. • Very high burnup MTR fuel element is examined, with 60% depletion of {sup 235}U. • Impact of highly irregular irradiation regime on burnup evaluation is studied.

Mapping the spatial distribution and activity of "2"2"6Ra at legacy sites through Machine Learning interpretation of gamma-ray spectrometry data

International Nuclear Information System (INIS)

Varley, Adam; Tyler, Andrew; Smith, Leslie; Dale, Paul; Davies, Mike

2016-01-01

Radium ("2"2"6Ra) contamination derived from military, industrial, and pharmaceutical products can be found at a number of historical sites across the world posing a risk to human health. The analysis of spectral data derived using gamma-ray spectrometry can offer a powerful tool to rapidly estimate and map the activity, depth, and lateral distribution of "2"2"6Ra contamination covering an extensive area. Subsequently, reliable risk assessments can be developed for individual sites in a fraction of the timeframe compared to traditional labour-intensive sampling techniques: for example soil coring. However, local heterogeneity of the natural background, statistical counting uncertainty, and non-linear source response are confounding problems associated with gamma-ray spectral analysis. This is particularly challenging, when attempting to deal with enhanced concentrations of a naturally occurring radionuclide such as "2"2"6Ra. As a result, conventional surveys tend to attribute the highest activities to the largest total signal received by a detector (Gross counts): an assumption that tends to neglect higher activities at depth. To overcome these limitations, a methodology was developed making use of Monte Carlo simulations, Principal Component Analysis and Machine Learning based algorithms to derive depth and activity estimates for "2"2"6Ra contamination. The approach was applied on spectra taken using two gamma-ray detectors (Lanthanum Bromide and Sodium Iodide), with the aim of identifying an optimised combination of detector and spectral processing routine. It was confirmed that, through a combination of Neural Networks and Lanthanum Bromide, the most accurate depth and activity estimates could be found. The advantage of the method was demonstrated by mapping depth and activity estimates at a case study site in Scotland. There the method identified significantly higher activity ( 0.4 m), that conventional gross counting algorithms failed to identify. It was

Computers in activation analysis and gamma-ray spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Carpenter, B. S.; D' Agostino, M. D.; Yule, H. P. [eds.

1979-01-01

Seventy-three papers are included under the following session headings: analytical and mathematical methods for data analysis; software systems for ..gamma..-ray and x-ray spectrometry; ..gamma..-ray spectra treatment, peak evaluation; least squares; IAEA intercomparison of methods for processing spectra; computer and calculator utilization in spectrometer systems; and applications in safeguards, fuel scanning, and environmental monitoring. Separate abstracts were prepared for 72 of those papers. (DLC)

Analytical applications of neutron capture gamma-rays

International Nuclear Information System (INIS)

Lindstrom, R.M.; Paul, R.L.; Anderson, D.L.; Paul, R.L.

1997-01-01

Field and industrial applications of neutron capture gamma-ray spectrometry with isotopic sources or neutron generators are economically important. Geochemical exploration in boreholes is done routinely with neutron probes. Coal and ores are assayed with analyzers adjacent to a conveyor belt in dozens of industrial facilities. The use of capture gamma rays for explosives detection has been described in the literature, both for scanning airline baggage and for characterizing obsolete munitions; a packaged system for the latter is available commercially. Generalizations are drawn from the history of the field, and predictions are made about the future usefulness of capture gamma rays. (author)

An improved in situ method for determining depth distributions of gamma-ray emitting radionuclides

International Nuclear Information System (INIS)

Benke, R.R.; Kearfott, K.J.

2001-01-01

In situ gamma-ray spectrometry determines the quantities of radionuclides in some medium with a portable detector. The main limitation of in situ gamma-ray spectrometry lies in determining the depth distribution of radionuclides. This limitation is addressed by developing an improved in situ method for determining the depth distributions of gamma-ray emitting radionuclides in large area sources. This paper implements a unique collimator design with conventional radiation detection equipment. Cylindrically symmetric collimators were fabricated to allow only those gamma-rays emitted from a selected range of polar angles (measured off the detector axis) to be detected. Positioned with its axis normal to surface of the media, each collimator enables the detection of gamma-rays emitted from a different range of polar angles and preferential depths. Previous in situ methods require a priori knowledge of the depth distribution shape. However, the absolute method presented in this paper determines the depth distribution as a histogram and does not rely on such assumptions. Other advantages over previous in situ methods are that this method only requires a single gamma-ray emission, provides more detailed depth information, and offers a superior ability for characterizing complex depth distributions. Collimated spectrometer measurements of buried area sources demonstrated the ability of the method to yield accurate depth information. Based on the results of actual measurements, this method increases the potential of in situ gamma-ray spectrometry as an independent characterization tool in situations with unknown radionuclide depth distributions

Mapping of radiation anomalies using UAV mini-airborne gamma-ray spectrometry.

Science.gov (United States)

Šálek, Ondřej; Matolín, Milan; Gryc, Lubomír

2018-02-01

Localization of size-limited gamma-ray anomalies plays a fundamental role in uranium prospecting and environmental studies. Possibilities of a newly developed mini-airborne gamma-ray spectrometric equipment were tested on a uranium anomaly near the village of Třebsko, Czech Republic. The measurement equipment was based on a scintillation gamma-ray spectrometer specially developed for unmanned aerial vehicles (UAV) mounted on powerful hexacopter. The gamma-ray spectrometer has two 103 cm 3 BGO scintillation detectors of relatively high sensitivity. The tested anomaly, which is 80 m by 40 m in size, was investigated by ground gamma-ray spectrometric measurement in a detail rectangular measurement grid. Average uranium concentration is 25 mg/kg eU attaining 700 mg/kg eU locally. The mini-airborne measurement across the anomaly was carried out on three 100 m long parallel profiles at eight flight altitudes from 5 to 40 m above the ground. The resulting 1 s 1024 channel gamma-ray spectra, recorded in counts per second (cps), were processed to concentration units of K, U and Th, while total count (TC) was reported in cps. Increased gamma ray intensity of the anomaly was indicated by mini-airborne measurement at all profiles and altitudes, including the highest altitude of 40 m, at which the recorded intensity is close to the natural radiation background. The reported instrument is able to record data with comparable quality as standard airborne survey, due to relative sensitive detector, lower flight altitude and relatively low flight speed of 1 m/s. The presented experiment brings new experience with using unmanned semi-autonomous aerial vehicles and the latest mini-airborne radiometric instrument. The experiment has demonstrated the instrument's ability to localize size-limited uranium anomalies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Digital approach to high rate gamma-ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Korolczuk, Stefan; Mianowski, Slawomir; Rzadkiewicz, Jacek; Sibczynski, Pawel; Swiderski, Lukasz; Szewinski, Jaroslaw; Zychor, Izabella [Narodowe Centrum Badan Jadrowych (NCBJ), 05-400 Otwock, (Poland)

2015-07-01

Basic concepts and preliminary results of creating high rate digital spectrometry system using efficient ADCs and latest FPGA are presented as well as a comparison with commercially available devices. The possibility to use such systems, coupled to scintillators, in plasma experiments is discussed. (authors)

{sup 129}I determination by direct Ge gamma-X spectrometry and its application to the concentration variation in two seaweed species

Energy Technology Data Exchange (ETDEWEB)

Barker, E.; Bouisset, P. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Environmental Radioactivity Measurement Lab., 91 - Orsay (France); Masson, M.; Germain, P. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Octeville-Cherbourg Radioecology Lab., 50 - Octeville -Cherbourg (France); Siclet, F. [Electricite de France (EDF), 78 - Chatou (France)

2004-07-01

The quantification of radionuclides by direct Ge gamma-X spectrometry with energy below 100 keV requires the elementary composition knowledge of the sample or the development of a device for determining the mass attenuation coefficients. This is especially true for {sup 129}I which is characterised by a 29.7 keV X-ray and 39.6 keV gamma ray. An experimental equipment has been developed in order to obtain this mass attenuation coefficient as a function of the energy. The elementary composition of a sample could change according to the biological phase of the organism and the sample preparation. {sup 129}I concentrations have been measured in samples of seaweed (Fucus serratus and Laminaria digitata) collected monthly during one year nearby La Hague reprocessing plant. Its quantification in different parts of these seaweeds was also performed in order to study the activity distribution. This paper will present measurement methodology used for {sup 129}I determination and its concentration variations during one-year period and the organo-tropism of {sup 129}I in the two seaweeds. (author)

Levelling Airborne and Ground Gamma-Ray Spectrometric Data to Assist Uranium Exploration

Energy Technology Data Exchange (ETDEWEB)

Matolin, M., E-mail: matolin@natur.cuni.cz [Charles University, Prague (Czech Republic); Minty, B. [Geoscience Australia, Canberra (Australia)

2014-05-15

Geophysical methods can be used for mapping in both 2 and 3 dimensions, as well as the direct detection of ore bodies. The gamma-ray spectrometric method is an efficient method for the regional assessment of uranium potential and the detection of surface mineralization. However, the full potential of the method can only be realized when the data are adequately standardized. Examples of this standardization at both regional and local scales are dealt in this paper. At a regional scale, it is shown how the levelling of airborne gamma-ray spectrometry data over Australia increases the value of the resulting data, and on a local scale a geometrical correction for ground gamma-ray spectrometry in shallow holes that improves the accuracy of measurements is introduced. (author)

Mapping the spatial distribution and activity of {sup 226}Ra at legacy sites through Machine Learning interpretation of gamma-ray spectrometry data

Energy Technology Data Exchange (ETDEWEB)

Varley, Adam, E-mail: a.l.varley@stir.ac.uk [Department of Biological and Environmental Sciences, University of Stirling, Stirling FK9 4LA (United Kingdom); Tyler, Andrew [Department of Biological and Environmental Sciences, University of Stirling, Stirling FK9 4LA (United Kingdom); Smith, Leslie [Department of Computing Science and Mathematics, University of Stirling, Stirling FK9 4LA (United Kingdom); Dale, Paul [Scottish Environmental Protection Agency, Radioactive Substances, Strathallan House, Castle Business Park, Stirling FK9 4TZ (United Kingdom); Davies, Mike [Nuvia Limited, The Library, Eight Street, Harwell Oxford, Didcot, Oxfordshire OX11 0RL (United Kingdom)

2016-03-01

Radium ({sup 226}Ra) contamination derived from military, industrial, and pharmaceutical products can be found at a number of historical sites across the world posing a risk to human health. The analysis of spectral data derived using gamma-ray spectrometry can offer a powerful tool to rapidly estimate and map the activity, depth, and lateral distribution of {sup 226}Ra contamination covering an extensive area. Subsequently, reliable risk assessments can be developed for individual sites in a fraction of the timeframe compared to traditional labour-intensive sampling techniques: for example soil coring. However, local heterogeneity of the natural background, statistical counting uncertainty, and non-linear source response are confounding problems associated with gamma-ray spectral analysis. This is particularly challenging, when attempting to deal with enhanced concentrations of a naturally occurring radionuclide such as {sup 226}Ra. As a result, conventional surveys tend to attribute the highest activities to the largest total signal received by a detector (Gross counts): an assumption that tends to neglect higher activities at depth. To overcome these limitations, a methodology was developed making use of Monte Carlo simulations, Principal Component Analysis and Machine Learning based algorithms to derive depth and activity estimates for {sup 226}Ra contamination. The approach was applied on spectra taken using two gamma-ray detectors (Lanthanum Bromide and Sodium Iodide), with the aim of identifying an optimised combination of detector and spectral processing routine. It was confirmed that, through a combination of Neural Networks and Lanthanum Bromide, the most accurate depth and activity estimates could be found. The advantage of the method was demonstrated by mapping depth and activity estimates at a case study site in Scotland. There the method identified significantly higher activity (< 3 Bq g{sup −1}) occurring at depth (> 0.4 m), that conventional gross

Applicability study of using in-situ gamma-ray spectrometry technique for 137Cs and 210Pbex inventories measurement in grassland environments

International Nuclear Information System (INIS)

Li Junjie; Li Yong; Wang Yanglin; Wu Jiansheng

2010-01-01

In-situ measurement of fallout radionuclides 137 Cs and 210 Pb ex has the potential to assess soil erosion and sedimentation rapidly. In this study, inventories of 137 Cs and 210 Pb ex in the soil of Inner Mongolia grassland were measured using an In-situ Object Counting System (ISOCS). The results from the field study indicate that in-situ gamma-ray spectrometry has the following advantages over traditional laboratory measurements: no extra time is required for sample collection, no reference inventories are required, more economic, prompt availability of the results, the ability to average radionuclide inventory over a large area, and high precision.

Borehole Logging for Uranium by Gamma-Ray Spectrometry

DEFF Research Database (Denmark)

Løvborg, Leif; Nyegaard, P.; Christiansen, E. M.

1980-01-01

The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium-iodide, and the photo......The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium...... of the spectrometer system were determined by calculating the average number of U and thorium (Th) counts per meter of borehole and comparing these with the U-Th concentrations in 1-m sections of analyzed drill core. The sensitivity and the background count rate in the uranium window varied appreciably from one hole...

Study of operational systems of gamma spectrometry systems

International Nuclear Information System (INIS)

Melo, M.C. de.

1985-07-01

The application of gamma spectrometers is tantamount to the perfect knowledge of their operational characteristics. Thus a study of the most significant characteristics (stability, linearity of response, energy resolution and peak efficiency) was carried out with an NaI(T1) and an (HP)Ge systems. Gamma standards with an energy range of 60 to 1300 KeV were used. Simple numerical methods were applied to the data, and the Behaviour of each system, with regard to the aforementioned characteristics, was observed for several operation voltages. It was evident the superiority of the (HP)Ge system in stability, linearity and resolution, whereas the NaI(T1) system showed a greater efficiency. The results obtained for each system were consistent with the ones found elsewhere, so that it may be concluded that both are working properly, and that the methodology proposed herein is appropriate for the test of such equipments [pt

Relative Biological Effectiveness of 14-MeV Fast Neutrons to Co{sup 60} Gamma-Rays in Einkorn Wheat; Efficacite Biologique Relative des Neutrons Rapides de 14 MeV par Rapport aux Rayons Gamma de {sup 60}Co sur l'Engrain; Otnositel'naya biologicheskaya ehffektivnost' bystrykh nejtronov s ehnergiej 14 MeV i gamma-luchej CO{sup 60} pri ikh dejstvii na pshenitsu odnozernyanku; EBR de los Neutrones Rapidos de 14 MeV y de los Rayos Gamma del {sup 60}Co en el Trigo Escanda Menor

Energy Technology Data Exchange (ETDEWEB)

Fujii, T. [National Institute of Genetics, Misima (Japan)

1964-05-15

somatic mutation. (author) [French] L' auteur a etudie l'EBR des neutrons de 14 MeV par rapport aux rayons gamma de {sup 60}Co en appliquant a l'engrain la methode des loci specifiques. Il a utilise pour cette etude des semences Fi resultant du croisement entre l'espece originale et un mutant chlorina (le mutant chlorina e ta it le produit d'une mutation recessive induite par les rayons X ; depuis le stade de plantule jusqu'a sa maturite, le m utant a conserve une couleur vert c la ir uniforme ainsi qu'un taux de survie et une fe rtilite relativement eleves). Les plantes Fi avaient une couleur verte et une croissance normales. Des semences dormantes de F{sub 1} ont e te irradiees avec 0,5 , 1,0 et 1,4 krad de neutrons rapides et avec 4,3 , 8,6 et 12,9 krad de rayons gamma. Sous l'effet des deux types de rayonnements, il s'est produit des mutations de vert normal dominant en chlorina, sous forme de bandes longitudinales. Sur les feuilles et les tiges des heterozygotes X{sub 1}. Environ 80% des semences ont germe dans le lot temoin ainsi que dans les deux lots ayant recu la plus faible dose de neutrons et de rayons gamma; les taux de germination ont diminue a mesure qu'augmentaient les doses de neutrons et de rayons gamma. En outre, on a observe un phenomene analogue au debut de lacroissance de la plantule, qui etait progressivement inhibee a mesure qu'augmentait la dose de rayonnement. Les resultats obtenus montrent que l'irradiation par les neutrons est environ 13 fois plus efficace que celle par les rayons gamma. Le taux de survie des semences non irradiees du lo t temoin a e te de 90% environ; 60 a 80% des plantules ont survecu aux doses de 0,5 et 1,0 krad de neutrons; toutes les plantilles irradiees par les rayons gamma ont survecu. En revanche, 4% seulement des plantules ont survecu a 1,4 krad de neutrons. L'auteur n 'a pas observe de mutations chez les plantes du lo t temoin; le nombre des plantes a talles rayees a augmente en meme temps que les doses des deux types