Simulation of Neutron-Induced Prompt Gamma-ray Spectra Emitted from Fake Tungsten Gold Bar

Energy Technology Data Exchange (ETDEWEB)

Lee, K. M.; Sum, G. M. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Fake gold bars on the market cannot be identified easily without testing because they have the same appearance as a pure gold bar. A non-destructive monitoring method is needed to avoid the trading of fake gold bars on the market. The ultimate goal of this study is to find a fake gold bar detection method using a PGAA (Prompt Gamma Activation Analysis). Using existing data, the number of neutron capture for gold and tungsten in fake tungsten gold bar was calculated and a Monte Carlo simulation for the prompt neutron-induced gamma-ray spectra was conducted. A simulation for neutron-induced prompt gamma-rays spectra when a neutron beam is irradiated onto pure and fake gold bars was successfully conducted. Through a comparison between the prompt gamma-ray spectra of the pure gold bar and those of the fake gold bar, it was concluded that the observation of prompt high-energy gamma-rays from tungsten or a reduction of prompt gamma-rays from gold can be evidence of a fake gold bar. The possibility for detecting a fake gold bar using a PGAA facility was verified.

Simulation of Neutron-Induced Prompt Gamma-ray Spectra Emitted from Fake Tungsten Gold Bar

International Nuclear Information System (INIS)

Lee, K. M.; Sum, G. M.

2016-01-01

Fake gold bars on the market cannot be identified easily without testing because they have the same appearance as a pure gold bar. A non-destructive monitoring method is needed to avoid the trading of fake gold bars on the market. The ultimate goal of this study is to find a fake gold bar detection method using a PGAA (Prompt Gamma Activation Analysis). Using existing data, the number of neutron capture for gold and tungsten in fake tungsten gold bar was calculated and a Monte Carlo simulation for the prompt neutron-induced gamma-ray spectra was conducted. A simulation for neutron-induced prompt gamma-rays spectra when a neutron beam is irradiated onto pure and fake gold bars was successfully conducted. Through a comparison between the prompt gamma-ray spectra of the pure gold bar and those of the fake gold bar, it was concluded that the observation of prompt high-energy gamma-rays from tungsten or a reduction of prompt gamma-rays from gold can be evidence of a fake gold bar. The possibility for detecting a fake gold bar using a PGAA facility was verified

Timing of Pulsed Prompt Gamma Rays for Background Discrimination

International Nuclear Information System (INIS)

Hueso-Gonzalez, F.; Golnik, C.; Berthel, M.; Dreyer, A.; Kormoll, T.; Rohling, H.; Pausch, G.; Enghardt, W.; Fiedler, F.; Heidel, K.; Schoene, S.; Schwengner, R.; Wagner, A.

2013-06-01

In the context of particle therapy, particle range verification is a major challenge for the quality assurance of the treatment. One approach is the measurement of the prompt gamma rays resulting from the tissue irradiation. A Compton camera based on several planes of position sensitive gamma ray detectors, together with an imaging algorithm, is expected to reconstruct the prompt gamma ray emission density profile, which is correlated with the dose distribution. At Helmholtz- Zentrum Dresden-Rossendorf (HZDR) and OncoRay, a camera prototype has been developed consisting of two scatter planes (CdZnTe cross strip detectors) and an absorber plane (Lu 2 SiO 5 block detector). The data acquisition is based on VME electronics and handled by software developed on the ROOT platform. The prototype was tested at the linear electron accelerator ELBE at HZDR, which was set up to produce bunched bremsstrahlung photons. Their spectrum has similarities with the one expected from prompt gamma rays in the clinical case, and these are also bunched with the accelerator frequency. The time correlation between the pulsed prompt photons and the measured signals was used for background discrimination, achieving a time resolution of 3 ns (2 ns) FWHM for the CZT (LSO) detector. A time-walk correction was applied for the LSO detector and improved its resolution to 1 ns. In conclusion, the detectors are suitable for time-resolved background discrimination in pulsed clinical particle accelerators. Ongoing tasks are the test of the imaging algorithms and the quantitative comparison with simulations. Further experiments will be performed at proton accelerators. (authors)

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

Measurement of prompt fission gamma-ray spectra in fast neutron-induced fission

International Nuclear Information System (INIS)

Laborie, J.M.; Belier, G.; Taieb, J.

2012-01-01

Knowledge of prompt fission gamma-ray emission has been of major interest in reactor physics for a few years. Since very few experimental spectra were ever published until now, new measurements would be also valuable to improve our understanding of the fission process. An experimental method is currently being developed to measure the prompt fission gamma-ray spectrum from some tens keV up to 10 MeV at least. The mean multiplicity and total energy could be deduced. In this method, the gamma-rays are measured with a bismuth germanate (BGO) detector which has the advantage to present a high P/T ratio and a high efficiency compared to other gamma-ray detectors. The prompt fission neutrons are rejected by the time of flight technique between the BGO detector and a fission trigger given by a fission chamber or a scintillating active target. Energy and efficiency calibration of the BGO detector were carried out up to 10.76 MeV by means of the Al-27(p, gamma) reaction. First prompt fission gamma-ray spectrum measurements performed for the spontaneous fission of Cf-252 and for 1.7 and 15.6 MeV neutron-induced fission of U-238 at the CEA, DAM, DIF Van de Graaff accelerator, will be presented. (authors)

Proton current measurements using the prompt gamma ray diagnostic technique

International Nuclear Information System (INIS)

Leeper, R.J.; Burns, E.J.T.; Johnson, D.J.; McMurtry, W.M.

1981-01-01

Prompt gamma ray signals from the nuclear reaction 7 Li(p,γ) 8 Be have been used to make time resolved proton current measurements. In these measurements, the proton beam was allowed to strike cylindrical thick lithium metal targets. The time integrated proton current was measured using gamma activation of copper via the reaction 63 Cu(γ,n) 62 Cu(β+). The positron activity of the copper sample was easily measured using coincidence counting techniques. The number of 62 Cu atoms produced per proton incident on a thick Li metal target was determined with separate calibration runs performed on the Sandia 2.5 MeV Van de Graaff accelerator. The time history of the prompt gamma production was measured using six EGG NPM-54 scintillator photomultiplier combinations shielded by 96.5 cm of concrete and 5.1 cm of Pb. The use of six scintillator photomultiplier combinations was necessary to increase the statistical precision of the data. The normalization of the prompt gamma time history data with the total time integrated proton-current measurement yielded the absolute time resolved proton current on target. Data from runs performed on the Sandia Proto I accelerator will be presented

Cement analysis by particle-induced prompt photon spectrometry: comparison of the effect of different charged particle beams

International Nuclear Information System (INIS)

Gihwala, D.; Peisach, M.

1985-01-01

Standard cements were analysed by particle-induced prompt photon spectrometry (PIPPS) using 4,75-MeV protons, 5-MeV 4 He+ ions, and 2-MeV deuterons. Precision and sensitivity attainable were compared. Protons and alpha-particles were comparable for the determination of F, Na, Mg and Si. Protons were preferred for P and Ca, and alpha-particles for the direct determination of O. Sources of interference are discussed with particular reference to delayed gamma-ray emission from deuteron bombardment

Development of prompt gamma measurement system for in vivo proton beam range verification

International Nuclear Information System (INIS)

Min, Chul Hee

2011-02-01

In radiation therapy, most research has focused on reducing unnecessary radiation dose to normal tissues and critical organs around the target tumor volume. Proton therapy is considered to be one of the most promising radiation therapy methods with its physical characteristics in the dose distribution, delivering most of the dose just before protons come to rest at the so-named Bragg peak; that is, proton therapy allows for a very high radiation dose to the tumor volume, effectively sparing adjacent critical organs. However, the uncertainty in the location of the Bragg peak, coming from not only the uncertainty in the beam delivery system and the treatment planning method but also anatomical changes and organ motions of a patient, could be a critical problem in proton therapy. In spite of the importance of the in vivo dose verification to prevent the misapplication of the Bragg peak and to guarantee both successful treatment and patient safety, there is no practical methodology to monitor the in vivo dose distribution, only a few attempts have been made so far. The present dissertation suggests the prompt gamma measurement method for monitoring of the in vivo proton dose distribution during treatment. As a key part of the process of establishing the utility of this method, the verification of the clear relationship between the prompt gamma distribution and the proton dose distribution was accomplished by means of Monte Carlo simulations and experimental measurements. First, the physical properties of prompt gammas were investigated on the basis of cross-section data and Monte Carlo simulations. Prompt gammas are generated mainly from proton-induced nuclear interactions, and then emitted isotropically in less than 10 -9 sec at energies up to 10 MeV. Simulation results for the prompt gamma yield of the major elements of a human body show that within the optimal energy range of 4-10 MeV the highest number of prompt gammas is generated from oxygen, whereas over the

Prompt Gamma Ray Spectroscopy for process monitoring

International Nuclear Information System (INIS)

Zoller, W.H.; Holmes, J.L.

1991-01-01

Prompt Gamma Ray Spectroscopy (PGRS) is a very powerful analytical technique able to measure many metallic, contamination problem elements. The technique involves measurement of gamma rays that are emitted by nuclei upon capturing a neutron. This method is sensitive not only to the target element but also to the particular isotope of that element. PGRS is capable of measuring dissolved metal ions in a flowing system. In the field, isotopic neutron sources are used to produce the desired neutron flux ( 252 Cf can produce neutron flux of the order of 10 8 neutrons/cm 2 --sec.). Due to high penetrating power of gamma radiation, high efficiency gamma ray detectors can be placed in an appropriate geometry to maximize sensitivity, providing real-time monitoring with low detection level capabilities

GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Straalberg, E. (ed.) (Institute for Energy Technolgy (Norway)); Berg, K. (National Institute of Radiation Protection (Denmark)); Dowdall, M. (Norwegian Radiation Protection Authority (Norway)) (and others)

2010-11-15

The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

International Nuclear Information System (INIS)

Straelberg, E.; Berg, K.; Dowdall, M.

2010-11-01

The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Prompt gamma neutron activation analysis

International Nuclear Information System (INIS)

Goswami, A.

2003-01-01

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

Coincidence gamma-ray spectrometry

DEFF Research Database (Denmark)

Markovic, Nikola; Roos, Per; Nielsen, Sven Poul

2017-01-01

Gamma-ray spectrometry with high-purity germanium (HPGe) detectors is often the technique of choice in an environmental radioactivity laboratory. When measuring environmental samples associated activities are usually low so an important parameter that describes the performance of the spectrometer...... for a nuclide of interest is the minimum detectable activity (MDA). There are many ways for lowering the MDAs in gamma spectrometry. Recently, developments of fast and compact digital acquisition systems have led to growing number of multiple HPGe detector spectrometers. In these applications all detected...

Handbook on Mobile Gamma-ray Spectrometry

DEFF Research Database (Denmark)

Aage, Helle Karina; Korsbech, Uffe C C

2003-01-01

Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing......Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing...

Application of prompt gamma-ray activation analysis

Energy Technology Data Exchange (ETDEWEB)

Chung, Yong Sam; Park, Kwang Won; Moon, Jong Hwa; Kim, Sun Ha; Baek, Sung Ryel [Korea Atomic Energy Research Institute, Taejeon (Korea)

2002-03-01

This technical report is written for the promotion to utilization of prompt gamma-ray activation analysis facility to be installed in HANARO reactor. It is described for a practical aspects including experiment and equipments, methodology, current status of the research and development and its applications. 102 refs., 32 figs., 25 tabs. (Author)

GammaSem Proceedings - A Nordic seminar for users of gamma spectrometry

International Nuclear Information System (INIS)

Nunez, P.; Klemola, S.; Nielsen, Sven P.; Palsson, S.E.; Israelson, C.

2010-03-01

The project GammaSem was proposed to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and to establish a network of users of gamma spectrometry in the Nordic countries, thereby strengthening the collaboration and improving all participants' competence in practical gamma spectrometry. The seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 75 people participated; representing 34 different universities, commercial companies, research institutes and also all Nordic authorities. During the seminar several key issues for follow-up were identified and working groups for addressing the identified problems were established. The working groups were: 1) Uncertainties and detections of limits 2) True summing coincidence 3) Monte Carlo simulations and efficiency transfer 4) Absorption (density corrections and geometries) 5) Mobile gamma spectrometry systems 6) Nuclear forensics (on special samples and special parts of the spectra). The identified topics will form the basis for the agenda of the next seminar in 2010. There, the different working groups will be invited to present their ideas/solutions to the relevant problems. (author)

GammaSem Proceedings - A Nordic seminar for users of gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Nunez, P. (ed.) (Institute for Energy Technology (IFE) (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 (IS)); Israelson, C. (National Institute of Radiation Protection (Denmark))

2010-03-15

The project GammaSem was proposed to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and to establish a network of users of gamma spectrometry in the Nordic countries, thereby strengthening the collaboration and improving all participants' competence in practical gamma spectrometry. The seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 75 people participated; representing 34 different universities, commercial companies, research institutes and also all Nordic authorities. During the seminar several key issues for follow-up were identified and working groups for addressing the identified problems were established. The working groups were: 1) Uncertainties and detections of limits 2) True summing coincidence 3) Monte Carlo simulations and efficiency transfer 4) Absorption (density corrections and geometries) 5) Mobile gamma spectrometry systems 6) Nuclear forensics (on special samples and special parts of the spectra). The identified topics will form the basis for the agenda of the next seminar in 2010. There, the different working groups will be invited to present their ideas/solutions to the relevant problems. (author)

Development of prompt gamma activation analysis

International Nuclear Information System (INIS)

Olmez, I.

1982-01-01

Application of prompt gamma-activation analysis to some environmental samples and NBS's standard reference materials were examined, using NBS reactor and the technique developed by the nuclear chemistry group of the University of Maryland. Concentration of several elements, Cd, B, S, Se, Sb, Zn, Ba, Cr, Cs, Co, Si, Hf, Ce, Yb, Lu, Th, Sc, Eu, Fe, Ta and Rb, were determined by both PGAA and INAA. (author)

Prompt gamma-ray analysis of chlorine in superpozz cement concrete

Energy Technology Data Exchange (ETDEWEB)

Naqvi, A.A., E-mail: aanaqvi@kfupm.edu.sa [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Kalakada, Zameer [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Al-Matouq, Faris A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Maslehuddin, M. [Center for Engineering Research, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Al-Amoudi, O.S.B. [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Ur-Rehman, Khateeb [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

2012-11-21

The chlorine concentration in Superpozz (SPZ) cement concrete was analyzed using a newly designed prompt gamma-ray neutron activation (PGNAA) setup utilizing a portable neutron generator. The setup, which mainly consists of a neutron source along with its moderator placed side by side with a shielded gamma-ray detector, allows determining chloride concentration in a concrete structure from one side. The setup has been tested through chlorine detection in chloride-contaminated Superpozz (SPZ) cement concrete specimens using 6.11 and 2.86{+-}3.10 MeV chlorine prompt gamma-rays. The optimum 0.032{+-}0.012 wt% value of Minimum Detectable Concentration (MDC) of chlorine in SPZ cement concrete measured in this study shows a successful application of a portable neutron generator in chloride analysis of concrete structure for corrosion studies.

Use of prompt gamma emissions from polyethylene to estimate neutron ambient dose equivalent

Energy Technology Data Exchange (ETDEWEB)

Priyada, P.; Sarkar, P.K., E-mail: pradip.sarkar@manipal.edu

2015-06-11

The possibility of using measured prompt gamma emissions from polyethylene to estimate neutron ambient dose equivalent is explored theoretically. Monte Carlo simulations have been carried out using the FLUKA code to calculate the response of a high density polyethylene cylinder to emit prompt gammas from interaction of neutrons with the nuclei of hydrogen and carbon present in polyethylene. The neutron energy dependent responses of hydrogen and carbon nuclei are combined appropriately to match the energy dependent neutron fluence to ambient dose equivalent conversion coefficients. The proposed method is tested initially with simulated spectra and then validated using experimental measurements with an Am–Be neutron source. Experimental measurements and theoretical simulations have established the feasibility of estimating neutron ambient dose equivalent using measured neutron induced prompt gammas emitted from polyethylene with an overestimation of neutron dose at very low energies. - Highlights: • A new method for estimating H{sup ⁎}(10) using prompt gamma emissions from HDPE. • Linear combination of 2.2 MeV and 4.4 MeV gamma intensities approximates DCC (ICRP). • Feasibility of the method was established theoretically and experimentally. • The response of the present technique is very similar to that of the rem meters.

Gamma spectrometry of infinite 4Π geometry

International Nuclear Information System (INIS)

Nordemann, D.J.R.

1987-07-01

Owing to the weak absorption og gamma radiation by matter, gamma-ray spectrometry may be applied to samples of great volume. A very interesting case is that of the gamma-ray spectrometry applied with 4Π geometry around the detector on a sample assumed to be of infinite extension. The determination of suitable efficiencies allows this method to be quantitative. (author) [pt

Applied gamma-ray spectrometry

CERN Document Server

Dams, R; Crouthamel, Carl E

1970-01-01

Applied Gamma-Ray Spectrometry covers real life application of the gamma-ray and the devices used in their experimental studies. This book is organized into 9 chapters, and starts with discussions of the various decay processes, the possible interaction mechanisms of gamma radiation with matter, and the intrinsic and extrinsic variables, which affect the observed gamma-ray and X-ray spectra. The subsequent chapters deal with the properties and fabrication of scintillation detectors, semiconductor detectors, and proportional gas counters. These chapters present some of the most widely utilized

Gamma-ray spectrometry applied to down-hole logging

International Nuclear Information System (INIS)

Dumesnil, P.; Umiastowsky, K.

1983-11-01

Gamma-ray spectrometry permits to improve the accuracy of natural gamma, gamma-gamma and neutron-gamma geophysical measurements. The probe developed at Centre d'Etudes Nucleaires de Saclay allows down-hole gamma-ray spectrometry. Among others, this probe can be applied to the uranium content determination by selective natural gamma method, down-hole determination of the ash content in the coal by gamma-gamma selective method and elemental analysis by neutron-gamma method. For the calibration and an exact interpretation of the measurements it is important to know the gamma-ray and neutron characteristics of the different kinds of rocks considered as probabilistic variables

Signal and Noise Delineation for Prompt-Gamma Detection during Hadrontherapy

International Nuclear Information System (INIS)

Chin, M.-P.W.; Cerutti, F.; Ferrari, A.; Garcia-Ortega, P.; Sala, P.-R.

2013-06-01

Proton and carbon therapies of a human brain were simulated using FLUKA, with particular emphasis on treatment monitoring using the prompt gamma method where activities of the source proton/carbon in the patient's body are to be extracted from the positional profile of exit photons. Tissue heterogeneity ranging from hydrogen to zinc was represented in a VIP-Man anthropomorphic voxel phantom. Each photon exiting the head was scored with ancestry attributes such as the particle type of its parent, the originating collision type and site. These data, not accessible via physical detectors, were analysed to characterise the escaping photons, delineating signal from noise according to the gamma origin and scatter history. Combinations of energy, geometry, time and angle filters, aided by ray-tracing, were studied for the optimal compromise between a sufficiently featured exit profile and a statistically adequate count. These will be put in context with ongoing research in the field; our perspective for the prompt gamma method will be discussed in detail. (authors)

Application of gamma spectrometry survey and discussion on data processing

International Nuclear Information System (INIS)

Li Ji'an; He Jianguo

2008-01-01

This paper analyzed and discussed the different opinions about the measured parameters of gamma spectrometry data, introduced the effect of gamma spectrometry survey to the search for sandstone type uranium deposit. The author believes that it is very necessary to perform some ground gamma spectrometry survey and enforce the development and application of airborne radiometric data so as to carry out the role of gamma spectrometry in the exploration of sandstone type uranium deposit. (authors)

Assessment of Geant4 Prompt-Gamma Emission Yields in the Context of Proton Therapy Monitoring

Science.gov (United States)

Pinto, Marco; Dauvergne, Denis; Freud, Nicolas; Krimmer, Jochen; Létang, Jean M.; Testa, Etienne

2016-01-01

Monte Carlo tools have been long used to assist the research and development of solutions for proton therapy monitoring. The present work focuses on the prompt-gamma emission yields by comparing experimental data with the outcomes of the current version of Geant4 using all applicable proton inelastic models. For the case in study and using the binary cascade model, it was found that Geant4 overestimates the prompt-gamma emission yields by 40.2 ± 0.3%, even though it predicts the prompt-gamma profile length of the experimental profile accurately. In addition, the default implementations of all proton inelastic models show an overestimation in the number of prompt gammas emitted. Finally, a set of built-in options and physically sound Geant4 source code changes have been tested in order to try to improve the discrepancy observed. A satisfactory agreement was found when using the QMD model with a wave packet width equal to 1.3 fm2. PMID:26858937

Determination of Proton dose distal fall-off location by detecting right-angled prompt gamma rays

International Nuclear Information System (INIS)

Seo, Kyu Seok

2006-02-01

The proton beam has a unique advantage over the electron and photon beams in that it can give very high radiation dose to the tumor volume while effectively sparing the neighboring healthy tissue and organs. The number of proton therapy facility is very rapidly increasing in the world. And now the 230 MeV cyclotron facility for proton therapy is constructing at National Cancer Center, this facility until 2006. The distal fall-off location of proton beam is simply calculated by analytical method, but this method has many uncertain when anatomical structure is very complicated. It is very important to know the exact position of the proton beam distal fall-off, or beam range, in the patient's body for both the safety of the patient and the effectiveness of the treatment itself. In 2003, Stichelbaut and Jongen reported the possibility of using the right-angled prompt gamma rays, which are emitted at 90 .deg. from the incident proton beam direction, to determine the position of the proton beam distal fall-off. They studied the interactions of the protons and other secondary particles in a water phantom and concluded that there is a correlation between the position of the distal fall-off and the distribution of the right-angled prompt gamma rays. We have recently designed a prompt gamma scanning system to measure the proton range in situ by using Monte Carlo technique employing MCNPX, FLUKA, and Sabrina TM . The prompt gamma scanning system was designed to measure only the right-angled prompt gamma rays passing through a narrow collimation hole in order to correlate the position with the dose distribution. The collimation part of the scanning system, which has been constructed to measure the gamma rays at 70 MeV of proton energy, is made of a set of paraffin, boron carbide, and lead layers to shield the high-energy neutrons and secondary photons. After the different proton energies and SOBP beam widths are irradiated at the water phantom. we detected prompt gamma at 5 cm

Urban gamma spectrometry. Report 2

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

Urban gamma spectrometry has been given only minor attention with the focus being on rural gamma spectrometry. However, in recent years the Nordic emergency management authorities have turned focus towards border control and lost or stolen sources. Gamma spectra measured in urban areas are characterized by a wide variety of spectrum shapes and very fast changes in environmental background. In 2004 a Danish CGS (Carborne Gamma Spectrometry) survey took place in Copenhagen. It was found that gamma spectrometry in urban areas is far more complicated to interpret than had previously been thought and a new method 'Fitting with Spectral Components', FSC, based on NASVD, was tested with some success. In Finland, a database 'LINSSI' has been developed for spectral data management. In CGS search mode a 'peak hypothesis test' is applied to the measured spectra. This system was tested during the Helsinki 2005 Athletics World Championship and it provides fast and reliable automated alarms for intermediate and high level signals. In Sweden mobile detector systems are used for border controls and problems are encountered when making measurement in harbour, container areas. The methods for handling data and for interpretation of urban gamma spectrometry measurements were compared and tested on the same data sets from Copenhagen and Helsinki. Software tools were developed for converting data between the Finnish LINSSI database and the binary file formats used in Denmark and Sweden. The Processing methods used at DTU and STUK have different goals. The ASSS and FSC methods are designed to optimize the overall detection capability of the system, while sacrificing speed, usability and to a certain level robustness. These methods cannot always be used for real time analysis. The Peak Significance method is designed to give robust alarms in real time, while sacrificing some of the detection capability. Thus these methods are not interchangeable, but rather

Urban gamma spectrometry. Report 2

International Nuclear Information System (INIS)

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

2009-06-01

Urban gamma spectrometry has been given only minor attention with the focus being on rural gamma spectrometry. However, in recent years the Nordic emergency management authorities have turned focus towards border control and lost or stolen sources. Gamma spectra measured in urban areas are characterized by a wide variety of spectrum shapes and very fast changes in environmental background. In 2004 a Danish CGS (Carborne Gamma Spectrometry) survey took place in Copenhagen. It was found that gamma spectrometry in urban areas is far more complicated to interpret than had previously been thought and a new method 'Fitting with Spectral Components', FSC, based on NASVD, was tested with some success. In Finland, a database 'LINSSI' has been developed for spectral data management. In CGS search mode a 'peak hypothesis test' is applied to the measured spectra. This system was tested during the Helsinki 2005 Athletics World Championship and it provides fast and reliable automated alarms for intermediate and high level signals. In Sweden mobile detector systems are used for border controls and problems are encountered when making measurement in harbour, container areas. The methods for handling data and for interpretation of urban gamma spectrometry measurements were compared and tested on the same data sets from Copenhagen and Helsinki. Software tools were developed for converting data between the Finnish LINSSI database and the binary file formats used in Denmark and Sweden. The Processing methods used at DTU and STUK have different goals. The ASSS and FSC methods are designed to optimize the overall detection capability of the system, while sacrificing speed, usability and to a certain level robustness. These methods cannot always be used for real time analysis. The Peak Significance method is designed to give robust alarms in real time, while sacrificing some of the detection capability. Thus these methods are not interchangeable, but rather complementary. An ideal system

Prompt-gamma spectrometry for the optimization of reactor neutron beams in biomedical research

International Nuclear Information System (INIS)

Borisov, G.I.; Komkov, M.M.; Leonov, V.F.

1988-01-01

In order to select the optimal spectral composition and size for the reactor neutron beams applied to in vivo analysis and therapy in biomedical research it is necessary to determine the spatial slow-neutron flux distributions produced by the beam in the irradiated object and to calculate or measure the neutron dose equivalents of both the original spectrum and the moderated neutrons. In this study the maximum neutron dose equivalents are found by spectrometry of the prompt-γ emission from the interaction of neutrons with atomic nuclei in the irradiated object. Different spectral distributions were produced by using an unfiltered beam together with filters of quartz, cadmium, 10 B, iron, aluminum, and sulfur. The phantom used was a tank filled with an aqueous solution of urea. Cadmium-containing organs were simulated. For in vivo neutron-activation analysis of human tissues at a depth of 2-5 cm it was found advisable to use neutrons of 20-40 keV mean energy with a beam area of at least 45 cm 2

Ultra-high energy cosmic rays and prompt TeV gamma rays from ...

Indian Academy of Sciences (India)

physics pp. 789-792. Ultra-high energy cosmic rays and prompt. TeV gamma rays from gamma ray bursts ... The origin of the observed ultra-high energy cosmic ray (UHECR) events with ... are proton and electron rest mass, respectively.

Determination of protein content in grains by radioactive thermal neutron capture prompt gamma rays analysis

International Nuclear Information System (INIS)

Carbonari, A.W.

1983-01-01

The radioactive thermal neutron capture prompt gamma rays technique can be used to determinate the nitrogen content in grains without chemical destruction, with good precision and relative rapidity. This determination is based on the detection of prompt gamma rays emitted by the 14 N(n,γ) 15 N reaction product. The samples has been irradiated the tanGencial tube of the IEA-R1 research reator and a pair spectrometer has been used for the detection of the prompt gamma rays. The nitrogen content is determinated in several samples of soybean, commonbean, peas and rice, and the results is compared with typical nitrogen content for each grain. (Autor) [pt

Programmer for automatic gamma spectrometry; Ordonnateur de sequence pour spectrometrie gamma automatique

Energy Technology Data Exchange (ETDEWEB)

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

1968-04-01

With this apparatus, which is constructed of logical integrated circuits, it is possible both to synchronize an automatic gamma spectrometry assembly and to record the spectra on punched cards. An IBM terminal will make it possible with the help of analysis by the least squares method and by a direct dialogue with an IBM 360 computer to obtain analytical results almost instantaneously. (author) [French] Cet appareil, realise en circuits integres logiques, permet d'une part de synchroniser un ensemble automatique de spectrometrie gamma et d'autre part d'enregistrer les spectres sur cartes perforees. Un terminal IBM permettra, a l'aide d'un programme d'analyse par la methode des moindres carres et par un dialogue direct avec un ordinateur IBM 360, de disposer presque intanstanement des resultats des analyses. (auteur)

Polarization of the prompt gamma-ray emission from the gamma-ray burst of 6 December 2002.

Science.gov (United States)

Coburn, Wayne; Boggs, Steven E

2003-05-22

Observations of the afterglows of gamma-ray bursts (GRBs) have revealed that they lie at cosmological distances, and so correspond to the release of an enormous amount of energy. The nature of the central engine that powers these events and the prompt gamma-ray emission mechanism itself remain enigmatic because, once a relativistic fireball is created, the physics of the afterglow is insensitive to the nature of the progenitor. Here we report the discovery of linear polarization in the prompt gamma-ray emission from GRB021206, which indicates that it is synchrotron emission from relativistic electrons in a strong magnetic field. The polarization is at the theoretical maximum, which requires a uniform, large-scale magnetic field over the gamma-ray emission region. A large-scale magnetic field constrains possible progenitors to those either having or producing organized fields. We suggest that the large magnetic energy densities in the progenitor environment (comparable to the kinetic energy densities of the fireball), combined with the large-scale structure of the field, indicate that magnetic fields drive the GRB explosion.

Buildup factor and mechanical properties of high-density cement mixed with crumb rubber and prompt gamma ray study

Science.gov (United States)

Aim-O, P.; Wongsawaeng, D.; Tancharakorn, S.; Sophon, M.

2017-09-01

High-density cement mixed with crumb rubber has been studied to be a gamma ray and neutron shielding material, especially for photonuclear reactions that may occur from accelerators where both types of radiation exist. The Buildup factors from gamma ray scattering, prompt and secondary gamma ray emissions from neutron capture and mechanical properties were evaluated. For buildup factor studies, two different geometries were used: narrow beam and broad beam. Prompt Gamma Neutron Activation Analysis (PGNAA) was carried out to determine the prompt and secondary gamma ray emissions. The compressive strength of samples was evaluated by using compression testing machine which was central point loading crushing test. The results revealed that addition of crumb rubber increased the buildup factor. Gamma ray spectra following PGNAA revealed no prompt or secondary gamma ray emission. Mechanical testing indicated that the compressive strength of the shielding material decreased with increasing volume percentage of crumb rubber.

Prompt gamma-based neutron dosimetry for Am-Be and other workplace neutron spectra

International Nuclear Information System (INIS)

Udupi, Ashwini; Panikkath, Priyada; Sarkar, P.K.

2016-01-01

A new field-deployable technique for estimating the neutron ambient dose equivalent H*(10) by using the measured prompt gamma intensities emitted from borated high-density polyethylene (BHDPE) and the combination of normal HDPE and BHDPE with different configurations have been evaluated in this work. Monte Carlo simulations using the FLUKA code has been employed to calculate the responses from the prompt gammas emitted due to the monoenergetic neutrons interacting with boron, hydrogen, and carbon nuclei. A suitable linear combination of these prompt gamma responses (dose conversion coefficient (DCC)-estimated) is generated to approximate the International Commission on Radiological Protection provided DCC using the cross-entropy minimization technique. In addition, the shape and configurations of the HDPE and BHDPE combined system are optimized using the FLUKA code simulation results. The proposed method is validated experimentally, as well as theoretically, using different workplace neutron spectra with a satisfactory outcome. (author)

The progress of neutron induced prompt gamma analysis technique in 1988-2002

International Nuclear Information System (INIS)

Liu Yuren; Jing Shiwei

2003-01-01

The new development of the neutron induced prompt gamma-ray analysis (NIPGA) technology in 1988-2002 are described. The pulse fast-thermal neutron activation analysis method, which utilizes the inelastic reaction and capture reaction jointly is employed to measure the elemental content in the material more efficiently. The lifetime of the neutron generator is more than 10000 h and the capability of HPGe, TeZeCd and MCA (multi-channel analyser) reaches the high level. At the same time, Monte Carlo Library least-square method is used to solve the nonlinearity problem in the PGNAA (Prompt Gamma Neutron Activation Analysis)

Prompt gamma-ray analysis of steel slag in concrete

International Nuclear Information System (INIS)

Naqvi, Akhtar Abbas; Garwan, Muhammad Ahmad; Nagadi, Mahmoud Mohammad; Rehman, Khateeb-ur; Raashid, Mohammad; Masalehuddin Mohiuddin, Mohammad; Al-Amoudi, Omar Saeed Baghabra

2009-01-01

Blast furnace slag (BFS) is added to Portland cement concrete to increase its durability, particularly its corrosion resistance. Monitoring the concentration of BFS in concrete for quality control purposes is desired. In this study, the concentration of BFS in concrete was measured by utilizing an accelerator-based prompt gamma-ray neutron activation analysis (PGNAA) setup. The optimum size of the BFS cement concrete specimen that produces the maximum intensity of gamma rays at the detector location was calculated through Monte Carlo simulations. The simulation results were experimentally validated through the gamma-ray yield measurement from BFS cement concrete specimens having different radii. The concentration of BFS in the cement concrete specimens was assessed through calcium and silicon gamma-ray yield measurement from cement concrete specimens containing 5 to 80 wt% BFS. The yield of calcium gamma rays decreases with increasing BFS concentration in concrete while the yield of silicon gamma rays increases with increasing BFS concentration in concrete. The calcium-to-silicon gamma-ray yield ratio has an inverse relation with BFS concentration in concrete. (author)

Study on dose distribution of therapeutic proton beams with prompt gamma measurement

Energy Technology Data Exchange (ETDEWEB)

Kim, J. W. [National Cancer Center, Seoul (Korea, Republic of); Min, C. H.; Kim, C. H.; Kim, D. K.; Yoon, M. Y. [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2007-03-15

The proton beam has an advantage of the sharp dose falloff in dose distribution called Bragg peak while conventional radiation therapy modalities such as photons exhibit considerable amount of exit dose. To take advantage of this property it is important to know the exact location of the distal dose falloff. An error can cause overdose to the normal tissue or underdose to the tumor volume. The only way of finding out the dose distribution in-situ in particle therapy is to measure the gammas produced by nuclear reactions with tissue materials. Two kinds of gammas can be used: one is prompt gamma and the other is coincident gamma from the positron-emission isotopes. We chose to detect prompt gammas, and developed a prompt gamma scanning system (PGS). The proton beams of the proton therapy facility at National Cancer Center were used. The gamma distribution was compared to the dose distribution measured by an ionization chamber at three different energies of 100, 150, 200 MeV's. The two distributions were well correlated within 1-2 mm. The effect of high-energy neutron appeared as blurred distribution near the distal dose falloff at the energy of 200 MeV. We then tested the PGS shielding design by adding additional layer of paraffin plates outside of the PGS, and found that fast neutrons significantly affect the background level. But the location of the dose fall-off was nearly coincident. The analysis of gamma energy spectrum showed that cut-off energy in gamma counting can be adjusted to enhance the signal to noise ratio. Further the ATOM phantom, which has similar tissue structure to human, was used to investigate the gamma distribution for the case of inhomogeneous matter. The location of dose falloff region was found to be well defined as for water phantom. Next an actual therapy beam, which was produced by the double scattering method, was used, for which the dose falloff by the gamma distribution was completely wiped out by background neutrons. It is not

Measurement and calculation of characteristic prompt gamma ray spectra emitted during proton irradiation

Energy Technology Data Exchange (ETDEWEB)

Polf, J C; Peterson, S; Beddar, S [M D Anderson Cancer Center, Univeristy of Texas, Houston, TX 77030 (United States); McCleskey, M; Roeder, B T; Spiridon, A; Trache, L [Cyclotron Institute, Texas A and M University, College Station, TX 77843 (United States)], E-mail: jcpolf@mdanderson.org

2009-11-21

In this paper, we present results of initial measurements and calculations of prompt gamma ray spectra (produced by proton-nucleus interactions) emitted from tissue equivalent phantoms during irradiations with proton beams. Measurements of prompt gamma ray spectra were made using a high-purity germanium detector shielded either with lead (passive shielding), or a Compton suppression system (active shielding). Calculations of the spectra were performed using a model of both the passive and active shielding experimental setups developed using the Geant4 Monte Carlo toolkit. From the measured spectra it was shown that it is possible to distinguish the characteristic emission lines from the major elemental constituent atoms (C, O, Ca) in the irradiated phantoms during delivery of proton doses similar to those delivered during patient treatment. Also, the Monte Carlo spectra were found to be in very good agreement with the measured spectra providing an initial validation of our model for use in further studies of prompt gamma ray emission during proton therapy. (note)

Evaluation and measurement of prompt k0-factors to use in prompt gamma-ray neutron activation analysis

International Nuclear Information System (INIS)

Goswami, A.; Nair, A.G.C.; Acharya, R.N.; Sudarshan, K.; Scindia, Y.M.; Reddy, A.V.R.; Manohar, S.B.

2000-01-01

The determination of experimental k 0 -factors is important due to uncertainties on absolute values of cross sections and prompt gamma-ray intensities. Determination of absolute full-energy peak detection efficiency and elemental sensitivity are required to obtain experimental k 0 -factor

Determination of the distal dose edge in a human phantom by measuring the prompt gamma distribution: a Monte Carlo study

Energy Technology Data Exchange (ETDEWEB)

Min, Chul Hee; Lee, Han Rim; Yeom, Yeon Su; Cho, Sung Koo; Kim, Chan Hyeong [Hanyang University, Seoul (Korea, Republic of)

2010-06-15

The close relationship between the proton dose distribution and the distribution of prompt gammas generated by proton-induced nuclear interactions along the path of protons in a water phantom was demonstrated by means of both Monte Carlo simulations and limited experiments. In order to test the clinical applicability of the method for determining the distal dose edge in a human body, a human voxel model, constructed based on a body-composition-approximated physical phantom, was used, after which the MCNPX code was used to analyze the energy spectra and the prompt gamma yields from the major elements composing the human voxel model; finally, the prompt gamma distribution, generated from the voxel model and measured by using an array-type prompt gamma detection system, was calculated and compared with the proton dose distribution. According to the results, effective prompt gammas were produced mainly by oxygen, and the specific energy of the prompt gammas, allowing for selective measurement, was found to be 4.44 MeV. The results also show that the distal dose edge in the human phantom, despite the heterogeneous composition and the complicated shape, can be determined by measuring the prompt gamma distribution with an array-type detection system.

Automatic gamma spectrometry analytical apparatus

International Nuclear Information System (INIS)

Lamargot, J.-P.; Wanin, Maurice.

1980-01-01

This invention falls within the area of quantitative or semi-quantitative analysis by gamma spectrometry and particularly refers to a device for bringing the samples into the counting position. The purpose of this invention is precisely to provide an automatic apparatus specifically adapted to the analysis of hard gamma radiations. To this effect, the invention relates to a gamma spectrometry analytical device comprising a lead containment, a detector of which the sensitive part is located inside the containment and additionally comprising a transfer system for bringing the analyzed samples in succession to a counting position inside the containment above the detector. A feed compartment enables the samples to be brought in turn one by one on to the transfer system through a duct connecting the compartment to the transfer system. Sequential systems for the coordinated forward feed of the samples in the compartment and the transfer system complete this device [fr

GPU-based prompt gamma ray imaging from boron neutron capture therapy

International Nuclear Information System (INIS)

Yoon, Do-Kun; Jung, Joo-Young; Suk Suh, Tae; Jo Hong, Key; Sil Lee, Keum

2015-01-01

Purpose: The purpose of this research is to perform the fast reconstruction of a prompt gamma ray image using a graphics processing unit (GPU) computation from boron neutron capture therapy (BNCT) simulations. Methods: To evaluate the accuracy of the reconstructed image, a phantom including four boron uptake regions (BURs) was used in the simulation. After the Monte Carlo simulation of the BNCT, the modified ordered subset expectation maximization reconstruction algorithm using the GPU computation was used to reconstruct the images with fewer projections. The computation times for image reconstruction were compared between the GPU and the central processing unit (CPU). Also, the accuracy of the reconstructed image was evaluated by a receiver operating characteristic (ROC) curve analysis. Results: The image reconstruction time using the GPU was 196 times faster than the conventional reconstruction time using the CPU. For the four BURs, the area under curve values from the ROC curve were 0.6726 (A-region), 0.6890 (B-region), 0.7384 (C-region), and 0.8009 (D-region). Conclusions: The tomographic image using the prompt gamma ray event from the BNCT simulation was acquired using the GPU computation in order to perform a fast reconstruction during treatment. The authors verified the feasibility of the prompt gamma ray image reconstruction using the GPU computation for BNCT simulations

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

Monte Carlo Latching Studies of Prompt-Gamma Detection During Hadrontherapy

CERN Document Server

Chin, M P W; Ferrari, A; Ortega, P G; Sala, P R

2014-01-01

Proton and carbon therapies of a human brain were simulated using FLUKA, with particular emphasis on treatment monitoring using the prompt gamma method where activities of the source proton/carbon in the patient's body are to be extracted from the positional profile of exit photons. Tissue heterogeneity ranging from hydrogen to zinc was represented in a VIP-Man anthropomorphic voxel phantom. Each photon exiting the head was scored with ancestry attributes such as the particle type of its parent, the originating collision type and site. These data, not accessible via physical detectors, were analysed to characterise the escaping photons, delineating signal from noise according to the gamma origin and scatter history. Combinations of energy, geometry, time and angle filters, aided by raytracing, were studied for the optimal compromise between a sufficiently featured exit profile and a statistically adequate count. These will be put in context with ongoing research in the field; our perspective for the prompt ga...

Reduction of Compton background from hydrogen in prompt gamma-ray analysis by multiple photon detection

International Nuclear Information System (INIS)

Toh, Y.; Oshima, M.; Kimura, A.; Koizumi, M.; Furutaka, K.; Hatsukawa, Y.

2008-01-01

Low-energy photons produced by the Compton scattering from hydrogen increase the background in the lower-energy region of the gamma-ray spectrum. This results in an increase in the detection limit for trace elements. In multiple photon detection prompt gamma-ray analysis (MPGA), only those elements that simultaneously emit two or more prompt gamma-rays, which have cascade relation and are emitted within a short interval, can be measured. Therefore, the influence of hydrogen can be reduced. In this study, standard polymer and food samples are measured. The hydrogen background is reduced in MPGA. (author)

Statistical analysis for discrimination of prompt gamma ray peak induced by high energy neutron: Monte Carlo simulation study

International Nuclear Information System (INIS)

Do-Kun Yoon; Joo-Young Jung; Tae Suk Suh; Seong-Min Han

2015-01-01

The purpose of this research is a statistical analysis for discrimination of prompt gamma ray peak induced by the 14.1 MeV neutron particles from spectra using Monte Carlo simulation. For the simulation, the information of 18 detector materials was used to simulate spectra by the neutron capture reaction. The discrimination of nine prompt gamma ray peaks from the simulation of each detector material was performed. We presented the several comparison indexes of energy resolution performance depending on the detector material using the simulation and statistics for the prompt gamma activation analysis. (author)

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)

Use of borated polyethylene to improve low energy response of a prompt gamma based neutron dosimeter

Energy Technology Data Exchange (ETDEWEB)

Priyada, P.; Ashwini, U.; Sarkar, P.K., E-mail: pradip.sarkar@manipal.edu

2016-05-21

The feasibility of using a combined sample of borated polyethylene and normal polyethylene to estimate neutron ambient dose equivalent from measured prompt gamma emissions is investigated theoretically to demonstrate improvements in low energy neutron dose response compared to only polyethylene. Monte Carlo simulations have been carried out using the FLUKA code to calculate the response of boron, hydrogen and carbon prompt gamma emissions to mono energetic neutrons. The weighted least square method is employed to arrive at the best linear combination of these responses that approximates the ICRP fluence to dose conversion coefficients well in the energy range of 10{sup −8} MeV to 14 MeV. The configuration of the combined system is optimized through FLUKA simulations. The proposed method is validated theoretically with five different workplace neutron spectra with satisfactory outcome. - Highlights: • An improved method is proposed for estimating H⁎(10) using prompt gamma emissions. • A combination of BHDPE and HDPE cylinders is used as a sample. • Linear combination of prompt gamma intensities approximates ICRP-DCC closely. • Feasibility of the method was tested theoretically using workplace neutron spectra.

The Prompt and High Energy Emission of Gamma Ray Bursts

International Nuclear Information System (INIS)

Meszaros, P.

2009-01-01

I discuss some recent developments concerning the prompt emission of gamma-ray bursts, in particular the jet properties and radiation mechanisms, as exemplified by the naked-eye burst GRB 080319b, and the prompt X-ray emission of XRB080109/SN2008d, where the progenitor has, for the first time, been shown to contribute to the prompt emission. I discuss then some recent theoretical calculations of the GeV/TeV spectrum of GRB in the context of both leptonic SSC models and hadronic models. The recent observations by the Fermi satellite of GRB 080916C are then reviewed, and their implications for such models are discussed, together with its interesting determination of a bulk Lorentz factor, and the highest lower limit on the quantum gravity energy scale so far.

Detection of mixed-range proton pencil beams with a prompt gamma slit camera

International Nuclear Information System (INIS)

Priegnitz, M; Helmbrecht, S; Fiedler, F; Janssens, G; Smeets, J; Vander Stappen, F; Perali, I; Sterpin, E

2016-01-01

With increasing availability of proton and particle therapy centers for tumor treatment, the need for in vivo range verification methods comes more into the focus. Imaging of prompt gamma rays emitted during the treatment is one of the possibilities currently under investigation. A knife-edge shaped slit camera was recently proposed for this task and measurements proved the feasibility of range deviation detection in homogeneous and inhomogeneous targets. In the present paper, we concentrate on laterally inhomogeneous materials, which lead to range mixing situations when crossed by one pencil beam: different sections of the beam have different ranges. We chose exemplative cases from clinical irradiation and assembled idealized tissue equivalent targets. One-dimensional emission profiles were obtained by measuring the prompt gamma emission with the slit camera. It could be shown that the resulting range deviations can be detected by evaluation of the measured data with a previously developed range deviation detection algorithm. The retrieved value, however, strongly depends on the target composition, and is not necessarily in direct relation to the ranges of both parts of the beam. By combining the range deviation detection with an analysis of the slope of the distal edge of the measured prompt gamma profile, the origin of the detected range deviation, i.e. the mixed range of the beam, is also identified. It could be demonstrated that range mixed prompt gamma profiles exhibit less steep distal slopes than profiles from beams traversing laterally homogeneous material. For future application of the slit camera to patient irradiation with double scattered proton beams, situations similar to the range mixing cases are present and results could possibly apply. (paper)

Elemental analysis of human placenta by neutron irradiation and gamma-ray spectrometry (standard, prompt and fast-neutron)

International Nuclear Information System (INIS)

Ward, N.I.

1987-01-01

Human placental tissue from 100 hospitalized deliveries were analysed for Ag, Al, As, Au, B, Ba, Br, Ca, Cd, Cl, Co, Cr, Cs, Cu, F, Fe, I, Hg, K, La, Mg, Mn, Mo, Na, Ni, Rb, S, Sb, Sc, Se, Sn, Sr, Ti, V, W and Zn using a combination of pre-chemical separation of sodium with hydrated antimony pentoxide and INAA. Boron and Si values were determined using prompt gamma-ray and fast-neutron techniques, respectively. Analysis of NBS-SRM Bovine Liver 1577 and a 'pooled standard' placental tissue for 33 elements showed a good agreement with most coefficients. Only Cd(-) and Zn(+) showed statistically significant correlations with birth weight, gestational age and placental weight. (author) 54 refs.; 3 tables

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.)

Implementation of the Prompt Gamma facility in the ININ; Implementacion de la instalacion del Prompt Gamma en el ININ

Energy Technology Data Exchange (ETDEWEB)

Macias B, L.R.; Delfin L, A.; Aguilar H, F. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

2002-07-01

The Prompt Gamma Neutron Activation Analysis (PGNAA) technique is based on the reaction of a neutron and an atom emitting gamma radiation in an immediate form and it is used for the elemental identification and characterization. This is a non-destructive technique and presents advantages compared with the X-ray fluorescence analysis technique since it has the advantage of the ability for the neutron penetration which allows a complete analysis in volume of material while the X-ray penetration is not very deep, it is superficial and other advantage of PGNAA is that can detects light elements while by mean of the X-ray fluorescence technique it is not possible. In this work it is shown the implementation of this technique un the National Institute of Nuclear Research (ININ) and the way in which this technique is applied with a radiation source of the TRIGA Mark III reactor from which thermal neutrons were isolated. (Author)

Contribution to the study of prompt gamma-rays from fission

International Nuclear Information System (INIS)

Regnier, D.

2013-01-01

This PhD thesis has essentially been motivated by the nuclear heating problematic in reactors. The main goal of this work was the production of methods capable of simulating the prompt gamma emission from fission. First of all, several algorithms for the treatment of the nucleus deexcitation were implemented. They have been successfully tested through various calculations (isomeric branching ratio, total radiative width, etc). These methods were then incorporated in the frame of the fission code FIFRELIN. The tool which results from this work, enables the determination of numerous fission observables in the frame of a single consistent model. A sensitivity study of the results to several numerical and nuclear models has been realized. At last, calculation have been lead for the 252 Cf spontaneous fission and the thermal neutron induced fission of 235 U and 239 Pu. The prompt gamma spectra obtained for those three fissioning systems have been determined. The results are in good agreement with available experimental data, including recent measurements published in 2012 and 2013. (author) [fr

Prompt gamma ray diagnostics and enhanced hadron-therapy using neutron-free nuclear reactions

Science.gov (United States)

Giuffrida, L.; Margarone, D.; Cirrone, G. A. P.; Picciotto, A.; Cuttone, G.; Korn, G.

2016-10-01

We propose a series of simulations about the potential use of Boron isotopes to trigger neutron-free (aneutronic) nuclear reactions in cancer cells through the interaction with an incoming energetic proton beam, thus resulting in the emission of characteristic prompt gamma radiation (429 keV, 718 keV and 1435 keV). Furthermore assuming that the Boron isotopes are absorbed in cancer cells, the three alpha-particles produced in each p-11B aneutronic nuclear fusion reactions can potentially result in the enhancement of the biological dose absorbed in the tumor region since these multi-MeV alpha-particles are stopped inside the single cancer cell, thus allowing to spare the surrounding tissues. Although a similar approach based on the use of 11B nuclei has been proposed in [Yoon et al. Applied Physics Letters 105, 223507 (2014)], our work demonstrate, using Monte Carlo simulations, the crucial importance of the use of 10B nuclei (in a solution containing also 11B) for the generation of prompt gamma-rays, which can be applied to medical imaging. In fact, we demonstrate that the use of 10B nuclei can enhance the intensity of the 718 keV gamma-ray peak more than 30 times compared to the solution containing only 11B nuclei. A detailed explanation of the origin of the different prompt gamma-rays, as well as of their application as real-time diagnostics during a potential cancer treatment, is here discussed.

Design of a facility by neutron activation by spectrometry of prompt gamma

International Nuclear Information System (INIS)

Oliver, R.; Benites L, S.; Montoya Z, M.

1993-01-01

We show the basic design of the facility of PGNAA that we will install in the hall of the peruvian reactor RP-10. The thermal neutron flux (without a gamma filter) will be 2,0 x 10 8 n/cm -2 s -1 at 10 MW of power. The ratio of gamma exposition without gamma filter will be 29 kR/h. (authors). 8 refs., 2 figs

DETECTION OF GAMMA-RAY POLARIZATION IN PROMPT EMISSION OF GRB 100826A

Energy Technology Data Exchange (ETDEWEB)

Yonetoku, Daisuke; Murakami, Toshio; Sakashita, Tomonori; Morihara, Yoshiyuki; Takahashi, Takuya; Fujimoto, Hirofumi; Kodama, Yoshiki [College of Science and Engineering, School of Mathematics and Physics, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192 (Japan); Gunji, Shuichi; Toukairin, Noriyuki [Department of Physics, Faculty of Science, Yamagata University, 1-4-12, Koshirakawa, Yamagata, Yamagata 990-8560 (Japan); Mihara, Tatehiro [Cosmic Radiation Laboratory, RIKEN, 2-1, Hirosawa, Wako City, Saitama 351-0198 (Japan); Toma, Kenji [Department of Earth and Space Science, Osaka University, Toyonaka 560-0043 (Japan); Kubo, Shin, E-mail: yonetoku@astro.s.kanazawa-u.ac.jp [Clear Pulse Co. Ltd., 6-25-17, Chuo, Ohta-ku, Tokyo 143-0024 (Japan); Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1, Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan)

2011-12-20

We report the polarization measurement in prompt {gamma}-ray emission of GRB 100826A with the Gamma-Ray Burst Polarimeter on board the small solar-power-sail demonstrator IKAROS. We detected the firm change of polarization angle (PA) during the prompt emission with 99.9% (3.5{sigma}) confidence level, and the average polarization degree ({Pi}) of 27% {+-} 11% with 99.4% (2.9{sigma}) confidence level. Here the quoted errors are given at 1{sigma} confidence level for the two parameters of interest. The systematic errors have been carefully included in this analysis, unlike other previous reports. Such a high {Pi} can be obtained in several emission models of gamma-ray bursts (GRBs), including synchrotron and photospheric models. However, it is difficult to explain the observed significant change of PA within the framework of axisymmetric jet as considered in many theoretical works. The non-axisymmetric (e.g., patchy) structures of the magnetic fields and/or brightness inside the relativistic jet are therefore required within the observable angular scale of {approx}{Gamma}{sup -1}. Our observation strongly indicates that the polarization measurement is a powerful tool to constrain the GRB production mechanism, and more theoretical works are needed to discuss the data in more detail.

Prompt-gamma detection towards absorbed energy monitoring during hadrontherapy

Energy Technology Data Exchange (ETDEWEB)

Krimmer, J.; Balleyguier, L.; Dauvergne, D.; Mathez, H.; Pinto, M.; Testa, E.; Zoccarato, Y. [Institut de Physique Nucleaire de Lyon, Universite de Lyon, Universite de Lyon 1, IN2P3/CNRS, UMR 5822, F-69622 Villeurbanne cedex (France); Krimmer, J.; Freud, N.; L' etang, J.M. [Universite de Lyon, CREATIS, CNRS UMR 5220, Inserm U1044, INSA - Lyon, Universite Lyon 1, Centre Leon Berard (France); Herault, J.; Amblard, R.; Angellier, G. [Centre Antoine Lacassagne, Cyclotron Biomedical, 227 Avenue de la Lanterne, 06200 Nice (France)

2015-07-01

Hadrontherapy is an emerging technique which exploits the fact that a large quantity of the energy of the incident particles is deposited at the end of their flight path. This allows a conformation of the applied dose to the tumor volume and a simultaneous sparing of surrounding healthy tissue. A real-time control of the ion range during the treatment is possible via the detection of prompt secondary radiation (gamma rays or charged particles). Besides a monitoring of the ion range, the knowledge of the total energy absorbed inside the patient is also of importance for an improvement of the treatment quality. It has been shown that the ambient dose in a treatment room is correlated to the monitoring units, i.e. the number of protons of the beam delivery system. The present study consists in applying time-of-flight (TOF) information to identify prompt gamma-rays generated by interactions inside the patient which provides a direct information on the energy imparted. Results from test measurements will be given, which show that events generated in the nozzle and the target phantom can be discriminated. Furthermore, a standalone detection system is being developed which will be read out by a standard PC. The status of the developments for the corresponding electronics will be presented. (authors)

Plutonium characterisation with prompt high energy gamma-rays from (n,gamma) reactions for nuclear warhead dismantlement verification

Energy Technology Data Exchange (ETDEWEB)

Postelt, Frederik; Gerald, Kirchner [Carl Friedrich von Weizsaecker-Centre for Science and Peace Research, Hamburg (Germany)

2015-07-01

Measurements of neutron induced gammas allow the characterisation of fissile material (i.e. plutonium and uranium), despite self- and additional shielding. Most prompt gamma-rays from radiative neutron capture reactions in fissile material have energies between 3 and 6.5 MeV. Such high energy photons have a high penetrability and therefore minimise shielding and self-absorption effects. They are also isotope specific and therefore well suited to determine the isotopic composition of fissile material. As they are non-destructive, their application in dismantlement verification is desirable. Disadvantages are low detector efficiencies at high gamma energies, as well as a high background of gammas which result from induced fission reactions in the fissile material, as well as delayed gammas from both, (n,f) and(n,gamma) reactions. In this talk, simulations of (n,gamma) measurements and their implications are presented. Their potential for characterising fissile material is assessed and open questions are addressed.

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)

Energy input and response from prompt and early optical afterglow emission in gamma-ray bursts.

Science.gov (United States)

Vestrand, W T; Wren, J A; Wozniak, P R; Aptekar, R; Golentskii, S; Pal'shin, V; Sakamoto, T; White, R R; Evans, S; Casperson, D; Fenimore, E

2006-07-13

The taxonomy of optical emission detected during the critical first few minutes after the onset of a gamma-ray burst (GRB) defines two broad classes: prompt optical emission correlated with prompt gamma-ray emission, and early optical afterglow emission uncorrelated with the gamma-ray emission. The standard theoretical interpretation attributes prompt emission to internal shocks in the ultra-relativistic outflow generated by the internal engine; early afterglow emission is attributed to shocks generated by interaction with the surrounding medium. Here we report on observations of a bright GRB that, for the first time, clearly show the temporal relationship and relative strength of the two optical components. The observations indicate that early afterglow emission can be understood as reverberation of the energy input measured by prompt emission. Measurements of the early afterglow reverberations therefore probe the structure of the environment around the burst, whereas the subsequent response to late-time impulsive energy releases reveals how earlier flaring episodes have altered the jet and environment parameters. Many GRBs are generated by the death of massive stars that were born and died before the Universe was ten per cent of its current age, so GRB afterglow reverberations provide clues about the environments around some of the first stars.

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.

Monte Carlo simulations towards semi-quantitative prompt gamma activation imaging

International Nuclear Information System (INIS)

Kis, Zoltan; Belgya, Tamas; Szentmiklosi, Laszlo

2011-01-01

Numerous non-destructive techniques utilize neutron attenuation, scattering or capture to gain morphological, structural or elemental information about the material under study. However, few attempts have been made so far to use neutron-induced gamma radiation for 3D element mapping. The first ever facility using direct scanning for element imaging was set up at the Budapest Research Reactor. It was shown that the position-sensitive prompt-gamma detection (PGAI) enables us to determine the spatial distribution of major elements. Iterative Monte Carlo simulation technique has also been developed to provide not only qualitative but also semi-quantitative element distribution of a simple object.

Non destructive multi elemental analysis using prompt gamma neutron activation analysis techniques: Preliminary results for concrete sample

Energy Technology Data Exchange (ETDEWEB)

Dahing, Lahasen Normanshah [School of Applied Physics, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia and Malaysian Nuclear Agency (Nuklear Malaysia), Bangi 43000, Kajang (Malaysia); Yahya, Redzuan [School of Applied Physics, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Yahya, Roslan; Hassan, Hearie [Malaysian Nuclear Agency (Nuklear Malaysia), Bangi 43000, Kajang (Malaysia)

2014-09-03

In this study, principle of prompt gamma neutron activation analysis has been used as a technique to determine the elements in the sample. The system consists of collimated isotopic neutron source, Cf-252 with HPGe detector and Multichannel Analysis (MCA). Concrete with size of 10×10×10 cm{sup 3} and 15×15×15 cm{sup 3} were analysed as sample. When neutrons enter and interact with elements in the concrete, the neutron capture reaction will occur and produce characteristic prompt gamma ray of the elements. The preliminary result of this study demonstrate the major element in the concrete was determined such as Si, Mg, Ca, Al, Fe and H as well as others element, such as Cl by analysis the gamma ray lines respectively. The results obtained were compared with NAA and XRF techniques as a part of reference and validation. The potential and the capability of neutron induced prompt gamma as tool for multi elemental analysis qualitatively to identify the elements present in the concrete sample discussed.

Gamma-ray Burst Prompt Correlations: Selection and Instrumental Effects

Science.gov (United States)

Dainotti, M. G.; Amati, L.

2018-05-01

The prompt emission mechanism of gamma-ray bursts (GRB) even after several decades remains a mystery. However, it is believed that correlations between observable GRB properties, given their huge luminosity/radiated energy and redshift distribution extending up to at least z ≈ 9, are promising possible cosmological tools. They also may help to discriminate among the most plausible theoretical models. Nowadays, the objective is to make GRBs standard candles, similar to supernovae (SNe) Ia, through well-established and robust correlations. However, differently from SNe Ia, GRBs span over several order of magnitude in their energetics, hence they cannot yet be considered standard candles. Additionally, being observed at very large distances, their physical properties are affected by selection biases, the so-called Malmquist bias or Eddington effect. We describe the state of the art on how GRB prompt correlations are corrected for these selection biases to employ them as redshift estimators and cosmological tools. We stress that only after an appropriate evaluation and correction for these effects, GRB correlations can be used to discriminate among the theoretical models of prompt emission, to estimate the cosmological parameters and to serve as distance indicators via redshift estimation.

The Monte Carlo simulation of the neutron-induced prompt gamma ray spectroscopy of the CW abandoned by Japan

International Nuclear Information System (INIS)

Wang Bairong; Yang Zhongping; Zhan Wenzhong

2003-01-01

This paper introduced the principle of identifying the chemical weapon abandoned by Japan by neutron-induced prompt gamma ray. Using the MCNP-4C Monte Carlo program, this paper simulated and analyzed the neutron-induced prompt gamma ray spectroscopy of chemical weapon abandoned by Japan, whereby supply important datum and reference for the aftertime deeper research and disposal of Japan-abandoned chemical weapon. (authors)

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

The optimization of gamma spectra processing in prompt gamma neutron activation analysis (PGNAA)

Energy Technology Data Exchange (ETDEWEB)

Pinault, Jean-Louis [IAEA Expert, 96 rue du Port David, 45370 Dry (France)], E-mail: jeanlouis_pinault@hotmail.fr; Solis, Jose [Instituto Peruano de Energia Nuclear, Av. Canada No. 1470, San Borja, Lima 41 (Peru)

2009-04-15

The uncertainty of the elemental analysis is one of the major factors governing the utility of on-line Prompt Gamma Neutron Activation Analysis (PGNAA) in the blending and sorting of bulk materials. In this paper, a general method applicable to Gamma spectra processing is presented and applied to PGNAA in mineral industry. Based on the Fourier transform of spectra and their de-correlation in the Fourier space (the improvement of the conditioning of the correlation matrix), processing of overlapping of characteristic peaks minimizes the propagation of random errors, which optimizes the accuracy and decreases the detection limits of elemental analyses. In comparison with classical methods based on the linear combinations of relevant regions of spectra the improvement may be considerable, especially when several elements are interfering. The method is applied to four case stories covering both borehole logging and on-line analysis on conveyor belt of raw materials.

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)

Application of Principal Component Analysis in Prompt Gamma Spectra for Material Sorting

Energy Technology Data Exchange (ETDEWEB)

Im, Hee Jung; Lee, Yun Hee; Song, Byoung Chul; Park, Yong Joon; Kim, Won Ho

2006-11-15

For the detection of illicit materials in a very short time by comparing unknown samples' gamma spectra to pre-programmed material signatures, we at first, selected a method to reduce the noise of the obtained gamma spectra. After a noise reduction, a pattern recognition technique was applied to discriminate the illicit materials from the innocuous materials in the noise reduced data. Principal component analysis was applied for a noise reduction and pattern recognition in prompt gamma spectra. A computer program for the detection of illicit materials based on PCA method was developed in our lab and can be applied to the PGNAA system for the baggage checking at all ports of entry at a very short time.

A calibration to predict the concentrations of impurities in plutonium oxide by prompt gamma analysis: Revision 1

International Nuclear Information System (INIS)

Narlesky, Joshua E.; Foster, Lynn A.; Kelly, Elizabeth J.; Murray, Roy E. IV

2009-01-01

Over 5,500 containers of excess plutonium-bearing materials have been packaged for long-term storage following the requirements of DOE-STD- 3013. Knowledge of the chemical impurities in the packaged materials is important because certain impurities, such as chloride salts, affect the behavior of the material in storage leading to gas generation and corrosion when sufficient moisture also is present. In most cases, the packaged materials are not well characterized, and information about the chemical impurities is limited to knowledge of the material's processing history. The alpha-particle activity from the plutonium and americium isotopes provides a method of nondestructive self-interrogation to identify certain light elements through the characteristic, prompt gamma rays that are emitted from alpha-particle-induced reactions with these elements. Gamma-ray spectra are obtained for each 3013 container using a highresolution, coaxial high-purity germanium detector. These gamma-ray spectra are scanned from 800 to 5,000 keV for characteristic, prompt gamma rays from the detectable elements, which include lithium, beryllium, boron, nitrogen, oxygen, fluorine, sodium, magnesium, aluminum, silicon, phosphorus, chlorine, and potassium. The lower limits of detection for these elements in a plutonium-oxide matrix increase with atomic number and range from 100 or 200 ppm for the lightest elements such as lithium and beryllium, to 19,000 ppm for potassium. The peak areas from the characteristic, prompt gamma rays can be used to estimate the concentration of the light-element impurities detected in the material on a semiquantitative basis. The use of prompt gamma analysis to assess impurity concentrations avoids the expense and the risks generally associated with performing chemical analysis on radioactive materials. The analyzed containers are grouped by impurity content, which helps to identify high-risk containers for surveillance and in sorting materials before packaging.

Prompt Gamma Radiation from Fragments in the Thermal Fission of 235U

International Nuclear Information System (INIS)

Albinsson, H.; Lindow, L.

1970-06-01

Measurements were made on the gamma radiation emitted from fission fragments in slow neutron induced fission of 235 U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way a decay curve was obtained from which the life-time of one of the gamma-emitting states could be estimated. The relative yield of the gamma-rays was determined as a function of mass for different gamma-ray energy portions and two specific time intervals after the fission events. Comparisons were made with data obtained from 252 Cf-fission. Attention is drawn to some features which seem to be the same in 235 U and 252 Cf-fission

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)

Test of Compton camera components for prompt gamma imaging at the ELBE bremsstrahlung beam

Science.gov (United States)

Hueso-González, F.; Golnik, C.; Berthel, M.; Dreyer, A.; Enghardt, W.; Fiedler, F.; Heidel, K.; Kormoll, T.; Rohling, H.; Schöne, S.; Schwengner, R.; Wagner, A.; Pausch, G.

2014-05-01

In the context of ion beam therapy, particle range verification is a major challenge for the quality assurance of the treatment. One approach is the measurement of the prompt gamma rays resulting from the tissue irradiation. A Compton camera based on several position sensitive gamma ray detectors, together with an imaging algorithm, is expected to reconstruct the prompt gamma ray emission density map, which is correlated with the dose distribution. At OncoRay and Helmholtz-Zentrum Dresden-Rossendorf (HZDR), a Compton camera setup is being developed consisting of two scatter planes: two CdZnTe (CZT) cross strip detectors, and an absorber consisting of one Lu2SiO5 (LSO) block detector. The data acquisition is based on VME electronics and handled by software developed on the ROOT framework. The setup has been tested at the linear electron accelerator ELBE at HZDR, which is used in this experiment to produce bunched bremsstrahlung photons with up to 12.5 MeV energy and a repetition rate of 13 MHz. Their spectrum has similarities with the shape expected from prompt gamma rays in the clinical environment, and the flux is also bunched with the accelerator frequency. The charge sharing effect of the CZT detector is studied qualitatively for different energy ranges. The LSO detector pixel discrimination resolution is analyzed and it shows a trend to improve for high energy depositions. The time correlation between the pulsed prompt photons and the measured detector signals, to be used for background suppression, exhibits a time resolution of 3 ns FWHM for the CZT detector and of 2 ns for the LSO detector. A time walk correction and pixel-wise calibration is applied for the LSO detector, whose resolution improves up to 630 ps. In conclusion, the detector setup is suitable for time-resolved background suppression in pulsed clinical particle accelerators. Ongoing tasks are the quantitative comparison with simulations and the test of imaging algorithms. Experiments at proton

Test of Compton camera components for prompt gamma imaging at the ELBE bremsstrahlung beam

International Nuclear Information System (INIS)

Hueso-González, F; Golnik, C; Berthel, M; Dreyer, A; Enghardt, W; Kormoll, T; Rohling, H; Pausch, G; Fiedler, F; Heidel, K; Schöne, S; Schwengner, R; Wagner, A

2014-01-01

In the context of ion beam therapy, particle range verification is a major challenge for the quality assurance of the treatment. One approach is the measurement of the prompt gamma rays resulting from the tissue irradiation. A Compton camera based on several position sensitive gamma ray detectors, together with an imaging algorithm, is expected to reconstruct the prompt gamma ray emission density map, which is correlated with the dose distribution. At OncoRay and Helmholtz-Zentrum Dresden-Rossendorf (HZDR), a Compton camera setup is being developed consisting of two scatter planes: two CdZnTe (CZT) cross strip detectors, and an absorber consisting of one Lu 2 SiO 5 (LSO) block detector. The data acquisition is based on VME electronics and handled by software developed on the ROOT framework. The setup has been tested at the linear electron accelerator ELBE at HZDR, which is used in this experiment to produce bunched bremsstrahlung photons with up to 12.5 MeV energy and a repetition rate of 13 MHz. Their spectrum has similarities with the shape expected from prompt gamma rays in the clinical environment, and the flux is also bunched with the accelerator frequency. The charge sharing effect of the CZT detector is studied qualitatively for different energy ranges. The LSO detector pixel discrimination resolution is analyzed and it shows a trend to improve for high energy depositions. The time correlation between the pulsed prompt photons and the measured detector signals, to be used for background suppression, exhibits a time resolution of 3 ns FWHM for the CZT detector and of 2 ns for the LSO detector. A time walk correction and pixel-wise calibration is applied for the LSO detector, whose resolution improves up to 630 ps. In conclusion, the detector setup is suitable for time-resolved background suppression in pulsed clinical particle accelerators. Ongoing tasks are the quantitative comparison with simulations and the test of imaging algorithms. Experiments at proton

Prompt gamma analysis of chlorine in concrete for corrosion study

Energy Technology Data Exchange (ETDEWEB)

Naqvi, A.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)]. E-mail: aanaqvi@kfupm.edu.sa; Nagadi, M.M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Amoudi, O.S.B. [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2006-02-15

Measurement of chlorine in concrete is very important for studying of corrosion of reinforcing steel in concrete. Corrosion of reinforcing steel is primarily ascribed to the penetration of chloride ions to the steel surface. Preventive measures for avoiding concrete structure reinforcement corrosion requires monitoring the chloride ion concentration in concrete so that its concentration does not exceed a threshold limit to initiate reinforcement concrete corrosion. An accelerator based prompt gamma neutron activation analysis (PGNAA) setup has been developed for non-destructive analysis of elemental composition of concrete samples. The setup has been used to measure chlorine concentration in concrete samples over a 1-3 wt% concentration range. Although a strong interference has been observed between the chlorine {gamma}-rays and calcium {gamma}-rays from concrete, the chlorine concentration in concrete samples has been successfully measured using the 1.164 and 7.643 MeV chlorine {gamma}-rays. The experimental data were compared with the results of the Monte Carlo simulations. An excellent agreement has been achieved between the experimental data and results of Monte Carlo simulations. The study has demonstrated the successful use of the accelerator-based PGNAA setup in non-destructive analysis of chlorine in concrete samples.

The Prompt Gamma Neutron Activation Analysis Facility at ICN-Pitesti

International Nuclear Information System (INIS)

Barbos, D.; Paunoiu, C.; Mladin, M.; Cosma, C.

2008-01-01

PGNAA is a very widely applicable technique for determining the presence and amount of many elements simultaneously in samples ranging in size from micrograms to many grams. PGNAA is characterized by its capability for nondestructive multi-elemental analysis and its ability to analyse elements that cannot be determined by INAA. By means of this PGNAA method we are able to increase the performance of INAA method. A facility has been developed at Institute for Nuclear Research-Pitesti so that the unique features of prompt gamma-ray neutron activation analysis can be used to measure trace and major elements in samples. The facility is linked at the radial neutron beam tube at ACPR-TRIGA reactor. During the PGNAA-facility is in use the ACPR reactor will be operated in steady-state mode at 250 KW maximum power. The facility consists of a radial beam-port, external sample position with shielding, and induced prompt gamma-ray counting system.Thermal neutron flux with energy lower than cadmium cut-off at the sample position was measured using thin gold foil is: φ scd = 1.10 6 n/cm 2 /s with a cadmium ratio of:80.The gamma-ray detection system consist of an HpGe detector of 16% efficiency (detector model GC1518) with 1.85 keV resolution capability. The HpGe is mounted with its axis at 90 deg. with respect to the incident neutron beam at distance about 200mm from the sample position. To establish the performance capabilities of the facility, irradiation of pure element or sample compound standards were performed to identify the gama-ray energies from each element and their count rates

TU-FG-BRB-07: GPU-Based Prompt Gamma Ray Imaging From Boron Neutron Capture Therapy

Energy Technology Data Exchange (ETDEWEB)

Kim, S; Suh, T; Yoon, D; Jung, J; Shin, H; Kim, M [The catholic university of Korea, Seoul (Korea, Republic of)

2016-06-15

Purpose: The purpose of this research is to perform the fast reconstruction of a prompt gamma ray image using a graphics processing unit (GPU) computation from boron neutron capture therapy (BNCT) simulations. Methods: To evaluate the accuracy of the reconstructed image, a phantom including four boron uptake regions (BURs) was used in the simulation. After the Monte Carlo simulation of the BNCT, the modified ordered subset expectation maximization reconstruction algorithm using the GPU computation was used to reconstruct the images with fewer projections. The computation times for image reconstruction were compared between the GPU and the central processing unit (CPU). Also, the accuracy of the reconstructed image was evaluated by a receiver operating characteristic (ROC) curve analysis. Results: The image reconstruction time using the GPU was 196 times faster than the conventional reconstruction time using the CPU. For the four BURs, the area under curve values from the ROC curve were 0.6726 (A-region), 0.6890 (B-region), 0.7384 (C-region), and 0.8009 (D-region). Conclusion: The tomographic image using the prompt gamma ray event from the BNCT simulation was acquired using the GPU computation in order to perform a fast reconstruction during treatment. The authors verified the feasibility of the prompt gamma ray reconstruction using the GPU computation for BNCT simulations.

Methodology for Quantitative Analysis of Large Liquid Samples with Prompt Gamma Neutron Activation Analysis using Am-Be Source

International Nuclear Information System (INIS)

Idiri, Z.; Mazrou, H.; Beddek, S.; Amokrane, A.

2009-01-01

An optimized set-up for prompt gamma neutron activation analysis (PGNAA) with Am-Be source is described and used for large liquid samples analysis. A methodology for quantitative analysis is proposed: it consists on normalizing the prompt gamma count rates with thermal neutron flux measurements carried out with He-3 detector and gamma attenuation factors calculated using MCNP-5. The relative and absolute methods are considered. This methodology is then applied to the determination of cadmium in industrial phosphoric acid. The same sample is then analyzed by inductively coupled plasma (ICP) method. Our results are in good agreement with those obtained with ICP method.

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1994-05-01

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

Energies and Yields of Prompt Gamma Rays from Fragments in Slow-Neutron Induced Fission of 235U

Energy Technology Data Exchange (ETDEWEB)

Albinsson, H [Chalmers Univ. of Technology, Goeteborg (SE)

1971-04-15

Measurements were made on the gamma radiation emitted from fission fragments in slow-neutron induced fission of 235U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way it was possible to select various collimator settings and let gamma radiation of different half-lives be enhanced. Gamma-ray energy spectra from these time components were then recorded as function of mass. The spectrum shape differed greatly depending on the half-life of the radiation and the fragment from which it was emitted. The results of the present measurements were discussed in the light of existing fission models, and comparisons were made with prompt gamma-ray and neutron data from other fission experiments

Energies and Yields of Prompt Gamma Rays from Fragments in Slow-Neutron Induced Fission of 235U

International Nuclear Information System (INIS)

Albinsson, H.

1971-04-01

Measurements were made on the gamma radiation emitted from fission fragments in slow-neutron induced fission of 235 U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way it was possible to select various collimator settings and let gamma radiation of different half-lives be enhanced. Gamma-ray energy spectra from these time components were then recorded as function of mass. The spectrum shape differed greatly depending on the half-life of the radiation and the fragment from which it was emitted. The results of the present measurements were discussed in the light of existing fission models, and comparisons were made with prompt gamma-ray and neutron data from other fission experiments

Imaging of heterogeneous materials by prompt gamma-ray neutron activation analysis

International Nuclear Information System (INIS)

Staples, P.; Prettyman, T.; Lestone, J.

1998-01-01

The authors have used a tomographic gamma scanner (TGS) to produce tomographic prompt gamma-ray neutron activation analysis imaging (PGNAA) of heterogeneous matrices. The TGS was modified by the addition of graphite reflectors that contain isotopic neutron sources for sample interrogation. The authors are in the process of developing the analysis methodology necessary for a quantitative assay of large containers of heterogeneous material. This nondestructive analysis (NDA) technique can be used for material characterization and the determination of neutron assay correction factors. The most difficult question to be answered is the determination of the source-to-sample coupling term. To assist in the determination of the coupling term, the authors have obtained images for a range of sample that are very well characterized, such as, homogenous pseudo one-dimensional samples to three-dimensional heterogeneous samples. They then compare the measurements to MCNP calculations. For an accurate quantitative measurement, it is also necessary to determine the sample gamma-ray self attenuation at higher gamma-ray energies, namely pair production should be incorporated into the analysis codes

Implementation of the Prompt Gamma facility in the ININ

International Nuclear Information System (INIS)

Macias B, L.R.; Delfin L, A.; Aguilar H, F.

2002-01-01

The Prompt Gamma Neutron Activation Analysis (PGNAA) technique is based on the reaction of a neutron and an atom emitting gamma radiation in an immediate form and it is used for the elemental identification and characterization. This is a non-destructive technique and presents advantages compared with the X-ray fluorescence analysis technique since it has the advantage of the ability for the neutron penetration which allows a complete analysis in volume of material while the X-ray penetration is not very deep, it is superficial and other advantage of PGNAA is that can detects light elements while by mean of the X-ray fluorescence technique it is not possible. In this work it is shown the implementation of this technique un the National Institute of Nuclear Research (ININ) and the way in which this technique is applied with a radiation source of the TRIGA Mark III reactor from which thermal neutrons were isolated. (Author)

Application of prompt gamma ray analysis to biological samples

Energy Technology Data Exchange (ETDEWEB)

Oura, Yasuji; Nakahara, Hiromichi [Graduate School of Science, Tokyo Metropolitan University, Tokyo (Japan); Enomoto, Shuichi [Radioisotope Technology Division, Cyclotron Center, Institute of Physical and Chemical Research (RIKEN), Wako, Saitama (Japan)

2001-05-01

Prompt {gamma}-ray activation analysis using the internal monostandard method was applied to organs taken from rats. After B, Cd, or Hg was injected into the rats, the content ratios of B/H, Cd/H, and Hg/H were determined in the brain, kidney, liver, bone, and muscle to study their distribution and metabolism. B was distributed in all organs but was metabolized rapidly. Cd slowly accumulated in the liver and kidney throughout the 65 hours study but no Cd was detected in the brain. Hg accumulated mainly in the kidney 3 hrs after the injection. (author)

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.

Interferences in Prompt {gamma} Analysis of corrosive contaminants in concrete

Energy Technology Data Exchange (ETDEWEB)

Naqvi, A.A. [Department of Physics, King Fahd University of Petroleum and Minerals, KFUPM Box 1815, Dhahran-31261 (Saudi Arabia)]. E-mail: aanaqvi@kfupm.edu.sa; Nagadi, M.M. [Department of Physics, King Fahd University of Petroleum and Minerals, KFUPM Box 1815, Dhahran-31261 (Saudi Arabia); Al-Amoudi, O.S.B. [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

2006-12-21

An accelerator-based Prompt Gamma Neutron Activation Analysis (PGNAA) setup has been developed to measure the concentration of corrosive chloride and sulfate contaminants in concrete. The Minimum Detectable Concentration (MDC) limit of chlorine and sulfur in the concrete depends upon the {gamma}-ray used for elemental analysis. For more interfering {gamma}-rays, the MDC limit is higher than that for less interfering {gamma}-rays. The MDC limit of sulfur in concrete measured for the KFUPM PGNAA setup was calculated to be 0.60{+-}0.19 wt%. The MDC limit is equal to the upper limit of sulfur concentration in concrete set by the British Standards. The MDC limit of chlorine in concrete for the KFUPM PGNAA setup, which was calculated for less interfering 1.165 MeV {gamma}-rays, was found to be 0.075{+-}0.025 wt%. The lower limits of the MDC of chlorine in concrete was 73% higher than the limit set by American Concrete Institute. The limit of the MDC can be improved to the desired standard by increasing the intensity of neutron source. For moreinterfering 5.715 and 6.110 MeV chlorine {gamma}-rays the MDC limit was found to be 2-3 times larger than that of 1.165 MeV {gamma}-rays. When normalized to the same intensity of the neutron source, the MDC limits of chlorine and sulfur in concrete from the KFUPM PGNAA setup are better than MDC limits of chlorine in concrete obtained with the {sup 241}Am-Be source-based PGNAA setup. This study has shown that an accelerator-based PGNAA setup can be used in chlorine and sulfur analysis of concrete samples.

Development of an automatic prompt gamma-ray activation analysis system

International Nuclear Information System (INIS)

Osawa, Takahito

2013-01-01

An automatic prompt gamma-ray activation analysis system was developed and installed at the Japan Research Reactor No. 3 Modified (JRR-3M). The main control software, referred to as AutoPGA, was developed using LabVIEW 2011 and the hand-made program can control all functions of the analytical system. The core of the new system is an automatic sample exchanger and measurement system with several additional automatic control functions integrated into the system. Up to fourteen samples can be automatically measured by the system. (author)

Estimation and correction of produced light from prompt gamma photons on luminescence imaging of water for proton therapy dosimetry

Science.gov (United States)

Yabe, Takuya; Komori, Masataka; Toshito, Toshiyuki; Yamaguchi, Mitsutaka; Kawachi, Naoki; Yamamoto, Seiichi

2018-02-01

Although the luminescence images of water during proton-beam irradiation using a cooled charge-coupled device camera showed almost the same ranges of proton beams as those measured by an ionization chamber, the depth profiles showed lower Bragg peak intensities than those measured by an ionization chamber. In addition, a broad optical baseline signal was observed in depths that exceed the depth of the Bragg peak. We hypothesize that this broad baseline signal originates from the interaction of proton-induced prompt gamma photons with water. These prompt gamma photons interact with water to form high-energy Compton electrons, which may cause luminescence or Cherenkov emission from depths exceeding the location of the Bragg peak. To clarify this idea, we measured the luminescence images of water during the irradiations of protons in water with minimized parallax errors, and also simulated the produced light by the interactions of prompt gamma photons with water. We corrected the measured depth profiles of the luminescence images by subtracting the simulated distributions of the produced light by the interactions of prompt gamma photons in water. Corrections were also conducted using the estimated depth profiles of the light of the prompt gamma photons, as obtained from the off-beam areas of the luminescence images of water. With these corrections, we successfully obtained depth profiles that have almost identical distributions as the simulated dose distributions for protons. The percentage relative height of the Bragg peak with corrections to that of the simulation data increased to 94% from 80% without correction. Also, the percentage relative offset heights of the deeper part of the Bragg peak with corrections decreased to 0.2%-0.4% from 4% without correction. These results indicate that the luminescence imaging of water has potential for the dose distribution measurements for proton therapy dosimetry.

Prompt Gamma Radiation from Fragments in the Thermal Fission of {sup 235}U

Energy Technology Data Exchange (ETDEWEB)

Albinsson, H [Chalmers Univ. of Technology, Goteborg (Sweden); Lindow, L [AB Atomenergi, Nykoeping (Sweden)

1970-06-15

Measurements were made on the gamma radiation emitted from fission fragments in slow neutron induced fission of {sup 235}U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way a decay curve was obtained from which the life-time of one of the gamma-emitting states could be estimated. The relative yield of the gamma-rays was determined as a function of mass for different gamma-ray energy portions and two specific time intervals after the fission events. Comparisons were made with data obtained from {sup 252} Cf-fission. Attention is drawn to some features which seem to be the same in {sup 235}U and {sup 252} Cf-fission.

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)

Source Correlated Prompt Neutron Activation Analysis for Material Identification and Localization

Science.gov (United States)

Canion, Bonnie; McConchie, Seth; Landsberger, Sheldon

2017-07-01

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

Burnup determination of power reactor fuel elements by gamma spectrometry; Determination par spectrometrie {gamma} du taux d'irradiation des elements combustibles des reacteurs de puissance

Energy Technology Data Exchange (ETDEWEB)

Robin, M; Jastrzeb, M; Boisliveau, S; Boyer, R; Vidal, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

This report describes a method for determining by {gamma} spectrometry the burn up and the specific power of fuel elements irradiated in power reactors. The energy spectrum of {gamma} rays emitted by fission products is measured by means of a simple equipment using a sodium iodide detector and a multichannel analyzer. In order to extract from the spectrum a quantity proportional to the burn up, it is necessary to: - isolate an activity specific of one emitter,- give the same importance to fissions in uranium and plutonium - take into account the radioactive decay during and after irradiation. One hundred fuel elements were studied and burn up values obtained by {gamma} spectrometry are compared to results given by chemical analyses. Preliminary measurements show that the accuracy of the results is greatly increased by the use of a germanium detector, due to its good resolution. (authors) [French] Ce rapport expose une methode de determination par spectrometrie {gamma} du taux d'irradiation et de la puissance specifique des elements combustibles irradies dans les reacteurs de puissance. Une installation simple utilisant un detecteur d'iodure de sodium et un selecteur multicanaux mesure le spectre en energie du rayonnement {gamma} emis par les produits de fission. Afin d'extraire du spectre une quantite proportionnelle au taux de combustion, il faut: - isoler une activite specifique a un emetteur, - donner la meme importance aux fissions survenues dans l'uranium et le plutonium, - prendre en compte la decroissance radioactive pendant et apres l'irradiation. Les mesures ont porte sur une centaine d'elements combustibles et les taux de combustion obtenus par spectrometrie {gamma} sont compares aux resultats des analyses chimiques. Des mesures preliminaires montrent que l'utilisation d'un detecteur de germanium augmente considerablement la precision des resultats, en raison de son excellente resolution. (auteurs)

Methodology for using prompt gamma activation analysis to measure the binary diffusion coefficient of a gas in a porous medium

International Nuclear Information System (INIS)

Rios Perez, Carlos A.; Biegalski, Steve R.; Deinert, Mark R.

2012-01-01

Highlights: ► Prompt gamma activation analysis is used to study gas diffusion in a porous system. ► Diffusion coefficients are determined using prompt gamma activation analysis. ► Predictions concentrations fit experimental measurements with an R 2 of 0.98. - Abstract: Diffusion plays a critical role in determining the rate at which gases migrate through porous systems. Accurate estimates of diffusion coefficients are essential if gas transport is to be accurately modeled and better techniques are needed that can be used to measure these coefficients non-invasively. Here we present a novel method for using prompt gamma activation analysis to determine the binary diffusion coefficients of a gas in a porous system. Argon diffusion experiments were conducted in a 1 m long, 10 cm diameter, horizontal column packed with a SiO 2 sand. The temporal variation of argon concentration within the system was measured using prompt gamma activation analysis. The binary diffusion coefficient was obtained by comparing the experimental data with the predictions from a numerical model in which the diffusion coefficient was varied until the sum of square errors between experiment and model data was minimized. Predictions of argon concentration using the optimal diffusivity fit experimental measurements with an R 2 of 0.983.

Prompt gamma cold neutron activation analysis applied to biological materials

International Nuclear Information System (INIS)

Rossbach, M.; Hiep, N.T.

1992-01-01

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

A compact neutron beam generator system designed for prompt gamma nuclear activation analysis.

Science.gov (United States)

Ghassoun, J; Mostacci, D

2011-08-01

In this work a compact system was designed for bulk sample analysis using the technique of PGNAA. The system consists of (252)Cf fission neutron source, a moderator/reflector/filter assembly, and a suitable enclosure to delimit the resulting neutron beam. The moderator/reflector/filter arrangement has been optimised to maximise the thermal neutron component useful for samples analysis with a suitably low level of beam contamination. The neutron beam delivered by this compact system is used to irradiate the sample and the prompt gamma rays produced by neutron reactions within the sample elements are detected by appropriate gamma rays detector. Neutron and gamma rays transport calculations have been performed using the Monte Carlo N-Particle transport code (MCNP5). 2010 Elsevier Ltd. All rights reserved.

Imaging of heterogeneous materials by prompt gamma-ray neutron activation analysis

International Nuclear Information System (INIS)

Staples, Parrish; Prettyman, Tom; Lestone, John

1999-01-01

We have used a Tomographic Gamma Scanner (TGS) to produce tomographic Prompt Gamma-Ray Neutron Activation Imaging of heterogeneous matrices [T.H. Prettyman, R.J. Estep, G.A. Sheppard, Trans. Am. Nucl. Soc. 69 (1993) 183-184]. The TGS was modified by the addition of graphite reflectors that contain isotopic neutron sources for sample interrogation. We are in the process of developing the analysis methodology necessary for a quantitative assay of large containers of heterogeneous material. This nondestructive analysis technique can be used for material characterization and the determination of neutron assay correction factors. The most difficult question to be answered is the determination of the source to sample coupling term. To assist in the determination of the coupling term we have obtained images for a range of samples that are very well characterized; such as, homogenous pseudo one-dimensional samples to three-dimensional heterogeneous samples. We then compare the measurements to Monte Carlo N-particle calculations. For an accurate quantitative measurement it is also necessary to determine the sample gamma-ray self attenuation at higher gamma-ray energies, namely pair production should be incorporated into the analysis codes

Measurements of prompt gamma-rays from fast-neutron induced fission with the LICORNE directional neutron source

CERN Document Server

Wilson, J N; Halipre, P; Oberstedt, S; Oberstedt, A

2014-01-01

At the IPN Orsay we have developed a unique, directional, fast neutron source called LICORNE, intended initially to facilitate prompt fission gamma measurements. The ability of the IPN Orsay tandem accelerator to produce intense beams of $^7$Li is exploited to produce quasi-monoenergetic neutrons between 0.5 - 4 MeV using the p($^7$Li,$^7$Be)n inverse reaction. The available fluxes of up to 7 × 10$^7$ neutrons/second/steradian for the thickest hydrogen-rich targets are comparable to similar installations, but with two added advantages: (i) The kinematic focusing produces a natural neutron beam collimation which allows placement of gamma detectors adjacent to the irradiated sample unimpeded by source neutrons. (ii) The background of scattered neutrons in the experimental hall is drastically reduced. The dedicated neutron converter was commissioned in June 2013. Some preliminary results from the first experiment using the LICORNE neutron source at the IPN Orsay are presented. Prompt fission gamma rays from fas...

SU-E-J-142: Prompt Gamma Emission Measurements From a Passively Scattered Proton Beam On Targets Containing 16O, 12C and 14N

Energy Technology Data Exchange (ETDEWEB)

Jeyasugiththan, J [Department of Physics, University of Cape Town, Cape Town (South Africa); Department of Clinical Oncology, Teaching Hospital, Jeffna (Sri Lanka); Peterson, S [Department of Physics, University of Cape Town, Cape Town (South Africa)

2015-06-15

Purpose: To measure the prompt gamma emission from the important elements found in tissue ({sup 16}O,{sup 12}C and {sup 14}N) in a clinical passive-scatter treatment environment. Methods: The targets (composed of water, Perspex, graphite and liquid nitrogen) were irradiated with a 200 MeV passive-scatter proton beam and the discrete prompt gamma energy spectra was detected by a high resolution 2′ × 2′ LaBr. detector. In order to reduce the high level of radiation produced by the beam line elements, the detector was surrounded by 10 cm of lead to attenuate the scattered gamma-rays entering the detector with an extra 5 cm thick layer of lead added along the beam direction. A 10 cm thick collimator with a 5 cm × 10 cm rectangular opening was also used. Results: The prompt gamma peaks at 6.13 MeV and 4.44 MeV were clearly identified as a Result of the inelastic nuclear reaction between the protons and the 16O atoms found in the water target. The 6.13 MeV peak was 5% higher than the peak at 4.44 MeV for the water target. The 4.44 MeV peak was the only identified emission in the prompt gamma energy spectra from the graphite target ({sup 12}C). The expected 2.313 MeV peak form the{sup 14}N (liquid nitrogen target) was identified, but the other expected {sup 14}N peaks could not be resolved. Conclusion: Prompt gamma measurements with a passive-scatter proton beam are possible, but the presence of a high amount of background radiation from the patient final collimator presents a challenge at the treatment isocenter. The prominent prompt gamma peaks at 6.13 MeV and 4.44 MeV were identified from the water, Perspex and graphite targets. The prompt gammas from the liquid nitrogen target were difficult to see, but may not be significant in the in-vivo verification process.

Database of prompt gamma rays from slow neutron capture for elemental analysis

International Nuclear Information System (INIS)

Firestone, R.B.; Choi, H.D.; Lindstrom, R.M.; Molnar, G.L.; Mughabghab, S.F.; Paviotti-Corcuera, R.; Revay, Zs; Trkov, A.; Zhou, C.M.; Zerkin, V.

2004-01-01

The increasing importance of Prompt Gamma-ray Activation Analysis (PGAA) in a broad range of applications is evident, and has been emphasized at many meetings related to this topic (e.g., Technical Consultants' Meeting, Use of neutron beams for low- and medium-flux research reactors: radiography and materials characterizations, IAEA Vienna, 4-7 May 1993, IAEA-TECDOC-837, 1993). Furthermore, an Advisory Group Meeting (AGM) for the Coordination of the Nuclear Structure and Decay Data Evaluators Network has stated that there is a need for a complete and consistent library of cold- and thermal neutron capture gamma ray and cross-section data (AGM held at Budapest,14-18 October 1996, INDC(NDS)-363); this AGM also recommended the organization of an IAEA CRP on the subject. The International Nuclear Data Committee (INDC) is the primary advisory body to the IAEA Nuclear Data Section on their nuclear data programs. At a biennial meeting in 1997, the INDC strongly recommended that the Nuclear Data Section support new measurements and update the database on Neutron-induced Prompt Gamma-ray Activation Analysis (21st INDC meeting, INDC/P(97)-20). As a consequence of the various recommendations, a CRP on ''Development of a Database for Prompt Gamma-ray Neutron Activation Analysis (PGAA)'' was initiated in 1999. Prior to this project, several consultants had defined the scope, objectives and tasks, as approved subsequently by the IAEA. Each CRP participant assumed responsibility for the execution of specific tasks. The results of their and other research work were discussed and approved by the participants in research co-ordination meetings (see Summary reports: INDC(NDS)-411, 2000; INDC(NDS)-424, 2001; and INDC(NDS)-443, 200). PGAA is a non-destructive radioanalytical method, capable of rapid or simultaneous ''in-situ'' multi-element analyses across the entire Periodic Table, from hydrogen to uranium. However, inaccurate and incomplete data were a significant hindrance in the

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)

Stability evaluation and correction of a pulsed neutron generator prompt gamma activation analysis system

Science.gov (United States)

Source output stability is important for accurate measurement in prompt gamma neutron activation. This is especially true when measuring low-concentration elements such as in vivo nitrogen (~2.5% of body weight). We evaluated the stability of the compact DT neutron generator within an in vivo nitrog...

Prompt gamma neutron activation analysis facility at the RA-6 research reactor

International Nuclear Information System (INIS)

Sanchez, F. A.; Calzetta, O

2004-01-01

A prompt gamma neutron activation activation analysis facility was developed at the 500 kw thermal power RA-6 research reactor of the Bariloche Atomic Center, Argentina.This facility consist of a radial beam port with external positioning of the sample.The gamma radiation is reduced by a bismuth filter placed inside the extraction tube and the beam diameter is limited by a set of two collimators up to 5 cm.The neutron flux at the sample position is 7 10 6 n/cm 2 s with a Cadmium ratio of 20/1.The gamma detector is a 50 % efficiency type p HPGe rounded by a NaI(Tl) for Compton suppressioning.The gamma spectra is measured through 0 to 8.5 MeV.The background have counting rate of 350 cps without sample. In this work is shown the efficiency curve, the calculed sensibilities and the lower detection limits for B, Cd, Sm, Gd, H, Cl, Hg, Eu, Ti, Ag, Au, Mo. The RA-6's PGNAA facility is fully working, although the analytic capacity is under improvement [es

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

A Temporal Correlation in Quiescent Gamma-Ray Burst Prompt Emission: Evidence for Prognitor Memory

Science.gov (United States)

Patton, Thomas L.; Giblin, Timothy; Hakkila, Jon E.

2018-06-01

In spite of the insight gained into the nature of the Gamma-Ray Bursts (GRB) from early and late-time X-Ray observations in the Swift era, GRB prompt emission continues to provide clues and new insight into the activity of the central engine. A comprehensive understanding of all emission components observed in GRBs, from the traditional prompt GRB emission to the long lived X-Ray and optical decay super- imposed with late-time flaring activity, currently remains allusive. Using data from the Swift Burst Alert Telescope (BAT), we've identified and measured durations observed in GRBs that exhibit multi-episodic prompt emission behavior. Duration analysis of the burst attributes revealed no significant correlations between emissions and quiet time durations. This variability allows us to extrapolate that the central engine is constantly active.

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-01-01

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

Observations of Short Gamma-Ray Bursts: Prompt Emission and Afterglow

Science.gov (United States)

Berger, Edo

2011-09-01

The study of short gamma-ray bursts has been revolutionized by the discovery of afterglows and host galaxies. In this talk I will review observations of the prompt emission, afterglows, and host galaxies, primarily as they pertain to the nature of the progenitor systems. The bulk of the evidence points to the merger of compact objects (NS-NS or NS-BH) making short GRBs the prime candidate for gravitational wave detections with the next generation detectors. This work is partially supported by funds from NASA (through the Swift and Chandra GO programs) and the NSF through an AAG grant.

Measurement of the Shape of the Optical-IR Spectrum of Prompt Emission from Gamma-Ray Bursts

Science.gov (United States)

Grossan, Bruce; Kistaubayev, M.; Smoot, G.; Scherr, L.

2017-06-01

While the afterglow phase of gamma-ray bursts (GRBs) has been extensively measured, detections of prompt emission (i.e. during bright X-gamma emission) are more limited. Some prompt optical measurements are regularly made, but these are typically in a single wide band, with limited time resolution, and no measurement of spectral shape. Some models predict a synchrotron self-absorption spectral break somewhere in the IR-optical region. Measurement of the absorption frequency would give extensive information on each burst, including the electron Lorentz factor, the radius of emission, and more (Shen & Zhang 2008). Thus far the best prompt observations have been explained invoking a variety of models, but often with a non-unique interpretation. To understand this apparently heterogeneous behavior, and to reduce the number of possible models, it is critical to add data on the optical - IR spectral shape.Long GRB prompt X-gamma emission typically lasts ~40-80 s. The Swift BAT instrument rapidly measures GRB positions to within a few arc minutes and communicates them via the internet within a few seconds. We have measured the time for a fast-moving D=700 mm telescope to point and settle to be less than 9 s anywhere on the observable sky. Therefore, the majority of prompt optical-IR emission can be measured responding to BAT positions with this telescope. In this presentation, we describe our observing and science programs, and give our design for the Burst Simultaneous Three-channel Instrument (BSTI), which uses dichroics to send eparate bands to 3 cameras. Two EMCCD cameras, give high-time resolution in B and V; a third camera with a HgCdTe sensor covers H band, allowing us to study extinguished bursts. For a total exposure time of 10 s, we find a 5 sigma sensitivity of 21.3 and 20.3 mag in B and R for 1" seeing and Kitt Peak sky brightness, much fainter than typical previous prompt detections. We estimate 5 sigma H-band sensitivity for an IR optimized telescope to be

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

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

International Nuclear Information System (INIS)

Rasif Mohd Zain; Hearie Hassan; Roslan Yahya

2015-01-01

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

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)

Decay Curves and Half-Lives of Gamma-Emitting States from a Study of Prompt Fission Gamma Radiation

Energy Technology Data Exchange (ETDEWEB)

Albinsson, H [Chalmers Univ. of Technology, Goeteborg (SE)

1971-04-15

Measurements were made on the time distributions of the prompt gamma radiation emitted from fragments in the thermal-neutron induced fission of 235U. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fragments. In this way decay curves were obtained from which half-lives could be estimated. Time components with half-lives of 7.5, 18 and 60 ps were found and their relative intensities were calculated. Half-lives and associated intensities are in good agreement with earlier data from uranium and californium fission. Problems involved in this type of study are discussed. The collimator technique has proved to be effective for determination of half lives down to less than 10 ps

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.

SU-C-204-01: A Fast Analytical Approach for Prompt Gamma and PET Predictions in a TPS for Proton Range Verification

International Nuclear Information System (INIS)

Kroniger, K; Herzog, M; Landry, G; Dedes, G; Parodi, K; Traneus, E

2015-01-01

Purpose: We describe and demonstrate a fast analytical tool for prompt-gamma emission prediction based on filter functions applied on the depth dose profile. We present the implementation in a treatment planning system (TPS) of the same algorithm for positron emitter distributions. Methods: The prediction of the desired observable is based on the convolution of filter functions with the depth dose profile. For both prompt-gammas and positron emitters, the results of Monte Carlo simulations (MC) are compared with those of the analytical tool. For prompt-gamma emission from inelastic proton-induced reactions, homogeneous and inhomogeneous phantoms alongside with patient data are used as irradiation targets of mono-energetic proton pencil beams. The accuracy of the tool is assessed in terms of the shape of the analytically calculated depth profiles and their absolute yields, compared to MC. For the positron emitters, the method is implemented in a research RayStation TPS and compared to MC predictions. Digital phantoms and patient data are used and positron emitter spatial density distributions are analyzed. Results: Calculated prompt-gamma profiles agree with MC within 3 % in terms of absolute yield and reproduce the correct shape. Based on an arbitrary reference material and by means of 6 filter functions (one per chemical element), profiles in any other material composed of those elements can be predicted. The TPS implemented algorithm is accurate enough to enable, via the analytically calculated positron emitters profiles, detection of range differences between the TPS and MC with errors of the order of 1–2 mm. Conclusion: The proposed analytical method predicts prompt-gamma and positron emitter profiles which generally agree with the distributions obtained by a full MC. The implementation of the tool in a TPS shows that reliable profiles can be obtained directly from the dose calculated by the TPS, without the need of full MC simulation

Characteristics of prompt fission gamma-ray emission - Experimental results and predictions

International Nuclear Information System (INIS)

Oberstedt, Andreas; Billnert, Robert; Oberstedt, Stephan

2014-01-01

Systematics from 2001, describing prompt fission gamma-ray spectra (PFGS) characteristics as function of mass and atomic number of the fissioning system, has been revisited and parameters have been revised based on recent experimental results. Although originally expressed for spontaneous and thermal neutron-induced fission, validity for fast neutrons was assumed and applied to predict PFGS characteristics for the reaction n + 238 U up to incident neutron energies of E n = 20 MeV. The results from this work are in good agreement with corresponding results from both model calculations and experiments. (authors)

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

Yield of Prompt Gamma Radiation in Slow-Neutron Induced Fission of 235U as a Function of the Total Fragment Kinetic Energy

Energy Technology Data Exchange (ETDEWEB)

Albinsson, H [Chalmers Univ. of Technology, Goeteborg (SE)

1971-07-01

Fission gamma radiation yields as functions of the total fragment kinetic energy were obtained for 235U thermal-neutron induced fission. The fragments were detected with silicon surface-barrier detectors and the gamma radiation with a Nal(Tl) scintillator. In some of the measurements mass selection was used so that the gamma radiation could also be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. Fission-neutron and gamma-ray data of previous experiments were used for comparisons of the yields, and estimates were made of the variation of the prompt gamma-ray energy with the total fragment kinetic energy

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...

In vivo prompt gamma activation analysis facility for total body nitrogen and cadmium

International Nuclear Information System (INIS)

Munive, Marco; Solis, Jose; Revilla, Angel

2008-01-01

Full text: Prompt Neutron Activation Analysis (PGNAA) is a technique that could have medical applications, like determination of body's contents of protein and heavy metals in vivo. The in vivo PGNAA facility, contains a neutron source (Cf-252) with safety device, a compartment for animal irradiation, and a gamma rays detecting system based on the NaI(Tl) detector with an analytical software. The prompt gamma rays were emitted after 10 -15 s of the interaction, so they don't produce radioactive waste, and have a characteristics energy for each element, i.e. a strong peak at 2.24 MeV is observed for H. The facility has been used with laboratory mice. Water-filled phantom placed in the neutron beam was used to system calibration. Three study groups of 5 mice each one were selected and were feed with a different diet and the total body nitrogen (TBN) of the mice was monitored with the facility. The diet produced a different TBN for each group. Some mice drunk diluted water with Cl 2 Cd, so the presence of Cd was detected in the mouse. The minimum Cd concentration that the system can detect was 20 ppm. The total dose (neutron and gamma dose was measured from TLDs and simulated by MNCP-4B in the sample compartment during the irradiation time (5 minutes) is less than 2.5 mSv. This total dose is low than the dose from other analytical radiological techniques (25 a 50 mSv). (author)

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)

Monitoring of blood-10B concentration for boron neutron capture therapy using prompt gamma-ray analysis

International Nuclear Information System (INIS)

Raaijmakers, C.P.J.; Konijnenberg, M.W.; Dewit, L.; Mijnheer, B.J.; Haritz, D.; Huiskamp, R.; Philipp, K.; Siefert, A.; Stecher-Rasmussen, F.

1995-01-01

The aim of the present study was to monitor the blood- 10 B concentration of laboratory dogs receiving boron neutron capture therapy, in order to obtain optimal agreement between prescribed and actual dose. A prompt gamma-ray analysis system was developed for this purpose at the High Flux Reactor in Petten. The technique was compared with inductively coupled plasma-atomic emission spectrometry and showed good agreement. A substantial variation in 10 B clearance pattern after administration of borocaptate sodium was found between the different dogs. Consequently, the irradiation commencement was adjusted to the individually determined boron elimination curve. Mean blood- 10 B concentratios during irradiation of 25.8±2.2 μg/g (1 SD, n=18) and 49.3±5.3 μg/g (1 SD, n=17) were obtained for intended concentrations of 25 μg/g and 50 μg/g, respectively. These variations are a factor of two smaller than irradiations performed at a uniform post-infusion irradiation starting time. Such a careful bolld- 10 B monitoring procedure is a prerequisite for accurately obtaining such steep dose-response curves as observed during the dog study. (orig.)

Design and construction of prompt-gamma spectroscopy facility applied to the boron determination; Diseno y construccion de una facilidad de espectrometria prompt-gamma aplicada a la determinacion de boro

Energy Technology Data Exchange (ETDEWEB)

Poblete, Victor; Henriquez, Carlos; Klein, Juan; Navarro, Gustavo [Comision Chilena de Energia Nuclear, Santiago (Chile). Centro de Estudios Nucleares La Reina, Comision Chis Nucleares La Reina, Comision Chi Reina

1997-12-31

A prompt-gamma spectroscopy facility was developed using the south tangential neutron beam of the RECH-1 research reactor for boron determination. The implementation of a thermal neutron beam was performed considering different aspects such as biological protection of working area and the beam collimation for a Ge detector, design and sample holder selection, standards and sample preparation. One ppm of Boron in different samples with counting-rate of 20 minutes and a good accuracy were determined. (author). 5 refs.

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)

Configuration Design of Detector Shielding for Gamma Prompt Analysis

International Nuclear Information System (INIS)

Elin-Nuraini; Darsono; Elisabeth

2000-01-01

Configuration on design of detector shielding for gamma prompt analysishas been performed. The aim of this design is to obtain effective shieldingmaterial and configuration that able to protect the detector for fastneutron. The result shown that detector shielding configuration that obtainedby configuration of water and concrete, would be able to absorb fast neutronup to 99.5 %. The neutron flux that passed through shielding configuration is2.4 x 10 3 n/cm 2 dt, in the detector position of 60 cm (forward neutron beamdirection) on the X axis and 30 cm (side ward neutron beam direction) on theZ axis of target. On this position (60,30) counting result was 104358 for Pbcollimator and 246652 for PVC collimator. From examination result shown thatthe weight of silicon is in order 175 gram. (author)

Database of prompt gamma rays from slow neutron capture forelemental analysis

Energy Technology Data Exchange (ETDEWEB)

Firestone, R.B.; Choi, H.D.; Lindstrom, R.M.; Molnar, G.L.; Mughabghab, S.F.; Paviotti-Corcuera, R.; Revay, Zs; Trkov, A.; Zhou,C.M.; Zerkin, V.

2004-12-31

The increasing importance of Prompt Gamma-ray ActivationAnalysis (PGAA) in a broad range of applications is evident, and has beenemphasized at many meetings related to this topic (e.g., TechnicalConsultants' Meeting, Use of neutron beams for low- andmedium-fluxresearch reactors: radiography and materialscharacterizations, IAEA Vienna, 4-7 May 1993, IAEA-TECDOC-837, 1993).Furthermore, an Advisory Group Meeting (AGM) for the Coordination of theNuclear Structure and Decay Data Evaluators Network has stated that thereis a need for a complete and consistent library of cold- and thermalneutron capture gammaray and cross-section data (AGM held at Budapest,14-18 October 1996, INDC(NDS)-363); this AGM also recommended theorganization of an IAEA CRP on the subject. The International NuclearData Committee (INDC) is the primary advisory body to the IAEA NuclearData Section on their nuclear data programmes. At a biennial meeting in1997, the INDC strongly recommended that the Nuclear Data Section supportnew measurements andupdate the database on Neutron-induced PromptGamma-ray Activation Analysis (21st INDC meeting, INDC/P(97)-20). As aconsequence of the various recommendations, a CRP on "Development of aDatabase for Prompt Gamma-ray Neutron Activation Analysis (PGAA)" wasinitiated in 1999. Prior to this project, several consultants had definedthe scope, objectives and tasks, as approved subsequently by the IAEA.Each CRP participant assumed responsibility for the execution of specifictasks. The results of their and other research work were discussed andapproved by the participants in research co-ordination meetings (seeSummary reports: INDC(NDS)-411, 2000; INDC(NDS)-424, 2001; andINDC(NDS)-443, 200). PGAA is a non-destructive radioanalytical method,capable of rapid or simultaneous "in-situ" multi-element analyses acrossthe entire Periodic Table, from hydrogen to uranium. However, inaccurateand incomplete data were a significant hindrance in the qualitative andquantitative

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 ...

The Design of a Prompt Gamma Neutron Activation Analysis Beam for BNCT Purpose at the TRIGA Mark II Reactor in Pavia

Energy Technology Data Exchange (ETDEWEB)

Stella, S.; Bazani, A.; Ballarini, F.; Bortolussi, S.; Protti, N.; Altieri, S. [Department of Nuclear and Theoretical Physics, University of Pavia (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Section of Pavia (Italy); Bruschi, P. [Department of Nuclear and Theoretical Physics, University of Pavia (Italy)

2011-07-01

In preclinical and clinical Boron Neutron Capture Therapy studies the knowledge of the amount of {sup 10}B in blood and tissues is very important. The boron concentration measurements method used in Pavia (Italy) is based on the charged particles spectrometry of thin tissue cuts irradiated in the Thermal Column of the TRIGA reactor of the University. In order to perform measurements in biological liquids such as blood and urine, or in other tissue that cannot be cut in slices, a Prompt Gamma Neutron Activation Analysis (PGNAA) facility is being designed, which measures {sup 10}B concentration detecting the prompt gamma from boron nuclear capture reaction. At the TRIGA reactor in Pavia, there are four horizontal channels, potentially available for PGNAA. The choice of the suitable channel, and the design of its configuration, were achieved using the Monte Carlo neutron transport code MCNP4c2. To perform the simulations, an input code already validated, describing the reactor structure and the neutron source, was used. The calculations were implemented applying non-analog techniques for the neutron transport, that are necessary to obtain a sufficient statistic in every positions along the channel and especially at its end. The selection of the channel for PGNAA installation was carried out by comparing the simulated fluxes obtained in the different channels at the present configuration. The channel shielded by the core reflector was chosen, because the graphite lowers the fast component of the neutrons, with no need to insert additional material in the facility. The thermal flux at its end is 1.7 x 10{sup 8} n/cm{sup 2} s with thermal-to-total neutron flux ratio around 0.8. Subsequently a bismuth block for gamma radiation shielding and blocks of single crystal sapphire as filter for fast neutron component were inserted in the channel. Other components of the facility that are under study are a collimator and the beam catcher. (author)

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.

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.

Prompt gamma analysis of fly ash, silica fume and Superpozz blended cement concrete specimen

Energy Technology Data Exchange (ETDEWEB)

Naqvi, A.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)], E-mail: aanaqvi@kfupm.edu.sa; Garwan, M.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Maslehuddin, M. [Center for Engineering Research, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Nagadi, M.M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Amoudi, O.S.B. [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Khateeb-ur-Rehman; Raashid, M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2009-09-15

Preventive measures against corrosion of reinforcing steel require making the concrete dense by adding pozzolanic materials, such as fly ash, silica fume, Superpozz, blast furnace slag, etc. to Portland cement. In order to obtain the desired strength and durability of concrete, it is desirable to monitor the concentration of the pozzolan in the blended cement concrete. Addition of pozzolan to blended cement changes the overall concentration of calcium and silicon in the blended cement concrete. The resulting variation in calcium and silicon gamma-ray yield ratio from blended cement concrete has found to have an inverse correlation with concentration of fly ash, silica fume, Superpozz, blast furnace slag in the blended cement concrete. For experimental verification of the correlation, intensities of calcium and silicon prompt gamma-ray due to capture of thermal neutrons in blended cement concrete samples containing 5-80% (by weight of cement) silica fume, fly ash and Superpozz were measured. The gamma-ray intensity ratio was measured from 6.42 MeV gamma-rays from calcium and 4.94 MeV gamma-ray from silicon. The experimentally measured values of calcium to silicon gamma-ray yield ratio in the fly ash, silica fume and Superpozz cement concrete specimens agree very well with the results of the Monte Carlo simulations.

Prompt gamma analysis of fly ash, silica fume and Superpozz blended cement concrete specimen

International Nuclear Information System (INIS)

Naqvi, A.A.; Garwan, M.A.; Maslehuddin, M.; Nagadi, M.M.; Al-Amoudi, O.S.B.; Khateeb-ur-Rehman,; Raashid, M.

2009-01-01

Preventive measures against corrosion of reinforcing steel require making the concrete dense by adding pozzolanic materials, such as fly ash, silica fume, Superpozz, blast furnace slag, etc. to Portland cement. In order to obtain the desired strength and durability of concrete, it is desirable to monitor the concentration of the pozzolan in the blended cement concrete. Addition of pozzolan to blended cement changes the overall concentration of calcium and silicon in the blended cement concrete. The resulting variation in calcium and silicon gamma-ray yield ratio from blended cement concrete has found to have an inverse correlation with concentration of fly ash, silica fume, Superpozz, blast furnace slag in the blended cement concrete. For experimental verification of the correlation, intensities of calcium and silicon prompt gamma-ray due to capture of thermal neutrons in blended cement concrete samples containing 5-80% (by weight of cement) silica fume, fly ash and Superpozz were measured. The gamma-ray intensity ratio was measured from 6.42 MeV gamma-rays from calcium and 4.94 MeV gamma-ray from silicon. The experimentally measured values of calcium to silicon gamma-ray yield ratio in the fly ash, silica fume and Superpozz cement concrete specimens agree very well with the results of the Monte Carlo simulations.

Design and construction of prompt-gamma spectroscopy facility applied to the boron determination

International Nuclear Information System (INIS)

Poblete, Victor; Henriquez, Carlos; Klein, Juan; Navarro, Gustavo

1996-01-01

A prompt-gamma spectroscopy facility was developed using the south tangential neutron beam of the RECH-1 research reactor for boron determination. The implementation of a thermal neutron beam was performed considering different aspects such as biological protection of working area and the beam collimation for a Ge detector, design and sample holder selection, standards and sample preparation. One ppm of Boron in different samples with counting-rate of 20 minutes and a good accuracy were determined. (author)

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

Development and applications of k0 based NAA and prompt gamma-ray NAA methods at BARC

International Nuclear Information System (INIS)

Acharya, R.; Nair, A.G.C.; Sudarshan, K.; Goswami, A.; Reddy, A.V.R.

2008-01-01

A summary of k 0 -based R and D work on neutron activation analysis (NAA), internal mono standard NAA (IM-NAA) and prompt gamma-ray NAA (PGNAA) is presented. The k 0 -based NAA was standardized by characterizing irradiation sites of research reactors, validated using reference materials and applied to samples of different origin. Recently IM-NAA method was developed, validated for small and large size samples and applied for the analysis of large size as well as non-standard geometry samples. Studies on PGNAA included characterization of neutron beam, determinations of detection efficiency and prompt k 0 -factors, and analytical applications. (author)

Monte Carlo simulation of the scattered component of neutron capture prompt gamma-ray analyzer responses

International Nuclear Information System (INIS)

Jin, Y.; Verghese, K.; Gardner, R.P.

1986-01-01

This paper describes a major part of our efforts to simulate the entire spectral response of the neutron capture prompt gamma-ray analyzer for bulk media (or conveyor belt) samples by the Monte Carlo method. This would allow one to use such a model to augment or, in most cases, essentially replace experiments in the calibration and optimum design of these analyzers. In previous work, we simulated the unscattered gamma-ray intensities, but would like to simulate the entire spectral response as we did with the energy-dispersive x-ray fluorescence analyzers. To accomplish this, one must account for the scattered gamma rays as well as the unscattered and one must have available the detector response function to translate the incident gamma-ray spectrum calculated by the Monte Carlo simulation into the detected pulse-height spectrum. We recently completed our work on the germanium detector response function, and the present paper describes our efforts to simulate the entire spectral response by using it with Monte Carlo predicted unscattered and scattered gamma rays

Scientific prospects for spectroscopy of the gamma-ray burst prompt emission with SVOM

Science.gov (United States)

Bernardini, M. G.; Xie, F.; Sizun, P.; Piron, F.; Dong, Y.; Atteia, J.-L.; Antier, S.; Daigne, F.; Godet, O.; Cordier, B.; Wei, J.

2017-10-01

SVOM (Space-based multi-band astronomical Variable Objects Monitor) is a Sino-French space mission dedicated to the study of Gamma-Ray Bursts (GRBs) in the next decade, capable to detect and localise the GRB emission, and to follow its evolution in the high-energy and X-ray domains, and in the visible and NIR bands. The satellite carries two wide-field high-energy instruments: a coded-mask gamma-ray imager (ECLAIRs; 4-150 keV), and a gamma-ray spectrometer (GRM; 15-5500 keV) that, together, will characterise the GRB prompt emission spectrum over a wide energy range. In this paper we describe the performances of the ECLAIRs and GRM system with different populations of GRBs from existing catalogues, from the classical ones to those with a possible thermal component superimposed to their non-thermal emission. The combination of ECLAIRs and the GRM will provide new insights also on other GRB properties, as for example the spectral characterisation of the subclass of short GRBs showing an extended emission after the initial spike.

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)

MO-FG-CAMPUS-JeP1-01: Prompt Gamma Imaging with a Multi-Knife-Edge Slit Collimator: Evaluation for Use in Proton Beam Range Verification

Energy Technology Data Exchange (ETDEWEB)

Ready, J [UC Berkeley, Berkeley, CA (United States); Negut, V; Mihailescu, L [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Vetter, K [UC Berkeley, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

2016-06-15

Purpose: To evaluate and characterize a multi-slit collimated imaging system for use in prompt gamma range verification of proton therapy. Methods: Acrylic (PMMA) targets were irradiated with a 50 MeV proton beam. With the collimator placed 13 cm from the beam axis, photons of energy from 2–7 MeV were measured. Image reconstruction provided 2-dimensional distribution of gamma rays. Estimated Bragg peak location was compared with 1-dimensional profiles of photon images. Shifts in Bragg peak were simulated by physically moving the targets in 1 mm increments. Results: The imaging system measured prompt gamma emissions resulting from a 50 MeV proton beam, at currents up to 2 nA, incident on a PMMA target. Overall system detection efficiency was approximately 2.6×10{sup −5} gamma/proton. With delivery of 1×10{sup 11} protons, shifts of 1 mm in the target location were detected in 2D prompt gamma images and 1D profiles. With delivery of 1×10{sup 8} protons, shifts of approximately 3 mm were detectable. Conclusion: This work has characterized the performance of a prototype multi-slit collimated imaging system. The system can produce 2D images of prompt gamma distributions and detect shifts in Bragg peak location down to 1 mm. These results encourage further development and optimization of the system for clinical proton beam applications. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number: DENA0000979 through the Nuclear Science and Security Consortium.

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)

Progress towards a semiconductor Compton camera for prompt gamma imaging during proton beam therapy for range and dose verification

Science.gov (United States)

Gutierrez, A.; Baker, C.; Boston, H.; Chung, S.; Judson, D. S.; Kacperek, A.; Le Crom, B.; Moss, R.; Royle, G.; Speller, R.; Boston, A. J.

2018-01-01

The main objective of this work is to test a new semiconductor Compton camera for prompt gamma imaging. Our device is composed of three active layers: a Si(Li) detector as a scatterer and two high purity Germanium detectors as absorbers of high-energy gamma rays. We performed Monte Carlo simulations using the Geant4 toolkit to characterise the expected gamma field during proton beam therapy and have made experimental measurements of the gamma spectrum with a 60 MeV passive scattering beam irradiating a phantom. In this proceeding, we describe the status of the Compton camera and present the first preliminary measurements with radioactive sources and their corresponding reconstructed images.

SU-F-J-208: Prompt Gamma Imaging-Based Prediction of Bragg Peak Position for Realistic Treatment Error Scenarios

Energy Technology Data Exchange (ETDEWEB)

Xing, Y; Macq, B; Bondar, L [Universite catholique de Louvain, Louvain-la-Neuve (Belgium); Janssens, G [IBA, Louvain-la-Neuve (Belgium)

2016-06-15

Purpose: To quantify the accuracy in predicting the Bragg peak position using simulated in-room measurements of prompt gamma (PG) emissions for realistic treatment error scenarios that combine several sources of errors. Methods: Prompt gamma measurements by a knife-edge slit camera were simulated using an experimentally validated analytical simulation tool. Simulations were performed, for 143 treatment error scenarios, on an anthropomorphic phantom and a pencil beam scanning plan for nasal cavity. Three types of errors were considered: translation along each axis, rotation around each axis, and CT-calibration errors with magnitude ranging respectively, between −3 and 3 mm, −5 and 5 degrees, and between −5 and +5%. We investigated the correlation between the Bragg peak (BP) shift and the horizontal shift of PG profiles. The shifts were calculated between the planned (reference) position and the position by the error scenario. The prediction error for one spot was calculated as the absolute difference between the PG profile shift and the BP shift. Results: The PG shift was significantly and strongly correlated with the BP shift for 92% of the cases (p<0.0001, Pearson correlation coefficient R>0.8). Moderate but significant correlations were obtained for all cases that considered only CT-calibration errors and for 1 case that combined translation and CT-errors (p<0.0001, R ranged between 0.61 and 0.8). The average prediction errors for the simulated scenarios ranged between 0.08±0.07 and 1.67±1.3 mm (grand mean 0.66±0.76 mm). The prediction error was moderately correlated with the value of the BP shift (p=0, R=0.64). For the simulated scenarios the average BP shift ranged between −8±6.5 mm and 3±1.1 mm. Scenarios that considered combinations of the largest treatment errors were associated with large BP shifts. Conclusion: Simulations of in-room measurements demonstrate that prompt gamma profiles provide reliable estimation of the Bragg peak position for

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

EM reconstruction of dual isotope PET using staggered injections and prompt gamma positron emitters

International Nuclear Information System (INIS)

Andreyev, Andriy; Sitek, Arkadiusz; Celler, Anna

2014-01-01

Purpose: The aim of dual isotope positron emission tomography (DIPET) is to create two separate images of two coinjected PET radiotracers. DIPET shortens the duration of the study, reduces patient discomfort, and produces perfectly coregistered images compared to the case when two radiotracers would be imaged independently (sequential PET studies). Reconstruction of data from such simultaneous acquisition of two PET radiotracers is difficult because positron decay of any isotope creates only 511 keV photons; therefore, the isotopes cannot be differentiated based on the detected energy. Methods: Recently, the authors have proposed a DIPET technique that uses a combination of radiotracer A which is a pure positron emitter (such as 18 F or 11 C) and radiotracer B in which positron decay is accompanied by the emission of a high-energy (HE) prompt gamma (such as 38 K or 60 Cu). Events that are detected as triple coincidences of HE gammas with the corresponding two 511 keV photons allow the authors to identify the lines-of-response (LORs) of isotope B. These LORs are used to separate the two intertwined distributions, using a dedicated image reconstruction algorithm. In this work the authors propose a new version of the DIPET EM-based reconstruction algorithm that allows the authors to include an additional, independent estimate of radiotracer A distribution which may be obtained if radioisotopes are administered using a staggered injections method. In this work the method is tested on simple simulations of static PET acquisitions. Results: The authors’ experiments performed using Monte-Carlo simulations with static acquisitions demonstrate that the combined method provides better results (crosstalk errors decrease by up to 50%) than the positron-gamma DIPET method or staggered injections alone. Conclusions: The authors demonstrate that the authors’ new EM algorithm which combines information from triple coincidences with prompt gammas and staggered injections

EM reconstruction of dual isotope PET using staggered injections and prompt gamma positron emitters

Energy Technology Data Exchange (ETDEWEB)

Andreyev, Andriy, E-mail: andriy.andreyev-1@philips.com [Philips Healthcare, Highland Heights, Ohio 44143 (United States); Sitek, Arkadiusz [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Celler, Anna [Department of Radiology, University of British Columbia, Vancouver V5Z 1M9 (Canada)

2014-02-15

Purpose: The aim of dual isotope positron emission tomography (DIPET) is to create two separate images of two coinjected PET radiotracers. DIPET shortens the duration of the study, reduces patient discomfort, and produces perfectly coregistered images compared to the case when two radiotracers would be imaged independently (sequential PET studies). Reconstruction of data from such simultaneous acquisition of two PET radiotracers is difficult because positron decay of any isotope creates only 511 keV photons; therefore, the isotopes cannot be differentiated based on the detected energy. Methods: Recently, the authors have proposed a DIPET technique that uses a combination of radiotracer A which is a pure positron emitter (such as{sup 18}F or {sup 11}C) and radiotracer B in which positron decay is accompanied by the emission of a high-energy (HE) prompt gamma (such as {sup 38}K or {sup 60}Cu). Events that are detected as triple coincidences of HE gammas with the corresponding two 511 keV photons allow the authors to identify the lines-of-response (LORs) of isotope B. These LORs are used to separate the two intertwined distributions, using a dedicated image reconstruction algorithm. In this work the authors propose a new version of the DIPET EM-based reconstruction algorithm that allows the authors to include an additional, independent estimate of radiotracer A distribution which may be obtained if radioisotopes are administered using a staggered injections method. In this work the method is tested on simple simulations of static PET acquisitions. Results: The authors’ experiments performed using Monte-Carlo simulations with static acquisitions demonstrate that the combined method provides better results (crosstalk errors decrease by up to 50%) than the positron-gamma DIPET method or staggered injections alone. Conclusions: The authors demonstrate that the authors’ new EM algorithm which combines information from triple coincidences with prompt gammas and

Determination of contaminants in rare earth materials by prompt gamma activation analysis (PGAA)

International Nuclear Information System (INIS)

Perry, D.L.; English, G.A.; Firestone, R.B.; Molnar, G.L.; Revay, Zs.

2005-01-01

Prompt gamma activation analysis (PGAA) has been used to detect and quantify impurities in the analyses of rare earth (RE) oxides. The analytical results are discussed with respect to the importance of having a thorough identification and contaminant elements in these compounds regarding the function of the materials in their various applications. Also, the importance of using PGAA to analyze materials in support of other physico-chemical studies of the materials is discussed, including the study of extremely low concentrations of ions - such as the rare earth ions themselves - in bulk material matrices. (author)

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

International Nuclear Information System (INIS)

Chien Chung; Jiunnhsing Chao

1991-01-01

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

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)

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.

Body composition to climate change studies - the many facets of neutron induced prompt gamma-ray analysis

International Nuclear Information System (INIS)

Mitra, S.

2008-01-01

In-vivo body composition analysis of humans and animals and in-situ analysis of soil using fast neutron inelastic scattering and thermal neutron capture induced prompt-gamma rays have been described. By measuring carbon (C), nitrogen (N) and oxygen (O), protein, fat and water are determined. C determination in soil has become important for understanding below ground carbon sequestration process in the light of climate change studies. Various neutron sources ranging from radio isotopic to compact 14 MeV neutron generators employing the associated particle neutron time-of-flight technique or micro-second pulsing were implemented. Gamma spectroscopy using recently developed digital multi-channel analyzers has also been described

Body composition to climate change studies - the many facets of neutron induced prompt gamma-ray analysis

Energy Technology Data Exchange (ETDEWEB)

Mitra,S.

2008-11-17

In-vivo body composition analysis of humans and animals and in-situ analysis of soil using fast neutron inelastic scattering and thermal neutron capture induced prompt-gamma rays have been described. By measuring carbon (C), nitrogen (N) and oxygen (O), protein, fat and water are determined. C determination in soil has become important for understanding below ground carbon sequestration process in the light of climate change studies. Various neutron sources ranging from radio isotopic to compact 14 MeV neutron generators employing the associated particle neutron time-of-flight technique or micro-second pulsing were implemented. Gamma spectroscopy using recently developed digital multi-channel analyzers has also been described.

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

The 3D tomographic image reconstruction software for prompt-gamma measurement of the boron neutron capture therapy

International Nuclear Information System (INIS)

Morozov, Boris; Auterinen, Iiro; Kotiluoto, Petri; Kortesniemi, Mika

2006-01-01

A tomographic imaging system based on the spatial distribution measurement of the neutron capture reaction during Boron Neutron Capture Therapy (BNCT) would be very useful for clinical purpose. Using gamma-detectors in a 2D-panel, boron neutron capture and hydrogen neutron capture gamma-rays emitted by the neutron irradiated region can be detected, and an image of the neutron capture events can be reconstructed. A 3D reconstruction software package has been written to support the development of a 3D prompt-gamma tomographic system. The package consists of three independent modules: phantom generation, reconstruction and evaluation modules. The reconstruction modules are based on algebraic approach of the iterative reconstruction algorithm (ART), and on the maximum likelihood estimation method (ML-EM). In addition to that, two subsets of the ART, the simultaneous iterative reconstruction technique (SIRT) and the component averaging algorithms (CAV) have been included to the package employing parallel codes for multiprocessor architecture. All implemented algorithms use two different field functions for the reconstruction of the region. One is traditional voxel function, another is, so called, blob function, smooth spherically symmetric generalized Kaiser-Bessel function. The generation module provides the phantom and projections with background by tracing the prompt gamma-rays for a given scanner geometry. The evaluation module makes statistical comparisons between the generated and reconstructed images, and provides figure-of-merit (FOM) values for the applied reconstruction algorithms. The package has been written in C language and tested under Linux and Windows platforms. The simple graphical user interface (GUI) is used for command execution and visualization purposed. (author)

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.

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

Science.gov (United States)

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

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

In vivo Prompt Gamma Neutron Activation Analysis Facility for Total Body Nitrogen and Cd

International Nuclear Information System (INIS)

Munive, Marco; Revilla, Angel; Solis, Jose L.

2007-01-01

A Prompt Gamma Neutron Activation Analysis (PGNAA) system has been designed and constructed to measure the total body nitrogen and Cd for in vivo studies. An aqueous solution of KNO 3 was used as phantom for system calibration. The facility has been used to monitor total body nitrogen (TBN) of mice and found that is related to their diet. Some mice swallowed diluted water with Cl 2 Cd, and the presence of Cd was detected in the animals. The minimum Cd concentration that the system can detect was 20 ppm

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

THERMAL EMISSION IN THE EARLY X-RAY AFTERGLOWS OF GAMMA-RAY BURSTS: FOLLOWING THE PROMPT PHASE TO LATE TIMES

Energy Technology Data Exchange (ETDEWEB)

Friis, Mette [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavik (Iceland); Watson, Darach, E-mail: mef4@hi.is, E-mail: darach@dark-cosmology.dk [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark)

2013-07-01

Thermal radiation, peaking in soft X-rays, has now been detected in a handful of gamma-ray burst (GRB) afterglows and has to date been interpreted as shock break-out of the GRB's progenitor star. We present a search for thermal emission in the early X-ray afterglows of a sample of Swift bursts selected by their brightness in X-rays at early times. We identify a clear thermal component in eight GRBs and track the evolution. We show that at least some of the emission must come from highly relativistic material since two show an apparent super-luminal expansion of the thermal component. Furthermore, we determine very large luminosities and high temperatures for many of the components-too high to originate in a supernova shock break-out. Instead, we suggest that the component may be modeled as late photospheric emission from the jet, linking it to the apparently thermal component observed in the prompt emission of some GRBs at gamma-ray and hard X-ray energies. By comparing the parameters from the prompt emission and the early afterglow emission, we find that the results are compatible with the interpretation that we are observing the prompt quasi-thermal emission component in soft X-rays at a later point in its evolution.

Measurement of Prompt Photon Cross Sections in Photoproduction at HERA

CERN Document Server

Aktas, A.; Anthonis, T.; Asmone, A.; Babaev, A.; Backovic, S.; Bahr, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, Ch.; Berger, N.; Berndt, T.; Bizot, J.C.; Bohme, J.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brisson, V.; Broker, H.-B.; Brown, D.P.; Bruncko, D.; Busser, F.W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Caron, S.; Cassol-Brunner, F.; Cerny, K.; Chekelian, V.; Collard, C.; Contreras, J.G.; Coppens, Y.R.; Coughlan, J.A.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; Delcourt, B.; Demirchyan, R.; De Roeck, A.; Desch, K.; De Wolf, E.A.; Diaconu, C.; Dingfelder, J.; Dodonov, V.; Dubak, A.; Duprel, C.; Eckerlin, Guenter; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Ellerbrock, M.; Elsen, E.; Erdmann, M.; Erdmann, W.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Fleischer, M.; Fleischmann, P.; Fleming, Y.H.; Flucke, G.; Flugge, G.; Fomenko, A.; Foresti, I.; Formanek, J.; Franke, G.; Frising, G.; Gabathuler, E.; Gabathuler, K.; Garutti, E.; Garvey, J.; Gayler, J.; Gerhards, R.; Gerlich, C.; Ghazaryan, Samvel; Goerlich, L.; Gogitidze, N.; Gorbounov, S.; Grab, C.; Grassler, H.; Greenshaw, T.; Gregori, M.; Grindhammer, Guenter; Gwilliam, C.; Haidt, D.; Hajduk, L.; Haller, J.; Hansson, M.; Heinzelmann, G.; Henderson, R.C.W.; Henschel, H.; Henshaw, O.; Heremans, R.; Herrera, G.; Herynek, I.; Heuer, R.-D.; Hildebrandt, M.; Hiller, K.H.; Hladky, J.; Hoting, P.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jung, H.; Kant, D.; Kapichine, M.; Karlsson, M.; Katzy, J.; Keller, N.; Kennedy, J.; Kenyon, I.R.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Kluge, T.; Knies, G.; Knutsson, A.; Koblitz, B.; Korbel, V.; Kostka, P.; Koutouev, R.; Kropivnitskaya, A.; Kroseberg, J.; Kuckens, J.; Kuhr, T.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Laycock, P.; Lebedev, A.; Leiner, B.; Lemrani, R.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; List, B.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lueders, H.; Luke, D.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marks, J.; Marshall, R.; Martisikova, M.; Martyn, H.-U.; Maxfield, S.J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Michine, S.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morozov, I.; Morris, J.V.; Mozer, Matthias Ulrich; Muller, K.; Murin, P.; Nagovizin, V.; Naroska, B.; Naumann, J.; Naumann, Th.; Newman, Paul R.; Niebuhr, C.; Nikiforov, A.; Nikitin, D.; Nowak, G.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J.E.; Ossoskov, G.; Ozerov, D.; Pascaud, C.; Patel, G.D.; Peez, M.; Perez, E.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Placakyte, R.; Poschl, R.; Portheault, B.; Povh, B.; Raicevic, N.; Ratiani, Z.; Reimer, P.; Reisert, B.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Rybicki, K.; Sankey, D.P.C.; Sauvan, E.; Schatzel, S.; Scheins, J.; Schilling, F.-P.; Schleper, P.; Schmidt, S.; Schmitt, S.; Schneider, M.; Schoeffel, L.; Schoning, A.; Schroder, V.; Schultz-Coulon, H.-C.; Schwanenberger, C.; Sedlak, K.; Sefkow, F.; Sheviakov, I.; Shtarkov, L.N.; Sirois, Y.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Spitzer, H.; Stamen, R.; Stella, B.; Stiewe, J.; Strauch, I.; Straumann, U.; Tchoulakov, V.; Thompson, Graham; Thompson, P.D.; Tomasz, F.; Traynor, D.; Truoel, Peter; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Uraev, A.; Urban, Marcel; Usik, A.; Utkin, D.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vest, A.; Vinokurova, S.; Volchinski, V.; Wacker, K.; Wagner, J.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Werner, N.; Wessels, M.; Wessling, B.; Winter, G.-G.; Wissing, Ch.; Woehrling, E.-E.; Wolf, R.; Wunsch, E.; Xella, S.; Yan, W.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zohrabyan, H.; Zomer, F.

2004-01-01

Results are presented on the photoproduction of isolated prompt photons, inclusively and associated with jets, in the gamma p center of mass energy range 142 4.5 GeV. They are measured differentially as a function of E_T^gamma, E_T^jet, the pseudorapidities eta^gamma and eta^jet and estimators of the momentum fractions x_gamma and x_p of the incident photon and proton carried by the constituents participating in the hard process. In order to further investigate the underlying dynamics, the angular correlation between the prompt photon and the jet in the transverse plane is studied. Predictions by perturbative QCD calculations in next to leading order are about 30% below the inclusive prompt photon data after corrections for hadronisation and multiple interactions, but are in reasonable agreement with the results for prompt photons associated with jets. Comparisons with the predictions of the event generators PYTHIA and HERWIG are also presented.

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

The Prompt Gamma-Ray, Prompt Electron and Prompt X-Ray Spectra Associated with Fission Fragments of Specific Mass; Spectres de Rayons Gamma Instantanes, d'Electrons Instantanes et de Rayons X Instantanes Associes a des Fragments de Fission de Masse Donnee; 041c 0413 041d 041e 0414 ; Espectros de Rayos Gamma. Electrones y Rayos X Inmediatos, Vinculados a Fragmentos de Fision de Masa Determinada

Energy Technology Data Exchange (ETDEWEB)

Bowman, H. R.; Thompson, S. G.; Watson, R. L.; Kapoor, S. S.; Rasmussen, J. O. [Lawrence Radiation Laboratory, University of California, Berkeley, CA (United States)

1965-07-15

Well-defined prompt gamma-rays, prompt-conversion elections and prompt K-X-rays have been observed in coincidence with moving fission fragments of Cf{sup 252}. In a few cases, the masses and charges of the nuclei emitting the gamma-rays and conversion electrons have been identified. The gamma-ray, prompt-electron and prompt X-ray energies as well as the two fission fragments energies were measured with high-resolution solid-state detectors. The masses of the fragments were deduced from their energies, and the nuclear charges were determined by measuring the K-X - ray energies associated with different masses. The magnitude and sign of the Doppler shift in gamma-ray energy allowed assignment of the gamma-ray lines to single members of fragment pairs. The Doppler shift also provides an independent measure of the fragment velocity and hence the fragment mass after neutron emission. The results of the X-ray measurements are consistent with the view that the majority of the prompt X-rays emitted during the spontaneous fission of Cf{sup 252} are the result of internal conversion during the de-excitation of low-energy collective states of the primary fission fragments. Apart from the specific results discussed above, the most important consequence of these experiments has been the demonstration that it is possible to study the properties of individual fission fragments, as identified by their characteristic radiations, rather than studying the properties of an average fission fragment with an average mass and charge. The consequences of this advance in the technique of studying fission fragments ate being explored. (author) [French] Des rayons gamma instantanes, des electrons de conversions instantanes et des rayons X K instantanes bien definis ont ete observes en coincidences avec des fragments de fission de {sup 252}Cf en mouvement. Dans un petit nombre de cas' Les masses, et charges des noyaux emettant les rayons gamma et les electrons de conversion ont ete identifiees

Prompt Gamma Activation Analysis (PGAA): Technique of choice for nondestructive bulk analysis of returned comet samples

International Nuclear Information System (INIS)

Lindstrom, D.J.; Lindstrom, R.M.

1989-01-01

Prompt gamma activation analysis (PGAA) is a well-developed analytical technique. The technique involves irradiation of samples in an external neutron beam from a nuclear reactor, with simultaneous counting of gamma rays produced in the sample by neutron capture. Capture of neutrons leads to excited nuclei which decay immediately with the emission of energetic gamma rays to the ground state. PGAA has several advantages over other techniques for the analysis of cometary materials: (1) It is nondestructive; (2) It can be used to determine abundances of a wide variety of elements, including most major and minor elements (Na, Mg, Al, Si, P, K, Ca, Ti, Cr, Mn, Fe, Co, Ni), volatiles (H, C, N, F, Cl, S), and some trace elements (those with high neutron capture cross sections, including B, Cd, Nd, Sm, and Gd); and (3) It is a true bulk analysis technique. Recent developments should improve the technique's sensitivity and accuracy considerably

Performance characteristics of a prompt gamma-ray activation analysis (PGAA) system equipped with a new compact D-D neutron generator

Energy Technology Data Exchange (ETDEWEB)

Park, Yong Joon; Song, Byung Chul; Im, Hee-Jung [Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, Dukjin-dong 150-1, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Kim, Jong-Yun [Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, Dukjin-dong 150-1, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)], E-mail: kjy@kaeri.re.kr

2009-07-21

A new prompt gamma-ray activation analysis (PGAA) system equipped with a compact deuterium-deuterium (D-D) neutron generator has been developed for fast detection of explosives and chemical warfare agents. The PGAA system was built based on a fully high-voltage-shielded, axial D-D neutron generator with a radio frequency (RF)-driven ion source. The ionic current of the compact neutron generator was determined as a function of the acceleration voltage at various RF powers. Monoenergetic neutrons (2.45 MeV) with a neutron yield of >1x10{sup 7} n/s were obtained at a deuterium pressure of 8.0 mTorr, an acceleration voltage of 80 kV, and an RF power of 1.1 kW. The performance of the PGAA system was examined by studying the dependence of a prompt gamma-ray count rate on crucial operating parameters.

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...

Constraints on millisecond magnetars as the engines of prompt emission in gamma-ray bursts

Science.gov (United States)

Beniamini, Paz; Giannios, Dimitrios; Metzger, Brian D.

2017-12-01

We examine millisecond magnetars as central engines of gamma-ray bursts' (GRBs) prompt emission. Using the protomagnetar wind model of Metzger et al., we estimate the temporal evolution of the magnetization and power injection at the base of the GRB jet and apply these to different prompt emission models to make predictions for the GRB energetics, spectra and light curves. We investigate both shock and magnetic reconnection models for the particle acceleration, as well as the effects of energy dissipation across optically thick and thin regions of the jet. The magnetization at the base of the jet, σ0, is the main parameter driving the GRB evolution in the magnetar model and the emission is typically released for 100 ≲σ0 ≲3000. Given the rapid increase in σ0 as the protomagnetar cools and its neutrino-driven mass loss subsides, the GRB duration is typically limited to ≲100 s. This low baryon loading at late times challenges magnetar models for ultralong GRBs, though black hole models likely run into similar difficulties without substantial entrainment from the jet walls. The maximum radiated gamma-ray energy is ≲5 × 1051 erg, significantly less than the magnetar's total initial rotational energy and in strong tension with the high end of the observed GRB energy distribution. However, the gradual magnetic dissipation model applied to a magnetar central engine, naturally explains several key observables of typical GRBs, including energetics, durations, stable peak energies, spectral slopes and a hard to soft evolution during the burst.

Prompt nuclear analysis bibliography 1976

International Nuclear Information System (INIS)

Bird, J.R.; Campbell, B.L.; Cawley, R.J.

1978-05-01

A prompt nuclear analysis bibliography published in 1974 has been updated to include literature up to the end of 1976. The number of publications has more than doubled since mid-1973. The bibliography is now operated as a computer file and searches can be made on key words and parameters. Tables of references are given for each of the categories: backscattering, ion-ion, ion-gamma, ion-neutron, neutron-gamma, neutron-neutron and gamma-ray-induced reactions

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)

Prompt gamma-ray analysis using JRR-3M cold and thermal neutron guide beams

International Nuclear Information System (INIS)

Yonezawa, C.; Haji Wood, A.K.; Magara, M.; Hoshi, M.; Tachikawa, E.; Sawahata, H.; Ito, Y.

1993-01-01

A permanent and stand-alone neutron-induced prompt gamma-ray analysis (PGA) system, usable at both cold and thermal neutron beam guides of JRR-3M has been constructed. Neutron flux at the sample positions were 1.4x10 8 and 2.4x10 7 n cm -2 s -1 for the cold and thermal neutrons, respectively. The γ-ray spectrometer is equipped to acquire three modes of spectra simultaneously: single mode, Compton suppression mode and pair mode, in an energy range up to 12 MeV. Owing to the cold neutron guide beam and the low γ-ray background system, analytical sensitivities and detection limits better than those in other PGA systems have been achieved. Analytical sensitivity and detection limit for 73 elements were measured. Boron, Gd, Sm and Cd are the most sensitive elements with detection limits down to 1 to 10 ng. For some elements such as F, Al, V, Eu and Hf, decay γ-rays are more sensitive compared to their respective prompt γ-ray. Analytical sensitivity of several heavy elements through detection of characteristic X-rays was higher than that through the prompt γ-ray detection. Analytical applicability of some sensitive elements such as B, H, Gd and Sm were examined. Isotopic analysis of Ni and Si were also examined. (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

On neutron activation analysis with γγ coincidence spectrometry

International Nuclear Information System (INIS)

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

2017-01-01

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

Determination of 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)

Development of a technique using MCNPX code for determination of nitrogen content of explosive materials using prompt gamma neutron activation analysis method

Energy Technology Data Exchange (ETDEWEB)

Nasrabadi, M.N., E-mail: mnnasrabadi@ast.ui.ac.ir [Department of Nuclear Engineering, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Bakhshi, F.; Jalali, M.; Mohammadi, A. [Department of Nuclear Engineering, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of)

2011-12-11

Nuclear-based explosive detection methods can detect explosives by identifying their elemental components, especially nitrogen. Thermal neutron capture reactions have been used for detecting prompt gamma 10.8 MeV following radioactive neutron capture by {sup 14}N nuclei. We aimed to study the feasibility of using field-portable prompt gamma neutron activation analysis (PGNAA) along with improved nuclear equipment to detect and identify explosives, illicit substances or landmines. A {sup 252}Cf radio-isotopic source was embedded in a cylinder made of high-density polyethylene (HDPE) and the cylinder was then placed in another cylindrical container filled with water. Measurements were performed on high nitrogen content compounds such as melamine (C{sub 3}H{sub 6}N{sub 6}). Melamine powder in a HDPE bottle was placed underneath the vessel containing water and the neutron source. Gamma rays were detected using two NaI(Tl) crystals. The results were simulated with MCNP4c code calculations. The theoretical calculations and experimental measurements were in good agreement indicating that this method can be used for detection of explosives and illicit drugs.

Gamma-ray measurements for uranium enrichment standards

International Nuclear Information System (INIS)

Reilly, T.D.

1979-01-01

The gamma-ray spectroscopic measurement of uranium enrichment is one of the most widely used nondestructive analysis techniques. A study has been started of the precision and accuracy achievable with this technique and the physical parameters which affect it. The study was prompted by questions raised during the ongoing ESARDA-NBS experiment to produce uranium oxide reference counting materials for the technique. Results reported using a high-quality Ge(Li) spectrometer system show reproducibility comparable to that attainable with mass spectrometry

Prompt gamma-ray activation analysis for certification of sulfur in fuel oil SRMs

International Nuclear Information System (INIS)

Paul, R.L.

2017-01-01

A combination of cold neutron prompt gamma-ray activation analysis (CNPGAA) and thermal neutron (TN) PGAA was used to determine sulfur in fuel oils to develop a method to provide values for certification. CNPGAA was used to measure S/H mass ratios, and TNPGAA to measure hydrogen mass fractions. Measurements were combined to determine sulfur mass fractions (with expanded uncertainties) of 2.159 ± 0.072 % for SRM 1622e, 0.7066 ± 0.0120 % for SRM 1619b, and 0.1266 ± 0.0030 % for SRM 1617b, in agreement with certified values. The results validate the method as suitable for certification of sulfur at mass fractions ≥0.1 %. (author)

The development of the prompt system of gamma radiation monitoring in FR Yugoslavia

International Nuclear Information System (INIS)

Orlic, M.; Pavlovic, R.; Pavlovic, S.

1996-01-01

The needs for and characteriztics of the prompt system of gamma radiation monitoring are analyzed. The basic structure of the new system, based on the PC computer is presented. The system consists of the central unit and a number of field stations connected via telephone lines. GM counter is used as a detector. The software is written in visual basic. The system is capable of performing a variety of tasks: dose rate measurement (analogue and digital), graphical presentation of the results in the given period of time, data base formation and management, data transmission and preparing reports. The basic characteriztics of hardware and software of the system, performance specifications and future plans are presented in this paper. (author)

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

Methodologies for hydrogen determination in metal oxides by prompt gamma activation analysis

International Nuclear Information System (INIS)

Alvarez, E.; Biegalski, S.R.; Landsberger, S.

2007-01-01

Prompt gamma activation analysis (PGAA), available at University of Texas at Austin (UT), has been employed for the direct determination of hydrogen content in a series of metal oxide materials typically used as cathodes in lithium ion battery systems. Special attention was given to the experimental setup including potential sources of error and system calibration for the detection of hydrogen. Spectral interference with hydrogen arising from cobalt was identified and corrected for. Limits of detection as a function of cobalt mass present in a given sample are also discussed. PGAA has proven to be a novel and precise technique for the determination of hydrogen in metal oxides. This type of investigation could provide valuable insight regarding the factors that limit the practical capacities of lithium ion oxide cathodes

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)

Effect of sample moisture and bulk density on performance of the 241Am-Be source based prompt gamma rays neutron activation analysis setup. A Monte Carlo study

International Nuclear Information System (INIS)

Almisned, Ghada

2010-01-01

Monte Carlo simulations were carried out using the dependence of gamma ray yield on the bulk density and moisture content for five different lengths of Portland cement samples in a thermal neutron capture based Prompt Gamma ray Neutron Activation Analysis (PGNAA) setup for source inside moderator geometry using an 241 Am-Be neutron source. In this study, yields of 1.94 and 6.42 MeV prompt gamma rays from calcium in the five Portland cement samples were calculated as a function of sample bulk density and moisture content. The study showed a strong dependence of the 1.94 and 6.42 MeV gamma ray yield upon the sample bulk density but a weaker dependence upon sample moisture content. For an order of magnitude increase in the sample bulk density, an order of magnitude increase in the gamma rays yield was observed, i.e., a one-to-one correspondence. In case of gamma ray yield dependence upon sample moisture content, an order of magnitude increase in the moisture content of the sample resulted in about 16-17% increase in the yield of 1.94 and 6.42 MeV gamma rays from calcium. (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

Direct determination of Cd, Hg in liver and kidney by prompt gamma activation analysis

International Nuclear Information System (INIS)

Vuong Huu tan; Tran Tuan Anh; Nguyen Canh Hai; Le Van Lieu

2000-01-01

The development of a method for in-vivo measurement of some elemental concentration in organs making use of prompt gamma activation analysis with the filtered neutron beam at the Dalat reactor is being carried out. In this paper we present primary results in research and development of an IVPGNAA facility at the Dalat reactor. Beside the description of experimental set-up, it consists of determination of thermal neutron flux distribution in phantom, and the evaluation of the detection limit and analytical sensitivity for Cd and Hg in the kidney and the liver. Discussions are given to improve the IVPGNAA facility in the future. (author)

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

Measurement of (n,xn) reaction cross-sections using prompt {gamma} spectroscopy at neutron beams with high instantaneous flux; Mesure de sections efficaces de reaction (n,xn) par spectroscopie {gamma} prompte aupres d'un faisceau a tres haut flux instantane

Energy Technology Data Exchange (ETDEWEB)

Lukic, S

2004-10-15

The work presented in this thesis is situated in the context of the GEDEON program of neutron cross-section measurements. This program is motivated by the perspectives recently opened by projects of nuclear waste treatment and energy production. There is an obvious lack of experimental data on (n,xn) reactions in the databases, especially in the case of very radioactive isotopes. An important technique to measure cross-sections of these reactions is the prompt {gamma}-ray spectroscopy at white pulsed neutron beams with very high instantaneous flux. In this work, inelastic scattering and (n,xn) reactions cross-section measurements were performed on a lead sample from threshold to 20 MeV by prompt {gamma}-ray spectroscopy at the white neutron beam generated by GELINA facility in Geel, Belgium. Digital methods were developed to treat HPGe CLOVER detector signals and separate {gamma}-rays induced by the fastest neutrons from those belonging to the flash. Partial cross-sections for the production of several transitions in natural lead were measured and analyzed using theoretical calculations in order to separate the contributions of different reactions leading to the same residual isotope. Total cross-sections of the reactions in question were estimated. The results were compared to the TALYSS code theoretical calculations, as well as to other experimental results. This experiment has served to validate the method and it opens the way to measure (n,xn) reactions cross-sections with high instantaneous neutron flux on actinides, particularly the U{sup 233}(n,2n) reaction which is important for the thorium cycle. (author)

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)

Prompt radiation activation analysis, (1) Theoretical study

International Nuclear Information System (INIS)

EL Barouni, A. M.; Araddad, S. Y.; Mosbah, D. S.; Elfakhri, S. M.; Rateb, J. M.; Benghzail, M. A.

2004-01-01

The measurement of the prompt γ following neutron capture in the reaction has been extensively developed. In this method the gamma-ray intensity is depended only upon the radiative capture cross-section and not upon the half-life of the product nucleus. The prompt gamma-ray activation analysis method stems from the radiative capture process which results in the decay of the compound nucleus by the emission of characteristic gamma radiation, either as a single photon with kinetic energy equal to the excitation energy less the recoil energy or, more likely, by a cascade of two or more photons with the same energy. The equations and the computer program required to calculate the yield, the intensity and the K χ emission probability per disintegration, are given in this study.(author)

Prompt gamma-ray spectroscopy and its use for the elemental chemical analysis

International Nuclear Information System (INIS)

Deconninck, G.; Demortier, G.; Bodart, F.

The elemental chemical analysis by nuclear techniques has been widely developed since a quarter of century. In this review the analysis by irradiation of the the sample (solid or liquid) of a majority of chemical elements by means of the charged particles and the detection during this irradiation of the gamma photons characteristic of the element are considered. After a brief account of the physical phenomena peculiar to the prompt detection of photons in comparison with the activation methods where a delayed activity is measured, a brief description of the experimental equipment for this kind of analysis is given. A comprehensive critical survey of the recent applications to the analysis of metals, semiconductors and electric insulating substances is presented. The necessary informations for the choice of the nuclear reaction to use for a specific analysis are contained in a set of tables. (AF)

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.

Measurement of prompt gamma profiles in inhomogeneous targets with a knife-edge slit camera during proton irradiation

International Nuclear Information System (INIS)

Priegnitz, M; Helmbrecht, S; Fiedler, F; Janssens, G; Smeets, J; Vander Stappen, F; Perali, I; Sterpin, E

2015-01-01

Proton and ion beam therapies become increasingly relevant in radiation therapy. To fully exploit the potential of this irradiation technique and to achieve maximum target volume conformality, the verification of particle ranges is highly desirable. Many research activities focus on the measurement of the spatial distributions of prompt gamma rays emitted during irradiation. A passively collimating knife-edge slit camera is a promising option to perform such measurements. In former publications, the feasibility of accurate detection of proton range shifts in homogeneous targets could be shown with such a camera. We present slit camera measurements of prompt gamma depth profiles in inhomogeneous targets. From real treatment plans and their underlying CTs, representative beam paths are selected and assembled as one-dimensional inhomogeneous targets built from tissue equivalent materials. These phantoms have been irradiated with monoenergetic proton pencil beams. The accuracy of range deviation estimation as well as the detectability of range shifts is investigated in different scenarios. In most cases, range deviations can be detected within less than 2 mm. In close vicinity to low-density regions, range detection is challenging. In particular, a minimum beam penetration depth of 7 mm beyond a cavity is required for reliable detection of a cavity filling with the present setup. Dedicated data post-processing methods may be capable of overcoming this limitation. (paper)

Determination of Cu-Zn Fraction of an Ancient Brass Pipe by Prompt Gamma-ray Activation Analysis

Energy Technology Data Exchange (ETDEWEB)

Sun, G. M.; Lee, Y. N.; Moon, J. H.; Lee, K. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2009-05-15

Prompt Gamma Activation Analysis (PGAA) has an advantage over most other methods in the investigation of archeological and cultural objects which must be dealt with a non-destructive method. In this study, we study about how to determine the copper-zinc fraction in archeological objects such as a smoking pipe made from brass, where the proportions of copper and zinc can be varied to create a range of brasses with varying properties. In this study, a Japanese smoking pipe was analyzed to determine the copper-zinc fraction at the KAERI-SNU PGAA facility.

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)

Prompt gamma neutron activation analysis of toxic elements in radioactive waste packages

Energy Technology Data Exchange (ETDEWEB)

Ma, J.-L. [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 St Paul-lez-Durance (France); Carasco, C., E-mail: cedric.carasco@cea.fr [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 St Paul-lez-Durance (France); Perot, B. [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 St Paul-lez-Durance (France); Mauerhofer, E.; Kettler, J.; Havenith, A. [Institute of Energy and Climate Research - Nuclear Waste Management and Reactor Safety, Forschungszentrum Juelich GmbH (Germany)

2012-07-15

The French Alternative Energies and Atomic Energy Commission (CEA) and National Radioactive Waste Management Agency (ANDRA) are conducting an R and D program to improve the characterization of long-lived and medium activity (LL-MA) radioactive waste packages. In particular, the amount of toxic elements present in radioactive waste packages must be assessed before they can be accepted in repository facilities in order to avoid pollution of underground water reserves. To this aim, the Nuclear Measurement Laboratory of CEA-Cadarache has started to study the performances of Prompt Gamma Neutron Activation Analysis (PGNAA) for elements showing large capture cross sections such as mercury, cadmium, boron, and chromium. This paper reports a comparison between Monte Carlo calculations performed with the MCNPX computer code using the ENDF/B-VII.0 library and experimental gamma rays measured in the REGAIN PGNAA cell with small samples of nickel, lead, cadmium, arsenic, antimony, chromium, magnesium, zinc, boron, and lithium to verify the validity of a numerical model and gamma-ray production data. The measurement of a {approx}20 kg test sample of concrete containing toxic elements has also been performed, in collaboration with Forschungszentrum Juelich, to validate the model in view of future performance studies for dense and large LL-MA waste packages. - Highlights: Black-Right-Pointing-Pointer Comparison between measurements and MCNP calculation has been performed for a PGNAA system. Black-Right-Pointing-Pointer The system aims at controlling the amount of toxic elements in nuclear waste. Black-Right-Pointing-Pointer Simple samples and a concrete cylinder in which impurities have been added are used. Black-Right-Pointing-Pointer Calculations agree within a factor 2 with measurements. Black-Right-Pointing-Pointer The system can be improved with a better neutron flux monitoring and the use of boron-free graphite.

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)

Measurement of total body chlorine by prompt gamma in vivo neutron activation analysis

International Nuclear Information System (INIS)

Beddoe, A.H.; Streat, S.J.; Hill, G.L.

1987-01-01

A method of measuring total body chlorine (TBCl) by prompt gamma in vivo neutron activation analysis is described depending on the same NaI(Tl) spectra used for determinations of total body nitrogen. Ratios of chlorine to hydrogen are derived and TBCl determined using a model of body composition depending on measured body weight, total body water (by tritium dilution) and protein (6.25 x nitrogen) as well as estimated body minerals and glycogen. The precision of the method based on scanning an anthropomorphic phantom is approximately 9% (SD), for a patient dose equivalent of less than 0.30 mSv. Spectra collected from 67 normal volunteers (32 male, 35 female) yielded mean values of TBCl of 72 +- 19 (SD) g in males and 53.6 +- 15 g in females, in broad agreement with values reported by workers using delayed gamma methods. Results are presented for two human cadavers analysed by neutron activation and conventional chemical analysis; the ratios of TBCl (neutron activation) to TBCl (chemical) were 0.980 +- 0.028 (SEM) and 0.91 +- 0.09. It is suggested that an improvement in precision will be achieved by increasing the scanning time (thereby increasing the radiation dose equivalent) and by adding two more detectors. (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)

Design of a Compton camera for 3D prompt-{gamma} imaging during ion beam therapy

Energy Technology Data Exchange (ETDEWEB)

Roellinghoff, F., E-mail: roelling@ipnl.in2p3.fr [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); INSA-Lyon Laboratory of Nondestructive Testing using Ionizing Radiation (CNDRI), F-69621 Villeurbanne Cedex (France); Richard, M.-H., E-mail: mrichard@ipnl.in2p3.fr [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); INSA-Lyon Laboratory of Nondestructive Testing using Ionizing Radiation (CNDRI), F-69621 Villeurbanne Cedex (France); Chevallier, M.; Constanzo, J.; Dauvergne, D. [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); Freud, N. [INSA-Lyon Laboratory of Nondestructive Testing using Ionizing Radiation (CNDRI), F-69621 Villeurbanne Cedex (France); Henriquet, P.; Le Foulher, F. [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); Letang, J.M. [INSA-Lyon Laboratory of Nondestructive Testing using Ionizing Radiation (CNDRI), F-69621 Villeurbanne Cedex (France); Montarou, G. [LPC, CNRS/IN2P3, Clermont-F. University (France); Ray, C.; Testa, E.; Testa, M. [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); Walenta, A.H. [Uni-Siegen, FB Physik, Emmy-Noether Campus, D-57068 Siegen (Germany)

2011-08-21

We investigate, by means of Geant4 simulations, a real-time method to control the position of the Bragg peak during ion therapy, based on a Compton camera in combination with a beam tagging device (hodoscope) in order to detect the prompt gamma emitted during nuclear fragmentation. The proposed set-up consists of a stack of 2 mm thick silicon strip detectors and a LYSO absorber detector. The {gamma} emission points are reconstructed analytically by intersecting the ion trajectories given by the beam hodoscope and the Compton cones given by the camera. The camera response to a polychromatic point source in air is analyzed with regard to both spatial resolution and detection efficiency. Various geometrical configurations of the camera have been tested. In the proposed configuration, for a typical polychromatic photon point source, the spatial resolution of the camera is about 8.3 mm FWHM and the detection efficiency 2.5x10{sup -4} (reconstructable photons/emitted photons in 4{pi}). Finally, the clinical applicability of our system is considered and possible starting points for further developments of a prototype are discussed.

Performance test results of noninvasive characterization of RCRA surrogate waste by prompt gamma neutron activation analysis

International Nuclear Information System (INIS)

Gehrke, R.J.; Propp, W.A.

1997-11-01

A performance evaluation to determine the feasibility of using prompt gamma neutron activation analysis (PGNAA) for noninvasive, quantitative assay of mixed waste containers was sponsored by DOE's Office of Technology Development (OTD), the Mixed Waste Focus Area (MWFA), and the Idaho National Engineering and Environmental Laboratory (INEEL). The evaluation was conducted using a surrogate waste, based on Portland cement, that was spiked with three RCRA metals, mercury, cadmium, and lead. The results indicate that PGNAA has potential as a process monitor. However, further development is required to improve its sensitivity to meet regulatory requirements for determination of these RCRA metals

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.

Study of the prompt gamma ray signal from fissions in special nuclear materials induced using an associated particle neutron generator

International Nuclear Information System (INIS)

Koltick, D. S.; Kane, S. Z.

2009-01-01

More than 42 million cargo containers entered the United States in 2005. To search for a few kilograms of special nuclear material (SNM) within this vast stream of cargo, an inspection system based on neutron-induced fission followed by the coincident detection of multiple prompt fission gamma rays is investigated using MCNP-Polimi code. The system utilizes two deuterium-tritium (DT) associated particle neutron generators, each capable of 10 9 neutrons/s at 14.1 MeV, with sub-nanosecond timing resolution ZnO:Ga alpha detectors internal to the generator. Because prompt fission signals are approximately 100 times stronger than the delayed signals, the neutron flux is greatly reduced compared to 10 11-12 neutrons/s required for systems based on delayed signals such as the 'nuclear car wash' [4]. In addition the system utilizes 30 cm deep liquid krypton (LKr) noble gas detectors having 94% detection efficiency for 1 MeV gamma rays, high solid angle coverage (∼ 50% of the total solid angle), and sub-nanosecond timing resolution (∼ 600 ps). An algorithm for distinguishing U-235 from U-238 is presented. (authors)

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.

Prompt γ energy spectrum by associated particle technique

International Nuclear Information System (INIS)

An Li; He Tie; Guo Haiping; Yang Jian; Zheng Pu; Wang Xinhua; Chen Yuan; Mou Yunfeng; Zhu Chuanxin; Yang Xiaofei

2010-01-01

The basic principle of associated alpha particle technique and the measurement system were introduced. The characteristic prompt gamma-rays coming from water, graphite, liquid nitrogen, ammonium nitrate, melamine and simulated samples induced by D-T neutron from generator were gained by single alpha particle detector and gamma-ray detector. The complex gamma-ray spectra were deconvolved. The element ratio between the experiment and chemic molecular formula is agreement in 10%. (authors)

Status of prompt gamma neutron activation analysis (PGAA) at TRR-1/M1 (Thai Research Reactor-1/Modified 1)

Energy Technology Data Exchange (ETDEWEB)

Asvavijnijkulchai, Chanchai; Dharmavanij, Wanchai; Siangsanan, Pariwat; Ratanathongchai, Wichian; Chongkum, Somporn [Physics Division, Office of Atomic Energy for Peace, Vibhavadi Rangsit Road, Chatuchak, Bangkok (Thailand)

1999-08-01

The first prompt gamma activation analysis (PGAA) was designed, constructed and installed at a 6 inch diameter neutron beam port of the Thai Research Reactor-1/Modified 1 (TRR-1/M1) since 1989. Beam characteristic were made by Gd foil irradiation, X-ray film exposing and densitometry scanning consequently. The thermal neutron flux at sample position was measured by Au foil activation, and was about 1 x 10{sup 7} n.cm{sup 2}.sec{sup -1} at 700 kW operating power. The experiments have been conducted successfully. In 1998, the PGAA facility has been developed for the reactor operating power at 1.2 MW. The new PGAA system, e.g., beam shutter, gamma collimator and biological shields have been designed to reduce the leakage of neutrons and gamma radiation to the acceptance levels in accordance with the International Commission on Radiation Protection Publication 60 (ICRP 60). The construction and installation will be completed in April 1999. (author)

Status of prompt gamma neutron activation analysis (PGAA) at TRR-1/M1 (Thai Research Reactor-1/Modified 1)

International Nuclear Information System (INIS)

Asvavijnijkulchai, Chanchai; Dharmavanij, Wanchai; Siangsanan, Pariwat; Ratanathongchai, Wichian; Chongkum, Somporn

1999-01-01

The first prompt gamma activation analysis (PGAA) was designed, constructed and installed at a 6 inch diameter neutron beam port of the Thai Research Reactor-1/Modified 1 (TRR-1/M1) since 1989. Beam characteristic were made by Gd foil irradiation, X-ray film exposing and densitometry scanning consequently. The thermal neutron flux at sample position was measured by Au foil activation, and was about 1 x 10 7 n.cm 2 .sec -1 at 700 kW operating power. The experiments have been conducted successfully. In 1998, the PGAA facility has been developed for the reactor operating power at 1.2 MW. The new PGAA system, e.g., beam shutter, gamma collimator and biological shields have been designed to reduce the leakage of neutrons and gamma radiation to the acceptance levels in accordance with the International Commission on Radiation Protection Publication 60 (ICRP 60). The construction and installation will be completed in April 1999. (author)

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)

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Feynman-α correlation analysis by prompt-photon detection

International Nuclear Information System (INIS)

Hashimoto, Kengo; Yamada, Sumasu; Hasegawa, Yasuhiro; Horiguchi, Tetsuo

1998-01-01

Two-detector Feynman-α measurements were carried out using the UTR-KINKI reactor, a light-water-moderated and graphite-reflected reactor, by detecting high-energy, prompt gamma rays. For comparison, the conventional measurements by detecting neutrons were also performed. These measurements were carried out in the subcriticality range from 0 to $1.8. The gate-time dependence of the variance-and covariance-to-mean ratios measured by gamma-ray detection were nearly identical with those obtained using standard neutron-detection techniques. Consequently, the prompt-neutron decay constants inferred from the gamma-ray correlation data agreed with those from the neutron data. Furthermore, the correlated-to-uncorrelated amplitude ratios obtained by gamma-ray detection significantly depended on the low-energy discriminator level of the single-channel analyzer. The discriminator level was determined as optimum for obtaining a maximum value of the amplitude ratio. The maximum amplitude ratio was much larger than that obtained by neutron detection. The subcriticality dependence of the decay constant obtained by gamma-ray detection was consistent with that obtained by neutron detection and followed the linear relation based on the one-point kinetic model in the vicinity of delayed critical. These experimental results suggest that the gamma-ray correlation technique can be applied to measure reactor kinetic parameters more efficiently

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).

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

International Nuclear Information System (INIS)

Genreith, Christoph

2015-01-01

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

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.

Sample dependent response of a LaCl{sub 3}:Ce detector in prompt gamma neutron activation analysis of bulk hydrocarbon samples

Energy Technology Data Exchange (ETDEWEB)

Naqvi, A.A., E-mail: aanaqvi@kfupm.edu.sa [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Al-Matouq, Faris A.; Khiari, F.Z. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Isab, A.A. [Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Khateeb-ur-Rehman,; Raashid, M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

2013-08-11

The response of a LaCl{sub 3}:Ce detector has been found to depend upon the hydrogen content of bulk samples in prompt gamma analysis using 14 MeV neutron inelastic scattering. The moderation of 14 MeV neutrons from hydrogen in the bulk sample produces thermal neutrons around the sample which ultimately excite chlorine capture gamma rays in the LaCl{sub 3}:Ce detector material. Interference of 6.11 MeV chlorine gamma rays from the detector itself with 6.13 MeV oxygen gamma rays from the bulk samples makes the intensity of the 6.13 MeV oxygen gamma ray peak relatively insensitive to variations in oxygen concentration. The strong dependence of the 1.95 MeV doublet chlorine gamma ray yield on hydrogen content of the bulk samples confirms fast neutron moderation from hydrogen in the bulk samples as a major source of production of thermal neutrons and chlorine gamma rays in the LaCl{sub 3}:Ce detector material. Despite their poor oxygen detection capabilities, these detectors have nonetheless excellent detection capabilities for hydrogen and carbon in benzene, butyl alcohol, propanol, propanic acid, and formic acid bulk samples using 14 MeV neutron inelastic scattering.

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

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)

First test of the prompt gamma ray timing method with heterogeneous targets at a clinical proton therapy facility

International Nuclear Information System (INIS)

Hueso-González, Fernando; Enghardt, Wolfgang; Golnik, Christian; Petzoldt, Johannes; Pausch, Guntram; Fiedler, Fine; Priegnitz, Marlen; Römer, Katja E; Wagner, Andreas; Janssens, Guillaume; Prieels, Damien; Smeets, Julien; Vander Stappen, François

2015-01-01

Ion beam therapy promises enhanced tumour coverage compared to conventional radiotherapy, but particle range uncertainties significantly blunt the achievable precision. Experimental tools for range verification in real-time are not yet available in clinical routine. The prompt gamma ray timing method has been recently proposed as an alternative to collimated imaging systems. The detection times of prompt gamma rays encode essential information about the depth-dose profile thanks to the measurable transit time of ions through matter. In a collaboration between OncoRay, Helmholtz-Zentrum Dresden-Rossendorf and IBA, the first test at a clinical proton accelerator (Westdeutsches Protonentherapiezentrum Essen, Germany) with several detectors and phantoms is performed. The robustness of the method against background and stability of the beam bunch time profile is explored, and the bunch time spread is characterized for different proton energies. For a beam spot with a hundred million protons and a single detector, range differences of 5 mm in defined heterogeneous targets are identified by numerical comparison of the spectrum shape. For higher statistics, range shifts down to 2 mm are detectable. A proton bunch monitor, higher detector throughput and quantitative range retrieval are the upcoming steps towards a clinically applicable prototype. In conclusion, the experimental results highlight the prospects of this straightforward verification method at a clinical pencil beam and settle this novel approach as a promising alternative in the field of in vivo dosimetry. (paper)

Effects of sample and spectrum characteristics on cold and thermal neutron prompt gamma activation analysis in environmental studies of plants

International Nuclear Information System (INIS)

Robinson, L.; Zhao, L.

2009-01-01

Previous studies including the development of methods for the determination of carbon, nitrogen, and phosphorus in cattail using cold neutron prompt gamma activation (CNPGAA) and thermal neutron prompt gamma activation analysis (TNPGAA); evaluation of the precision and accuracy of these methods through the analysis of Standard Reference Materials (SRMs); and comparison of the sensitivity of CNPGAA to TNPGAA have been done in the CNPGAA and TNPGAA facilities at the National Institute of Standards and Technology (NIST). This paper integrates the findings from all of these prior studies and presents recommendations for the application of CNPGAA and TNPGAA in environmental studies of plants based on synergistic considerations of the effects of neutron energy, matrix factors such as chlorine content, Compton scattering, hydrogen content, sample thickness, and spectral interferences from Cl on the determination of C, N, and P. This paper also provides a new approach that simulates a sensitivity curve for an element of interest (S), which is a function of hydrogen content (X) and sample thickness (Y) as follows: S = aX + bY + c (where a, b, and c are constants). This approach has provided more accurate results from the analysis of SRMs than traditional methods and an opportunity to use models to optimize experimental conditions. (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)

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

Prompt Neutrino Emission of Gamma-ray Bursts in the Dissipative Photospheric Scenario Revisited: Possible Contributions from Cocoons

Energy Technology Data Exchange (ETDEWEB)

Xiao, Di; Dai, Zi-Gao [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Mészáros, Peter, E-mail: dzg@nju.edu.cn [Center for Particle and Gravitational Astrophysics, Department of Physics, Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States)

2017-07-01

High-energy neutrinos are expected to originate from different stages in a gamma-ray burst (GRB) event. In this work, we revisit the dissipative photospheric scenario, in which the GRB prompt emission is produced around the photospheric radius. Meanwhile, possible dissipation mechanisms (e.g., internal shocks or magnetic reconnection) could accelerate cosmic-rays (CRs) to ultra-high energies and then produce neutrinos via hadronuclear and photohadronic processes, which are referred to as prompt neutrinos . In this paper, we obtain the prompt neutrino spectrum of a single GRB within a self-consistent analytical framework, in which the jet-cocoon structure and possible collimation effects are included. We investigate a possible neutrino signal from the cocoon, which has been ignored in the previous studies. We show that if a GRB event happens at a distance of the order of Mpc, there is a great chance to observe the neutrino emission from the cocoon by IceCube, which is even more promising than jet neutrinos, as the opening angle of the cocoon is much larger. We also determine the diffuse neutrino flux of GRB cocoons and find that it could be comparable with that of the jets. Our results are consistent with the latest result reported by the IceCube collaboration that no significant correlation between neutrino events and observed GRBs is seen in the new data.

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.

Prompt and delay gamma ray measurements for 'in vivo' neutron activation analysis using a cyclic system

International Nuclear Information System (INIS)

Matthews, I.P.

1979-09-01

Early attempts at determining the elemental composition of the body by radioactive isotope dilution techniques are reviewed. The development and current status of in-vivo neutron activation analysis and the ways in which it supersedes or supplements certain of the former techniques are outlined. An irradiation facility is described which employs a 5 Ci neutron source and is capable of performing prompt and delay γ-ray measurements as well as cyclic activation. The uniformity of thermal neutron flux in a phantom is demonstrated and the neutron spectrum at a depth in the phantom has been obtained by means of threshold detectors. An examination is made of the possible applications of the Monte Carlo method to the design of irradiation and detection facilities and in yielding information about inaccessible areas. Detection limits for the bulk body elements and trace elements are presented. It is shown that the depth of a region of the body can be determined from a prompt gamma ray spectrum. This technique can be used to correct measurements when it is known that activation and detection is non-uniform. The feasibility of using a C.T. whole body scanner to measure bone demineralisation is explored. (author)

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

Analysis of marine samples by neutron-induced prompt gamma-ray technique and ICP-MS

International Nuclear Information System (INIS)

Yonezawa, C.; Matsue, H.; McKay, K.; Povinec, P.

2001-01-01

Multi-element and isotopic analyses of oils and marine environmental samples were carried out to estimate a contamination source using a 'finger printing' method. Elemental analyses were carried out using neutron-induced prompt gamma-ray analysis (PGA), instrumental neutron activation analysis (INAA) at the Japan Atomic Institute, Tokai-mura, Japan (JAERI) and ICP-MS in the IAEA Marine Environment Laboratory, Monaco (MEL). Fifteen elements including light elements, H, B, N, Si and Ca, which cannot be determined by INAA and ICP-MS, were determined by PGA. A total of 47 elements were determined in the present study. The potential of PGA for the determination of isotopic ratios was tested by measuring 34 S/ 32 S ratios in oils. The evaluation of historical records of marine environmental conditions using annual bands in coral samples was also investigated. (author)

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

Clustering of gamma-ray burst types in the Fermi GBM catalogue: indications of photosphere and synchrotron emissions during the prompt phase

Science.gov (United States)

Acuner, Zeynep; Ryde, Felix

2018-04-01

Many different physical processes have been suggested to explain the prompt gamma-ray emission in gamma-ray bursts (GRBs). Although there are examples of both bursts with photospheric and synchrotron emission origins, these distinct spectral appearances have not been generalized to large samples of GRBs. Here, we search for signatures of the different emission mechanisms in the full Fermi Gamma-ray Space Telescope/GBM (Gamma-ray Burst Monitor) catalogue. We use Gaussian Mixture Models to cluster bursts according to their parameters from the Band function (α, β, and Epk) as well as their fluence and T90. We find five distinct clusters. We further argue that these clusters can be divided into bursts of photospheric origin (2/3 of all bursts, divided into three clusters) and bursts of synchrotron origin (1/3 of all bursts, divided into two clusters). For instance, the cluster that contains predominantly short bursts is consistent of photospheric emission origin. We discuss several reasons that can determine which cluster a burst belongs to: jet dissipation pattern and/or the jet content, or viewing angle.

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

Prompt photon production in photoproduction at HERA

Energy Technology Data Exchange (ETDEWEB)

Nowak, Krzysztof

2010-03-15

This thesis presents measurement of the production of prompt photons in photoproduction with the H1 experiment at HERA. The analysis is based on the data taken in the years 2004-2007, with a total integrated luminosity of 340 pb{sup -1}. The main difficulty of the measurement comes from the high background of neutral mesons decaying into photons. It is accounted for with the help of multivariate analysis. Prompt photon cross sections are measured with the low negative four-momentum transfer squared Q{sup 2} < 1GeV{sup 2} and in the inelasticity range 0.1 < y < 0.7 for photons with a transverse energy 6 < E{sub T}{sup {gamma}} < 15GeV and in the pseudorapidity range.1.0 < {eta}{sup {gamma}} < 2.4 as a function of photons transverse energy and its pseudorapidity. Cross sections for prompt photon events with an additional hadronic jet are measured as a function of the transverse energy and pseudorapidity of the jet and of the momentum fractions x{sub {gamma}} and x{sub p} of the incident photon and proton carried by the constituents participating in the hard scattering process. Additionally, the transverse correlation between the photon and the jet is studied. The results are compared with predictions of a next-to-leading order calculation and a calculation based on the k{sub T} factorisation approach. Neither of calculations is able to describe all the aspects of the measurement. (orig.)

Prompt gamma activation analysis (PGAA) and short-lived neutron activation analysis (NAA) applied to the characterization of legacy materials

International Nuclear Information System (INIS)

English, G.A.; Firestone, R.B.; Perry, D.L.; Reijonen, J.P.; Ka-Ngo Leung; Garabedian, G.F.; Molnar, G.L.; Revay, Zs.

2008-01-01

Without quality historical records that provide the composition of legacy materials, the elemental and/or chemical characterization of such materials requires a manual analytical strategy that may expose the analyst to unknown toxicological hazards. In addition, much of the existing legacy inventory also incorporates radioactivity, and, although radiological composition may be determined by various nuclear-analytical methods, most importantly, gamma-spectroscopy, current methods of chemical characterization still require direct sample manipulation, thereby presenting special problems with broad implications for both the analyst and the environment. Alternately, prompt gamma activation analysis (PGAA) provides a 'single-shot' in-situ, non-destructive method that provides a complete assay of all major entrained elemental constituents. Additionally, neutron activation analysis (NAA) using short-lived activation products complements PGAA and is especially useful when NAA activation surpasses the PGAA in elemental sensitivity. (author)

Prompt gamma activation analysis (PGAA) and short-lived neutron activation analysis (NAA) applied to the characterization of legacy materials

International Nuclear Information System (INIS)

Firestone, Richard B; English, G.A.; Firestone, R.B.; Perry, D.L.; Reijonen, J.P.; Leung, Ka-Ngo; Garabedian, G.F.; Molnar, G.L.; Revay, Zs.

2008-01-01

Without quality historical records that provide the composition of legacy materials, the elemental and/or chemical characterization of such materials requires a manual analytical strategy that may expose the analyst to unknown toxicological hazards. In addition, much of the existing legacy inventory also incorporates radioactivity, and, although radiological composition may be determined by various nuclear-analytical methods, most importantly, gamma-spectroscopy, current methods of chemical characterization still require direct sample manipulation, thereby presenting special problems with broad implications for both the analyst and the environment. Alternately, prompt gamma activation analysis (PGAA) provides a 'single-shot' in-situ, non-destructive method that provides a complete assay of all major entrained elemental constituents.1-3. Additionally, neutron activation analysis (NAA) using short-lived activation products complements PGAA and is especially useful when NAA activation surpasses the PGAA in elemental sensitivity

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.

Technical Note: Experimental carbon ion range verification in inhomogeneous phantoms using prompt gammas

Energy Technology Data Exchange (ETDEWEB)

Pinto, M.; Dauvergne, D.; Dedes, G.; Krimmer, J.; Ray, C.; Testa, E., E-mail: e.testa@ipnl.in2p3.fr; Testa, M. [IPNL, Université de Lyon, Lyon F-69003 |(France); Université Lyon 1, Villeurbanne F-69622 (France); CNRS/IN2P3, UMR 5822, Villeurbanne F-69622 (France); De Rydt, M. [IPNL, Université de Lyon, Lyon F-69003 (France); Université Lyon 1, Villeurbanne F-69622 (France); CNRS/IN2P3, UMR 5822, Villeurbanne F-69622 (France); Instituut voor Kern- en Stralingsfysica, KU Leuven, Celestijnenlaan 200D, Leuven B-3001 (Belgium); Freud, N.; Létang, J. M. [CREATIS, Université de Lyon, Lyon F-69003 (France); Université Lyon 1, Villeurbanne F-69622 (France); CNRS UMR 5220, INSERM U1044, INSA-Lyon, Centre Léon Bérard, 69008 Lyon (France)

2015-05-15

Purpose: The purpose of this study was to experimentally assess the possibility to monitor carbon ion range variations—due to tumor shift and/or elongation or shrinking—using prompt-gamma (PG) emission with inhomogeneous phantoms. Such a study is related to the development of PG monitoring techniques to be used in a carbon ion therapy context. Methods: A 95 MeV/u carbon ion beam was used to irradiate phantoms with a variable density along the ion path to mimic the presence of bone and lung in homogeneous humanlike tissue. PG profiles were obtained after a longitudinal scan of the phantoms. A setup comprising a narrow single-slit collimator and two detectors placed at 90° with respect to the beam axis was used. The time of flight technique was applied to allow the selection between PG and background events. Results: Using the positions at 50% entrance and 50% falloff of the PG profiles, a quantity called prompt-gamma profile length (PGPL) is defined. It is possible to observe shifts in the PGPL when there are absolute ion range shifts as small as 1–2 mm. Quantitatively, for an ion range shift of −1.33 ± 0.46 mm (insertion of a Teflon slab), a PGPL difference of −1.93 ± 0.58 mm and −1.84 ± 1.27 mm is obtained using a BaF{sub 2} and a NaI(Tl) detector, respectively. In turn, when an ion range shift of 4.59 ± 0.42 mm (insertion of a lung-equivalent material slab) is considered, the difference is of 4.10 ± 0.54 and 4.39 ± 0.80 mm for the same detectors. Conclusions: Herein, experimental evidence of the usefulness of employing PG to monitor carbon ion range using inhomogeneous phantoms is presented. Considering the homogeneous phantom as reference, the results show that the information provided by the PG emission allows for detecting ion range shifts as small as 1–2 mm. When considering the expected PG emission from an energy slice in a carbon ion therapy scenario, the experimental setup would allow to retrieve the same PGPL as the high statistics of

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)

Prompt gamma-ray emission of GRB 170817A associated to GW 170817: A consistent picture

Science.gov (United States)

Ziaeepour, Houri

2018-05-01

The short GRB 170817A associated to the first detection of gravitation waves from a Binary Neutron Star (BNS) merger was in many ways unusual. Possible explanations are emission from a cocoon or cocoon break out, off-axis view of a structured or uniform jet, and on-axis ultra-relativistic jet with reduced density and Lorentz factor. Here we use a phenomenological model of shock evolution and synchrotron/self-Compton emission to simulate the prompt emission of GRB 170817A and to test above proposals. We find that synchrotron emission from a mildly relativistic cocoon with a Lorentz factor of 2-3, as considered in the literature, generates a too soft, too long, and too bright prompt emission. Off-axis view of an structured jet with a Lorentz factor of about 10 can reproduce observations, but needs a very efficient transfer of kinetic energy to electrons in internal shocks, which is disfavored by particle in cell simulations. We also comment on cocoon breakout as a mechanism for generation of the prompt gamma-ray. A relativistic jet with a Lorentz factor of about 100 and a density lower than typical short GRBs seems to be the most plausible model and we conclude that GRB 170817A was intrinsically faint. Based on this result and findings of relativistic magnetohydrodynamics simulations of BNS merger in the literature we discuss physical and astronomical conditions, which may lead to such faint short GRBs. We identify small mass difference of progenitor neutron stars, their old age and reduced magnetic field, and anti-alignment of spin-orbit angular momentum induced by environmental gravitational disturbances during the lifetime of the BNS as causes for the faintness of GRB 170817A. We predict that BNS mergers at lower redshifts generate on average fainter GRBs.

Measuring the energies and multiplicities of prompt gamma-ray emissions from neutron-induced fission of $^{235}$U using the STEFF spectrometer

CERN Document Server

AUTHOR|(CDS)2093036; Smith, Alastair Gavin; Wright, Tobias James

Following a NEA high priority nuclear data request, an experimental campaign to measure the prompt $\\gamma$-ray emissions from $^{235}$U has been performed. This has used the STEFF spectrometer at the new Experimental Area 2 (EAR2) within the neutron timeof-flight facility (n_TOF), a white neutron source facility at CERN with energies from thermal to approximately 1 GeV. Prior to the experimental campaign, STEFF has been optimised for the environment of EAR2. The experimental hall features a high background $\\gamma$-ray rate, due to the nature of the spallation neutron source. Thus an investigation into reduction of the background $\\gamma$-ray rate, encountered by the NaI(Tl) detector array of STEFF, has been carried out. This has been via simulations using the simulation package FLUKA. Various materials and shielding geometries have been investigated but the effects determined to be insufficient in reducing the background rate by a meaningful amount. The NaI(Tl) detectors have been modified to improve their ...

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.

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)

Development of a Compton camera for prompt-gamma medical imaging

Science.gov (United States)

Aldawood, S.; Thirolf, P. G.; Miani, A.; Böhmer, M.; Dedes, G.; Gernhäuser, R.; Lang, C.; Liprandi, S.; Maier, L.; Marinšek, T.; Mayerhofer, M.; Schaart, D. R.; Lozano, I. Valencia; Parodi, K.

2017-11-01

A Compton camera-based detector system for photon detection from nuclear reactions induced by proton (or heavier ion) beams is under development at LMU Munich, targeting the online range verification of the particle beam in hadron therapy via prompt-gamma imaging. The detector is designed to be capable to reconstruct the photon source origin not only from the Compton scattering kinematics of the primary photon, but also to allow for tracking of the secondary Compton-scattered electrons, thus enabling a γ-source reconstruction also from incompletely absorbed photon events. The Compton camera consists of a monolithic LaBr3:Ce scintillation crystal, read out by a multi-anode PMT acting as absorber, preceded by a stacked array of 6 double-sided silicon strip detectors as scatterers. The detector components have been characterized both under offline and online conditions. The LaBr3:Ce crystal exhibits an excellent time and energy resolution. Using intense collimated 137Cs and 60Co sources, the monolithic scintillator was scanned on a fine 2D grid to generate a reference library of light amplitude distributions that allows for reconstructing the photon interaction position using a k-Nearest Neighbour (k-NN) algorithm. Systematic studies were performed to investigate the performance of the reconstruction algorithm, revealing an improvement of the spatial resolution with increasing photon energy to an optimum value of 3.7(1)mm at 1.33 MeV, achieved with the Categorical Average Pattern (CAP) modification of the k-NN algorithm.

LIMITS ON PROMPT, DISPERSED RADIO PULSES FROM GAMMA-RAY BURSTS

International Nuclear Information System (INIS)

Bannister, K. W.; Murphy, T.; Gaensler, B. M.; Reynolds, J. E.

2012-01-01

We have searched for prompt radio emission from nine gamma-ray bursts (GRBs) with a 12 m telescope at 1.4 GHz, with a time resolution of 64 μs to 1 s. We detected single dispersed radio pulses with significances >6σ in the few minutes following two GRBs. The dispersion measures of both pulses are well in excess of the expected Galactic values, and the implied rate is incompatible with known sources of single dispersed pulses. The arrival times of both pulses also coincide with breaks in the GRB X-ray light curves. A null trial and statistical arguments rule out random fluctuations as the origin of these pulses with >95% and ∼97% confidence, respectively, although a simple population argument supports a GRB origin with confidence of only 2%. We caution that we cannot rule out radio frequency interference (RFI) as the origin of these pulses. If the single pulses are not related to the GRBs, we set an upper limit on the flux density of radio pulses emitted between 200 and 1800 s after a GRB of 1.27w –1/2 Jy, where 6.4 × 10 –5 s –3 s is the pulse width. We set a limit of less than 760 Jy for long timescale (>1 s) variations. These limits are some of the most constraining at high time resolution and GHz frequencies in the early stages of the GRB phenomenon.

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.

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

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)

Prompt and Afterglow Emission Properties of Gamma-Ray Bursts with Spectroscopically Identified Supernovae

Energy Technology Data Exchange (ETDEWEB)

Kaneko, Yuki; Ramirez-Ruiz, E.; Granot, J.; Kouveliotou, C.; Woosley, S.E.; Patel, S.K.; Rol, E.; Zand, J.J.M.in' t; a; Wijers, R.A.M.J.; Strom, R.; /USRA, Huntsville

2006-07-12

We present a detailed spectral analysis of the prompt and afterglow emission of four nearby long-soft gamma-ray bursts (GRBs 980425, 030329, 031203, and 060218) that were spectroscopically found to be associated with type Ic supernovae, and compare them to the general GRB population. For each event, we investigate the spectral and luminosity evolution, and estimate the total energy budget based upon broadband observations. The observational inventory for these events has become rich enough to allow estimates of their energy content in relativistic and sub-relativistic form. The result is a global portrait of the effects of the physical processes responsible for producing long-soft GRBs. In particular, we find that the values of the energy released in mildly relativistic outflows appears to have a significantly smaller scatter than those found in highly relativistic ejecta. This is consistent with a picture in which the energy released inside the progenitor star is roughly standard, while the fraction of that energy that ends up in highly relativistic ejecta outside the star can vary dramatically between different events.

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)

An extended study of prompt photon photoproduction at HERA with k{sub T}-factorization

Energy Technology Data Exchange (ETDEWEB)

Lipatov, A.V.; Malyshev, M.A.; Zotov, N.P. [Moskovskij Gosudarstvennyj Univ., Moscow (Russian Federation). Nauchno-Issledovatel' skij Inst. Yadernoj Fiziki

2013-08-15

We reconsider the prompt photon photoproduction at HERA in the framework of the k{sub T}-factorization QCD approach. The proposed method is based on the O({alpha}{sup 2}{alpha}{sub s}) amplitudes for {gamma}q{yields}{gamma}gq and {gamma}g{sup *}{yields}{gamma}q anti q partonic subprocesses. Additionally, we take into account the O({alpha}{sup 2}{alpha}{sub s}{sup 2}) box contributions {gamma}g{yields}{gamma}g to the production cross sections. The unintegrated (or transverse momentum dependent) parton densities in the proton are determined using Kimber-Martin-Ryskin (KMR) prescription. Our consideration covers both inclusive and jet associated prompt photon photoproduction rates. We find that our numerical predictions agree well with the recent data taken by H1 and ZEUS collaborations at HERA. We demonstrate that the box contributions are sizeable and amount up to {proportional_to}15% of the calculated total cross section.

The boron concentration measurement by the prompt gamma-ray analysis device at JRR-4

International Nuclear Information System (INIS)

Hori, N.; Torii, Y.; Yamamoto, K.; Kishi, T.; Takada, J.

2000-01-01

In determining the dose for BNCT, it is important to measure the boron concentration in blood as well as the thermal neutron fluence. To attain an accurate measurement of the boron concentration in the whole blood at about 30 ppm, the Prompt Gamma-ray Analysis (PGA) is adopted to enable the measurement with a high degree of accuracy in short time, since the chemical analysis technique has some difficulties on it. In order to install the PGA device in a swimming pool type research reactor JRR-4, the super-mirror for obtaining the necessary neutron flux in the space over the pool surface was perpendicularly placed, because the reactor had no horizontal experiment tube for this kind of use. As the accurate measurement of the boron concentration in whole blood using PGA is enabled herewith, the first medical irradiation for BNCT at JRR-4 was carried out on October 25, 1999. (author)

A LINGERING NON-THERMAL COMPONENT IN THE GAMMA-RAY BURST PROMPT EMISSION: PREDICTING GeV EMISSION FROM THE MeV SPECTRUM

International Nuclear Information System (INIS)

Basak, Rupal; Rao, A. R.

2013-01-01

The high-energy GeV emission of gamma-ray bursts (GRBs) detected by Fermi/LAT has a significantly different morphology compared to the lower energy MeV emission detected by Fermi/GBM. Though the late-time GeV emission is believed to be synchrotron radiation produced via an external shock, this emission as early as the prompt phase is puzzling. A meaningful connection between these two emissions can be drawn only by an accurate description of the prompt MeV spectrum. We perform a time-resolved spectroscopy of the Gamma-ray Burst Monitor (GBM) data of long GRBs with significant GeV emission, using a model consisting of two blackbodies and a power law. We examine in detail the evolution of the spectral components and find that GRBs with high GeV emission (GRB 090902B and GRB 090926A) have a delayed onset of the power-law component in the GBM spectrum, which lingers at the later part of the prompt emission. This behavior mimics the flux evolution in the Large Area Telescope (LAT). In contrast, bright GBM GRBs with an order of magnitude lower GeV emission (GRB 100724B and GRB 091003) show a coupled variability of the total and the power-law flux. Further, by analyzing the data for a set of 17 GRBs, we find a strong correlation between the power-law fluence in the MeV and the LAT fluence (Pearson correlation: r = 0.88 and Spearman correlation: ρ = 0.81). We demonstrate that this correlation is not influenced by the correlation between the total and the power-law fluences at a confidence level of 2.3σ. We speculate the possible radiation mechanisms responsible for the correlation

Study of the artificial radioactivity of the marine medium using gamma spectrometry (1962-1966); Etude de la radioactivite artificielle du milieu marin par spectrometrie gamma (1962-1966)

Energy Technology Data Exchange (ETDEWEB)

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

1969-07-01

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) [French] Les resultats decrits dans cette etude concernent la radioactivite artificielle sous forme de zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 et praseodyme-144 apportee par la retombee atmospherique entre 1962 et 1964 et les

Study of the artificial radioactivity of the marine medium using gamma spectrometry (1962-1966); Etude de la radioactivite artificielle du milieu marin par spectrometrie gamma (1962-1966)

Energy Technology Data Exchange (ETDEWEB)

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

1969-07-01

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) [French] Les resultats decrits dans cette etude concernent la radioactivite artificielle sous forme de zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 et praseodyme-144 apportee par la retombee

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

Prompt radiation detectors to monitor target conditions

DEFF Research Database (Denmark)

Barnhart, T. E.; Engle, J. W.; Valdovinos, H. F.

2012-01-01

Lessons learned by basic scientists in the study of experimental nuclear physics can often go unnoticed by cyclotron operator’s intent on meeting a demanding schedule of tracer production. Prompt neutrons and gammas are the signature that the desired reaction is occurring, providing a robust meas...

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)

Calibration of A Prompt Gamma Neutron Activation Analysis (PGNAA) Facility: Experience at the Oregon State University TRIGA Reactor

International Nuclear Information System (INIS)

Norlida Yussup

2011-01-01

A prompt gamma neutron activation analysis (PGNAA) facility at Oregon State University (OSU) TRIGA reactor has been built in year 2008 and been operated since then. PGNAA is a technique used to determine the presence and quantity of trace elements such as boron, hydrogen and carbon which are more difficult to detect with other neutron analysis method. A calibration is essential to ensure the system works as required and the output is valid and reliable. The calibration was carried out by using Standard Reference Material (SRM). Besides, background data was also acquired for comparisons and analysis. The results are analyzed and discussed in this paper. (author)

A Preliminary Study on Detecting Fake Gold Bars Using Prompt Gamma Activation Analysis: Simulation of Neutron Transmission in Gold Bar

Energy Technology Data Exchange (ETDEWEB)

Lee, K. M.; Sun, G. M. [KAERI, Daejeon (Korea, Republic of)

2016-05-15

The purpose of this study is to develop fake gold bar detecting method by using Prompt-gamma activation analysis (PGAA) facility at the Korea Atomic Energy Research Institute (KAERI). PGAA is an established nuclear analytical technique for non-destructive determination of elemental and isotopic compositions. For a preliminary study on detecting fake gold bar, Monte Carlo simulation of neutron transmission in gold bar was conducted and the possibility for detecting fake gold bar was confirmed. Under the gold bullion standard, it guaranteed the government would redeem any amount of currency for its value in gold. After the gold bullion standard ended, gold bars have been the target for investment as ever. But it is well known that fake gold bar exist in the gold market. This cannot be identified easily without performing a testing as it has the same appearance as the pure gold bar. In order to avoid the trading of fake gold bar in the market, they should be monitored thoroughly. Although the transmissivity of cold neutrons are low comparing that of thermal neutrons, the slower neutrons are more apt to be absorbed in a target, and can increase the prompt gamma emission rate. Also the flux of both thermal and cold neutron beam is high enough to activate thick target. If the neutron beam is irradiated on the front and the reverse side of gold bar, all insides of it can be detected.

A Preliminary Study on Detecting Fake Gold Bars Using Prompt Gamma Activation Analysis: Simulation of Neutron Transmission in Gold Bar

International Nuclear Information System (INIS)

Lee, K. M.; Sun, G. M.

2016-01-01

The purpose of this study is to develop fake gold bar detecting method by using Prompt-gamma activation analysis (PGAA) facility at the Korea Atomic Energy Research Institute (KAERI). PGAA is an established nuclear analytical technique for non-destructive determination of elemental and isotopic compositions. For a preliminary study on detecting fake gold bar, Monte Carlo simulation of neutron transmission in gold bar was conducted and the possibility for detecting fake gold bar was confirmed. Under the gold bullion standard, it guaranteed the government would redeem any amount of currency for its value in gold. After the gold bullion standard ended, gold bars have been the target for investment as ever. But it is well known that fake gold bar exist in the gold market. This cannot be identified easily without performing a testing as it has the same appearance as the pure gold bar. In order to avoid the trading of fake gold bar in the market, they should be monitored thoroughly. Although the transmissivity of cold neutrons are low comparing that of thermal neutrons, the slower neutrons are more apt to be absorbed in a target, and can increase the prompt gamma emission rate. Also the flux of both thermal and cold neutron beam is high enough to activate thick target. If the neutron beam is irradiated on the front and the reverse side of gold bar, all insides of it can be detected

Characterization of high density SiPM non-linearity and energy resolution for prompt gamma imaging applications

Science.gov (United States)

Regazzoni, V.; Acerbi, F.; Cozzi, G.; Ferri, A.; Fiorini, C.; Paternoster, G.; Piemonte, C.; Rucatti, D.; Zappalà, G.; Zorzi, N.; Gola, A.

2017-07-01

Fondazione Bruno Kessler (FBK) (Trento, Italy) has recently introduced High Density (HD) and Ultra High-Density (UHD) SiPMs, featuring very small micro-cell pitch. The high cell density is a very important factor to improve the linearity of the SiPM in high-dynamic-range applications, such as the scintillation light readout in high-energy gamma-ray spectroscopy and in prompt gamma imaging for proton therapy. The energy resolution at high energies is a trade-off between the excess noise factor caused by the non-linearity of the SiPM and the photon detection efficiency of the detector. To study these effects, we developed a new setup that simulates the LYSO light emission in response to gamma photons up to 30 MeV, using a pulsed light source. We measured the non-linearity and energy resolution vs. energy of the FBK RGB-HD e RGB-UHD SiPM technologies. We considered five different cell sizes, ranging from 10 μm up to 25 μm. With the UHD technology we were able to observe a remarkable reduction of the SiPM non-linearity, less than 5% at 5 MeV with 10 μm cells, which should be compared to a non-linearity of 50% with 25 μm-cell HD-SiPMs. With the same setup, we also measured the different components of the energy resolution (intrinsic, statistical, detector and electronic noise) vs. cell size, over-voltage and energy and we separated the different sources of excess noise factor.

The Prompt-afterglow Connection in Gamma-ray Bursts: a Comprehensive Statistical Analysis of Swift X-ray Light-curves

Science.gov (United States)

Margutti, R.; Zaninoni, E.; Bernardini, M. G.; Chincarini, G.; Pasotti, F.; Guidorzi, C.; Angelini, Lorella; Burrows, D. N.; Capalbi, M.; Evans, P. A.;

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

Prompt-gamma neutron activation analysis for the non-destructive characterization of radioactive wastes; Prompt-Gamma-Neutronen-Aktivierungs-Analyse zur zerstoerungsfreien Charakterisierung radioaktiver Abfaelle

Energy Technology Data Exchange (ETDEWEB)

Kettler, John Paul Hermann

2010-07-01

In Germany, stringent official regulations govern the handling and final storage of radioactive waste. For this reason, the Federal Government has opted for final storage of radioactive waste with negligible heat generation in deep geological formations. At present the Konrad mine in Salzgitter will be rebuilt as a final disposal, the start of operation is scheduled for 2014. Radioactive waste with negligible heat generation originates from the operation and decommissioning of nuclear power plants, the medical sector or from research establishments. The requirements of the planning approval decision to build up the disposal Konrad, published on the 22{sup nd} of May 2002, obligate the waste producer to consider the limits for chemotoxic substances and to document the waste content. Before the radioactive waste can be stored in the final disposal, it is necessary to characterize the waste composition, relating to the concentration of water polluting substances. In particular for the wastes produced in the year before 1990, the so-called old wastes, there is a lack of documentation. The chemotoxicity of old wastes can mostly only characterized by time consuming and destructive methods. Furthermore these methods produce high costs, which depend on the arrangements to avoid contamination, to comply with the radiation protection and for the conditioning of the wastes. A prototype system, based on the Prompt-Gamma-Neutron-Activation-Analysis (PGNAA) with 14 MeV neutrons, has been developed in this work. This system allows the characterization of large samples, like 25 and 50 l drums. The signature of the element composition is in this processed by gamma-ray spectroscopy. This work was focused, in addition to the feasibility of the system, to the neutron and photon transport in large samples. Therefore the neutron and photon self-absorption in dependence of the sample composition were the main part of interest. Computer simulations (MCNP) and experiments were performed to

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

The Supercritical Pile Model: Prompt Emission Across the Electromagnetic Spectrum

Science.gov (United States)

Kazanas, Demos; Mastichiadis, A.

2008-01-01

The "Supercritical Pile" GRB model is an economical model that provides the dissipation necessary to convert explosively the energy stored in relativistic protons in the blast wave of a GRB into radiation; at the same time it produces spectra whose luminosity peaks at 1 MeV in the lab frame, the result of the kinematics of the proton-photon - pair production reaction that effects the conversion of proton energy to radiation. We outline the fundamental notions behind the "Supercritical Pile" model and discuss the resulting spectra of the prompt emission from optical to gamma-ray energies of order Gamma^2 m_ec^2, (Gamma is the Lorentz factor of the blast wave) present even in the absence of an accelerated particle distribution and compare our results to bursts that cover this entire energy range. Particular emphasis is given on the emission at the GLAST energy range both in the prompt and the afterglow stages of the burst.

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)

Prompt gamma-ray 3D-imaging for cultural heritage purposes

Energy Technology Data Exchange (ETDEWEB)

Schulze, Ralf

2010-07-01

The development of new, and the enhancement of existing element-sensitive imaging methods utilizing neutrons of different energy regions was the aim of the European ANCIENT CHARM project. During the present work the setup for Prompt Gamma-ray Activation Analysis (PGAA) at the research reactor FRM2 in Garching near Munich was modified to enable the spatial mapping of elemental abundances in the analysed samples. Because the PGAA setup at FRM2 was under construction at the beginning of the project first tests and the development of calibration and measurement procedures for the new imaging method were done by the PGAA group at the Budapest Research Reactor in cooperation with the Institute for Nuclear Physics of the University of Cologne. Due to the higher neutron flux at the PGAA setup at FRM2 the equipment was transferred from the Budapest Research Reactor to FRM2 after the PGAA setup at FRM2 started its regular operation. After further optimizations and the characterization of the setup, measurements were started on replicas of real archaeological objects before several measurements on real objects were performed and analysed. Several measurement configurations were applied. Additional to 2D and 3D imaging measurements a new application for the measurement of thin surface layers in the order of a few 100 {mu}m was developed. For the quantitative analysis of elemental distributions the exact knowledge of the neutron flux at each measured position in the analysed sample has to be known. Based on the well-established cold Neutron Tomography (NT) method a method and software have been developed, which enables the calculation of the neutron flux inside samples with the map of attenuation properties obtained through NT. A new data acquisition system was developed for the regular operation of the PGAA setup at FRM2, which supports traditional bulk PGAA measurements as well as measurements in the new imaging configuration. The high automation of the system allows a

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.

Six Years of Gamma Ray Burst Observations with BeppoSAX

OpenAIRE

Frontera, Filippo

2004-01-01

I give a summary of the prompt X-/gamma-ray detections of Gamma Ray Bursts (GRBs) with the BeppoSAX satellite and discuss some significant results obtained from the study of the prompt emission of these GRBs obtained with the BeppoSAX Gamma Ray Burst Monitor and Wide Field Cameras.

Analysis of minor elements in steel by coincidence method in deuteron-induced prompt gamma-ray emission (D-PIGE)

International Nuclear Information System (INIS)

Ene, Antoaneta; Popescu, I.; Badica, T.; Olariu, Agata; Besliu, C.

2000-01-01

Among the factors affecting the sensitivity of PIGE method (particle-induced prompt gamma-ray emission) frequently discussed in the literature, the background in the γ-ray spectrum holds a prominent place. In this work the limits of detection of minor elements in a standard steel sample (Euronorm rm No. 085/1) irradiated with 5 MeV deuterons have been determined by the regular d-PIGE method and with the selection of the (d,n) reaction channel by measuring γ--n coincidences following the reaction steel + deuterons. This approach has resulted in a significant improvement of the sensitivity of the analysis, reducing the background in prompt gamma ray spectrum by eliminating the γ--rays observed in the singular spectrum which arises from the reaction channels (d, d'), (d, γ), (d, p), (d, 3 He), (d, α) and (d, t). From the singular spectrum we could establish the presence of the elements S, Pb, Mo, Co, V, P, O, Si, Zn, Mn, Cu, Sb, C, Al, N, As, Ti and Fe. The γ--n coincidence spectrum, obtained as a result of the selection of the γ- transitions via the reaction channel (d, n), is substantially different from the singular γ--spectrum, exhibiting γ- lines of rather high intensity to be used in the analyses on a reduced background. The coincidence spectrum shows lines from S, Mo, Co, Zn, Si, Mn, V, Sb, Ti, As, Ni, Cr, P, O, Al, Cu and Fe. We also made a comparative study with the published results using 5.5 MeV protons as projectiles. While for a given energy of the protons not all the elements of interest lead to a (p, n) reaction (C, O, P, S, Si etc.), most of the (d, n) reactions are exoergic. On the other side, the identification of the elements is more difficult in the case of deuterons. (authors)

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)

Prompt gamma-ray analysis of archaeological bronze

International Nuclear Information System (INIS)

Oura, Y.; Saito, A.; Sueki, K.; Nakahara, H.; Tomizawa, T.; Nishikawa, T.; Yonezawa, C.; Matsue, H.; Sawahata, H.

1999-01-01

Prompt γ-ray analysis using the internal monostandard method was applied to voluminous archaeological bronze mirrors produced in ancient China. Sn/Cu content ratios were determined nondestructively by this method. Furthermore, Au/Cu, As/Cu, and Sb/Cu content ratios were determined by means of measuring decay γ-rays emitted from radioactive nuclides produced within samples via (n,γ) reactions. It is clear that the Sn/Cu content ratios in bronze mirrors produced in the Sung era is smaller than in ones produced in between the Han and the Tung era. (author)

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)

PANCHROMATIC OBSERVATIONS OF THE TEXTBOOK GRB 110205A: CONSTRAINING PHYSICAL MECHANISMS OF PROMPT EMISSION AND AFTERGLOW

Energy Technology Data Exchange (ETDEWEB)

Zheng, W. [Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI 48109 (United States); Shen, R. F. [Department of Astronomy and Astrophysics, University of Toronto, Toronto, Ontario M5S 3H4 (Canada); Sakamoto, T. [Center for Research and Exploration in Space Science and Technology (CRESST), NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Beardmore, A. P. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); De Pasquale, M. [Mullard Space Science Laboratory, University College London, Holmbury Road, Holmbury St. Mary, Dorking RH5 6NT (United Kingdom); Wu, X. F.; Zhang, B. [Department of Physics and Astronomy, University of Nevada Las Vegas, Las Vegas, NV 89154 (United States); Gorosabel, J. [Instituto de Astrofisica de Andalucia (IAA-CSIC), 18008 Granada (Spain); Urata, Y. [Institute of Astronomy, National Central University, Chung-Li 32054, Taiwan (China); Sugita, S. [EcoTopia Science Institute, Nagoya University, Furo-cho, chikusa, Nagoya 464-8603 (Japan); Pozanenko, A. [Space Research Institute (IKI), 84/32 Profsoyuznaya St., Moscow 117997 (Russian Federation); Nissinen, M. [Taurus Hill Observatory, Haerkaemaeentie 88, 79480 Kangaslampi (Finland); Sahu, D. K. [CREST, Indian Institute of Astrophysics, Koramangala, Bangalore 560034 (India); Im, M. [Center for the Exploration of the Origin of the Universe, Department of Physics and Astronomy, FPRD, Seoul National University, Shillim-dong, San 56-1, Kwanak-gu, Seoul (Korea, Republic of); Ukwatta, T. N. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Andreev, M. [Terskol Branch of Institute of Astronomy of RAS, Kabardino-Balkaria Republic 361605 (Russian Federation); Klunko, E., E-mail: zwk@umich.edu, E-mail: rfshen@astro.utoronto.ca, E-mail: zhang@physics.unlv.edu [Institute of Solar-Terrestrial Physics, Lermontov St., 126a, Irkutsk 664033 (Russian Federation); and others

2012-06-01

We present a comprehensive analysis of a bright, long-duration (T{sub 90} {approx} 257 s) GRB 110205A at redshift z = 2.22. The optical prompt emission was detected by Swift/UVOT, ROTSE-IIIb, and BOOTES telescopes when the gamma-ray burst (GRB) was still radiating in the {gamma}-ray band, with optical light curve showing correlation with {gamma}-ray data. Nearly 200 s of observations were obtained simultaneously from optical, X-ray, to {gamma}-ray (1 eV to 5 MeV), which makes it one of the exceptional cases to study the broadband spectral energy distribution during the prompt emission phase. In particular, we clearly identify, for the first time, an interesting two-break energy spectrum, roughly consistent with the standard synchrotron emission model in the fast cooling regime. Shortly after prompt emission ({approx}1100 s), a bright (R = 14.0) optical emission hump with very steep rise ({alpha} {approx} 5.5) was observed, which we interpret as the reverse shock (RS) emission. It is the first time that the rising phase of an RS component has been closely observed. The full optical and X-ray afterglow light curves can be interpreted within the standard reverse shock (RS) + forward shock (FS) model. In general, the high-quality prompt and afterglow data allow us to apply the standard fireball model to extract valuable information, including the radiation mechanism (synchrotron), radius of prompt emission (R{sub GRB} {approx} 3 Multiplication-Sign 10{sup 13} cm), initial Lorentz factor of the outflow ({Gamma}{sub 0} {approx} 250), the composition of the ejecta (mildly magnetized), the collimation angle, and the total energy budget.

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)

A low-count reconstruction algorithm for Compton-based prompt gamma imaging

Science.gov (United States)

Huang, Hsuan-Ming; Liu, Chih-Chieh; Jan, Meei-Ling; Lee, Ming-Wei

2018-04-01

The Compton camera is an imaging device which has been proposed to detect prompt gammas (PGs) produced by proton–nuclear interactions within tissue during proton beam irradiation. Compton-based PG imaging has been developed to verify proton ranges because PG rays, particularly characteristic ones, have strong correlations with the distribution of the proton dose. However, accurate image reconstruction from characteristic PGs is challenging because the detector efficiency and resolution are generally low. Our previous study showed that point spread functions can be incorporated into the reconstruction process to improve image resolution. In this study, we proposed a low-count reconstruction algorithm to improve the image quality of a characteristic PG emission by pooling information from other characteristic PG emissions. PGs were simulated from a proton beam irradiated on a water phantom, and a two-stage Compton camera was used for PG detection. The results show that the image quality of the reconstructed characteristic PG emission is improved with our proposed method in contrast to the standard reconstruction method using events from only one characteristic PG emission. For the 4.44 MeV PG rays, both methods can be used to predict the positions of the peak and the distal falloff with a mean accuracy of 2 mm. Moreover, only the proposed method can improve the estimated positions of the peak and the distal falloff of 5.25 MeV PG rays, and a mean accuracy of 2 mm can be reached.

A Calibration to Predict Concentrations of Impurities in Plutonium Oxide by Prompt Gamma Analysis

International Nuclear Information System (INIS)

Narlesky, J.E.; Kelly, E.J.; Foster, L.A.

2005-01-01

Prompt gamma (PG) analysis has been used to identify the presence of certain impurities in plutonium oxide, which has been stored in 3013 containers. A regression analysis was used to evaluate the trends between the count rates obtained from PG analysis and the concentration of the impurities in plutonium oxide samples measured by analytical chemistry techniques. The results of the analysis were used to obtain calibration curves, which may be used to predict the concentration of Al, Be, Cl, F, Mg, and Na in the 3013 containers. The scatter observed in the data resulted from several factors including sample geometry, error in sampling for chemical assay, statistical counting error, and intimacy of mixing of impurities and plutonium. Standards prepared by mixing plutonium oxide with CaF 2 , NaCl, and KCl show that intimacy mixing and sampling error have the largest influence on the results. Although these factors are difficult to control, the calibrations are expected to yield semiquantitative results that are sufficient for the purpose of ordering or ranking

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)

Vertical distribution of elements in non-polluted estuarine sediments determined by neutron induced prompt gamma-ray and instrumental neutron activation analyses

International Nuclear Information System (INIS)

Kuno, A.; Sampei, K.; Matsuo, M.; Sawahata, H.

1999-01-01

Neutron induced prompt gamma-ray analysis (PGA) and instrumental neutron activation analysis (INAA) have been applied to the sediments collected from the Yasaka River estuary in Oita Prefecture, Japan. The vertical distribution of 33 elements in the sediments has been determined and compared with that in more polluted estuarine sediments. While the S content increased with increasing depth because of a sulphide accumulation under reducing condition, the increase in sulphide-forming elements such as Ag, Cd, Co and Zn was not observed in the deeper section of the Yasaka River estuarine sediments. (author)

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

Multidimensional gamma-ray spectrometry is a new technique for the measurement of radionuclides which has special application in biology. This instrumental technique allows direct identification and measurement of individual gamma-ray emitters in complex mixtures of radionuclides in diverse sample matrices without prior chemical treatment. The detector system is designed to provide: high sensitivity through use of two large (6-in diam., 4-in thick) Nal(Tl) detectors; high selectivity by using coincidence counting techniques which separate gamma ray spectra by taking advantage of the gamma-ray decay characteristics of each radionuclide ; and ultra-low background and reduced Compton interference through a surrounding anticoincidence annulus detector (a NaI(Tl) crystal 11 Vulgar-Fraction-One-Half -in thick with a 6 Vulgar-Fraction-One-Half - in - diam. hole). A 4096-channel multidimensional analyser analyses the two gamma-rays in coincidence according to their energies and stores them in the plane of the 64 X 64-channel memory while non-coincident events are stored only on the axes of the memory. This effectively decreases the background and Compton interference by orders of magnitude while greatly improving the selectivity. Direct gamma-ray spectrometric measurement of trace levels of radionuclides in biological samples has been inhibited by the presence of relatively large amounts of natural 4 Degree-Sign K whose 1.47 MeV gamma-radiation has interfered with their measurement. Since most radionuclides decay through emission of two or more gamma-rays in cascade the new technique does provide a direct selective measurement and permits wider application. For example, {sup 22}Na (a naturally occurring cosmic-ray produced radionuclide), {sup 134}Cs and {sup 137}Cs (fission products) can be readily measured at existing levels (in some cases at less than 1 dpmAg) in meat, fish, foodstuffs, as well as in urine, so that uptake-excretion studies are possible. This technique

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)

Comment on 'Imaging of prompt gamma rays emitted during delivery of clinical proton beams with a Compton camera: feasibility studies for range verification'.

Science.gov (United States)

Sitek, Arkadiusz

2016-12-21

The origin ensemble (OE) algorithm is a new method used for image reconstruction from nuclear tomographic data. The main advantage of this algorithm is the ease of implementation for complex tomographic models and the sound statistical theory. In this comment, the author provides the basics of the statistical interpretation of OE and gives suggestions for the improvement of the algorithm in the application to prompt gamma imaging as described in Polf et al (2015 Phys. Med. Biol. 60 7085).

Utilisation of prompt fission neutron technology in Greenfields uranium exploration

International Nuclear Information System (INIS)

Mutz, P.R.

2007-01-01

Conventionally, gamma detection technology has been used in uranium exploration programs for the initial detection of uranium as well as for a determination of uranium concentration. Geophysical logging companies use wireline gamma probes to measure uranium within boreholes, and field technicians utilise hand held gamma meters to detect uranium in rock samples, drill cuttings and cores. Borehole geophysical logging equipment typically records the uranium concentration as %eU 3 O8, where e represents an equivalent determination of uranium concentration as opposed to a laboratory assay. This method of uranium determination is an indirect method, as it measures gamma radiation from uranium-238 (U-238) isotope decay chain progeny; principally the bismuth-214 (Bi-214) isotope. Consequently, the uranium determination can be inaccurate due to natural disequilibrium between the U-238 parent and the decay chain progeny. This is especially true in sedimentary hosted uranium deposits, where the uranium and daughter progeny may have been geochemically separated. The gamma detection method for uranium can also be rendered inaccurate by detecting the gamma signature from potassium in clays as well as from thorium; both of which can provide a false (enhanced) eU 3 O8 determination. Prompt Fission Neutron (PFN) technology is a geophysical wireline logging technology used in the same manner as conventional gamma logging. The difference is that PFN provides a direct determination of uranium within a borehole, irrespective of natural disequilibrium or the presence of other radioactive elements. This paper provides a brief description of natural uranium and radioactivity as a basis for explaining the conventional use of gamma radiation detectors for the detection and determination of uranium concentration in exploration boreholes, including the potential pitfalls of this technology. A detailed description of prompt fission neutron technology is also presented, along with a discussion

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)

On the accuracy of protein determination in large biological samples by prompt gamma neutron activation analysis

International Nuclear Information System (INIS)

Kasviki, K.; Stamatelatos, I.E.; Yannakopoulou, E.; Papadopoulou, P.; Kalef-Ezra, J.

2007-01-01

A prompt gamma neutron activation analysis (PGNAA) facility has been developed for the determination of nitrogen and thus total protein in large volume biological samples or the whole body of small animals. In the present work, the accuracy of nitrogen determination by PGNAA in phantoms of known composition as well as in four raw ground meat samples of about 1 kg mass was examined. Dumas combustion and Kjeldahl techniques were also used for the assessment of nitrogen concentration in the meat samples. No statistically significant differences were found between the concentrations assessed by the three techniques. The results of this work demonstrate the applicability of PGNAA for the assessment of total protein in biological samples of 0.25-1.5 kg mass, such as a meat sample or the body of small animal even in vivo with an equivalent radiation dose of about 40 mSv

On the accuracy of protein determination in large biological samples by prompt gamma neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Kasviki, K. [Institute of Nuclear Technology and Radiation Protection, NCSR ' Demokritos' , Aghia Paraskevi, Attikis 15310 (Greece); Medical Physics Laboratory, Medical School, University of Ioannina, Ioannina 45110 (Greece); Stamatelatos, I.E. [Institute of Nuclear Technology and Radiation Protection, NCSR ' Demokritos' , Aghia Paraskevi, Attikis 15310 (Greece)], E-mail: ion@ipta.demokritos.gr; Yannakopoulou, E. [Institute of Physical Chemistry, NCSR ' Demokritos' , Aghia Paraskevi, Attikis 15310 (Greece); Papadopoulou, P. [Institute of Technology of Agricultural Products, NAGREF, Lycovrissi, Attikis 14123 (Greece); Kalef-Ezra, J. [Medical Physics Laboratory, Medical School, University of Ioannina, Ioannina 45110 (Greece)

2007-10-15

A prompt gamma neutron activation analysis (PGNAA) facility has been developed for the determination of nitrogen and thus total protein in large volume biological samples or the whole body of small animals. In the present work, the accuracy of nitrogen determination by PGNAA in phantoms of known composition as well as in four raw ground meat samples of about 1 kg mass was examined. Dumas combustion and Kjeldahl techniques were also used for the assessment of nitrogen concentration in the meat samples. No statistically significant differences were found between the concentrations assessed by the three techniques. The results of this work demonstrate the applicability of PGNAA for the assessment of total protein in biological samples of 0.25-1.5 kg mass, such as a meat sample or the body of small animal even in vivo with an equivalent radiation dose of about 40 mSv.

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

Science.gov (United States)

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

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

Machine learning-based patient specific prompt-gamma dose monitoring in proton therapy

Science.gov (United States)

Gueth, P.; Dauvergne, D.; Freud, N.; Létang, J. M.; Ray, C.; Testa, E.; Sarrut, D.

2013-07-01

Online dose monitoring in proton therapy is currently being investigated with prompt-gamma (PG) devices. PG emission was shown to be correlated with dose deposition. This relationship is mostly unknown under real conditions. We propose a machine learning approach based on simulations to create optimized treatment-specific classifiers that detect discrepancies between planned and delivered dose. Simulations were performed with the Monte-Carlo platform Gate/Geant4 for a spot-scanning proton therapy treatment and a PG camera prototype currently under investigation. The method first builds a learning set of perturbed situations corresponding to a range of patient translation. This set is then used to train a combined classifier using distal falloff and registered correlation measures. Classifier performances were evaluated using receiver operating characteristic curves and maximum associated specificity and sensitivity. A leave-one-out study showed that it is possible to detect discrepancies of 5 mm with specificity and sensitivity of 85% whereas using only distal falloff decreases the sensitivity down to 77% on the same data set. The proposed method could help to evaluate performance and to optimize the design of PG monitoring devices. It is generic: other learning sets of deviations, other measures and other types of classifiers could be studied to potentially reach better performance. At the moment, the main limitation lies in the computation time needed to perform the simulations.

Machine learning-based patient specific prompt-gamma dose monitoring in proton therapy

International Nuclear Information System (INIS)

Gueth, P; Freud, N; Létang, J M; Sarrut, D; Dauvergne, D; Ray, C; Testa, E

2013-01-01

Online dose monitoring in proton therapy is currently being investigated with prompt-gamma (PG) devices. PG emission was shown to be correlated with dose deposition. This relationship is mostly unknown under real conditions. We propose a machine learning approach based on simulations to create optimized treatment-specific classifiers that detect discrepancies between planned and delivered dose. Simulations were performed with the Monte-Carlo platform Gate/Geant4 for a spot-scanning proton therapy treatment and a PG camera prototype currently under investigation. The method first builds a learning set of perturbed situations corresponding to a range of patient translation. This set is then used to train a combined classifier using distal falloff and registered correlation measures. Classifier performances were evaluated using receiver operating characteristic curves and maximum associated specificity and sensitivity. A leave-one-out study showed that it is possible to detect discrepancies of 5 mm with specificity and sensitivity of 85% whereas using only distal falloff decreases the sensitivity down to 77% on the same data set. The proposed method could help to evaluate performance and to optimize the design of PG monitoring devices. It is generic: other learning sets of deviations, other measures and other types of classifiers could be studied to potentially reach better performance. At the moment, the main limitation lies in the computation time needed to perform the simulations. (paper)

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)

Prompt gamma-ray 3D-imaging for cultural heritage purposes

Energy Technology Data Exchange (ETDEWEB)

Schulze, Ralf

2010-07-01

The development of new, and the enhancement of existing element-sensitive imaging methods utilizing neutrons of different energy regions was the aim of the European ANCIENT CHARM project. During the present work the setup for Prompt Gamma-ray Activation Analysis (PGAA) at the research reactor FRM2 in Garching near Munich was modified to enable the spatial mapping of elemental abundances in the analysed samples. Because the PGAA setup at FRM2 was under construction at the beginning of the project first tests and the development of calibration and measurement procedures for the new imaging method were done by the PGAA group at the Budapest Research Reactor in cooperation with the Institute for Nuclear Physics of the University of Cologne. Due to the higher neutron flux at the PGAA setup at FRM2 the equipment was transferred from the Budapest Research Reactor to FRM2 after the PGAA setup at FRM2 started its regular operation. After further optimizations and the characterization of the setup, measurements were started on replicas of real archaeological objects before several measurements on real objects were performed and analysed. Several measurement configurations were applied. Additional to 2D and 3D imaging measurements a new application for the measurement of thin surface layers in the order of a few 100 {mu}m was developed. For the quantitative analysis of elemental distributions the exact knowledge of the neutron flux at each measured position in the analysed sample has to be known. Based on the well-established cold Neutron Tomography (NT) method a method and software have been developed, which enables the calculation of the neutron flux inside samples with the map of attenuation properties obtained through NT. A new data acquisition system was developed for the regular operation of the PGAA setup at FRM2, which supports traditional bulk PGAA measurements as well as measurements in the new imaging configuration. The high automation of the system allows a

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.)

Determination of boron in ceramic reference materials by prompt gamma activation analysis using focused neutron guided beam of JRR-3M

International Nuclear Information System (INIS)

Miura, T.; Kuroiwa, T.; Chiba, K.; Matsue, H.

2008-01-01

Prompt gamma activation analysis using a focused thermal neutron guided beam at JAEA JRR-3M was applied to the determination of B in ceramic certified reference materials (BAM CRM S-003 Silicon Carbide Powder and NMIJ CRM 8004-a Silicon Nitride Powder). Cl and Si were used as internal standards to obtain linear calibration curves of B. The analytical result of B in BAM CRM S-003 was in good agreement with the certified value. The relative expanded measurement uncertainties (k = 2) were 4.8% for BAM CRM S-003 and 4.9% for NMIJ CRM 8004-a. (author)

Application of the Monte Carlo technique to the study of radiation transport in a prompt gamma in vivo neutron activation system

International Nuclear Information System (INIS)

Chan, A.A.; Beddoe, A.H.

1985-01-01

A Monte Carlo code (MORSE-SGC) from the Radiation Shielding Information Centre at Oak Ridge National Laboratory, USA, has been adapted and used to model radiation transport in the Auckland prompt gamma in vivo neutron activation analysis facility. Preliminary results are presented for the slow neutron flux in an anthropomorphic phantom which are in broad agreement with those obtained by measurement via activation foils. Since experimental optimization is not logistically feasible and since theoretical optimization of neutron activation facilities has not previously been attempted, it is hoped that the Monte Carlo calculations can be used to provide a basis for improved system design

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)

Comment on ‘Imaging of prompt gamma rays emitted during delivery of clinical proton beams with a Compton camera: feasibility studies for range verification’

Science.gov (United States)

Sitek, Arkadiusz

2016-12-01

The origin ensemble (OE) algorithm is a new method used for image reconstruction from nuclear tomographic data. The main advantage of this algorithm is the ease of implementation for complex tomographic models and the sound statistical theory. In this comment, the author provides the basics of the statistical interpretation of OE and gives suggestions for the improvement of the algorithm in the application to prompt gamma imaging as described in Polf et al (2015 Phys. Med. Biol. 60 7085).

Prompt gamma-ray activation technique for in-situ analysis of mercury pollution in water

International Nuclear Information System (INIS)

Khouri, M.C.; Jayanthi, K.A.; Pascholati, P.R.

1995-01-01

Industrial and mining pollutants discharged into water are in general distributed homogeneously and we investigated a prompt neutron activation technique for the in-situ analysis, to start with of Hg content in water. The laboratory test employed a 252 Cf neutron source (of ∼ 3 x 10 6 n/s fluence) submerged in a test tank of water of ∼ 500 litres, and to monitor the gamma-ray emission a 4 x 4 NaI (Tl) detector system was employed. In 3000 is time interval trials, for a 46 ppm contamination level of Hg, we observed an excess of counts of ∼ 9.2 σ significance in the energy range of 4000-6500 keV, which can be attributed to the presence of mercury. This test system for a 10 hour monitoring can provide a minimum detectable sensitivity at 4.78 ppm. In the future experiments, we propose to replace the NaI(Tl) detector by a HPGe detector to facilitate simultaneous analyses of pollutants such as cadmium, chlorine, chromium etc for detection at few tenths to tens of ppm levels or better. (author). 5 refs., 2 figs., 2 tabs

Prompt dipole gamma-ray emission in fusionlike heavy-ion reactions

CERN Document Server

Pierroutsakou, D; Di Pietro, M; Mordente, R; Ordine, A; Romoli, M; De Rosa, A; Inglima, G; La Commara, M; Martin, B; Roca, V; Sandoli, M; Trotta, M; Vardaci, E; Ming, R; Rizzo, F; Soramel, F; Stroe, L

2003-01-01

The sup 3 sup 2 S+ sup 1 sup 0 sup 0 Mo and sup 3 sup 6 S+ sup 9 sup 6 Mo fusionlike reactions were studied at incident energy of E sub l sub a sub b =298 MeV and 320 MeV, respectively, with the aim of probing the influence of the entrance channel charge asymmetry on the dipole gamma-ray emission. The excitation energy and spin distribution of the compound nucleus created in these reactions were identical, the only difference being associated with the unequal charge asymmetry of the two entrance channels. High-energy gamma-rays were detected in an array of 9 seven-pack BaF sub 2 clusters. Coincidence with fusionlike residues detected in four PPAC ensured the selection of central reaction events. By studying the differential gamma-ray multiplicity associated with the two reactions it was shown that the dipole strength excited in the compound nucleus increases with the entrance channel charge asymmetry. From the linearized spectra, the increase of the GDR gamma-ray intensity was found to be propor to 25% for th...

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,

Photospheric Emission in the Joint GBM and Konus Prompt Spectra of GRB 120323A

Energy Technology Data Exchange (ETDEWEB)

Guiriec, S.; Kouveliotou, C. [Department of Physics, The George Washington University, 725 21st Street NW, Washington, DC 20052 (United States); Gehrels, N.; McEnery, J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Hartmann, D. H., E-mail: sylvain.guiriec@nasa.gov [Department of Physics and Astronomy, Clemson University, Kinard Lab of Physics (United States)

2017-09-10

GRB 120323A is a very intense short gamma -ray burst (GRB) detected simultaneously during its prompt γ -ray emission phase with the Gamma-ray Burst Monitor (GBM) on board the Fermi Gamma-ray Space Telescope and the Konus experiment on board the Wind satellite. GBM and Konus operate in the keV–MeV regime; however, the GBM range is broader toward both the low and the high parts of the γ -ray spectrum. Analyses of such bright events provide a unique opportunity to check the consistency of the data analysis as well as cross-calibrate the two instruments. We performed time-integrated and coarse time-resolved spectral analysis of GRB 120323A prompt emission. We conclude that the analyses of GBM and Konus data are only consistent when using a double-hump spectral shape for both data sets; in contrast, the single hump of the empirical Band function, traditionally used to fit GRB prompt emission spectra, leads to significant discrepancies between GBM and Konus analysis results. Our two-hump model is a combination of a thermal-like and a non-thermal component. We interpret the first component as a natural manifestation of the jet photospheric emission.

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.

Critical concentrations of cadmium in human liver and kidney measured by prompt-gamma neutron activation

International Nuclear Information System (INIS)

Cohn, S.H.; Vartsky, D.; Yasumura, S.; Zanzi, I.; Ellis, K.J.

1979-01-01

Few data exist on Cd metabolism in human beings. In particular, data are needed on the role of parameters such as age, sex, weight, diet, smoking habits, and state of health. Prompt-gamma neutron activation analysis (PGNAA) provides the only currently available means for measuring in vivo levels of liver and kidney Cd. The method employs an 85 Ci, 235 Pu,Be neutron source and a gamma ray detection system consisting of two Ge(Li) detector. The dose delivered to the liver and left kidney is 666 mrem (detection limit is 1.4 μg/g Cd in the liver and 2.0 mg Cd for one kidney). Absolute levels of Cd in the kidney and concentrations of Cd in the liver were measured in vivo in twenty healthy adult males using 238 Pu,Be neutron sources. Organ Cd levels of smokers were significantly elevated above those of nonsmokers. Biological half-time for Cd in the body was estimated to be 15.7 yr. Cigarette smoking was estimated to result in the absorption of 1.9 μg of Cd per pack. No relationship was bound between body stores of Cd (liver and kidney) and Cd or β-microglobulin levels in urine and blood. Currently the above neutron activation facility is being mounted on a 34-ft mobile trailer unit. This unit will be used to monitor levels of Cd in industrial workers. It is anticipated that critically important data, particularly on industrially exposed workers, will provide a better basis for determining critical concentrations and for the setting or revision of standards for industrial and environmental Cd pollution

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

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

The detection of gamma-emitting radionuclides at environmental levels in biological media requires that the sensitivity of the counting system be high. To accumulate sufficiently precise data, it is often necessary to count samples for long periods of time - from one to several hours. The most efficient utilization of expensive low-background gamma-ray spectrometric counting equipment requires that it be operated on a continuous basis. This necessitates either the continuous presence of personnel or a completely automated system, including the changing of samples and recording of data. The purpose of this paper is to describe the automated gamma-ray spectrometry counting system designed, built and in use at the Northeastern Radiological Health Laboratory, Winchester, Massachusetts. The sample changing unit was designed to operate in conjunction with a large steel shield, any commercial unit with a front opening door being readily adaptable for this purpose. The changer is equipped to handle a variety of samples including biological and medical types. The unit consists of a revolving tray with a capacity for sixteen samples, an indexing system for positioning the samples, a mechanical arm with an attached electromagnet for inserting and removing the samples from the shield, and a lever for opening and closing the shield door. The changer has been completely integrated with a multichannel analyser with the provision of safety features to interrupt the cycle in case of malfunction at any step. After a preset counting period, the data are punched onto paper tape and processed by an IBM. 1620 computer. The first model of the sample changer, for which a patent is pending, has been in operation at the Northeastern Radiological Health Laboratory for about one year. During that time, it has been used extensively and has proven completely satisfactory. The total cost of the unit, including labour, was less than $ 2000. (author) [French] GAMMAPour deceler les radionucleides

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

LIMITS ON OPTICAL POLARIZATION DURING THE PROMPT PHASE OF GRB 140430A

Energy Technology Data Exchange (ETDEWEB)

Kopac, D.; Mundell, C. G.; Arnold, D. M.; Steele, I. A.; Kobayashi, S.; Lamb, G. P.; Smith, R. J.; Virgili, F. J. [Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool, L3 5RF (United Kingdom); Japelj, J.; Gomboc, A. [Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana (Slovenia); Guidorzi, C.; Dichiara, S. [Department of Physics and Earth Sciences, University of Ferrara, via Saragat 1, I-44122, Ferrara (Italy); Harrison, R. M. [Department of Astrophysics, School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv (Israel); Melandri, A. [INAF—Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate (Italy); Castro-Tirado, A. J.; Gorosabel, J.; Sánchez-Ramírez, R.; Oates, S. R. [Instituto de Astrofísica de Andalucía (IAA-CSIC), Glorieta de la Astronomia s/n, E-18008 Granada (Spain); Järvinen, A. [AIP—Leibniz-Institut für Astrophysik Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany); Jelínek, M., E-mail: drejc.kopac@fmf.uni-lj.si [ASU-CAS—Astronomical Institute of the Czech Academy of Sciences, Fričova 298, 251 65 Ondřejov (Czech Republic)

2015-11-01

Gamma-ray burst GRB 140430A was detected by the Swift satellite and observed promptly with the imaging polarimeter RINGO3 mounted on the Liverpool Telescope, with observations beginning while the prompt γ-ray emission was still ongoing. In this paper, we present densely sampled (10-s temporal resolution) early optical light curves (LCs) in 3 optical bands and limits to the degree of optical polarization. We compare optical, X-ray, and gamma-ray properties and present an analysis of the optical emission during a period of high-energy flaring. The complex optical LC cannot be explained merely with a combination of forward and reverse shock emission from a standard external shock, implying additional contribution of emission from internal shock dissipation. We estimate an upper limit for time averaged optical polarization during the prompt phase to be as low as P < 12% (1σ). This suggests that the optical flares and early afterglow emission in this GRB are not highly polarized. Alternatively, time averaging could mask the presence of otherwise polarized components of distinct origin at different polarization position angles.

LIMITS ON OPTICAL POLARIZATION DURING THE PROMPT PHASE OF GRB 140430A

International Nuclear Information System (INIS)

Kopac, D.; Mundell, C. G.; Arnold, D. M.; Steele, I. A.; Kobayashi, S.; Lamb, G. P.; Smith, R. J.; Virgili, F. J.; Japelj, J.; Gomboc, A.; Guidorzi, C.; Dichiara, S.; Harrison, R. M.; Melandri, A.; Castro-Tirado, A. J.; Gorosabel, J.; Sánchez-Ramírez, R.; Oates, S. R.; Järvinen, A.; Jelínek, M.

2015-01-01

Gamma-ray burst GRB 140430A was detected by the Swift satellite and observed promptly with the imaging polarimeter RINGO3 mounted on the Liverpool Telescope, with observations beginning while the prompt γ-ray emission was still ongoing. In this paper, we present densely sampled (10-s temporal resolution) early optical light curves (LCs) in 3 optical bands and limits to the degree of optical polarization. We compare optical, X-ray, and gamma-ray properties and present an analysis of the optical emission during a period of high-energy flaring. The complex optical LC cannot be explained merely with a combination of forward and reverse shock emission from a standard external shock, implying additional contribution of emission from internal shock dissipation. We estimate an upper limit for time averaged optical polarization during the prompt phase to be as low as P < 12% (1σ). This suggests that the optical flares and early afterglow emission in this GRB are not highly polarized. Alternatively, time averaging could mask the presence of otherwise polarized components of distinct origin at different polarization position angles

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.

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

Design study of a Compton camera for prompts-gamma imaging during ion beam therapy

International Nuclear Information System (INIS)

Richard, Marie-Helene

2012-01-01

Ion beam therapy is an innovative radiotherapy technique using mainly carbon ion and proton irradiations. Its aim is to improve the current treatment modalities. Because of the sharpness of the dose distributions, a control of the dose if possible in real time is highly desirable. A possibility is to detect the prompt gamma rays emitted subsequently to the nuclear fragmentations occurring during the treatment of the patient. In a first time two different Compton cameras (double and single scattering) have been optimised by means of Monte Carlo simulations. The response of the camera to a photon point source with a realistic energy spectrum was studied. Then, the response of the camera to the irradiation of a water phantom by a proton beam was simulated. It was first compared with measurement performed with small-size detectors. Then, using the previous measurements, we evaluated the counting rates expected in clinical conditions. In the current set-up of the camera, these counting rates are pretty high. Pile up and random coincidences will be problematic. Finally we demonstrate that the detection system is capable to detect a longitudinal shift in the Bragg peak of ± 5 mm, even with the current reconstruction algorithm. (author)

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.

OBSERVATIONAL SIGNATURES OF SUB-PHOTOSPHERIC RADIATION-MEDIATED SHOCKS IN THE PROMPT PHASE OF GAMMA-RAY BURSTS

International Nuclear Information System (INIS)

Levinson, Amir

2012-01-01

A shock that forms below the photosphere of a gamma-ray burst (GRB) outflow is mediated by Compton scattering of radiation advected into the shock by the upstream fluid. The characteristic scale of such a shock, a few Thomson depths, is larger than any kinetic scale involved by several orders of magnitude. Hence, unlike collisionless shocks, radiation-mediated shocks cannot accelerate particles to nonthermal energies. The spectrum emitted by a shock that emerges from the photosphere of a GRB jet reflects the temperature profile downstream of the shock, with a possible contribution at the highest energies from the shock transition layer itself. We study the properties of radiation-mediated shocks that form during the prompt phase of GRBs and compute the time-integrated spectrum emitted by the shocked fluid following shock breakout. We show that the time-integrated emission from a single shock exhibits a prominent thermal peak, with the location of the peak depending on the shock velocity profile. We also point out that multiple shock emission can produce a spectrum that mimics a Band spectrum.

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)

Pulsed neutron uranium borehole logging with prompt fission neutrons

International Nuclear Information System (INIS)

Bivens, H.M.; Smith, G.W.; Jensen, D.H.

1976-01-01

The gross count natural gamma log normally used for uranium borehole logging is seriously affected by disequilibrium. Methods for the direct measurement of uranium, such as neutron logging, which are not affected by disequilibrium have been the object of considerable effort in recent years. This paper describes a logging system for uranium which uses a small accelerator to generate pulses of 14 MeV neutrons to detect and assay uranium by the measurement of prompt fission neutrons in the epithermal energy range. After an initial feasibility study, a prototype logging probe was built for field evaluation which began in January 1976. Physical and operational characteristics of the prototype probe, the neutron tube-transformer assembly, and the neutron tube are described. In logging operations, only the epithermal prompt fission neutrons detected between 250 microseconds to 2500 microseconds following the excitation neutron pulse are counted. Comparison of corrected neutron logs with the conventional gross count natural gamma logs and the chemical assays of cores from boreholes are shown. The results obtained with this neutron probe clearly demonstrate its advantages over the gross count natural gamma log, although at this time the accuracy of the neutron log assay is not satisfactory under some conditions. The necessary correction factors for various borehole and formation parameters are being determined and, when applied, should improve the assay accuracy