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Sample records for situ gamma spectrometry

  1. 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...

  2. 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)

  3. Theory of in situ gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Balea, G.

    2002-01-01

    The technique of in situ spectrometry had its origin during the time of atmospheric nuclear weapons testing when is was found to provide quick, reliable information on the components of the outdoor environment. It provided a means to separate natural background from man-made sources and gave quantitative results. Over the years, it has been employed by various groups for assessing radiation sources in the environment not only via ground based detectors, but with aircraft systems as well. It proved particularly useful after the Chernobyl accident and was employed by a number of European laboratories. It should prove adaptable to site assessment in the current era of environmental rescue. (author)

  4. 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)

  5. 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)

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

    International Nuclear Information System (INIS)

    Gasser, Estelle

    2014-01-01

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

  7. Application of the Monte Carlo code DETEFF to efficiency calibrations for in situ gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Carrazana González, J.; Cornejo Díaz, N.; Jurado Vargas, M.

    2012-01-01

    We studied the applicability of the Monte Carlo code DETEFF for the efficiency calibration of detectors for in situ gamma-ray spectrometry determinations of ground deposition activity levels. For this purpose, the code DETEFF was applied to a study case, and the calculated 137 Cs activity deposition levels at four sites were compared with published values obtained both by soil sampling and by in situ measurements. The 137 Cs ground deposition levels obtained with DETEFF were found to be equivalent to the results of the study case within the uncertainties involved. The code DETEFF could thus be used for the efficiency calibration of in situ gamma-ray spectrometry for the determination of ground deposition activity using the uniform slab model. It has the advantage of requiring far less simulation time than general Monte Carlo codes adapted for efficiency computation, which is essential for in situ gamma-ray spectrometry where the measurement configuration yields low detection efficiency. - Highlights: ► Application of the code DETEFF to in situ gamma-ray spectrometry. ► 137 Cs ground deposition levels evaluated assuming a uniform slab model. ► Code DETEFF allows a rapid efficiency calibration.

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

    International Nuclear Information System (INIS)

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

    1996-06-01

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

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

    Science.gov (United States)

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

    1997-10-01

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

  10. 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)

  11. 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

  12. Air kerma rate estimation by means of in-situ gamma spectrometry: A Bayesian approach

    International Nuclear Information System (INIS)

    Cabal, Gonzalo; Kluson, Jaroslav

    2008-01-01

    Full text: Bayesian inference is used to determine the Air Kerma Rate based on a set of in situ environmental gamma spectra measurements performed with a NaI(Tl) scintillation detector. A natural advantage of such approach is the possibility to quantify uncertainty not only in the Air Kerma Rate estimation but also for the gamma spectra which is unfolded within the procedure. The measurements were performed using a 3'' x 3'' NaI(Tl) scintillation detector. The response matrices of such detection system were calculated using a Monte Carlo code. For the calculations of the spectra as well as the Air Kerma Rate the WinBugs program was used. WinBugs is a dedicated software for Bayesian inference using Monte Carlo Markov chain methods (MCMC). The results of such calculations are shown and compared with other non-Bayesian approachs such as the Scofield-Gold iterative method and the Maximum Entropy Method

  13. In-situ-gamma ray spectrometry for measurements of environmental radioactivity

    International Nuclear Information System (INIS)

    Winkelmann, I.

    1994-01-01

    A detailed description of the method is presented. The range of application is shown. The calibration of the in-situ gamma ray spectrometer with a HPGe semiconductor detector and the evaluation of the spectra are described. A measuring time of about 15-30 min is sufficient to determine the specific natural and man-made radioactivity of the soil of some ten Bq/m 2 . The results of soil contamination measurements in Germany after the Chernobyl accident are reported. A total of 22 nuclides are detected. The measured contamination for the first days after the accident was as follows: 132 Te/ 132 I - 100 kBq/m 2 , and 131 I - 70 kBq/m 2 . 6 figs., 4 tabs. (orig.)

  14. Radiological Mapping of the Alkaline Intrusive Complex of Jombo, South Coastal Kenya by In-Situ Gamma-Ray Spectrometry

    Science.gov (United States)

    Kaniu, Ian; Darby, Iain G.; Kalambuka Angeyo, Hudson

    2016-04-01

    Carbonatites and alkaline intrusive complexes are rich in a variety of mineral deposits such as rare earth elements (REEs), including Nb, Zr and Mn. These are often associated with U and Th bearing minerals, including monazite, samarskite and pyrochlore. Mining waste resulting from mineral processing activities can be highly radioactive and therefore poses a risk to human health and environment. The Jombo complex located in Kenya's south coastal region is potentially one of the richest sources of Nb and REEs in the world. It consists of the main intrusion at Jombo hill, three associated satellite intrusions at Mrima, Kiruku and Nguluku hills, and several dykes. The complex is highly heterogeneous with regard to its geological formation as it is characterized by alkaline igneous rocks and carbonatites which also influence its radio-ecological dynamics. In-situ gamma spectrometry offers a low-cost, rapid and spatially representative radioactivity estimate across a range of landscapes compared to conventional radiometric techniques. In this work, a wide ranging radiological survey was conducted in the Jombo complex as follow up on previous studies[1,2], to determine radiation exposure levels and source distributions, and perform radiological risk assessments. The in-situ measurements were carried out using a 2.0 l NaI(Tl) PGIS-2 portable detector from Pico Envirotec Inc integrated with GPS, deployed for ground (back-pack) and vehicular gamma-ray spectrometry. Preliminary results of radiological distribution and mapping will be presented. [1] Patel, J. P. (1991). Discovery and Innovation, 3(3): 31-35. [2] Kebwaro, J. M. et. al. (2011). J. Phys. Sci., 6(13): 3105-3110.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-11-15

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

  16. In-situ ground gamma spectrometry — an effective tool for geological mapping (the Male Karpaty Mts., Slovakia)

    Science.gov (United States)

    Mojzeš, Andrej; Porubčanová, Barbara

    2016-06-01

    This contribution presents the results of profile in-situ gamma spectrometry measurements that sought to determine the content of natural radionuclides 40K, 238U and 232Th in a near surface horizon of rocks, their weathering cover and soils in the area of the Malé Karpaty Mts. It is widely established that the exploration of radioactivity of bedrocks and cover rocks can be a very effective and useful tool for both geological mapping, for identifying deposits of mineral resources, and even addressing the issues of structural and tectonic geology. This assertion is equally confirmed by the ground gamma spectrometry measurements carried out as part of this case study on larger scales, seeking more detailed geological structure solutions. The results obtained provide a welcome addition to an already existing database, which monitors the content of naturally occurring radionuclides individually for every rock lithotype of the Western Carpathians, by elaborating on the data collected by previous research and by updating this database for any future needs. The presented results confirmed the low to medium radioactivity levels of rocks and soils in the studied area. The highest values were detected in granitoids and metamorfic phyllitic rocks of the Malé Karpaty Mts. core; the lowest values were detected in carbonates, arenaceous sediments and, above all, amphibolite bodies. In this way, the presented results of the interpreted profile (P5) confirm the model of local geological structure as represented on the most up-to-date edition of the geological map of the Male Karpaty Mts. (Polak et al. 2011).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-10-15

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

  18. Results from the RESUME-95 exercise. In-situ gamma spectrometry performed at Vesivehmaa Airport, Finland

    Energy Technology Data Exchange (ETDEWEB)

    Raeaef, C.L. [Univ. Hospital MAS, Lund Univ., Dept. of Radiation Physics, Malmoe (Sweden)

    1997-12-31

    The Department of Radiation Physics in Malmoe has an agreement with the Swedish Radiation Protection Institute, in which we are obliged to perform instantaneous field measurements of gamma-emitting radionuclides in case of a major release of radionuclides in the environment. The department possesses a High Purity Germanium detector system (35 % commercial at 1.33 MeV) with a PC software spectrum analyser that was purchased and calibrated for this reason. The aim of our participation in the RESUME-95{sup 1} exercise, which took place in Vaeaexsy, Finland, in August 1995, was both to obtain efficiency values for different source geometries (both artificial and natural radionuclides) in field and to compare our results with those of other groups. Furthermore, this exercise was an ideal opportunity to test the full equipment under field conditions. (au).

  19. Measurement of uranium concentrations in situ by gamma-ray spectrometry: an assessment

    International Nuclear Information System (INIS)

    Sheppard, M.I.; Barnard, J.W.; Thibault, D.H.

    1986-01-01

    Portable instruments have often been used to measure radioisotopic concentrations in their natural environment. These units offer the advantages of speed and lower cost, but their accuracy has been questioned, particularly in soil and rock that is naturally stratified and heterogeneous. In our study, low concentrations of uranium in rock and soil were determined in situ by a portable γ-ray spectrometer (GSPEC), and compared with the concentrations determined for samples of rock and soil collected and analyzed by neutron-activation delayed-neutron counting (DNC). The study shows that the portable γ-ray spectrometer must be used with caution when uranium concentrations in soils are needed. For both organic and mineral soils, careful attention to soil stratification is important. Because peat soil does not shield γ-rays as effectively as mineral soil, the GSPEC will detect γ emitters that lie deeper in peat soil. Hence the effect of a layer of high concentration influences the result differently in the two types of soil. If substrate concentrations in the top 15 cm of soil are required for calculating the traditional concentration ratio (CR) values used in environmental impact assessments, the GSPEC soil-concentration values may be appropriate for mineral soils, but unreliable for organic soils. Accurate concentrations were not obtained for rock. (author)

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

    International Nuclear Information System (INIS)

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

    1995-06-01

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

  1. Portable gamma spectrometry: measuring soil erosion in-situ at four Critical Zone Observatories in P. R. China

    Science.gov (United States)

    Sanderson, N. K.; Green, S. M.; Chen, Z.; Wang, J.; Wang, Y.; Wang, R.; Yu, K.; Tu, C.; Jia, X.; Li, G.; Peng, X.; Quine, T. A.

    2017-12-01

    Detecting patterns of soil erosion, redistribution, and/soil nutrient loss is important for long-term soil conservation and agricultural sustainability. Caesium-137 (137Cs) and other fallout radionuclide inventories have been used over the the last 50 years to track soil erosion, transport and deposition on a catchment scale, and have been shown to be useful for informing models of temporal/spatial soil redistribution. Traditional sampling methods usually involves coring, grinding, sieving, sub-sampling and laboratory analysis using HPGe detectors, all of which can be costly and time consuming. In-situ measurements can provide a mechanism for assessment of 137Cs over larger areas that integrate the spatial variability, and expand turnover of analyses. Here, we assess the applicability of an in-situ approach based on radionuclide principles, and provide a comparison of the two approaches: laboratory vs. in-situ. The UK-China Critical Zone Observatory (CZO) programme provides an ideal research platform to assess the in-situ approach to measuring soil erosion: using a portable gamma spectrometer to determine 137Cs inventories. Four extensive field slope surveys were conducted in the CZO's, which covers four ecosystem types in China: karst, red soil, peri-urban, and loess plateau. In each CZO, 3-6 plots were measured along 2 slope transects, with 3 replicated 1 hour counts of 137Cs in each plot. In addition, 137Cs soil depth and bulk density profiles were also sampled for each plot, and lab-derived inventories calculated using traditional methods for comparison. Accurately and rapidly measuring 137Cs inventories using a portable field detector allows for a greater coverage of sampling locations and the potential for small-scale spatial integration, as well as the ability to re-visit sites over time and continually adapt and improve soil erosion/redistribution models, thus more effectively targeting areas of interest with reduced cost and time constraints.

  2. Assay for uranium and determination of disequilibrium by means of in situ high resolution gamma-ray spectrometry

    Science.gov (United States)

    Tanner, Allan B.; Moxham, Robert M.; Senftle, F.E.

    1977-01-01

    Two sealed sondes, using germanium gamma-ray detectors cooled by melting propane, have been field tested to depths of 79 m in water-filled boreholes at the Pawnee Uranium Mine in Bee Co., Texas. When, used as total-count devices, the sondes are comparable in logging speed and counting rate with conventional scintillation detectors for locating zones of high radioactivity. When used with a multichannel analyzer, the sondes are detectors with such high resolution that individual lines from the complex spectra of the uranium and thorium series can be distinguished. Gamma rays from each group of the uranium series can be measured in ore zones permitting determination of the state of equilibrium at each measurement point. Series of 10-minute spectra taken at 0.3- to 0.5-m intervals in several holes showed zones where maxima from the uranium group and from the 222Rn group were displaced relative to each other. Apparent excesses of 230Th at some locations suggest that uranium-group concentrations at those locations were severalfold greater some tens of kiloyears, ago. At the current state of development a 10-minute count yields a sensitivity of about 80 ppm U308. Data reduction could in practice be accomplished in about 5 minutes. The result is practically unaffected by disequilibrium or radon contamination. In comparison with core assay, high-resolution spectrometry samples a larger volume; avoids problems due to incomplete core recovery, loss of friable material to drilling fluids, and errors in depth and marking; and permits use of less expensive drilling methods. Because gamma rays from the radionuclides are accumulated simultaneously, it also avoids the problems inherent in trying to correlate logs made in separate runs with different equipment. Continuous-motion delayed-gamma activation by a 163-?g 252Cf neutron source attached to the sonde yielded poor sensitivity. A better neutron-activation method, in which the sonde is moved in steps so as to place the detector

  3. A new method for the determination of radionuclide distribution in the soil by in situ gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Zombori, P.; Andrasi, A.; Nemeth, I.

    1995-01-01

    In case of major nuclear accidents when larger amount of radioactive material is released into the atmosphere vast areas can become contaminated by the nuclear fallout. The deposited radioactivity penetrates the soil in a complex manner: dry and wet deposition lead to different initial distribution patterns which are further modified by the later transport processes in the upper layers of the soil. The distribution is influenced by various factors (physico-chemical characteristics of the radioisotopes, soil type, weather conditions, environment etc.), the resulting soil profile is hardly predictable. An important lesson we learned from the Chernobyl reactor accident is the great variability of the contamination both in the extent of the deposition and in the penetration features. In recent years - following the reactor accident in Chernobyl - an increased interest for rapid methods of monitoring environmental radioactivity was expressed. The International Atomic Energy Agency initiated a research project to co-ordinate the activities carried out in various laboratories aiming at the development of rapid monitoring procedures. The Co-ordinated Research Project (CRP) G6 10 01 under the title Rapid Instrumental and Separation Methods for Monitoring Radionuclides in Food and the Environment has given a frame for 11 research programs. The Health Physics Department of the KFKI Institute for Atomic Energy Research (the former Central Research Institute for Physics) has taken a part in this CRP with a project titled: Rapid In Situ Gamma Spectrometric Determination of Fallout Radioactivity in the Environment. The main objective of our study was to find a method to estimate the penetration characteristics of the fallout radioactivity by using only spectral information obtained by the in situ spectrometric measurement thus avoiding the need for a long and tiresome sampling and sample analysis procedure

  4. 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...

  5. 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)

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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...

  11. Urban gamma spectrometry. Report 1

    International Nuclear Information System (INIS)

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

    2009-06-01

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

  12. Urban gamma spectrometry. Report 1

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-06-15

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

  13. 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. ...

  14. 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.)

  15. 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

  16. 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)

  17. Compton suppression gamma ray spectrometry

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  18. 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)

  19. 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

  20. 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)

  1. 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

  2. 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)

  3. In situ secondary ion mass spectrometry analysis

    Energy Technology Data Exchange (ETDEWEB)

    Groenewold, G.S.; Applehans, A.D.; Ingram, J.C.; Delmore, J.E.; Dahl, D.A.

    1993-01-01

    The direct detection of tributyl phosphate (TBP) on rocks using molecular beam surface analysis [MBSA or in situ secondary ion mass spectrometry (SIMS)] is demonstrated. Quantities as low as 250 ng were detected on basalt and sandstone with little or no sample preparation. Detection of TBP on soil has proven to be more problematic and requires further study. Ethylenediaminetetraacetic acid (EDTA) is more difficult to detect because it is very reactive with surfaces of interest. Nevertheless, it is possible to detect EDTA if the acidity of the surface is controlled. The detection of EDTA-metal complexes is currently an open question, but evidence is presented for the detection of ions arising from a EDTA-lead complex. Carboxylic acids (i.e., citric, ascorbic, malic, succinic, malonic, and oxalic) give characteristic SIM spectra, but their detection on sample surfaces awaits evaluation.

  4. 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

  5. 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

  6. 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)

  7. 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)

  8. In situ evaluation of radwaste gamma activities

    International Nuclear Information System (INIS)

    Dulama, Cristian; Toma, Al.; Dobrin, R.; Pavelescu, Margarit

    2003-01-01

    There are certain limitations concerning the usage of standard source method for efficiency calibration of gamma-ray spectrometers measuring in extended geometry conditions. These limitations arise from the great diversity of forms and sizes of the objects which are to be measured during decommissioning and radioactive waste management activities. The INR - Pitesti operates a radioactive waste management facilities for both its own necessities and for providing external services. This facility is able to perform conditioning of liquid and solid wastes for interim storage disposal. During the conditioning operations there are certain stages when the radioactive measurement of the storage drums is demanded. We developed a gamma ray spectrometry equipment using a portable MCA Canberra INSPECTOR, a HPGe detector and an INR manufactured collimator. We are using a semiempirical method to calibrate the gamma ray spectrometer for such measurements. A program was written in Visual Basic language and includes a graphical interface for parameters input and data output. The input parameters are stored in text files, which can be loaded, modified or saved on disk as desired. The program was tested to establish the stability of MC simulation and the sensitivity to the input parameters. During the programming process it was possible to verify some code sequences and the results obtained showed that the model used was appropriate. To find out the optimal number of MC histories, which have to be modelled to obtain results of sufficient accuracy, the program was repeatedly run by changing only the number of histories. The relative deviation to the mean of the effective solid angle was calculated. The density of the source material as well as its composition can be changed by input. For comparison the efficiency calibration curves for sources materials having the same elemental composition but different densities ranging from 10 to 1000 kg/m 3 are drawn. The activities of the

  9. 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.

  10. Metrological characterization of the numerical system Adonis for gamma spectrometry

    International Nuclear Information System (INIS)

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

    2005-01-01

    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)

  11. In-situ spectrometry of 137Cs in the soil by unfolding method

    International Nuclear Information System (INIS)

    Fueloep, M.; Ragan, P.; Krnac, S.

    1995-01-01

    This contribution is aimed to the possibility of improving the in-situ gamma spectrometry to be independent on a knowledge about a depth distribution of 137 Cs in soil and sufficiently sensitive for the measurement of the post-Chernobyl 137 Cs at present, as well. The depth distribution of 137 Cs averaged over a large area of soil is obtained by unfolding of the detector responses to primary and in soil forward scattered photons. The proposed method employs detector with and without collimator. The 137 Cs distributions obtained in-situ measurements are analysed, and comparisons are made to the results obtained with soil sampling and with standard in-situ spectrometry, as well. 5 figs., 1 tab., 4 refs

  12. 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...

  13. 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)

  14. 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)

  15. 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

  16. 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)

  17. 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.)

  18. 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

  19. 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)

  20. 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)

  1. 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)

  2. 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)

  3. In situ gamma radiation measurements in the Neoproterozoic rocks ...

    Indian Academy of Sciences (India)

    Keywords. Gamma ray spectrometry; Neoproterozoic; uranium; Sirohi; Sindreth; NW India. ... variable in their signatures reflecting their variable source rocks. In the area between the Balda and Paladi villages, northeast of Sirohi, measurements in vicinity of a N–S running shear zone, have shown U enrichment up to 8 ppm.

  4. Application of PERALS™ alpha spectrometry and gamma spectrometry for analysis and investigation of environmental spills at ISL uranium mining projects.

    Science.gov (United States)

    Borysenko, A; Ostrowski, A; Bellifemine, D; Palmer, G; Haigh, P; Johnston, A

    2014-03-01

    Radiation protection and environmental monitoring in mining requires effective and reliable radionuclide analysis at all stages of the mine project-prior to mining, during operation and through to remediation and decommissioning. The approach presented in this paper was specially developed for the monitoring of radioactive waste resulting from spills during mining and mineral processing operations and uses a combination of high resolution gamma spectrometry, and PERALS™ alpha spectrometry to identify and reliably quantify the activity of the major members of the U-238 decay chain at activities down to 10 mBq g(-1) by direct radionuclide counting and by assessment of the activity of their decay products. This approach has reduced sample preparation and analysis time while providing effective analysis and quantification of naturally occurring radionuclides in environmental samples. It has been successfully applied to several in situ leach (ISL) mining-related projects involving investigations of process material spill impacts and also to routine environmental monitoring.

  5. The software quality control for gamma spectrometry

    International Nuclear Information System (INIS)

    Monte, L.

    1986-01-01

    One of major problems with wich the quality control program of an environmental measurements laboratory is confronted is the evaluation of the performances of software packages for the analysis of gamma-ray spectra. A program of tests for evaluating the performances of the software package (SPECTRAN-F, Canberra Inc.) used by our laboratory is being carried out. In this first paper the results of a preliminary study concerning the evaluation of the performance of the doublet analysis routine are presented

  6. 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

  7. 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)

  8. 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

  9. 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

  10. Program for measuring plutonium quantities by gamma spectrometry: code 'PUMA'

    International Nuclear Information System (INIS)

    Morel, J.; Vallee, M.; Etcheverry, M.

    1989-01-01

    The interest of the gamma spectrometry method for measuring plutonium quantities has been recently demonstrated. A practical outcome of this study is the code 'PUMA' (PlUtonium MAss). This code, characterized by an easy utilisation, is operational on a micro-computer. It can be used for the hold-up measurements, monitoring of wastes and surveillance of facility dismantling. The general structure, subroutine algorithms, the principles used for calculating parameters and corrections are explained [fr

  11. Spatial distribution of gamma radiation levels in Yelagiri Hills, Tamilnadu, India by gamma ray spectrometry

    International Nuclear Information System (INIS)

    Chandrasekaran, A.; Ravishankar, R.; Govardhanan, B.; Vijayagopal, P.; Bramha, S.N.; Venkatraman, B.

    2014-01-01

    The concentration of natural radionuclides in surface soil samples around Yelagiri Hills were determined by gamma ray spectrometry using NaI(Tl) detector. The spatial distribution of uranium and thorium was investigated in soils from the cultivated and undisturbed areas in Yelagiri Hills, Tamilnadu, India. The average absorbed dose rate in the study area was estimated to be 88.62 nGyh -1 . To establish the level of radioactivity at different areas isodose map is drawn between the different sampling locations of Yelagiri hills and the absorbed gamma dose rate. (author)

  12. 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.

  13. 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

  14. 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

  15. 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)

  16. 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)

  17. Rapid in situ gamma spectrometric determination of fallout radioactivity in the environment. Progress report

    International Nuclear Information System (INIS)

    Zombori, Peter

    1995-01-01

    The main aim of the present CRP is to identify the existing analytical methods and develop new ones, if possible, which provide rapid, reliable, and detailed information on the radioactive contamination of the environment after a major nuclear accident. Gamma spectrometry has long been regarded as one of the most applicable radioanalytical techniques but its use for environmental studies requires some further considerations. There are two possible approaches to measure environmental radioactivity: (a) taking samples of the different environmental media and measuring them in a laboratory or (b) taking the spectrometer to the place of interest and making in situ measurements. In the former case sampling is a crucial factor hindering the rapid analysis while the latter case is not always reliable due to the problems and uncertainties of the measurement interpretation. The application of in situ gamma spectrometry for the determination of environmental radioactivity has become increasingly attractive since the advent of the high resolution semiconductor gamma detectors, especially, more recently, portable high purity Ge diodes (HpGe). The applicability of this technique was very well proved after the Chernobyl reactor accident when in situ spectrometry played an important role in the rapid evaluation of the fall-out situation. Our measurements provided information on the amount and composition of the radioactive contamination of the ground surface already in the first hours. These measurements enabled us to predict the time variation of the environmental radioactivity after the stabilization of the situation. The portability of the system was an important factor in performing a rapid and efficient survey in different parts of the country. A serious disadvantage of this method is, however, that it requires some knowledge about the radionuclide distribution in the soil, which is normally determined by tedious and time consuming sample analysis of the different soil

  18. 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)

  19. 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)

  20. 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

  1. 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

  2. In Situ Analytical Characterization of Contaminated Sites Using Nuclear Spectrometry Techniques. Review of Methodologies and Measurements

    International Nuclear Information System (INIS)

    2017-01-01

    Past and current human activities can result in the contamination of sites by radionuclides and heavy metals. The sources of contamination are various. The most important sources for radionuclide release include global fallout from nuclear testing, nuclear and radiological accidents, waste production from nuclear facilities, and activities involving naturally occurring radioactive material (NORM). Contamination of the environment by heavy metals mainly originates from industrial applications and mineralogical background concentration. Contamination of sites by radionuclides and heavy metals can present a risk to people and the environment. Therefore, the estimation of the contamination level and the identification of the source constitute important information for the national authorities with the responsibility to protect people and the environment from adverse health effects. In situ analytical techniques based on nuclear spectrometry are important tools for the characterization of contaminated sites. Much progress has been made in the design and implementation of portable systems for efficient and effective monitoring of radioactivity and heavy metals in the environment directly on-site. Accordingly, the IAEA organized a Technical Meeting to review the current status and trends of various applications of in situ nuclear spectrometry techniques for analytical characterization of contaminated sites and to support Member States in their national environmental monitoring programmes applying portable instrumentation. This publication represents a comprehensive review of the in situ gamma ray spectrometry and field portable X ray fluorescence analysis techniques for the characterization of contaminated sites. It includes papers on the use of these techniques, which provide useful background information for conducting similar studies, in the following Member States: Argentina, Australia, Brazil, Czech Republic, Egypt, France, Greece, Hungary, Italy, Lithuania

  3. 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)

  4. 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)

  5. 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)

  6. 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)

  7. 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

  8. 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.

  9. 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)

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

    International Nuclear Information System (INIS)

    Lindstrom, R.M.

    1993-01-01

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

  11. Determination of the measurement threshold in gamma-ray spectrometry.

    Science.gov (United States)

    Korun, M; Vodenik, B; Zorko, B

    2017-03-01

    In gamma-ray spectrometry the measurement threshold describes the lover boundary of the interval of peak areas originating in the response of the spectrometer to gamma-rays from the sample measured. In this sense it presents a generalization of the net indication corresponding to the decision threshold, which is the measurement threshold at the quantity value zero for a predetermined probability for making errors of the first kind. Measurement thresholds were determined for peaks appearing in the spectra of radon daughters 214 Pb and 214 Bi by measuring the spectrum 35 times under repeatable conditions. For the calculation of the measurement threshold the probability for detection of the peaks and the mean relative uncertainty of the peak area were used. The relative measurement thresholds, the ratios between the measurement threshold and the mean peak area uncertainty, were determined for 54 peaks where the probability for detection varied between some percent and about 95% and the relative peak area uncertainty between 30% and 80%. The relative measurement thresholds vary considerably from peak to peak, although the nominal value of the sensitivity parameter defining the sensitivity for locating peaks was equal for all peaks. At the value of the sensitivity parameter used, the peak analysis does not locate peaks corresponding to the decision threshold with the probability in excess of 50%. This implies that peaks in the spectrum may not be located, although the true value of the measurand exceeds the decision threshold. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. 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)

  13. In situ secondary ion mass spectrometry analysis. 1992 Summary report

    Energy Technology Data Exchange (ETDEWEB)

    Groenewold, G.S.; Applehans, A.D.; Ingram, J.C.; Delmore, J.E.; Dahl, D.A.

    1993-01-01

    The direct detection of tributyl phosphate (TBP) on rocks using molecular beam surface analysis [MBSA or in situ secondary ion mass spectrometry (SIMS)] is demonstrated. Quantities as low as 250 ng were detected on basalt and sandstone with little or no sample preparation. Detection of TBP on soil has proven to be more problematic and requires further study. Ethylenediaminetetraacetic acid (EDTA) is more difficult to detect because it is very reactive with surfaces of interest. Nevertheless, it is possible to detect EDTA if the acidity of the surface is controlled. The detection of EDTA-metal complexes is currently an open question, but evidence is presented for the detection of ions arising from a EDTA-lead complex. Carboxylic acids (i.e., citric, ascorbic, malic, succinic, malonic, and oxalic) give characteristic SIM spectra, but their detection on sample surfaces awaits evaluation.

  14. 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)

  15. Gamma ray spectrometry results from core samples collected for RESUME 95

    International Nuclear Information System (INIS)

    Sanderson, D.C.W.; Allyson, J.D.; Toivonen, H.; Honkamaa, T.

    1997-01-01

    Field sampling of an airfield at Vesivehmaa, near Vaeaeksy, Finland (Area I) was carried out between 26-29 May 1995, to establish the radionuclide deposition and inventory of Chernobyl derived 137 Cs, and natural radionuclides. The objective was to establish a common calibration site for in-situ and airborne gamma spectrometers, for Exercise RESUME 95 conducted in August 1995. The report presents the sampling details, handling and treatment. The analyses are discussed with particular emphasis given to 137 Ca, 134 Cs, 40 K, 214 Bi and 208 radionuclides, and the quantification of their respective deposition and inventories. The results have been used to estimate the effective concentrations of nuclides at the calibration site for in-situ and airborne gamma spectrometry, and the depth distribution. For 137 Cs the weighted mean activity per unit area takes on values of 50.7±5.2 kBq m -2 at 1 m ground clearance, 51.1±6.9 kBq m -2 at 50 m height and 47.9±8.5 kBq m -2 at 100 m. The similarity of these values confirms the suitability of the Vesivehmaa site for comparison of in-situ and airborne results despite variations of a factor of two between results from individual cores. The mean α/ρ value for 137 Cs in Area I is 0.77±0.10 cm 2 g -1 (relaxation mass per unit area, β 1.31±0.15 gcm -2 ). Additional soil sampling across parts of Area II (a 6x3 km area selected for mapping Chernobyl deposition) was carried out. The mean level of 137 Cs activity from these samples was 92.4±63 kBq m -2 , a sample taken near Laihansuo showing the largest value obtained at 172 kBq m -2 . (EG)

  16. 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

  17. 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)

  18. Study on the natural radioactivity from the region of Presidente Figueiredo (AM), Brazil, using gamma spectrometry

    International Nuclear Information System (INIS)

    Da Silva, Jose Ribamar Silveira

    1999-01-01

    A gamma spectrometry profile was carried out along BR174 highway, that crosses some lithostratigraphic units of the North portion of the Sedimentary Basin of Amazon. Measurements in situ were realized in 116 points, 1 km apart, using a GAD-6 gamma-spectrometer and samples of rocks and soils were collected in geologically representative points, for gamma measurements using a shielded detector of NaI(Tl) available in the Nuclear Geophysics Laboratory of IAG/USP. The criterion used for evaluating the reliability degree of the concentration values of eU (ppm), eTh (ppm) and %K was to establish mathematically detection limits, for all measurement points. Every these points had been located using GPS with accuracy of 50 m to become possible a future detailed study. The purpose of matching portable gamma spectrometer and laboratory determinations was to compare the 2 techniques, using the criterion of detectability limits, and to verify the influence of 222 Rn atmospheric radioactive gas in field measurements. In the case of portable detector, it allows fast measurements and the sensor 'sees' a big volume of material (rock, soil...), that makes it more representative. In some situations where atmospheric phenomena of thermal inversion occurs, measurement can be affected by the 222 Rn cosmic background. Presence of radon daughter elements, associated with aerosols, in this tropical environment (high values of temperature and humidity), where the speed of the wind that could exhaust this gas is practically zero. It is observed that the values of concentration in the some points, got with these 2 techniques, have the same trend, and the stretches where peaks of concentration of K also occur and U and Th are associated with the presence of granite out corps, great boulders, and clay soils from weathering of these rocks. (author)

  19. Ex-situ and in-situ observations of the effects of gamma radiation on lithium ion battery performance

    Science.gov (United States)

    Tan, Chuting; Bashian, Nicholas H.; Hemmelgarn, Chase W.; Thio, Wesley J.; Lyons, Daniel J.; Zheng, Yuan F.; Cao, Lei R.; Co, Anne C.

    2017-07-01

    Radiation effects induced by gamma rays on battery performance were investigated by measuring the capacity and resistance of a series of battery coin cells in-situ directly under gamma radiation and ex-situ. An experimental setup was developed to charge and discharge batteries directly under gamma radiation, equipped with precise temperature control, at The Ohio State University Nuclear Reactor Lab. Latent effects induced by gamma radiation on battery components directly influence their performance. Charge and discharge capacity and overall resistance throughout a time span of several weeks post irradiation were monitored and compared to control groups. It was found that exposure to gamma radiation does not significantly alter the available capacity and the overall cell resistance immediately, however, battery performance significantly decreases with time post irradiation. Also, batteries exposed to a higher cumulative dose showed close-to-zero capacity at two-week post irradiation.

  20. 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.

  1. A simple gamma spectrometry method for evaluating the burnup of MTR-type HEU fuel elements

    Science.gov (United States)

    Makmal, T.; Aviv, O.; Gilad, E.

    2016-10-01

    A simple method for the evaluation of the burnup of a materials testing reactor (MTR) fuel element by gamma spectrometry is presented. The method was applied to a highly enriched uranium MTR nuclear fuel element that was irradiated in a 5 MW pool-type research reactor for a total period of 34 years. The experimental approach is based on in-situ measurements of the MTR fuel element in the reactor pool by a portable high-purity germanium detector located in a gamma cell. To corroborate the method, analytical calculations (based on the irradiation history of the fuel element) and computer simulations using a dedicated fuel cycle burnup code ORIGEN2 were performed. The burnup of the MTR fuel element was found to be 52.4±8.8%, which is in good agreement with the analytical calculations and the computer simulations. The method presented here is suitable for research reactors with either a regular or an irregular irradiation regime and for reactors with limited infrastructure and/or resources. In addition, its simplicity and the enhanced safety it confers may render this method suitable for IAEA inspectors in fuel element burnup assessments during on-site inspections.

  2. 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

  3. Neutron activation analysis of lipsticks using gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Mirsa, G.; Mittal, V.K.

    2004-01-01

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

  4. 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...

  5. Fission products control by gamma spectrometry in purex process solutions

    International Nuclear Information System (INIS)

    Goncalves, Maria Augusta

    1982-01-01

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

  6. Fisson product control by gamma spectrometry in Purex process solutions

    International Nuclear Information System (INIS)

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

    1982-01-01

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

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

    International Nuclear Information System (INIS)

    Chesselet, R.

    1969-01-01

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

  8. Technology information profile: RL321103 -- In situ gamma spectrometer

    International Nuclear Information System (INIS)

    Schilk, A.J.

    1993-11-01

    Past operations of uranium production and support facilities at several Department of Energy (DOE) sites have occasionally resulted in the local contamination of some surface and subsurface soils. Such contamination commonly occurs within waste burial sites, cribs, pond bottom sediments, and areas surrounding waste tanks or uranium scrap, ore, tailing, and slag heaps. The thorough cleanup of these sites is a major public concern and a high priority for the DOE, but before any effective remedial protocols can be established, the three-dimensional distributions of the uranium contaminants must be adequately characterized. Unfortunately, traditional means of obtaining soil activities (e.g., grab sampling followed by laboratory analyses) are notoriously cumbersome, expensive, time-consuming, and often non-representative when very large areas are being surveyed. Hence, new technologies must be developed, or existing ones improved, to allow for the cheaper, better, faster (i.e., real-time) and safer characterization of uranium concentrations at these critical sites. The primary objective for this program is to develop, construct, and field/pilot test the in situ gamma spectrometer for the rapid measurement of uranium in surface and shallow subsurface soils at the Fernald site in Ohio

  9. 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.)

  10. 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 ...

  11. Determining Some Parameters Of Uranium Material By GAMMA Spectrometry Using Intrinsic Efficiency Calibration

    International Nuclear Information System (INIS)

    Le Tuan Anh; Bui Minh Hue; Bui Van Loat; Nguyen Cong Tam

    2011-01-01

    Abundance and age of uranium material are two significant parameters. Traditionally, they are determined by alpha spectrometry and mass-spectrometry, which are destructive methods. In this report, we exhibit the result of abundance and age, which were determined by gamma-spectrometry using intrinsic efficiency calibration. This is a nondestructive method without using standard source or any reference samples, and applicable to material of any geometrical shape. The result obtained is in good agreement with the results obtained by other authors. (author)

  12. Dose response of alanine and methyl alanine towards gamma and in-situ alpha irradiation

    International Nuclear Information System (INIS)

    Mohapatra, M.; Rajeswari, B.; Bhide, M.K.; Rane, Vinayak; Kadam, R.M.

    2017-01-01

    In situ alpha and external gamma dose response of two ESR (electron spin resonance) dosimetric materials namely alanine and methyl alanine were investigated. It was observed that alanine dosimeter had a better dose response in comparison to methyl alanine for the in-situ alpha irradiation by using 239 Pu powder. On the other hand, in case of gamma radiation, methyl alanine was found to have the sensitivity as twice that of alanine. (author)

  13. Gamma ray spectrometry results from core samples collected for RESUME 95

    Energy Technology Data Exchange (ETDEWEB)

    Sanderson, D.C.W.; Allyson, J.D. [SURRC, East Kilbride, Scotland (United Kingdom); Toivonen, H.; Honkamaa, T. [STUK, Helsinki (Finland)

    1997-12-31

    Field sampling of an airfield at Vesivehmaa, near Vaeaeksy, Finland (Area I) was carried out between 26-29 May 1995, to establish the radionuclide deposition and inventory of Chernobyl derived {sup 137}Cs, and natural radionuclides. The objective was to establish a common calibration site for in-situ and airborne gamma spectrometers, for Exercise RESUME 95 conducted in August 1995. The report presents the sampling details, handling and treatment. The analyses are discussed with particular emphasis given to {sup 137}Ca, {sup 134}Cs, {sup 40}K, {sup 214}Bi and {sup 208} radionuclides, and the quantification of their respective deposition and inventories. The results have been used to estimate the effective concentrations of nuclides at the calibration site for in-situ and airborne gamma spectrometry, and the depth distribution. For {sup 137}Cs the weighted mean activity per unit area takes on values of 50.7{+-}5.2 kBq m{sup -2} at 1 m ground clearance, 51.1{+-}6.9 kBq m{sup -2} at 50 m height and 47.9{+-}8.5 kBq m{sup -2} at 100 m. The similarity of these values confirms the suitability of the Vesivehmaa site for comparison of in-situ and airborne results despite variations of a factor of two between results from individual cores. The mean {alpha}/{rho} value for {sup 137}Cs in Area I is 0.77{+-}0.10 cm{sup 2}g{sup -1} (relaxation mass per unit area, {beta} 1.31{+-}0.15 gcm{sup -2}). Additional soil sampling across parts of Area II (a 6x3 km area selected for mapping Chernobyl deposition) was carried out. The mean level of {sup 137}Cs activity from these samples was 92.4{+-}63 kBq m{sup -2}, a sample taken near Laihansuo showing the largest value obtained at 172 kBq m{sup -2}. (EG). 17 refs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  15. Gamma spectrometry inspection of TRIGA MARK II fuel using caesium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Karimzadeh, S., E-mail: sam.karimzadeh@ati.ac.a [Vienna University of Technology, Institute of Atomic and Subatomic Physics (ATI), Stadionallee 2, A-1020 Vienna (Austria); Khan, R.; Boeck, H. [Vienna University of Technology, Institute of Atomic and Subatomic Physics (ATI), Stadionallee 2, A-1020 Vienna (Austria)

    2011-01-15

    Research highlights: Cs isotopes are the best choices for the burn up determination of spent fuel. Gamma spectrometer calibration using MCNP5. Cs-ratio can be applied by relative calibration method. - Abstract: Gamma spectrometry is one of the common methods to inspect the spent fuel from research reactors. This method has been applied to in-pool measurements of the Spent Fuel Elements (SPEs) of the TRIGA Mark II research reactor. Due to mixed nature of the reactor core and complicated irradiation history of the fuel elements (FEs), the gamma spectrometry of the FE establishes improvements in the calculation and measurement of the SPE. In order to inspect the TRIGA SPE from dry storage and cooled fuel from the reactor pool, the selected spend fuels are scanned and measured using the fuel-scanning machine. Gamma spectrometry is performed by HPGe detector for spend fuel inspection and determination of the {sup 137}Cs activity and {sup 134}Cs/{sup 137}Cs ratio. In this work, the steps of the detector calibration and the use of the Monte Carlo radiation transport code (MCNP5) have been described. In addition, the fuel-scanning machine and the gamma spectrometer are modelled by MCNP5 to simulate the gamma transport from fuel to detector. It also simulate the gamma spectrometer calibration for the burn up determination of the spend fuel. The results from MCNP5 simulation are applied to spectroscopic measurements and compared with the theoretical predictions of the neutronics code ORIGEN2 in this research work.

  16. 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

  17. A simple method for the absolute determination of uranium enrichment by high-resolution {gamma} spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Korob, R.O. [Unidad de Actividad Radioquimica y Quimica de las Radiaciones, Comision Nacional de Energia Atomica, Centro Atomico Ezeiza, Presbitero Juan Gonzalez y Aragon No. 15 Partido de Ezeiza, Provincia de Buenos Aires (Argentina)]. E-mail: korob@cae.cnea.gov.ar; Blasiyh Nuno, G.A. [Unidad de Actividad Gestion de Residuos Radiactivos, Comision Nacional de Energia Atomica, Centro Atomico Ezeiza, Presbitero Juan Gonzalez y Aragon No. 15 Partido de Ezeiza, Provincia de Buenos Aires (Argentina)

    2006-05-15

    A simple method for the determination of uranium enrichment using high-resolution {gamma} spectrometry is presented in this paper. The method relies solely on the {gamma}-ray emission probabilities of {sup 235}U and {sup 234m}Pa, and an iterative procedure for the least squares fit of a polynomial to a set of experimentally determined data. To ensure the reliability of the {sup 234m}Pa {gamma}-ray emission probabilities employed, a new determination of these probabilities was carried out using a combination of {gamma} spectrometry and Cerenkov counting of a purified {sup 234}Th solution. Using these new data, a maximum difference of {approx}5% has been found between the experimental and declared uranium enrichment in a set of solid and liquid samples containing uranium compounds.

  18. Airborne gamma spectrometry - towards integration of European operational capability

    International Nuclear Information System (INIS)

    Toivonen, H.

    2003-01-01

    Full text: A nuclear threat can take several forms. The fallout from nuclear weapons or from an accident in a nuclear power reactor may contaminate a large area (>>100,000 km 2 ) whereas the dispersion of single sources, either accidentally or deliberately (dirty bomb), contaminates a much smaller area, perhaps only a few thousand square kilometres or less. Airborne gamma spectrometry (AGS) plays an important role in providing detailed information an the dispersion of radioactive materials. AGS using a fixed-wing or a rotary-wing aircraft is at its best in fallout mapping and in searching for orphan sources. Plume tracking could be a third application but is very complex, and there is a risk of vehicle contamination, which would deteriorate mission capability in the later phases of an accident. Because of obvious advantages, unmanned aerial vehicles could be used to monitor the release rate at the site of an accident and perhaps the plume itself. The aim of the present paper is to discuss ways to utilize existing European airborne monitoring capabilities for multilateral assistance in an accident and to give some thoughts to how an integrated system could be developed to take into account various national measuring strategies. In a large-scale accident, it is to be expected that the European countries use their radiological resources to map their own territory. It is realistic to think of assistance by transferring equipment and staff to another country only in accident scenarios where a country or countries with essential AGS capability would not have been affected by the fallout. Various AGS survey results can be fused only if a common platform for data exchange is available. Formats and protocols have been developed for special cases (ECCOMAGS, Nuclear Fission Safety, 4 th and 5 th Framework Programmes) but there are no universal solutions applicable to different situations and Instruments. The hardware and software among the European AGS teams are tailor

  19. 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.

  20. An optimum analysis sequence for environmental gamma-ray spectrometry

    International Nuclear Information System (INIS)

    De la Torre, F.; Rios M, C.; Ruvalcaba A, M. G.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L.

    2010-10-01

    This work aims to obtain an optimum analysis sequence for environmental gamma-ray spectroscopy by means of Genie 2000 (Canberra). Twenty different analysis sequences were customized using different peak area percentages and different algorithms for: 1) peak finding, and 2) peak area determination, and with or without the use of a library -based on evaluated nuclear data- of common gamma-ray emitters in environmental samples. The use of an optimum analysis sequence with certified nuclear information avoids the problems originated by the significant variations in out-of-date nuclear parameters of commercial software libraries. Interference-free gamma ray energies with absolute emission probabilities greater than 3.75% were included in the customized library. The gamma-ray spectroscopy system (based on a Ge Re-3522 Canberra detector) was calibrated both in energy and shape by means of the IAEA-2002 reference spectra for software intercomparison. To test the performance of the analysis sequences, the IAEA-2002 reference spectrum was used. The z-score and the reduced χ 2 criteria were used to determine the optimum analysis sequence. The results show an appreciable variation in the peak area determinations and their corresponding uncertainties. Particularly, the combination of second derivative peak locate with simple peak area integration algorithms provides the greater accuracy. Lower accuracy comes from the combination of library directed peak locate algorithm and Genie's Gamma-M peak area determination. (Author)

  1. An optimum analysis sequence for environmental gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    De la Torre, F.; Rios M, C.; Ruvalcaba A, M. G.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L., E-mail: fta777@hotmail.co [Universidad Autonoma de Zacatecas, Centro Regional de Estudis Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2010-10-15

    This work aims to obtain an optimum analysis sequence for environmental gamma-ray spectroscopy by means of Genie 2000 (Canberra). Twenty different analysis sequences were customized using different peak area percentages and different algorithms for: 1) peak finding, and 2) peak area determination, and with or without the use of a library -based on evaluated nuclear data- of common gamma-ray emitters in environmental samples. The use of an optimum analysis sequence with certified nuclear information avoids the problems originated by the significant variations in out-of-date nuclear parameters of commercial software libraries. Interference-free gamma ray energies with absolute emission probabilities greater than 3.75% were included in the customized library. The gamma-ray spectroscopy system (based on a Ge Re-3522 Canberra detector) was calibrated both in energy and shape by means of the IAEA-2002 reference spectra for software intercomparison. To test the performance of the analysis sequences, the IAEA-2002 reference spectrum was used. The z-score and the reduced {chi}{sup 2} criteria were used to determine the optimum analysis sequence. The results show an appreciable variation in the peak area determinations and their corresponding uncertainties. Particularly, the combination of second derivative peak locate with simple peak area integration algorithms provides the greater accuracy. Lower accuracy comes from the combination of library directed peak locate algorithm and Genie's Gamma-M peak area determination. (Author)

  2. 134Cs emission probabilities determination by gamma spectrometry

    Science.gov (United States)

    de Almeida, M. C. M.; Poledna, R.; Delgado, J. U.; Silva, R. L.; Araujo, M. T. F.; da Silva, C. J.

    2018-03-01

    The National Laboratory for Ionizing Radiation Metrology (LNMRI/IRD/CNEN) of Rio de Janeiro performed primary and secondary standardization of different radionuclides reaching satisfactory uncertainties. A solution of 134Cs radionuclide was purchased from commercial supplier to emission probabilities determination of some of its energies. 134Cs is a beta gamma emitter with 754 days of half-life. This radionuclide is used as standard in environmental, water and food control. It is also important to germanium detector calibration. The gamma emission probabilities (Pγ) were determined mainly for some energies of the 134Cs by efficiency curve method and the Pγ absolute uncertainties obtained were below 1% (k=1).

  3. Minimum Detectable Activity in gamma spectrometry and its use in low level activity measurements

    International Nuclear Information System (INIS)

    Done, L.; Ioan, M-R.

    2016-01-01

    In this paper there are described three different algorithms of Minimum Detectable Activity (MDA) calculus, and its use in high resolution gamma spectrometry. In the first part, few introductive theoretical aspects related to the MDA are presented. Further, the theory was applied to real gamma rays spectrometry measurements and the results were compared with the activities reference values. Two different gamma spectrometry systems, both of them using High Purity Germanium (HPGe) detectors, but having different efficiencies, were used. Samples having different geometries and radionuclides content were measured. The measured samples were made by dissolving of some acids containing anthropogenic radionuclides in water, obtaining a density of 1 g/cm 3 . Choosing this type of matrix was done because of its high homogeneity. - Highlights: • Three different MDA algorithms were applied to gamma spectrometry measurements. • The measurements were performed using two HPGe detectors. • MDA performances of the two spectrometric systems were compared. • The measured samples had different geometries and contained a mixture of radionuclides. • MDA was studied also as a function of measuring time.

  4. 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...

  5. Fourier transformation methods in the field of gamma spectrometry

    Indian Academy of Sciences (India)

    The basic principles of a new version of Fourier transformation is presented. This new version was applied to solve some main problems such as smoothing, and denoising in gamma spectroscopy. The mathematical procedures were first tested by simulated data and then by actual experimental data.

  6. Intercomparison of alpha and gamma spectrometry techniques used in (210)Pb geochronology.

    Science.gov (United States)

    Zaborska, Agata; Carroll, Jolynn; Papucci, Carlo; Pempkowiak, Janusz

    2007-01-01

    (210)Pb geochronology is a widely used tool in sedimentological studies aimed at the absolute ages of modern sediments (up to 100 years). (210)Pb activities required to model sedimentation regimes are measured using either alpha, gamma or beta spectrometry. Sediment accumulation rates derived from (210)Pb activity profiles measured by these methods are often used interchangeably in mass balance studies. Yet there is a lack of investigations considering the comparability of data derived using different analytical methods. Differences between methods could be caused by different behaviors of (210)Pb and (210)Po (used for alpha measurement) in the marine environment. In gamma spectrometry errors may arise when many gamma emitters are measured simultaneously and their activity peaks overlap. In alpha spectrometry chemical separation of (210)Po may result in analytical error due to incomplete sample dissolution. In the present study we evaluate total, supported and excess (210)Pb activities and their use in deriving sediment accumulation rates and (210)Pb excess inventories for three sediment cores collected from the Barents Sea. (210)Pb activities derived by alpha and gamma methods are shown to agree within counting error and there is also good agreement in the derived sediment accumulation rates. The inherent compatibility of analytical results based on alpha or gamma techniques is established.

  7. The impact of uncertainty in the elemental composition of the certified reference material on gamma spectrometry

    International Nuclear Information System (INIS)

    Maurice Miller; Mitko Voutchkov

    2014-01-01

    In this paper the impact of the uncertainty in the elemental composition of the certified reference material (CRM) used for absolute efficiency calculations in gamma spectrometry is investigated. The method involved the use of semi-empirical modeling using solid angle concepts. The samples involved were a standard Jamaican soil, four bauxite reference samples from NIST and a standard ICRU reference material configuration simulating the calibrating CRM. The results indicate that at gamma energies below 60 keV, the impact on the bauxite reference samples and local soil samples resulted in errors up to 43 and 70 % respectively when the elemental composition of the efficiency calibrating reference sample was ignored. A set of equations for correcting the errors introduced were developed. The modeling of a theoretical soil type validated the process of ashing soils for low energy gamma spectrometry due to the extremely high errors introduced by the element carbon. (author)

  8. 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)

  9. 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

  10. Transcription factor AP-2gamma is a developmentally regulated marker of testicular carcinoma in situ and germ cell tumors

    DEFF Research Database (Denmark)

    Hoei-Hansen, Christina E; Nielsen, John E; Almstrup, Kristian

    2004-01-01

    PURPOSE: Transcription factor activator protein-2gamma (TFAP2C, AP-2gamma) was reported previously in extraembryonic ectoderm and breast carcinomas but not in the testis. In our recent gene expression study we detected AP-2gamma in carcinoma in situ testis (CIS, or intratubular germ cell neoplasia......-2gamma in testicular CIS and in testicular germ cell tumors of young adults and confirmed differential expression of AP-2gamma in somatic tumors. We found that AP-2gamma expression was regulated by retinoic acid in an embryonal carcinoma cell line (NT2). The investigation of ontogeny of AP-2gamma...

  11. Gamma spectrometry on R139-66/5 gamma scan wires 1-5

    International Nuclear Information System (INIS)

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

    1994-08-01

    In this report the results of R139-66/5 are presented. In section 2 a brief description of the gamma scan wires is given. A description of the gamma-scan facility is given ion section 3. The experimental results are given in section 4. (orig./WL)

  12. Borehole Logging for Uranium by Gamma-Ray Spectrometry

    DEFF Research Database (Denmark)

    Løvborg, Leif; Nyegaard, P.; Christiansen, E. M.

    1980-01-01

    The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium-iodide, and the photo......The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium...... of the spectrometer system were determined by calculating the average number of U and thorium (Th) counts per meter of borehole and comparing these with the U-Th concentrations in 1-m sections of analyzed drill core. The sensitivity and the background count rate in the uranium window varied appreciably from one hole...

  13. Organization of a multichannel analyzer for gamma ray spectrometry

    International Nuclear Information System (INIS)

    Robinet, Genevieve

    1988-06-01

    This report describes the software organization of a medium scale multichannel analyzer for qualitative and quantitative measurements of the gamma rays emitted by radioactive samples. The first part reminds basis of radioactivity, principle of gamma ray detection, and data processing used for interpretation of a nuclear spectrum. The second part describes first the general organization of the software and then gives some details on interactivity, multidetector capabilites, and integration of complex algorithms for peak search and nuclide identification;problems encountered during the design phase are mentioned and solutions are given. Basic ideas are presented for further developments, such as expert system which should improve interpretation of the results. This present software has been integrated in a manufactured multichannel analyzer named 'POLYGAM NU416'. [fr

  14. Determination of burnup grade of fuel plates by gamma spectrometry

    International Nuclear Information System (INIS)

    Terremoto, Luis A.A.; Zeituni, Carlos A.; Perrotta, Jose A.

    1999-01-01

    This work describes absolute burnup measurements on spent MTR fuel elements by means of non-destructive gamma-ray spectroscopy which correlates activities of radioactive fission products with the fissioned mass of 235 U. Experiments based on such method were performed at the storage pool area of the IEA-R1 research reactor. The obtained results were compared with calculational ones based on neutronics. (author)

  15. Detection limit of 238U by gamma spectrometry

    International Nuclear Information System (INIS)

    Tartaglione, A.; Blostein, J.; Mayer, R

    2004-01-01

    The detection limit of 238 U was determined by gamma spectra measurements of a depleted uranium sample using four NaI(Tl) scintillators in a compact arrangement.The sample was shielded with 5 and 10 cm of lead.Two different methods for data processing were used and compared.It was established that an appropriate array of 40 detectors could establish the presence of 220 g of this material in only 5 minutes [es

  16. Non destructive and destructive dating by low energy gamma ray spectrometry

    International Nuclear Information System (INIS)

    Brrada, M.; Choukri, A.; El-Khoukhi, T.

    1994-01-01

    Alpha spectrometry is mainly used in U-series dating for the determination of equilibrium ratios, but chemical attacks, radiochemical separations, preparations of thin layers are needed. To avoid this destructive method, gamma spectrometry in the 40-380 KeV region by coaxial Germanium detectors, was also used, but 234-U is still difficult to determine because its 53.2 KeV gamma ray interferes absolutely with the 10 times more intense gamma ray of 214-Pb. In our work we were interested in the 20-80 KeV region of the gamma spectrum obtained by a small Germanium planar detector having an excellent resolution. It contains the 25.6, 27.4, 50.2, 63.3 and 67.7 KeV gamma rays emitted respectively by 231-Th, 231-Pa, 227-Th, (234-U + 214-Pb), 234-Th and 230-Th, which are all the radionuclides needed for dating. The peaks obtained with such a detector are better resolved, with a lower background, because this detector is less sensitive to higher energy and more intense gamma rays coming from 226-Ra decay products, than the voluminous coaxial detector. We worked on a geological sample containing uranium and coming from the Ganntour moroccan phosphate ore. In this paper we present 3 gamma ray spectra, one obtained directly with a Germanium coaxial detector in the 40-380 KeV region, the second obtained directly with a germanium planar detector in the 20-80 KeV region, and the third obtained after chemical separation of radium, with a germanium planar detector in the 20-80 KeV region. Good agreement was found with the results of alpha spectrometry. 2 figs., 1 tab., 2 refs. (author)

  17. Sensitivity of in-situ gamma-ray spectra to soil density and water content

    NARCIS (Netherlands)

    de Groot, A.V.; van der Graaf, E.R.; de Meijer, R.J.; Maucec, M.

    2009-01-01

    The effects of sediment water content and bulk density on measurements of in-situ environmental gamma-radiation were investigated using Monte-Carlo simulations. The simulations consider a large bismuth-germanate detector in a semi-infinite geometry. The volume contributing radiation to the detector

  18. Gamma spectroscopy for fast in-situ measurements

    International Nuclear Information System (INIS)

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

    1990-01-01

    The problem is to determine the dose rate contributions from particular radionuclides deposited in the soil. The authors show how information from the gamma energy spectra for a particular measurement chain can be evaluated. In particular the chain has a portable germanium detector above the ground with a multichannel and an associated IBM-PC. A comparison of doses gained by this method and by soil samplings from different depths and sample preparation is made. (Quittner)

  19. Radioactive characterization of samples in various geometry by gamma ray spectrometry

    International Nuclear Information System (INIS)

    Dulama, Cristian; Dobrin, Relu; Toma, Alexandru

    2001-01-01

    There are certain limitations concerning the usage of standard source method for efficiency calibration of gamma - ray spectrometers measuring in extended geometry. These limitations arise from the great diversity of forms, dimensions and densities of the objects which are to be measured. One of the steps in fuel fabrication cycle is the radioactive waste conditioning. At Institute for Nuclear Research INR a radioactive waste management facility operates both for its own purposes and for providing external services. This facility is able to perform conditioning of liquid and solid wastes for interim storage. During the waste conditioning operations there are certain stages when the radioactive measurement of the storage drums is demanded. In order to be able to establish the radioactive content within storage drums during the various procedures that are performed on them at our waste treatment facility we designed and manufactured a mobile equipment for 'in situ' spectrometry. A portable high purity germanium detector was used together with a compact workstation Canberra INSPECTOR incorporating a multi-channel analyzer, a spectroscopic amplifier and a high voltage power supply. Spectral data are processed on-line with a SubNote IBM 486 compatible PC using GeniePC, an OS/2 based spectroscopy software from Canberra. A compact, modular lead housing for the detector was designed and manufactured at INR, using uncontaminated Pb and an inner layer of copper. In front of the detector a lead collimator with cylindrical hole was used to reduce the range of variation for incidence angle. Hence several collimators were manufactured with 10, 20, 40 and 60 mm diameter holes to be able to ensure a proper counting rate in a large range of drum's specific activities by simply changing the collimator. For the efficiency calibration of the spectrometric chain a computer program was written, based on a Monte Carlo algorithm, using a semiempirical method to determinate the effective

  20. Planetary Geochemistry Techniques: Probing In-Situ with Neutron and Gamma Rays (PING) Instrument

    Science.gov (United States)

    Parsons, A.; Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S.; Lin, L.; McClanahan, T.; Nankung, M.; Nowicki, S.; Schweitzer, J.; hide

    2011-01-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument is a promising planetary science application of the active neutron-gamma ray technology so successfully used in oil field well logging and mineral exploration on Earth. The objective of our technology development program at NASA Goddard Space Flight Center's (NASA/GSFC) Astrochemistry Laboratory is to extend the application of neutron interrogation techniques to landed in situ planetary composition measurements by using a 14 MeV Pulsed Neutron Generator (PNG) combined with neutron and gamma ray detectors, to probe the surface and subsurface of planetary bodies without the need to drill. We are thus working to bring the PING instrument to the point where it can be flown on a variety of surface lander or rover missions to the Moon, Mars, Venus, asteroids, comets and the satellites of the outer planets.

  1. 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)

  2. Designing and developing of data evaluation and analysis software applied to gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Asgharizadeh, F.; Bahrami Samani, A.; Rahighi, J.; Shahidi, F.

    2007-01-01

    This study is intended to design and develop software for gamma spectral data evaluation and analysis suitable for a variety of gamma-ray spectrometry systems. The software is written in Visual C++. It is designed to run under Microsoft Windows Operating System. The software is capable of covering all the necessary steps for spectral data evaluation and analysis of the collected data. These include peak search, energy calibration, gross and net peak area calculation, peak centroid determination and peak width calculation of the derived gamma-ray peaks. The software offers the ability to report qualitative and quantitative results. The analysis includes: Peak position identification (qualitative analysis) and calculating of its characteristics; Net peak area calculation by subtracting background; Radioactivity estimation (quantitative analysis) using comparison method for gamma peaks from any radioisotopes present during counting; Radioactivity estimation (quantitative analysis) after efficiency calibration; Counting uncertainties calculation; Limit of detection (LOD) estimation. (author)

  3. 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

  4. Measurement of radioactive contamination in the foodstuffs by gamma spectrometry

    International Nuclear Information System (INIS)

    Ihsanullah; Jan, F.; Shafiq, M.; Orfi, S.D.; Atta, M.A.

    1997-01-01

    The Chernobyl nuclear reactor accident in 1986, resulted in the increase of radioactive contamination at a global level. To avoid undesirable exposure to public, Pakistan like other countries imposed radioactive contamination levels on food items. Various imported/to be exported and locally purchased food items for human consumption have been analysed for gamma emitting radionuclides. Amongst the food items, special attention was focussed on the imported dry milk. In addition to naturally occurring K-40 radionuclide, small amounts of Cs-137 and Cs-134 fission products have been detected in some of the samples. The concentrations of these two fission radionuclides are presented and compared with the relevant limits. (author)

  5. Determination of Ra-226 by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Martinez Lobo, A.

    1988-01-01

    This work deals with the method of determination of 226 Ra by low energy photon spectrometry. For this purpose, the interference due to 235 U, that emits a photon with a close energy, has to be considered. The contribution of 235 U to the 186 KeV photopeak is studied through the 63 KeV 234 Th and the 144 KeV 235 U emissions. From the minimum detectable activity of 226 Ra it is discussed the applicability of this method to several kind of samples. (Author)

  6. Neutron and Gamma Spectrometry in the Research Reactor LR-0

    Science.gov (United States)

    Zaritskiy, S.; Ošmera, B.; Cvachovec, F.; Mařik, M.; Pošta, S.; Rypar, V.; Riazanov, D.; Lichadeev, V.; Kolros, A.; Matěj, Z.

    2015-06-01

    The complex measurement system for the full-scale VVER models (mock-ups), created in the research reactor LR-0, is discussed. Fast neutron (energy from 0.5 to 10 MeV) and gamma spectra are measured in several representative points of the mock-ups by the two-parameter spectrometer with the cylindrical stilbene scintillation detectors. Measurements in the thermal and epithermal neutron region are carried out with the activation method using a broad set of activation monitors and with the 3He(n,p) counter. Activation measurements with threshold fast neutron detectors enlarge also the proton-recoil spectra measurements, such activation measurements are carried out especially in cases, when a spectrometer cannot be put in the necessary position. The core fission rate distribution is obtained by means of gamma-scanning of the fuel pins. The low noise precise power (flux density) monitoring system, independent of the operation control system, was developed in the LR-0 reactor for mock-up experiments.

  7. Gamma-spectrometry of extended sources for analysing environmental samples

    International Nuclear Information System (INIS)

    Jarosievitz, B.

    1996-01-01

    Measurements of the environmental activity concentration by gamma spectrometers require the determination of the full-energy-peak efficiency as a function of photon energy over the detector range. This can be done by experiments or by calculation. For simple cases, experiments are straightforward, but if the decay scheme is complex, cascade effects modify detection efficiency. Also, actual detection efficiency depends on the detection geometry. All these effects are treated as corrections or modifications of the simple value cases which are especially relevant when applied to large volume of environmental samples. In this thesis calculations are made, using the GEANT MC program, for realistic experimental situations that have been performed, and these calculations are validated. The calculational and experimental results have been compared, and if it proves to be satisfactory, the results can be relied on even for cases when no direct experimental observation is possible. The general problems of gamma spectroscopy and correction problems are discussed. The two main tools, the experimental setup and the simulation program are described. A careful checking of the simulation results and the consequences are presented. (R.P.)

  8. Some aspects related to the high performance in gamma spectrometry

    International Nuclear Information System (INIS)

    Vieru, Gheorghe; Mihaiu, Ramona; Nistor, Viorica

    2010-01-01

    Full text: Gamma spectroscopy is the science (or art) of identification and/or quantification of radionuclides through gamma-ray energy spectrum analysis. It is a recognized technique, well illustrated by the following examples: environmental radioactivity monitoring, health physics personnel monitoring, reactor corrosion monitoring, nuclear materials safeguards and homeland security, as well as nuclear forensics, materials testing, nuclear medicine and radiopharmaceuticals, and industrial process monitoring. Within the Reliability and Testing Laboratory of INR Pitesti there is now available such a detector of high performance that includes all aspects related to cooling, signal processing (with a high resolution) and the dedicated software applications. At the present time, taking into account the 'nuclear renaissance' the new experimental testing laboratories require complete set-up rather than laboratories having a mixture of the old equipment. The paper presents the mechanically cooled HPGe spectrometers with an undergoing rapid evolution, which eliminate traditional intensive liquid nitrogen management. Also, there are described the digital signal processing virtually by eliminating system drift, and, at the same time, requiring recalibrations much less frequently. Another important aspect presented is related to the software applications, which cover a broad spectrum of nuclear measurement techniques. (authors)

  9. Application of Gamma spectrometry for dimensional measurement, by non destructive control, of irradiated nuclear fuel

    International Nuclear Information System (INIS)

    Gleizes, B.

    1993-01-01

    Gamma spectrometry is an efficient tool for measurement of radionuclides activity, but it can be used in a more qualitative way to determine the diameter of gamma radioactive materials. This application has been developed in CENG at Siloe research reactor, particularly for the determination of nuclear fuel swelling when irradiated during normal or incidental conditions. Gamma spectrometry takes place on the measurement of the sample activity profile at the main energy of a fission product, this fission product is chosen for its good cohesion with the fuel. The profile is compared to a simulation on the basis of a calculation in straight line attenuation of gamma radiation; the adjustment of the sample diameter in the calculation is made in order to obtain an agreement between measured and computed profiles. Several parameters can disturb the measurement (gamma emitters distribution in fuel section, radiation scattering...) and make the adjustment of a simulation pattern more difficult. Then it becomes necessary to qualify the method with an irradiated sample calibrated in diameter. (author). 6 figs., 5 refs

  10. 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

  11. 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

  12. Rapid analysis of {sup 226}Ra in waters by {gamma}-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, A.; Martin, P. [Environmental Research Inst. of the Supervising Scientist, Jabiru, NT (Australia)

    1997-05-01

    Techniques for the determination of {sup 226}Ra in waters by {gamma}-ray spectrometry are examined, with an emphasis on methods capable of completion within 1-3 days of sample collection. Methods discussed utilise either: (i) the 186 keV{sup 226}Ra gamma ray, with the contribution from {sup 235}U being subtracted after a separate uranium determination, or (ii) measurement of ingrowing {sup 222}Rn progeny. An analysis of the statistical and systematic errors associated with each technique is presented. Examples are given of their application to analysis of uranium mine process waters. (author).

  13. Determination and quantification of impurities found in samples of 124I using gamma spectrometry

    International Nuclear Information System (INIS)

    Silva, Ronaldo Lins da; Delgado, Jose Ubiratan; Araujo, Miriam Taina Ferreira de; Laranjeira, Adilson da Silva; Poledna, Roberto; Veras, Eduardo de; Almeida, Maria Candida M.; Braghirolli, Ana Maria S.

    2014-01-01

    124 I, positron emitter is produced in the IEN/CNEN-RJ and used in diagnosis image of tumors. In this radioisotope production process impurities appear and health agency requires that the level of these characteristics is quantified. These radionuclides emit gamma and X-radiation, allowing the identification and quantitation by gamma spectrometry. With the use of HPGE detector, coupled with the efficiency curve, was identified 125 I and 126 I. The impurity levels measured in the sample were in the range of 0.5% to 90%, respectively, indicating the feasibility of the method for controlling the quality of the radiopharmaceutical

  14. Portable gamma-ray spectrometry for decommissioning: anywhere, anytime, anything

    Energy Technology Data Exchange (ETDEWEB)

    Attas, M.; Bialas, E. [Atomic Energy of Canada Limited, Pinawa, Manitoba (Canada)

    2010-07-01

    The recent development of extended-source modeling software for portable gamma-ray spectrometers has been a boon to large nuclear projects in the field. This paper reports AECL's experience with such instruments during the first phase of decommissioning the Whiteshell Nuclear Research Establishment (now Whiteshell Laboratories). They have been used for routine measurements of soil cores, for estimates of radionuclide content of waste packages, for surveys of potentially contaminated terrain adjacent to a waste storage facility, and for scans of drums containing likely-clean material. The instruments have been found to be sufficiently sensitive and almost as accurate as laboratory spectrometers using reference sources and calibrated counting geometries. (author)

  15. Statistical modelling of neural networks in {gamma}-spectrometry applications

    Energy Technology Data Exchange (ETDEWEB)

    Vigneron, V.; Martinez, J.M. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Mecanique et de Technologie; Morel, J.; Lepy, M.C. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. des Applications et de la Metrologie des Rayonnements Ionisants

    1995-12-31

    Layered Neural Networks, which are a class of models based on neural computation, are applied to the measurement of uranium enrichment, i.e. the isotope ratio {sup 235} U/({sup 235} U + {sup 236} U + {sup 238} U). The usual method consider a limited number of {Gamma}-ray and X-ray peaks, and require previously calibrated instrumentation for each sample. But, in practice, the source-detector ensemble geometry conditions are critically different, thus a means of improving the above convention methods is to reduce the region of interest: this is possible by focusing on the K{sub {alpha}} X region where the three elementary components are present. Real data are used to study the performance of neural networks. Training is done with a Maximum Likelihood method to measure uranium {sup 235} U and {sup 238} U quantities in infinitely thick samples. (authors). 18 refs., 6 figs., 3 tabs.

  16. 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

  17. 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)

  18. 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)

  19. 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).

  20. 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

  1. 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)

  2. In-situ optical emission spectrometry during galvanostatic aluminum anodising

    International Nuclear Information System (INIS)

    Mercier, D.; Van Overmeere, Q.; Santoro, R.; Proost, J.

    2011-01-01

    In this study, we report on the use of optical emission spectrometry (OES) for the online detection of changes in the Al concentration ejected in a 1.0 mol dm -3 sulphuric acid electrolyte during galvanostatic anodising of Al thin film substrates. The technique relies on the coupling of an Inductively Coupled Plasma (ICP) spectrometer to a specially designed electrochemical flow cell. This has allowed to correlate, for the first time, the kinetics of Al dissolution to well-established morphological changes related to porous anodic oxide formation and growth. A deconvolution algorithm was first developed in order to decompose the experimental ICP/OES signal into elementary distributions, each one characteristic for a specific kinetic regime. The highest dissolution rate systematically occurred during the first step, associated with barrier oxide formation. This is followed by a systematic decrease in the rate of Al dissolution during pore formation. During steady-state porous oxide growth, the Al dissolution rate increases again, but still remains below the level established during barrier oxide growth. In each of these three kinetic regimes, a linear variation of the Al dissolution rate with current density was observed in the range 0.5-5.0 mA cm -2 , with slope values of, respectively, 35 ± 2, 24 ± 2 and 28 ± 1 μg C -1 . Regarding the temporal transitions between the different regimes, a desynchronisation was observed between the kinetic (dissolution) and morphological transitions, the time offset going in opposite directions for barrier and steady-state porous oxide growth. Finally, using the measured Al dissolution rates, the current density dependence of the film formation efficiency for both porous and barrier oxide growth has been established.

  3. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Al-Azmi, Darwish [Department of Applied Sciences, College of Technological Studies, Public Authority for Applied Education and Training, Shuwaikh, P.O. Box: 42325, Code 70654 (Kuwait)]. E-mail: dalazmi@paaet.edu.kw; Karunakara, N. [University Science Instrumentation Centre, Mangalore University, Mangalagangotri 574 199, Mangalore (India)]. E-mail: karunakara_n@yahoo.com

    2007-03-15

    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 {sup 214}Pb and the {sup 214}Bi radon progeny are considered for the detection of the {sup 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.

  5. 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)

  6. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Comparison of two methods of gamma ray spectrometry for analysis of low level radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Melquiades, F.L. [Universidade Estadual do Centro Oeste (UNICENTRO), Guarapuava, PR (Brazil). Dept. de Fisica; Appoloni, C.R. [Universidade Estadual de Londrina, PR (Brazil). Dept. de Fisica

    2002-07-01

    Activity of elements determined by gamma ray spectrometry depends on the total number of counts in the full energy peak of the gamma line. The conventional method that considers the area under the peak is compared with and alternative technique that considers the number of counts at the maximum height of the central channel. The activity of low level radioactivity must have sufficient precision according to national and international norms. Graphical methods are employed for estimating the resolution and the maximum ordinate with low values of systematic errors. Both techniques were applied and compared for the analysis of the {sup 40}K gamma line of 1460.8 keV in powdered milk samples with a H P Ge detector. (author)

  9. 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

  10. A Case Study Correlating Innovative Gamma Ray Scanning Detection Systems Data to Surface Soil Gamma Spectrometry Results - 13580

    International Nuclear Information System (INIS)

    Thompson, Shannon; Rodriguez, Rene; Billock, Paul; Lit, Peter

    2013-01-01

    HydroGeoLogic (HGL), Inc. completed a United States Environmental Protection Agency (USEPA) study to characterize radiological contamination at a site near Canoga Park, California. The characterized area contained 470 acres including the site of a prototype commercial nuclear reactor and other nuclear design, testing, and support operations from the 1950's until 1988 [1]. The site history included radiological releases during operation followed by D and D activities. The characterization was conducted under an accelerated schedule and the results will support the project remediation. The project has a rigorous cleanup to background agenda and does not allow for comparison to risk-based guidelines. To target soil sample locations, multiple lines of evidence were evaluated including a gamma radiation survey, geophysical surveys, historical site assessment, aerial photographs, and former worker interviews. Due to the time since production and decay, the primary gamma emitting radionuclide remaining is cesium-137 (Cs-137). The gamma ray survey covered diverse, rugged terrain using custom designed sodium iodide thallium-activated (NaI(Tl)) scintillation detection systems. The survey goals included attaining 100% ground surface coverage and detecting gamma radiation as sensitively as possible. The effectiveness of innovative gamma ray detection systems was tested by correlating field Cs-137 static count ratios to Cs-137 laboratory gamma spectrometry results. As a case study, the area encompassing the former location of the first nuclear power station in the U. S. was scanned, and second by second global positioning system (GPS)-linked gamma spectral data were evaluated by examining total count rate and nuclide-specific regions of interest. To compensate for Compton scattering from higher energy naturally occurring radionuclides (U-238, Th-232 and their progeny, and K-40), count rate ratios of anthropogenic nuclide-specific regions of interest to the total count rate were

  11. In situ XRF and gamma ray spectrometer for Mars sample return mission

    Science.gov (United States)

    Lo, I. Yin; Trombka, Jacob I.; Evans, Larry G.; Squyres, Steven W.

    1988-01-01

    A combined in situ X-ray fluorescence (XRF) and passive gamma ray spectrometer instrument is proposed for the chemical elemental analysis of various Martian surfaces and samples. The combined instrument can be carried on board a rover. The passive gamma ray or the neutron excited gamma ray system would be used to determine the elemental composition of the Martian surface while the rover is in motion. The XRF system would be used to perform analysis either on the Martian surface or on collected samples when the rover is stationary. The latter function is important both in cataloging the collected samples and in the selection of samples to be returned to earth. For both systems, data accumulation time would be on the order of 30 minutes. No sample preparation would be necessary.

  12. Portable gamma spectrometry with cerium-doped lanthanum bromide scintillators: Suitability assessments for luminescence and electron spin resonance dating applications

    International Nuclear Information System (INIS)

    Arnold, L.J.; Duval, M.; Falguères, C.; Bahain, J.-J.; Demuro, M.

    2012-01-01

    Cerium-doped lanthanum bromide (LaBr 3 :Ce) crystals offer a range of improved scintillation properties over traditional NaI:Tl crystals for in situ gamma spectrometry. At present, however, it remains unclear whether the internal radioactivity of LaBr 3 :Ce detectors compromises their suitability for low-level activity radioisotope measurements of natural sedimentary deposits, such as those required in luminescence and electron spin resonance (ESR) dating. In this study we investigate the suitability of a commercial LaBr 3 :Ce detector for measuring individual concentrations of 40 K, 238 U and 232 Th using predefined ‘energy windows’ from gamma ray spectra. Performance tests have been undertaken using reference materials with well-constrained radioisotope concentrations (the Oxford calibration blocks) and compared with results obtained for a NaI:Tl detector of the same geometry. These tests reveal that the LaBr 3 :Ce detector has a non-negligible intrinsic activity that needs to be accurately quantified prior to measuring any gamma ray spectra in the field. Compared to the NaI:Tl detector, the energy resolution of the LaBr 3 :Ce detector is improved by a factor of two, or more, for the main indicator isotope photopeaks in the 40 K, 238 U and 232 Th decay series. Signal-to-noise ratios for the LaBr 3 :Ce detector show a 25–35% improvement over those of the NaI:Tl detector. In addition, the LaBr 3 :Ce detector is characterised by suitable energy linearity over the full spectral range of interest for the 40 K, 238 U and 232 Th decay series. Replicate gamma ray measurements made with the LaBr 3 :Ce and NaI:Tl detectors for 20 natural sedimentary samples from the Lower Tejo River basin, Portugal, and the Duero River basin, Spain, yield consistent radioisotope concentrations and gamma dose rate estimates. These results are encouraging and suggest that LaBr 3 :Ce detectors can provide suitable estimates of individual radioisotope concentrations in low-level activity

  13. 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

  14. The 2002 IAEA test spectra for low-level {gamma}-ray spectrometry software

    Energy Technology Data Exchange (ETDEWEB)

    Los Arcos, Jose Mo [Laboratorio de Patrones Nacionales, Asociado al C.E.M., CIEMAT, Avda. Complutense 22, Madrid 28040 (Spain); Blaauw, Menno [Interfaculty Reactor Institute, University of Technology Delft, Mekelweg 15, 2629 JB Delft (Netherlands)]. E-mail: blaauw@iri.tudelft.nl; Fazinic, Stjepko [International Atomic Energy Agency, P.O. Box 100, Wagramerstrasse 5, A-1400 Vienna (Austria); Kolotov, Vladimir P. [Institute of Geochemistry and Analytical Chemistry of Russian Academy of Sciences, Kosygin str. 19, Moscow B-334, 117975 (Russian Federation)

    2005-01-01

    Test spectra for low-level {gamma}-ray spectrometry were acquired and made available to the general public at www.iri.tudelft.nl/{approx}rc/fmr/iaea2002. As opposed to the 1995 test spectra, where reference values were made available only for the peak energies and areas, the new set of test spectra was acquired with certified sources, so that the reference values are radionuclide activities. Two well-defined detection geometries were employed: a 500ml Marinelli beaker on a 33% relative efficiency HPGe detector; and a 100ml pillbox on a 96% HPGe detector. The complete set addresses various issues that are especially important in low-level gamma-ray spectrometry, i.e. determination of efficiency curves in the presence of coincidence summing, differences in source geometry and density between standard and sample, poor statistics, shielding of background by the sample, use of low X- or {gamma}-ray energies and the assumption of secular equilibrium of the natural radionuclides. The set was used in an IAEA intercomparison of software packages in December, 2002, reported on in a separate paper.

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

    International Nuclear Information System (INIS)

    Rajput, M.U.

    2007-01-01

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

  16. 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

  17. 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

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

    Science.gov (United States)

    Hizem, N; Ben Fredj, A; Ghedira, L

    2005-01-01

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

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

    Science.gov (United States)

    Wilhelm, Emilien; Gutierrez, Sébastien; Arbor, Nicolas; Ménard, Stéphanie; Nourreddine, Abdel-Mjid

    2016-11-01

    One of the features of the spectra obtained by airborne gamma spectrometry is the low counting statistics due to a short acquisition time (1 s) and a large source-detector distance (40 m) which leads to large statistical fluctuations. These fluctuations bring large uncertainty in radionuclide identification and determination of their respective activities from the window method recommended by the IAEA, especially for low-level radioactivity. Different types of filter could be used on spectra in order to remove these statistical fluctuations. The present work compares the results obtained with filters in terms of errors over the whole gamma energy range of the filtered spectra with the window method. These results are used to determine which filtering technique is the most suitable in combination with some method for total stripping of the spectrum. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. 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

  1. 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

  2. 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

  3. Standardization of Compton suppression gamma spectrometry system for the measurement of 129I in environmental samples

    International Nuclear Information System (INIS)

    Baburajan, A.; Sudheendran, V.; Dalvi, Sushant S.; Ravi, P.M.; Tripathi, R.M.

    2014-01-01

    This paper presents the results of standardization of a Compton Suppression Gamma spectrometry system for the determination of 129 I in various environmental samples in the pathways of Air - grass - milk (thyroid) - Man. The Compton Suppression System consists of an HPGe detector surrounded by an assembly of NaI(Tl) detectors, used to reduce the contribution of scattered gamma rays in the gamma spectrum that originate within the HPGe detector. A Compton suppression system consisting of N-type HPGe detector, 50% relative efficiency having low window thickness of about 0.3μm of Boron, and NaI(TI) detector as Compton shield was commissioned at ESL, Tarapur and various performance parameters were evaluated and documented. Being a reverse electrode HPGe system with low window thickness it can be used for the detection of low energy gamma lines from 3.0 keV to >10 MeV (Ortec). Hence, it is proposed to use the system for the determination of 129 I in environmental samples. The paper deals with the standardization of the system for efficiency and Minimum Detectable Activity (MDA) for various sample geometries in the detection of low level 129 I in various pathways of its exposure

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

    International Nuclear Information System (INIS)

    Yii Mei Wo; Khairul Nizam Razali

    2005-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2017-01-01

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

  6. sup 2 sup 1 sup 0 Pb determination by gamma spectrometry in voluminal samples (cylindrical geometry)

    CERN Document Server

    San Miguel, E G; Bolivar, J P; Garcia-Tenorio, R; Martin, J E

    2002-01-01

    In this paper a simple method for the direct analysis of sup 2 sup 1 sup 0 Pb (T sub 1 sub / sub 2 =22.3 years) by gamma-ray spectrometry in sediment samples with coaxial Ge detectors is outlined. This method, developed for a cylindrical sample geometry, accounts for variable sample heights and provides a fundamental advantage: individual self-absorption corrections can easily be determined knowing the apparent densities of the samples. The results obtained with the proposed method are in good agreement with those given by other techniques.

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

    DEFF Research Database (Denmark)

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

    1999-01-01

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

  8. 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)

  9. 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)

  10. Nuclear Materials Identification System (NMIS) with Gamma Spectrometry for Attributes of Pu, HEU, and Detection of HE and Chemical Agents

    International Nuclear Information System (INIS)

    Mihalczo, J. T.; Mattingly, J. K.; Mullens, J. A.; Neal, J. S.

    2002-01-01

    A combined Nuclear Materials Identification System (NMIS)-gamma ray spectrometry system can be used passively to obtain the following attributes of Pu: presence, fissile mass, 240/239 ratio, and metal vs. oxide. This system can also be used with a small, portable, DT neutron generator to measure the attributes of highly enriched uranium (HEU): presence, fissile mass, enrichment, metal vs. oxide; and detect the presence of high explosives (HE). For the passive system, time-dependent coincidence distributions can be used for the presence, fissile mass, metal vs. oxide for Pu, and gamma-ray spectrometry can be used for 239/240 ratio and presence. So presence can be confirmed by two methods. For the active system with a DT neutron generator, all four attributes for both Pu and HEU can be determined from various features of the time-dependent coincidence distribution measurements for both Pu and HEU. Active gamma ray spectrometry would also give presence and 240/239 ratio for Pu, enrichment for HEU, and metal vs. oxide for both. Active gamma ray spectrometry would determine the presence of HE. The various features of time-dependent coincidence distributions and gamma ray spectrometry that determine these attributes are discussed with some examples from previous determinations

  11. 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)

  12. Water quality - Determination of the activity concentration of radionuclides - Method by high resolution gamma-ray spectrometry. 2. ed.

    International Nuclear Information System (INIS)

    2007-01-01

    This International Standard allows (after proper sampling, sample handling and, when necessary or desirable, sample preparation) the simultaneous determination of the activity concentration of several gamma-ray emitting radionuclides in water samples by gamma-ray spectrometry using high purity germanium [HPGe] detectors. Gamma-ray emitting radionuclides are widespread both as naturally occurring and as man-made radionuclides. Therefore, environmental samples usually contain a multitude of different gamma-ray emitters and high resolution gamma-ray spectrometry provides a useful analytical tool for environmental measurements. Gamma rays cause electron-hole pairs when interacting with matter. When a voltage is applied across a semiconductor detector, these electron hole-pairs are, after proper amplification, detected as current pulses. The pulse height is related to the energy absorbed from the gamma-photon or photons in the resolving time of the detector and electronics. By discriminating between the height of the pulses, a gamma-ray pulse height spectrum is obtained. After analysis of the spectrum, the various peaks are assigned to the radionuclides which emitted the corresponding gamma rays using the previously obtained energy detector calibration. The concentration of the radionuclides present in the sample is calculated using the previously obtained energy dependent detector efficiency. The paper provides information on scope, normative references, terms and conditions, symbols and units, principle, reference sources, reagents, gamma spectrometry equipment, sampling, procedure, expression of results and test report followed by Annex A (Example of a carrier solution which can be added to the water sample when waste water from a nuclear power plant is investigated), Annex B (Calculation of the activity concentration from a gamma spectrum using a linear background subtraction (undisturbed peak) and a bibliography

  13. Time-resolved Neutron-gamma-ray Data Acquisition for in Situ Subsurface Planetary Geochemistry

    Science.gov (United States)

    Bodnarik, Julie G.; Burger, Dan Michael; Burger, A.; Evans, L. G.; Parsons, A. M.; Schweitzer, J. S.; Starr R. D.; Stassun, K. G.

    2013-01-01

    The current gamma-ray/neutron instrumentation development effort at NASA Goddard Space Flight Center aims to extend the use of active pulsed neutron interrogation techniques to probe the subsurface elemental composition of planetary bodies in situ. Previous NASA planetary science missions, that used neutron and/or gamma-ray spectroscopy instruments, have relied on neutrons produced from galactic cosmic rays. One of the distinguishing features of this effort is the inclusion of a high intensity 14.1 MeV pulsed neutron generator synchronized with a custom data acquisition system to time each event relative to the pulse. With usually only one opportunity to collect data, it is difficult to set a priori time-gating windows to obtain the best possible results. Acquiring time-tagged, event-by-event data from nuclear induced reactions provides raw data sets containing channel/energy, and event time for each gamma ray or neutron detected. The resulting data set can be plotted as a function of time or energy using optimized analysis windows after the data are acquired. Time windows can now be chosen to produce energy spectra that yield the most statistically significant and accurate elemental composition results that can be derived from the complete data set. The advantages of post-processing gamma-ray time-tagged event-by-event data in experimental tests using our prototype instrument will be demonstrated.

  14. In-situ gamma-ray measurements in the Chernobyl plume

    Energy Technology Data Exchange (ETDEWEB)

    Lepel, E.A.; Hensley, W.K.; Boatman, J.F.; Busness, K.M.; Davis, W.E.; Robertson, D.E.; Slinn, W.G.N.

    1987-03-01

    Airborne gamma-ray measurements were made aboard the Pacific Northwest Laboratory (PNL) DC-3 and the National Oceanic and Atmospheric Administration (NOAA) King Air research aircraft before and during the first passage of the Chernobyl radioactive cloud over the west coast of the North American continent. Measurements were made from Anchorage, Alaska south to Reno, Nevada. Calculated trajectories were used to estimate the location of the Chernobyl plume. The in-situ gamma-ray analysis systems first detected the cloud on May 8, 1986. Subsequent analysis of concurrently collected air filters indicate that the leading edge of the plume was just reaching the west coast of the United States on May 6, 1986. The ratios of the observed volatile radionuclides (/sup 131/I and /sup 134/Cs) relative to /sup 137/Cs agreed with the reported discharge ratio.

  15. Partial terroir characterisation using rapid in-situ gamma-ray mapping

    Energy Technology Data Exchange (ETDEWEB)

    Newman, R.T.; Joseph, A.D.; Lindsay, R.; Meijer, R.J. de; Maphoto, K.M.; Modisane, T.; Speelman, W. [Environmental Radioactivity Laboratory, iThemba LABS, Somerset West (South Africa)

    2004-07-01

    The term terroir refers to the multitude of factors that influence the character of wine. One such factor is the vineyard soil. Rapid, in-situ measurements of natural radionuclide activity concentrations in vineyard soil in the Stellenbosch region were made using a mobile gamma-ray detector system interfaced with a GPS device. Maps of the total detector count rate (200 keV 3.0 MeV) display significant variation due mainly to the {sup 232}Th activity concentrations present in the soil. Results from an analysis of the correlation between our results and those from traditional chemical analyses of soil samples will be presented. In the light of this the potential for rapid (partial) terroir characterisation using gamma-ray mapping, will be discussed. (author)

  16. Differentiation of three pairs of Boc-beta,gamma- and gamma,beta-hybrid peptides by electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Ramesh, V; Srinivas, R; Sharma, G V M; Jayaprakash, P; Kunwar, A C

    2008-09-01

    A new series of Boc-N-beta(3), gamma(4)-/gamma(4), beta(3)-isomeric hybrid peptides (containing repeats of beta(3)-Caa and gamma(4)-Caa's, Caa = C-linked carbo beta(3)-/gamma(4)-amino acids derived from D-xylose) have been differentiated by both positive and negative ion electrospray ionization (ESI) ion-trap and high resolution quadrupole time-of-flight/tandem mass spectrometry (Q-TOF MS/MS). MS(n) of protonated isomeric peptides and [M+H-Boc+H](+) produce characteristic fragmentation involving the peptide backbone, the Boc-group, and the side chain. The positional isomers are differentiated from one another by the presence of y(n)(+), b(n)(+), and other fragment ions of different m/z values. It is observed that the peptides with beta-Caa at the N-terminus produce extensive fragmentation, whereas gamma-Caa gave rise to much less fragmentation. Peptides with gamma-Caa at the N-terminus lose NH(3), whereas this process is absent for the carbopeptides with beta-Caa at the N-terminus. Two pairs of dipeptide diastereomers are clearly differentiated by the collision-induced dissociation (CID) of their protonated molecules. The loss of 2-methylprop-1-ene is more pronounced for Boc-NH-(R)-beta-Caa-(R)-gamma-Caa-OCH(3) (6) and Boc-NH-(R)-gamma-Caa-(R)-beta-Caa-OCH(3) (12), whereas it is insignificant or totally absent for its protonated diastereomeric pair Boc-NH-(S)-beta-Caa-(S)-gamma-Caa-OCH(3) (1) and Boc-NH-(S)-gamma-Caa-(S)-beta-Caa-OCH(3) (7). Further, ESI negative ion tandem mass spectrometry has also been found to be useful for differentiating these isomeric peptide acids.

  17. In situ measurement of some gamma-emitting radionuclides in plant communities of the South Carolina coastal plain

    International Nuclear Information System (INIS)

    Ragsdale, H.L.; Tanner, B.K.; Coleman, R.N.; Palms, J.M.; Wood, R.E.

    1978-01-01

    In situ and laboratory gamma-ray spectroscopy measurements were taken in nine scrub oak forests and nine old fields to determine the applicability of in situ analysis in the coastal plain. Data collected at each of the 18 sites included a 2-hr count, soil density and moisture estimates, and vegetation measurements. Samples returned to the laboratory for radiometric analysis included litter and herbaceous vegetation and soil cores. Analysis of the gamma-emitter detection frequencies, concentrations, and burdens showed good to excellent agreement between laboratory and in situ methods. Generally, forests were determined to be superior in situ sampling systems. Laboratory analysis of collected samples may be a superior technique for gamma emitters with low energies, low concentrations, or nonuniform distributions in the soil. Three potential uses of in situ Ge(Li) spectrometers were identified and discussed in terms of their limits and of the replicate ecosystems appropriate for in situ analyses. Although the variety and the biogeochemical cycling regimes of southeastern coastal plain ecosystems complicate in situ analyses, it was concluded that comparable and probably accurate results can be achieved using in situ technology

  18. 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.

  19. Determination of {sup 7}BE in soil sample by gamma spectrometry for erosion researchs

    Energy Technology Data Exchange (ETDEWEB)

    Esquivel, Alexander D., E-mail: alexander.esquivel@utp.ac.pa [Centro de Investigaciones Hidraulicas e Hidrotecnicas (CIHH/UTP-PA), Universidad Tecnologica de Panama (Panama); Kastner, Geraldo F.; Amaral, Angela M.; Monteiro, Roberto Pellacani G.; Moreira, Rubens M., E-mail: gfk@cdtn.br, E-mail: ama@cdtn.br, E-mail: rpgm@cdtn.br, E-mail: rubens@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    Cosmogenic {sup 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 {sup 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. {sup 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 {sup 228}Ac (E{sub γ} = 478.40 keV, T½ = 6.15h) interference. The aim of this work was to establish an analytical protocol for the {sup 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 {sup 228}Ac in the {sup 7}Be activity measurements by gamma spectrometry. (author)

  20. A simple screening method for the determination of 230Th in soil and sediment samples by gamma-spectrometry

    International Nuclear Information System (INIS)

    Lozano, J.C.; Rodriguez, P.B.; Tome, F.V.

    2001-01-01

    A simple and easy to perform method for the determination of 230 Th in soil and sediment samples using gamma-spectrometry is proposed and compared with the more usual procedure using alpha-particle spectrometry. The proposed method involves an efficiency calibration for the specific determination of this radionuclide instead of a complete calibration of the spectra. A single density parameter is introduced to correct the efficiencies obtained from the reference sources. The activities of 230 Th determined by gamma-spectrometry and alpha-particle spectrometry are compared. The minimum detectable activity values obtained are completely adequate for 230 Th determination in soil and sediment samples, in which 230 Th activities are usually fairly high. Thus, this procedure is intended as a very easy way to obtain the activity of this radionuclide in these types of samples, at least as a screening method before carrying out other more laborious procedures. (author)

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

    International Nuclear Information System (INIS)

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

    1996-11-01

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

  2. 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.

  3. Volatiles emitted from flowers by gamma-radiated and nonradiated Jasminum polyanthum Franch. in situ

    International Nuclear Information System (INIS)

    Christensen, L.P.; Jakobsen, H.B.; Kristiansen, K.; Moller, J.

    1997-01-01

    Volatile compounds emitted from flowers of Jasminum polyanthum Pepita in situ were collected by dynamic headspace technique and analyzed by GC-FID and GC-MS. A total of 32 compounds were identified. The flower scent was dominated by benzyl acetate (57.8%), p-cresol (12.2%), (E)-isoeugenol (9.7%), eugenol (3.5%), 2-methoxy-p-cresol (3.1%), linalool (3.0%), phenethyl acetate (2.1%), and (Z)3-hexenyl butyrate (1.9%). The strong scent of Pepita reduces its production potentialities as a pot plant, thus the possibility to reduce or modify the emission of volatiles from Pepita by mutagenesis was investigated. The average total yields of volatiles in Pepita were approximately 2800 ng flower-1 h-1, and in one gamma-radiated clone a significantly lower yield of 1050 ng flower-1 h-1 was found. The volatile profiles of the gamma-radiated plants were made up of the same 32 compounds found in Pepita. Significant differences in the headspace composition between Pepita and gamma-radiated plants were found for some of the major volatiles

  4. Fission Product Inventory and Burnup Evaluation of the AGR-2 Irradiation by Gamma Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Harp, Jason Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Stempien, John Dennis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Demkowicz, Paul Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    Gamma spectrometry has been used to evaluate the burnup and fission product inventory of different components from the US Advanced Gas Reactor Fuel Development and Qualification Program's second TRISO-coated particle fuel irradiation test (AGR-2). TRISO fuel in this irradiation included both uranium carbide / uranium oxide (UCO) kernels and uranium oxide (UO2) kernels. Four of the 6 capsules contained fuel from the US Advanced Gas Reactor program, and only those capsules will be discussed in this work. The inventories of gamma-emitting fission products from the fuel compacts, graphite compact holders, graphite spacers and test capsule shell were evaluated. These data were used to measure the fractional release of fission products such as Cs-137, Cs-134, Eu-154, Ce-144, and Ag-110m from the compacts. The fraction of Ag-110m retained in the compacts ranged from 1.8% to full retention. Additionally, the activities of the radioactive cesium isotopes (Cs-134 and Cs-137) have been used to evaluate the burnup of all US TRISO fuel compacts in the irradiation. The experimental burnup evaluations compare favorably with burnups predicted from physics simulations. Predicted burnups for UCO compacts range from 7.26 to 13.15 % fission per initial metal atom (FIMA) and 9.01 to 10.69 % FIMA for UO2 compacts. Measured burnup ranged from 7.3 to 13.1 % FIMA for UCO compacts and 8.5 to 10.6 % FIMA for UO2 compacts. Results from gamma emission computed tomography performed on compacts and graphite holders that reveal the distribution of different fission products in a component will also be discussed. Gamma tomography of graphite holders was also used to locate the position of TRISO fuel particles suspected of having silicon carbide layer failures that lead to in-pile cesium release.

  5. 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

  6. 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.

  7. Seven years of gamma-ray spectrometry interlaboratory comparisons in Switzerland

    International Nuclear Information System (INIS)

    Bailat, Claude; Buchillier, Thierry; Caffari, Yvan; Nedjadi, Youcef; Spring, Philippe; Estier, Sybille; Bochud, Francois

    2010-01-01

    Since the 1990s, regular comparisons of gamma-ray spectrometry in Switzerland were organized to improve laboratory abilities to measure the radioactivity in the environment and food stuffs at typical routine levels. The activity concentration of the test samples and the evaluation of the associated uncertainties remained each year the main required test result. Over the years, the comparisons used certified reference solutions as well as environmental samples. The aim of this study is to research the effect of the comparisons on measurement quality. An analysis of the seven last interlaboratory comparisons revealed that the Swiss measurement capability is up to date. In addition, the results showed that the participants now have an improved evaluation of the uncertainties associated with their measurement.

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

    Science.gov (United States)

    Vidmar, Tim; Korun, Matjaž

    2006-01-01

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

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

    International Nuclear Information System (INIS)

    Lopez, Luis E.

    1998-01-01

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

  10. The application of computer technique in routine neutron activation analysis using high resolution gamma ray spectrometry

    International Nuclear Information System (INIS)

    Szopa, Z.; Plejewska, M.; Staszelis, J.

    1982-01-01

    A full system of four computer programs for routine - qualitative and quantitative - neutron activation analysis (NAA) using high resolution gamma ray-spectrometry had been elaborated. The structure and possibilities of the ''data flow'' programs i.e. programs DIDPDP and DIDCDC, dedicated for fast and reliable ''off line'' data transfer between the buffer memory of the spectrometric line (9-track magnetic tape) and the fast access memory (disc) of the used computers PDP-11/45 and CYBER-73 had been presented. The structure and organization of the ''data processing'' programs i.e. programs SAWAPS and MAZYG had been presented as well. The utility and reliability of these programs in the case of the large-scale, routine NAA, exampled by analysis of filters with air polutants, had been tested and discussed. Programs are written mainly in FORTRAN. (author)

  11. 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)

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  13. 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)

  14. Reliability and performances of a high-purity gamma spectrometry system used for environmental measurements

    International Nuclear Information System (INIS)

    Ileana Radulescu; Marian Romeo Calin

    2014-01-01

    Proficiency testing is among the most methods to assess the accuracy of the analytical data produced by laboratories. The results presented in this paper show the performance of the laboratory for three intercomparisons organized by Radionuclide Metrology Laboratory (RML) and by IAEA, in which SALMROM laboratory have participated in three consecutive years. The feedbacks from the final reports from RML and IAEA demonstrate the performance of the laboratory where 34 out of 39 pass all acceptance criteria of the test. The rest of five results which failed served to improve the laboratory analysis and to optimize accuracy measurements. The overall results of the proficiency tests point out the reliability and traceability of the gamma spectrometry system used for environmental measurements. (author)

  15. 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)

  16. Fast in situ gamma spectroscopy using hand-held spectrometer with NaI probe.

    Science.gov (United States)

    Guguła, Szymon; Kozak, Krzysztof; Mazur, Jadwiga; Grządziel, Dominik; Mroczek, Mariusz

    2018-08-01

    In this work a hand-held spectrometer InSpector 1000 with NaI (Tl) 2″ x 2″ detector has been adapted to fast in situ gamma-ray spectroscopy. Two specially designed mounting stands with shielding have been built, allowing conducting measurements in different geometries. Three particular geometries (NW, IS50, IS00) have been chosen for efficiency calibration and further study. The first one (NW) is intended for small environmental samples (volume ca 140 cm 3 ) collected on site. IS50 geometry is a typical in situ geometry meant for radioactivity measurements in soil with detector pointed towards the ground. In this geometry the probe is shielded and mounted 50 cm above the soil surface. The new proposed geometry IS00 is designed in the way that the detector is inserted directly into the soil in order to increase the counting efficiency. The methods of efficiency calibration involved using calibration standards (in NW geometry) and the results obtained in previous in situ measurements with InSpector 2000 portable spectrometer with HPGe detector and ISOCS™ Shield Systems, which is routinely used in environmental measurements. NW geometry turned out to be useful for natural radioisotopes concentrations (K-40, U-238 and Th-232), which significantly exceed typical values of those concentrations observed in Poland. Both IS50 and IS00 geometries are applicative for quick (2 h long measurement) evaluation of typical concentrations of K, U and Th in soils. The newly proposed geometry IS00 is superior as it showed lower detection limits and uncertainties as well as its handling was far easier than of IS50. Authors have proven that hand-held spectrometer InSpector 1000, together with mounting stands and shielding, can be successfully used for fast in situ gamma-spectroscopy. Its relatively small weight and good mobility are additional assets. Moreover, detailed procedures for measurements in each geometry have been developed to conduct such analyses properly. Copyright

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

    International Nuclear Information System (INIS)

    Soares, A.J.

    1977-01-01

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

  18. Gamma ray evaluation of fast neutron irradiated on topaz from Sri Lanka by HPGe gamma ray spectrometry

    Science.gov (United States)

    Boonsook, K.; Kaewwiset, W.; Limsuwan, P.; Naemchanthara, K.

    2017-09-01

    The purpose of this study was to evaluate the radionuclide concentrations of London blue topaz after fast neutron irradiation. The London blue topaz was obtained from Sri Lanka which classified into dark and light colors in the shape of an oval and rectangle with small, medium and large size. The optical property and radionuclide concentrations of London blue topaz have been examine by UV-Visible spectroscopy and HPGe gamma ray spectrometry, respectively. The UV-absorption spectra of topaz was taken in the range of 300 to 800 nm at room temperature. The results showed that the absorption peak of topaz was observed with only broad peaks in the range of 550 to 700 nm and 630 nm that correlated to the O - center in hydroxyl sites which substitutes for fluorine in topaz structure. The radioactivity of dark and light colors in the shape of an oval and rectangle London blue topaz was in the range of 1.437 ± 0.014 to 21.551 ± 0.037 nCi/g (oval dark), 2.958 ± 0.031 to 6.748 ± 0.054 nCi/g (oval light) and 2.350 ± 0.014 to 43.952 ± 0.088 nCi/g (rectangle dark), 1.442 ± 0.023 to 6.748 ± 0.054 nCi/g (rectangle light), respectively. The decay rates of 46Sc, 182Ta and 54Mn isotopes created by irradiation showed that the decay time of the radioactive element depended on the size of the topaz so increased with decreasing the size of topaz. Moreover, the size of topaz also affect the absorption coefficient. This study is applied to predict time of residue dose of topaz for enhancement colorless topaz by neutron radiation treatment.

  19. Laser Time-of-Flight Mass Spectrometry for Future In Situ Planetary Missions

    Science.gov (United States)

    Getty, S. A.; Brinckerhoff, W. B.; Cornish, T.; Ecelberger, S. A.; Li, X.; Floyd, M. A. Merrill; Chanover, N.; Uckert, K.; Voelz, D.; Xiao, X.; hide

    2012-01-01

    Laser desorption/ionization time-of-flight mass spectrometry (LD-TOF-MS) is a versatile, low-complexity instrument class that holds significant promise for future landed in situ planetary missions that emphasize compositional analysis of surface materials. Here we describe a 5kg-class instrument that is capable of detecting and analyzing a variety of analytes directly from rock or ice samples. Through laboratory studies of a suite of representative samples, we show that detection and analysis of key mineral composition, small organics, and particularly, higher molecular weight organics are well suited to this instrument design. A mass range exceeding 100,000 Da has recently been demonstrated. We describe recent efforts in instrument prototype development and future directions that will enhance our analytical capabilities targeting organic mixtures on primitive and icy bodies. We present results on a series of standards, simulated mixtures, and meteoritic samples.

  20. 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)

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

    Science.gov (United States)

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

    2016-01-01

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

  2. Development of experimental in-situ Pu monitoring system based on passive gamma spectroscopy technique

    International Nuclear Information System (INIS)

    Kulkarni, C.P.; Vinod, M.; Paulson, M.; Das, D.; Ananthakrishnan, T.S.; Pithawa, C.K.; Debdas, A.; Udagatti, S.V.; Singh, Pratap; Rajendra Kumar

    2013-01-01

    To meet the requirements of in-situ 239 Pu monitoring at various stages of fuel reprocessing for NRB, an indigenous Pu monitoring system is developed by Electronics Division, BARC. The system is based on passive gamma spectroscopy technique and utilizes an advanced scintillation detector along-with compact spectroscopy hardware. The system hardware and application software have been installed at Control Lab, PREFRE-2, Tarapur for testing and evaluation. Quantification accuracy of better than 10% is achieved during the initial phase of evaluation. The system is targeted for quantification of Pu in samples drawn from Pu purification cycles with operational frequency of 3-5 samples in Round-The-Clock shifts. The system will significantly minimize manual handling of Pu samples in comparison with the existing methods. (author)

  3. 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

  4. MALDI Mass Spectrometry Imaging for Visualizing In Situ Metabolism of Endogenous Metabolites and Dietary Phytochemicals

    Directory of Open Access Journals (Sweden)

    Yoshinori Fujimura

    2014-05-01

    Full Text Available Understanding the spatial distribution of bioactive small molecules is indispensable for elucidating their biological or pharmaceutical roles. Mass spectrometry imaging (MSI enables determination of the distribution of ionizable molecules present in tissue sections of whole-body or single heterogeneous organ samples by direct ionization and detection. This emerging technique is now widely used for in situ label-free molecular imaging of endogenous or exogenous small molecules. MSI allows the simultaneous visualization of many types of molecules including a parent molecule and its metabolites. Thus, MSI has received much attention as a potential tool for pathological analysis, understanding pharmaceutical mechanisms, and biomarker discovery. On the other hand, several issues regarding the technical limitations of MSI are as of yet still unresolved. In this review, we describe the capabilities of the latest matrix-assisted laser desorption/ionization (MALDI-MSI technology for visualizing in situ metabolism of endogenous metabolites or dietary phytochemicals (food factors, and also discuss the technical problems and new challenges, including MALDI matrix selection and metabolite identification, that need to be addressed for effective and widespread application of MSI in the diverse fields of biological, biomedical, and nutraceutical (food functionality research.

  5. MALDI Mass Spectrometry Imaging for Visualizing In Situ Metabolism of Endogenous Metabolites and Dietary Phytochemicals

    Science.gov (United States)

    Fujimura, Yoshinori; Miura, Daisuke

    2014-01-01

    Understanding the spatial distribution of bioactive small molecules is indispensable for elucidating their biological or pharmaceutical roles. Mass spectrometry imaging (MSI) enables determination of the distribution of ionizable molecules present in tissue sections of whole-body or single heterogeneous organ samples by direct ionization and detection. This emerging technique is now widely used for in situ label-free molecular imaging of endogenous or exogenous small molecules. MSI allows the simultaneous visualization of many types of molecules including a parent molecule and its metabolites. Thus, MSI has received much attention as a potential tool for pathological analysis, understanding pharmaceutical mechanisms, and biomarker discovery. On the other hand, several issues regarding the technical limitations of MSI are as of yet still unresolved. In this review, we describe the capabilities of the latest matrix-assisted laser desorption/ionization (MALDI)-MSI technology for visualizing in situ metabolism of endogenous metabolites or dietary phytochemicals (food factors), and also discuss the technical problems and new challenges, including MALDI matrix selection and metabolite identification, that need to be addressed for effective and widespread application of MSI in the diverse fields of biological, biomedical, and nutraceutical (food functionality) research. PMID:24957029

  6. On-line interrogation of pebble bed reactor fuel using passive gamma-ray spectrometry

    Science.gov (United States)

    Chen, Jianwei

    The Pebble Bed Reactor (PBR) is a helium-cooled, graphite-moderated high temperature nuclear power reactor. In addition to its inherently safe design, a unique feature of this reactor is its multipass fuel cycle in which graphite fuel pebbles (of varying enrichment) are randomly loaded and continuously circulated through the core until they reach their prescribed end-of-life burnup limit (˜80,000--100,000 MWD/MTU). Unlike the situation with conventional light water reactors (LWRs), depending solely on computational methods to perform in-core fuel management will be highly inaccurate. As a result, an on-line measurement approach becomes the only accurate method to assess whether a particular pebble has reached its end-of-life burnup limit. In this work, an investigation was performed to assess the feasibility of passive gamma-ray spectrometry assay as an approach for on-line interrogation of PBR fuel for the simultaneous determination of burnup and enrichment on a pebble-by-pebble basis. Due to the unavailability of irradiated or fresh pebbles, Monte Carlo simulations were used to study the gamma-ray spectra of the PBR fuel at various levels of burnup. A pebble depletion calculation was performed using the ORIGEN code, which yielded the gamma-ray source term that was introduced into the input of an MCNP simulation. The MCNP simulation assumed the use of a high-purity coaxial germanium detector. Due to the lack of one-group high temperature reactor cross sections for ORIGEN, a heterogeneous MCNP model was developed to describe a typical PBR core. Subsequently, the code MONTEBURNS was used to couple the MCNP model and ORIGEN. This approach allowed the development of the burnup-dependent, one-group spectral-averaged PBR cross sections to be used in the ORIGEN pebble depletion calculation. Based on the above studies, a relative approach for performing the measurements was established. The approach is based on using the relative activities of Np-239/I-132 in combination

  7. 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.

  8. Statistical signal processing for gamma spectrometry: application for a pileup correction method; Traitement statistique du signal spectrometrique: etude du desempilement de spectre en energie pour la spectrometrie gamma

    Energy Technology Data Exchange (ETDEWEB)

    Trigano, T

    2005-12-15

    The main objective of gamma spectrometry is to characterize the radioactive elements of an unknown source by studying the energy of the emitted photons. When a photon interacts with a detector, its energy is converted into an electrical pulse. The histogram obtained by collecting the energies can be used to identify radioactive elements and measure their activity. However, at high counting rates, perturbations which are due to the stochastic aspect of the temporal signal can cripple the identification of the radioactive elements. More specifically, since the detector has a finite resolution, close arrival times of photons which can be modeled as an homogeneous Poisson process cause pile-ups of individual pulses. This phenomenon distorts energy spectra by introducing multiple fake spikes and prolonging artificially the Compton continuum, which can mask spikes of low intensity. The objective of this thesis is to correct the distortion caused by the pile-up phenomenon in the energy spectra. Since the shape of photonic pulses depends on many physical parameters, we consider this problem in a nonparametric framework. By introducing an adapted model based on two marked point processes, we establish a nonlinear relation between the probability measure associated to the observations and the probability density function we wish to estimate. This relation is derived both for continuous and for discrete time signals, and therefore can be used on a large set of detectors and from an analog or digital point of view. It also provides a framework to this problem, which can be considered as a problem of nonlinear density deconvolution and nonparametric density estimation from indirect measurements. Using these considerations, we propose an estimator obtained by direct inversion. We show that this estimator is consistent and almost achieves the usual rate of convergence obtained in classical nonparametric density estimation in the L{sup 2} sense. We have applied our method to a set

  9. Het meten van radioactieve bodembesmettingen vanuit de lucht. Gebruik van de in-situ gammaspectrometriemethode

    NARCIS (Netherlands)

    Loman AC; ter Kuile CR; Slaper H

    1990-01-01

    In-situ gamma spectrometry can be used to determine the qualitative and quantitative deposition of radioactive materials on the ground surface. By applying the in-situ spectrometry method using either a helicopter or an airplane, large areas can be scanned in a short period of time. In this report

  10. Laser-based mass spectrometry for in situ chemical composition analysis of planetary surfaces

    Science.gov (United States)

    Frey, Samira; Neuland, Maike B.; Grimaudo, Valentine; Moreno-García, Pavel; Riedo, Andreas; Tulej, Marek; Broekmann, Peter; Wurz, Peter

    2016-04-01

    Mass spectrometry is an important analytical technique in space research. The chemical composition of planetary surface material is a key scientific question on every space mission to a planet, moon or asteroid. Chemical composition measurements of rocky material on the surface are of great importance to understand the origin and evolution of the planetary body.[1] A miniature laser ablation/ionisation reflectron- type time-of-flight mass spectrometer (instrument name LMS) was designed and built at the University of Bern for planetary research.[2] Despite its small size and light weight, the LMS instrument still maintains the same capabilities as large laboratory systems, which makes it suitable for its application on planetary space missions.[3-5] The high dynamic range of about eight orders of magnitude, high lateral (μm-level) and vertical (sub-nm level) resolution and high detection sensitivity for almost all elements (10 ppb, atomic fraction) make LMS a versatile instrument for various applications. LMS is a suitable instrument for in situ measurements of elemental and isotope composition with high precision and accuracy. Measurements of Pb- isotope abundances can be used for dating of planetary material. Measurements of bio-relevant elements allow searching for past or present life on a planetary surface. The high spatial resolution, both in lateral and vertical direction, is of considerable interest, e.g. for analysis of inhomogeneous, extraterrestrial samples as well as weathering processes of planetary material. References [1] P. Wurz, D. Abplanalp, M. Tulej, M. Iakovleva, V.A. Fernandes, A. Chumikov, and G. Managadze, "Mass Spectrometric Analysis in Planetary Science: Investigation of the Surface and the Atmosphere", Sol. Sys. Res., 2012, 46, 408. [2] U. Rohner, J.A. Whitby, P. Wurz, "A miniature laser ablation time of flight mass spectrometer for in situ planetary exploration" Meas. Sci. Tch., 2003, 14, 2159. [3] M. Tulej, A. Riedo, M.B. Neuland, S

  11. 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,

  12. Determination of difficult-to-measure Niobium-94 in nuclear wastes using extraction chromatography and gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Temba, Eliane S.C.; Kastner, Geraldo F.; Reis Junior, Aluisio S.; Monteiro, Roberto P.G.; Moreira, Rubens M., E-mail: esct@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    A radiochemical methodology for {sup 94}Nb determination in low-level radioactive wastes from nuclear power plant was proposed. Although it is a strong gamma emitter its concentration in radioactive waste samples are usually several orders of magnitude lower than that of other β-γ emitters, whose emissions affect the emission lines of {sup 94}Nb. The procedure involves extraction chromatography by using TEVA resin to isolate the Nb nuclide and the gamma spectrometry to its measurement. The chemical yield was around 75%. Samples of evaporator concentrate and spent resin were analyzed. (author)

  13. 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.)

  14. Detection and evaluation of uranium in different minerals by gamma spectrometry and laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sergani, F.M.; Khedr, M.A.; Harith, M.A. [National Inst. of Laser Enhanced Sciences (NILES), Cairo Univ. (Egypt); El Mongy, S.A. [National Center for Nuclear Safety, Atomic Energy Authority, Nasr City, Cairo (Egypt)

    2004-07-01

    Analysis, detection and evaluation of source nuclear materials (e.g. uranium) in different minerals by sensitive techniques are a vital objective for uranium exploration, nuclear materials extraction, processing and verification. In this work, uranium in different geological formations was determined using gamma spectrometry and laser induced breakdown spectroscopy (LIBS). The investigated samples were collected from different regions distributed all over Egypt. The samples were then prepared for non-destructive analysis. A hyper pure germanium detector was used to measure the emitted gamma rays of uranium and its daughters in the samples. The concentrations of uranium in ppm ({mu}g/g) in the investigated samples are given and discussed in this work. The highest uranium concentration (4354.9 ppm) was found in uranophane samples of Gattar rocks. In Laser induced breakdown spectroscopy (LIBS) technique, plasma was formed by irradiating the rock surface with focused Q-switched Nd:Yag laser pulses of 7 ns pulse duration at the fundamental wavelength (1064 nm). Atoms and ions originating from the rock surface are excited and ionized in the laser produced hot plasma ({proportional_to}10 000 K). The plasma emission spectral line is characteristic of the elements present in the plasma and allows identification of the uranium in the uranophane mineral. The strong atomic line at 424.2 nm is used for the qualitative identification of uranium. It can be mentioned that the elevated levels of uranium in some of the investigated uranophane samples are of great economic feasibility to be extracted. (orig.)

  15. An analysis of the potassium concentrations of soft drinks by HPGe gamma spectrometry

    International Nuclear Information System (INIS)

    Guillermo Espinosa; Jose-Ignacio Golzarri; Ilsa Hernandez-Ibinarriaga

    2009-01-01

    Potassium, in a variety of compounds, occurs in abundance in the Earth's crust, and is an essential nutrient for human health. A naturally occurring radioactive isotope of potassium, 40 K, is found in the food and water that we consume. This paper presents the results of a gamma spectrometry analysis of the 40 K concentrations of a selection of commercial soft drinks. The 40 K concentrations are used to calculate the overall potassium concentrations. The analysis was carried out using a hyper-pure germanium (HPGe) detector with Ortec R ASPEC-927 multichannel analyzer module and GammaVision R software. This system was chosen for its high resolution and automatic data processing. The carbonated soft drinks (sodas) Coca-Cola R , Coca-Cola Light R (sold as Diet Coke R in the USA and other countries), Coca-Cola Zero R , Pepsi R , Pepsi Light R , Pepsi Max R , Big Cola R , Lulu-Cola R , Manzana Lift R , Sprite R and Fanta R and the mineral waters Ciel R and Penafiel R were analyzed. These brands are all international registered trademarks. The products analyzed were manufactured and bottled in Mexico. The results show a great variety of potassium concentrations in the different soft drinks analyzed (from 128.0 to 1113.1 mg/L). The concentration of potassium in the sodas, in conjunction with the amounts drank by one person in a year (180 L/year), are high enough to warrant consideration by public health authorities and by people to whom high potassium intakes pose a risk. (author)

  16. Gamma spectrometry of EFTTRA T2BIS R280.2. Gamma scan wires 6 through 10

    International Nuclear Information System (INIS)

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

    1996-11-01

    In the frame work of the EFTTRA programme on recycling of actinides and fission products, five gamma scan wires which were included in the experiment R280.2 T2bis have been examined by gamma scanning. The results of the measurements have been described in this report. (orig.)

  17. 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)

  18. MALDI imaging mass spectrometry for in situ proteomic analysis of preneoplastic lesions in pancreatic cancer.

    Directory of Open Access Journals (Sweden)

    Barbara M Grüner

    Full Text Available The identification of new biomarkers for preneoplastic pancreatic lesions (PanINs, IPMNs and early pancreatic ductal adenocarcinoma (PDAC is crucial due to the diseases high mortality rate upon late detection. To address this task we used the novel technique of matrix-assisted laser desorption/ionization (MALDI imaging mass spectrometry (IMS on genetically engineered mouse models (GEM of pancreatic cancer. Various GEM were analyzed with MALDI IMS to investigate the peptide/protein-expression pattern of precursor lesions in comparison to normal pancreas and PDAC with cellular resolution. Statistical analysis revealed several discriminative m/z-species between normal and diseased tissue. Intraepithelial neoplasia (PanIN and intraductal papillary mucinous neoplasm (IPMN could be distinguished from normal pancreatic tissue and PDAC by 26 significant m/z-species. Among these m/z-species, we identified Albumin and Thymosin-beta 4 by liquid chromatography and tandem mass spectrometry (LC-MS/MS, which were further validated by immunohistochemistry, western blot, quantitative RT-PCR and ELISA in both murine and human tissue. Thymosin-beta 4 was found significantly increased in sera of mice with PanIN lesions. Upregulated PanIN expression of Albumin was accompanied by increased expression of liver-restricted genes suggesting a hepatic transdifferentiation program of preneoplastic cells. In conclusion we show that GEM of endogenous PDAC are a suitable model system for MALDI-IMS and subsequent LC-MS/MS analysis, allowing in situ analysis of small precursor lesions and identification of differentially expressed peptides and proteins.

  19. Towards matrix-free femtosecond-laser desorption mass spectrometry for in situ space research.

    Science.gov (United States)

    Moreno-García, Pavel; Grimaudo, Valentine; Riedo, Andreas; Tulej, Marek; Wurz, Peter; Broekmann, Peter

    2016-04-30

    There is an increasing interest in the quest for low molecular weight biomarkers that can be studied on extra-terrestrial objects by direct laser desorption mass spectrometry (LD-MS). Although molecular structure investigations have recently been carried out by direct LD-MS approaches, there is still a lack of suitable instruments for implementation on a spacecraft due to weight, size and power consumption demands. In this contribution we demonstrate the feasibility of LD-MS structural analysis of molecular species by a miniature laser desorption-ionization mass spectrometer (instrument name LMS) originally designed for in situ elemental and isotope analysis of solids in space research. Direct LD-MS studies with molecular resolution were carried out by means of a Laser Ablation/Ionization Mass Spectrometry (LIMS) technique. Two polymer samples served as model systems: neutral polyethylene glycol (PEG) and cationic polymerizates of imidazole and epichlorohydrin (IMEP). Optimal conditions for molecular fragmentation could be identified for both polymers by tuning the laser energy and the instrument-sample distance. PEG and IMEP polymers show sufficient stability over a relatively wide laser energy range. Under mild LD conditions only moderate fragmentation of the polymers takes place so that valuable structural characterization based on fragment ions can be achieved. As the applied laser pulse energy rises, the abundance of fragment ions increases, reaches a plateau and subsequently drops down due to more severe fragmentation and atomization of the polymers. At this final stage, usually referred to as laser ablation, only elemental/isotope analysis can be achieved. Our investigations demonstrate the versatility of the LMS instrument that can be tuned to favourable laser desorption conditions that successfully meet molecule-specific requirements and deliver abundant fragment ion signals with detailed structural information. Overall, the results show promise for use in

  20. 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

  1. Gamma spectrometry in the Osiris reactor. Determination of the power and burn-up rate of irradiated fuel element

    International Nuclear Information System (INIS)

    Destot, M.; Musso, J.F.; Cerles, J.M.

    1976-01-01

    The gamma spectrometry facility, original in design, located in the immediate proximity of the OSIRIS reactor core at Saclay, is described. This device is used to examine nuclear fuel elements irradiated in OSIRIS or in some power reactors. In most cases, it is possible to equip power reactors (in particular water reactors) with installations of this type. With this device, it is also possible to follow the evolution of a large number of fission products in space and time, and to obtain useful information concerning nuclear safety (for example, cladding rupture) and fuel economy (with burn-up rate determination). Details on the performance of this measuring device are given in connection with the study of burn-up rates and linear irradiation power. This OSIRIS reactor gamma spectrometry installation is a nondestructive testing technique, which is easy and rapid to use [fr

  2. 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

  3. Gamma ray fluorescence for in situ evaluation of ore in Witwatersrand gold mines

    International Nuclear Information System (INIS)

    Rolle, R.

    1979-01-01

    A system for quantitative in situ evaluation of ore in Witwatersrand gold mines was researched and subsequently developed. The principle of measurement is based on the excitation of gold K X-rays in rock face samples by the 88 keV gamma radiation from a Cadmium-109 radioisotope source. The X-rays and scattered radiation from the rock matrix are detected by a hyperpure germanium detector cooled by liquid nitrogen in a portable probe. In the fluorescence spectrum the intensity ratio of the gold Kβ peaks to their immediate scattered background is evaluated and quantitatively converted in the portable analyser to area concentration units. All aspects of the physical and instrumental measurement had to be investigated to arrive at a system capable of quantitative evaluation of trace concentrations in stope face ore samples. The parameters of spectrum evaluation were investigated from fundamental principles to allow quantitative assessment of different methods of peak evaluation for optimization of the method as a whole. The basic concepts of random signal processing times were developed together with new concepts of pileup parameters to allow a quantitative description of the data acquisition rate of a complete analog pulse processing system. With this foundation a practical measuring geometry and optimum values for signal processing time parameters, for detector size and for discriminator positions for spectrum evaluation could be determined. Parallel with the derivation of optimum measurement parameters went the development of instruments, their field testing and appraisal of the method. The development of the gamma ray fluorescence method has shown the potential of the method to serve as an ore valuation tool and to assist in the geological identification of strata in Witwatersrand gold mines

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-11-01

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

  5. Gamma Spectrometry Analysis of Different Brands of Cement used in Nigeria

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  6. Alpha and gamma spectrometry for natural radioactive nuclides around uranium mines and nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, A.M.; Tome, F.V.; Bejarano, J.D.; Aparicio, A.G. (Universidad de Extremadura, Badajoz (Spain). Dept. de Fisica)

    1992-01-01

    Concentration of uranium and [sup 234]U/[sup 238]U and [sup 235]U/[sup 238]U activity ratios were studied in water samples taken in the neighbourhood of two uranium mines ('El Lobo' and 'El Pedregal', Badajoz, Spain), and around two nuclear power plants and their cooling reservoirs (the Central Nuclear de Almaraz, which is working today, and the Central Nuclear de Valdecaballeros, which is in the construction phase), using alpha spectrometry with semiconductor detectors. The Valdecaballeros data were taken to check for comparison with those of the Central Nuclear de Almaraz and with future values after the start of operation. Measurements were also made of all soluble gamma emitting nuclides using a shielded coaxial high purity germanium detector. The data suggest that the mechanisms responsible for the changes in the concentrations and in the [sup 234]U/[sup 238]U activity ratios in surface waters are principally dilution and leaching. (author).

  7. Study of principle error sources in gamma spectrometry. Application to cross sections measurement

    International Nuclear Information System (INIS)

    Majah, M. Ibn.

    1985-01-01

    The principle error sources in gamma spectrometry have been studied in purpose to measure cross sections with great precision. Three error sources have been studied: dead time and pile up which depend on counting rate, and coincidence effect that depends on the disintegration scheme of the radionuclide in question. A constant frequency pulse generator has been used to correct the counting loss due to dead time and pile up in cases of long and short disintegration periods. The loss due to coincidence effect can reach 25% and over, depending on the disintegration scheme and on the distance source-detector. After establishing the correction formula and verifying its validity for four examples: iron 56, scandium 48, antimony 120 and gold 196 m, an application has been done by measuring cross sections of nuclear reactions that lead to long disintegration periods which need short distance source-detector counting and thus correcting the loss due to dead time effect, pile up and coincidence effect. 16 refs., 45 figs., 25 tabs. (author)

  8. Calibration of a Gamma Spectrometry System Used for the Determination of Cs-137 in Spanish Soils

    International Nuclear Information System (INIS)

    Barreraa, M.; Romero, M. L.; Valino, F.

    2008-01-01

    The document describes the methodology used at CIEMAT in order to determine, by gamma spectrometry, the background levels of the radionuclide Cs-137 in soils of the Spanish peninsular territory. the work is a part of an extensive research project developed jointly by the University of the Basque Country (UPV-EHU) and the CIEMAT, endellite Content and migration of radiocaesium and radiostrontium in Spanish soils, which is funded by the Plan I+D of the Spanish Nuclear Security Council (CSN). The objective of the project is to establish the reference levels of man-made radionuclides in Spanish soils, with respect to which the evaluation of a possible posterior accidental release of radioactive material could be appraised. The activity concentration of the fission products Cs-137 has been determined in 34 soil cores extracted from representative Spanish soils type zones. This publication describes the experimental system employed, its calibration, the particular conditions applied to perform the measurements, as well as the experimental validation of the methodology. The activity profiles and inventories of the radioactive element so obtained are also presented. The estimation of the background Cs-137 reference levels, will provide a basis for later applications as the study of the spatial distribution in the region, the determination of the correlation between the deposited activity and the meteorological conditions, or the calculation of the specific migration parameters of the radioactive elements in Mediterranean conditions. (Author) 15 refs

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

    International Nuclear Information System (INIS)

    Samsahl, K.; Soeremark, R.

    1961-12-01

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

  10. Determination of tellurium by hydride generation with in situ trapping flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Matusiewicz, H.; Krawczyk, M. [Politechn Poznanska, Poznan (Poland)

    2007-03-15

    The analytical performance of coupled hydride generation - integrated atom trap (HG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system was evaluated for determination of Te in reference material (GBW 07302 Stream Sediment), coal fly ash and garlic. Tellurium, using formation of H{sub 2}Te vapors, is atomized in air-acetylene flame-heated IAT. A new design HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangernents (a water-cooled single silica tube, double-slotted quartz tube or an 'integrated trap') was investigated. An improvement in detection limit was achieved compared with using either of the above atom trapping techniques separately. The concentration detection limit, defined as 3 times the blank standard deviation (3{sigma}), was 0.9 ng mL{sup -1} for Te. For a 2 min in situ preconcentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, was 222 fold, using the hydride generation atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed as RSD, was 7.0% (n = 6) for Te. The accuracy of the method was verified using a certified reference material (GBW 07302 Stream Sediment) by aqueous standard calibration curves. The measured Te contents of the reference material was in agreement with the information value. The method was successfully applied to the determination of tellurium in coal fly ash and garlic.

  11. A numerical method for the calibration of in situ gamma ray spectroscopy systems.

    Science.gov (United States)

    Dewey, S C; Whetstone, Z D; Kearfott, K J

    2010-05-01

    High purity germanium in situ gamma ray spectroscopy systems are typically calibrated using pre-calculated tables and empirical formulas to estimate the response of a detector to an exponentially distributed source in a soil matrix. Although this method is effective, it has estimated uncertainties of 10-15%, is limited to only a restricted set of measurement scenarios, and the approach only applies to an exponentially distributed source. In addition, the only soil parameters that can be varied are density and moisture content, while soil attenuation properties are fixed. This paper presents a more flexible method for performing such calibrations. For this new method, a three- or four-dimensional analytical expression is derived that is a combination of a theoretical equation and experimentally measured data. Numerical methods are used to integrate this expression, which approximates the response of a detector to a large variety of source distributions within any soil, concrete, or other matrix. The calculation method is flexible enough to allow for the variation of multiple parameters, including media attenuation properties and the measurement geometry. The method could easily be adapted to horizontally non-uniform sources as well. Detector responses are calculated analytically and Monte Carlo radiation transport simulations are used to verify the results. Results indicate that the method adds an uncertainty of only approximately 5% to the other uncertainties typically associated with the calibration of a detector system.

  12. 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)

  13. Airborne gamma spectrometry measurements in the context of the exercise ARM02

    International Nuclear Information System (INIS)

    Bucher, B.; Rybach, L.; Schwarz, G.; Baerlocher, C.

    2003-05-01

    The international exercise under the European Union project ECCOMAGS (European Coordination and Calibration of Mobile and Airborne Gamma Spectrometry) stood in the centre of the yearly airborne gamma spectrometry measurement flights which were carried out in the time of 27 -31 May 2002. The exercise was held in Southwest Scotland in the region of Dumfries and Galloway. Unfortunately due to difficulties with flight approvals for military aircrafts data could be taken in the exercise area only on the flight back to Switzerland. Immediately after returning to Switzerland the regular measurements around the nuclear power plants Beznau (KKB) and Leibstadt (KKL), around the intermediate storage facilities for radioactive waste (ZWILAG) and around the research facility Paul Scherrer Institute were performed. The flights took place in the context of the exercise ARM02 and were lead by the Swiss National Emergency Operations Centre (NAZ). Unfortunately just a few measurements in the common intercalibration areas could be taken on the flight back from the international exercise. Nevertheless comparisons of the results with those of other European teams could be made. These comparisons proved the good calibration of our equipment. On the flight back measurements were also carried out at great altitude above the sea. This data allowed to determine very well the background of the aircraft and the cosmic stripping ratios. In the context of the regular measurements in the environs of the nuclear facilities in Switzerland the areas around the nuclear power plants Beznau and Leibstadt and around the nuclear research facility Paul Scherrer Institute were measured. The results were very similar to the results of earlier measurements in the last years. The nuclear power plant Beznau couldn't be recognised on the activity maps. But the nuclear power plant Leibstadt could be identified by its direct radiation which is specific for this type of reactor (BWR). At the site of the Paul

  14. 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

  15. Committed effective dose determination in cereal flours by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Scheibel, Viviane

    2006-01-01

    The health impact from radionuclides ingestion of foodstuffs was evaluated by the committed effective doses determined in commercial samples of South-Brazilian cereal flours (soy, wheat, corn, manioc, rye, oat, barley and rice flour). The radioactivity traces of 228 Th, 228 Ra, 226 Ra, 40 K, 7 Be and 137 Cs were measured by gamma-ray spectrometry employing a 66% relative efficiency HPGe detector. The energy resolution for the 1332.46 keV line of 60 Co was 2.03 keV. The committed effective doses were calculated with the activities analyzed in the present flour samples, the foodstuff rates of consumption (Brazilian Institute of Geography and Statistics) and the ingestion dose coefficients (International Commission of Radiological Protection). The reliability median activities were verified with χ 2 tests, assuring the fittings quality. The highest concentration levels of 228 Th and 40 K were 3.5 ± 0.4 and 1469 ± 17 Bq.kg -1 for soy flour, respectively, with 95% of confidence level. The lower limit of detection for 137 Cs ranged from 0.04 to 0.4 Bq.kg -1 . The highest committed effective dose was 0.36 μSv.y -1 for 228 Ra in manioc flour (adults). All committed effective doses determined at the present work were lower than the UNSCEAR limits of 140 μSv.y -1 and much lower than the ICRP (1991) limits of 1 mSv.y -1 , for general public. There are few literature references for natural and artificial radionuclides in foodstuffs and mainly for committed effective doses. This work brings the barley flour data, which is not present at the literature and 7 Be data which is not encountered in foodstuffs at the literature, besides all the other flours data information about activities and committed effective doses. (author)

  16. Comparison of analytical methods used to determine 235U, 238U and 210Pb from sediment samples by alpha, beta and gamma spectrometry

    International Nuclear Information System (INIS)

    Vesterbacka, P.; Klemola, S.; Salahel-Din, K.

    2009-01-01

    An intercomparison of the methodology (alpha, beta and gamma spectrometry) used for 238 U, 235 U and 210 Pb determination was carried out based on 38 sediment samples. The activity range of the samples varied from 10-700 Bq/kg for 210 Pb, 1-35 Bq/kg for 235 U and 10-800 Bq/ kg for 238 U. Results obtained using the three methods were not statistically different at high activity levels, but agreement between the results decreased at lower sample activity levels. For 210 Pb, the smallest difference was found between alpha and gamma spectrometry. A good correlation between results from alpha and gamma spectrometry was observed over the whole activity range. In beta spectrometry, the results were slightly higher than those obtained by alpha or gamma spectrometry due to the impurity of 228 Ra. In 238 U analysis, good correspondence was observed between 238 U determined by gamma and alpha spectrometry, particularly at higher 238 U activity concentrations over 100 Bq/kg. In 235 U analysis, attention needs to be paid to interference from 226 Ra and its reduction. (author)

  17. 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.

  18. 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.

  19. 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)

  20. 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

  1. Production and characterization of a traceable NORM material and its use in proficiency testing of gamma-ray spectrometry laboratories.

    Science.gov (United States)

    Wiedner, H; Riedl, J; Maringer, F J; Baumgartner, A; Stietka, M; Kabrt, F

    2018-04-01

    This paper outlines the process of characterizing a new NORM material for proficiency testing made of quartz sand with significantly elevated levels of 226 Ra obtained from the backflush of a drinking water treatment facility. Samples of the fully characterized NORM material were sent to European laboratories concerned with radioactivity measurements and environmental monitoring by gamma-ray spectrometry for proficiency testing. The paper discusses the results, specific requirements, problems and solutions that were found during the characterization process and the proficiency test. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. The energy calibration and precision of a gamma spectrometry unit - Method using the electron annihilation energy as the only standard

    International Nuclear Information System (INIS)

    Hoclet, Michel

    1971-06-01

    Spectrometry using Ge(Li) detectors is discussed. The excellent resolution of this type of detector, the mathematical analysis of the spectral lines of the pulses, and the reproducibility of the spectrometer enable highly accurate measurements of the abscises (some 10 -5 ) corresponding to the peaks. A method using the annihilation energy of the electron as the only standard was developed. The method is applied to the measurement of the gamma ray energies of the radioelements: 22 Na, 24 Na, 56 Mn, 56 Co, 59 Fe, 72 Ga, 88 Y, 122 Sb, 124 Sb and 137 Cs. (author) [fr

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  4. Radon fixation for determination of {sup 224}Ra, {sup 226}Ra and {sup 228}Ra via gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, M. [Departamento Ingenieria Nuclear y Mecanica de Fluidos, E. S. Ingenieros de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n, 48013 Bilbao (Spain)]. E-mail: inphesom@bi.ehu.es; Idoeta, R. [Departamento Ingenieria Nuclear y Mecanica de Fluidos, E. S. Ingenieros de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n, 48013 Bilbao (Spain); Abelairas, A. [Departamento Ingenieria Nuclear y Mecanica de Fluidos, E. S. Ingenieros de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n, 48013 Bilbao (Spain); Legarda, F. [Departamento Ingenieria Nuclear y Mecanica de Fluidos, E. S. Ingenieros de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n, 48013 Bilbao (Spain)

    2006-04-15

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

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

    Science.gov (United States)

    Reading, David G; Croudace, Ian W; Warwick, Phillip E; Britton, Richard

    2015-11-05

    A rapid and effective preparative procedure has been evaluated for the accurate determination of low-energy (40-200 keV) gamma-emitting radionuclides ((210)Pb, (234)Th, (226)Ra, (235)U) in uranium ores and uranium ore concentrates (UOCs) using high-resolution gamma ray spectrometry. The measurement of low-energy gamma photons is complicated in heterogeneous samples containing high-density mineral phases and in such situations activity concentrations will be underestimated. This is because attenuation corrections, calculated based on sample mean density, do not properly correct where dense grains are dispersed within a less dense matrix (analogous to a nugget effect). The current method overcomes these problems using a lithium tetraborate fusion that readily dissolves all components including high-density, self-attenuating minerals/compounds. This is the ideal method for dissolving complex, non-volatile components in soils, rocks, mineral concentrates, and other materials where density reduction is required. Lithium borate fusion avoids the need for theoretical efficiency corrections or measurement of matrix matched calibration standards. The resulting homogeneous quenched glass produced can be quickly dissolved in nitric acid producing low-density solutions that can be counted by gamma spectrometry. The effectiveness of the technique is demonstrated using uranium-bearing Certified Reference Materials and provides accurate activity concentration determinations compared to the underestimated activity concentrations derived from direct measurements of a bulk sample. The procedure offers an effective solution for initial nuclear forensic studies where complex refractory minerals or matrices exist. It is also significantly faster, safer and simpler than alternative approaches. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Statistical signal processing for gamma spectrometry: application for a pileup correction method

    International Nuclear Information System (INIS)

    Trigano, T.

    2005-12-01

    The main objective of gamma spectrometry is to characterize the radioactive elements of an unknown source by studying the energy of the emitted photons. When a photon interacts with a detector, its energy is converted into an electrical pulse. The histogram obtained by collecting the energies can be used to identify radioactive elements and measure their activity. However, at high counting rates, perturbations which are due to the stochastic aspect of the temporal signal can cripple the identification of the radioactive elements. More specifically, since the detector has a finite resolution, close arrival times of photons which can be modeled as an homogeneous Poisson process cause pile-ups of individual pulses. This phenomenon distorts energy spectra by introducing multiple fake spikes and prolonging artificially the Compton continuum, which can mask spikes of low intensity. The objective of this thesis is to correct the distortion caused by the pile-up phenomenon in the energy spectra. Since the shape of photonic pulses depends on many physical parameters, we consider this problem in a nonparametric framework. By introducing an adapted model based on two marked point processes, we establish a nonlinear relation between the probability measure associated to the observations and the probability density function we wish to estimate. This relation is derived both for continuous and for discrete time signals, and therefore can be used on a large set of detectors and from an analog or digital point of view. It also provides a framework to this problem, which can be considered as a problem of nonlinear density deconvolution and nonparametric density estimation from indirect measurements. Using these considerations, we propose an estimator obtained by direct inversion. We show that this estimator is consistent and almost achieves the usual rate of convergence obtained in classical nonparametric density estimation in the L 2 sense. We have applied our method to a set of

  7. 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.

  8. Comparative determination of uranium in rock phosphates and columbite by ICP-OES, alpha and gamma spectrometry

    International Nuclear Information System (INIS)

    Singhal, R.K.; Sharma, P.K.; Bassan, M.K.T.; Basu, H.; Reddy, A.V.R.

    2011-01-01

    During this work selective separation of uranium from rock phosphate and columbite mineral was done before its quantitative estimation by using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Uranium from the rock phosphate and columbite was extracted by sodium peroxide fusion followed by leaching in 2 M HNO 3 . To avoid spectral interference in the estimation of uranium by ICP-OES, the selective separation of uranium from the leachate was carried out by using two different extractants, 30% Tributyl Phosphates (TBP) in CCl 4 and a equi-volume mixture of Di(2-ethylhexyl) phosphoric acid (D2EHPA) and TBP in petrofin. Uranium was stripped from the organic phase by using 1 M ammonium carbonate solution. Determination of uranium by ICP-OES was done after dissolving the residue left after evaporation of ammonium carbonate solution in 4% HNO 3 . The concentration of the uranium observed in the rock phosphates samples was 40-200 μg g -1 whereas in columbite samples the concentration range was 100-600 μg g -1 . Uranium concentration evaluated by ICP-OES was complimented by gamma and alpha spectrometry. Concentration of uranium evaluated by gamma spectrometry in case of rock phosphate and columbite was in close agreement with the uranium content obtained by ICP-OES. Uranium determination by alpha spectrometry showed only minor deviation (1-2%) from the results obtained by ICP-OES in case of rock phosphates whereas in case of columbites results are off by 20-30%. (author)

  9. Automatic device for {gamma}-spectrometry in EOLE and Minerve facilities; Dispositif automatique de spectrometrie {gamma} des reacteurs EOLE et Minerve

    Energy Technology Data Exchange (ETDEWEB)

    Laval, V.; Philibert, H. [CEA Cadarache, Dept. d' Etudes des Reacteurs (DER/SPEx/LPE), 13 - Saint-Paul-lez-Durance (France)

    2003-07-01

    Experimental programmes ongoing on EOLE and MINERVE critical facilities of the CEA Experimental Physics Service (SPEx) in Cadarache require fission rate measurements by either integral gamma scanning or particular peak check directly on the irradiated fuel pins. These measurements enables to determine radial and axial fission rate distributions as capture rates of specific isotopes in particular core configurations. Up to now, all the fuel handling were performed manually. The development of a new measurement device, called 'automatic bench' was necessary. The project has been launched in 1999 and delivered in 2001. It is in keeping with the frame of experimental uncertainties, dosimetry, safety and security improvements. (authors)

  10. In-situ Isotopic Analysis at Nanoscale using Parallel Ion Electron Spectrometry: A Powerful New Paradigm for Correlative Microscopy

    Science.gov (United States)

    Yedra, Lluís; Eswara, Santhana; Dowsett, David; Wirtz, Tom

    2016-01-01

    Isotopic analysis is of paramount importance across the entire gamut of scientific research. To advance the frontiers of knowledge, a technique for nanoscale isotopic analysis is indispensable. Secondary Ion Mass Spectrometry (SIMS) is a well-established technique for analyzing isotopes, but its spatial-resolution is fundamentally limited. Transmission Electron Microscopy (TEM) is a well-known method for high-resolution imaging down to the atomic scale. However, isotopic analysis in TEM is not possible. Here, we introduce a powerful new paradigm for in-situ correlative microscopy called the Parallel Ion Electron Spectrometry by synergizing SIMS with TEM. We demonstrate this technique by distinguishing lithium carbonate nanoparticles according to the isotopic label of lithium, viz. 6Li and 7Li and imaging them at high-resolution by TEM, adding a new dimension to correlative microscopy. PMID:27350565

  11. In situ mass spectrometry imaging and ex vivo characterization of renal crystalline deposits induced in multiple preclinical drug toxicology studies.

    Directory of Open Access Journals (Sweden)

    Anna Nilsson

    Full Text Available Drug toxicity observed in animal studies during drug development accounts for the discontinuation of many drug candidates, with the kidney being a major site of tissue damage. Extensive investigations are often required to reveal the mechanisms underlying such toxicological events and in the case of crystalline deposits the chemical composition can be problematic to determine. In the present study, we have used mass spectrometry imaging combined with a set of advanced analytical techniques to characterize such crystalline deposits in situ. Two potential microsomal prostaglandin E synthase 1 inhibitors, with similar chemical structure, were administered to rats over a seven day period. This resulted in kidney damage with marked tubular degeneration/regeneration and crystal deposits within the tissue that was detected by histopathology. Results from direct tissue section analysis by matrix-assisted laser desorption ionization mass spectrometry imaging were combined with data obtained following manual crystal dissection analyzed by liquid chromatography mass spectrometry and nuclear magnetic resonance spectroscopy. The chemical composition of the crystal deposits was successfully identified as a common metabolite, bisulphonamide, of the two drug candidates. In addition, an un-targeted analysis revealed molecular changes in the kidney that were specifically associated with the area of the tissue defined as pathologically damaged. In the presented study, we show the usefulness of combining mass spectrometry imaging with an array of powerful analytical tools to solve complex toxicological problems occurring during drug development.

  12. A subfertile patient diagnosed with testicular carcinoma in situ by immunocytological staining for AP-2gamma in semen samples

    DEFF Research Database (Denmark)

    Hoei-Hansen, C E; Rajpert-De Meyts, E; Carlsen, E

    2005-01-01

    The incidence of testicular cancer is rising. Despite a high cure rate, efforts should be made to obtain diagnosis at the pre-invasive intratubular carcinoma in situ (CIS) stage, as the disease is potentially lethal and treatment has severe side-effects, especially regarding reproductive function...... patients, including patients with testicular cancer and subfertility. Cells positive for AP-2gamma were found only in semen samples from patients diagnosed a priori with testicular neoplasms and, surprisingly, in a 23 year old control subject with oligozoospermia and no symptoms of a germ cell tumour...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-07-20

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

  14. Literature survey of chemical analysis by thermal neutron induced capture gamma ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gladney, E.S.

    1979-09-01

    A brief discussion of the principles and techniques of chemical analysis by neutron capture gamma radiation is presented, and the widely scattered literature is collected into a single table arranged by element measured.

  15. Literature survey of chemical analysis by thermal neutron induced capture gamma ray spectrometry

    International Nuclear Information System (INIS)

    Gladney, E.S.

    1979-09-01

    A brief discussion of the principles and techniques of chemical analysis by neutron capture gamma radiation is presented, and the widely scattered literature is collected into a single table arranged by element measured

  16. A prototype of radioactive waste drum monitor by non-destructive assays using gamma spectrometry

    International Nuclear Information System (INIS)

    Thanh, Tran Thien; Trang, Hoang Thi Kieu; Chuong, Huynh Dinh; Nguyen, Vo Hoang; Tran, Le Bao; Tam, Hoang Duc; Tao, Chau Van

    2016-01-01

    In this work, segmented gamma scanning and the gamma emission tomography were used to locate unknown sources in a radioactive waste drum. The simulated detector response function and full energy peak efficiency are compared to corresponding experimental data and show about 5.3% difference for an energy ranging from 81 keV to 1332.5 keV for point sources. Computation of the corresponding activity is in good agreement with the true values. - Highlights: • Segmented gamma scanning and gamma emission tomography are used to locate point source in waste drums. • The PENELOPE software is used to compute the detection efficiency of the localized point source in the waste drum. • The activity of 137 Cs and 60 Co point source could be determined with an accuracy better than 10% for air and sand matrices.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-06-01

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

  18. Application of Monte Carlo techniques for standardless efficiency calibration of NaI(Tl) based gamma spectrometry system

    International Nuclear Information System (INIS)

    Verma, Amit K.; Anilkumar, S.; Narayani, K.; Babu, D.A.R.; Sharma, D.N.

    2012-01-01

    The gamma ray spectrometry technique is commonly used for the assessment of radioactivity in environmental matrices like water, soil, vegetation etc. The detector system used for gamma ray spectrometer should be calibrated for each geometry considered and for different gamma energies. It is very difficult to have radionuclide standards to cover all photon energies and also not feasible to make standard geometries for common applications. So there is a need to develop some computational techniques to determine absolute efficiencies of these detectors for practical geometries and for energies of common radioactive sources. A Monte Carlo based simulation method is proposed to study the response of the detector for various energies and geometries. From the simulated spectrum it is possible to calculate the efficiency of the gamma energy for the particular geometry modeled. The efficiency calculated by this method has to be validated experimentally using standard sources in laboratory conditions for selected geometries. For the present work simulation studies were under taken for the 3″ x 3″ NaI(Tl) detector based gamma spectrometry system set up in our laboratory. In order to see the effectiveness of the method for the low level radioactivity measurement it is planned to use low active standard source of 40 K in cylindrical container geometry for our work. Suitable detector and geometry model was developed using KCI standard of the same size, composition, density and radionuclide contents. Simulation data generated was compared with the experimental spectral data taken for a counting period of 20000 sec and 50000 sec. The peak areas obtained from the simulated spectra were compared with that of experimental spectral data. It was observed that the count rate (9.03 cps) in the simulated peak area is in agreement with that of the experimental peak area count rates (8.44 cps and 8.4 cps). The efficiency of the detector calculated by this method offers an alternative

  19. Development of an open source software of quantitative analysis for radionuclide determination by gamma-ray spectrometry using semiconductor detectors

    International Nuclear Information System (INIS)

    Maduar, Marcelo Francis

    2010-01-01

    Radioactivity quantification of gamma-ray emitter radionuclides in samples measured by HPGe gamma-ray spectrometry relies on the analysis of the photopeaks present in the spectra, especially on the accurate determination of their net areas. Such a task is usually performed with the aid of proprietary software tools. This work presents a methodology, algorithm descriptions and an open source application, called OpenGamma, for the peak search and analysis in order to obtain the relevant peaks parameters and radionuclides activities. The computational implementation is released entirely in open-source license for the main code and with the use of open software packages for interface design and mathematical libraries. The procedure for the peak search is performed on a three step approach. Firstly a preliminary search is done by using the second-difference method, consisting in the generation of a derived spectrum in order to find candidate peaks. In the second step, the experimental peaks widths are assessed and well formed and isolated ones are chosen to obtain a FWHM vs. channel relationship, by application of the Levenberg-Marquardt minimization method for non-linear fitting. Lastly, regions of the spectrum with grouped peaks are marked and a non-linear fit is again applied to each region to obtain baseline and photopeaks terms; from these terms, peaks net areas are then assessed. (author)

  20. A broadband gamma-ray spectrometry using novel unfolding algorithms for characterization of laser wakefield-generated betatron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Jong Ho, E-mail: jhjeon07@ibs.re.kr; Nakajima, Kazuhisa, E-mail: naka115@dia-net.ne.jp; Pathak, Vishwa Bandhu; Cho, Myung Hoon; Yoo, Byung Ju; Shin, Kang Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Kim, Hyung Taek; Sung, Jae Hee; Lee, Seung Ku; Choi, Il Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Rhee, Yong Joo [Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Shin, Jung Hun; Jo, Sung Ha [Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Hojbota, Calin; Cho, Byeoung Ick; Nam, Chang Hee [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 500-712 (Korea, Republic of)

    2015-12-15

    We present a high-flux, broadband gamma-ray spectrometry capable of characterizing the betatron radiation spectrum over the photon energy range from 10 keV to 20 MeV with respect to the peak photon energy, spectral bandwidth, and unique discrimination from background radiations, using a differential filtering spectrometer and the unfolding procedure based on the Monte Carlo code GEANT4. These properties are experimentally verified by measuring betatron radiation from a cm-scale laser wakefield accelerator (LWFA) driven by a 1-PW laser, using a differential filtering spectrometer consisting of a 15-filter and image plate stack. The gamma-ray spectra were derived by unfolding the photostimulated luminescence (PSL) values recorded on the image plates, using the spectrometer response matrix modeled with the Monte Carlo code GEANT4. The accuracy of unfolded betatron radiation spectra was assessed by unfolding the test PSL data simulated with GEANT4, showing an ambiguity of less than 20% and clear discrimination from the background radiation with less than 10%. The spectral analysis of betatron radiation from laser wakefield-accelerated electron beams with energies up to 3 GeV revealed radiation spectra characterized by synchrotron radiation with the critical photon energy up to 7 MeV. The gamma-ray spectrometer and unfolding method presented here facilitate an in-depth understanding of betatron radiation from LWFA process and a novel radiation source of high-quality photon beams in the MeV regime.

  1. Mapping of radiation anomalies using UAV mini-airborne gamma-ray spectrometry.

    Science.gov (United States)

    Šálek, Ondřej; Matolín, Milan; Gryc, Lubomír

    2018-02-01

    Localization of size-limited gamma-ray anomalies plays a fundamental role in uranium prospecting and environmental studies. Possibilities of a newly developed mini-airborne gamma-ray spectrometric equipment were tested on a uranium anomaly near the village of Třebsko, Czech Republic. The measurement equipment was based on a scintillation gamma-ray spectrometer specially developed for unmanned aerial vehicles (UAV) mounted on powerful hexacopter. The gamma-ray spectrometer has two 103 cm 3 BGO scintillation detectors of relatively high sensitivity. The tested anomaly, which is 80 m by 40 m in size, was investigated by ground gamma-ray spectrometric measurement in a detail rectangular measurement grid. Average uranium concentration is 25 mg/kg eU attaining 700 mg/kg eU locally. The mini-airborne measurement across the anomaly was carried out on three 100 m long parallel profiles at eight flight altitudes from 5 to 40 m above the ground. The resulting 1 s 1024 channel gamma-ray spectra, recorded in counts per second (cps), were processed to concentration units of K, U and Th, while total count (TC) was reported in cps. Increased gamma ray intensity of the anomaly was indicated by mini-airborne measurement at all profiles and altitudes, including the highest altitude of 40 m, at which the recorded intensity is close to the natural radiation background. The reported instrument is able to record data with comparable quality as standard airborne survey, due to relative sensitive detector, lower flight altitude and relatively low flight speed of 1 m/s. The presented experiment brings new experience with using unmanned semi-autonomous aerial vehicles and the latest mini-airborne radiometric instrument. The experiment has demonstrated the instrument's ability to localize size-limited uranium anomalies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. A novel approach to the determination of iridium via Ge-coincidence/NaI(Tl)-anticoincidence gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Cumming, J.B.

    1988-01-01

    Iridium has proven to be a useful fingerprint of extraterrestrial material, and neutron activation analysis is the method of choice for its determination because of the high thermal cross section (910 b) of 191 Ir (37.3% natural abundance) and the favorable decay characteristics of the product nuclide. However, radiochemical separations are frequently required for the determination of iridium at low concentrations (in the ppb range). The present work describes a precise, nondestructive neutron-activation procedure that is capable of analyzing samples of both high (ppm) and low (ppb) Ir content. Advantage is taken of the fact that the principal gamma lines of 73.8-d 192 Ir are in various coincidences with one another. Instead of conventional gamma-gamma coincidence spectrometry with two Ge detectors, we utilize the 784.6- and 920.9- keV sum peaks which are generated when an iridium containing sample is placed in the well of a highly-efficient HPGe detector. The well-type detector is positioned centrally in a large annular NaI(Tl) detector which is operated in an anticoincidence mode. This improves the quality of the gamma spectra by suppressing the Compton backgrounds due to nuclides such as 60 Co by a factor of 4-6 in the regions of interest without affecting the intensities of the two sum peaks. The sensitivity of this method under our experimental conditions (20-mg sample irradiated at 1.5x10 14 n cm -2 s -1 for 5 min and counted 3-4 weeks after irradiation) is ≅ 5 ppb Ir in a relatively unfavorable matrix such as peridotite. (orig.)

  3. Development of high sensitivity gamma and beta sensors for in situ diffusion tests in the mudstone in France

    International Nuclear Information System (INIS)

    Lin, Zhenhua

    2017-01-01

    The precise monitoring of radiotracers, for example used for medical imaging, for the storage of ultimate waste, or for certain industrial applications can be a very complex subject. The development of low-noise sensors with long-term stability and high geometric flexibility were engaged by the AXINT company. (Hautefeuille, et al., 2006). My PhD thesis was focused on experiments in the diffusion of radiotracers, typically to monitor the possible leakage of radioactive products from the geological repositories. We focuses on the study of the 22 Na and 36 Cl ion diffusion, which is one of the highest cation and anions diffusion rate in geological medium, as well as actinides, which represent the majority of the radioactive elements of Stored nuclear waste. This thesis is in continuity with the research carried out by ANDRA (National Agency for Radioactive Waste), under contract with the laboratory ILM (Institute Light Matter), of which AXINT is the main subcontractor. The present project describes the research work that foreseen the radiation impact on the environment for the coming years during the deep disposal of nuclear waste. Our work focus on the investigation and quantification of the radionuclide diffusion through the geological clay barriers. A new in situ experiment was considered by Andra for the study of the radionuclide migration. Compared to previous experiments, this new in situ diffusion test required longer distance (hundreds of mm), longer time-scale (over 10 years), and real time in situ monitoring of radionuclides migration. To fulfill these conditions, the work was organized as following: 1: Conception and dimensional design of the Diffusion of Radio Nuclide (DRN) experiments in solving emission of beta and gamma radiations 2: Development of corresponding beta and gamma monitoring systems by means of sensors located in peripheral boreholes. (author) [fr

  4. 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

  5. Beta, gamma contamination analysis of thermo luminescence dosimeter cassettes using Geiger Muller counting set up and gamma spectrometry techniques

    International Nuclear Information System (INIS)

    Prasad, S.K.; Sudheer, T.S.; Sahoo, L.; Vinayagam, Bhakti; Kamble, Mahesh; Khuspe, R.R.; Anilkumar, Rekha; Verma, K.K.

    2009-01-01

    Β-γ contamination cheek up of TLD cassettes were carried out and the isotopes found were 137 Cs, 106 Ru, 60 Co, 64 Cu, 144 Ce and 95 Nb with activity per square cm varying from 0.05-4.70 Bq/cm 2 with median value 1.3. The assessed dose in TLD was in the range of 2.10 mSv to 22.05 mSv for beta, 0.05 mSv to 5.25 mSv for gamma. The beta doses have median value of 6.19 mSv. This contamination may be due to active water contamination on TLD's of personnel working for irradiated fuel handling or work in fuel rod (under water) storage area. This gives a method to estimate skin exposure of personnel due to skin contamination during work. Chances of getting TLD's contaminated due to various reasons were studied. Contamination was found maximum inside the cassette box having area 16 cm 2 . In case of plastic pouch of TLD disc contamination was detected in three cases. Contamination level on TLD cassettes using GM counter was found in the range of 0.30-3.6 Bq/cm 2 for cassettes. By opening the window of the surveymeter contamination and field of these cassettes in closed condition were found to increase by 20% due to the measurement of beta dose. With the same condition contamination of TLD cassette in open condition was found five times more. This is due to the a-contamination which is five times more than a contamination, The most prominent isotope 137 Cs in common chemical forms are soluble in water and if inhaled or ingested are rapidly and completely absorbed in the lungs and across the gastrointestinal tract. Thus a skin contamination of most prominent isotope 137 Cs can lead to intake in addition to skin dose. Fading studies of contamination of TLD cassettes were carried out. It was found negligible after counting with GM counting set up after a period of 3 months. But one of the TLD cassettes was showing an 80% reduction of contamination after 3 months with GM counting set up, the contaminants being 141 Ce, 103 Ru and 95 Nb. The gamma peaks in the external exposure

  6. Comparison of in situ gamma soil analysis and soil sampling data for mapping 241Am and 239Pu soil concentrations at the Nevada Test Site

    International Nuclear Information System (INIS)

    Kirby, J.A.; Anspaugh, L.R.; Phelps, P.L.; Huckabay, G.W.; Markwell, F.R.; Barnes, M.G.

    1977-01-01

    Soil sampling and in situ 241 Am-gamma counting with an array of four high-purity, planar, Ge detectors are compared as means of determining soil concentration contours of plutonium and their associated uncertainties. Results of this survey, which covered an area of approximately 300,000 m 2 , indicate that with one-third the number of sampling locations, the in situ gamma survey provided soil concentration contours with confidence intervals that were about one-third as wide as those obtained with soil sampling. The methods of the survey are described and a discussion of advantages and limitations of both methods is given

  7. Determination of protein content in seeds by prompt gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Carbonari, A.W.; Pecequilo, B.R.S.

    1984-01-01

    The protein level in seeds can be directly calculated through the determination of the nitrogen content in grains. The authors show here that the radioactive thermal neutron capture prompt gamma-rays technique can be used to determine the nitrogen content in grains without chemical destruction, with good precision and relative rapidity, by detecting the prompt gamma rays emitted by the 14 N(n,γ) 15 N reaction product. The samples were irradiated in the tangential tube of the IEA-R1 research reactor, in Sao Paulo, and a pair spectrometer was used for the detection of the prompt gamma-rays. The nitrogen content was determined in several samples of soybean, common bean, peas and rice and the results compared with typical nitrogen content values for each grain. 33 references, 1 figure, 1 table

  8. Burn-Up Determination by High Resolution Gamma Spectrometry: Axial and Diametral Scanning Experiments

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-02-15

    In the gamma spectrometric determination of burn-up the use of a single fission product as a monitor of the specimen fission rate is subject to errors caused by activity saturation or, in certain cases, fission product migration. Results are presented of experiments in which all the resolvable gamma peaks in the fission product spectrum have been used to calculate the fission rate; these results form a pattern which reflect errors in the literature values of the gamma branching ratios, fission yields etc., and also represent a series of empirical correction factors. Axial and diametral scanning experiments on a long-irradiated low-enrichment fuel element are also described and demonstrate that it is possible to differentiate between fissions in U-235 and in Pu-239 respectively by means of the ratios of the Ru-106 activity to the activities of the other fission products.

  9. High resolution gamma-ray spectrometry of culverts containing transuranic waste at the Savannah River Site

    International Nuclear Information System (INIS)

    Hofstetter, K.J.; Sigg, R.

    1990-01-01

    A number of concrete culverts used to retrievably store drummed, dry, radioactive waste at the Savannah River Site (SRS), were suspected of containing ambiguous quantities of transuranic (TRU) nuclides. These culverts were assayed in place for Pu-239 content using thermal and fast neutron counting techniques. High resolution gamma-ray spectroscopy on 17 culverts, having neutron emission rates several times higher than expected, showed characteristic gamma-ray signatures of neutron emitters other than Pu-239 (e.g., Pu-238, Pu/Be, or Am/Be neutron sources). This study confirmed the Pu-239 content of the culverts with anomalous neutron rates and established limits on the Pu-239 mass in each of the 17 suspect culverts by in-field, non-intrusive gamma-ray measurements

  10. Studies on the true coincidence correction in measuring filter samples by gamma spectrometry

    CERN Document Server

    Lian Qi; Chang Yong Fu; Xia Bing

    2002-01-01

    The true coincidence correction in measuring filter samples has been studied by high efficiency HPGe gamma detectors. The true coincidence correction for a specific three excited levels de-excitation case has been analyzed, and the typical analytical expressions of true coincidence correction factors have been given. According to the measured relative efficiency on the detector surface with 8 'single' energy gamma emitters and efficiency of filter samples, the peak and total efficiency surfaces are fitted. The true coincidence correction factors of sup 6 sup 0 Co and sup 1 sup 5 sup 2 Eu calculated by the efficiency surfaces agree well with experimental results

  11. Mathematical model of gamma-ray spectrometry borehole logging for quantitative analysis

    Science.gov (United States)

    Schimschal, Ulrich

    1981-01-01

    A technique for analyzing gamma-ray spectral-logging data has been developed, in which a digital computer is used to calculate the effects of gamma-ray attentuation in a borehole environment. The computer model allows for the calculation of the effects of lithology, porosity, density, and the thickness of a horizontal layer of uniformly distributed radioactive material surrounding a centralized probe in a cylindrical borehole. The computer program also contains parameters for the calculation of the effects of well casing, drilling fluid, probe housing, and losses through the sodium-iodide crystal. Errors associated with the commonly used mathematical assumption of a point detector are eliminated in this model. (USGS)

  12. Identification of early Llandovery (Silurian) anoxic palaeo-depressions at the western margin of the Murzuq Basin (southwest Libya), based on gamma-ray spectrometry in surface exposures

    Czech Academy of Sciences Publication Activity Database

    Fello, N.; Lüning, S.; Štorch, Petr; Redfern, J.

    2006-01-01

    Roč. 11, č. 3 (2006), s. 101-118 ISSN 1025-6059 R&D Projects: GA ČR GA205/99/1322 Institutional research plan: CEZ:AV0Z30130516 Keywords : postglacial anoxy * early Llandovery * Murzuq Basin * palaeo-depressions * gamma-spectrometry Subject RIV: DB - Geology ; Mineralogy

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

    Czech Academy of Sciences Publication Activity Database

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

    2017-01-01

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

  14. System for continuous real time air monitoring by means of gamma spectrometry with germanium dosimeter

    International Nuclear Information System (INIS)

    Montalto, M.; Giacomelli, R.; Nocente, M.; Bortoluzzi, S.; Spezzano, P.

    1990-12-01

    Design of automatic system for real time air monitoring of radioactive particulates are relate. Recommendations are made for design and operation of sampling conduits to minimize losses. By means of experimental equipment loss of particles in long sampling conduits, minimum detectable activity and efficiency of gamma radiation detectable are evaluated. (author)

  15. Gamma spectrometry of irradiated fuel plates; Espectrometria gama em elementos combustiveis tipo placa irradiados

    Energy Technology Data Exchange (ETDEWEB)

    Terremoto, Luis A.A.; Zeituni, Carlos A.; Perrotta, Jose A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Engenharia do Nucleo

    1997-10-01

    This work describes the fundamental aspects of a method which uses gamma-ray spectroscopy in order to perform non-destructive burnup measurements in irradiated MTR fuel elements. Experiments based on such method will be conducted at the storage pool area of the IEA-R1 research reactor. Some preliminary results are presented. (author). 10 refs., 5 figs., 1 tab.

  16. Drill-Core Scanning for Radioelements by Gamma-Ray Spectrometry

    DEFF Research Database (Denmark)

    Løvborg, Leif; Wollenberg, H.; Rose-Hansen, J.

    1972-01-01

    A system has been developed for the continuous and stepwise scanning of rock drill cores for gamma-ray spectrometric determinations of uranium, thorium, and potassium. The apparatus accomodates 3- to 4-cm-diameter core as it passes two opposing 2-inch diameter by 3-inch- thick NaI(Tl) detectors...

  17. Drill-Core Scanning for Radioelements by Gamma-Ray Spectrometry

    DEFF Research Database (Denmark)

    Løvborg, Leif; Wollenberg, H.; Rose-Hansen, J.

    1972-01-01

    A system has been developed for the continuous and stepwise scanning of rock drill cores for gamma-ray spectrometric determinations of uranium, thorium, and potassium. The apparatus accomodates 3- to 4-cm-diameter core as it passes two opposing 2-inch diameter by 3-inch- thick NaI(Tl) detectors, ...

  18. In-situ trapping of bismuthine in externally heated quartz tube atomizers for atomic absorption spectrometry

    Czech Academy of Sciences Publication Activity Database

    Kratzer, Jan; Dědina, Jiří

    2006-01-01

    Roč. 21, č. 2 (2006), s. 208-210 ISSN 0267-9477 R&D Projects: GA AV ČR IAA400310507 Institutional research plan: CEZ:AV0Z40310501 Keywords : bismuth ine preconcentration * quartz surface * hydride generation atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.630, year: 2006

  19. Chemical analysis of radioactive mixed liquid wastes by Alpha/Gamma Spectrometry, ICP-OES and Arsenazo III

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Eduardo G.A.; Ferreira, Rafael V.P.; Araujo, Leandro G.; Dellamano, Jose Claudio; Marumo, Julio T., E-mail: jtmarumo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Taddei, Maria Helena Tirollo, E-mail: mhtaddei@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas

    2013-07-01

    Radioactive waste characterization is a very important step in radioactive waste management because it can influence subsequent stages, as waste conditioning, storage and disposal. This characterization must provide reliable information in order to satisfy some quality requirements based on chemical analysis of representative waste samples. This paper presents procedures adopted for characterization of thirteen different mixed liquid wastes stored at Waste Management Laboratory of Nuclear and Energy Research Institute, IPEN-CNEN/SP. The first action was the sampling of representative samples of each liquid storage package, followed by the alpha and gamma spectrometry, Arsenazo III and ICP-OES analysis. It was identified the radionuclides U, Pu, Cs and Am and others seven chemical elements. The results obtained will be used to perform the treatment of these wastes. (author)

  20. 40 K, 137 Cs and 232 Th activities in Brazilian milk samples measured by gamma ray spectrometry

    International Nuclear Information System (INIS)

    Melquiades, Fabio L.; Appoloni, Carlos R.

    2000-01-01

    This work deals with the measurement of radioactive activities in powdered milk, with high resolution gamma-ray spectrometry, using a HPGe detector coupled to a standard electronic nuclear chain and a multichannel card of 8192 channels. Preliminary measurements were accomplished to define the kind of the system shield, the geometry of the sample recipient, the size of the sampling and the self absorption correction. It was possible to measure the radionuclides 40 K, 137 Cs and 208 Tl, whose activities were calculated according to the International Atomic Energy Agency norms. The detector efficiency was measured employing calibrated samples, prepared with IAEA certificate standards mixed with powdered milk. Tukey's average comparison test was used to check the repeatability of the measurements and the absence of significant systematic deviation. (author)

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

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  2. Application of the radiochemical - and the direct gamma ray spectrometry method to the burnup determination of irradiated uranium oxide

    International Nuclear Information System (INIS)

    Cunha, I.I.L.

    1979-01-01

    The burn up of natural U 3 O 8 that occurs by the action of thermal neutrons was determined, using the radioisotopes 144 Ce, 137 Cs, 103 Ru, 106 Ru and 95 Zr as monitors. The determination of the burn up was made using both destructive and non-destructive methods. In the non-destructive method, the technique of direct gamma-ray spectrometry was used and the radioisotopes mentioned were simultaneously counted in a Ge-Li detector. In the radiochemical method the same radioisotopes were isolated one from the other and from all other fission products before counting. The solvent extraction technique was used for the radiochemical separation of uranium, cerium, cesium and ruthenium. To separate zirconium and niobium, adsorption in silica-gel was used. The extraction agent employed to isolate cesium was dipycrilamine and for the separation of the other radioisotopes Di-(2-Ethyl Hexyl) Phosphoric acid (HDEHP) was used. (Author) [pt

  3. Radiation hazards and lifetime risk assessment of tap water using liquid scintillation counting and high-resolution gamma spectrometry.

    Science.gov (United States)

    Al-Shboul, K F; Alali, A E; Batayneh, I M; Al-Khodire, H Y

    2017-11-01

    In this work, two complementary techniques, viz. liquid scintillation counting and high-resolution gamma spectrometry are utilized to analyze radionuclides concentrations in tap water of Irbid governorate, Jordan, and study their correlation. Gross alpha and gross beta concentrations, in the tap water samples collected from the nine districts of Irbid governorate, ranged from tap water samples, shows that the activity concentrations of 226 Ra, 232 Th, and 40 K ranged between tap water in drilled wells leads to higher levels of radioactivity concentrations beyond the international permissible limits. Furthermore, the average lifetime risk and annual effective dose received by age-grouped inhabitants due to direct and indirect tap water consumption are evaluated, where most of the received dose is attributed to 226 Ra. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Study pf apatite accurrence from Gaviao and Serra de Jacabina gold deposit by scintillometry and gamma spectrometry

    International Nuclear Information System (INIS)

    Barreto, P.T.

    1974-01-01

    This work presents the results of radiogeologic reconnaissance in the Cenozoic, Mesozoic and Pre-Cambrian formations, localized between Salvador and Miguel Calmon, and of the radiogeologic detail study from areas of the radioactive anomalies: Gaviao in the Riacho do Lacuipe and Canavieira Mine, in the Jacobina, Bahia States Scintilometry and gamma spectrometry results make possible to conclude by the association, in the Gaviao's apatite mineralization with throrium and the gold of the Serra de Corrego's conglamerate with uranium, make possible in the both case, orient the Search and the mining by scintilometry. The petrographic study and the radiactivity elements dispersion, suggest a sedimentary primary origin to the regional metamorphic rocks. In the Canavieiras mine was evident the stratigraphic control of the gold, associated to uranium and pirite in the conglomerates. (C.D.G.) [pt

  5. Optimization of a neural network model for signal-to-background prediction in gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Dragovic, S.; Onjia, A. . E-mail address of corresponding author: sdragovic@inep.co.yu; Dragovic, S.)

    2005-01-01

    The artificial neural network (ANN) model was optimized for the prediction of signal-to-background (SBR) ratio as a function of the measurement time in gamma-ray spectrometry. The network parameters: learning rate (α), momentum (μ), number of epochs (E) and number of nodes in hidden layer (N) were optimized simultaneously employing variable-size simplex method. The most accurate model with the root mean square (RMS) error of 0.073 was obtained using ANN with online backpropagation randomized (OBPR) algorithm with α = 0.27, μ 0.36, E = 14800 and N = 9. Most of the predicted and experimental SBR values for the eight radionuclides ( 226 Ra, 214 Bi, 235 U, 40 K, 232 Th, 134 Cs, 137 Cs and 7 Be), studied in this work, reasonably agreed to within 15 %, which was satisfactory accuracy. (author)

  6. Investigating the Origin and Evolution of Venus with In Situ Mass Spectrometry

    Science.gov (United States)

    Trainer, M. G.; Mahaffy, P. R.; Brinckerhoff, W. B.; Johnson, N. M.; Glaze, L. S.

    2015-01-01

    Measurement of noble gas abundances on Venus remain a high priority for planetary science. These studies are only possible through in situ measurement, and can be accomplished by a modern neutral mass spectrometer (NMS) such as that developed at NASA Goddard, based on flight-proven technology. Here we show how the measurement of noble gases can be secured using demonstrated enrichment techniques.

  7. Calibration and application of a HPGe gamma spectrometer for in-situ measurements

    International Nuclear Information System (INIS)

    Xiao Xuefu; Yue Qingyu

    1992-02-01

    The principle and methods of the calibration for an in-situ γ spectrometer are introduced. The calibration for a portable HPGe γ spectrometer has been completed. The N f /A(peak count rate per unit activity in soil) and N f /D(peak count rate per unit absorbed dose rate in the air) are listed. The uncertainties of the calibration factors are estimated. The in-situ measurements have been carried out in surroundings near the nuclear facilities and the data are compared with those measured by other methods

  8. Matrix effects in the determination of phosphorus and sodium by proton-induced prompt gamma spectrometry

    International Nuclear Information System (INIS)

    Olivier, C.; Morland, H.J.

    1990-01-01

    By measuring the yield of prompt gamma rays, induced by accelerated charged particles, the ratio of the ranges in sample and standard can be used in the average cross-section method to determine elemental or isotopic compositions. By spiking the sample with a known amount of a compound containing a non-analyte element (absent in the sample), the appropriate range in the sample can be determined by measuring the prompt gamma rays induced in the non-analyte spike. With lithium compounds as the non-analyte spike, sodium and phosphorus were determined in ivory. The method was tested by analysing the standard reference materials SRM 91, SRM 120c, and SRM 694. 2 figs., 5 tabs., 10 refs

  9. Gamma ray spectrometry logs as a hydrocarbon indicator for clastic reservoir rocks in Egypt.

    Science.gov (United States)

    Al-Alfy, I M; Nabih, M A; Eysa, E A

    2013-03-01

    Petroleum oil is an important source for the energy in the world. The Gulf of Suez, Nile Delta and South Valley are important regions for studying hydrocarbon potential in Egypt. A thorium normalization technique was applied on the sandstone reservoirs in the three regions to determine the hydrocarbon potentialities zones using the three spectrometric radioactive gamma ray-logs (eU, eTh and K% logs). The conventional well logs (gamma-ray, deep resistivity, shallow resistivity, neutron, density and sonic logs) are analyzed to determine the net pay zones in these wells. Indices derived from thorium normalized spectral logs indicate the hydrocarbon zones in petroleum reservoirs. The results of this technique in the three regions (Gulf of Suez, Nile Delta and South Valley) are in agreement with the results of the conventional well log analyses by ratios of 82%, 78% and 71% respectively. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  10. Gamma spectrometry at OSIRIS. Determination of the power and combustion rate of irradiated fuel elements

    International Nuclear Information System (INIS)

    Destot, M.; Musso, J.F.; Cerles, J.M.

    1975-12-01

    An original gamma spectrometer is available at Saclay near the core of the Osiris reactor. With such a device, it is possible to investigate nuclear fuel elements irradiated at Osiris or originating from power reactors. It is quite possible to build devices based on this principle in nuclear power reactors, more particularly in water reactors. With such a device, it is possible to follow the evolution in space and with time of a large number of fission products, and from there to draw precious conclusions relative to reactor safety (e.g. failed element detection) and to fuel economy (i.e. determination of combustion rate). The general characteristics of the device are given as well as its applications: determination of the mass combustion and of the linear power of an irradiated element. A non-destructive, versatile and fast means of investigation is therefore given by the installation of gamma spectroscopy inside a reactor [fr

  11. In-situ γ spectrometry of the Chernobyl fallout using soil-sample independent corrections for surface roughness and migration

    International Nuclear Information System (INIS)

    Karlberg, O.

    1993-12-01

    The 661 keV gamma and 32 keV X-ray fluences from Cs-137 were measured in-situ with a Gamma-X Ge detector on different types of urban and rural surfaces. In comparison with a model calculation, the 661 keV fluence was used to estimate the surface activity assuming an ideal, infinite surface and the quotient between the 32 and 661 fluences was used to estimate the correction factors for the surfaces due to migration and surface roughness. As an alternative to the X-ray method, the use of a collimator for ordinary measurements of the 661 keV peak was analysed, and compared with the X-ray method and with measurements without a collimator. The X-ray method with the optimal soil distribution and composition gives the best results, but ordinary measurements with use of a collimator with a constant correction factor seems to be an appropriate method, when soil profiles for determination of a more exact calibration factor are not available

  12. Fully automated system for Pu measurement by gamma spectrometry of alpha contaminated solid wastes

    International Nuclear Information System (INIS)

    Cresti, P.

    1986-01-01

    A description is given of a fully automated system developed at Comb/Mepis Laboratories which is based on the detection of specific gamma signatures of Pu isotopes for monitoring Pu content in 15-25 l containers of low density (0.1 g/cm 3 ) wastes. The methodological approach is discussed; based on experimental data, an evaluation of the achievable performances (detection limit, precision, accuracy, etc.) is also given

  13. The regime of scintillation counter twin platean in case of direct gamma radiation spectrometry

    International Nuclear Information System (INIS)

    Gulin, Yu.A.; Bernshtejn, D.A.; Trufanova, V.V.; Gajnanshin, A.G.

    1976-01-01

    The investigation is concerned with a spectrometric method of direct gamma irradiation recorded from two sources with different irradiation energies, or from one source with two lines in the spectrum. It has been shown that if lines differ in energy 2-4 times, the indicator count characteristic has two plateaus. This considerably simplifies the separation of lines and the separating installation scheme and improves measurement accuracy

  14. Gamma ray spectrometry logs as a hydrocarbon indicator for clastic reservoir rocks in Egypt

    International Nuclear Information System (INIS)

    Al-Alfy, I.M.; Nabih, M.A.; Eysa, E.A.

    2013-01-01

    Petroleum oil is an important source for the energy in the world. The Gulf of Suez, Nile Delta and South Valley are important regions for studying hydrocarbon potential in Egypt. A thorium normalization technique was applied on the sandstone reservoirs in the three regions to determine the hydrocarbon potentialities zones using the three spectrometric radioactive gamma ray-logs (eU, eTh and K% logs). The conventional well logs (gamma-ray, deep resistivity, shallow resistivity, neutron, density and sonic logs) are analyzed to determine the net pay zones in these wells. Indices derived from thorium normalized spectral logs indicate the hydrocarbon zones in petroleum reservoirs. The results of this technique in the three regions (Gulf of Suez, Nile Delta and South Valley) are in agreement with the results of the conventional well log analyses by ratios of 82%, 78% and 71% respectively. - Highlights: ► The positive DRAD values indicate the hydrocarbon zones in petroleum reservoirs. ► Thorium normalization was applied to determine the hydrocarbon potentialities. ► The conventional well logs are analyzed to determine the net pay zones in wells. ► Determining hydrocarbon potentialities zones using spectrometric gamma-ray logs

  15. Power and combustion rate determination of irradiated nuclear fuels at Osiris by in pile gamma spectrometry

    International Nuclear Information System (INIS)

    Musso, J.F.

    1976-01-01

    The OSIRIS reactor is a particularly well suited tool for the study of the various types of reactors, either in normal operation or under emergency conditions. Among the reference parameters which allow a comparison between irradiation conditions in an experimental and a power reactor, the specific burn-up and the power are of importance. until now, no single method of power and burn up measurement could give simultaneously precise results and fast measurements without destroying the fuel itself. Hence the incentive to make use of in-pile gamma fuel scanning to provide an overall answer to these questions. Chapter 1 reviews the most important experimental methods of determination of the specific burn up and of irradiation power and a summary of the principles of in-pile gamma fuel scanning. Chapter 2 describes the tools, the calculation programs and the experimental apparatus used in this study. Chapter 3 is concerned with the determination of the specific burn up using in-pile gamma fuel scanning. Chapter 4 describes the method of determination of the irradiation power and gives the first experimental results [fr

  16. The study and development of cadmium telluride detectors for gamma ray spectrometry

    International Nuclear Information System (INIS)

    Knispel, Gerard

    1970-01-01

    The purpose of this work is the study of possibility of cadmium telluride's utilisation in gamma ray spectroscopy. This material has some superiorities in comparison with germanium which is utilised in (Ge Li) structures. In a first chapter we study the interaction of rays with matter in the particular case of cadmium telluride. The range of α and β rays in the some way as the effect cross section of gamma ray versus energy are deducted from data tabulated for tin which has a density and an atomic weight very near. The problems related with creation and collection of charges in a cadmium telluride structure are discussed in the same way as the resolution in nuclear spectroscopy, acting the different parameters characterising the detector. In the second chapter, after some indications in the metallurgy of cadmium telluride, we describe the realisation of several structures types, evaporation of a cadmium telluride's layer, diffusion of gold or copper, metal semiconductor contact. Measures of current-voltage characteristics and capacity allow the determination of possibility of nuclear detection with this structures and state precisely some parameters. In the third chapter range's measures of α rays are compared with the first chapter's theoretical results. Results of α ray spectroscopy obtained with three detectors are described and show the possibility of cadmium telluride in this way. Detection of gamma ray at last justify the choice of this material, but the results obtained here show the progress to do in cadmium telluride metallurgy. (author) [fr

  17. In-situ gamma-ray assay of the west cell line in the 235-F plutonium fuel form facility

    Energy Technology Data Exchange (ETDEWEB)

    Couture, A. H. [Savannah River Site (SRS), Aiken, SC (United States); Diprete, D. [Savannah River Site (SRS), Aiken, SC (United States)

    2014-09-01

    On August 29th, 2013, scientists from SRNL took a series of in-situ gamma-ray measurements in the maintenance trench beneath Cells 6-9 on the west line of the PuFF facility using an uncollimated, highpurity germanium detector. The detector efficiency was estimated using a combination of MCNP simulations and empirical measurements. Data analysis was performed using three gamma-rays emitted by Pu-238 (99.85 keV, 152.7 keV, and 766.4 keV) providing three independent estimates of the mass of Pu-238 holdup in each of the cells. The weighted mean of these three results was used as the best estimate of Pu-238 holdup in the West Cell Line of PuFF. The results of the assay measurements are found in the table below along with the results from the scoping assay performed in 2006. All uncertainties in this table (as well as the rest of the report) are given as 1σ. The total holdup in the West Cell Line was 2.4 ± 0.7 grams. This result is 0.6 g higher than the previous estimate, a 0.4σ difference.

  18. Multiple-reflection time-of-flight mass spectrometry for in situ applications

    International Nuclear Information System (INIS)

    Dickel, T.; Plaß, W.R.; Lang, J.; Ebert, J.; Geissel, H.; Haettner, E.; Jesch, C.; Lippert, W.; Petrick, M.; Scheidenberger, C.; Yavor, M.I.

    2013-01-01

    Highlights: • MR-TOF-MS: huge potential in chemistry, medicine, space science, homeland security. • Compact MR-TOF-MS (length ∼30 cm) with very high mass resolving powers (10 5 ). • Combination of high resolving power (>10 5 ), mobility, API for in situ measurements. • Envisaged applications of mobile MR-TOF-MS. -- Abstract: Multiple-reflection time-of-flight mass spectrometers (MR-TOF-MS) have recently been installed at different low-energy radioactive ion beam facilities. They are used as isobar separators with high ion capacity and as mass spectrometers with high mass resolving power and accuracy for short-lived nuclei. Furthermore, MR-TOF-MS have a huge potential for applications in other fields, such as chemistry, biology, medicine, space science, and homeland security. The development, commissioning and results of an MR-TOF-MS is presented, which serves as proof-of-principle to show that very high mass resolving powers (∼10 5 ) can be achieved in a compact device (length ∼30 cm). Based on this work, an MR-TOF-MS for in situ application has been designed. For the first time, this device combines very high mass resolving power (>10 5 ), mobility, and an atmospheric pressure inlet in one instrument. It will enable in situ measurements without sample preparation at very high mass accuracy. Envisaged applications of this mobile MR-TOF-MS are discussed

  19. Gamma-ray spectroscopy of in-situ SNM with the M3CA and a new room-temperature detector

    International Nuclear Information System (INIS)

    Russo, P.A.; Close, D.A.; Hsue, S.T.

    1995-01-01

    Gamma-ray spectroscopy with real-time readout is applied in portable and fixed (continuous) quantitative assays of in-situ special nuclear materials (SNM). Hold-up, in-process inventory, stored inventory, and dynamic materials are several categories of SNM for which in-situ measurements are required. Conventional room-temperature gamma-ray detectors serve in a limited number of these applications, but these detectors have a low gamma energy resolution that limits their sensitivities. It is necessary to develope room temperature detectors with improved sensitivity, and the promising approach is an elegant new detector design that benefits from the recent advances in solid-state materials technology for the production of large, good-quality crystals of CdZnTe. The detector operates with a miniature, modular, multi-channel analyzer. Characteristics of this detector are briefly discussed in this paper

  20. In-situ suspended aggregate microextraction of gold nanoparticles from water samples and determination by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Choleva, Tatiana G; Kappi, Foteini A; Tsogas, George Z; Vlessidis, Athanasios G; Giokas, Dimosthenis L

    2016-05-01

    This work describes a new method for the extraction and determination of gold nanoparticles in environmental samples by means of in-situ suspended aggregate microextraction and electrothermal atomic absorption spectrometry. The method relies on the in-situ formation of a supramolecular aggregate phase through ion-association between a cationic surfactant and a benzene sulfonic acid derivative. Gold nanoparticles are physically entrapped into the aggregate phase which is separated from the bulk aqueous solution by vacuum filtration on the surface of a cellulose filter in the form of a thin film. The film is removed from the filter surface and is dissociated into an acidified methanolic solution which is used for analysis. Under the optimized experimental conditions, gold nanoparticles can be efficiently extracted from water samples with recovery rates between 81.0-93.3%, precision 5.4-12.0% and detection limits as low as 75femtomolL(-1) using only 20mL of sample volume. The satisfactory analytical features of the method along with the simplicity indicate the efficiency of this new approach to adequately collect and extract gold nanoparticle species from water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Towards Molecular Characterization of Mineral-Organic Matter Interface Using In Situ Liquid Secondary Ion Mass Spectrometry

    Science.gov (United States)

    Zhu, Z.; Yu, X. Y.

    2017-12-01

    Organo-Mineral-Microbe interactions in terrestrial ecosystems are of great interest. Quite a few models have been developed through extensive efforts in this field. However, predictions from current models are far from being accurate, and many debates still exist. One of the major reasons is that most experimental data generated from bulk analysis, and the information of molecular dynamics occurring at mineral-organic matter interface is rare. Such information has been difficult to obtain, due to lack of suitable in situ analysis tools. Recently, we have developed in situ liquid secondary ion mass spectrometry (SIMS) at Pacific Northwest National Laboratory1, and it has shown promise to provide both elemental and molecular information at vacuum-liquid and solid-liquid interfaces.2 In this presentation, we demonstrate that in situ liquid SIMS can provide critical molecular information at solid substrate-live biofilm interface.3 Shewanella oneidensis is used as a model micro-organism and silicon nitride as a model mineral surface. Of particular interest, biologically relevant water clusters have been first observed in the living biofilms. Characteristic fragments of biofilm matrix components such as proteins, polysaccharides, and lipids can be molecularly examined. Furthermore, characteristic fatty acids (e.g., palmitic acid), quinolone signal, and riboflavin fragments were found to respond after the biofilm is treated with Cr(VI), leading to biofilm dispersal. Significant changes in water clusters and quorum sensing signals indicative of intercellular communication in the aqueous environment were observed, suggesting that they might result in fatty acid synthesis and inhibition of riboflavin production. The Cr(VI) reduction seems to follow the Mtr pathway leading to Cr(III) formation. Our approach potentially opens a new avenue for in-situ understanding of mineral-organo or mineral-microbe interfaces using in situ liquid SIMS and super resolution fluorescence

  2. Two-Step Resonance-Enhanced Desorption Laser Mass Spectrometry for In Situ Analysis of Organic-Rich Environments

    Science.gov (United States)

    Getty, S. A.; Grubisic, A.; Uckert, K.; Li, X.; Cornish, T.; Cook, J. E.; Brinckerhoff, W. B.

    2016-01-01

    A wide diversity of planetary surfaces in the solar system represent high priority targets for in situ compositional and contextual analysis as part of future missions. The planned mission portfolio will inform our knowledge of the chemistry at play on Mars, icy moons, comets, and primitive asteroids, which can lead to advances in our understanding of the interplay between inorganic and organic building blocks that led to the evolution of habitable environments on Earth and beyond. In many of these environments, the presence of water or aqueously altered mineralogy is an important indicator of habitable environments that are present or may have been present in the past. As a result, the search for complex organic chemistry that may imply the presence of a feedstock, if not an inventory of biosignatures, is naturally aligned with targeted analyses of water-rich surface materials. Here we describe the two-step laser mass spectrometry (L2MS) analytical technique that has seen broad application in the study of organics in meteoritic samples, now demonstrated to be compatible with an in situ investigation with technique improvements to target high priority planetary environments as part of a future scientific payload. An ultraviolet (UV) pulsed laser is used in previous and current embodiments of laser desorption/ionization mass spectrometry (LDMS) to produce ionized species traceable to the mineral and organic composition of a planetary surface sample. L2MS, an advanced technique in laser mass spectrometry, is selective to the aromatic organic fraction of a complex sample, which can provide additional sensitivity and confidence in the detection of specific compound structures. Use of a compact two-step laser mass spectrometer prototype has been previously reported to provide specificity to key aromatic species, such as PAHs, nucleobases, and certain amino acids. Recent improvements in this technique have focused on the interaction between the mineral matrix and the

  3. Comparison on in situ and laboratory gamma-ray spectroscopy of ...

    African Journals Online (AJOL)

    In situ - ray spectroscopic method of measeruments, using the calibration factor by Zombori et al, and laboratory method for soil samples were carried out in Ibadan, SW Nigeria. The average specific activities of 40K, 238U and 232Th in the soil were 299.0 16.5 Bqkg-1, 40.0 5.8 Bqkg-1 and 95.0 7.8 Bqkg-1, respectively, by in ...

  4. Calibration comparative results for X - and gamma ray spectrometry with HPGe and BEGe detectors for a radon reference chamber

    International Nuclear Information System (INIS)

    Zoran, Maria; Paul, Annette; Arnold, Dirk

    2002-01-01

    Inhaled decay products of 222 Rn are the dominant components of the natural radiation exposure being responsible for about 30% of the whole human radioactive exposure. Field instruments for 222 Rn and his progeny monitoring are calibrated in 'radon climate rooms', where it is possible to vary and monitor 222 Rn and the indoor air parameters ( temperature, humidity, ventilation rate, aerosol concentration). German radon reference chamber used was developed and installed at the Physikalisch-Technische Bundesanstalt in order to serve as a metrological standard for radon and his progeny calibration of active and passive, indoor and outdoor radon monitoring devices in air climate. The basic parts of experimental setup for this γ and X -ray spectrometry analysis consists of a γ-X ray source in a lead shield/collimator, the detectors, the electronics necessary for pulse-height analysis (PHA) to obtain energy spectra. For calibrating system with 226 Ra standard sources (multienergy X ray and gamma emitters), two germanium detectors HPGe (12.5 nominal efficiency) and BEGe (22.5 nominal efficiency) were used. Germanium detectors are semiconductor diodes having a P-I-N structure in which the Intrinsic (I) region is sensitive to ionizing radiation, particularly X-rays and gamma rays. The BEGe is designed with an electrode structure that enhances low energy resolution and is fabricated from selected germanium having an impurity profile that improves charge collection (thus resolution and peak shape) at high energies which is really important in analysis of the complex spectra for uranium and finally for 226 Ra. MAESTRO MCA software and GNUPLOT program were used for spectra acquisition and spectra analysis, respectively . The main aim of this paper was to do a comparatively analysis of the detector performances for this radon chamber spectrometric chain. The calibration data analysis includes energy calibrations for both detection systems as well as comparative X and gamma

  5. Soil gamma ray spectrometry of the Buquira river basin, SP, Brazil

    International Nuclear Information System (INIS)

    Rivera, Alice

    2002-12-01

    Natural radioactivity found in rocks and its evaluation been frequently used for studies of environmental geochemistry, particularly those of detection and control of pollutants and the consequent changes in environment after antropic interferences. In this work natural radioactivity in forty nine soil samples in the basin of Buquira river, at the Northeast region of Sao Paulo State, has been analysed and measured with a Ge-HP gamma ray spectrometer. A table with the most relevant results found in rocks is shown and discussed. (author)

  6. Gamma irradiation testing of montan wax barrier materials for in-situ waste containment

    International Nuclear Information System (INIS)

    Soo, P.; Heiser, J.

    1996-02-01

    A scoping study was carried out to quantify the potential use of a montan wax as a barrier material for subsurface use. If it possesses resistance to chemical and structural change, it could be used in a barrier to minimize the migration of contaminants from their storage or disposal locations. Properties that were evaluated included hardness, melting point, molecular weight, and biodegradation as a function of gamma radiation dose. The main emphasis was to quantify the wax's long-term ability to withstand radiation-induced mechanical, chemical, and microbial degradation

  7. In situ quantitative determination of transuranic elements in areas of high-level gamma radiation

    International Nuclear Information System (INIS)

    Brodzinski, R.L.; Wogman, N.A.

    1978-01-01

    A technique is described for passive neutron monitoring of transuranic elements. The method provides quantitative determinations of transuranic element concentrations in a variety of field situations where no other measurement method is possible. The technique can measure concentrations of transuranic oxides as low as 8 nCi/cm 3 and is capable of operating in gamma radiation fields up to megarads per hour. Information on chemical and isotopic composition can also be obtained from the data. Several successful applications of the technique are discussed

  8. An automated measuring system based on gamma spectrometry with HPGe detectors

    International Nuclear Information System (INIS)

    Mala, Helena; Rulik, Petr; Hyza, Miroslav; Dragounova, Lenka; Helebrant, Jan; Hroznicek, Marek; Jelinek, Pavel; Zak, Jan

    2016-01-01

    An automatic system for unattended gamma spectrometric measurements of bulk samples ( “Gamma Automat”, GA) was developed by the National Radiation Protection Institute and Nuvia, Inc. as a part of a research project. The basic parts include a detection system with two HPGe detectors in the lead shielded chambers, sample changer, sample tray and a control unit. The GA enables counting in two geometries: (i) with cylindrical containers (200 ml) either one placed at the detector face or 2-6 placed around the detector or (II) with Marinelli beakers (600 ml). The shelf can accommodate 180 cylindrical containers or 54 Marinelli beakers. Samples are changed by a robotic arm. The sample data and the analysis required are passed to the GA by a matrix code (generated within the laboratory system) located on the lid of a sample container, whence the GA reads information. Spectrometric analysis is performed automatically after the counting. Current status of GA can be remotely monitored. Information about the activities of the GA, measurement completion or failures of the equipment are automatically generated and sent to a mobile phone and the operator PC. A presentation of the GA is available at https://youtu.be/1lQhfo0Fljo. (orig.)

  9. Software ASPRO-NUC. Gamma-ray spectrometry, routine NAA, isotope identification and data management

    International Nuclear Information System (INIS)

    Kolotov, V.P.; Atrashkevich, V.V.

    1995-01-01

    The software ASPRO-NUC is based on new improved algorithms suggested and tested in the laboratory and intended for routine analysis. The package consists of the program ASPRO for gamma-ray spectra processing (peak search, multiplets deconvolution by means of method of moments, computation of correction coefficient for geometry and material of radioactive source), a program for isotope identification and a program for NAA by means of relative standardization. All output information is loaded into a data base (Paradox v.3.5 format) for supporting of queries, creation of reports, planning of routine analysis, estimation of expenses, supporting of network of analytical survey, etc. The ASPRO-NUC package also includes a vast nuclear data base containing evaluated decay and activation data (reactor, generator of fast neutrons, Cf-252 source). The data base environment allows for easy integration of a gamma spectrometer into a flexible information shell and the creation of a logical system for information management. (author) 15 refs.; 2 figs.; 2 tabs

  10. Determination of Beryllium-7 in Water Hyacinth Using Gamma-Ray Spectrometry

    International Nuclear Information System (INIS)

    Yimchalam, Nopporn; Chankow, Nares; Yangchauy, Udon

    2009-07-01

    Full text: Beryllium-7 (7 B e) is a cosmogenic radionuclide produced in the upper atmosphere and enters the lower atmosphere by atmospheric circulation processes. About 90% of 7 B e decays directly through electron capture to 7 L i at ground state and about 10% to 7 L i at 1 s t excited state followed by 477.6 keV gamma-ray emission with a half-life of 53.3 days. The aim of this research was to measure 7 B e activity in environmental samples including water and aquatic plants. From the preliminary investigation by measurement of the 477.6 keV gamma-ray peak, 7 B e could be found in fresh Water Hyacinth samples. Thus, Water Hyacinth samples were then collected at different times of the year 2007 - 2008 in an area of Bang Khaen campus of Kasetsart University for determination of 7 B e activity using a HPGe detector. It was found that 7 B e specific activity was about 4-7 Bq/kg in the samples collected in rainy season during August-October 2007 and in June 2008 but could not detect in dry seasons i.e. summer and winter. The specific activity of 7 B e in Water Hyacinth sample depended on rainfalls as expected

  11. Study on the natural radioactivity from the region of Presidente Figueiredo (AM), Brazil, using gamma spectrometry; Estudo da radioatividade natural da regiao de Presidente Figueiredo (AM) utilizando espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, Jose Ribamar Silveira

    1999-07-01

    A gamma spectrometry profile was carried out along BR174 highway, that crosses some lithostratigraphic units of the North portion of the Sedimentary Basin of Amazon. Measurements in situ were realized in 116 points, 1 km apart, using a GAD-6 gamma-spectrometer and samples of rocks and soils were collected in geologically representative points, for gamma measurements using a shielded detector of NaI(Tl) available in the Nuclear Geophysics Laboratory of IAG/USP. The criterion used for evaluating the reliability degree of the concentration values of eU (ppm), eTh (ppm) and %K was to establish mathematically detection limits, for all measurement points. Every these points had been located using GPS with accuracy of 50 m to become possible a future detailed study. The purpose of matching portable gamma spectrometer and laboratory determinations was to compare the 2 techniques, using the criterion of detectability limits, and to verify the influence of {sup 222} Rn atmospheric radioactive gas in field measurements. In the case of portable detector, it allows fast measurements and the sensor 'sees' a big volume of material (rock, soil...), that makes it more representative. In some situations where atmospheric phenomena of thermal inversion occurs, measurement can be affected by the {sup 222} Rn cosmic background. Presence of radon daughter elements, associated with aerosols, in this tropical environment (high values of temperature and humidity), where the speed of the wind that could exhaust this gas is practically zero. It is observed that the values of concentration in the some points, got with these 2 techniques, have the same trend, and the stretches where peaks of concentration of K also occur and U and Th are associated with the presence of granite out corps, great boulders, and clay soils from weathering of these rocks. (author)

  12. Application of gamma ray spectrometry and atomic absorption spectrometry for monitoring some radionuclides and heavy metals in sediments from the sudanese red sea coast

    International Nuclear Information System (INIS)

    Idris, A. M.; Eltayeb, M. A.

    2004-01-01

    A total of 31 surface sediment samples were collected from port-sudan harbour, sawakin harbour and the fringing reefs area that are located along the Sudanese coast of the red sea. The sampling was performed to provide good spatial coverage taking into account man's activity in port-sudan harbour and the fringing reefs area. the bulk samples were analyzed for some natural and anthropogenic radionuclides ( 226 Ra, 228 Ra, 40 K, 137 Cs) using direct gamma-ray spectrometry. Concentration of some heavy metals were determined in five fractions with grain-size of 1.000-0.500 m lm, 0.500-0.250 m lm, 0.250-0.125 m lm, 0.125-0.063 m lm and less than 0.063 m lm. The fractionation process was performed using dry sieving method. A total of 155 sub-samples (fractions) were digested by wet digestion method and analyzed for Mn, Fe, Ni, Cu, Zn, and Pb using flame atomic absorption spectrometry. Quality assurance of the obtained data was achieved through the analysis of certified reference materials. the radioactivity concentration ranges of ( 226 Ra, 228 Ra, and 40 K,) are 2.5-25.1b/kg, 2.1-13.1b q/kg,21.6- 429 Bq/kg, respectively. For ( 137 Cs)measurements, the highest value is 8.3 Bq/kg while most of samples were below the detection limits of the system. The concentration ranges of Mn, Fe, Cu, Zn, and Pb are 53.3-819 mg/kg, 1.4-51 mg/g, 8-131 mg/kg 9.5-113 mg/kg, 18.4-142 mg/kg, and 4.0-26.6 mg/kg, respectively. The granulometric normalization shows that some samples were subjected to anthropogenic activities. This finding was reinforced by results that were obtained from enrichment factor calculations and statistical multivariate analysis that is principal component analysis (Pca), also the Pca indicates that silt/clay fraction (>0.063 m lm ) is the dominant source for the emission of anthropogenic activities. From viewpoint of mineralogical composition the cluster analysis has distributed the samples into tow clusters. Dominant elements in sediments (Mn and Fe ) recorded

  13. In situ analysis of soybeans and nuts by probe electrospray ionization mass spectrometry.

    Science.gov (United States)

    Petroselli, Gabriela; Mandal, Mridul K; Chen, Lee C; Hiraoka, Kenzo; Nonami, Hiroshi; Erra-Balsells, Rosa

    2015-04-01

    The probe electrospray ionization (PESI) is an ESI-based ionization technique that generates electrospray from the tip of a solid metal needle. In the present work, we describe the PESI mass spectra obtained by in situ measurement of soybeans and several nuts (peanuts, walnuts, cashew nuts, macadamia nuts and almonds) using different solid needles as sampling probes. It was found that PESI-MS is a valuable approach for in situ lipid analysis of these seeds. The phospholipid and triacylglycerol PESI spectra of different nuts and soybean were compared by principal component analysis (PCA). PCA shows significant differences among the data of each family of seeds. Methanolic extracts of nuts and soybean were exposed to air and sunlight for several days. PESI mass spectra were recorded before and after the treatment. Along the aging of the oil (rancidification), the formation of oxidated species with variable number of hydroperoxide groups could be observed in the PESI spectra. The relative intensity of oxidated triacylglycerols signals increased with days of exposition. Monitoring sensitivity of PESI-MS was high. This method provides a fast, simple and sensitive technique for the analysis (detection and characterization) of lipids in seed tissue and degree of oxidation of the oil samples. Copyright © 2015 John Wiley & Sons, Ltd.

  14. The Laser Ablation Ion Funnel: Sampling for in situ Mass Spectrometry on Mars

    Science.gov (United States)

    Johnson, Paul V.; Hodyss, Robert; Tang, Keqi; Brinckerhoff, William B.; Smith, Richard D.

    2011-01-01

    A considerable investment has been made by NASA and other space agencies to develop instrumentation suitable for in situ analytical investigation of extra terrestrial bodies including various mass spectrometers (time-of-flight, quadrupole ion trap, quadrupole mass filters, etc.). However, the front-end sample handling that is needed to collect and prepare samples for interrogation by such instrumentation remains underdeveloped. Here we describe a novel approach tailored to the exploration of Mars where ions are created in the ambient atmosphere via laser ablation and then efficiently transported into a mass spectrometer for in situ analysis using an electrodynamic ion funnel. This concept would enable elemental and isotopic analysis of geological samples with the analysis of desorbed organic material a possibility as well. Such an instrument would be suitable for inclusion on all potential missions currently being considered such as the Mid-Range Rover, the Astrobiology Field Laboratory, and Mars Sample Return (i.e., as a sample pre-selection triage instrument), among others.

  15. Calibration and performance of a real-time gamma-ray spectrometry water monitor using a LaBr3(Ce) detector

    Science.gov (United States)

    Prieto, E.; Casanovas, R.; Salvadó, M.

    2018-03-01

    A scintillation gamma-ray spectrometry water monitor with a 2″ × 2″ LaBr3(Ce) detector was characterized in this study. This monitor measures gamma-ray spectra of river water. Energy and resolution calibrations were performed experimentally, whereas the detector efficiency was determined using Monte Carlo simulations with EGS5 code system. Values of the minimum detectable activity concentrations for 131I and 137Cs were calculated for different integration times. As an example of the monitor performance after calibration, a radiological increment during a rainfall episode was studied.

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  17. An investigation of the repeatability of calibration factors in gamma-ray spectrometry of geological materials

    International Nuclear Information System (INIS)

    Mustapha, A.O.; Patel, J.P.; Rathore, I.V.S.; Hashim, N.O.; Otwoma, D.

    2004-01-01

    A NaI(Tl)-based gamma spectrometer for the analysis of geological materials was calibrated using the IAEA reference materials RGU-1, RGTH-1 and RGK-1. To simulate typical geological samples, two additional standards were prepared from aliquots of the three reference materials. The reproducibility of the instrument calibration factors (CFs) was tested by repeated measurements of the pure IAEA reference materials and the mixed samples in a reproducible counting geometry. The results were analysed using a two-way classification analysis of variance; it was found that the variance in the CFs is significantly higher between standards than it is between measurements. Allowance should be made for this when estimating uncertainties in measurements with the NaI(Tl) spectrometers

  18. Environmental monitoring system based on airborne gamma ray spectrometry developed at Geoinstitut Beograd

    International Nuclear Information System (INIS)

    Milojevic, M.; Strumberger, V.

    1997-01-01

    The continuous hazard of nuclear reactor failures, which may exceed in consequences that of the Chernobyl accident on 26 April 1986, makes it imperative for us to develop and introduce soil, water and air contamination control systems to protect the environment. A most efficient means of the contamination control at the artificial radioactive radiation sources is the complex MONITORING SYSTEM controlled from a centre by competent and recognised experts. Such systems have been used for years now many western world countries (USA, Canada, Sweden, etc.). The modest purpose of this paper is at least to leave a trace of the efforts, both individual and of the institute, made in developing a component of the monitoring system - airborne gamma-ray contamination control, which in western systems is a principal technique of remote detection. (author)

  19. Data processing in gamma spectrometry. Application to the decay schemes study

    International Nuclear Information System (INIS)

    Boulanger, J.P.

    1969-06-01

    The purpose of this thesis is the processing of the data issued from a gamma spectrometer, and its applications to the decay schemes study. The mathematical analysis of the full energy peaks, in connection with the very good resolution of semi-conductor detectors, leads to a very accurate determination of the energies. The resolution of complex spectra by the least squares method, completed by a spectra generating process, allows the calculation of branching ratios. Then, the handling of the two dimensional experiments permits the coincidence exam. For each of these methods, the calculation principle, then the systematics tests realized in order to prove their validity and to determine their application ranges as well as some experimental results appropriate to illustrate their possibilities, are presented. The energies of some nuclides, frequently used as standards have been thus measured and the decay schemes of 134 Cs and 110m Ag determined precisely. (author) [fr

  20. Applications of gamma spectrometry to the study of the marine environment of nuclear fuel reprocessing plants

    International Nuclear Information System (INIS)

    Lapicque, G.

    1975-01-01

    The paper surveys such methods and assemblies as are conceivable for studies of marine environments with gamma emitting radionuclides. An important application is found in the case of nuclear fuel reprocessing plants, which occupy a key position in any large scale program for atomic power plants. The tracers chosen are 137 Cs and 106 Ru, which constitute an important part of liquid wastes. The characteristics of two assemblies using NaI(Tl) crystals are given. Their thresholds are of the order of a few pCi/l to a few 10pCi/l for a counting time of one hour, respectively for 137 Cs and 106 Ru. These equipments are utilised for the monitoring of the Hague reprocessing plant, one of the most important in Europe. They yield data on the circulation, diffusion and sedimentation of liquid wastes. Measured activities have always been found to be much lower than maximum admissible concentrations (M.A.C.) [fr

  1. Spectrometry and dosimetric evaluation of the gamma-ray emissions of 241Am

    International Nuclear Information System (INIS)

    Bradley, D.A.; Chong, C.S.

    1991-01-01

    New, detailed measurements have been made of the photon spectrum of the radionuclide 241 Am. Observations, recorded for a 95% confidence level over local background, provide affirmation of a number of lines previously considered to be of equivocal existence. A number of hitherto unreported emissions are similarly observed. Peak areas, expressed as a percentage of that for the 59.54 keV emission, have been ascribed to all lines of the detailed spectrum. This leads to an estimated increase in the value of exposure calculated from the measured fluence spectrum, relative to that from the 59.54 keV line, of (3.1 ± 0.8)%, taking into account all emissions beyond the predominating 59.54 keV gamma-ray emission. (author)

  2. Early detection of radioactive fall-out by gamma-spectrometry

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, K.

    2003-01-01

    Radioactive fallout should be detected as early as possible. A new and efficient method for detection of low-level irradiation from manmade radioactivity is developed. Radiation abnormalities are detectable down to air kerma rate, of 0.5 to 1.0 nGy h(-1) for Cs-137 and even lower for I-131...... For multi-gamma energy radioactivity the detection level is 2.6-3.5 nGy h(-1). A standard NaI detector and a 512-channel analyser are used together with noise adjusted singular value decomposition (NASVD). Statistical noise is removed and the measured spectra are reproduced using spectral components...... radioactive sources need to be detected....

  3. Radioactivity analysis of sounai region by gamma spectrometry and radiation monitoring network

    International Nuclear Information System (INIS)

    El-Mongy, S.A.; Abd El-Aziz, N.; El-Tahawy, M.S.; Morsy, S.

    2000-01-01

    Levels of natural and man-made radioactivity in soil and plant of southern sinai region are investigated by using Gamma- spectrometric analysis. The found average concentrations of 2 26Ra ( 2 38U) series, 2 32Th series and 4 0K are 20.2, 17.0 and 378.8 Bq/Kg respectively. The fall out 1 37Cs is the only man-made radionuclide detected with concentrations not exceed 3 Bq/Kg (dry weight) in both soil and plant samples. The effective dose rate equivalent are 106, 129, 114 and 104 n Sv/h for El-Tour, Sharm El-Shaik, Nwuiba and Taba as detected by the corresponding stations of the national radiation monitoring network (NRMN) respectively. The radium equivalent (Req) and absorbed dose rate resulted due to the natural radionuclides in soil are also calculated and given

  4. Radiometric analysis of construction materials using HPGe gamma-ray spectrometry.

    Science.gov (United States)

    Khandaker, M U; Jojo, P J; Kassim, H A; Amin, Y M

    2012-11-01

    Concentrations of primordial radionuclides in common construction materials collected from the south-west coastal region of India were determined using a high-purity germanium gamma-ray spectrometer. Average specific activities (Bq kg(-1)) for (238)U((226)Ra) in cement, brick, soil and stone samples were obtained as 54 ± 13, 21 ± 4, 50 ± 12 and 46 ± 8, respectively. Respective values of (232)Th were obtained as 65 ± 10, 21 ± 3, 58 ± 10 and 57 ± 12. Concentrations of (40)K radionuclide in cement, brick, soil and stone samples were found to be 440 ± 91, 290 ± 20, 380 ± 61 and 432 ± 64, respectively. To evaluate the radiological hazards, radium equivalent activity, various hazard indices, absorbed dose rate and annual effective dose have been calculated, and compared with the literature values. Obtained data could be used as reference information to assess any radiological contamination due to construction materials in future.

  5. Assessment of the equilibrium of Th-228 and Ra-228 by gamma-ray spectrometry in mangrove soils

    Energy Technology Data Exchange (ETDEWEB)

    Paiva, Jose Daniel S.; Farias, Emerson E.G.; Franca, Elvis J. De, E-mail: paivajds@gmail.com, E-mail: emersonemiliano@yahoo.com.br, E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2015-07-01

    The mangrove environment consists of soil containing high organic matter, characterized by the influence of continental and oceanic waters, relatively high concentrations of salts and exuberant vegetation. Mangroves also present high dynamics of chemical compound cycling, in which soils become quite relevant due to the influence of continental and oceanic sediments. Taking into account the different sources and transport of radionuclides within the mangrove environment, this study focused at the radioactive equilibrium of Thorium-232 series radionuclides, especially the Ra-228 and Thorium-228. For this, soil samples were collected in the crown projection of tree species from two mangroves located in the municipalities of Olinda/Recife and Rio Formoso, Pernambuco State, Brazil. The material was oven-dried and milled and test portions of 38 g were transferred to cylindrical vials and sealed. After 30 days, the natural radioactivity was measured during 80,000 seconds using High Resolution Gamma-Ray Spectrometry with a germanium detector of 2.2 keV of resolution at the 1,332 keV Co-60 photopeak. For Ra-228 determination, 911 keV gamma-ray line (Ac-228) were employed, while 238 keV (Pb-212) and 727 keV (Bi-212) were considered for estimating activity concentrations of Th-228. As a result, Ra-228 and Th 228 were in equilibrium since the activity concentrations (ranging from 35 Bq/kg to 50 Bq/kg) were not significantly different at the 95% confidence level. The results have confirmed that, even for environments of high dynamics such as mangroves, radioactive equilibrium of Th-228 and Ra-228 was kept, corroborating Th-232 determination in mangrove soils. (author)

  6. Assessment of the equilibrium of Th-228 and Ra-228 by gamma-ray spectrometry in mangrove soils

    International Nuclear Information System (INIS)

    Paiva, Jose Daniel S.; Farias, Emerson E.G.; Franca, Elvis J. De

    2015-01-01

    The mangrove environment consists of soil containing high organic matter, characterized by the influence of continental and oceanic waters, relatively high concentrations of salts and exuberant vegetation. Mangroves also present high dynamics of chemical compound cycling, in which soils become quite relevant due to the influence of continental and oceanic sediments. Taking into account the different sources and transport of radionuclides within the mangrove environment, this study focused at the radioactive equilibrium of Thorium-232 series radionuclides, especially the Ra-228 and Thorium-228. For this, soil samples were collected in the crown projection of tree species from two mangroves located in the municipalities of Olinda/Recife and Rio Formoso, Pernambuco State, Brazil. The material was oven-dried and milled and test portions of 38 g were transferred to cylindrical vials and sealed. After 30 days, the natural radioactivity was measured during 80,000 seconds using High Resolution Gamma-Ray Spectrometry with a germanium detector of 2.2 keV of resolution at the 1,332 keV Co-60 photopeak. For Ra-228 determination, 911 keV gamma-ray line (Ac-228) were employed, while 238 keV (Pb-212) and 727 keV (Bi-212) were considered for estimating activity concentrations of Th-228. As a result, Ra-228 and Th 228 were in equilibrium since the activity concentrations (ranging from 35 Bq/kg to 50 Bq/kg) were not significantly different at the 95% confidence level. The results have confirmed that, even for environments of high dynamics such as mangroves, radioactive equilibrium of Th-228 and Ra-228 was kept, corroborating Th-232 determination in mangrove soils. (author)

  7. Radionuclide content of simulated and fully radioactive SRLLL waste glasses: comparison of results from ICP-MS, gamma spectrometry and alpha spectrometry

    International Nuclear Information System (INIS)

    Wolf, S.F.; Bates, J.K.

    1995-01-01

    We have measured the transuranic content of two transuranic=doped, simulated waste glasses, using inductively coupled plasma-mass spectrometry (ICP-MS), γ-spectrometry, and α-spectrometry. Average concentrations measured by each technique were within ± 10% of the as-doped concentrations. We also report the transuranic content of three fully radioactive SRL waste glasses that were determined using γ- and α-spectrometry measurements to deconvolute isobaric interferences present in the ICP-MS analyses

  8. Prospecting for Lunar Oxygen with Gamma-Ray Spectrometry and Multispectral Imaging

    Science.gov (United States)

    Allen, Carlton C.; Weitz, Catherine M.; McKay, David S.

    1998-01-01

    Oxygen is a potentially abundant lunar resource that could be used for life support and spacecraft propulsion. The recent identification by Prospector of ice at the lunar poles has renewed interest in the use of in situ 0 production to supply a future base. Siting a lunar base at any significant distance from the poles, however, would require costly transport of 0 or its extraction from the local regolith. More than 20 different processes have been proposed for regolith 0 extraction. Among the simplest and best studied of these processes is the reduction of oxides in lunar minerals and glass using H gas. Oxides, predominantly those containing FeO, are first reduced; 0 is then liberated to form water. The water is then electrolyzed to yield 0, and the H is recycled to the reactor.

  9. Theoretical determination of gamma spectrometry systems efficiency based on probability functions. Application to self-attenuation correction factors

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, Manuel, E-mail: manuel.barrera@uca.es [Escuela Superior de Ingeniería, University of Cadiz, Avda, Universidad de Cadiz 10, 11519 Puerto Real, Cadiz (Spain); Suarez-Llorens, Alfonso [Facultad de Ciencias, University of Cadiz, Avda, Rep. Saharaui s/n, 11510 Puerto Real, Cadiz (Spain); Casas-Ruiz, Melquiades; Alonso, José J.; Vidal, Juan [CEIMAR, University of Cadiz, Avda, Rep. Saharaui s/n, 11510 Puerto Real, Cádiz (Spain)

    2017-05-11

    A generic theoretical methodology for the calculation of the efficiency of gamma spectrometry systems is introduced in this work. The procedure is valid for any type of source and detector and can be applied to determine the full energy peak and the total efficiency of any source-detector system. The methodology is based on the idea of underlying probability of detection, which describes the physical model for the detection of the gamma radiation at the particular studied situation. This probability depends explicitly on the direction of the gamma radiation, allowing the use of this dependence the development of more realistic and complex models than the traditional models based on the point source integration. The probability function that has to be employed in practice must reproduce the relevant characteristics of the detection process occurring at the particular studied situation. Once the probability is defined, the efficiency calculations can be performed in general by using numerical methods. Monte Carlo integration procedure is especially useful to perform the calculations when complex probability functions are used. The methodology can be used for the direct determination of the efficiency and also for the calculation of corrections that require this determination of the efficiency, as it is the case of coincidence summing, geometric or self-attenuation corrections. In particular, we have applied the procedure to obtain some of the classical self-attenuation correction factors usually employed to correct for the sample attenuation of cylindrical geometry sources. The methodology clarifies the theoretical basis and approximations associated to each factor, by making explicit the probability which is generally hidden and implicit to each model. It has been shown that most of these self-attenuation correction factors can be derived by using a common underlying probability, having this probability a growing level of complexity as it reproduces more precisely

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  11. Oxygen diluted hexamethyldisiloxane plasmas investigated by means of in situ infrared absorption spectroscopy and mass spectrometry

    Science.gov (United States)

    Magni, D.; Deschenaux, Ch; Hollenstein, Ch; Creatore, A.; Fayet, P.

    2001-01-01

    The gas phase species produced in rf plasmas of hexamethyldisiloxane (HMDSO), Si2O(CH3)6, diluted with oxygen, have been investigated. The complementarity of Fourier transform infrared absorption spectroscopy and mass spectrometry allows the determination of the most abundant neutral components present in the discharge. The measurements reveal that methyl groups (CH3), abundantly formed by the dissociation of the HMDSO molecule, are the precursor for the most abundant species which stem from two kinds of reaction. The first kind of reaction is combustion of CH3 by oxygen-producing formaldehyde (COH2), formic acid (CO2H2), carbon monoxide (CO), carbon dioxide (CO2) and water. It is shown that high mass carbonated radicals, such as SixOyCzHt, first diffuse to the surface and then the carbon is removed by oxygen etching to form CO2. The second is hydrocarbon chemistry promoted by CH3, producing mainly hydrogen (H2), methane (CH4) and acetylene (C2H2).

  12. Measurement of radionuclide activities of uranium-238 series in soil samples by gamma spectrometry: case of Vinaninkarena

    International Nuclear Information System (INIS)

    Randrianantenaina, F.R.

    2017-01-01

    The aim of this work is to determine the activity level of radionuclides of uranium-238 series. Eight soil samples are collected at Rural Commune of Vinaninkarena. After obtaining secular equilibrium, these samples have been measured using gamma spectrometry system in the Nuclear Analyses and Techniques Department of INSTN-Madagascar, with HPGe detector (30 % relative efficiency) and a Genie 2000 software. Activities obtained vary from (78±2)Bq.kg -1 to (49 231 ± 415)Bq.kg -1 . Among these eight samples, three activity levels are shown. Low activity is an activity which has value lower or equal to (89±3)Bq.kg -1 . Average activity is an activity which has value between (186± 1)Bq.kg -1 and (1049 ±7)Bq.kg -1 . And high activity is an activity which has value higher or equal to (14501±209)Bq.kg -1 . According to UNSCEAR 2000, these value are all higher than the world average value which is 35 Bq.kg -1 .It is due to the localities of sampling points. The variation of the activity level depends on radionuclide concentration of uranium-238 series in the soil. [fr

  13. Measurement of short-lived radon progenies by simultaneous alpha gamma-spectrometry at the German radon reference chamber

    CERN Document Server

    Paul, A; Honig, A; Sulima, T; Buchholz, A; Keyser, U

    1999-01-01

    In the German radon reference chamber, the short-lived radon progenies are separated by a sample tube according to the attached or unattached fraction, while their activity concentration is afterwards measured by simultaneous alpha- and gamma-spectrometry. The results are expressed by the equilibrium factor F and the unattached fraction f sub p (International Commission on Radiological Protection, ICRP Publication 50, Ann. ICRP 17 (1987) 1). Both F and f sub p , can be therefore studied with respect to the full set of environmental parameters, e.g. temperature, humidity, air pressure and aerosol concentration (Honig et al., Nucl. Instr. and Meth. A 416 (1998) 525). Up to now, well-defined and stable equilibrium factors in the interval from 0.1 to 1.0 have been established. In correlation with this, the unattached fraction can be varied from 0.01 to 0.9. The sample and measuring technique for the short-lived radon progenies described in this work is the basis for fundamental studies with regard to the equilibr...

  14. Measurement of 235U enrichment in UF6 by passive gamma spectrometry

    International Nuclear Information System (INIS)

    Sawai, Hideo; Ochiai, Ken-ichi; Kaya, Akira

    1979-01-01

    For the assay of UF 6 , a single-channel analyzer (SCA) system of a passive gamma spectrometer has been developed. Basic measuring conditions were studied: such as the effects of sample density and heterogeneity and the effects of cylinder material and wall thickness. Called ''enrichment analyzer'', the system is operated to carry out the measurement and calculation of 235 U enrichment by a directive of the program in a calculator. The resulting data are available in real time output. Measurements were carried out in two modes: ''all way'' mode which measured in the rotation of the cylinder and the up-and-down motion of the detector, and ''spot'' mode which measured at one point on the cylinder. The average accuracy was about 1.8% in case of the former, and 3.2% in case of the latter. It was shown that the ''all way'' mode is preferable, but the ''spot'' mode is also necessary for the assay of large cylinders such as 30 A type. (J.P.N.)

  15. Characterization of CdTe nuclear detectors for gamma radiation spectrometry

    International Nuclear Information System (INIS)

    Rebondy, Jacques.

    1977-01-01

    The crystallography of CdTe is presented. The characterization of CdTe crystals manufactured at LETI was studied using a spectrometry unit, and an experimental study of surface states and contacts was simultaneously undertaken. A manufacturing process was perfected for the detectors: hand polishing and deposit of a drop of conducting lac. Measurements mode on a great number of materials revealed the interest of chlore doping, the polarization phenomenon associated (the polarization is equivalent to a voltage drop and depends on temperature), the effect of surface states and contacts. It was shown that magnesium doping is a failure and the polarization time constant has a value of about 1 msec. An electron time-of-flight experiment was performed in order to measure the mobilities in the sample at normal temperature: the values obtained are: 70-90 cm 2 /v.sec for holes and 800-1000 cm 2 /v.sec for electrons. A trapping level was observed at 0.14eV in a Cl - doped sample; trapping parameters were estimated for a few samples [fr

  16. A new system of gamma-ray spectrometry for activation analysis

    International Nuclear Information System (INIS)

    Murata, Y.; Hirai, S.; Okamoto, M.; Kakihana, H.

    1977-01-01

    A new system of γ-ray spectrometry GAMA has been designed and constructed. This system performs a precise, quick and automatic activation analysis using the TRIGA-II Research Reactor as a neutron source. The main components are detector system consisted of a high resolution Ge(Li) detector settled in a shielding cabinet and a well-type NaI(Tl) scintillation counter for anti-Compton measurement, and data acquisition and spectra analysis system performed independently by two mini computer. The system has operated for atmospheric aerosols as an example of activation analysis. Through the programs, the GAMA system can output the spectrum itself, the peak energies, their intensities and the nuclides corresponding to each energy within +-ΔE energy unit. Corrections are in progress to use more reliable nuclear data, establish preciser γ-ray mesuring methods and construct a new system selecting one nuclide to one peak energy by utilizing simultaneous measurement with an anti-coincidence method and half-life measurement and so on. (T.G.)

  17. Laser Ablation Electrodynamic Ion Funnel for In Situ Mass Spectrometry on Mars

    Science.gov (United States)

    Johnson, Paul V.; Hodyss, Robert P.; Tang, Keqi; Smith, Richard D.

    2012-01-01

    A front-end instrument, the laser ablation ion funnel, was developed, which would ionize rock and soil samples in the ambient Martian atmosphere, and efficiently transport the product ions into a mass spectrometer for in situ analysis. Laser ablation creates elemental ions from a solid with a high-power pulse within ambient Mars atmospheric conditions. Ions are captured and focused with an ion funnel into a mass spectrometer for analysis. The electrodynamic ion funnel consists of a series of axially concentric ring-shaped electrodes whose inside diameters (IDs) decrease over the length of the funnel. DC potentials are applied to each electrode, producing a smooth potential slope along the axial direction. Two radio-frequency (RF) AC potentials, equal in amplitude and 180 out of phase, are applied alternately to the ring electrodes. This creates an effective potential barrier along the inner surface of the electrode stack. Ions entering the funnel drift axially under the influence of the DC potential while being restricted radially by the effective potential barrier created by the applied RF. The net result is to effectively focus the ions as they traverse the length of the funnel.

  18. Planetary In Situ Sample Analysis with Tandem Two-Step Laser Mass Spectrometry

    Science.gov (United States)

    Brinckerhoff, W. B.; Getty, S. A.; Cornish, T. J.; Ecelberger, S. A.; Li, X.; Merrill Floyd, M. A.; Arevalo, R.; Elsila, J.; Callahan, M. P.

    2012-12-01

    Future surface missions to comets and outer solar system satellites such as Europa, Enceladus, and Titan will benefit strongly from investigations that can detect a wide range of organics in complex sample mixtures and ices, as well as determine the structure of selected molecules, to provide insight into their origin and evolution. At the same time, such missions are likely to be among the most highly constrained in mass and power resources, particularly those flown within the tightly focused Discovery and New Frontiers programs. Techniques requiring minimal or no sample manipulation or preparation may be needed to reduce complexity. Pulsed laser-based mass spectrometry may satisfy such requirements, with total instrument masses potentially less than 5 kg, particularly where analysis of higher-molecular weight, nonvolatile species is a priority objective. Prototype flight-compatible mass spectrometers under active development in our lab are based on direct ultraviolet Nd:YAG laser desorption and ionization (LDI) of solid samples under high vacuum. Prompt ions from a single few ns-duration laser pulse are accelerated into a compact time-of-flight mass spectrometer (TOF-MS). Both inorganic species including elements and oxides such as M_xO_y (M = Mg, Al, Cl, Ca, Fe; x, y = 1-4) from the mineral matrix as well as organics with molecular weights up to several kDa are readily detected over a range of laser intensities. To improve our ability to distinguish among peaks and patterns in the often-complex LDI spectra obtained from natural samples, we have recently begun systematically testing several critical instrument enhancements. First, by moving the common voltage bias of the ion flight tube and detector to a common negative potential, we are able to switch between positive and negative ion detection modes with only electrostatic switching. Inter-comparison of cation and anion spectra can provide highly diagnostic information on both inorganic (e.g., Na+ and K+ vs. Cl

  19. Radionuclide analysis in the soil of Kumaun Himalaya, India, using gamma ray spectrometry

    International Nuclear Information System (INIS)

    Ramola, R.C.; Prasad, Ganesh; Gusain, G.S.; Choubey, V.M.; Tosheva, Z.; Kies, A.

    2011-01-01

    Environmental release of low levels of radioactivity can occur as a consequence of normal radionuclides present in the earth's crust. We present here the results of a survey undertaken in 2003 on the radionuclide concentration in different rock formations in the eastern part of Kumaun Himalaya. The activity concentration and gamma-absorbed dose rates of the terrestrial radionuclides caused by 226 Ra, 232 Th and 40 K were determined in the soil samples collected from the eastern part of Kumaun Himalaya. The mean concentration of 238 U and 232 Th in the earth's crust varied from 0.5 to 5 ppm (6 to 60 Bq/kg) and 2 to 20 ppm (8 to 80 Bq/kg) respectively. The reported activity concentration for the different rock formations varied from 32.6 to 1305.5 Bq/kg for 238 U, 16.3 to 136.3 Bq/kg for 232 Th and 124.6 to 1758.0 Bq/kg for 40 K. The distribution of the radionuclides varied with rock type due to different chemical properties of the measured radionuclides and the rocks. The result shows that high activity levels were found in Saryu Formation consisting of augen-gneiss, granite interbedded with schists and flaggy quartzite. The total air-absorbed dose rate in air above 1 m height was calculated from the three radionuclides ( 226 Ra, 232 Th and 40 K), which varied from 39.1 to 226.8 nGy h -1 . The internal and external health-hazard indices were calculated based on the concentration of 226 Ra, 232 Th and 40 K. Strong positive correlations were observed between 235 U and 226 Ra, 232 Th and 226 Ra, 40 K and 232 Th as well as 40 K and 226 Ra. However, no significant correlation was observed between 238 U and 226 Ra because of radioactive disequilibrium between them. (author)

  20. Development of a gamma ray spectrometry software for neutron activation analysis using the open source concept

    International Nuclear Information System (INIS)

    Lucia, Silvio Rogerio de; Maihara, Vera Akiko; Menezes, Mario O. de

    2009-01-01

    In this work, a new software - SAANI (Instrumental Neutron Activation Analysis Software) was developed and used for gamma ray spectra analysis in the Neutron Activation Laboratory (LAN) of the Nuclear and Energetic Research Institute (IPEN-CNEN/SP). The software was developed to completely replace the old one - VISPECT. Besides the visual improvement in the user interface, the new software will allow the standardization of several procedures which are done nowadays in several different ways by each researcher, avoiding intermediate steps in the calculations. By using a modern programming language - Python, together with the graphical library Qt (by Trolltech), both multi-platform, the new software is able to run in Windows, Linux and other platforms. In addition to this, the new software has being designed to be extensible through plug-ins. In order to achieve the proposed initial scope, that is, completely replace the old software, SAANI has undergone several and different kinds of tests, using spectra from certified reference materials, standards and common spectra already analyzed by other software or that were used in international inter-comparisons. The results obtained by SAANI in all tests were considered very good. Some small discrepancies were found and after careful search and analysis, their source was identified as being an accuracy bug in the old software. Usability and robustness tests were conducted by installing SAANI in several laboratory computers and following them during daily utilization. The results of these tests also indicated that SAANI was ready to be used by all researchers in the LAN-IPEN. (author)

  1. In-situ high resolution particle sampling by large time sequence inertial spectrometry

    International Nuclear Information System (INIS)

    Prodi, V.; Belosi, F.

    1990-09-01

    In situ sampling is always preferred, when possible, because of the artifacts that can arise when the aerosol has to flow through long sampling lines. On the other hand, the amount of possible losses can be calculated with some confidence only when the size distribution can be measured with a sufficient precision and the losses are not too large. This makes it desirable to sample directly in the vicinity of the aerosol source or containment. High temperature sampling devices with a detailed aerodynamic separation are extremely useful to this purpose. Several measurements are possible with the inertial spectrometer (INSPEC), but not with cascade impactors or cyclones. INSPEC - INertial SPECtrometer - has been conceived to measure the size distribution of aerosols by separating the particles while airborne according to their size and collecting them on a filter. It consists of a channel of rectangular cross-section with a 90 degree bend. Clean air is drawn through the channel, with a thin aerosol sheath injected close to the inner wall. Due to the bend, the particles are separated according to their size, leaving the original streamline by a distance which is a function of particle inertia and resistance, i.e. of aerodynamic diameter. The filter collects all the particles of the same aerodynamic size at the same distance from the inlet, in a continuous distribution. INSPEC particle separation at high temperature (up to 800 C) has been tested with Zirconia particles as calibration aerosols. The feasibility study has been concerned with resolution and time sequence sampling capabilities under high temperature (700 C)

  2. Cation Exchange Efficiency Of Modified Bentonite Using In-Situ GAMMA Radiation Polymerization Of Acrylic Acid Or Acrylamide

    International Nuclear Information System (INIS)

    ISMAIL, S.A.; FALAZI, B.

    2009-01-01

    Modified bentonites as cation exchangers were prepared by treating raw bentonite with 3N NaOH at 95 0 C followed by in-situ polymerization using gamma irradiation as well as hydrogen peroxide initiation of acrylic acid or acrylamide in the matrix.Water swelling and acid capacity were determined and cation exchange capacity for Cu 2+ , Ni 2+ and Co 2+ was evaluated. It has been found that catiexchange capacity of treated bentonite was increased as result of formed polyacrylic acid and polyacrylamide in the matrix. In case of acrylic acid, the maximum cation exchange capacities of 3.5, 3.1 and 2.5 mg equivalent/g were determined for Cu 2+ , Ni 2+ and Co 2+ , respectively, and for acrylamide, the corresponding capacities were 2.9, 2.8 and 2.6 mg equivalent/g, respectively. Water swelling was found to be associated with holding large amounts of water, for instance, 49 g of water was sorbed per one gram of the sodium salt form of polyacrylic acid in bentonite matrix, in other words the degree of swelling in water achieved 4500%.

  3. Applied gamma ray spectrometry and remote sensing in delineation of nepheline syenites in rift tectonic settings

    Science.gov (United States)

    Chiwona, Annock Gabriel; Manning, David A. C.; Gaulton, Rachel; Cortes, Joaquin A.

    2017-04-01

    The United Nations (2016) observes that 'Neglected Development Minerals' including industrial minerals such as nepheline syenites have great potential for sustainable development, yet their exploitation has not been equally promoted like high value minerals. Nepheline syenites have great potential as alternative potassium (K) silicate fertiliser, as well as a source of Rare Earths. Demand for K fertiliser keeps rising by 3-3.5% annually (Jena et al., 2014) due to increased need to replace K removal from the soil (Sheldrick et al., 2002). The situation is most critical in Sub-Sahara Africa where nutrient loss due to intensive farming accounts to 22kg N, 2.5 kg P and 15 kg of K per hectare annually (Keeble, 2012). Ironically, Africa with 15% of global population, which is also expected to double by 2040 (Manning, 2015), uses only 1.5% of global K fertiliser. In this study, we use recently acquired countrywide airborne geophysical gamma ray data of Malawi (Bates & Mechennef, 2013) and satellite remote sensing data to identify nepheline syenites, suitable as sources of K silicate fertilizer, in rift tectonic settings. Initial focus was on the East African Rift System (EARS) starting with Malawi. Results from these two techniques are compared with X-ray fluorescence (XRF) geochemical analyses of sample collected from fieldwork in some potential areas of Malawi. With lessons from the Rochagem movement (Theodoro & Leonardos, 2006), identification of novel alternative potash sources in Africa will greatly benefit millions of farmers in developing countries, especially in Sub Sahara Africa where fertiliser costs are very high. Considering that high-resolution airborne geophysical data is not available in many African countries due to high costs associated with data acquisition campaigns, alternative and effective remote sensing approaches for delineating nepheline syenite rocks are necessary. References: [1] Bates M & Mechennef, F (2013) Data Acquisition Report, Sander

  4. 2015 In-Situ Gamma-Ray Assay of the West Cell Line in the 235-F Plutonium Fuel Form Facility

    Energy Technology Data Exchange (ETDEWEB)

    Brand, A. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Aucott, T. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); DiPrete, D. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-02-01

    In November and December 2015, scientists from SRNL took a series of in-situ gamma-ray measurements through the windows in front of Cells 6-9 on the west line of the PuFF facility using a shielded, 120% high-purity germanium detector. The detector efficiency was estimated using a combination of MCNP simulations and empirical measurements. Where possible, the distribution of the Pu-238 in the cells was determined using the Germanium Gamma-ray Imager (GeGI). This distribution was then fed into the MCNP model to quantify the Pu-238 in each cell. Data analysis was performed using three gamma rays emitted by Pu-238 (99.85 keV, 152.7 keV, and 766.4 keV) providing three independent estimates of the mass of Pu-238 holdup in each of the cells.

  5. Radiation levels in samples of dicalcium phosphate (DCP) and bovine and poultry rations by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Luz Filho, Isaias Venancio da; Scheibel, Viviane; Appoloni, Carlos Roberto

    2009-01-01

    The objective of the present work is to determine the radiation levels found in bovine rations and in the dicalcium phosphate (DCP) feed supplement. Knowledge of the radiation levels in samples of rations and DCP for cattle is important, because they are directly and indirectly-part of the human diet. In order to obtain this data, gamma-ray spectrometry technique was used, employing a HPGe detector of 66% of relative efficiency, with an energy resolution of 2.03 KeV for the 60 Co 1332.46 KeV line. The radioactive activity of the radionuclides 40 K, 137 Cs, 238 U, 232 Th and its respective decay series was measured. The accommodation recipient of the samples was a Marinelli beaker of 1 L. The 238 U series activities were calculated through 214 Pb and 214 Bi activities, and the 232 Th series' activity was calculated through the 228 Ac, 212 Pb, 212 Bi and 208 Tl values. The DCP samples and the rations measured in this work were produced in Londrina city, Brazil, in the second semester of 2007. Among the rations, the largest 40 K and 228 Ra activities were found in the ration sample for milk cattle, 402 ± 14 and 1.71 ± 0.10 Bq/kg, respectively. The ration for beef cattle yielded the largest activity for 226 Ra, 1.51 + 0.93 Bq/kg. In the DCP sample, the activities for the 238 U, 40 K and 232 Th were respectively 83 ± 26; 46.6 ± 2.8 and 7.79 ± 0.70 Bq/kg. The MDA values for 137 Cs varied from 0.037 to 0.29 Bq/kg. (author)

  6. In-situ gamma-ray assay of the east cell line in the 235-F Plutonium fuel form facility

    Energy Technology Data Exchange (ETDEWEB)

    Diprete, D. [Savannah River Site (SRS), Aiken, SC (United States)

    2015-08-21

    On September 17th -19th , 2013, scientists from SRNL took a series of in-situ gamma-ray measurements in the maintenance trench beneath Cells 1-5 on the east line of the PuFF facility using a well-collimated, high-purity germanium detector. The cell interiors were assayed along with the furnaces and storage coolers that protrude beneath the cells. The detector efficiency was estimated using a combination of MCNP simulations and empirical measurements. Data analysis was performed using three gamma-rays emitted by Pu-238 (99.85 keV, 152.7 keV, and 766.4 keV) providing three independent estimates of the mass of Pu-238 holdup in each of the cells. The weighted mean of these three results was used as the best estimate of Pu-238 holdup in the East Cell Line of PuFF. The results of the assay measurements are found in the table on the following page along with the results from the scoping assay performed in 2006. All uncertainties in this table (as well as the rest of the report) are reported at 1σ. Summing the assay results and treating MDAs as M238Pu= 0 ± MDA, the total holdup in the East Cell Line was 240 ± 40 grams. This result is 100 grams lower than the previous estimate, a 0.55σ difference. The uncertainty in the Pu-238 holdup is also reduced substantially relative to the 2006 scoping assay. However, the current assay results are in agreement with the 2006 scoping assay results due to the large uncertainty associated with the 2006 scoping assays. The current assay results support the conclusion that the 2006 results bound the Pu-238 mass in Cells 1-5. These results should be considered preliminary since additional measurements of the East Cell line are scheduled for 2017 and 2018. Those measurements will provide detailed information about the distribution of Pu-238 in the cells to be used to refine the results of the current assay.

  7. Insight into the in-cloud formation of oxalate based on in situ measurement by single particle mass spectrometry

    Science.gov (United States)

    Zhang, Guohua; Lin, Qinhao; Peng, Long; Yang, Yuxiang; Fu, Yuzhen; Bi, Xinhui; Li, Mei; Chen, Duohong; Chen, Jianxin; Cai, Zhang; Wang, Xinming; Peng, Ping'an; Sheng, Guoying; Zhou, Zhen

    2017-11-01

    While ground-based works suggest the significance of in-cloud production (or aqueous formation) to oxalate, direct evidence is rare. With the in situ measurements performed at a remote mountain site (1690 m above sea level) in southern China, we first reported the size-resolved mixing state of oxalate in the cloud droplet residual (cloud RES), the cloud interstitial (cloud INT), and ambient (cloud-free) particles by single particle mass spectrometry. The results support the growing evidence that in-cloud aqueous reactions promote the formation of oxalate, with ˜ 15 % of the cloud RES and cloud INT particles containing oxalate in contrast to only ˜ 5 % of the cloud-free particles. Furthermore, individual particle analysis provides unique insight into the formation of oxalate during in-cloud processing. Oxalate was predominantly (> 70 % in number) internally mixed with the aged biomass-burning particles, highlighting the impact of biomass burning on the formation of oxalate. In contrast, oxalate was underrepresented in aged elemental carbon particles, although they represented the largest fraction of the detected particles. It can be interpreted by the individual particle mixing state that the aged biomass-burning particles contained an abundance of organic components serving as precursors for oxalate. Through the analysis of the relationship between oxalate and organic acids (-45[HCO2]-, -59[CH3CO2]-, -71[C2H3CO2]-, -73[C2HO3]-), the results show that in-cloud aqueous reactions dramatically improved the conversion of organic acids to oxalate. The abundance of glyoxylate associated with the aged biomass-burning particles is a controlling factor for the in-cloud production of oxalate. Since only limited information on oxalate is available in the free troposphere, the results also provide an important reference for future understanding of the abundance, evolution, and climate impacts of oxalate.

  8. A study of self-attenuation correction for geological measures of Parana state, Brazil, granites with high resolution gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Ademar de O.; Pecequilo, Brigitte R.S., E-mail: aoferreira@ipen.b, E-mail: brigitte@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    In high resolution gamma-ray spectrometry correct determination of {sup 226}Ra, {sup 232}Th and {sup 40}K activities concentrations involve, beside accurate areas determinations, the use of precise efficiency calibration curves. As the efficiency calibration curve used for activities calculations was obtained with an aqueous standard multiradionuclides solution and the geological samples have apparent densities higher than the efficiency standard one, a correction of the efficiency curve is necessary. In this work, the self-attenuation correction factors were measured for sixteen geological samples from the Parana State Brazil crystalline shield, including lithotypes like rhyolite, granite, sienite and basalt, with apparent densities varying from 1.42 g cm-3 to 2.02 g cm-3. The self-attenuation factors were determined by the transmission technique and a high-resolution gamma-ray spectrometry facility, using {sup 60}Co, {sup 133}Ba, {sup 137}Cs and {sup 152}Eu punctual sources with well-known energies. For each density, a curve is fitted, allowing to correct the efficiency of the gamma transitions used in the determination of the {sup 226}Ra, {sup 232}Th and {sup 40}K activities concentrations. (author)

  9. A study of self-attenuation correction for geological measures of Parana state, Brazil, granites with high resolution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Ferreira, Ademar de O.; Pecequilo, Brigitte R.S.

    2011-01-01

    In high resolution gamma-ray spectrometry correct determination of 226 Ra, 232 Th and 40 K activities concentrations involve, beside accurate areas determinations, the use of precise efficiency calibration curves. As the efficiency calibration curve used for activities calculations was obtained with an aqueous standard multiradionuclides solution and the geological samples have apparent densities higher than the efficiency standard one, a correction of the efficiency curve is necessary. In this work, the self-attenuation correction factors were measured for sixteen geological samples from the Parana State Brazil crystalline shield, including lithotypes like rhyolite, granite, sienite and basalt, with apparent densities varying from 1.42 g cm-3 to 2.02 g cm-3. The self-attenuation factors were determined by the transmission technique and a high-resolution gamma-ray spectrometry facility, using 60 Co, 133 Ba, 137 Cs and 152 Eu punctual sources with well-known energies. For each density, a curve is fitted, allowing to correct the efficiency of the gamma transitions used in the determination of the 226 Ra, 232 Th and 40 K activities concentrations. (author)

  10. Spent BWR fuel characterisation combining a fork detector with gamma spectrometry. Report on Task JNT A 1071 FIN of the Finnish Support Programme to IAEA Safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Tiitta, A.; Hautamaeki, J. [VTT Chemical Technology, Espoo (Finland); Turunen, A. [Radiation and Nuclear Safety Authority, Helsinki (Finland); Arlt, R.; Arenas, Carrasco J.; Esmailpour-Kazerouni, K. [International Atomic Energy Agency, Vienna (Austria); Schwalbach, P. [Euratom Safeguards Office (United Kingdom)

    2001-02-01

    The LWR spent fuel assemblies have to be verified at the partial defect level before they become difficult to access. According to the IAEA's criteria the partial defect test for spent fuel should be able to detect if half or more of the fuel pins have been removed from an assembly and possibly replaced by dummies. Euratom applies similar criteria. Therefore a standard verification procedure needs to be developed using an appropriate combination of measurements and theoretical calculations. Two experiments with an 'upgraded' fork detector were performed at the TVO KPA Store in September and in December 1999. On the whole, 26 assemblies were measured. In the 'upgraded' fork detector the total neutron count and the gross gamma measurements are complemented with gamma spectroscopic measurement using an integrated measurement head. A cadmium-zinc-telluride (CZT) detector is placed on the same vertical level as the fission and ionisation chambers. This enables simultaneous gamma and neutron measurements at one location. In the upgraded fork model the fork prongs can also be removed and gamma spectrometric measurements can be done using only the CZT detector. This allows more versatile placement of the target fuel assembly allowing various kind of gamma spectroscopic scanning measurements. In this report a gamma spectroscopy based correction to the gross gamma data is introduced. This corrected gross gamma signal seems to describe more consistently the burnup of the assembly than the {sup 137}Cs intensity obtained by direct gamma spectrometry. Concerning the measured neutron data of assemblies with different enrichments, an enrichment correction method based on calculations made with the ORIGEN-S program is introduced in this report. In addition, the share of {sup 244}Cm neutrons of the total neutron source is derived from the results calculated with the PYVO program. These corrections to the neutron signal seem to improve the correlation of the

  11. Spent BWR fuel characterisation combining a fork detector with gamma spectrometry. Report on Task JNT A 1071 FIN of the Finnish Support Programme to IAEA Safeguards

    International Nuclear Information System (INIS)

    Tiitta, A.; Hautamaeki, J.; Turunen, A.; Arlt, R.; Arenas, Carrasco J.; Esmailpour-Kazerouni, K.; Schwalbach, P.

    2001-02-01

    The LWR spent fuel assemblies have to be verified at the partial defect level before they become difficult to access. According to the IAEA's criteria the partial defect test for spent fuel should be able to detect if half or more of the fuel pins have been removed from an assembly and possibly replaced by dummies. Euratom applies similar criteria. Therefore a standard verification procedure needs to be developed using an appropriate combination of measurements and theoretical calculations. Two experiments with an 'upgraded' fork detector were performed at the TVO KPA Store in September and in December 1999. On the whole, 26 assemblies were measured. In the 'upgraded' fork detector the total neutron count and the gross gamma measurements are complemented with gamma spectroscopic measurement using an integrated measurement head. A cadmium-zinc-telluride (CZT) detector is placed on the same vertical level as the fission and ionisation chambers. This enables simultaneous gamma and neutron measurements at one location. In the upgraded fork model the fork prongs can also be removed and gamma spectrometric measurements can be done using only the CZT detector. This allows more versatile placement of the target fuel assembly allowing various kind of gamma spectroscopic scanning measurements. In this report a gamma spectroscopy based correction to the gross gamma data is introduced. This corrected gross gamma signal seems to describe more consistently the burnup of the assembly than the 137 Cs intensity obtained by direct gamma spectrometry. Concerning the measured neutron data of assemblies with different enrichments, an enrichment correction method based on calculations made with the ORIGEN-S program is introduced in this report. In addition, the share of 244 Cm neutrons of the total neutron source is derived from the results calculated with the PYVO program. These corrections to the neutron signal seem to improve the correlation of the neutron signal to the burnup and to

  12. Comparative studies for determining U-235/U-238 relation in solutions of natural and depleted uranium using gamma spectrometry and neutron activation analysis

    International Nuclear Information System (INIS)

    Cassorla F, V.; Valle M, L.; Pena V, L.

    1988-01-01

    Two experimental methods were developed for determining U-235/U-238 ratio in uranium solutions. The isotopic was measured by high resolution ratio gamma-ray spectrometry (G.S.) and neutron activation analysis (N.A.A.). The precision obtained was similar for both methods, but better sensitivity was obtained by N.A.A. The accuracy in both cases was stablished by comparison with samples previously analyzed by mass spectrometry, the results were satisfactory for both techniques. Studies involving the influence of the nitric acid concentration on the isotopic ratio measurement, also were done. In addition, computer programs for faster data reduction were developped, in the case of N.A.A. (author)

  13. Recent advances in matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI) for in situ analysis of endogenous molecules in plants.

    Science.gov (United States)

    Qin, Liang; Zhang, Yawen; Liu, Yaqin; He, Huixin; Han, Manman; Li, Yanyan; Zeng, Maomao; Wang, Xiaodong

    2018-04-17

    Mass spectrometry imaging (MSI) as a label-free and powerful imaging technique enables in situ evaluation of a tissue metabolome and/or proteome, becoming increasingly popular in the detection of plant endogenous molecules. The characterization of structure and spatial information of endogenous molecules in plants are both very important aspects to better understand the physiological mechanism of plant organism. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is a commonly-used tissue imaging technique, which requires matrix to assist in situ detection of a variety of molecules on the surface of a tissue section. In previous studies, MALDI-MSI was mostly used for the detection of molecules from animal tissue sections, compared to plant samples due to cell structural limitations, such as plant cuticles, epicuticular waxes, and cell walls. Despite the enormous progress that has been made in tissue imaging, there is still a challenge for MALDI-MSI suitable for the imaging of endogenous compounds in plants. This review summarises the recent advances in MALDI-MSI, focusing on the application of in situ detection of endogenous molecules in different plant organs, i.e. root, stem, leaf, flower, fruit, and seed. Further improvements on instrumentation sensitivity, matrix selection, image processing and sample preparation will expand the application of MALDI-MSI in plant research. Copyright © 2018 John Wiley & Sons, Ltd.

  14. Study of radionuclide and element characterization of Angola marine sediment using low background gamma spectrometry and instrumental neutron activation analysis techniques

    International Nuclear Information System (INIS)

    Teixeira, M.C.P.; Vuong Huu Tan; Truong Y; Ho Manh Dung; Le Nhu Sieu; Cao Dong Vu; Nguyen Thanh Binh

    2007-01-01

    The concentrations of radionuclides and chemical elements in Angola marine sediment samples were determined by using low background gamma (LBG) spectrometry and instrumental neutron activation analysis (INAA). The combination of radionuclide and elemental concentration values yielded synergy in the validation of analytical data and identification of sediment sources modeled by multivariate factor analysis. Varimax rotation factor analysis based on the elemental concentrations revealed five sources contributed to the sediment composition, i.e. crustal, sea-salt, industrial, coal-related and Se-related sources. (author)

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  16. Some considerations on the use of gamma spectrometry for Kr-85 determination at gaseous effluents in the nuclear industry and environmental samples; Estudio sobre la aplicacin de la espectrometria gamma en la medida del Kr-8 5 ambiental y en efluentes gaseosos de la industria nuclear

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-07-01

    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{sup -}4 {mu}Ci 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.

  17. Insight into the in-cloud formation of oxalate based on in situ measurement by single particle mass spectrometry

    Directory of Open Access Journals (Sweden)

    G. Zhang

    2017-11-01

    Full Text Available While ground-based works suggest the significance of in-cloud production (or aqueous formation to oxalate, direct evidence is rare. With the in situ measurements performed at a remote mountain site (1690 m above sea level in southern China, we first reported the size-resolved mixing state of oxalate in the cloud droplet residual (cloud RES, the cloud interstitial (cloud INT, and ambient (cloud-free particles by single particle mass spectrometry. The results support the growing evidence that in-cloud aqueous reactions promote the formation of oxalate, with  ∼  15 % of the cloud RES and cloud INT particles containing oxalate in contrast to only  ∼  5 % of the cloud-free particles. Furthermore, individual particle analysis provides unique insight into the formation of oxalate during in-cloud processing. Oxalate was predominantly (> 70 % in number internally mixed with the aged biomass-burning particles, highlighting the impact of biomass burning on the formation of oxalate. In contrast, oxalate was underrepresented in aged elemental carbon particles, although they represented the largest fraction of the detected particles. It can be interpreted by the individual particle mixing state that the aged biomass-burning particles contained an abundance of organic components serving as precursors for oxalate. Through the analysis of the relationship between oxalate and organic acids (−45[HCO2]−, −59[CH3CO2]−, −71[C2H3CO2]−, −73[C2HO3]−, the results show that in-cloud aqueous reactions dramatically improved the conversion of organic acids to oxalate. The abundance of glyoxylate associated with the aged biomass-burning particles is a controlling factor for the in-cloud production of oxalate. Since only limited information on oxalate is available in the free troposphere, the results also provide an important reference for future understanding of the abundance, evolution, and climate impacts of oxalate.

  18. In situ-observation of the vertical motion of soil waters by means of deuterated water using the gamma/neutron method: Laboratory and field

    International Nuclear Information System (INIS)

    Moutonnet, P.; Couchat, P.; Brissaud, F.; Puard, M.; Pappalardo, A.

    1978-01-01

    In order to study water movements in the field, the gamma/neutron method for measuring deuterated water was investigated. A laboratory device is presented which supplies measurements on 5 ml soil solution samples. A probe for in situ experiments is studied in all its performances: Background, calibration (count rate versus volumetric deuterated water content) and resolution. A dispersive transport of D 2 O pulses on soil column is presented and checked with a numerical simulation model. Then simultaneous measurement of soil water content and D 2 O concentration by neutron moisture gauge and gamma/neutron probe enable us to interpret the evolution of D 2 O pulse with an experimental field irrigation. (orig.) [de

  19. Latent transforming growth factor beta1 activation in situ: quantitative and functional evidence after low-dose gamma-irradiation

    Science.gov (United States)

    Ehrhart, E. J.; Segarini, P.; Tsang, M. L.; Carroll, A. G.; Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator)

    1997-01-01

    The biological activity of transforming growth factor beta1 (TGF-beta) is controlled by its secretion as a latent complex in which it is noncovalently associated with latency-associated peptide (LAP). Activation is the extracellular process in which TGF-beta is released from LAP, and is considered to be a primary regulatory control. We recently reported rapid and persistent changes in TGF-beta immunoreactivity in conjunction with extracellular matrix remodeling in gamma-irradiated mouse mammary gland. Our hypothesis is that these specific changes in immunoreactivity are indicative of latent TGF-beta activation. In the present study, we determined the radiation dose response and tested whether a functional relationship exists between radiation-induced TGF-beta and collagen type III remodeling. After radiation exposures as low as 0.1 Gy, we detected increased TGF-beta immunoreactivity in the mammary epithelium concomitant with decreased LAP immunostaining, which are events consistent with activation. Quantitative image analysis demonstrated a significant (P=0.0005) response at 0.1 Gy without an apparent threshold and a linear dose response to 5 Gy. However, in the adipose stroma, loss of LAP demonstrated a qualitative threshold at 0.5 Gy. Loss of LAP paralleled induction of collagen III immunoreactivity in this tissue compartment. We tested whether TGF-beta mediates collagen III expression by treating animals with TGF-beta panspecific monoclonal antibody, 1D11.16, administered i.p. shortly before irradiation. Radiation-induced collagen III staining in the adipose stroma was blocked in an antibody dose-dependent manner, which persisted through 7 days postirradiation. RNase protection assay revealed that radiation-induced elevation of total gland collagen III mRNA was also blocked by neutralizing antibody treatment. These data provide functional confirmation of the hypothesis that radiation exposure leads to latent TGF-beta activation, support our interpretation of the

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-03

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

  1. Low-resolution gamma-ray spectrometry for an information barrier based on a multi-criteria template-matching approach

    Energy Technology Data Exchange (ETDEWEB)

    Göttsche, Malte; Schirm, Janet; Glaser, Alexander

    2016-12-21

    Gamma-ray spectrometry has been successfully employed to identify unique items containing special nuclear materials. Template information barriers have been developed in the past to confirm items as warheads by comparing their gamma signature to the signature of true warheads. Their development has, however, not been fully transparent, and they may not be sensitive to some relevant evasion scenarios. We develop a fully open template information barrier concept, based on low-resolution measurements, which, by design, reduces the extent of revealed sensitive information. The concept is based on three signatures of an item to be compared to a recorded template. The similarity of the spectrum is assessed by a modification of the Kolmogorov–Smirnov test to confirm the isotopic composition. The total gamma count rate must agree with the template as a measure of the projected surface of the object. In order to detect the diversion of fissile material from the interior of an item, a polyethylene mask is placed in front of the detector. Neutrons from spontaneous and induced fission events in the item produce 2.223 MeV gamma rays from neutron capture by hydrogen-1 in the mask. This peak is detected and its intensity scales with the item's fissile mass. The analysis based on MCNP Monte Carlo simulations of various plutonium configurations suggests that this concept can distinguish a valid item from a variety of invalid ones. The concept intentionally avoids any assumptions about specific spectral features, such as looking for specific gamma peaks of specific isotopes, thereby facilitating a fully unclassified discussion. By making all aspects public and allowing interested participants to contribute to the development and benchmarking, we enable a more open and inclusive discourse on this matter.

  2. Intercomparison measurements of surface soil contamination with in-situ gamma ray spectrometry. Pt.1. Artificial radionuclides

    International Nuclear Information System (INIS)

    Winkelmann, I.

    1994-01-01

    This intercomparison program was performed by the Federal Office of Radiation Protection in October 1993. It includes seven laboratory teams from five countries and is applied on a pasture in southern Germany having an undisturbed soil profile. The location was chosen because of its relatively high 137 Cs-soil contamination caused by the Chernobyl accident - up to 50 kBq/m 2 . The deposition of 134 Cs and 137 Cs was determined. The comparison demonstrated a good agreement between results from different labs. Additionally, the dose rate at all marked locations was measured and compared to the dose rate of individual radionuclides calculated from the measured spectra. A relatively good agreement was obtained. It is shown that the main contribution to the total dose rate of 70 nSv/h is made by 137 Cs with a value of 5 nSv/h. 4 figs., 2 tabs., 3 refs. (orig.)

  3. 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 ur...... Nordic and European countries participated in the intercomparison. Extraordinary variation between the results reported by different laboratories were revealed for some radionuclides indicating the need of future intercomparisons especially in the case of natural water samples.......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...

  4. Calculation spreadsheet for uncertainty estimation of measurement results in gamma-ray spectrometry and its validation for quality assurance purpose

    International Nuclear Information System (INIS)

    Ceccatelli, Alessia; Dybdal, Ashild; Fajgelj, Ales; Pitois, Aurelien

    2017-01-01

    An Excel calculation spreadsheet has been developed to estimate the uncertainty of measurement results in γ-ray spectrometry. It considers all relevant uncertainty components and calculates the combined standard uncertainty of the measurement result. The calculation spreadsheet has been validated using two independent open access software and is available for download free of charge. It provides a simple and easy-to-use template for estimating the uncertainty of γ-ray spectrometry measurement results and supports the radioanalytical laboratories seeking accreditation for their measurements using γ-ray spectrometry. - Highlights: • A calculation spreadsheet for estimation of measurement result uncertainty in γ-ray spectrometry was developed. • Two independent software were used to validate the calculation spreadsheet. • The calculation spreadsheet is available for download free of charge. • The work presented supports quality assurance of radioanalytical laboratories.

  5. Determination of activity by gamma spectrometry of radionuclides present in drums of residues generated in nuclear centrals; Determinacion de actividad por espectrometria gamma de radionucleidos presentes en tambores de residuos generados en centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, J.C.; Fernandez, J. [Autoridad Regulatoria Nuclear, Av. Del Libertador 8250, Ciudad Autonoma de Buenos Aires (Argentina)]. e-mail: jaguiar@cae.arn.gov.ar

    2006-07-01

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

  6. Spectral interference corrections for the measurement of (238)U in materials rich in thorium by a high resolution gamma-ray spectrometry.

    Science.gov (United States)

    Yücel, H; Solmaz, A N; Köse, E; Bor, D

    2009-11-01

    In this study, the spectral interferences are investigated for the analytical peaks at 63.3 keV of (234)Th and 1001.0 keV of (234m)Pa, which are often used in the measurement of (238)U activity by the gamma-ray spectrometry. The correction methods are suggested to estimate the net peak areas of the gamma-rays overlapping the analytical peaks, due to the contribution of (232)Th that may not be negligible in materials rich in natural thorium. The activity results for the certified reference materials (CRMs) containing U and Th were measured with a well type Ge detector. The self-absorption and true coincidence-summing (TCS) effects were also taken into account in the measurements. It is found that ignoring the contributions of the interference gamma-rays of (232)Th and (235)U to the mixed peak at 63.3 keV of (234)Th ((238)U) leads to the remarkably large systematic influence of 0.8-122% in the measured (238)U activity, but in case of ignoring the contribution of (232)Th via the interference gamma-ray at 1000.7 keV of (228)Ac to the mixed peak at 1001 keV of (234m)Pa ((238)U) results in relatively smaller systematic influence of 0.05-3%, depending on thorium contents in the samples. The present results showed that the necessary correction for the spectral interferences besides self-absorption and TCS effects is also very important to obtain more accurate (238)U activity results. Additionally, if one ignores the contribution of (232)Th to both (238)U and (40)K activities in materials, the maximum systematic influence on the effective radiation dose is estimated to be ~6% and ~1% via the analytical peaks at 63.3 and 1001 keV for measurement of the (238)U activity, respectively.

  7. Trace analysis of chlorophenols in river water samples by stir bar sorptive extraction with in situ derivatization and thermal desorption-gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kawaguchi, M.; Ishii, Y.; Okanouchi, N.; Sakui, N.; Ito, R.; Inoue, K.; Nakazawa, H. [Hoshi Univ., Tokyo (Japan). Dept. of Analytical Chemistry, Faculty of Pharmaceutical Sciences; Saito, K. [Saitama Institute of Public Health, Saitama (Japan). Dioxin Research Group

    2004-09-15

    Many analytical methods for the determination of chlorophenols in water samples have been reported including gas chromatography-mass spectrometry (GC-MS). However, GC-MS was initially used for the determination of phenol compounds even though derivatization was required. The derivatization leads to sharper peaks and hence to better separation and higher sensitivity for the phenols. However, the derivatization faces the risk of contamination and hence an overestimation of chlorophenols concentration. In order to overcome these problems, in situ derivatization has been developed, which involves the simple addition of a reagent to a liquid sample. Recently, a new sorptive extraction technique that uses a stir bar coated with polydimethylsiloxane (PDMS) was developed. The technique is known as stir bar sorptive extraction (SBSE). We already reported that determination of 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in river water4 and body fluid samples by using SBSE. In addition, SBSE with in situ derivatization has been successfully used in the determination of bisphenol A (BPA) in human body fluid samples6 and phenolic xenoestrogens in river water samples. The aim of this study is to determine trace amounts of chlorophenols in water samples by SBSE with in situ derivatization, followed by thermal desorption (TD)-GC-MS. The developed method was applied to determination of chlorophenols in river water samples.

  8. Evaluation of 210Pb air activity concentration by direct gamma-ray spectrometry of air particulate samplings

    International Nuclear Information System (INIS)

    Rizzo, S.; Tomarchio, E.

    2007-01-01

    Main measurement techniques adopted to evaluate 210 PB air activity concentration differ in analysis and sample preparation methods. Some of them involved complex chemical processes or decay product detection (for example 210 Po), with a long decay time period between sampling and experimental measurement. The availability of a low-background gamma-ray spectrometric system, suitable to measure low-energy gamma radiations, allows the evaluation of 210 PB air activity concentration by direct gamma countings of particulate samplings after a short time period from the end of the sampling. The measurement procedure described in this work consists in the following steps: o Sampling of air particulate and recording of sampling data; o Fast reduction of the sample to measurement geometry; o Gamma-ray spectrometric measurement (or a series of measurements) after a minimum decay time period from the end of sampling; o A new gamma-ray spectrometric measurement, with reference to 46.5 keV gamma emission of 210 PB, after a few days from the sampling; o Comparison with a model to evaluate the 210 PB activity percentage produced by decay of short-lived radon daughters on the filter matrix during and after the sampling; o Determination of 210 PB net activity and derived air concentration. Experimental tests have allowed obtaining a range of 2†10 per cent for 210 PB activity percentage on a filter due to decay of short-lived radon daughters, with higher values when 210 PB air activity concentration is very low. All the measurements resulted above detection limit, even in the case of a short sampling time period. A statistical improvement on 210 PB activity can be obtained with a longer sampling time period, without any modification on the procedure and results. (Author)

  9. Mapping the spatial distribution and activity of 226Ra at legacy sites through Machine Learning interpretation of gamma-ray spectrometry data

    International Nuclear Information System (INIS)

    Varley, Adam; Tyler, Andrew; Smith, Leslie; Dale, Paul; Davies, Mike

    2016-01-01

    Radium ( 226 Ra) contamination derived from military, industrial, and pharmaceutical products can be found at a number of historical sites across the world posing a risk to human health. The analysis of spectral data derived using gamma-ray spectrometry can offer a powerful tool to rapidly estimate and map the activity, depth, and lateral distribution of 226 Ra contamination covering an extensive area. Subsequently, reliable risk assessments can be developed for individual sites in a fraction of the timeframe compared to traditional labour-intensive sampling techniques: for example soil coring. However, local heterogeneity of the natural background, statistical counting uncertainty, and non-linear source response are confounding problems associated with gamma-ray spectral analysis. This is particularly challenging, when attempting to deal with enhanced concentrations of a naturally occurring radionuclide such as 226 Ra. As a result, conventional surveys tend to attribute the highest activities to the largest total signal received by a detector (Gross counts): an assumption that tends to neglect higher activities at depth. To overcome these limitations, a methodology was developed making use of Monte Carlo simulations, Principal Component Analysis and Machine Learning based algorithms to derive depth and activity estimates for 226 Ra contamination. The approach was applied on spectra taken using two gamma-ray detectors (Lanthanum Bromide and Sodium Iodide), with the aim of identifying an optimised combination of detector and spectral processing routine. It was confirmed that, through a combination of Neural Networks and Lanthanum Bromide, the most accurate depth and activity estimates could be found. The advantage of the method was demonstrated by mapping depth and activity estimates at a case study site in Scotland. There the method identified significantly higher activity (< 3 Bq g −1 ) occurring at depth (> 0.4 m), that conventional gross counting algorithms

  10. Mapping the spatial distribution and activity of {sup 226}Ra at legacy sites through Machine Learning interpretation of gamma-ray spectrometry data

    Energy Technology Data Exchange (ETDEWEB)

    Varley, Adam, E-mail: a.l.varley@stir.ac.uk [Department of Biological and Environmental Sciences, University of Stirling, Stirling FK9 4LA (United Kingdom); Tyler, Andrew [Department of Biological and Environmental Sciences, University of Stirling, Stirling FK9 4LA (United Kingdom); Smith, Leslie [Department of Computing Science and Mathematics, University of Stirling, Stirling FK9 4LA (United Kingdom); Dale, Paul [Scottish Environmental Protection Agency, Radioactive Substances, Strathallan House, Castle Business Park, Stirling FK9 4TZ (United Kingdom); Davies, Mike [Nuvia Limited, The Library, Eight Street, Harwell Oxford, Didcot, Oxfordshire OX11 0RL (United Kingdom)

    2016-03-01

    Radium ({sup 226}Ra) contamination derived from military, industrial, and pharmaceutical products can be found at a number of historical sites across the world posing a risk to human health. The analysis of spectral data derived using gamma-ray spectrometry can offer a powerful tool to rapidly estimate and map the activity, depth, and lateral distribution of {sup 226}Ra contamination covering an extensive area. Subsequently, reliable risk assessments can be developed for individual sites in a fraction of the timeframe compared to traditional labour-intensive sampling techniques: for example soil coring. However, local heterogeneity of the natural background, statistical counting uncertainty, and non-linear source response are confounding problems associated with gamma-ray spectral analysis. This is particularly challenging, when attempting to deal with enhanced concentrations of a naturally occurring radionuclide such as {sup 226}Ra. As a result, conventional surveys tend to attribute the highest activities to the largest total signal received by a detector (Gross counts): an assumption that tends to neglect higher activities at depth. To overcome these limitations, a methodology was developed making use of Monte Carlo simulations, Principal Component Analysis and Machine Learning based algorithms to derive depth and activity estimates for {sup 226}Ra contamination. The approach was applied on spectra taken using two gamma-ray detectors (Lanthanum Bromide and Sodium Iodide), with the aim of identifying an optimised combination of detector and spectral processing routine. It was confirmed that, through a combination of Neural Networks and Lanthanum Bromide, the most accurate depth and activity estimates could be found. The advantage of the method was demonstrated by mapping depth and activity estimates at a case study site in Scotland. There the method identified significantly higher activity (< 3 Bq g{sup −1}) occurring at depth (> 0.4 m), that conventional gross

  11. Measurements of natural gamma radiation in beach sediments of north east coast of Tamilnadu, India by gamma ray spectrometry with multivariate statistical approach

    Directory of Open Access Journals (Sweden)

    M. SureshGandhi

    2014-01-01

    Full Text Available The distribution of natural gamma ray emitting 238U, 232Th and 40K radionuclides in beach sediments along north east coast of Tamilnadu, India has been carried out using a NaI(Tl gamma ray spectrometric technique. The total average concentrations of radionuclides 238U, 232Th, and 40K were 35.12, 713.16, and 349.60 Bq kg−1, respectively. Correlations made among these radionuclides prove the existence of secular equilibrium in the investigated sediments. The total average absorbed dose rate in the study areas is found to be 504.75 nGyh−1, whereas the annual effective dose rate has an average value of 0.62 mSvy−1. The mean activity concentrations of measured radionuclides were compared with other literature values. The ratios between the detected radioisotopes have been calculated for spatial distribution of natural radionuclides in studied area. Also the radiological hazard of the natural radionuclides content, radium equivalent activity, external hazard index of the sediment samples in the area under consideration were calculated. Multivariate Statistical analyses (Pearson Correlation, Cluster and Factor analysis were carried out between the parameters obtained from radioactivity to know the existing relations.

  12. Quantitative analysis of the fission product distribution in a damaged fuel assembly using gamma-spectrometry and computed tomography for the Phébus FPT3 test

    International Nuclear Information System (INIS)

    Biard, B.

    2013-01-01

    Highlights: • The FP quantitative distribution in the fuel bundle is measured by gamma-spectrometry. • The FP location is obtained with emission tomograms and other experiment results. • X-ray tomograms provide the material and density mapping of the degraded bundle. • The self-attenuation may then be computed for each isotope at its key line energy. • Results are consistent with other FPT3 measurements, with acceptable uncertainties. -- Abstract: The international Phébus FP programme, initiated in 1988 by the French “Institut de Radioprotection et de Sûreté Nucléaire” (IRSN), in cooperation with the European Commission (EC) and with financial support from USNRC, Canada, PSI/HSK (Switzerland), Japan and Korea, was aimed at studying severe accident phenomena: the fuel degradation, the release of fission products (FPs) and their transport through the reactor coolant system to the containment building. The FPT3 test, conducted in 2004, was the last of the five light water reactor core meltdown accident tests performed on irradiated fuel rods. After the experiment, the test device was recovered and analysed through a full set of non-destructive examinations performed over the fuel bundle zone, including gamma-scanning, gamma emission tomography, X-ray radiography and X-ray transmission tomography. The gamma-scanning was specifically devoted to the location, identification and amount quantification of the FPs remaining in the bundle. Since the fuel bundle became highly degraded during the experiment, the geometry was different at each level examined, and did not correspond to the well-known initial state. The self-attenuation of the test device and consequently the efficiency correction could then not be estimated by classical means that need to know the geometry of the object. Using the results of the other non-destructive examinations, specific computational tools and methods have therefore been developed to compute the self-attenuation of the bundle

  13. Stratigraphic variation of complex impurities in platform limestones and possible significance of atmospheric dust: a study with emphasis on gamma-ray spectrometry and magnetic susceptibility outcrop logging (Eifelian-Frasnian, Moravia, Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Hladil, Jindřich; Geršl, M.; Strnad, L.; Frána, Jaroslav; Langrová, Anna; Spišiak, J.

    2006-01-01

    Roč. 95, č. 4 (2006), s. 703-723 ISSN 1437-3254 Institutional research plan: CEZ:AV0Z30130516; CEZ:AV0Z10480505 Keywords : complex impurities * platform limestones * gamma-ray spectrometry Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.905, year: 2006

  14. Precision measurement of radioactivity in gamma-rays spectrometry using two HPGe detectors (BEGe-6530 and GC0818-7600SL models comparison techniques: Application to the soil measurement

    Directory of Open Access Journals (Sweden)

    Guembou Shouop Cebastien Joel

    2017-01-01

    • Proved that the activity concentration determination in gamma spectrometry depended on the energy range emitted by a radionuclide. This study showed that the standard deviation measurement was less important to the result realized with BEGe-6530 HPGe model. Our findings were demonstrated that the results of the Broad Energy Germanium detector were more reliable.

  15. Standard test method for nondestructive analysis of special nuclear materials in homogeneous solutions by Gamma-Ray spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers the determination of the concentration of gamma-ray emitting special nuclear materials dissolved in homogeneous solutions. The test method corrects for gamma-ray attenuation by the solution and its container by measurement of the transmission of a beam of gamma rays from an external source (Refs. (1), (2), and (3)). 1.2 Two solution geometries, slab and cylinder, are considered. The solution container that determines the geometry may be either a removable or a fixed geometry container. This test method is limited to solution containers having walls or a top and bottom of equal transmission through which the gamma rays from the external transmission correction source must pass. 1.3 This test method is typically applied to radionuclide concentrations ranging from a few milligrams per litre to several hundred grams per litre. The assay range will be a function of the specific activity of the nuclide of interest, the physical characteristics of the solution container, counting equip...

  16. Simultaneous determination of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry INa(Ti), in solid samples

    International Nuclear Information System (INIS)

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

    1991-01-01

    A method has been developed to determine activities of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry. The measurement system has been calibrated using standards specially prepared at the laboratory. It is necessary to assume secular equilibrium in the samples, between Ra-226 and Th-232 and its daughters nuclides, and between U-238 and its immediate daughter Th-234, as the photo peaks measured are those of the daughters. The results obtained indicate that this method can of ter replace the radiochemical techniques used to measure activities in this type of sample. The method has been successfully used to determine these natural isotopes in samples from uranium mills. (Author) 9 refs

  17. High energy resolution and high count rate gamma spectrometry measurement of primary coolant of generation 4 sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Coulon, R.

    2010-01-01

    Sodium-cooled Fast Reactors are under development for the fourth generation of nuclear reactor. Breeders reactors could gives solutions for the need of energy and the preservation of uranium resources. An other purpose is the radioactive wastes production reduction by transmutation and the control of non-proliferation using a closed-cycle. These thesis shows safety and profit advantages that could be obtained by a new generation of gamma spectrometry system for SFR. Now, the high count rate abilities, allow us to study new methods of accurate power measurement and fast clad failure detection. Simulations have been done and an experimental test has been performed at the French Phenix SFR of the CEA Marcoule showing promising results for these new measurements. (author) [fr

  18. Low-energy X-ray and gamma spectrometry using silicon photodiodes; Espectrometria de raios X e gama de baixa energia utilizando fotodiodos de silicio

    Energy Technology Data Exchange (ETDEWEB)

    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{sup 2} and 0,25 cm{sup 2}, thickness of the depletion ranging from 100 to 200 {mu}m 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 {sup 241} Am, {sup 109} Cd, {sup 57} Co and {sup 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)

  19. A sapphire tube atomizer for on-line atomization and in situ collection of bismuthine for atomic absorption spectrometry

    Czech Academy of Sciences Publication Activity Database

    Musil, Stanislav; Dědina, Jiří

    2013-01-01

    Roč. 28, č. 4 (2013), s. 593-600 ISSN 0267-9477 Institutional support: RVO:68081715 Keywords : hydride generation * sapphire tube atomizer * in situ collection Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.396, year: 2013

  20. Determination of the Concentration of Radioactive Nuclides of Surface Soils of some Hadhramout's Valleys in Yemen Using Gamma-Ray Spectrometry

    International Nuclear Information System (INIS)

    Bazohair, A. O.; Bayashoot, A. K.; AL-Shamy, A. A.

    2004-01-01

    In this research five surface soil samples have been taken from some Hadhramout's valleys in Yemen (Khrid , Arf , Huwayrah , Buwaish, Khirba ) in the years from (1999) to (2002) and analyzed using gamma-ray spectrometry. The spectra of samples were measured using multichannel analyzer (MCA) that was connected with measurement system for this purpose.A high purity germanium(Hp Ge) detector with resolution of (2.11 keV) at gamma-line(1332 keV) of radioactive source(Co-60) used for detecting ( U 238 , Th 232 , K 40 , Cs 137 ) in the samples. The results showed that the average concentration of radioactive nuclides in the samples of uranium ranged from(37.56 Bq/Kg) to(46.58 Bq/Kg) and for thorium ranged from(37.93 Bq/Kg) to(47.28 Bq/Kg) and for potassium ranged from(347.57 Bq/Kg) to(850.10 Bq/Kg) and for cesium ranged from(6.94 Bq/Kg) to(15.86 Bq/Kg) and the measured precision of samples ranged from(4.71%) to (9.23%). (authors)

  1. Radioactivity measurements in soils surrounding four coal-fired power plants in Serbia by gamma-ray spectrometry and estimated dose

    Directory of Open Access Journals (Sweden)

    Vukašinović Ivana Ž.

    2014-01-01

    Full Text Available The study of spatial distribution of activity concentration of 238U, 226Ra, 210Pb, 232Th, 40K, and 137Cs radionuclides in the surface soil samples (n = 42 collected in the vicinity of four coal-fired power plants in Serbia is presented. Radioactivity measurements in soils performed by gamma-ray spectrometry showed values [Bqkg-1] in the range: 15-117 for 238U, 21-115 for 226Ra, 33-65 for 210Pb, 20-69 for 232Th, 324-736 for 40K, and 2-59 for 137Cs. Surface soil radio-activity that could have resulted from deposition of radionuclides from airborne discharges or resuspension of ash from disposal sites showed no enhanced levels. It was found that variation of soil textural properties, pH values, and carbonate content influenced activity levels of natural radionuclides while radiocesium activities were associated with soil organic matter content. Modification of some soil properties was observed in the immediate vicinity (<1 km of power plants where the soil was more alkaline with coarser particles (0.2-0.05 mm and carbonates accumulated. Calculated average values of the absorbed gamma dose rate and annual external effective dose originating from the terrestrial radionuclides were 69.4 nGy/h and 0.085 mSv, respectively. [Projekat Ministarstva nauke Republike Srbije, br. 4007: Studying climate change and its influence on the environment: impacts, adaptation and mitigation

  2. Radon potential mapping of the Tralee-Castleisland and Cavan areas (Ireland) based on airborne gamma-ray spectrometry and geology.

    Science.gov (United States)

    Appleton, J D; Doyle, E; Fenton, D; Organo, C

    2011-06-01

    The probability of homes in Ireland having high indoor radon concentrations is estimated on the basis of known in-house radon measurements averaged over 10 km × 10 km grid squares. The scope for using airborne gamma-ray spectrometer data for the Tralee-Castleisland area of county Kerry and county Cavan to predict the radon potential (RP) in two distinct areas of Ireland is evaluated in this study. Airborne data are compared statistically with in-house radon measurements in conjunction with geological and ground permeability data to establish linear regression models and produce radon potential maps. The best agreement between the percentage of dwellings exceeding the reference level (RL) for radon concentrations in Ireland (% > RL), estimated from indoor radon data, and modelled RP in the Tralee-Castleisland area is produced using models based on airborne gamma-ray spectrometry equivalent uranium (eU) and ground permeability data. Good agreement was obtained between the % > RL from indoor radon data and RP estimated from eU data in the Cavan area using terrain specific models. In both areas, RP maps derived from eU data are spatially more detailed than the published 10 km grid map. The results show the potential for using airborne radiometric data for producing RP maps.

  3. Nondestructive and quantitative characterization of TRU and LLW mixed-waste using active and passive gamma-ray spectrometry and computed tomography

    International Nuclear Information System (INIS)

    Camp, D.C.; Martz, H.E.

    1991-01-01

    The technology being proposed by LLNL is an Active and Passive Computed Tomography (A ampersand P CT) Drum Scanner for contact-handled (CH) wastes. It combines the advantages offered by two well-developed nondestructive assay technologies: gamma-ray spectrometry and computed tomography (CT). Coupled together, these two technologies offer to nondestructively and quantitatively characterize mixed- wastes forms. Gamma-ray spectroscopy uses one or more external radiation detectors to passively and nondestructively measure the energy spectrum emitted from a closed container. From the resulting spectrum one can identify most radioactivities detected, be they transuranic isotopes, mixed-fission products, activation products or environmental radioactivities. Spectral libraries exist at LLNL for all four. Active (A) or transmission CT is a well-developed, nondestructive medical and industrial technique that uses an external-radiation beam to map regions of varying attenuation within a container. Passive (P) or emission CT is a technique mainly developed for medical application, e.g., single-photon emission CT. Nondestructive industrial uses of PCT are under development and just coming into use. This report discuses work on the A ampersand P CT Drum Scanner at LLNL

  4. Nondestructive and quantitative characterization of TRU and LLW mixed-waste using active and passive gamma-ray spectrometry and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Camp, D.C.; Martz, H.E.

    1991-11-12

    The technology being proposed by LLNL is an Active and Passive Computed Tomography (A P CT) Drum Scanner for contact-handled (CH) wastes. It combines the advantages offered by two well-developed nondestructive assay technologies: gamma-ray spectrometry and computed tomography (CT). Coupled together, these two technologies offer to nondestructively and quantitatively characterize mixed- wastes forms. Gamma-ray spectroscopy uses one or more external radiation detectors to passively and nondestructively measure the energy spectrum emitted from a closed container. From the resulting spectrum one can identify most radioactivities detected, be they transuranic isotopes, mixed-fission products, activation products or environmental radioactivities. Spectral libraries exist at LLNL for all four. Active (A) or transmission CT is a well-developed, nondestructive medical and industrial technique that uses an external-radiation beam to map regions of varying attenuation within a container. Passive (P) or emission CT is a technique mainly developed for medical application, e.g., single-photon emission CT. Nondestructive industrial uses of PCT are under development and just coming into use. This report discuses work on the A P CT Drum Scanner at LLNL.

  5. {sup 129}I determination by direct Ge gamma-X spectrometry and its application to the concentration variation in two seaweed species

    Energy Technology Data Exchange (ETDEWEB)

    Barker, E.; Bouisset, P. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Environmental Radioactivity Measurement Lab., 91 - Orsay (France); Masson, M.; Germain, P. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Octeville-Cherbourg Radioecology Lab., 50 - Octeville -Cherbourg (France); Siclet, F. [Electricite de France (EDF), 78 - Chatou (France)

    2004-07-01

    The quantification of radionuclides by direct Ge gamma-X spectrometry with energy below 100 keV requires the elementary composition knowledge of the sample or the development of a device for determining the mass attenuation coefficients. This is especially true for {sup 129}I which is characterised by a 29.7 keV X-ray and 39.6 keV gamma ray. An experimental equipment has been developed in order to obtain this mass attenuation coefficient as a function of the energy. The elementary composition of a sample could change according to the biological phase of the organism and the sample preparation. {sup 129}I concentrations have been measured in samples of seaweed (Fucus serratus and Laminaria digitata) collected monthly during one year nearby La Hague reprocessing plant. Its quantification in different parts of these seaweeds was also performed in order to study the activity distribution. This paper will present measurement methodology used for {sup 129}I determination and its concentration variations during one-year period and the organo-tropism of {sup 129}I in the two seaweeds. (author)

  6. Measurement of planetary surface composition by gamma-ray and neutron spectrometry - Preparatory studies for Mars and for the Moon by numerical simulations

    International Nuclear Information System (INIS)

    Gasnault, O.

    1999-01-01

    Gamma-ray and neutron spectrometry sets up a powerful tool of geological and geochemical characterization of planetary surfaces. This method allows to tackle some critical planet science questions: crustal and mantle compositions; ices; volcanism; alteration processes... Most of the neutrons and gamma photons result from the interactions of galactic cosmic rays with matter. The first chapter introduces the physics of these nuclear interactions in planetary soils and in detectors. Our work aims at optimizing the observations by specifying instrumental performances, and by highlighting relations between soil composition and neutron fluxes. Numerical simulations using the GEANT code from CERN support our analysis. The second chapter estimates the performances of the Germanium gamma-ray spectrometer for MARS SURVEYOR 2001. The result of simulations is compared to calibration measurements; then performances are calculated in flight configuration. The background at Mars is estimated to about 160 c/s. The instrument offers a fine sensitivity to: Fe, Mg, K, Si, Th, Cl and O. It will also be possible to measure U, Ti, H, C, S, Ca and Al. The emission lobes at the surface are calculated too. These measurements shall permit a better understanding of the Martian surface. The last chapter deals with fast neutrons [500 keV; 10 MeV] emitted by the Moon. The strong influence of oxygen is underlined. As observed by LUNAR PROSPECTOR, the integrated flux shows a pronounced dependence with regolith content in iron and titanium, allowing the mapping. The influence of the other chemical elements is quantified. A simple mathematical formula is suggested to estimate the integrated neutron flux according to soil composition. At last, a study of hydrogen effects on fast neutron flux is carried out; we examine the possibilities to quantify its abundance in the soil by this method. (author)

  7. 235Uranium isotope abundance certified reference material for gamma spectrometry EC nuclear reference material 171 certification report

    International Nuclear Information System (INIS)

    De Bievre, P.; Eschbach, H.L.; Lesser, R.; Meyer, H.; Audenhove, Van J.

    1986-01-01

    This certification report contains the information necessary for the final certification of EC nuclear reference material 171. It is also intended to inform the user of the reference material concerned on technical/scientific details which are not given in the certificate. The report describes the reference material which consists of sets of U 3 O 8 samples with five different 235 U/U abundances, filled in cylindrical aluminium cans. The can bottom serves as window for emitted gamma radiation. The report describes how the 235 U/U abundances were characterized, how the other properties relevant for gamma measurements were determined and gives all connected results as well as those from the verification measurements. Appendix A represents the draft certificate. 32 refs

  8. Preparation and certification of IAEA gamma-ray spectrometry reference materials RGU-1, RGTh-1 and RGK-1

    International Nuclear Information System (INIS)

    1987-08-01

    The IAEA noted a requirement for materials specifically designed for use in calibrating laboratory gamma-ray spectrometers used for the analysis of geological and uranium exploration samples. Following the recommendations of the Consultants' Group, arrangements were made with the CANMET, to undertake the preparation of a thorium and a uranium reference material to serve as IAEA AQCS certified reference materials. The result was the completion of RGU-1 and RGTh-1, which together with RGK-1, prepared by the AQCS, form a set of three materials for the calibration of laboratory gamma-ray spectrometers for potassium, uranium and thorium. The preparation of RGU-1, RGTh-1 and RGK-1 is described in this report

  9. The applications of vehicle borne and ground gamma ray spectrometry in environmental radioactivity survey and monitoring: examples from the Philippines

    International Nuclear Information System (INIS)

    Reyes, R.Y.; Petrache, C.A.; Garcia, N.Q.; Tabora, E.U.; Juson, J.G.

    2002-01-01

    In the light of the nuclear development all over the world, there is an increasing global awareness on matters related to radioactivity and radioactive accidents. As such, the Philippine Nuclear Research Institute (PNRI) acquired through a technical cooperation project with the International Atomic Energy Agency the vehicle borne (car borne) and portable (ground) gamma ray, spectrometers. The objectives of this project were to establish environmental baseline information on the natural radioactivity of the entire country and to generate radioelement maps for geological mapping and mineral resource assessment. The purpose of this paper is to present the results of the different surveys including the methodologies and techniques conducted in the country using both spectrometers in effectively mapping natural and man-made sources of radiation. A pilot survey was successfully carried out over the small island of Marinduque (989 km 2 ) using the combined car borne and ground gamma ray spectrometric survey techniques. This was in preparation of the planned nationwide survey using this approach. Highlight of this study was the production of the first natural radioactivity maps within the country. Interestingly, these maps closely reflect the local geology of Marinduque Island. Car borne gamma ray spectrometric surveys were likewise undertaken at the former US naval base in Subic and US airforce base in Clark. This was due to mounting public concern over the presence of possible radioactive contamination or materials left behind by the US military forces in these bases. Results using the gamma-ray spectrum ratio technique indicated the absence of man-made sources of radiation in areas monitored within the two bases. A sizeable part of Metro Manila, the capital of the Philippines, has also been covered by the car borne survey. Results discovered an area with high measurements of thorium. The radiation source is coming from an establishment that uses thorium nitrate in

  10. Analytical laboratories method No. 4001 - automatic determination of U-235 wt% in a uranium matrix by gamma spectrometry

    International Nuclear Information System (INIS)

    1987-01-01

    This method is designed to automatically measure the U-235 concentration of various uranium-containing matrices (e.g., UO 3 , UF 4 , U 3 O 8 , sump samples, UNH, residues, etc.). Analyses are performed using a computer controlled sample changer. The technique is applicable to samples ranging from 0.20 to 20.0 wt% U-235. A complete gamma spectrometric U-235 analysis can be performed in two hours, or less

  11. Regional radiometric study over the east of Homs City depending on carborne gamma-ray spectrometry survey

    International Nuclear Information System (INIS)

    Aissa, Mosa

    1994-03-01

    The purpose of regional carborne gamma-ray survey over the east of Homs city is to determine the ground concentration of potassium, uranium and thorium. In the other hand, collecting essential information for future monitoring of any suspected leakage or contamination. In the presented study, we used four channel gamma-ray spectrometer with a 1.8 liter NaI(TI) detector, supplied by the IAEA 1988. About 1205 records of data was accomplished over the area, the car was run at 15-25 km/hr. Potassium, uranium, thorium, and total gamma-ray counts were recorded every 100 m and stored on HD with fiducial. Diurnal variations in the content of atmospheric radon in area were indicated by base station. The background counting-rate variations was obtained from the counts recorded over the Al-Furat river. Stripping ratios and window sensitivities are determined experimentally before the survey operations. The processing of the raw data was done with Pc-computer at SAEC software had written using Fortran, for date validation, editing, corrections, and gridding. The contour maps of seven parameters of Ur, U, Th (ppm), %K, and U/Th, U/K, Th/K ratios had drawn with the help of Surfer program, in which these maps showed without high concentration, They, infect, reflect the natural concentrations of radioactive elements in the concerned area. (Author). 14 refs., 12 figs., 10 tabs

  12. The high-spin 178m2Hf isomer: production, chemical and isotopic separations, gamma spectrometry and internal conversion electrons spectrometry

    International Nuclear Information System (INIS)

    Kim, J.B.

    1993-01-01

    The high-spin isometric state of the nucleus 178Hf is a challenge for new and exotic nuclear physics studies. With its long half-life of 31 years, the production of a reasonable micro-weight quantity, with an isometric to ground state ratio as high as 5 per cent, is now regularly performed by intensive irradiations of ytterbium targets with helium ions of 36 MeV. Using sur-enriched, at 99,998 per cent, ytterbium 176 that we have prepared at the PARIS mass separator, the isomer purity has been improved. Targets of such material but also of enriched stable isotopes of hafnium have been prepared by electro-spraying of methanolic and acetic solutions. By inelastic diffusion of protons and deuton on these targets, the energy of the first state of the rotation band built on the isomer has been measured. Isotopic separations of the isomer have been performed, with a yield greater than 20 per cent, by the use of isotopically pure hafnium 176 as carrier. The separated beam of the mass 178 allowed to record the complete hyperfine spectrum of the isomer and to measure, for the first time, the magnetic dipole moment and the electric quadrupole moment. Isomer targets, implanted in various materials like copper, iron and hafnium monocrystal, provide the opportunity to accurately measure gamma and internal conversion decay of this nuclei and so to precise the multipolarity mixing of all transitions from K=16 + to K=8 - . (author). 49 refs., 47 figs., 11 tabs

  13. In situ calibration of the Gamma Reaction History instrument using reference samples (“pucks” for areal density measurements

    Directory of Open Access Journals (Sweden)

    Hoffman N.M.

    2013-11-01

    Full Text Available The introduction of a sample of carbon, for example a disk or “puck”, near an imploding DT-filled capsule creates a source of 12C gamma rays that can serve as a reference for calibrating the response of the Gamma Reaction History (GRH detector [1]. Such calibration is important in the measurement of ablator areal density ⟨ρR⟩abl in plastic-ablator DT-filled capsules at OMEGA [2], by allowing ⟨ρR⟩abl to be inferred as a function of ratios of signals rather than from absolute measurements of signal magnitudes. Systematic uncertainties in signal measurements and detector responses therefore cancel, permitting more accurate measurements of ⟨ρR⟩abl.

  14. In-situ thermal annealing of on-membrane silicon-on-insulator semiconductor-based devices after high gamma dose irradiation.

    Science.gov (United States)

    Amor, S; André, N; Kilchytska, V; Tounsi, F; Mezghani, B; Gérard, P; Ali, Z; Udrea, F; Flandre, D; Francis, L A

    2017-05-05

    In this paper, we investigate the recovery of some semiconductor-based components, such as N/P-type field-effect transistors (FETs) and a complementary metal-oxide-semiconductor (CMOS) inverter, after being exposed to a high total dose of gamma ray radiation. The employed method consists mainly of a rapid, low power and in situ annealing mitigation technique by silicon-on-insulator micro-hotplates. Due to the ionizing effect of the gamma irradiation, the threshold voltages showed an average shift of -580 mV for N-channel transistors, and -360 mV for P-MOSFETs. A 4 min double-cycle annealing of components with a heater temperature up to 465 °C, corresponding to a maximum power of 38 mW, ensured partial recovery but was not sufficient for full recovery. The degradation was completely recovered after the use of a built-in high temperature annealing process, up to 975 °C for 8 min corresponding to a maximum power of 112 mW, which restored the normal operating characteristics for all devices after their irradiation.

  15. In-situ pre-concentration through repeated sampling and pyrolysis for ultrasensitive determination of thallium in drinking water by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Liu, Liwei; Zheng, Huaili; Xu, Bincheng; Xiao, Lang; Chigan, Yong; Zhangluo, Yilan

    2018-03-01

    In this paper, a procedure for in-situ pre-concentration in graphite furnace by repeated sampling and pyrolysis is proposed for the determination of ultra-trace thallium in drinking water by graphite furnace atomic absorption spectrometry (GF-AAS). Without any other laborious enrichment processes that routinely result in analyte loss and contamination, thallium was directly concentrated in the graphite furnace automatically and subsequently subject to analysis. The effects of several key factors, such as the temperature for pyrolysis and atomization, the chemical modifier, and the repeated sampling times were investigated. Under the optimized conditions, a limit of detection of 0.01µgL -1 was obtained, which fulfilled thallium determination in drinking water by GB 5749-2006 regulated by China. Successful analysis of thallium in certified water samples and drinking water samples was demonstrated, with analytical results in good agreement with the certified values and those by inductively coupled plasma mass spectrometry (ICP-MS), respectively. Routine spike-recovery tests with randomly selected drinking water samples showed satisfactory results of 80-96%. The proposed method is simple and sensitive for screening of ultra-trace thallium in drinking water samples. Copyright © 2017. Published by Elsevier B.V.

  16. Hollow-fiber-supported liquid phase microextraction with in situ derivatization and gas chromatography-mass spectrometry for determination of chlorophenols in human urine samples.

    Science.gov (United States)

    Ito, Rie; Kawaguchi, Migaku; Honda, Hidehiro; Koganei, Youji; Okanouchi, Noriya; Sakui, Norihiro; Saito, Koichi; Nakazawa, Hiroyuki

    2008-09-01

    A simple and highly sensitive method that involves hollow-fiber-supported liquid phase microextraction (HF-LPME) with in situ derivatization and gas chromatography-mass spectrometry (GC-MS) was developed for the determination of chlorophenols (CPs) such as 2,4-dichlorophenol (DCP), 2,4,6-trichlorophenol (TrCP), 2,3,4,6-tetrachlorophenol (TeCP) and pentachlorophenol (PCP) in human urine samples. Human urine samples were enzymatically de-conjugated with beta-glucuronidase and sulfatase. After de-conjugation, HF-LPME with in situ derivatization was performed. After extraction, 2 microl of extract was carefully withdrawn into a syringe and injected into the GC-MS system. The limits of detection (S/N=3) and quantification (S/N>10) of CPs in the human urine samples are 0.1-0.2 ng ml(-1) and 0.5-1 ng ml(-1), respectively. The calibration curve for CPs is linear with a correlation coefficient of >0.99 in the range of 0.5-500 ng ml(-1) for DCP and TrCP, and of 1-500 ng ml(-1) for TeCP and PCP, respectively. The average recoveries of CPs (n=6) in human urine samples are 81.0-104.0% (R.S.D.: 1.9-6.6%) with correction using added surrogate standards. When the proposed method was applied to human urine samples, CPs were detected at sub-ng ml(-1) level.

  17. Feasibility of using in situ fusion for the determination of Co, Cr and Mn in Portland cement by direct solid sampling graphite furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Intima, Danielle Polidorio; de Oliveira, Elisabeth; Oliveira, Pedro Vitoriano

    2009-01-01

    In situ fusion on the boat-type graphite platform has been used as a sample pretreatment for the direct determination of Co, Cr and Mn in Portland cement by solid sampling graphite furnace atomic absorption spectrometry (SS-GF AAS). The 3-field Zeeman technique was adopted for background correction to decrease the sensitivity during measurements. This strategy allowed working with up to 200 μg of sample. The in situ fusion was accomplished using 10 μL of a flux mixture 4.0% m/v Na 2 CO 3 + 4.0% m/v ZnO + 0.1% m/v Triton (registered) X-100 added over the cement sample and heated at 800 deg. C for 20 s. The resulting mould was completely dissolved with 10 μL of 0.1% m/v HNO 3 . Limits of detection were 0.11 μg g - 1 for Co, 1.1 μg g - 1 for Cr and 1.9 μg g - 1 for Mn. The accuracy of the proposed method has been evaluated by the analysis of certified reference materials. The values found presented no statistically significant differences compared to the certified values (Student's t-test, p < 0.05). In general, the relative standard deviation was lower than 12% (n = 5).

  18. 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.

  19. In situ metathesis ionic liquid formation dispersive liquid-liquid microextraction for copper determination in water samples by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Stanisz, Ewa; Zgoła-Grześkowiak, Agnieszka

    2013-10-15

    In situ synthesis of ionic liquid extractant for dispersive liquid-liquid microextraction (in situ IL DLLME) combined with electrothermal atomic absorption spectrometry (ET AAS) for determination of copper in water samples was developed. Analytical signals were obtained without the back-extraction of copper from the IL phase prior to its determination by AAS. Some essential parameters of the microextraction and detection techniques such as the pH of sample solution, volume of components for in situ synthesis, matrix interferences and main parameters of graphite furnace atomizer have been studied. Under optimal conditions, high extraction efficiency for copper was achieved for the extraction of 0.7 µg L(-1) in 10.0 mL of sample solution employing 8 μL of 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide (HmimNTf2) as the extraction solvent. The detection limit was found as 0.004 µg L(-1) with an enrichment factor of 200. The relative standard deviation (RSD) for seven replicate measurements of 0.7 µg L(-1) in sample solution was 4%. The accuracy of the proposed method was evaluated by analysis of the Certified Reference Materials: NIST SRM 2709 (San Joaquin Soil), NBS SRM 2704 (Buffalo River Sediment), NRCC DOLT-2 (Dogfish Liver) and NIST SRM 1643e (Trace Element in Water). The measured copper contents in the reference materials were in satisfactory agreement with the certified values. The method was successfully applied to analysis of the tap, lake and mineral water samples. © 2013 Elsevier B.V. All rights reserved.

  20. In situ emulsification microextraction using a dicationic ionic liquid followed by magnetic assisted physisorption for determination of lead prior to micro-sampling flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Shokri, Masood; Beiraghi, Asadollah; Seidi, Shahram

    2015-01-01

    For the first time, a simple and efficient in situ emulsification microextraction method using a dicationic ionic liquid followed by magnetic assisted physisorption was presented to determine trace amounts of lead. In this method, 400 μL of 1.0 mol L −1 lithium bis (trifluoromethylsulfonyl) imide aqueous solution, Li[NTf 2 ], was added into the sample solution containing 100 μL of 1.0 mol L −1 1,3-(propyl-1,3-diyl) bis (3-methylimidazolium) chloride, [pbmim]Cl 2 , to form a water immiscible ionic liquid, [pbmim][NTf 2 ] 2 . This new in situ formed dicationic ionic liquid was applied as the acceptor phase to extract the lead-ammonium pyrrolidinedithiocarbamate (Pb-APDC) complexes from the sample solution. Subsequently, 30 mg of Fe 3 O 4 magnetic nanoparticles (MNPs) were added into the sample solution to collect the fine droplets of [pbmim][NTf 2 ] 2 , physisorptively. Finally, MNPs were eluted by acetonitrile, separated by an external magnetic field and the obtained eluent was subjected to micro-sampling flame atomic absorption spectrometry (FAAS) for further analysis. Comparing with other microextraction methods, no special devices and centrifugation step are required. Parameters influencing the extraction efficiency such as extraction time, pH, concentration of chelating agent, amount of MNPs and coexisting interferences were studied. Under the optimized conditions, this method showed high extraction recovery of 93% with low LOD of 0.7 μg L −1 . Good linearity was obtained in the range of 2.5–150 μg L −1 with determination coefficient (r 2 ) of 0.9921. Relative standard deviation (RSD%) for seven repeated measurements at the concentration of 10 μg L −1 was 4.1%. Finally, this method was successfully applied for determination of lead in some water and plant samples. - Highlights: • A dicationic ionic liquid was used as the extraction solvent, for the first time. • A simple and efficient in situ emulsification microextraction

  1. Rapid analysis of 226Ra in mine waters by gamma-ray spectrometry. Supervising Scientist report 103

    International Nuclear Information System (INIS)

    Johnston, A.; Martin, P.

    1995-01-01

    Techniques for the determination of 226 Ra in uranium mine waters by γ-ray spectrometry are examined with an emphasis on methods capable of completion within 1 to 3 days of receipt of the sample. Methods discussed utilise either: (i) the 186 keV 226 Ra γ-ray, with the contribution from 235 U being subtracted after a separate uranium determination, or (ii) measurement of ingrowing 222 Rn progeny, either by two successive counts or by a single count (together with an assumption that radon was not present at the time of sample preparation). A full analysis of the statistical uncertainties and systematic errors associated with each technique is presented

  2. 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.

  3. In situ Measurement of Pore-Water pH in Anoxic Sediments Using Laser Raman Spectrometry

    Science.gov (United States)

    Peltzer, E. T.; Luna, M.; Walz, P. M.; Zhang, X.; Brewer, P. G.

    2010-12-01

    Accurate measurement of the geochemical properties of sediment pore waters is of fundamental importance in ocean geochemistry and microbiology. Recent work has shown that the properties of pore waters can be measured rapidly in situ with a novel Raman based insertion probe (Zhang et al., 2010), and that data obtained from anoxic sediments on in situ dissolved methane concentrations are very different (~30x) than from recovered cores due the large scale degassing that occurs during core recovery (Zhang et al., submitted). Degassing of methane must carry with it via Henry’s Law partioning significant quantities of H2S, which is clearly detectable by smell during sample processing, and thus in situ measurement of H2S is also highly desirable. In practice, dissolved H2S is partitioned between the HS- and H2S species as a function of pH with pKa ~7 for the acid dissociation reaction. Since both species are Raman active full determination of the sulfide system is possible if the relative Raman cross sections are known. The diagenetic equations for these reactions are commonly summarized as: 2CH2O + SO4= ↔ 2HCO3- + H2S CH4 + SO4= ↔ HCO3- + HS- + H2O Three of the major components of these equations, CH4, SO4=, and H2S/HS-, are all observable directly by Raman spectroscopy; but the detection of HCO3- presents a challenge due to its low Raman cross section and thus poor sensitivity. We show that pore water pH, which is a good estimator of HCO3- if total CO2 or alkalinity are known, can be measured by observing the H2S / HS- ratio via the equation: pH = pKa + log([HS-]/[H2S]) thereby fully constraining these equations within a single measurement protocol. The Raman peak for HS- is at 2573 cm-1 and for H2S is at 2592 cm-1; thus the peaks are well separated and may easily be deconvoluted from the observed spectrum. We have determined the relative Raman cross sections by a series of laboratory measurements over a range of pH and by using the definition that when pH = p

  4. Determination and quantification of impurities found in samples of {sup 124}I using gamma spectrometry; Determinacao e quantificacao de impurezas encontradas em amostra de {sup 124}I usando a espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ronaldo Lins da; Delgado, Jose Ubiratan; Araujo, Miriam Taina Ferreira de; Laranjeira, Adilson da Silva; Poledna, Roberto; Veras, Eduardo de; Almeida, Maria Candida M. [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Braghirolli, Ana Maria S. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    {sup 124}I, positron emitter is produced in the IEN/CNEN-RJ and used in diagnosis image of tumors. In this radioisotope production process impurities appear and health agency requires that the level of these characteristics is quantified. These radionuclides emit gamma and X-radiation, allowing the identification and quantitation by gamma spectrometry. With the use of HPGE detector, coupled with the efficiency curve, was identified {sup 125}I and {sup 126}I. The impurity levels measured in the sample were in the range of 0.5% to 90%, respectively, indicating the feasibility of the method for controlling the quality of the radiopharmaceutical.

  5. Rapid and simultaneous in situ assessment of aflatoxins and stilbenes using silica plate imprinting mass spectrometry imaging.

    Science.gov (United States)

    de Oliveira, Diogo N; Ferreira, Mônica S; Catharino, Rodrigo R

    2014-01-01

    A fast and direct combination of techniques for simultaneous mycotoxin and phytoalexin identification in peanut skin and kernel is described. Silica Plate Imprinting Laser Desorption/Ionization Mass Spectrometry Imaging (SPILDI-MSI) is a powerful technique that exhibits great advantages, such as solvent-free and matrix-free characteristics, as well as no sample preparation or separation steps. It also permits accurate identification of mycotoxins and phytoalexins with unique fingerprint profiles in just a few seconds. Results are expressed as chemical images of the 4 identified types of aflatoxins (B1, B2, G1 and G2) and a stilbenoid (resveratrol). Also, SPILDI-MSI allows the comparison between the spatial distribution of aflatoxins and resveratrol found in kernel and skin. This novel application has proven to be useful for instantaneous qualitative assessment of aflatoxins and stilbenoids both in the peanut skin and kernel and offers precise tracking of fungal contamination in nuts and other foodstuffs.

  6. Rapid and simultaneous in situ assessment of aflatoxins and stilbenes using silica plate imprinting mass spectrometry imaging.

    Directory of Open Access Journals (Sweden)

    Diogo N de Oliveira

    Full Text Available A fast and direct combination of techniques for simultaneous mycotoxin and phytoalexin identification in peanut skin and kernel is described. Silica Plate Imprinting Laser Desorption/Ionization Mass Spectrometry Imaging (SPILDI-MSI is a powerful technique that exhibits great advantages, such as solvent-free and matrix-free characteristics, as well as no sample preparation or separation steps. It also permits accurate identification of mycotoxins and phytoalexins with unique fingerprint profiles in just a few seconds. Results are expressed as chemical images of the 4 identified types of aflatoxins (B1, B2, G1 and G2 and a stilbenoid (resveratrol. Also, SPILDI-MSI allows the comparison between the spatial distribution of aflatoxins and resveratrol found in kernel and skin. This novel application has proven to be useful for instantaneous qualitative assessment of aflatoxins and stilbenoids both in the peanut skin and kernel and offers precise tracking of fungal contamination in nuts and other foodstuffs.

  7. An analytical calculation of the peak efficiency for cylindrical sources perpendicular to the detector axis in gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Julio C. [Autoridad Regulatoria Nuclear, Laboratorio de Espectrometria Gamma-CTBTO, Av. Del Libertador 8250, C1429BNP Buenos Aires (Argentina)], E-mail: jaguiar@sede.arn.gov.ar

    2008-08-15

    An analytical expression for the so-called full-energy peak efficiency {epsilon}(E) for cylindrical source with perpendicular axis to an HPGe detector is derived, using point-source measurements. The formula covers different measuring distances, matrix compositions, densities and gamma-ray energies; the only assumption is that the radioactivity is homogeneously distributed within the source. The term for the photon self-attenuation is included in the calculation. Measurements were made using three different sized cylindrical sources of {sup 241}Am, {sup 57}Co, {sup 137}Cs, {sup 54}Mn, and {sup 60}Co with corresponding peaks of 59.5, 122, 662, 835, 1173, and 1332 keV, respectively, and one measurement of radioactive waste drum for 662, 1173, and 1332 keV.

  8. 'Dip-sticks' calibration handles self-attenuation and coincidence effects in large-volume gamma-ray spectrometry

    CERN Document Server

    Wolterbeek, H T

    2000-01-01

    Routine gamma-spectrometric analyses of samples with low-level activities (e.g. food, water, environmental and industrial samples) are often performed in large samples, placed close to the detector. In these geometries, detection sensitivity is improved but large errors are introduced due to self-attenuation and coincidence summing. Current approaches to these problems comprise computational methods and spiked standard materials. However, the first are often regarded as too complex for practical routine use, the latter never fully match real samples. In the present study, we introduce a dip-sticks calibration as a fast and easy practical solution to this quantification problem in a routine analytical setting. In the proposed set-up, calibrations are performed within the sample itself, thus making it a broadly accessible matching-reference approach, which is principally usable for all sample matrices.

  9. Determination of the natural radioactivity levels in north west of Dukhan, Qatar using high-resolution gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Al-Sulaiti, Huda, E-mail: h.al-sulaiti@surrey.ac.uk [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Radiation Protection and Chemicals Department, Ministry of Environment, P.O. Box 7634, Doha (Qatar); Nasir, Tabassum [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Department of Physics, Gomal University, D.I. Khan (Pakistan); Al Mugren, K.S. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Physics Department, Faculty of Sciences, Princess Nora Bint Abdul Rahman University, Riyadh (Saudi Arabia); Alkhomashi, N. [King Abdulaziz City of Science and Technology (KACST), P.O. Box 6086, Riyadh 11442 (Saudi Arabia); Al-Dahan, N. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Department of Physics, College of Science, University of Kerbala, Kerbala (Iraq); Al-Dosari, M. [Radiation Protection and Chemicals Department, Ministry of Environment, P.O. Box 7634, Doha (Qatar); Bradley, D.A. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Bukhari, S. [Information Systems Management Department, Ministry of Environment, P.O. Box 7634, Doha (Qatar); Matthews, M. [Centre of Environmental Health Engineering, Department of Civil Engineering, University of Surrey, Guildford GU2 7XH (United Kingdom); Regan, P.H. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Santawamaitre, T. [Radiation Protection and Chemicals Department, Ministry of Environment, P.O. Box 7634, Doha (Qatar); Malain, D.; Habib, A. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2012-07-15

    This study is aimed at the determination of the activity concentrations of naturally occuring and technologically enhanced levels of radiation in 34 representative soil samples that have been collected from an inshore oil field area which was found to have, in a previous study, the highest observed value of {sup 226}Ra concentration among 129 soil samples. The activity concentrations of {sup 238}U and {sup 226}Ra have been inferred from gamma-ray transitions associated with their decay progenies and measured using a hyper-pure germanium detector. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented, together with the values of the activity concentrations associated with the naturally occuring radionuclide chains for all the samples collected from NW Dukhan. Discrete-line, gamma-ray energy transitions from spectral lines ranging in energy from {approx}100 keV up to 2.6 MeV have been associated with characteristic decays of the various decay products within the {sup 235.8}U and {sup 232}Th radioactive decay chains. These data have been analyzed, under the assumption of secular equilibrium for the U and Th decay chains. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented. The weighted mean value of the activity concentrations of {sup 226}Ra in one of the samples was found to be around a factor of 2 higher than the values obtained in the previous study and approximately a factor of 10 higher than the accepted worldwide average value of 35 Bq/kg. The weighted mean values of the activity concentrations of {sup 232}Th and {sup 40}K were also deduced and found to be within the worldwide average values of 30 and 400 Bq/kg, respectively. Our previous study reported a value of 201.9{+-}1.5{sub Stat.}{+-}13{sub Syst.} Bq/kg for {sup 226}Ra in one sample and further investigation in the current work determined a measured value for {sup 226}Ra of 342.00{+-}1.9{sub Stat.}{+-}25{sub Syst

  10. Determination of primordial and cosmogenic radioactivity in achondritic meteorites by low-level, gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Muntean, R.A.

    1979-08-01

    A high-sensitivity, low-background gamma-ray spectrometer containing two 23 cm by 13 cm thallium-activated, sodium iodide detectors was used to measure long-lived primordial and cosmogenic radioactivity in a suite of achondritic meteorites. Potassium, thorium, uranium, and 26 Al abundances were established for sixteen brecciated eucrites, two unbrecciated eucrites, a nakhlite, a chassignite, and a unique meteorite from Antarctica by nondestructive counting techniques. In several cases, multiple samples of the same meteorite fall were examined. Concentrations ranged from 79.8 ppM to 1150 ppM for potassium, 55.6 ppb to 663 ppb for thorium, 18.1 ppb to 190 ppb for uranium, and 45.0 dpm/kg to 99.0 dpm/kg for 26 Al. In addition, a 137 Cs concentration of 264 dpm/kg was observed in the Allan Hills 77005,9 specimen

  11. Determination of a Thorium Content in Soil Samples by Means of Gamma-Activation Analysis and X-Ray Spectrometry

    CERN Document Server

    Maslov, O D; Gustova, M V; Dmitriev, S N

    2003-01-01

    A highly sensitive method based on the reaction ^{232}Th(\\gamma, n)^{231}Th (T_{1/2} = 25.5 h) is developed for determining thorium in soil and environmental samples with a thorium content at a level of 3x10^{-7} g/g. Samples were irradiated for 4 hours with a maximum photon energy of 24.5 MeV at a compact electron accelerator - the MT-25 microtron of FLNR, JINR. The average electron current was about 15 {\\mu}A. The irradiated samples were tested using an X-ray spectrometer with a Si(Li) detector and a resolution of 200 eV (Fe_{K\\alpha} - 6.4 keV).

  12. Near-optimum procedure for half-life measurement by high-resolution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Parker, J.L.

    1989-01-01

    A near-optimum procedure for using high-resolution γ-ray spectrometry to measure the half-lives of appropriate γ-ray- emitting-nuclides is presented. Among the important points of the procedure are the employment of the reference source method for implicit correction of pileup and deadtime losses; the use of full-energy peak-area ratios as the fundamental measured quantities; and continuous, high-rate data acquisition to obtain good results in a fraction of a half-life if desired. Equations are given for estimating the precision of the computed half-lives in terms of total measurement time, number of spectral acquisitions, and the precision of peak-area ratios. Results of 169 Yb half-life measurements are given as an example of the procedure's application. 3 refs., 2 tabs

  13. 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)

  14. Characterising in situ activation and degradation of hindered amine light stabilisers using liquid extraction surface analysis-mass spectrometry.

    Science.gov (United States)

    Paine, Martin R L; Barker, Philip J; Blanksby, Stephen J

    2014-01-15

    Changes in the molecular structure of polymer antioxidants such as hindered amine light stabilisers (HALS) is central to their efficacy in retarding polymer degradation and therefore requires careful monitoring during their in-service lifetime. The HALS, bis-(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate (TIN123) and bis-(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate (TIN292), were formulated in different polymer systems and then exposed to various curing and ageing treatments to simulate in-service use. Samples of these coatings were then analysed directly using liquid extraction surface analysis (LESA) coupled with a triple quadrupole mass spectrometer. Analysis of TIN123 formulated in a cross-linked polyester revealed that the polymer matrix protected TIN123 from undergoing extensive thermal degradation that would normally occur at 292°C, specifically, changes at the 1- and 4-positions of the piperidine groups. The effect of thermal versus photo-oxidative degradation was also compared for TIN292 formulated in polyacrylate films by monitoring the in situ conversion of N-CH3 substituted piperidines to N-H. The analysis confirmed that UV light was required for the conversion of N-CH3 moieties to N-H - a major pathway in the antioxidant protection of polymers - whereas this conversion was not observed with thermal degradation. The use of tandem mass spectrometric techniques, including precursor-ion scanning, is shown to be highly sensitive and specific for detecting molecular-level changes in HALS compounds and, when coupled with LESA, able to monitor these changes in situ with speed and reproducibility. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Analysis of 226Ra, 232Th 40К and 137Cs in samples of soil from some areas of Republic of Macedonia by using gamma spectrometry

    Directory of Open Access Journals (Sweden)

    Todorovik Aleksandra

    2012-01-01

    Full Text Available Taking into consideration the importance of the distribution and transfer of radio nuclides in soil, an attempt was made in this work to determine the concentration of 226Ra, 232Th 40К and 137Cs in the same. The concentrations of activity in the gamma-absorbed dose rates of the terrestrial naturally occurring radio nuclides, as follows, 226Ra, 232Th and 40K were determined in samples of soil collected from some parts of Republic of Macedonia, i.e. from three major cities in the Republic of Macedonia. The samples are taken by means of a special dosage dispenser which enables sampling of samples at a depth of 0-5 cm, 5-10cm and 10-15cm, thus disabling the sampling above these layers of soil. An identification of radio nuclides and assessment of their activity has been performed by applying gamma spectrometry. The time of counting for each sample was 65000 s. in order to obtain statistically small mistake. The spectrums were analyzed by a commercially available software GENIE-2000 received from Canberra, Austria. The activity of soil had wide range of values: 20.3 to 82.9 Bq kg-1for 226Ra, 16.1 to 82.5 Bq kg-1 for 232Th, 325 to 799.0 Bq kg-1for 40К and 9.1 to 24.3 Bq kg-1for 137Cs, respectively. The concentrations of these radio nuclides have been compared with the available data from the other countries. Natural environmental radioactivity and the associated external exposure due to gamma radiation depend primarily on the geological and geographical conditions. Namely, the specific levels of terrestrial environmental radiation are related to the type of rocks from which the soils originate. The obtained data indicate that the average value of activity of 232Th is about higher than the one of 226Ra The concentration of activity of 40К in the soil has greater value than 32Th and 226Ra in all soils. The causes for the existence of 137Cs in these soils are the nuclear explosions, waste radioactive materials and other incidents. It reaches the

  16. HI-resolution gamma spectrometry measurements of U-238, TH-232, K-40 and CS-137 concentrations in soil samples from Capao Island at CTEx

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Luciano S.R.; Oliveira, Celio J.V.; Vilela, Paulo R.T.; Vital, Helio C., E-mail: vital@ctex.eb.br [Centro Tecnologico do Exercito (DDQBN/CTEX), Rio de Janeiro, RJ (Brazil). Div. de Defesa Quimica, Biologica e Nuclear. Secao de Defesa Nuclear

    2013-07-01

    Absolute soil concentrations of U-238, Th-232, K-40 and Cs-137 samples collected from Capao Island have been measured by using Hi-Resolution Gamma HPGe Spectrometry. The area of interest encompasses an embankment in a mangrove swamp in Guaratiba, Rio de Janeiro, where nuclear, chemical and biological defense laboratories of the Brazilian Army Technology Center (CTEx) are located. In order to ensure that no significant environmental impact has resulted from neutron physics experiments performed in a graphite subcritical assembly in addition to the operation of two cesium-driven irradiating facilities, routine monitoring of those isotopes have been regularly performed. A total of eight 250 ml samples of mangrove and embankment soils were extracted from four sites of known coordinates within an area of 300 x 300 m{sup 2} and remained stored for a minimum thirty-day period to allow equilibrium to be reached. Collection and preparation of samples were made according to previously established procedures. High purity germanium detectors were used to obtain high-resolution gamma spectra and counting times were required to exceed 30 hours in order to yield sufficient statistical accuracy. Energy and efficiency calibration curves of the counting system were determined by using the GENIE 2000 software for analysis of the gamma spectrum generated by nine standard sources with a total of 11 peak energies ranging from 0.05 to 1.3 MeV. The results, corrected for background, have been expressed as absolute specific activities. All experiments have been made in the Laboratory for Identification of Radiological Agents (LIAR) at CTEx. No trace of cesium-137 has been found and the measured levels of uranium-238, in the order of 10 Bq/kg, are close to the global mean. However, some data have been found to slightly exceed the expected normal range for thorium-232 (60% of samples) and potassium-40 (20% of samples). Since there is no handling of those isotopes in the site or others that

  17. Calibration of a Gamma Spectrometry System Used for the Determination of Cs-137 in Spanish Soils; Puesta a Punto de un sistema de Expectrometria Gamma para la Determinacion de Cs-137 en Suelos Espanoles

    Energy Technology Data Exchange (ETDEWEB)

    Barreraa, M.; Romero, M. L.; Valino, F.

    2008-07-01

    The document describes the methodology used at CIEMAT in order to determine, by gamma spectrometry, the background levels of the radionuclide Cs-137 in soils of the Spanish peninsular territory. the work is a part of an extensive research project developed jointly by the University of the Basque Country (UPV-EHU) and the CIEMAT, endellite Content and migration of radiocaesium and radiostrontium in Spanish soils, which is funded by the Plan I+D of the Spanish Nuclear Security Council (CSN). The objective of the project is to establish the reference levels of man-made radionuclides in Spanish soils, with respect to which the evaluation of a possible posterior accidental release of radioactive material could be appraised. The activity concentration of the fission products Cs-137 has been determined in 34 soil cores extracted from representative Spanish soils type zones. This publication describes the experimental system employed, its calibration, the particular conditions applied to perform the measurements, as well as the experimental validation of the methodology. The activity profiles and inventories of the radioactive element so obtained are also presented. The estimation of the background Cs-137 reference levels, will provide a basis for later applications as the study of the spatial distribution in the region, the determination of the correlation between the deposited activity and the meteorological conditions, or the calculation of the specific migration parameters of the radioactive elements in Mediterranean conditions. (Author) 15 refs.

  18. In situ prompt gamma-ray activation analysis of water pollutants using a shallow 252Cf-HPGe probe

    International Nuclear Information System (INIS)

    Chung Chien; Tseng Tzucheng

    1988-01-01

    A shallow 252 Cf-HPGe probe used for in situ prompt γ-ray activation of water pollutants is described. A 2.7 μg 252 Cf neutron source and a 10% HPGe detector are inserted into a waterproof stainless steel probe, which is designed to be submerged and recovered in field operation. A laboratory test is performed to obtain the neutron flux distribution and prompt γ-ray contribution to the HPGe detector counts from around the submerged probe. The concentrations of toxic cadmium and chlorine in water are determined in the prompt γ-ray spectrum. The detection limit of industrial pollutants and some improvements of the current design are discussed. (orig.)

  19. Determination iodine in biological materials using instrumental neutron activation and anti-coincidence gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Zhang, W.H.; Chatt, A.

    1997-01-01

    Iodine is an element of interest in nutritional research. Its lower limit of safe and adequate daily dietary intake for adults varies between 150 and 200 micrograms per day. In the present study, an epithermal instrumental neutron activation analysis (EINAA) method in conjunction with anti-coincidence counting has been developed for the determination of ppb levels of iodine in individual food items. Typically 200-300 mg of a sample are irradiated for 10 or 20 minutes at the Dalhousie University SLOWPOKE-2 reactor in an epithermal flux of 1x10 11 n cm -2 s -1 , followed by 1 min decay and then counting for 30 min. The 443-keV gamma-ray of 128 I is used for measuring iodine content by anti-coincidence counting. The anti-coincidence spectrometer consists of a 25% HPGe detector surrounded by a 10''x10'' NaI(TI) annulus and a 3''x3'' NaI(TI) plug. This system has a peak-to-Compton ratio of about 650 to 1 for the 661.6-keV photopeak of 137 Cs. The Compton background resulting from the scattering of many gamma-rays of energies higher than 443 keV can be reduced by a factor of about 4 using anti-coincidence counting compared to conventional counting. The detection limit for iodine can be improved by a factor of 2 to 5 depending on the sample matrix, dead time, position of the annulus and counting geometry among several other factors.The lowest detection limit of 5 ppb can be achieved for low-salt foods. This limit is comparable to that obtained by a preconcentration NAA (PNAA) method. However, a detection limit of 20 ppb is more realistic for samples containing high amounts of Na, Cl and Al. The results obtained for many reference materials are in good agreement with the certified values and those reported by the PNAA method. Details of the methods and results will be reported

  20. Determination iodine in biological materials using instrumental neutron activation and anti-coincidence gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W.H.; Chatt, A. [Dalhousie University, Halifax, Nova Scotia (Canada). Radiochemistry Research Laboratory

    1997-10-01

    Iodine is an element of interest in nutritional research. Its lower limit of safe and adequate daily dietary intake for adults varies between 150 and 200 micrograms per day. In the present study, an epithermal instrumental neutron activation analysis (EINAA) method in conjunction with anti-coincidence counting has been developed for the determination of ppb levels of iodine in individual food items. Typically 200-300 mg of a sample are irradiated for 10 or 20 minutes at the Dalhousie University SLOWPOKE-2 reactor in an epithermal flux of 1x10{sup 11} n cm{sup -2} s{sup -1}, followed by 1 min decay and then counting for 30 min. The 443-keV gamma-ray of {sup 128}I is used for measuring iodine content by anti-coincidence counting. The anti-coincidence spectrometer consists of a 25% HPGe detector surrounded by a 10``x10`` NaI(TI) annulus and a 3``x3`` NaI(TI) plug. This system has a peak-to-Compton ratio of about 650 to 1 for the 661.6-keV photopeak of {sup 137}Cs. The Compton background resulting from the scattering of many gamma-rays of energies higher than 443 keV can be reduced by a factor of about 4 using anti-coincidence counting compared to conventional counting. The detection limit for iodine can be improved by a factor of 2 to 5 depending on the sample matrix, dead time, position of the annulus and counting geometry among several other factors.The lowest detection limit of 5 ppb can be achieved for low-salt foods. This limit is comparable to that obtained by a preconcentration NAA (PNAA) method. However, a detection limit of 20 ppb is more realistic for samples containing high amounts of Na, Cl and Al. The results obtained for many reference materials are in good agreement with the certified values and those reported by the PNAA method. Details of the methods and results will be reported 6 refs., 2 tabs.

  1. Gamma-ray spectrometry applied to agricultural soil in the northwest of the State of Rio de Janeiro; Gamaespectrometria aplicada em solo agricola no noroeste do Estado do Rio de Janeiro

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Andrea Cristina Lima dos; Nascimento, Carlos Tadeu Carvalho do [Instituto de Geociencias, Universidade de Brasilia, DF (Brazil); Menezes, Paulo de Tarso Luiz, E-mail: andrealima@unb.br, E-mail: carlostadeu@unb.br, E-mail: ptarsomenezes@pq.cnpq.br [Faculdade de Geologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ (Brazil)

    2008-04-15

    The present work presents the use of gamma-ray spectrometry applied to precision agriculture in a sub-tropical area. Our dataset comprises measurements both in rock and residual soil. The soil dataset shows a reduction of 20% on U and Th and 10% on K, when compared to rock samples. This difference could be related to K supplementation associated to chemical fertilization. (author)

  2. Determination of methylmercury by electrothermal atomic absorption spectrometry using headspace single-drop microextraction with in situ hydride generation

    International Nuclear Information System (INIS)

    Gil, Sandra; Fragueiro, Sandra; Lavilla, Isela; Bendicho, Carlos

    2005-01-01

    A new method is proposed for preconcentration and matrix separation of methylmercury prior to its determination by electrothermal atomic absorption spectrometry (ETAAS). Generation of methylmercury hydride (MeHgH) from a 5-ml solution is carried out in a closed vial and trapped onto an aqueous single drop (3-μl volume) containing Pd(II) or Pt(IV) (50 and 10 mg/l, respectively). The hydrogen evolved in the headspace (HS) after decomposition of sodium tetrahydroborate (III) injected for hydride generation caused the formation of finely dispersed Pd(0) or Pt(0) in the drop, which in turn, were responsible for the sequestration of MeHgH. A preconcentration factor of ca. 40 is achieved with both noble metals used as trapping agents. The limit of detection of methylmercury was 5 and 4 ng/ml (as Hg) with Pd(II) or Pt(IV) as trapping agents, and the precision expressed as relative standard deviation was about 7%. The preconcentration system was fully characterised through optimisation of the following variables: Pd(II) or Pt(IV) concentration in the drop, extraction time, pH of the medium, temperatures of both sample solution and drop, concentration of salt in the sample solution, sodium tetrahydroborate (III) concentration in the drop and stirring rate. The method has been successfully validated against two fish certified reference materials (CRM 464 tuna fish and CRM DORM-2 dogfish muscle) following selective extraction of methylmercury in 2 mol/l HCl medium

  3. Analysis of fission product mixtures in fresh fallout from Chinese nuclear explosion of January 23, 1976 by Ge(Li)gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Mishra, U.C.; Sethi, S.K.; Negi, B.S.

    1977-01-01

    China conducted its seventeenth nuclear explosion (sixteenth in the athmosphere) at Lop Nor (40 0 N, 90 0 E) on January 23, 1976. Frish radioactive fallout sample from this test was collected by swiping the exposed portion of the engine covers of an Air India, Boeing 707 air-craft which arrived at Bombay from Tokyo on January 28, 1976. The concentration of various radionuclides in the sample was estimated by Ge(Li) gamma-ray spectrometry. Activities of short-lived radionuclides e.g. Mo 99-Tc 99, Ru 103, Rh 105, Ag 111, I 131, Te 132-I 133, Ba 140-La 140, Ce 141, Ce 143, Nd 147, U 237 and Np 239 were determined. In addition to short-lived radionuclides, other long-lived radionuclides e.g. Ce 144, Sb 125, Cs 137, Ru 106, Zr 95-Nb 95 were also observed. The results obtained have been discussed to identify the fissile material used in the explosion by using the observed activity ratios of some selected pairs of radionuclides frish fallout. The activity ratios of U 237 and Np 239 as well as their ratios with respect to other fission products have been used to identify the type of nuclear device. (orig.) [de

  4. Analysis of the gamma spectrometry {sup 210}Pb radioisotope in river bottom sediments of the hydrographic sub-basins around the UTM-Caldas

    Energy Technology Data Exchange (ETDEWEB)

    Dutra, Pedro H.; Carvalho Filho, Carlos A.; Moreira, Rubens M.; Menezes, Maria Angela B.C.; Oliveira, Aline F.G. de, E-mail: pedrohenrique.dutra@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Silva, Nivaldo C., E-mail: ncsilva@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Viana, Valquiria F.L., E-mail: valquiria.flviana@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Instituto de Ciencias Biologicas

    2015-07-01

    The uranium mine of Caldas, currently named Ore Treatment Unit (UTM-Caldas), is sited at the Pocos de Caldas Plateau (Minas Gerais State) and was the first uranium mineral-industrial complex in Brazil. It has been installed since 1982 and now it is under decommissioning process. Taking into account the potential sources of contamination and the assessment of the impact of the mine, based on the presence of radionuclides from the radioactive decay series of natural {sup 238}U, the aim of the article is to present the distribution of {sup 210}Pb in the stream bottom sediments of the study area that consists of the Taquari watershed, sub-divided by its three major sub-basins: Consulta stream, Soberbo stream and Taquari river. The radionuclide activity concentrations were measured in sediment samples that were collected in twelve collecting points, during four sampling campaigns, carried out in the dry and rainy seasons of 2010 and 2011. The results of the {sup 210}Pb concentration activity were obtained by gamma spectrometry performed in both high and low energy CANBERRA detectors. The results point out that the UTM-Caldas is influencing on the bottom sediment distribution of {sup 210}Pb activity in its neighborhood. However, a more detailed study should be done in order to identify if there is another source of {sup 210}Pb in the study area, such as a geogenic anomaly, that may contributing to the local increment of {sup 210}Pb activity. (author)

  5. Rapid environmental surveying using mobile gamma ray spectrometry Processing of results from the RESUME99 exercise, Gaevle, Sweden

    CERN Document Server

    Smetkurst, M A

    2000-01-01

    Data from mobile measuring teams participating in the RESUME99 Fixed Route exercise in Sweden have been processed to facilitate a detailed comparison between the data sets. The exercise was organised by the Swedish Radiation Protection Institute (SSI) and is part of the BOK-1.2 project Mobile Measurements and Measurements Strategies within the Nordic Nuclear Safety Research (NKS) programme for 1998-2000. 11 car borne gamma ray spectrometer systems measured a fixed route in the vicinity of Gaevle in Sweden so that the capabilities of the different measuring systems in determining the levels and patterns of sup 1 37Cs contamination along the route could be studied. This report describes how the data sets from the different measuring systems were projected into the known trace of the fixed route so that the results can be compared. Estimates of equivalent surface activity of sup 1 37Cs from the different measuring systems were normalised to data obtained by the Danish Emergency management Agency (system DKA1) an...

  6. A pulse-shape discrimination method for improving Gamma-ray spectrometry based on a new digital shaping filter

    Science.gov (United States)

    Qin, Zhang-jian; Chen, Chuan; Luo, Jun-song; Xie, Xing-hong; Ge, Liang-quan; Wu, Qi-fan

    2018-04-01

    It is a usual practice for improving spectrum quality by the mean of designing a good shaping filter to improve signal-noise ratio in development of nuclear spectroscopy. Another method is proposed in the paper based on discriminating pulse-shape and discarding the bad pulse whose shape is distorted as a result of abnormal noise, unusual ballistic deficit or bad pulse pile-up. An Exponentially Decaying Pulse (EDP) generated in nuclear particle detectors can be transformed into a Mexican Hat Wavelet Pulse (MHWP) and the derivation process of the transform is given. After the transform is performed, the baseline drift is removed in the new MHWP. Moreover, the MHWP-shape can be discriminated with the three parameters: the time difference between the two minima of the MHWP, and the two ratios which are from the amplitude of the two minima respectively divided by the amplitude of the maximum in the MHWP. A new type of nuclear spectroscopy was implemented based on the new digital shaping filter and the Gamma-ray spectra were acquired with a variety of pulse-shape discrimination levels. It had manifested that the energy resolution and the peak-Compton ratio were both improved after the pulse-shape discrimination method was used.

  7. Measurement of natural radioactivity in building materials of Namakkal, Tamil Nadu, India using gamma-ray spectrometry.

    Science.gov (United States)

    Ravisankar, R; Vanasundari, K; Chandrasekaran, A; Rajalakshmi, A; Suganya, M; Vijayagopal, P; Meenakshisundaram, V

    2012-04-01

    The natural level of radioactivity in building materials is one of the major causes of external exposure to γ-rays. The primordial radionuclides in building materials are one of the sources of radiation hazard in dwellings made of these materials. By the determination of the radioactivity level in building materials, the indoor radiological hazard to human health can be assessed. This is an important precautionary measure whenever the dose rate is found to be above the recommended limits. The aim of this work was to measure the specific activity concentration of (226)Ra, (232)Th and (40)K in commonly used building materials from Namakkal, Tamil Nadu, India, using gamma-ray spectrometer. The radiation hazard due to the total natural radioactivity in the studied building materials was estimated by different approaches. The concentrations of the natural radionuclides and the radium equivalent activity in studied samples were compared with the corresponding results of different countries. From the analysis, it is found that these materials may be safely used as construction materials and do not pose significant radiation hazards. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Bioactive compounds of fourth generation gamma-irradiated Typhoniumflagelliforme Lodd. mutants based on gas chromatography-mass spectrometry

    Science.gov (United States)

    Sianipar, N. F.; Purnamaningsih, R.; Rosaria

    2016-08-01

    Rodent tuber (Typhonium flagelliforme Lodd.) is an Indonesian anticancer medicinal plant. The natural genetic diversity of rodent tuber is low due to vegetative propagation. Plant's genetic diversity has to be increased for obtaining clones which contain a high amount of anticancer compounds. In vitro calli were irradiated with 6 Gy of gamma ray to produce in vitro mutant plantlets. Mutant plantlets were acclimated and propagated in a greenhouse. This research was aimed to identify the chemical compounds in the leaves and tubers ofthe fourth generation of rodent tuber's vegetative mutant clones (MV4) and control plantsby using GC- MS method. Leaves and tubers of MV4 each contained 2 and 5 anticancer compounds which quantities were higher compared to control plants. MV4 leaves contained 5 new anticancer compounds while its tubers contained 3 new anticancer compounds which were not found in control. The new anticancer compounds in leaves were hexadecanoic acid, stigmast-5-en-3-ol, ergost-5-en-3-ol, farnesol isomer a, and oleic acid while the new anticancer compounds in tubers were alpha tocopherol, ergost-5-en-3-ol, and beta-elemene. Rodent tuber mutant clones are very potential to be developed into anticancer drugs.

  9. Efficient in situ synthetic routes of polyaniline/poly(vinyl alcohol)/TiO2 nanocomposites using gamma irradiation

    Science.gov (United States)

    Afify, T. A.; Ghazy, O. A.; Saleh, H. H.; Ali, Z. I.

    2018-02-01

    Gamma radiation was used to prepare nanocomposites based on polyaniline/titanium dioxide (PANI/TiO2) or polyaniline/poly (vinyl alcohol)/titanium dioxide (PANI/PVA/TiO2). It was found that PANI/TiO2 in the form of nanocomposite as shown by the UV/vis spectroscopy. This was through the appearance and shift of two absorption peaks at 340 and 598 nm. The SEM micrographs of the PANI/TiO2 nanocomposites showed a fibrous morphology before the treatment with HCl. The TiO2 nanoparticles are clearly seen to be precipitated on the PANI fibers and the morphology changed towards the sheets shape with highly distribution on PANI surface. The transmission electron microscopy (TEM) image confirms the fibrous shape of the PANI and spherical shape of TiO2 nanoparticles. The XRD study showed a several diffraction patterns of TiO2 nanoparticles confirming the PANI/TiO2 and PANI/PVA/TiO2 nanocomposites. The FT-IR analysis indicated that there is an interfacial interaction existed between the PANI and its inorganic counterpart of TiO2 nanoparticles. The dielectric constant of the PANI/PVA showed the lowest values and was increased by either doping with TiO2 or increasing irradiation dose.

  10. High energy resolution and high count rate gamma spectrometry measurement of primary coolant of generation 4 sodium-cooled fast reactor; Spectrometrie gamma haute resolution et hauts taux de comptage sur primaire de reacteur de type generation 4 au sodium liquide

    Energy Technology Data Exchange (ETDEWEB)

    Coulon, R.

    2010-11-10

    Sodium-cooled Fast Reactors are under development for the fourth generation of nuclear reactor. Breeders reactors could gives solutions for the need of energy and the preservation of uranium resources. An other purpose is the radioactive wastes production reduction by transmutation and the control of non-proliferation using a closed-cycle. These thesis shows safety and profit advantages that could be obtained by a new generation of gamma spectrometry system for SFR. Now, the high count rate abilities, allow us to study new methods of accurate power measurement and fast clad failure detection. Simulations have been done and an experimental test has been performed at the French Phenix SFR of the CEA Marcoule showing promising results for these new measurements. (author) [French] Les reacteurs a neutrons rapides refroidis au sodium sont en developpement en vue d'assurer une quatrieme generation de reacteurs repondant a la demande energetique, tout en assurant la preservation des ressources d'uranium par un fonctionnement en surgenerateur. L'objectif de la filiere est egalement d'ameliorer la gestion de la radiotoxicite des dechets produits par transmutation des actinides mineurs et de controler la non-proliferation par un fonctionnement en cycle ferme. Une instrumentation de surveillance et de controle de ce type de reacteur a ete etudiee dans cette these. La spectrometrie gamma de nouvelle generation permet, par les hauts taux de traitement aujourd'hui accessibles, d'envisager de nouvelles approches pour suivre avec une precision accrue la puissance neutronique et de detecter plus precocement des ruptures de gaine combustible. Des simulations numeriques ont ete realisees et une campagne d'essai a ete menee a bien sur le reacteur Phenix de Marcoule. Des perspectives prometteuses ont ete mises en exergue pour ces deux problematiques

  11. Mechanistic insights into the reduction of carbon dioxide on tin and bismuth electrodes using in situ infrared spectroscopy and differential electrochemical mass spectrometry

    Science.gov (United States)

    Baruch, Maor F.

    The factors that govern the electrochemical reduction of CO2 on Sn and Bi electrodes were studied. Chapter 1 discusses the relevant literature, the merits of reducing CO2 electrochemically, the ways in which CO2 reduction systems are characterized, and the outstanding challenges. Chapter 2 describes the design and construction of a differential electrochemical mass spectrometry (DEMS) system that can be used to probe the products of electrochemical reactions in situ and in real time. In Chapter 3, the role of surface oxides and hydroxides in the reduction of CO2 on Sn electrodes is discussed. in situ attenuated total reflectance infrared (ATR-IR) spectroscopy is the main analytical technique by which the system was studied. Peaks that are attributed to a surface-bound Sn carbonate are present under conditions that are suitable for CO2 reduction. A strong correlation between the presence of these peaks and catalytic activity exists with respect to the applied potential, the pH of the electrolyte, and the surface condition of the electrode. X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and electrochemical analysis were also used characterize the catalysts. Based on these data, a mechanism for the reduction of CO2 on Sn cathodes is proposed. The roles of morphology and surface oxide presence in the reduction of CO2 on Bi cathodes are discussed in Chapter 4. ATR-IR spectroscopy, XPS, EDX, SEM, cyclic voltammetry, and preparative electrolysis are used to demonstrate that, unlike Sn, Bi electrodes do not possess oxide-dependent catalytic behavior. Instead, it is shown that Bi electrodes are highly sensitive to morphological changes in surface structure, and that surface roughness is detrimental to HCOO-- production from CO2. Finally, it is shown that oxide-derived Bi, formed by the in situ reduction of Bi2O3 nanoparticles at cathodic potentials, can reduce CO2 to HCOO-- at near unit efficiencies at

  12. Natural gamma-ray spectrometry, lithofacies, and depositional environments of selected upper Cretaceous marine mudrocks, western United States, including tropic shale and tununk member of Mancos shale

    International Nuclear Information System (INIS)

    Zelt, F.B.

    1985-01-01

    In-situ measurements of gamma-ray spectra provide estimates of the potassium, thorium, the pre-weathering uranium contents of outcropping marine mudrocks. Th/U is a sensitive indicator of the oxidation potential of paleoenvironments of deposition of Phanerozoic epi- and pericontinental marine deposits. High (>10 x 10 -4 ) ratios of uranium or organic carbon occur in phosphatic and cherty mudrocks; low ( -4 ) ratios occur in nonmarine mudrocks and in epicontinental marine strata that were deposited during unusual paleo-oceanographic conditions, which sometimes accompanied global extinction events. Spectrometric data compliment sedimentologic data in defining five lithologic/geochemical facies in marine mudrocks of the Cenomanian-Turonian Greenhorn marine cycle. The rock units that were studied in Colorado, New Mexico, and Utah are the Graneros Shale, Greenhorn Limestone, Garlile Shale, Mancos Shale, and Tropic Shale. Results of analyses of the different rock units are used to explain various geological structures of the area under investigation. Outcrops and geophysical well logs combine to indicate the distribution of lithologic/geochemical focus of marine mudrocks

  13. Nonequilibrium hollow-fiber liquid-phase microextraction with in situ derivatization for the measurement of triclosan in aqueous samples by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Zhao, Ru-Song; Yuan, Jin-Peng; Li, Hai-Fang; Wang, Xu; Jiang, Ting; Lin, Jin-Ming

    2007-04-01

    Hollow-fiber liquid-phase microextraction (HF-LPME), a relatively new sample preparation technique, has attracted much interest in the field of environmental analysis. In the current study, a novel method based on hollow-fiber liquid-phase microextraction with in situ derivatization and gas chromatography-mass spectrometry for the measurement of triclosan in aqueous samples is described. Hollow-fiber liquid-phase microextraction conditions such as the type of extraction solvent, the stirring rate, the volume of derivatizing reagent, and the extraction time were investigated. When the conditions had been optimized, the linear range was found to be 0.05-100 microg l(-1) for triclosan, and the limit of detection to be 0.02 microg l(-1). Tap water and surface water samples collected from our laboratory and Wohushan reservoir, respectively, were successfully analyzed using the proposed method. The recoveries from the spiked water samples were 83.6 and 114.1%, respectively; and the relative standard deviation (RSD) at the 1.0 microg l(-1) level was 6.9%.

  14. Miniaturized hollow fiber assisted liquid-phase microextraction with in situ derivatization and gas chromatography-mass spectrometry for analysis of bisphenol A in human urine sample.

    Science.gov (United States)

    Kawaguchi, Migaku; Ito, Rie; Okanouchi, Noriya; Saito, Koichi; Nakazawa, Hiroyuki

    2008-07-01

    A new method that involves miniaturized hollow fiber assisted liquid-phase microextraction (HF-LPME) with in situ derivatization and gas chromatography-mass spectrometry (GC-MS) is described for the determination of trace amounts of bisphenol A (BPA) in human urine samples. The detection limit and the quantification limit of BPA in human urine sample are 0.02 and 0.1 ng ml(-1) (ppb), respectively. The calibration curve for BPA is linear with a correlation coefficient of >0.999 in the range of 0.1-50 ng ml(-1). The average recoveries of BPA in human urine samples spiked with 1 and 5 ng ml(-1) BPA are 101.0 (R.S.D.: 6.7%) and 98.8 (R.S.D.: 1.8%), respectively, with correction using the added surrogate standard, bisphenol A-(13)C12. This simple, accurate, sensitive and selective analytical method can be applicable to the determination of trace amounts of BPA in human urine samples.

  15. Discrimination of Bacillus anthracis Spores by Direct in-situ Analysis of Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Youngsu; Lee, Jonghee; Kim, Seongsoo [Agency for Defense Development, Daejeon (Korea, Republic of)

    2013-09-15

    The rapid and accurate identification of biological agents is a critical step in the case of bio-terror and biological warfare attacks. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has been widely used for the identification of microorganisms. In this study, we describe a method for the rapid and accurate discrimination of Bacillus anthracis spores using MALDI-TOF MS. Our direct in-situ analysis of MALDI-TOF MS does not involve subsequent high-resolution mass analyses and sample preparation steps. This method allowed the detection of species-specific biomarkers from each Bacillus spores. Especially, B. anthracis spores had specific biomarker peaks at 2503, 3089, 3376, 6684, 6698, 6753, and 6840 m/z. Cluster and PCA analyses of the mass spectra of Bacillus spores revealed distinctively separated clusters and within-groups similarity. Therefore, we believe that this method is effective in the real-time identification of biological warfare agents such as B. anthracis as well as other microorganisms in the field.

  16. Discrimination of Bacillus anthracis Spores by Direct in-situ Analysis of Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry

    International Nuclear Information System (INIS)

    Jeong, Youngsu; Lee, Jonghee; Kim, Seongsoo

    2013-01-01

    The rapid and accurate identification of biological agents is a critical step in the case of bio-terror and biological warfare attacks. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has been widely used for the identification of microorganisms. In this study, we describe a method for the rapid and accurate discrimination of Bacillus anthracis spores using MALDI-TOF MS. Our direct in-situ analysis of MALDI-TOF MS does not involve subsequent high-resolution mass analyses and sample preparation steps. This method allowed the detection of species-specific biomarkers from each Bacillus spores. Especially, B. anthracis spores had specific biomarker peaks at 2503, 3089, 3376, 6684, 6698, 6753, and 6840 m/z. Cluster and PCA analyses of the mass spectra of Bacillus spores revealed distinctively separated clusters and within-groups similarity. Therefore, we believe that this method is effective in the real-time identification of biological warfare agents such as B. anthracis as well as other microorganisms in the field

  17. Preconcentration procedure using in situ solvent formation microextraction in the presence of ionic liquid for cadmium determination in saline samples by flame atomic absorption spectrometry.

    Science.gov (United States)

    Mahpishanian, Shokouh; Shemirani, Farzaneh

    2010-07-15

    A simple in situ solvent formation microextraction methodology based on the application of ionic liquid (IL) as an extractant solvent and sodium hexafluorophosphate (NaPF(6)) as an ion-pairing agent was proposed for the preconcentration of trace levels of cadmium. In this method cadmium was complexed with O,O-diethyldithiophosphate (DDTP) and extracted into an ionic liquid phase. After phase separation, the enriched analyte in the final solution is determined by flame atomic absorption spectrometry (FAAS). ISFME is a simple and rapid method for extraction and preconcentration of metal ions from sample solutions containing a high concentration of salt. Some effective factors that influence the microextraction efficiency were investigated and optimized. Under the optimum experimental conditions, the limit of detection (3 s) and the enhancement factor were 0.07 microg L(-1) and 78, respectively. The relative standard deviation (R.S.D.) was obtained 2.42%. The accuracy of the method was confirmed by analyzing certified reference materials for trace elements in seawater (GBW (E) 080040 seawater). The proposed method was successfully applied for the determination of cadmium in water samples and food grade salts. Crown Copyright 2010. Published by Elsevier B.V. All rights reserved.

  18. Investigation on the biosolubilization of brown coal using pyrolysis-gas chromatography-mass spectrometry and in situ-alkylation with tetraethylammonium hydroxide (TEAH)

    Energy Technology Data Exchange (ETDEWEB)

    Goetz, G.K.E. [RWTH Aachen (Germany). Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle]|[Bonn Univ. (Germany). Inst. fuer Mikrobiologie und Biotechnologie; Frost, P.J.; Fakoussa, R.M. [Bonn Univ. (Germany). Inst. fuer Mikrobiologie und Biotechnologie

    1997-12-31

    Brown coal of the Lower Rhine basin has been used for the biosolubilization experiments using Lentimula edodes and Trametes versicolor. Studying the coal fractions and residues remaining after coal biosolubilization by pyrolysis-gas chromatography-mass spectromety using tetraethylammonium hydroxide (TEAH) at 610 C show significant alteration of coal`s organic matter. The assemblage of fatty acid esters released during the pyrolysis varies depending on the investigated coal fraction and the used fungi. Further, ethyl derivatives of aromatic ethers and acids as well as dicarbonic acid ethyl diesters gain an insight into the metabolism pathways of the biosolubilization process of brown coal. Therefore TEAH was used in these thermochemolysis experiments instead the more common tetramethylammonium hydroxide (TMAH). The reaction of TEAH with free hydroxyl and carboxyl groups yield the ethyl derivatives which can be easily identified and differentiated from their methyl homologues by mass spectrometry. In situ-alkylation with TEAH during thermochemolysis of native and biological altered geomacromolecules offers a differentiation between free hydroxyl groups and their methylated counterparts and substances, which are attached to humic substances via ester or ether bridges. (orig.)

  19. In situ flow cell for combined X-ray absorption spectroscopy, X-ray diffraction, and mass spectrometry at high photon energies under solar thermochemical looping conditions

    Science.gov (United States)

    Rothensteiner, Matthäus; Jenni, Joel; Emerich, Hermann; Bonk, Alexander; Vogt, Ulrich F.; van Bokhoven, Jeroen A.

    2017-08-01

    An in situ/operando flow cell for transmission mode X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD), and combined XAS/XRD measurements in a single experiment under the extreme conditions of two-step solar thermochemical looping for the dissociation of water and/or carbon dioxide was developed. The apparatus exposes materials to relevant conditions of both the auto-reduction and the oxidation sub-steps of the thermochemical cycle at ambient temperature up to 1773 K and enables determination of the composition of the effluent gases by online quadrupole mass spectrometry. The cell is based on a tube-in-tube design and is heated by means of a focusing infrared furnace. It was tested successfully for carbon dioxide splitting. In combined XAS/XRD experiments with an unfocused beam, XAS measurements were performed at the Ce K edge (40.4 keV) and XRD measurements at 64.8 keV and 55.9 keV. Furthermore, XRD measurements with a focused beam at 41.5 keV were carried out. Equimolar ceria-hafnia was auto-reduced in a flow of argon and chemically reduced in a flow of hydrogen/helium. Under reducing conditions, all cerium(iv) was converted to cerium(iii) and a cation-ordered pyrochlore-type structure was formed, which was not stable upon oxidation in a flow of carbon dioxide.

  20. The use of MCNP and gamma spectrometry in supporting the evaluation of NORM in Libyan oil pipeline scale

    Energy Technology Data Exchange (ETDEWEB)

    Habib, Ahmed S., E-mail: a.habib@surrey.ac.u [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH, Surrey (United Kingdom); Bradley, D.A.; Regan, P.H. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH, Surrey (United Kingdom); Shutt, A.L. [Centre for Radiation Chemical and Environmental Hazards (CRCE), Health Protection Agency (HPA), Chilton, Didcot, OX11 0RQ (United Kingdom)

    2010-07-21

    The accumulation of scales in production pipes is a common problem in the oil industry, reducing fluid flow and also leading to costly remedies and disposal issues. Typical materials found in such scale are sulphates and carbonates of calcium and barium, or iron sulphide. Radium arising from the uranium/thorium present in oil-bearing rock formations may replace the barium or calcium in these salts to form radium salts. This creates what is known as technologically enhanced naturally occurring radioactive material (TENORM or simply NORM). NORM is a serious environmental and health and safety issue arising from commercial oil and gas extraction operations. Whilst a good deal has been published on the characterisation and measurement of radioactive scales from offshore oil production, little information has been published regarding NORM associated with land-based facilities such as that of the Libyan oil industry. The ongoing investigation described in this paper concerns an assessment of NORM from a number of land based Libyan oil fields. A total of 27 pipe scale samples were collected from eight oil fields, from different locations in Libya. The dose rates, measured using a handheld survey meter positioned on sample surfaces, ranged from 0.1-27.3 {mu}Sv h{sup -1}. In the initial evaluations of the sample activity, use is being made of a portable HPGe based spectrometry system. To comply with the prevailing safety regulations of the University of Surrey, the samples are being counted in their original form, creating a need for correction of non-homogeneous sample geometries. To derive a detection efficiency based on the actual sample geometries, a technique has been developed using a Monte Carlo particle transport code (MCNPX). A preliminary activity determination has been performed using an HPGe portable detector system.

  1. The Mars Organic Molecule Analyser : in situ analysis of organic compounds on Mars by Gas Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Buch, Arnaud; Sternberg, Robert; Freissinet, Caroline; Pinnick, Veronika; Szopa, Cyril; Coll, Patrice; Geffroy-Rodier, Claude; Raulin, Francois; Goesmann, Fred

    The search for signs of past or present life is one of the primary goals of the future Mars exploratory missions. With this aim the Mars Organic Molecule Analyzer (MOMA) experiment of the ExoMars 2016-2018 next coming joint ESA/NASA mission is designed to perform the in situ analysis of exobiological organic molecules of exobiological interest in the Martian soil such as amino acids, carboxylic acids, nucleobases or polycyclic aromatic hydrocarbons (PAHs). With the aim to separate and detect organic compounds from Martian soil, US and European teams have respectively built an ion trap mass spectrometer and a gas chromatograph. The mass spectrometer prototype has been coupled with the gas chromatograph prototype which is able to work in standalone mode by using a TCD detector. A GC-MS compatible sample processing system (SPS) allowing the extraction and the chemical transformation of the organic compounds from the soil, within space compatible operating conditions, has also been devel-oped. The sample processing is performed in an oven, dedicated to the MOMA experiment containing the solid sample (50-100mg). The internal temperature of which can be ranged from 20 to 1000 C. The extraction step is achieved by using thermodesorption in the range of 100 to 300C for 5 to 20 min. Then, the chemical derivatization and/or thermochemolysis of the extracted compounds is performed directly on the soil with a mixture of MTBSTFA-DMF, TMAH or DMF-DMA solution when enantiomeric separation is required. By decreasing the polarity of the target molecules, this step allows their volatilization at a temperature below 250C without any chemical degradation. Once derivatized, the volatile target molecules are trapped in a cold and chemical trap and promptly desorbed into the gas chromatograph coupled with a mass spectrometer. Preliminary tests, performed on Martian analogue soils (Atacama), with the MOMA SPS-GC/MS experiment, allowed the detection of organic compounds such as amino and

  2. Evaluating airborne and ground based gamma spectrometry methods for detecting particulate radioactivity in the environment: a case study of Irish Sea beaches.

    Science.gov (United States)

    Cresswell, A J; Sanderson, D C W

    2012-10-15

    In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the public who may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75 m ground clearance and 120 kph speeds to demonstrate the absence of sources greater than 5 MBq (137)Cs within large areas (10-20 km(2)h(-1)), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15m whilst maintaining speeds covering 1-2 km(2) h(-1) can detect buried (137)Cs sources of 0.5MBq or greater activity. A survey design to detect 100 kBq (137)Cs sources at 10 cm depth has also been defined, requiring surveys at <15m ground clearance and <2 ms(-1) ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Committed effective dose determination in cereal flours by gamma-ray spectrometry; Determinacao das doses efetivas por ingestao de farinhas de cereais atraves da espectrometria de raios gama

    Energy Technology Data Exchange (ETDEWEB)

    Scheibel, Viviane

    2006-07-01

    The health impact from radionuclides ingestion of foodstuffs was evaluated by the committed effective doses determined in commercial samples of South-Brazilian cereal flours (soy, wheat, corn, manioc, rye, oat, barley and rice flour). The radioactivity traces of {sup 228}Th, {sup 228}Ra, {sup 226}Ra, {sup 40}K, {sup 7}Be and {sup 137}Cs were measured by gamma-ray spectrometry employing a 66% relative efficiency HPGe detector. The energy resolution for the 1332.46 keV line of {sup 60}Co was 2.03 keV. The committed effective doses were calculated with the activities analyzed in the present flour samples, the foodstuff rates of consumption (Brazilian Institute of Geography and Statistics) and the ingestion dose coefficients (International Commission of Radiological Protection). The reliability median activities were verified with {chi}{sup 2} tests, assuring the fittings quality. The highest concentration levels of {sup 228}Th and {sup 40}K were 3.5 {+-} 0.4 and 1469 {+-} 17 Bq.kg{sup -1} for soy flour, respectively, with 95% of confidence level. The lower limit of detection for {sup 137}Cs ranged from 0.04 to 0.4 Bq.kg{sup -1}. The highest committed effective dose was 0.36 {mu}Sv.y{sup -1} for {sup 228}Ra in manioc flour (adults). All committed effective doses determined at the present work were lower than the UNSCEAR limits of 140 {mu}Sv.y{sup -1} and much lower than the ICRP (1991) limits of 1 mSv.y{sup -1}, for general public. There are few literature references for natural and artificial radionuclides in foodstuffs and mainly for committed effective doses. This work brings the barley flour data, which is not present at the literature and {sup 7}Be data which is not encountered in foodstuffs at the literature, besides all the other flours data information about activities and committed effective doses. (author)

  4. Isotopic composition of uranium in U3O8 by neutron induced reactions utilizing thermal neutrons from critical facility and high resolution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Acharya, R.; Pujari, P.K.; Goel, Lokesh

    2015-01-01

    Uranium in oxide and metal forms is used as fuel material in nuclear power reactors. For chemical quality control, it is necessary to know the isotopic composition (IC) of uranium i.e., 235 U to 238 U atom ratio as well as 235 U atom % in addition to its total concentration. Uranium samples can be directly assayed by passive gamma ray spectrometry for obtaining IC by utilizing 185 keV (γ-ray abundance 57.2%) of 235 U and 1001 keV (γ-ray abundance 0.837%) of 234m Pa (decay product of 238 U). However, due to low abundance of 1001 keV, often it is not practiced to obtain IC by this method as it gives higher uncertainty even if higher mass of sample and counting time are used. IC of uranium can be determined using activity ratio of neutron induced fission product of 235 U to activation product of 238 U ( 239 Np). In the present work, authors have demonstrated methodologies for determination of IC of U as well as 235 U atom% in natural ( 235 U 0.715%) and low enriched uranium (LEU, 3-20 atom % of 235 U) samples of uranium oxide (U 3 O 8 ) by utilizing ratio of counts at 185 keV γ-ray or γ-rays of fission products with respect to 277 keV of 239 Np. Natural and enriched samples (about 25 mg) were neutron irradiated for 4 hours in graphite reflector position of AHWR Critical Facility (CF) using highly thermalized (>99.9% thermal component) neutron flux (∼10 7 cm -2 s -1 )

  5. Development of an analytical model for the determination of 60Co in aqueous samples by atomic absorption and gamma spectrometry techniques

    International Nuclear Information System (INIS)

    Solis A, N. A.

    2015-01-01

    The applications of the nuclear energy in industry and medicine generate radioactive wastes that must be isolated and confined in order to limit its spread in the biosphere. These types of wastes are generated in hospitals, industry, research centers and nuclear power plants (during de fuel cycle). The radioactive elements (radionuclides) cannot be destroyed by any known method, either chemical or mechanical. Its final destruction is produced by radioactive decay, which makes them stable isotopes, or nuclear transmutation being bombarded with atomic particles. Consequently, the radioactive waste management is to control the radioactive discharges and reduce to tolerable limits, eliminating of effluents and wastes the radionuclides of interest, concentrating them so they can be stored or evacuated so that later not appear in dangerous concentration in the biosphere. In Mexico, the main generators of radioactive wastes are the nuclear power plant of Laguna Verde in Veracruz, Hospitals of the public and private sector, in addition Instituto Nacional de Investigaciones Nucleares (ININ) some institutes and facilities of the UNAM and Instituto Politecnico Nacional (IPN) and industries among others. The aqueous radioactive wastes, particularly those from the nuclear power plants contain traces of cobalt-60. Currently there is no model or analytical technique for the separation of this radionuclide, so it became necessary to develop an analytical model for separation and facilitate their disposal. In this paper was shown that atomic absorption and gamma spectrometry techniques can separate the active concentration of the inactive, which is important because the total concentration can be associated through direct relationships with the wear of metal parts of the nuclear reactor, since the metal alloys of the same reactor containing a fraction of cobalt. Also this analytical and mathematical model that can be reproducible and applicable to full sets of samples and that this

  6. In-situ determination of cross-over point for overcoming plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry

    International Nuclear Information System (INIS)

    Chan, George C.-Y.; Hieftje, Gary M.

    2008-01-01

    A novel method is described for overcoming plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry (ICP-AES). The method is based on measurement of the vertically resolved atomic emission of analyte within the plasma and therefore requires the addition of no reagents to the sample solution or to the plasma. Plasma-related matrix effects enhance analyte emission intensity low in the plasma but depress the same emission signal at higher positions. Such bipolar behavior is true for all emission lines and matrices that induce plasma-related interferences. The transition where the enhancement is balanced by the depression (the so-called cross-over point) results in a spatial region with no apparent matrix effects. Although it would be desirable always to perform determinations at this cross-over point, its location varies between analytes and from matrix to matrix, so it would have to be found separately for every analyte and for every sample. Here, a novel approach is developed for the in-situ determination of the location of this cross-over point. It was found that the location of the cross-over point is practically invariant for a particular analyte emission line when the concentration of the matrix was varied. As a result, it is possible to determine in-situ the location of the cross-over point for all analyte emission lines in a sample by means of a simple one-step sample dilution. When the original sample is diluted by a factor of 2 and the diluted sample is analyzed again, the extent of the matrix effect is identical (zero) between the original sample and the diluted sample at one and only one location - the cross-over point. This novel method was verified with several single-element matrices (0.05 M Na, Ca, Ba and La) and some mixed-element matrices (mixtures of Na-Ca, Ca-Ba, and a plant-sample digest). The inaccuracy in emission intensity due to the matrix effect could be as large as - 30% for conventional measurements in the

  7. In-Situ Sampling Analysis of a Jupiter Trojan Asteroid by High Resolution Mass Spectrometry in the Solar Power Sail Mission

    Science.gov (United States)

    Kebukawa, Y.; Aoki, J.; Ito, M.; Kawai, Y.; Okada, T.; Matsumoto, J.; Yano, H.; Yurimoto, H.; Terada, K.; Toyoda, M.; Yabuta, H.; Nakamura, R.; Cottin, H.; Grand, N.; Mori, O.

    2017-12-01

    The Solar Power Sail (SPS) mission is one of candidates for the upcoming strategic middle-class space exploration to demonstrate the first outer Solar System journey of Japan. The mission concept includes in-situ sampling analysis of the surface and subsurface (up to 1 m) materials of a Jupiter Trojan asteroid using high resolution mass spectrometry (HRMS). The candidates for the HRMS are multi-turn time-of-flight mass spectrometer (MULTUM) type and Cosmorbitrap type. We plan to analyze isotopic and elemental compositions of volatile materials from organic matter, hydrated minerals, and ice (if any), in order to understand origin and evolution of the Jupiter Trojan asteroids. It will provide insights into planet formation/migration theories, evolution and distribution of volatiles in the Solar System, and missing link between asteroids and comets on evolutional. The HRMS system allows to measure H, N, C, O isotopic compositions and elemental compositions of molecules prepared by various pre-MS procedures including stepwise heating up to 600ºC, gas chromatography (GC), and high-temperature pyrolysis with catalyst to decompose the samples into simple gaseous molecules (e.g., H2, CO, and N2) for isotopic ratio analysis. The required mass resolution should be at least 30,000 for analyzing isotopic ratios for simple gaseous molecules. For elemental compositions, mass accuracy of 10 ppm is required to determine elemental compositions for molecules with m/z up to 300 (as well as compound specific isotopic compositions for smaller molecules). Our planned analytical sequences consist of three runs for both surface and subsurface samples. In addition, `sniff mode' which simply introduces environmental gaseous molecules into a HRMS will be done by the system.

  8. Iron species determination by task-specific ionic liquid-based in situ solvent formation dispersive liquid-liquid microextraction combined with flame atomic absorption spectrometry.

    Science.gov (United States)

    Sadeghi, Susan; Ashoori, Vahid

    2017-10-01

    The task-specific ionic liquid (TSIL) of 1-ethyl-3-methylimidazolium bromide functionalized with 8-hydroxyquinoline was used as a chelating agent and extracting solvent for dispersive liquid-liquid microextraction and subsequent determination of Fe(III) by flame atomic absorption spectrometry. The in situ solvent formation of TSIL using KPF 6 provided the desired water-immiscible ionic liquid. The total Fe concentration could be determined after pre-oxidation of Fe(II) to Fe(III). Various factors affecting the proposed extraction procedure were optimized. The proposed analytical conditions were: sample pH 5, TSIL amount 0.3% (w/v), KPF 6 amount 0.15% (w/v), anti-sticking 0.1% (w/v) and salt concentration 5% (w/v). Under optimal conditions, the linear dynamic ranges for Fe(III) and total Fe were 20-80 and 20-110 ng mL -1 , respectively, with a detection limit of 6.9 ng mL -1 for Fe(III) and relative standard deviation of 2.2%. The proposed method was successfully applied to the determination of trace Fe(III) in water (underground, tap, refined water and artificial sea water) and beverage (apple, tomato, and tea) samples. The developed method offers advantages such as simplicity, ease of operation, and extraction of Fe(III) from aqueous solutions without the use of organic solvent. It was successfully applied for iron speciation in different real samples. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  9. Development of a methodology for the detection of Ra226 in large volumes of water by gamma spectrometry; modification and validation of the method for detection and quantification of Ra226 in small volumes of water by alpha spectrometry, used by the Centro de Investigacion en Ciencias Atomicas, Nucleares y Moleculares (CICANUM, UCR)

    International Nuclear Information System (INIS)

    Molina Porras, Arnold

    2011-01-01

    The test method has been validated for quantifying the specific activity of Ra 226 in water alpha spectrometry. The CICANUM has used this method as part of the proposed harmonization of methods ARCAL (IAEA). The method is based on a first separation and preconcentration of Ra 226 by coprecipitation and subsequent MnO 2 micro precipitation as Ba (Ra) SO 4 . Samples were prepared and then was performed the counting by alpha spectrometry. A methodology of radio sampling for large volumes of water was tested in parallel, using acrylic fibers impregnated with manganese oxide (IV) to determine the amount of Ra 226 present by gamma spectrometry. Small-scale tests, have determined that the best way to prepare the fiber is the reference method found in the literature and using the oven at 60 degrees Celsius. (author) [es

  10. Analysis of expressed sequence tags from a single wheat cultivar facilitates interpretation of tandem mass spectrometry data and discrimination of gamma gliadin proteins that may play different functional roles in flour

    Directory of Open Access Journals (Sweden)

    Altenbach Susan B

    2010-01-01

    Full Text Available Abstract Background The gamma gliadins are a complex group of proteins that together with other gluten proteins determine the functional properties of wheat flour. The proteins have unusually high levels of glutamine and proline and contain large regions of repetitive sequences. While most gamma gliadins are monomeric proteins containing eight conserved cysteine residues, some contain an additional cysteine residue that enables them to be linked with other gluten proteins into large polymers that are critical for flour quality. The ability to differentiate among the gamma gliadins is important for studies of wheat flour quality because proteins with similar sequences can have different effects on functional properties. Results The complement of gamma gliadin genes expressed in the wheat cultivar Butte 86 was evaluated by analyzing publicly available expressed sequence tag (EST data. Eleven contigs were assembled from 153 Butte 86 ESTs. Nine of the contigs encoded full-length proteins and four of the proteins contained nine cysteine residues. Only one of the encoded proteins was a perfect match with a sequence reported in NCBI. Contigs from four different publicly available EST assemblies encoded proteins that were perfect matches with some, but not all, of the Butte 86 gamma gliadins and the complement of identical proteins was different for each assembly. A specialized database that included the sequences of Butte 86 gamma gliadins was constructed for identification of flour proteins by tandem mass spectrometry (MS/MS. In a pilot experiment, proteins corresponding to six Butte 86 gamma gliadin contigs were distinguished by MS/MS, including one containing the extra cysteine residue. Two other proteins were identified as one of two closely related Butte 86 proteins but could not be distinguished unequivocally. Unique peptide tags specific for Butte 86 gamma gliadins are reported. Conclusions Inclusion of cultivar-specific gamma gliadin sequences

  11. A gamma-gamma coincidence spectrometric method for rapid characterization of uranium isotopic fingerprints

    International Nuclear Information System (INIS)

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

    2011-01-01

    This paper reports on initial efforts for uranium isotopic analysis using gamma-rays and X-ray fluorescence coincidence. In this study, a gamma-gamma coincidence spectrometry was developed. The spectrometry consists of two NaI(Tl) scintillators and XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The developed spectrometry was optimized according to the considerations of output count rate and gamma peak energy resolution. It has been demonstrated that the spectrometry provides an effective method of assessing the content of uranium isotopes for nuclear materials. The main advantages of this approach over the conventional gamma spectrometry include the fact that 235 U enrichment can be graphically characterized by its unique coincidence 'fingerprints'. The method could be further developed for fast uranium isotope verification with an established gamma-gamma coincidence spectral imaging library by various nuclear materials. (author)

  12. Calibration and study of the measurement capabilities of real-time gamma spectrometry equipment, developed for the renewal of the network of automatic stations for environmental radiological surveillance of the Generalitat de Catalunya

    International Nuclear Information System (INIS)

    Casanovas, R.; Prieto, E.; Salvado, M.

    2013-01-01

    The renewal of the automatic environmental radiation surveillance network of the Gereralitat of Catalunya has been carried out through the development and implementation of gamma-spectrometry-based equipment. The monitors use scintillation cristals, either NaI(Tl) or LaBr 3 (Ce) and currently, there are 3 types of equipment: water radioactivity monitors, aerosols on a particulate filter monitors and direct measurement monitors. In this paper, we expose the basic features of its operation, the details of their calibration and the minimum detectable activity concentrations for some isotopes

  13. Calibration and study of the measurement capabilities of real-time gamma spectrometry equipment developed for the renewal of the network of stations automatic monitoring environmental radiation of the Generalitat of Catalunya

    International Nuclear Information System (INIS)

    Casanovas, R.; Prieto, E.; Salvado, M.

    2014-01-01

    The renewal of the automatic environmental radiation surveillance network of the Generalitat of Catalunya has been carried out through the development and implementation of gamma-spectrometry-based equipment. the monitors use scintillation crystals, either Na(TI) or LaBr 3 (Ce) and currently, there are 3 types of equipment water radioactivity monitors, aerosols on a particulate filter monitors and direct measurement monitors. In this paper, we expose the basic features of its operation, the details of their calibration and the minimum detectable activity concentration for some isotopes. (Author)

  14. In-Situ Assay Of Transuranic Radionuclides In The Vadose Zone Using High-Resolution Spectral Gamma Logging - A Hanford Case Study

    International Nuclear Information System (INIS)

    Rohay, V.J.; Henwood, P.; McCain, R.

    2009-01-01

    High-resolution spectral gamma logging in steel-cased boreholes is used to detect and quantify transuranic radionuclides in the subsurface. Pu-239, Pu-241, Am-241, and Np-237 are identified based on characteristic decay gammas. Typical minimum detectable levels are on the order of 20 to 40 nCi/g. In intervals of high transuranic concentrations, gamma rays from other sources may complicate analysis and interpretation. Gamma rays detected in the borehole may originate from three sources: decay of the parent transuranic radionuclide or a daughter; alpha interactions; and interactions with neutrons resulting from either spontaneous fission or alpha particle interactions.

  15. In-situ gammaspectrometry intercomparison exercise in Salzburg/Austria

    International Nuclear Information System (INIS)

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

    1996-01-01

    In-situ gamma-spectrometry has become a useful method of assessing the nuclide concentrations of man-made and natural gamma-emitters in the soil. For the quality assurance of the measurements, periodically conducted intercomparison exercises are essential. Therefore exercises were organized in different European countries since 1990, the last one was conducted in Salzburg /Austria in September 1994. The participation of 24 measurement-teams from all over Europe emphasizes the importance of the intercomparison. Salzburg was selected because the Province of Salzburg /Austria was among the most heavily contaminated regions outside the former USSR by the Chernobyl fallout. Two different typical sites were selected for the measurements: Site 1 was inside the urban area of Salzburg on intensively used grassland which had not been tilled since the deposition of the fallout. This site is representative for intensively used agricultural regions in the Province of Salzburg. Site 2 was in the mountainous regions of the Hohe Tauern at an elevated altitude of 1600 m, representing the agricultural soil- and contamination conditions of the Alpine regions in the Tauern. The two sites differ significantly in terms of soil characteristics, a crucial parameter for the evaluation of in-situ gamma-spectra. The participants used different approaches for the evaluation of the gamma-spectra in terms of considering the depth distribution. In the paper the results from the 24 European teams are presented. (author)

  16. Application of in situ measurement for site remediation and final status survey of decommissioning KRR site

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sang Bum; Nam, Jong Soo; Choi, Yong Suk; Seo, Bum Kyoung; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-06-15

    In situ gamma spectrometry has been used to measure environmental radiation, assumptions are usually made about the depth distribution of the radionuclides of interest in the soil. The main limitation of in situ gamma spectrometry lies in determining the depth distribution of radionuclides. The objective of this study is to develop a method for subsurface characterization by in situ measurement. The peak to valley method based on the ratio of counting rate between the photoelectric peak and Compton region was applied to identify the depth distribution. The peak to valley method could be applied to establish the relation between the spectrally derived coefficients (Q) with relaxation mass per unit area (β) for various depth distribution in soil. The in situ measurement results were verified by MCNP simulation and calculated correlation equation. In order to compare the depth distributions and contamination levels in decommissioning KRR site, in situ measurement and sampling results were compared. The in situ measurement results and MCNP simulation results show a good correlation for laboratory measurement. The simulation relationship between Q and source burial for the source layers have exponential relationship for a variety depth distributions. We applied the peak to valley method to contaminated decommissioning KRR site to determine a depth distribution and initial activity without sampling. The observed results has a good correlation, relative error between in situ measurement with sampling result is around 7% for depth distribution and 4% for initial activity. In this study, the vertical activity distribution and initial activity of {sup 137}Cs could be identifying directly through in situ measurement. Therefore, the peak to valley method demonstrated good potential for assessment of the residual radioactivity for site remediation in decommissioning and contaminated site.

  17. Determination of plutonium isotopic abundances by gamma-ray spectrometry. Interim report on the status of methods and techniques developed by the Lawrence Livermore Laboratory

    International Nuclear Information System (INIS)

    Gunnink, R.

    1980-03-01

    This report presents an overview of methods and techniques developed by the Lawrence Livermore Laboratory for determining plutonium isotopic abundances from gamma-ray spectra that have been measured with germanium detectors. The methodology of fitting the spectral features includes discussions of algorithms for gamma-ray and x-ray peak shape fitting and generation of response spectra profiles characteristic of specific isotopes. Applications of the techniques developed at government, commercial, and Japanese reprocessing plants are described. Current development of the methodology for the nondestructive analysis of samples containing nondescript solid materials is also presented

  18. 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)

  19. Simultaneous determination of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry INa(Ti), in solid samples.; Determinacion de U (Natural), Th (Natural) y Ra-226 en diversos materiales, mediante espectrometria con INa (TI)

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-07-01

    A method has been developed to determine activities of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry. The measurement system has been calibrated using standards specially prepared at the laboratory. It is necessary to assume secular equilibrium in the samples, between Ra-226 and Th-232 and its daughters nuclides, and between U-238 and its immediate daughter Th-234, as the photo peaks measured are those of the daughters. The results obtained indicate that this method can of ter replace the radiochemical techniques used to measure activities in this type of sample. The method has been successfully used to determine these natural isotopes in samples from uranium mills. (Author) 9 refs.

  20. In situ derivatization-ultrasound-assisted dispersive liquid-liquid microextraction for the determination of neurotransmitters in Parkinson's rat brain microdialysates by ultra high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    He, Yongrui; Zhao, Xian-En; Zhu, Shuyun; Wei, Na; Sun, Jing; Zhou, Yubi; Liu, Shu; Liu, Zhiqiang; Chen, Guang; Suo, Yourui; You, Jinmao

    2016-08-05

    Simultaneous monitoring of several neurotransmitters (NTs) linked to Parkinson's disease (PD) has important scientific significance for PD related pathology, pharmacology and drug screening. A new simple, fast and sensitive analytical method, based on in situ derivatization-ultrasound-assisted dispersive liquid-liquid microextraction (in situ DUADLLME) in a single step, has been proposed for the quantitative determination of catecholamines and their biosynthesis precursors and metabolites in rat brain microdialysates. The method involved the rapid injection of the mixture of low toxic bromobenzene (extractant) and acetonitrile (dispersant), which containing commercial Lissamine rhodamine B sulfonyl chloride (LRSC) as derivatization reagent, into the aqueous phase of sample and buffer, and the following in situ DUADLLME procedure. After centrifugation, 50μL of the sedimented phase (bromobenzene) was directly injected for ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) detection in multiple reaction monitoring (MRM) mode. This interesting combination brought the advantages of speediness, simpleness, low matrix effects and high sensitivity in an effective way. Parameters of in situ DUADLLME and UHPLC-MS/MS conditions were all optimized in detail. The optimum conditions of in situ DUADLLME were found to be 30μL of microdialysates, 150μL of acetonitrile containing LRSC, 50μL of bromobenzene and 800μL of NaHCO3-Na2CO3 buffer (pH 10.5) for 3.0min at 37°C. Under the optimized conditions, good linearity was observed with LODs (S/N>3) and LOQs (S/N>10) of LRSC derivatized-NTs in the range of 0.002-0.004 and 0.007-0.015 nmol/L, respectively. It also brought good precision (3.2-12.8%, peak area CVs%), accuracy (94.2-108.6%), recovery (94.5-105.5%) and stability (3.8-8.1%, peak area CVs%) results. Moreover, LRSC derivatization significantly improved chromatographic resolution and MS detection sensitivity of NTs when compared with the

  1. Determination of burnup grade of fuel plates by gamma spectrometry; Determinacao do grau de queima em elementos combustiveis tipo placa por meio de espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Terremoto, Luis A.A.; Zeituni, Carlos A.; Perrotta, Jose A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Engenharia do Nucleo

    1999-11-01

    This work describes absolute burnup measurements on spent MTR fuel elements by means of non-destructive gamma-ray spectroscopy which correlates activities of radioactive fission products with the fissioned mass of {sup 235} U. Experiments based on such method were performed at the storage pool area of the IEA-R1 research reactor. The obtained results were compared with calculational ones based on neutronics. (author) 7 refs., 6 figs., 1 tab.; e-mail: laaterre at net.ipen.br

  2. Gamma gamma technology group

    Indian Academy of Sciences (India)

    The gamma gamma community are concerned that in the rush to prepare for the e+e− machine, allowance is not being made for a future upgrade of the photon linear collider. References. [1] ECFA/DESY Photon Collider Working Group: B Badelek et al, TESLA Technical. Design Report, Part VI, Chapter 1: Photon collider at ...

  3. Calibration of HPGe-HPGe coincidence spectrometer through performing standardisation of 125I activity by X-ray-gamma coincidence spectrometry using two HPGe detectors

    Science.gov (United States)

    Marković, Nikola; Roos, Per; Hou, Xiaolin; Nielsen, Sven Poul

    2018-02-01

    An X-ray-gamma coincidence measurement method for efficiency calibration of a HPGe-HPGe system, using the methodology for activity standardisation of 125I, has been developed. By taking one list-mode time-stamped measurement of the 125I source, six spectra were generated in post-processing: total spectra, coincidence spectra and energy gated coincidence spectra for each of the two detectors. The method provides enough observables for source activity to be determined without a prior knowledge of the detector efficiencies. In addition, once the source is calibrated in this way the same spectra can also be used to perform efficiency calibration of the individual detectors in the low energy range. This new methodology for source activity determination is an alternative to the already established X-ray-(X-ray, gamma) coincidence counting method; with two NaI(Tl) detectors and the sum-peak method using a single HPGe detector. When compared to the coincidence counting method using two NaI(Tl) detectors, the newly developed method displays improved energy resolution of HPGe detectors combined with measurement of only full peak areas, without the need for total efficiency determination. This enables activity determination even in presence of other gamma emitters in the sample. Standard coincidence counting with NaI(Tl) detectors provides lower uncertainties. The method has been used for calibration of a coincidence HPGe spectrometer in the low energy range of 125I and fine adjustments of a Monte Carlo model of the coincidence system.

  4. Assay of uranium in fused salt cake generated at the natural uranium metal fuel fabrication plants by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Kalsi, P.C.; Bhanu, A.U.; Sahoo, S.; Iyer, R.H.

    1986-01-01

    A passive gamma-ray spectroscopic method is employed for the assay of uranium in fused salt cake, a scrap produced at the natural uranium metal fuel fabrication plants. The method makes use of NaI(TI) detector coupled with a multichannel analyser. The 1 MeV gamma-ray of 238 U was used for the calibration. The calibration curve was made by counting synthetic mixtures made of U 3 O 8 powder, the heat treatment salt and iron in the form of fine powder. The uranium content in these synthetic mixtures was kept in the range of 1-11 per cent. 23 lots of the fused salt cake taken from three different batches of the salt cake were then analysed by this method. The uranium content of fused salt cake was found to be in the range of 1.70-11.43 per cent. To compare the gamma spectrometric results with a completely independent method, chemical analysis of all the fused salt cakes were also carried out. The NDA results were found to agree within ± 17 per cent with the chemical analysis results. (author)

  5. Future planetary X-ray and gamma-ray remote sensing system and in situ requirements for room temperature solid state detectors

    CERN Document Server

    Trombka, J I; Starr, R; Clark, P E; Floyd, S R

    1999-01-01

    X-Ray and gamma-ray remote sensing observations find important applications in the study of the development of the planets. Orbital measurements can be carried out on solar-system bodies whose atmospheres and trapped radiation environments do not interfere significantly with the emissions. Elemental compositions can be inferred from observations of these line emissions. Future planetary missions also will involve landing both stationery and roving probes on planetary surfaces. Both X-ray and gamma-ray spectrometers will be used for performing elemental analysis of surface samples. These future planetary missions will impose a number of constraints: the flight instruments must be significantly reduced in weight from those previously flown; for many missions, gravity assist will be required, greatly increasing mission duration, resulting in the passage of several years before the first scientific measurement of a solar system body. The detector systems must operate reliably after years of cosmic-ray irradiation...

  6. The efficiency calibration and development of environmental correction factors for an in situ high-resolution gamma spectroscopy well logging system

    International Nuclear Information System (INIS)

    Giles, J.R.

    1996-05-01

    A Gamma Spectroscopy Logging System (GSLS) has been developed to study sub-surface radionuclide contamination. Absolute efficiency calibration of the GSLS was performed using simple cylindrical borehole geometry. The calibration source incorporated naturally occurring radioactive material (NORM) that emitted photons ranging from 186-keV to 2,614-keV. More complex borehole geometries were modeled using commercially available shielding software. A linear relationship was found between increasing source thickness and relative photon fluence rates at the detector. Examination of varying porosity and moisture content showed that as porosity increases, relative photon fluence rates increase linearly for all energies. Attenuation effects due to iron, water, PVC, and concrete cylindrical shields were found to agree with previous studies. Regression analyses produced energy-dependent equations for efficiency corrections applicable to spectral gamma-ray well logs collected under non-standard borehole conditions

  7. Calibration, field-testing, and error analysis of a gamma-ray probe for in situ measurement of dry bulk density

    International Nuclear Information System (INIS)

    Bertuzzi, P.; Bruckler, L.; Gabilly, Y.; Gaudu, J.C.

    1987-01-01

    This paper describes a new gamma-ray probe for measuring dry bulk density in the field. This equipment can be used with three different tube spacings (15, 20 and 30 cm). Calibration procedures and local error analyses are proposed for two cases: (1) for the case where the access tubes are parallel, calibration equations are given for three tube spacings. The linear correlation coefficient obtained in the laboratory is satisfactory (0.999), and a local error analysis shows that the standard deviation in the measured dry bulk density is small (+/- 0.02 g/cm 3 ); (2) when the access tubes are not parallel, a new calibration procedure is presented that accounts for and corrects measurement bias due to the deviating probe spacing. The standard deviation associated with the measured dry bulk density is greater (+/- 0.05 g/cm 3 ), but the measurements themselves are regarded as unbiased. After comparisons of core samplings and gamma-ray probe measurements, a field validation of the gamma-ray measurements is presented. Field validation was carried out on a variety of soils (clay, clay loam, loam, and silty clay loam), using gravimetric water contents that varied from 0.11 0.27 and dry bulk densities ranging from 1.30-1.80 g°cm -3 . Finally, an example of dry bulk density field variability is shown, and the spatial variability is analyzed in regard to the measurement errors

  8. Software for nuclear spectrometry

    International Nuclear Information System (INIS)

    1998-10-01

    The Advisory Group Meeting (AGM) on Software for Nuclear Spectrometry was dedicated to review the present status of software for nuclear spectrometry and to advise on future activities in this field. Because similar AGM and consultant's meetings had been held in the past; together with an attempt to get more streamlined, this AGM was devoted to the specific field of software for gamma ray spectrometry. Nevertheless, many of the issues discussed and the recommendations made are of general concern for any software on nuclear spectrometry. The report is organized by sections. The 'Summary' gives conclusions and recommendations adopted at the AGM. These conclusions and recommendations resulted from the discussions held during and after presentations of the scientific and technical papers. These papers are reported here in their integral form in the following Sections

  9. Determination of basic degradation products of chemical warfare agents in water using hollow fibre-protected liquid-phase microextraction with in-situ derivatisation followed by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Lee, Hoi Sim Nancy; Sng, Mui Tiang; Basheer, Chanbasha; Lee, Hian Kee

    2008-07-04

    Hollow fibre-protected liquid-phase microextraction (HF-LPME) together with gas chromatography-mass spectrometry was, for the first time, investigated for the in-situ derivatisation and analysis of basic degradation products of chemical warfare agents in water samples. The degradation products studied were those of nerve and blister agents, and a psychotomimetic agent. Extractions with in-situ derivatisation were successfully performed using a mixture of solvent and derivatising agent. The protection of the moisture-sensitive derivatising agent was afforded by the hydrophobic hollow fibre. Parameters such as type of derivatising agent, extraction solvent, pH, salt concentration, stirring speed and extraction time were optimised using spiked deionised water samples. The linear range established was between 0.05 and 25 microg ml(-1) depending on analyte, with squared regression coefficients ranging from 0.9959 to 0.9996. Relative standard deviations (RSDs) ranged from 6% to 10%. As comparison, solid-phase microextraction (SPME) was also evaluated and extraction conditions such as pH, salt concentration, stirring speed and extraction time were optimised. This work also represented the first report of such an in-situ derivatisation approach for SPME of basic analytes. The linear range established was between 0.5 and 25 microg ml(-1) depending on analyte, with squared regression coefficients ranging from 0.9946 to 0.9998. RSDs ranged from 5% to 22%. The limits of detection of HF-LPME (0.04-0.36 microg l(-1)) showed improvement over those of SPME (0.06-0.77 microg l(-1)).

  10. In situ analysis of plant tissue underivatized carbohydrates and on-probe enzymatic degraded starch by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry by using carbon nanotubes as matrix.

    Science.gov (United States)

    Gholipour, Yousef; Nonami, Hiroshi; Erra-Balsells, Rosa

    2008-12-15

    Underivatized carbohydrates of tulip bulb and leaf tissues were characterized in situ by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) by using carbon nanotubes (CNTs) as matrix. Two sample preparation methods--(i) depositing CNTs on the fresh tissue slices placed on the probe and (ii) locating semitransparent tissues on a dried layer of CNTs on the probe--were examined. Furthermore, practicability of in situ starch analysis by MALDI-TOF MS was examined by detection of glucose originated from on-probe amyloglucosidase-catalyzed degradation of starch on the tissue surface. Besides, CNTs could efficiently desorb/ionize natural mono-, di-, and oligosaccharides extracted from tulip bulb tissues as well as glucose resulting from starch enzymatic degradation in vitro. These results were compared with those obtained by in situ MALDI-TOF MS analysis of similar tissues. Positive ion mode showed superior signal reproducibility. CNTs deposited under semitransparent tissue could also desorb/ionize neutral carbohydrates, leading to nearly complete elimination of matrix cluster signals but with an increase in tissue-originated signals. Furthermore, several experiments were carried out to compare the efficiency of 2,5-dihydroxybenzoic acid, nor-harmane, alpha-cyano-4-hydroxycinnamic acid, and CNTs as matrices for MALDI of neutral carbohydrates from the intact plant tissue surface and for enzymatic tissue starch degradation; these results are discussed in brief. Among matrices studied, the lowest laser power was needed to acquire carbohydrate signals with high signal-to-noise ratio and resolution when CNTs were used.

  11. Soil gamma ray spectrometry of the Buquira river basin, SP, Brazil; Gamametria de solos da bacia do rio Buquira, SP, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, Alice

    2002-12-01

    Natural radioactivity found in rocks and its evaluation been frequently used for studies of environmental geochemistry, particularly those of detection and control of pollutants and the consequent changes in environment after antropic interferences. In this work natural radioactivity in forty nine soil samples in the basin of Buquira river, at the Northeast region of Sao Paulo State, has been analysed and measured with a Ge-HP gamma ray spectrometer. A table with the most relevant results found in rocks is shown and discussed. (author)

  12. Airborne gamma ray spectrometry in certain areas of the Islamic Republic of Iran and its results - correlation to the other usages

    International Nuclear Information System (INIS)

    Soleimani, G.; Yegani, F.S.

    1997-01-01

    Airborne survey can be utilized as a multipurpose data in different fields such as exploration, health physics, environmental studies and so on. The well known advantages of airborne survey include rapidity, more extent of surveyed area, the possibility of application in unaccessible regions where no other methods can be utilized. More than one third of Iran territory i.e. about 600,000 km 2 has been surveyed by magnetic and spectral gamma ray airborne. This survey is one of the largest and most highly specified survey of its type ever attempted. Extremely large quantities of data were generated during the survey which can be used as a baseline information. (author)

  13. Determination of glutamic acid and gamma-aminobutyric acid in Ringer's solution without desalination at the femtomole level by gas chromatography chemical ionization mass spectrometry.

    Science.gov (United States)

    Murayama, K; Shindo, N; Mineki, R; Ohta, K

    1981-04-01

    For the quantification of glutamic acid in Ringer's solution, pentafluoropropionic methyl ester was the most sensitive derivative. The detectable concentration was 0.01 microM glutamic acid in Ringer's solution; the amount of the preparation was 1 pmol and the injection into a gas chromatograph mass spectrometer was 10 fmol. For the quantification of gamma-aminobutyric acid in Ringer's solution, the trifluoroacetal-hexafluoropropionyl ester was quantification of gamma-aminobutyric acid in Ringer's solution, the trifluoroacetal-hexafluoropropionyl ester was detectable at a concentration of 0.01 microM. Ringer's salts facilitated acylation in the order heptafluorobutyric anhydride greater than pentafluoropropionic anhydride greater than trifluoroacetic anhydride. The effect depended on esterification of carboxy groups in the order methyl ester greater than hexafluoropropionyl ester greater than butyl ester. Sodium carbonate, sodium acetate and sodium citrate also facilitated acylation with pentafluoroproionic anhydride, while sodium phosphate inhibited the acylation and sodium sulfate inhibited it slightly. The pentafluoropropionic methyl ester of glutamic acid was stable for up to 10 days, when it was dissolved in acetone and stored at -18 degrees C.

  14. The results obtained by INR-Pitesti to an international in-situ intercomparison exercise

    International Nuclear Information System (INIS)

    Dobrin, Relu; Dulama, Cristian; Toma, Alexandru

    2008-01-01

    Full text: The determination of soil contamination, dose rate measurements and in-situ gamma spectrometry are well established and widely used measurement procedures, especially after large scale nuclear incidents. To support decision makers and first responders with a more comprehensive and accurate overview immediately after a large scale nuclear or radiological emergency, as releases from a nuclear power plant or a terrorist attack with a dirty bomb, a fast and clear presentation of measurement data is indispensable. In 2007, the Austrian Research Centers GmbH - ARC (Seibersdorf) in cooperation with IAEA and the Austrian NBC Defense School organized an international measurement campaign, 'In-Situ Intercomparison Scenario' ISIS 2007, with the focus on In-Situ Gamma Spectrometry and Dose Rate Measurements in Emergency Situations. 56 teams from 25 countries, worldwide, took part to this exercise. The only Romanian team was 'CROWN'. The CROWN Laboratory is part of the Radiation Protection Laboratory of the Institute for Nuclear Research - Pitesti, certified for characterization of radioactive wastes and nuclear materials. The paper presents results obtained during different tasks of the exercise: 'Dose rate mapping'; 'Localization - Drive by'; 'Simulation of a contamination'; 'Identification Shielded; 'Identification/Quantification'; 'Buried sources; 'Environmental measurement'. (authors)

  15. Xenon Spectral Gamma Penetrometer Probe Characterization and Calibration

    National Research Council Canada - National Science Library

    Ballard, John

    2004-01-01

    .... A Site Characterization and Analysis Penetrometer System (SCAPS) spectral gamma penetrometer probe was designed using newly developed small-diameter high-pressure xenon gas gamma ray detector technology for the in situ speciation (identification...

  16. Burn-Up Determination by High Resolution Gamma Spectrometry: Spectra from Slightly-Irradiated Uranium and Plutonium between 400-830 keV

    International Nuclear Information System (INIS)

    Forsyth, R.S.; Ronqvist, N.

    1966-08-01

    Previously published studies of the short-cooled fission product spectra of irradiated uranium have been severely restricted by the poor energy resolution of the sodium iodide detectors used. In this report are presented fission product spectra of irradiated uranium and plutonium obtained by means of a lithium-drifted germanium detector. The resolved gamma peaks have been assigned to various fission products by correlation of measured energy and half-life values with published data. By simultaneous study of the spectra of two irradiated mixtures of plutonium and uranium, the possibility of using the activities of Ru-103 and Ru-106 as a measure of the relative fission rate in U-235 and Pu-239 has been briefly examined

  17. Burn-Up Determination by High Resolution Gamma Spectrometry: Spectra from Slightly-Irradiated Uranium and Plutonium between 400-830 keV

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, R.S.; Ronqvist, N.

    1966-08-15

    Previously published studies of the short-cooled fission product spectra of irradiated uranium have been severely restricted by the poor energy resolution of the sodium iodide detectors used. In this report are presented fission product spectra of irradiated uranium and plutonium obtained by means of a lithium-drifted germanium detector. The resolved gamma peaks have been assigned to various fission products by correlation of measured energy and half-life values with published data. By simultaneous study of the spectra of two irradiated mixtures of plutonium and uranium, the possibility of using the activities of Ru-103 and Ru-106 as a measure of the relative fission rate in U-235 and Pu-239 has been briefly examined.

  18. Assessment of the uranium potential of the Jurassic volcanism (Bahía Laura and El Quemado Complexes), Province of Santa Cruz, using ground-borne gamma-ray spectrometry and rock geochemistry

    International Nuclear Information System (INIS)

    Kleinman, L.E.; Maloberti, A.L.; Gayone, M.R.; Kaufmann, C.; Sruoga, P.

    2013-01-01

    Radiometric surveys are a rapid tool to measure uranium (U), thorium (Th) and potassium (K) concentrations in rocks and are very useful in the exploration for radioactive minerals. The distribution of uranium in Jurassic volcanic rocks of the province of Santa Cruz is evaluated in this work using ground gamma-ray spectrometry and rock geochemistry in order to assess its potential to form uranium deposits. Five areas were selected, which had some previous data of high radiometric values and detailed geological information. Measurements were carried out with a portable gamma-ray spectrometer (Exploranium-GR 320®) in andesites, ignimbrites, rhyolites, silicified areas, ash-fall tuffs and lacustrine sediments corresponding to the Bahía Laura and to El Quemado complexes. The results were similar in the five surveyed areas: radiometric concentrations show good positive correlations with chemical composition of the studied rocks for both K and Th, and a relatively poorer correlation for U. Different processes such as magmatic differentiation, vapor phase crystallization, hydrothermal alteration and supergene alteration are reflected in the distribution of these elements. U concentrations increase in the more glassy rocks, in areas with hydrothermal silicification, and in fracture zones, features that should be considered in future surveys. The calkalkaline composition and arc-signatures of the Jurassic magmatism are not the most favorable for uranium enrichment and for concentration of significant mineralizations. However, the extensional tectonic setting; the occurrence of calderas with facies slightly enriched in U and Th, in addition to hydrothermal activity are positive factors for U exploration. (authors) [es

  19. Aerial gamma spectrometry of the uranium province of Lagoa Real (Caetite, BA, Brazil): go environmental aspects and distribution of the absorbed dose in the air

    International Nuclear Information System (INIS)

    Santos, Esau Francisco Sena

    2006-01-01

    In the present study, it was analyzed the surface concentrations of the natural radioelements K, U and Th, as well as the absorbed dose rate in air caused by gamma radiation from the Lagoa Real uranium province, which is located at the center southern portion of Bahia State and comprises an area of approximately 4.600 Km 2 . Data from the airborne gamma ray spectrometric survey of the region (Sao Timoeo Project) carried out in 1979, was used in this study. Besides, recent data of U, Th and absorbed dose rates from the Environmental Monitoring Program of the uranium concentration plant (URA), operated in the region by the Brazilian Nuclear Industries (INB), were used with the aim of inter compare the sampling points in the same geo referenced area. Imaging geo processing software's give support to frame maps of surface concentrations and ternary maps, as well as allow the integration of these with other themes (e.g. hydrology, geology, pedology) favouring the interpretation of geo environmental process from the radioactive cartography. Considering the whole study area, it was obtained the following mean values: absorbed dose rate in air (61,08 nGy.h -1 ), Potassium (1,65 % K) , Uranium (3,02 ppm eU) and thorium (18,26 ppm eTh). The geological unities bounding the uranium anomalies were placed in the areas characterized by the highest values of radioelements and, as expected, the major dose levels. The use of ternary maps coupled with the geology and hydrology allowed distinguishing the relationship between the surface distribution of natural radioelements and the geo environmental aspects, including the influence of the catchment in their transport and migration. (author)