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Sample records for geological samples neutron

  1. Applicability of neutron activation analysis to geological samples

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-03-01

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

  2. Applicability of neutron activation analysis to geological samples

    International Nuclear Information System (INIS)

    Ebihara, Mitsuru

    2003-01-01

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

  3. Effect of granulation of geological samples in neutron transport measurements

    International Nuclear Information System (INIS)

    Woznicka, Urszula; Drozdowicz, Krzysztof; Gabanska, Barbara; Krynicka, Ewa; Igielski, Andrzej

    2001-01-01

    The thermal neutron absorption cross section is one of the parameters describing the transport of thermal neutrons in a medium. Theoretical descriptions and experiments which determine the absorption cross section have a wide literature for homogeneous media. The situation comes true e.g. for fluids or amorphous solids. There are many other media which should be treated as heterogeneous. Among others - geological materials. The material heterogeneity for the thermal neutron transport in a considered volume is understood here as an existence of many small regions which differ significantly in their macroscopic neutron diffusion parameters (defined by the absorption and transport cross sections). The final difference, which influences the neutron transport, comes from a combination of the absolute differences between the parameters and of sizes of regions (related to the neutron mean free paths). A rock can be naturally heterogeneous in the above meaning. Besides, it can happen that a preparation of the rock sample for a neutron measurement can increase its natural heterogeneity. (For example, when the rock material is crushed and the measured sample consists of the obtained grains). The question is which granulation is allowed to treat the sample material as still homogeneous, and from which size of the rock grains we have to consider a two-component medium. It has been experimentally proved that the effective absorption of thermal neutrons in a heterogeneous two-component material can significantly differ from the absorption in a homogeneous one which consists of the same elements. The final effect is dependent on a few factors: the macroscopic absorption cross sections of the components, their total mass contributions, and the size of the grains. The ratio of the effective absorption cross section of the heterogeneous material to the cross section of the equivalent homogeneous, is a measure of the heterogeneity effect on the thermal neutron absorption

  4. Neutron activation analysis in geological samples containing rare earths, uranium and thorium

    International Nuclear Information System (INIS)

    Vasconcellos, M.B.A.; Figueiredo, A.M.G.; Berretta, J.R.; Soares, J.C.A.C.R.; Fratin, L.; Goncales, O.L.; Botelho, S.

    1990-01-01

    The neutron activation analysis method was used for determination of rare earths, uranium, thorium and other tracks in geological samples, under the geological standard JB-1 (Geological Survey of Japan) and S-8 and S-13 (IAEA). (L.C.J.A.)

  5. Neutron cross-section determination in geological samples (U)

    International Nuclear Information System (INIS)

    Harris, J.M.; McDaniel, P.J.

    1982-01-01

    The Prompt Gamma Neutron Activation Analysis (PGAA) technique yields elemental composition data which can be used to calculate the macroscopic cross section for any sample. The Small Sample Reactivity Measurements (SSRM) technique yields the macroscopic thermal absorption directly. Experimentally, PGAA is somewhat more difficult because of the calibration and data handling than is SSRM. However, SSRM requires a mathematical model of the reactor which means a rather complicated analysis. Once the model and calibration are completed, data analysis is routine. The SSRM technique is production oriented. 9 figures

  6. Determination of gold and silver in geological standard samples MGI by instrument neutron activation analysis

    International Nuclear Information System (INIS)

    Lu Huijiuan; Zhou; Yunlu

    1987-01-01

    Gold and silver in geological standard samples MGI were determined by instrument neutron activation analysis. The various interferences of nuclides were considered. Corrected factors of the geometry in different positions have been determined. Using the geological standard sample MGM and radiochemical separation neutron activation method as reference, the reliability of this method is proved. Gold content in samples is 0.4-0.009 g/t, silver content is 9-0.3 g/t. Standard deviation is less than 3.5%, the precision of the measurement is 4.8-11.6%

  7. Determination of Iron and Nickel in Geological Samples by Activation Analysis with Reactor Fast Neutrons

    International Nuclear Information System (INIS)

    El Abd, A.

    2009-01-01

    Threshold reactions induced by reactor fast neutrons are well recognized. The concentration of Fe and Ni were determined in nine geological samples by activation analysis with reactor fast neutrons using the threshold reactions 5 4F e( n,p) 54 Mn and 58 Ni ( n, p )'5 8 Co respectively. The fast neutron flux was determined using the reactions 92 Mo(n, 2n) 92 mNb and 95 Mo(n,p) 95 Nb. The determined concentration of Fe and Ni in the samples were checked by determining them in the GSJ JB-1 reference material using the same , ( p, n) reactions. There are a good agreement between the measured and recommended values. The concentrations of Fe were also determined by the ) , ( n, γ) capture reactions in the geological samples and the JB-1 reference material using the K θ - NAA method. There are good agreements between the determined concentrations from the ) , ( p, n) and the ( γ, n) reactions.

  8. Neutron activation analysis of geological samples for gold and accessory elements power reactor

    International Nuclear Information System (INIS)

    Burmistrenko, Yu.N.; Medvedev, A.A.; Kovalenko, V.V.; Markov, A.V.

    1986-01-01

    Possibility of using a power reactor for neutron activation analysis to detect gold and accompanying elements in geological samples of a region was investigated. Specimens (gold-containing samples and standards) were irradiated in a spare channel for ionization chambers located outside the core in graphite reflector. Spectrometry was conducted with the help of a semiconducting detector with LP 4900 multichannel analizer. Sensitivity threshold for gold was (1-3)10 -6 % - (1-2)10 -5 %. It is shown that this method can be used not only for gold detection but for high-sensitive multielement analysis of geological samples

  9. Analysis by neutronic activation of samples of a geologic formation of Cuba

    International Nuclear Information System (INIS)

    Capote Rodriguez, G.; Pena Fortes, B.; Padilla Alvarez, R.; Llanes Castro, A.I.; Perez Zayas, G.; Hernandez Rivero, A.T.; Lopez Reyes, M. C.; Ribeiro Guevara, S.; Molina Insfran, J.

    1997-01-01

    The analysis by neutronic activation (AAN) is an analytical non destructive technique of high accuracy and sensibility. These advantages are very utilized in the determination of geological multielemental samples. In the job 22 elements are determined in 9 geological samples pertaining to the complex of dams of acid composition that includes the graphitic micaceous schist and the quartzites of the Canada Formation, developed fundamentally in the fasteners of the anticlinal Victoria (Yac. of Wolframio Lela, Island of the Youth, Cuba) The results obtained are of great importance for the evaluation of the potentiality of these rocks as fountains or of uranium adjusting and for the geologic prognostic of the region in study. The irradiation of the samples was carried out during three campaigns, in two occasions (October 1992 and November 1994) in the reactor of investigations of the ININ of Mexico, with a flow of thermic neutrons of 10a the 13 n.s -1 cm -2 and in an occasion in the nuclear reactor of the CAB (september 1994), with a flow of thermic neutrons of 6x 10 to the 12 n.s-1. The results were processed with the program ACTAM in the CEADEN. (S. Grainger) [es

  10. The development of neutron activation, sample transportation and γ-ray counting routine system for numbers of geological samples

    International Nuclear Information System (INIS)

    Shibata Shin-nosuke; Tanaka, Tsuyoshi; Minami, Masayo

    2001-01-01

    A new gamma-ray counting and data processing system for non-destructive neutron activation analysis has been set up in Radioisotope Center in Nagoya University. The system carry out gamma-ray counting, sample change and data processing automatically, and is able to keep us away from parts of complicated operations in INAA. In this study, we have arranged simple analytical procedure that makes practical works easier than previous. The concrete flow is described from the reparation of powder rock samples to gamma-ray counting and data processing by the new INAA system. Then it is run over that the analyses used two Geological Survey of Japan rock reference samples JB-1a and JG-1a in order to evaluate how the new analytical procedure give any speediness and accuracy for analyses of geological materials. Two United States Geological Survey reference samples BCR-1 and G-2 used as the standard respectively. Twenty two elements for JB-1a and 25 elements for JG-1a were analyzed, the uncertainty are <5% for Na, Sc, Fe, Co, La, Ce, Sm, Eu, Yb, Lu, Hf, Ta and Th, and of <10% for Cr, Zn, Cs, Ba, Nd, Tb and U. This system will enable us to analyze more than 1500 geologic samples per year. (author)

  11. Neutron activation determination of iridium, gold, platinum, and silver in geologic samples

    International Nuclear Information System (INIS)

    Millard, H.T.

    1986-01-01

    Low-level methods for the determination of iridium and other noble metals have been important in recent years due to interest in locating abundance anomalies associated with the Cretaceous/Tertiary (K/T) boundary. Typical iridium anomalies are in the range of 1 to 100 ppb. Thus methods with detection limits near 0.1 ppb should be adequate to detect K/T boundary anomalies. Radiochemical neutron activation analysis methods continue to be required although instrumental neutron activation analysis techniques employing elaborate gamma-counters are under development. In the procedure employed in this study samples irradiated in the epithermal neutron facility of the U.S. Geological Survey TRIGA Reactor are treated with a mini-fire assay technique. The iridium, gold, and silver are collected in a 1-gram metallic lead button. Primary contaminants at this stage are arsenic and antimony. These can be removed by heating the button with a mixture of sodium peroxide and sodium hydroxide. The resulting 0.2-gram lead bead is counted in a Compton suppression spectrometer. Carrier yields are determined by reirradiation of the lead beads. This procedure has been applied to the U.S.G.S. Standard Rock PCC-1. and samples from K/T boundary sites in the Western Interior of North America. (author)

  12. Neutron activation determination of iridium, gold, platinum, and silver in geologic samples

    International Nuclear Information System (INIS)

    Millard, H.T. Jr.

    1987-01-01

    In the procedure developed in this study, samples irradiated in the epithermal neutron facility of the U.S. Geological Survey TRIGA Reactor (Denver, Colorado) are treated with a mini-free assay technique. The iridium, gold, and silver are collected in a 1-gram metallic lead button. Primary contaminants at this stage are arsenic and antimony. These can be removed by heating the button with a mixture of sodium peroxide and sodium hydroxide. The resulting 0.2-gram lead bead is counted in a Compton suppression spectrometer. Carrier yields are determined by reirradiation of the lead beads. This procedure was applied to the U.S.G.S. Standard Rock PCC-1 and samples from K-T boundary sites in the Western Interior of North America. (author)

  13. Determination of neodymium and gadolinium in geologic samples by neutron activation analysis

    International Nuclear Information System (INIS)

    Souza, M.A. de; Marques, L.S.

    1982-07-01

    The determination of Nd and Gd present in rocks by neutron activation analysis is aimed at. A separation procedure for the rare earth group of elements is presented. The method is based on the retention of 233 Pa, 182 Ta and 46 Sc by hydrated antimony pentoxide (HAP) in a 6M HClO 4 medium. Those radioisotopes are interferences in the gamma-ray spectrum of 153 Gd and 147 Nd. The reliability of the method was tested by means of the geological standards BCR-1 and G-2 from the U.S. Geological Survey. The limitations of the instrumental neutron activation analysis and the advantages of the chemical separation are discussed for the special case of the Nd and Gd determinations. (Author) [pt

  14. Investigation of Six Geological Samples From Wady Sitra Eastern Desert - Egypt Using K0 Neutron Activation Method

    International Nuclear Information System (INIS)

    Soliman, N.F.; Ashmawy, L.S.; Walley El-Dine, N.; Sroor, A.; Mohamed, T.El.

    2010-01-01

    k 0 - Neutron Activation Analysis (k 0 -NAA) is applied to investigate six geological samples collected from Wady Sitra at Eastern desert of Egypt during the survey of gold presence in this area. The samples together with a group of standard (Mo, Fe, Sb and W) are irradiated for 3 hours in one of the inner irradiation site of the Second Egyptian Training and Research Reactor (ETRR-2) operating at power of 19 MW. Mo, Fe and Sb are used to measure the neutron spectrum parameters α(epithermal non-ideality factor) and f (the thermal to epithermal flux ratio) while W is used to test the obtained results. The α( and f parameters are measured using the so-called bare triple monitor method and the obtained results was found to be f = 17.5 ± 0.35 and α(= 0.03±0.002. A Fortran computer program is designed and used to calculate the values of Q 0 (α)for the analyzed elements . The concentration values of 25 elements in the present rock samples have been presented

  15. Iowa Geologic Sampling Points

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Point locations of geologic samples/files in the IGS repository. Types of samples include well cuttings, outcrop samples, cores, drillers logs, measured sections,...

  16. Elemental investigation of (Al-Cu) alloys and some geological samples using neutron activation and XRF analysis techniques

    International Nuclear Information System (INIS)

    Hammad, E.A.M.

    2012-01-01

    Neutron activation analysis (NAA) using k 0 - standardization (k 0 -NAA) is well known method for multi-elemental analysis. The method is used to analyze different samples belonging to different fields. In addition, X- ray fluorescence (XRF) is also used for multi-elemental analysis. XRF complements NAA methods. Both methods were used for investigation of some iron ores and aluminum- cupper alloy (Al-Cu) samples. Elemental concentration of Iron ores and Al-Cu alloy samples were determined by k 0 - NAA and XRF methods. The iron ore samples were collected from Wadi Kareim and Umm Nar sites (the Eastern desert of Egypt). Six and two samples representing the ores of Wadi Kareim and Umm Nar, respectively altogether with the standard samples consisting of Fe, Au , Zr and W and the certified reference sample IAEA Soil-7 were irradiated in one of the irradiated boxes at the Second Egyptian Research Reactor (ETRR- 2). The induced activities were counted using an efficiency calibrated HPGe detector systems. The neutron spectrum parameters α and f characterizing the neutron irradiation position that are needed in applying k 0 -NAA method were determined using the activation product of Zr , Au, Fe and W and found α≅ - 0.048 ±0.002 and f ≅ 38± k 0 -NAA method was applied to determine the elemental concentrations in the two iron ore samples. The concentrations determined were found to vary erratically form one sample to another. The results were discussed and compared with similar results in literature. The accuracy of the k 0 - NAA method was checked by determining the elemental concentration in the IAEA-Soil 7 reference sample. The obtained results are compared with the recommended values. Good agreements were found within 10 %. Short time neutron activation analysis (STNAA) was carried out to determine concentration of major elements in Al-Cu alloy samples. Three (Al-Cu) alloys samples with different concentrations of Cu (2, 3.5 and 5 %) altogether. Au standard sample

  17. k0-NAA implementation and application at IPEN neutron activation laboratory by using the k0-IAEA software: application to geological sample analysis

    International Nuclear Information System (INIS)

    Mariano, Davi Brigatto

    2011-01-01

    The Neutron Activation Analysis Laboratory (LAN-IPEN) has been analysing geological samples such as rocks, soils and sediments, for many years with the INAA comparative method, for geochemical and environmental research. This study presents the results obtained in the implementation of the k 0 -standardization method at LAN - IPEN, for geological sample analysis, by using the program k 0 - IAEA, provided by the International Atomic Energy Agency (IAEA). The thermal to epithermal flux ratio f and the shape factor α of the epithermal flux distribution of the IPEN IEA-R1 nuclear reactor were determined for the pneumatic irradiation facility and one selected irradiation position, for short and long irradiations, respectively. To obtain these factors, the 'are triple-monitor' method with 197 Au- 96 Zr- 94 Zr was used. In order to validate the methodology, the geological reference materials basalts JB-1 (GSJ) and BE-N (IWG-GIT), andesite AGV-1 (USGS), granite GS-N (ANRT), SOIL-7 (IAEA) and sediment Buffalo River Sediment (NIST - BRS-8704), which represent different geological matrices, were analysed. The concentration results obtained agreed with assigned values, with bias less than 10% except for Zn in AGV-1 (11.4%) and Mg in GS-N (13.4%). Three different scores were used to evaluate the results: z-score, zeta-score and Uscore. The z-score showed that the results can be considered satisfactory (z 3) for Mn in BE-N, Mg, Ce and La in GS-N, Mg in JB-1, and Th and Eu in Buffalo River Sediment. The U-score test showed that all results, except Mg in JB-1, were within 95% confidence interval. These results indicate excellent possibilities of using this parametric method at the LAN-IPEN for geological samples analysis in geochemical and environmental studies. (author)

  18. Neutron activation analysis of geological material

    International Nuclear Information System (INIS)

    Greef, G.J.

    1977-05-01

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

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

    International Nuclear Information System (INIS)

    Alian, A.; Sansoni, B.

    1980-04-01

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

  20. Neutron activation analysis of geochemical samples

    International Nuclear Information System (INIS)

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

    1983-06-01

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

  1. Texture analysis with neutron bending on geological/mineralogical multi-phase samples using a locally resolving detector and profile analysis

    International Nuclear Information System (INIS)

    Merz, P.L.

    1991-02-01

    In the context of this work, the NANCY four circuit diffractometer of the University of Bonn at the RRJ2 research reactor at KFA Juelich was equipped with a linear locally resolving scintillation detector JULIOS. To evaluate the diffractogram occurring at a pole figure measurement, user-friendly profile analysis and other evaluation programs were developed on the PC. The course of evaluation was largely automated, so that only a few interactive steps are required. The measuring period of a sample is usually two to three days. Up to 35 pole figures are produced, depending on the phase conditions of the examined sample. The evaluation of up to 900 diffractograms with the aid of the automatically running profile analysis program takes between 30 and 100 minutes on a 20 MHz PC 386. Pole figure datafiles are produced from the intensity data obtained in this way by a conversion program. The texture analyses of copper pyrites ores introduced here are connected with geological questions. (orig.) [de

  2. Improving the effectiveness of geological prospecting with neutron activation analysis

    International Nuclear Information System (INIS)

    Fardy, J.J.

    1984-01-01

    Two examples of the use of neutron activation analysis to improve the effectiveness of geological prospecting are examined. The first is application to the direct hydrogeochemical prospecting for gold in surface waters. The second shows how multielement data banks produced by NAA for a geological formation provide a powerful method for the classification of ore bodies and sedimentary materials

  3. A Geology Sampling System for Small Bodies

    Science.gov (United States)

    Naids, Adam J.; Hood, Anthony D.; Abell, Paul; Graff, Trevor; Buffington, Jesse

    2016-01-01

    Human exploration of microgravity bodies is being investigated as a precursor to a Mars surface mission. Asteroids, comets, dwarf planets, and the moons of Mars all fall into this microgravity category and some are being discussed as potential mission targets. Obtaining geological samples for return to Earth will be a major objective for any mission to a small body. Currently, the knowledge base for geology sampling in microgravity is in its infancy. Humans interacting with non-engineered surfaces in microgravity environment pose unique challenges. In preparation for such missions a team at the NASA Johnson Space Center has been working to gain experience on how to safely obtain numerous sample types in such an environment. This paper describes the type of samples the science community is interested in, highlights notable prototype work, and discusses an integrated geology sampling solution.

  4. A Geology Sampling System for Microgravity Bodies

    Science.gov (United States)

    Hood, Anthony; Naids, Adam

    2016-01-01

    Human exploration of microgravity bodies is being investigated as a precursor to a Mars surface mission. Asteroids, comets, dwarf planets, and the moons of Mars all fall into this microgravity category and some are been discussed as potential mission targets. Obtaining geological samples for return to Earth will be a major objective for any mission to a microgravity body. Currently the knowledge base for geology sampling in microgravity is in its infancy. Humans interacting with non-engineered surfaces in microgravity environment pose unique challenges. In preparation for such missions a team at the NASA Johnson Space Center has been working to gain experience on how to safely obtain numerous sample types in such an environment. This paper describes the type of samples the science community is interested in, highlights notable prototype work, and discusses an integrated geology sampling solution.

  5. Optimal sampling schemes applied in geology

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2010-05-01

    Full Text Available Methodology 6 Results 7 Background and Research Question for Study 2 8 Study Area and Data 9 Methodology 10 Results 11 Conclusions Debba (CSIR) Optimal Sampling Schemes applied in Geology UP 2010 2 / 47 Outline 1 Introduction to hyperspectral remote... sensing 2 Objective of Study 1 3 Study Area 4 Data used 5 Methodology 6 Results 7 Background and Research Question for Study 2 8 Study Area and Data 9 Methodology 10 Results 11 Conclusions Debba (CSIR) Optimal Sampling Schemes applied in Geology...

  6. Neutron activation analysis of minerals from Cuddapah basin geological formations

    International Nuclear Information System (INIS)

    Nagendra Kumar, P.V.; Suresh Kumar, N.; Acharya, R.; Reddy, A.V.R.; Krishna Reddy, L.

    2014-01-01

    Green and yellow serpentines along with two associated minerals namely dolomite and intrusive rock dolerite obtained from the asbestos mines of Cuddapah basin, Andhra Pradesh, India were analyzed by k 0 -based neutron activation analysis (k 0 -NAA) method. Gold ( 197 Au) was used as the single comparator. Two reference materials namely USGS W-1 (geological) and IAEA Soil-7 (environmental) were analyzed as control samples to evaluate the accuracy of the method. A total of 21 elements present at major, minor and trace concentrations were determined in serpentines as well as associated minerals. The elemental concentrations were used for distinguishing and characterizing these minerals, and also to understand the extent of segregation of elements from the associated or host mineral rocks to serpentines. (author)

  7. Assessing rare earth elements in quartz rich geological samples.

    Science.gov (United States)

    Santoro, A; Thoss, V; Ribeiro Guevara, S; Urgast, D; Raab, A; Mastrolitti, S; Feldmann, J

    2016-01-01

    Sodium peroxide (Na2O2) fusion coupled to Inductively Coupled Plasma Tandem Mass Spectrometry (ICP-MS/MS) measurements was used to rapidly screen quartz-rich geological samples for rare earth element (REE) content. The method accuracy was checked with a geological reference material and Instrumental Neutron Activation Analysis (INAA) measurements. The used mass-mode combinations presented accurate results (only exception being (157)Gd in He gas mode) with recovery of the geological reference material QLO-1 between 80% and 98% (lower values for Lu, Nd and Sm) and in general comparable to INAA measurements. Low limits of detection for all elements were achieved, generally below 10 pg g(-1), as well as measurement repeatability below 15%. Overall, the Na2O2/ICP-MS/MS method proved to be a suitable lab-based method to quickly and accurately screen rock samples originating from quartz-rich geological areas for rare earth element content; particularly useful if checking commercial viability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Assessing rare earth elements in quartz rich geological samples

    International Nuclear Information System (INIS)

    Santoro, A.; Thoss, V.; Ribeiro Guevara, S.; Urgast, D.; Raab, A.; Mastrolitti, S.; Feldmann, J.

    2016-01-01

    Sodium peroxide (Na_2O_2) fusion coupled to Inductively Coupled Plasma Tandem Mass Spectrometry (ICP-MS/MS) measurements was used to rapidly screen quartz-rich geological samples for rare earth element (REE) content. The method accuracy was checked with a geological reference material and Instrumental Neutron Activation Analysis (INAA) measurements. The used mass-mode combinations presented accurate results (only exception being "1"5"7Gd in He gas mode) with recovery of the geological reference material QLO-1 between 80% and 98% (lower values for Lu, Nd and Sm) and in general comparable to INAA measurements. Low limits of detection for all elements were achieved, generally below 10 pg g"−"1, as well as measurement repeatability below 15%. Overall, the Na_2O_2/ICP-MS/MS method proved to be a suitable lab-based method to quickly and accurately screen rock samples originating from quartz-rich geological areas for rare earth element content; particularly useful if checking commercial viability. - Highlights: • Na_2O_2 fusion coupled to ICP-MS/MS was used to determine REE in quartz-rich samples. • The method accuracy was checked with a geological reference material and INAA. • Results were within 80–98% recovery of QLO-1 reference material, comparable to INAA. • Detection limits were generally below 10 pg g"−"1, and repeatability was below 15%. • Na_2O_2/ICP-MS/MS proved to be a suitable method for REE in quartz-rich samples.

  9. Activation analysis of gold in geological samples (Paper No. RA-24)

    International Nuclear Information System (INIS)

    Das, N.R.; Bhattacharyya, S.N.

    1990-02-01

    The technique of neutron activation analysis (NAA) has been applied to study the distribution of gold in some geological samples. Traces of gold in the samples were preconcentrated in a solid matrix through a chemical procedure involving solvent extraction using MIBK and coprecipitation with PbS. Gold contents in the samples as determined by NAA vary from ppb to ppm levels. (author)

  10. The monostandard method in thermal neutron activation analysis of geological, biological and environmental materials

    International Nuclear Information System (INIS)

    Alian, A.; Djingova, R.G.; Kroener, B.; Sansoni, B.

    1984-01-01

    A simple method is described for instrumental multielement thermal neutron activation analysis using a monostandard. For geological and air dust samples, iron is used as a comparator, while sodium has advantages for biological materials. To test the capabilities of this method, the values of the effective cross sections of the 23 elements determined were evaluated in a reactor site with an almost pure thermal neutron flux of about 9x10 12 nxcm -2 xs -1 and an epithermal neutron contribution of less than 0.03%. The values obtained were found to agree mostly well with the best literature values of thermal neutron cross sections. The results of an analysis by activation in the same site agree well with the relative method using multielement standards and for several standard reference materials with certified element contents. A comparison of the element contents obtained by the monostandard and relative methods together with corresponding precisions and accuracies is given. (orig.) [de

  11. Index to Marine and Lacustrine Geological Samples (IMLGS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Index to Marine and Lacustrine Geological Samples (IMLGS) describes and provides access to ocean floor and lakebed rock and sediment samples curated by...

  12. Large sample neutron activation analysis of a reference inhomogeneous sample

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  13. Characterization of HPGe gamma spectrometric detectors systems for Instrumental Neutron Activation Analysis (INAA) at the Colombian Geological Survey

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, O., E-mail: osierra@sgc.gov.co; Parrado, G., E-mail: gparrado@sgc.gov.co; Cañón, Y.; Porras, A.; Alonso, D.; Herrera, D. C.; Peña, M., E-mail: mlpena@sgc.gov.co; Orozco, J. [Colombian Geological Survey, Nuclear Affairs Technical Division, Neutron Activation Analysis Laboratory, Bogota D. C. (Colombia)

    2016-07-07

    This paper presents the progress made by the Neutron Activation Analysis (NAA) laboratory at the Colombian Geological Survey (SGC in its Spanish acronym), towards the characterization of its gamma spectrometric systems for Instrumental Neutron Activation Analysis (INAA), with the aim of introducing corrections to the measurements by variations in sample geometry. Characterization includes the empirical determination of the interaction point of gamma radiation inside the Germanium crystal, through the application of a linear model and the use of a fast Monte Carlo N-Particle (MCNP) software to estimate correction factors for differences in counting efficiency that arise from variations in sample density between samples and standards.

  14. Instrumental neutron activation analysis of soil sample

    International Nuclear Information System (INIS)

    Abdul Khalik Haji Wood.

    1983-01-01

    This paper describes the analysis of soil samples collected from 5 different location around Sungai Lui, Kajang, Selangor, Malaysia. These sample were taken at 22-24 cm from the top of the ground and were analysed using the techniques of Instrumental Neutron Activation Analysis (INAA). The analysis on soil sample taken above 22-24 cm level were done in order to determine if there is any variation in elemental contents at different sampling levels. The results indicate a wide variation in the contents of the samples. About 30 elements have been analysed. The major ones are Na, I, Cl, Mg, Al, K, Ti, Ca and Fe. Trace elements analysed were Ba, Sc, V, Cr, Mn, Ga, As, Zn, Br, Rb, Co, Hf, Zr, Th, U, Sb, Cs, Ce, Sm, Eu, Tb, Dy, Yb, Lu and La. (author)

  15. Gamma-ray scanning of neutron activated geological sediments for studying elemental profile distributions

    International Nuclear Information System (INIS)

    Ellinger, M.; Janghorbani, M.; Starke, K.

    1976-01-01

    Gamma-ray scanning for application to elemental profile studies of geological samples was studied with a neutron activated Baltic Shield sediment. Profile distribution of seven elements were measured. The capabilities and limitations of gamma-ray scanning are discussed by comparing the results with profiles obtained after the mechanical subdivision of the sample and the activation of the appropriately sized separates. With respect to the merits and limitations of scanning gamma-ray spectrometry applied to activated complex matrices the following conclusions were drawn. Qualitatively, the scanning method yields the same information as the much more laborious method of mechanical sudbisubdivision. Quantitatively, it is significantly less accurate. The scanning method has the significant advantage of allowing preservation of the sample. This could be important for such speciments as lunar and archeological materials. The method reduces sample preparation time and the possibility of sample contamination. (T.G.)

  16. Astronaut Neil Armstrong studies rock samples during geological field trip

    Science.gov (United States)

    1969-01-01

    Astronaut Neil Armstrong, commander of the Apollo 11 lunar landing mission, studies rock samples during a geological field trip to the Quitman Mountains area near the Fort Quitman ruins in far west Texas.

  17. Reduction of beta-interference in gamma-spectrometric measurements of neutron-irradiated geological material

    International Nuclear Information System (INIS)

    Garmann, L.B.

    1986-01-01

    The analytical technique for INAA, when applied to geological materials, is improved by introducing an electromagnetic field between sample and detector. This field lowers the bremsstrahlung background intensity in the gamma-spectrum by reducing the number of beta-particles reaching the detector. Thus precision, accuracy and lower detection limit are improved. The technique was used on alkalisyenite and on meteoritic material, rocks containing high quantities of sodium and iron, respectively. After neutron irradiation, the induced nuclides sup(24)Na and sup(59)Fe are responsible for high bremsstrahlung interference, which under normal analyitical conditions would mask any x-ray or gamma-ray peaks of interest. The technique is easily applied to multielement analysis of geological and biological materials. It can be combined with sophisticated spectrum-treating techniques such as spectrum stripping and spectrum smoothing, or coincidence-anticoincidence circuits. (author)

  18. Albedo Neutron Dosimetry in a Deep Geological Disposal Repository for High-Level Nuclear Waste.

    Science.gov (United States)

    Pang, Bo; Becker, Frank

    2017-04-28

    Albedo neutron dosemeter is the German official personal neutron dosemeter in mixed radiation fields where neutrons contribute to personal dose. In deep geological repositories for high-level nuclear waste, where neutrons can dominate the radiation field, it is of interest to investigate the performance of albedo neutron dosemeter in such facilities. In this study, the deep geological repository is represented by a shielding cask loaded with spent nuclear fuel placed inside a rock salt emplacement drift. Due to the backscattering of neutrons in the drift, issues concerning calibration of the dosemeter arise. Field-specific calibration of the albedo neutron dosemeter was hence performed with Monte Carlo simulations. In order to assess the applicability of the albedo neutron dosemeter in a deep geological repository over a long time scale, spent nuclear fuel with different ages of 50, 100 and 500 years were investigated. It was found out, that the neutron radiation field in a deep geological repository can be assigned to the application area 'N1' of the albedo neutron dosemeter, which is typical in reactors and accelerators with heavy shielding. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Large Sample Neutron Activation Analysis of Heterogeneous Samples

    International Nuclear Information System (INIS)

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

    2018-01-01

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

  20. Mercury determination in geological samples using radiochemical separation

    International Nuclear Information System (INIS)

    Goncalves, Cristina; Favaro, Deborah I.T.

    1997-01-01

    In this work, a radiochemical procedure is presented to increase the neutron activation analysis sensitivity. After irradiation, geological reference materials - Buffalo River Sediment (BRS- - NIST SRM 2704), Lake Sediment (BCR - CRM 280) and GXR-5 (USGS - AEG) - were leached with aqua regia in a Parr bomb placed in a domestic microwave oven and then bismuth diethyl dithiocarbamate was used to pre concentrate mercury by solvent extraction. This procedure eliminates the interference from 279 keV Se-75 photopeak and background radiation from 511 keV Cu-64 photopeak. (author). 15 refs., 2 figs., 1 tab

  1. Fission-track studies of uranium distribution in geological samples

    International Nuclear Information System (INIS)

    Brynard, H.J.

    1983-01-01

    The standard method of studying uranium distribution in geological material by registration of fission tracks from the thermal neutron-induced fission of 235 U has been adapted for utilisation in the SAFARI-1 reactor at Pelindaba. The theory of fission-track registration as well as practical problems are discussed. The method has been applied to study uranium distribution in a variety of rock types and the results are discussed in this paper. The method is very sensitive and uranium present in quantities far below the detection limit of the microprobe have been detected

  2. Crosscutting Development- EVA Tools and Geology Sample Acquisition

    Science.gov (United States)

    2011-01-01

    Exploration to all destinations has at one time or another involved the acquisition and return of samples and context data. Gathered at the summit of the highest mountain, the floor of the deepest sea, or the ice of a polar surface, samples and their value (both scientific and symbolic) have been a mainstay of Earthly exploration. In manned spaceflight exploration, the gathering of samples and their contextual information has continued. With the extension of collecting activities to spaceflight destinations comes the need for geology tools and equipment uniquely designed for use by suited crew members in radically different environments from conventional field geology. Beginning with the first Apollo Lunar Surface Extravehicular Activity (EVA), EVA Geology Tools were successfully used to enable the exploration and scientific sample gathering objectives of the lunar crew members. These early designs were a step in the evolution of Field Geology equipment, and the evolution continues today. Contemporary efforts seek to build upon and extend the knowledge gained in not only the Apollo program but a wealth of terrestrial field geology methods and hardware that have continued to evolve since the last lunar surface EVA. This paper is presented with intentional focus on documenting the continuing evolution and growing body of knowledge for both engineering and science team members seeking to further the development of EVA Geology. Recent engineering development and field testing efforts of EVA Geology equipment for surface EVA applications are presented, including the 2010 Desert Research and Technology Studies (Desert RATs) field trial. An executive summary of findings will also be presented, detailing efforts recommended for exotic sample acquisition and pre-return curation development regardless of planetary or microgravity destination.

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

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  4. Dynamically Polarized Sample for Neutron Scattering At the Spallation Neutron Source

    International Nuclear Information System (INIS)

    Pierce, Josh; Zhao, J. K.; Crabb, Don

    2009-01-01

    The recently constructed Spallation Neutron Source at the Oak Ridge National Laboratory is quickly becoming the world's leader in neutron scattering sciences. In addition to the world's most intense pulsed neutron source, we are continuously constructing state of the art neutron scattering instruments as well as sample environments to address today and tomorrow's challenges in materials research. The Dynamically Polarized Sample project at the SNS is aimed at taking maximum advantage of polarized neutron scattering from polarized samples, especially biological samples that are abundant in hydrogen. Polarized neutron scattering will allow us drastically increase the signal to noise ratio in experiments such as neutron protein crystallography. The DPS project is near completion and all key components have been tested. Here we report the current status of the project.

  5. Neutron activation analysis of wheat samples

    International Nuclear Information System (INIS)

    Galinha, C.; Anawar, H.M.; Freitas, M.C.; Pacheco, A.M.G.; Almeida-Silva, M.; Coutinho, J.; Macas, B.; Almeida, A.S.

    2011-01-01

    The deficiency of essential micronutrients and excess of toxic metals in cereals, an important food items for human nutrition, can cause public health risk. Therefore, before their consumption and adoption of soil supplementation, concentrations of essential micronutrients and metals in cereals should be monitored. This study collected soil and two varieties of wheat samples-Triticum aestivum L. (Jordao/bread wheat), and Triticum durum L. (Marialva/durum wheat) from Elvas area, Portugal and analyzed concentrations of As, Cr, Co, Fe, K, Na, Rb and Zn using Instrumental Neutron Activation Analysis (INAA) to focus on the risk of adverse public health issues. The low variability and moderate concentrations of metals in soils indicated a lower significant effect of environmental input on metal concentrations in agricultural soils. The Cr and Fe concentrations in soils that ranged from 93-117 and 26,400-31,300 mg/kg, respectively, were relatively high, but Zn concentration was very low (below detection limit Fe>Na>Zn>Cr>Rb>As>Co. Concentrations of As, Co and Cr in root, straw and spike of both varieties were higher than the permissible limits with exception of a few samples. The concentrations of Zn in root, straw and spike were relatively low (4-30 mg/kg) indicating the deficiency of an essential micronutrient Zn in wheat cultivated in Portugal. The elemental transfer from soil to plant decreases with increasing growth of the plant. The concentrations of various metals in different parts of wheat followed the order: Root>Straw>Spike. A few root, straw and spike samples showed enrichment of metals, but the majority of the samples showed no enrichment. Potassium is enriched in all samples of root, straw and spike for both varieties of wheat. Relatively to the seed used for cultivation, Jordao presented higher transfer coefficients than Marialva, in particular for Co, Fe, and Na. The Jordao and Marialva cultivars accumulated not statistically significant different

  6. Neutron activation analysis of wheat samples

    Energy Technology Data Exchange (ETDEWEB)

    Galinha, C. [CERENA-IST, Technical University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Instituto Tecnoclogico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Anawar, H.M. [Instituto Tecnoclogico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Freitas, M.C., E-mail: cfreitas@itn.pt [Instituto Tecnoclogico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Pacheco, A.M.G. [CERENA-IST, Technical University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Almeida-Silva, M. [Instituto Tecnoclogico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Coutinho, J.; Macas, B.; Almeida, A.S. [INRB/INIA-Elvas, National Institute of Biological Resources, Est. Gil Vaz, 7350-228 Elvas (Portugal)

    2011-11-15

    The deficiency of essential micronutrients and excess of toxic metals in cereals, an important food items for human nutrition, can cause public health risk. Therefore, before their consumption and adoption of soil supplementation, concentrations of essential micronutrients and metals in cereals should be monitored. This study collected soil and two varieties of wheat samples-Triticum aestivum L. (Jordao/bread wheat), and Triticum durum L. (Marialva/durum wheat) from Elvas area, Portugal and analyzed concentrations of As, Cr, Co, Fe, K, Na, Rb and Zn using Instrumental Neutron Activation Analysis (INAA) to focus on the risk of adverse public health issues. The low variability and moderate concentrations of metals in soils indicated a lower significant effect of environmental input on metal concentrations in agricultural soils. The Cr and Fe concentrations in soils that ranged from 93-117 and 26,400-31,300 mg/kg, respectively, were relatively high, but Zn concentration was very low (below detection limit <22 mg/kg) indicating that soils should be supplemented with Zn during cultivation. The concentrations of metals in roots and straw of both varieties of wheat decreased in the order of K>Fe>Na>Zn>Cr>Rb>As>Co. Concentrations of As, Co and Cr in root, straw and spike of both varieties were higher than the permissible limits with exception of a few samples. The concentrations of Zn in root, straw and spike were relatively low (4-30 mg/kg) indicating the deficiency of an essential micronutrient Zn in wheat cultivated in Portugal. The elemental transfer from soil to plant decreases with increasing growth of the plant. The concentrations of various metals in different parts of wheat followed the order: Root>Straw>Spike. A few root, straw and spike samples showed enrichment of metals, but the majority of the samples showed no enrichment. Potassium is enriched in all samples of root, straw and spike for both varieties of wheat. Relatively to the seed used for cultivation

  7. A high pressure sample facility for neutron scattering

    International Nuclear Information System (INIS)

    Carlile, C.J.; Glossop, B.H.

    1981-06-01

    Commissioning tests involving deformation studies and tests to destruction as well as neutron diffraction measurements of a standard sample have been carried out on the SERC high pressure sample facility for neutron scattering studies. A detailed description of the pressurising equipment is given. (author)

  8. Determination of average activating thermal neutron flux in bulk samples

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  9. Preserving Geological Samples and Metadata from Polar Regions

    Science.gov (United States)

    Grunow, A.; Sjunneskog, C. M.

    2011-12-01

    The Office of Polar Programs at the National Science Foundation (NSF-OPP) has long recognized the value of preserving earth science collections due to the inherent logistical challenges and financial costs of collecting geological samples from Polar Regions. NSF-OPP established two national facilities to make Antarctic geological samples and drill cores openly and freely available for research. The Antarctic Marine Geology Research Facility (AMGRF) at Florida State University was established in 1963 and archives Antarctic marine sediment cores, dredge samples and smear slides along with ship logs. The United States Polar Rock Repository (USPRR) at Ohio State University was established in 2003 and archives polar rock samples, marine dredges, unconsolidated materials and terrestrial cores, along with associated materials such as field notes, maps, raw analytical data, paleomagnetic cores, thin sections, microfossil mounts, microslides and residues. The existence of the AMGRF and USPRR helps to minimize redundant sample collecting, lessen the environmental impact of doing polar field work, facilitates field logistics planning and complies with the data sharing requirement of the Antarctic Treaty. USPRR acquires collections through donations from institutions and scientists and then makes these samples available as no-cost loans for research, education and museum exhibits. The AMGRF acquires sediment cores from US based and international collaboration drilling projects in Antarctica. Destructive research techniques are allowed on the loaned samples and loan requests are accepted from any accredited scientific institution in the world. Currently, the USPRR has more than 22,000 cataloged rock samples available to scientists from around the world. All cataloged samples are relabeled with a USPRR number, weighed, photographed and measured for magnetic susceptibility. Many aspects of the sample metadata are included in the database, e.g. geographical location, sample

  10. Determination of noble metals in geological materials by radiochemical neutron-activation analysis

    International Nuclear Information System (INIS)

    Ahmad, I.; Ahmad, S.; Morris, D.F.C.

    1977-01-01

    A method for the determination of platinum, palladium, gold and iridium in geological materials following activation with thermal neutrons is described. Radionuclides formed from the elements are separated by a scheme based largely on liquid-liquid extractions. The procedure has been applied to the analysis of US Geological Survey standard rocks and to studies of the distribution of the noble metals in lateritic nickel ores. (author)

  11. Improvement of analytical capabilities of neutron activation analysis laboratory at the Colombian Geological Survey

    Science.gov (United States)

    Parrado, G.; Cañón, Y.; Peña, M.; Sierra, O.; Porras, A.; Alonso, D.; Herrera, D. C.; Orozco, J.

    2016-07-01

    The Neutron Activation Analysis (NAA) laboratory at the Colombian Geological Survey has developed a technique for multi-elemental analysis of soil and plant matrices, based on Instrumental Neutron Activation Analysis (INAA) using the comparator method. In order to evaluate the analytical capabilities of the technique, the laboratory has been participating in inter-comparison tests organized by Wepal (Wageningen Evaluating Programs for Analytical Laboratories). In this work, the experimental procedure and results for the multi-elemental analysis of four soil and four plant samples during participation in the first round on 2015 of Wepal proficiency test are presented. Only elements with radioactive isotopes with medium and long half-lives have been evaluated, 15 elements for soils (As, Ce, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Th, U and Zn) and 7 elements for plants (Br, Co, Cr, Fe, K, Na and Zn). The performance assessment by Wepal based on Z-score distributions showed that most results obtained |Z-scores| ≤ 3.

  12. Improvement of analytical capabilities of neutron activation analysis laboratory at the Colombian Geological Survey

    Energy Technology Data Exchange (ETDEWEB)

    Parrado, G., E-mail: gparrado@sgc.gov.co; Cañón, Y.; Peña, M., E-mail: mlpena@sgc.gov.co; Sierra, O., E-mail: osierra@sgc.gov.co; Porras, A.; Alonso, D.; Herrera, D. C., E-mail: dherrera@sgc.gov.co; Orozco, J. [Colombian Geological Survey, Nuclear Affairs Technical Division, Neutron Activation Analysis Laboratory, Bogota D. C. (Colombia)

    2016-07-07

    The Neutron Activation Analysis (NAA) laboratory at the Colombian Geological Survey has developed a technique for multi-elemental analysis of soil and plant matrices, based on Instrumental Neutron Activation Analysis (INAA) using the comparator method. In order to evaluate the analytical capabilities of the technique, the laboratory has been participating in inter-comparison tests organized by Wepal (Wageningen Evaluating Programs for Analytical Laboratories). In this work, the experimental procedure and results for the multi-elemental analysis of four soil and four plant samples during participation in the first round on 2015 of Wepal proficiency test are presented. Only elements with radioactive isotopes with medium and long half-lives have been evaluated, 15 elements for soils (As, Ce, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Th, U and Zn) and 7 elements for plants (Br, Co, Cr, Fe, K, Na and Zn). The performance assessment by Wepal based on Z-score distributions showed that most results obtained |Z-scores| ≤ 3.

  13. A survey of archaeological and geological samples dated in 1990

    International Nuclear Information System (INIS)

    Mejdahl, V.

    1991-01-01

    A survey of dated archaeological and geological samples is given, using thermoluminescence dating. Some of the sediment samples were also dated by means of optically stimulated luminescence (OSL) using a newly developed infrared diode system. In most cases the luminescence dates are in accordance with archaeological and geological estimates. Some discrepancies were found because some feldspar samples exhibited severe anomalous fading. It may be possible to avoid this problem by basing the dating on OSL of quartz. For sediment samples of Eemian or Early Weichselian age severe underestimates were encountered with both methods. The reason might be related to the large difference between the natural dose rate and that used in laboratory irradiations. Traps corresponding to low-temperature peaks such as the 150 deg. C peak in feldspars will remain almost empty under natural conditions, but will fill up to saturation under laboratory irradiation and thereby more charges will be captured in high-temperature traps. As a result, natural growth curves and laboratory produced luminescence growth curves will have different slopes and this will lead to underestimation. This problem might avoided by holding samples at an elevated temperature during laboratory irradiation, thus keeping the low-temperature traps empty. Preliminary experiments where feldspar samples were held at 130 deg. C during irradiation have given promising results. (AB) (31 refs.)

  14. Introduction of sample environment equipment for neutron scattering experiments

    International Nuclear Information System (INIS)

    Shimojo, Yutaka; Ihata, Yoshiaki; Kaneko, Koji; Takeda, Masayasu

    2013-02-01

    Neutron scattering experiments have been frequently performed under variety of sample conditions, such as various temperatures, pressures, magnetic fields and stresses, and those complex conditions to fully utilize superior properties of neutron. To this aim, a number of sample environment equipment, refrigerators, furnaces, pressure cells, superconducting magnets are equipped in JRR-3 to be used for experiments. In this document, all available sample environment equipment in both JRR-3 reactor and guide halls are summarized. We hope this document would help neutron scattering users to perform effective and excellent experiments. (author)

  15. Determination of uranium and thorium in rock samples from Harargaj Anticline by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Rahman, M.; Molla, N.I.; Sharif, A.K.M.; Basunia, S.; Islam, S.; Miah, R.U.; Hossain, S.M.; Chowdhury, M.I.; Bhuiyan, A.D.; Stegnar, P.

    1993-01-01

    Uranium and thorium were determined in geological materials such as radioactive rock samples collected from the Harargaj Anticline in Moulavi Bazar. The pure instrumental neutron activation analysis (INAA) technique was used in qualitative and quantitative analysis of the rock samples for U and Th. The samples were properly prepared together with their standards and simultaneously irradiated in a neutron flux of the order of 10 12 n*cm -2 *s -1 using the TRIGA MARK II research reactor facility at the AERE, Savar, Dhaka. After activation the samples were subjected to γ-ray spectrometry using a high purity germanium detection system. As a result of the analysis, U and Th could be determined. The data are consistent with the values reported by the ground radiometric survey group for some of the samples. (author) 7 refs.; 1 fig.; 2 tabs

  16. The U.S. Geological Survey Geologic Collections Management System (GCMS)—A master catalog and collections management plan for U.S. Geological Survey geologic samples and sample collections

    Science.gov (United States)

    ,

    2015-01-01

    The U.S. Geological Survey (USGS) is widely recognized in the earth science community as possessing extensive collections of earth materials collected by research personnel over the course of its history. In 2006, a Geologic Collections Inventory was conducted within the USGS Geology Discipline to determine the extent and nature of its sample collections, and in 2008, a working group was convened by the USGS National Geologic and Geophysical Data Preservation Program to examine ways in which these collections could be coordinated, cataloged, and made available to researchers both inside and outside the USGS. The charge to this working group was to evaluate the proposition of creating a Geologic Collections Management System (GCMS), a centralized database that would (1) identify all existing USGS geologic collections, regardless of size, (2) create a virtual link among the collections, and (3) provide a way for scientists and other researchers to obtain access to the samples and data in which they are interested. Additionally, the group was instructed to develop criteria for evaluating current collections and to establish an operating plan and set of standard practices for handling, identifying, and managing future sample collections. Policies and procedures promoted by the GCMS would be based on extant best practices established by the National Science Foundation and the Smithsonian Institution. The resulting report—USGS Circular 1410, “The U.S. Geological Survey Geologic Collections Management System (GCMS): A Master Catalog and Collections Management Plan for U.S. Geological Survey Geologic Samples and Sample Collections”—has been developed for sample repositories to be a guide to establishing common practices in the collection, retention, and disposal of geologic research materials throughout the USGS.

  17. Neutron activation analysis for antimetabolites. [in food samples

    Science.gov (United States)

    1973-01-01

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

  18. The fire assay preconcentration of the platinum group elements for the neutron activation analysis of geological material

    International Nuclear Information System (INIS)

    Parry, S.J.

    1994-01-01

    This paper describes the work that has been carried out using neutron activation analysis (NAA) to develop a rapid and reliable method for the determination of the platinum group elements (PGE: Pt, Pd, Ir, Ru, Rh, and Os) and Au in geological, environmental and industrial samples. The method is based on the now established method of preconcentration with fire assay, followed by NAA of the separated PGE and Au. Recent developments have seen improvements in the technique to eliminate losses due to dissolution procedures, and complete recovery of the elements prior to analysis. The method is now being used to validate inductively coupled plasma-mass spectroscopy methods for analysis of the PGE

  19. Comparison of neutron activation analysis techniques for the determination of uranium concentrations in geological and environmental materials

    International Nuclear Information System (INIS)

    Landsberger, S.; Kapsimalis, R.

    2013-01-01

    We have described the determination of uranium in environmental, geological, and agricultural specimens by three different non-destructive nuclear methods. The effectiveness, as defined as the lower limits of detection in this work, of quantifying trace levels of bulk uranium in geological samples was evaluated for several common NAA techniques. These techniques include short-lived and medium-lived neutron activation analysis using thermal and epithermal neutrons; these results were compared with an assessment of Compton suppressed gamma-ray counting. A careful evaluation of three major (n,γ) reactions with chlorine, manganese and sodium that could impede determining low levels of uranium due to high Compton continuums was done. The evaluation of Compton suppressed passive gamma counting revealed that uranium concentrations below 50 mg kg −1 were not adequate to achieve good counting statistics using the 234m Pa the second daughter product of 238 U. -- Highlights: ► Determination of uranium concentrations in geological, environmental, and agricultural specimens. ► Use of several NAA and passive counting methods. ► Identified several key interferences. ► Use of Compton suppression to minimize effects of interferences

  20. Sample container for neutron activation analysis

    International Nuclear Information System (INIS)

    Lersmacher, B.; Verheijke, M.L.; Jaspers, H.J.

    1983-01-01

    The sample container avoids contaminating the sample substance by diffusion of foreign matter from the wall of the sample container into the sample. It cannot be activated, so that the results of measurements are not falsified by a radioactive container wall. It consists of solid carbon. (orig./HP) [de

  1. Fast neutron (14 MeV) attenuation analysis in saturated core samples and its application in well logging

    International Nuclear Information System (INIS)

    Amin Attarzadeh; Mohammad Kamal Ghassem Al Askari; Tagy Bayat

    2009-01-01

    To introduce the application of nuclear logging, it is appropriate to provide a motivation for the use of nuclear measurement techniques in well logging. Importance aspects of the geological sciences are for instance grain and porosity structure and porosity volume of the rocks, as well as the transport properties of a fluid in the porous media. Nuclear measurements are, as a rule non-intrusive. Namely, a measurement does not destroy the sample, and it does not interfere with the process to be measured. Also, non- intrusive measurements are often much faster than the radiation methods, and can also be applied in field measurements. A common type of nuclear measurement employs neutron irradiation. It is powerful technique for geophysical analysis. In this research we illustrate the detail of this technique and it's applications to well logging and oil industry. Experiments have been performed to investigate the possibilities of using neutron attenuation measurements to determine water and oil content of rock sample. A beam of 14 MeV neutrons produced by a 150 KV neutron generator was attenuated by different samples and subsequently detected with plastic scintillators NE102 (Fast counter). Each sample was saturated with water and oil. The difference in neutron attenuation between dry and wet samples was compared with the fluid content determined by mass balance of the sample. In this experiment we were able to determine 3% of humidity in standard sample model (SiO 2 ) and estimate porosity in geological samples when saturated with different fluids. (Author)

  2. Elemental analysis of brazing alloy samples by neutron activation technique

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  3. Elemental analysis of brazing alloy samples by neutron activation technique

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

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

    International Nuclear Information System (INIS)

    Tzika, F.; Stamatelatos, I.E.

    2004-01-01

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

  5. Measurement of neutron activation in concrete samples

    International Nuclear Information System (INIS)

    Zagar, T.; Ravnik, M.

    2000-01-01

    The results of activation studies of ordinary and barytes concrete samples relevant for research reactor decommissioning are given. Five important long-lived radioactive isotopes ( 54 Mn, 60 Co, 65 Zn, 133 Ba, and 152 Eu) were identified from the gamma-ray spectra measured in the irradiated concrete samples. Activation of these samples was also calculated using ORIGEN2 code. Comparison of calculated and measured results is given. (author)

  6. Study of gamma ray analysis software's. Application to activation analysis of geological samples

    International Nuclear Information System (INIS)

    Silva, Luiz Roberto Nogueira da

    1998-01-01

    A comparative evaluation of the gamma-ray analysis software VISPECT, in relation to two commercial gamma-ray analysis software packages, OMNIGAM (EG and G Ortec) and SAMPO 90 (Canberra) was performed. For this evaluation, artificial gamma ray spectra were created, presenting peaks of different intensities and located at four different regions of the spectrum. Multiplet peaks with equal and different intensities, but with different channel separations, were also created. The results obtained showed a good performance of VISPECT in detecting and analysing single and multiplet peaks of different intensities in the gamma-ray spectrum. Neutron activation analysis of the geological reference material GS-N (IWG-GIT) and of the granite G-94, used in a Proficiency Testing Trial of Analytical Geochemistry Laboratories, was also performed , in order to evaluate the VISEPCT software in the analysis of real samples. The results obtained by using VISPECT were as good or better than the ones obtained using the other programs. (author)

  7. Determination of iridium at low levels (sub ng g-1) in geological materials by neutron activation analysis

    International Nuclear Information System (INIS)

    Morcelli, Claudia Petronilho Ribeiro

    1999-01-01

    The analysis of the platinum group elements (PGE: Ru, Rh, Pd, Os, Ir and Pt) in geological materials is difficult, due to the low concentrations of these elements (ng g -1 or sub ng g -1 ) and their heterogeneous distribution in many geological matrices. The determination of PGE has attracted great interest due not only to the increasing utilization of these elements in modern industry, but also to the information that these elements can provide on mantle processes. The determination of very low amounts of iridium is particularly important on account of some anomalous concentrations of iridium in sedimentary rock samples, related to the impact of an extraterrestrial object responsible for extinctions at the Cretaceous-Tertiary (K-T) boundary. In the present paper, a radiochemical neutron activation method for the determination of iridium in geological materials is presented. The procedure consisted of thermal neutron irradiation of about 500 mg of the sample, followed by sintering with sodium peroxide, precipitation with tellurium and high resolution gamma-ray spectrometry with a hyper-pure Ge detector. The accuracy and precision of the procedure were evaluated by analysis of the certified reference material SARM-7 (South Africa Bureau of Standards) and W-1 (USGS). The detection limit for the analytical conditions employed was 0.004 ng g -1 . The procedure was applied to the reference materials TDB-1 and WGB-1 (CANMET), which present provisional values for Ir, and to the reference materials GXR-3, GXR-5 and GXR- 6 (USGS), which do not present information values for Ir. This work is a contribution to Ir values in these reference materials. As an example of application of the method to real samples, the developed procedure was employed in the determination of iridium in basalts from Parana basin, collected in Bom Guara do Sul, Santa Catarina, provided by the Geosciences Institute of the University of Campinas. (author)

  8. Neutron activation analysis for environmental sample in Thailand

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  9. Automatic sample changer for neutron activation analysis at CDTN, Brazil

    International Nuclear Information System (INIS)

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

    2018-01-01

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

  10. Analysis of atmospheric particulate samples via instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Greenberg, R.R.

    1990-01-01

    Instrumental neutron activation analysis (INAA) is a powerful analytical technique for the elemental characterization of atmospheric particulate samples. It is a true multielement technique with adequate sensitivity to determine 30 to 40 elements in a sample of atmospheric particulate material. Its nondestructive nature allows sample reanalysis by the same or a different analytical technique. In this paper as an example of the applicability of INAA to the study of atmospheric particulate material, a study of the emissions from municipal incinerators is described

  11. The analysis of thallium in geological materials by radiochemical neutron activation and x-ray fluorescence spectrometry: a comparison

    Energy Technology Data Exchange (ETDEWEB)

    McGoldrick, P J; Robinson, P [Tasmania Univ., Sandy Bay, TAS (Australia)

    1994-12-31

    Carrier-based radiochemical neutron activation (RNAA) is a precise and accurate technique for the analysis of Tl in geological materials. For about a decade, until the mid-80s, a procedure modified from Keays et al. (1974) was used at the University of Melbourne to analyse for Tl in a wide variety of geological materials. Samples of powdered rock weighing several hundred milligrams each were irradiated in HIFAR for between 12 hours and 1 week, and subsequently fused with a sodium hydroxide - sodium peroxide mixture and several milligrams of inactive Tl carrier. Following acid digestion of the fusion mixture anion exchange resin was used to separate Tl from the major radioactive rock constituents. The Tl was then stripped from the resin and purified as thallium iodide and a yield measured gravimetrically. Activity from {sup 204}Tl (a {beta}-emitter with a 3 8 year half-life) was measured and Tl determined by reference to pure chemical standards irradiated and processed along with the unkowns. Detection limits for the longer irradiations were about one part per billion. Precision was monitored by repeat analyses of `internal standard` rocks and was estimated to be about five to ten percent (one standard deviation). On the other hand, X-ray fluorescence spectrometry (XRF) was seen as an excellent cost-effective alternative for thallium analysis in geological samples, down to 1 ppm. 6 refs. 1 tab., 1 fig.

  12. The analysis of thallium in geological materials by radiochemical neutron activation and x-ray fluorescence spectrometry: a comparison

    Energy Technology Data Exchange (ETDEWEB)

    McGoldrick, P.J.; Robinson, P. [Tasmania Univ., Sandy Bay, TAS (Australia)

    1993-12-31

    Carrier-based radiochemical neutron activation (RNAA) is a precise and accurate technique for the analysis of Tl in geological materials. For about a decade, until the mid-80s, a procedure modified from Keays et al. (1974) was used at the University of Melbourne to analyse for Tl in a wide variety of geological materials. Samples of powdered rock weighing several hundred milligrams each were irradiated in HIFAR for between 12 hours and 1 week, and subsequently fused with a sodium hydroxide - sodium peroxide mixture and several milligrams of inactive Tl carrier. Following acid digestion of the fusion mixture anion exchange resin was used to separate Tl from the major radioactive rock constituents. The Tl was then stripped from the resin and purified as thallium iodide and a yield measured gravimetrically. Activity from {sup 204}Tl (a {beta}-emitter with a 3 8 year half-life) was measured and Tl determined by reference to pure chemical standards irradiated and processed along with the unkowns. Detection limits for the longer irradiations were about one part per billion. Precision was monitored by repeat analyses of `internal standard` rocks and was estimated to be about five to ten percent (one standard deviation). On the other hand, X-ray fluorescence spectrometry (XRF) was seen as an excellent cost-effective alternative for thallium analysis in geological samples, down to 1 ppm. 6 refs. 1 tab., 1 fig.

  13. Dynamically polarized samples for neutron protein crystallography at the Spallation Neutron Source

    International Nuclear Information System (INIS)

    Zhao, Jinkui; Pierce, Josh; Robertson, J. L.; Herwig, Kenneth W.; Myles, Dean; Cuneo, Matt; Li, Le; Meilleur, Flora; Standaert, Bob

    2016-01-01

    To prepare for the next generation neutron scattering instruments for the planned second target station at the Spallation Neutron Source (SNS) and to broaden the scientific impact of neutron protein crystallography at the Oak Ridge National Laboratory, we have recently ramped up our efforts to develop a dynamically polarized target for neutron protein crystallography at the SNS. Proteins contain a large amount of hydrogen which contributes to incoherent diffraction background and limits the sensitivity of neutron protein crystallography. This incoherent background can be suppressed by using polarized neutron diffraction, which in the same time also improves the coherent diffraction signal. Our plan is to develop a custom Dynamic Nuclear Polarization (DNP) setup tailored to neutron protein diffraction instruments. Protein crystals will be polarized at a magnetic field of 5 T and temperatures of below 1 K. After the dynamic polarization process, the sample will be brought to a frozen-spin mode in a 0.5 T holding field and at temperatures below 100 mK. In a parallel effort, we are also investigating various ways of incorporating polarization agents needed for DNP, such as site specific spin labels, into protein crystals. (paper)

  14. Neutron activation determination of noble metals in samples of terrestrial and cosmic origin using microfire assay concentration

    International Nuclear Information System (INIS)

    Kolesov, G.M.; Sapozhnikov, D.Yu.

    1995-01-01

    The effects of various factors (composition of mixture, relationship between the mass of mixture and sample, value of the Ni:S ratio, fusion time, and temperature) on the conditions of the fire assay concentration of the noble metals with nickel sulfide were investigated, and a method proposed for their quantitative separation from different geological matrices with a neutron activation determination for up to 10 -1 -10 -3 ppb. The proposed method is used to analyse geological samples, i.e. ores, stones, iron meteorites, chromites, soil and lunar rocks. (author)

  15. Phosphorus analysis in milk samples by neutron activation analysis method

    International Nuclear Information System (INIS)

    Oliveira, R.M. de; Cunha, I.I.L.

    1991-01-01

    The determination of phosphorus in milk samples by instrumental thermal neutron activation analysis is described. The procedure involves a short irradiation in a nuclear reactor and measurement of the beta radiation emitted by phosphorus - 32 after a suitable decay period. The sources of error were studied and the established method was applied to standard reference materials of known phosphorus content. (author)

  16. From gold leaf to thermal neutrons: One hundred years of radioactivity and geological exploration (Invited)

    Science.gov (United States)

    Howarth, R. J.

    2010-12-01

    down an oil well to make a down-hole radioactivity profile. Technical advances were rapidly reflected in prospecting on foot, by car, and in the air, with successive adoption of the electrometer (1927); the Geiger-Müller (1945), scintillation (1952) and Hare (1954) counters; and the gamma-spectrometer (1960). The modern era of well-logging began with the patenting by Fearon in 1937 of logs using gamma rays (discovered by Viellard, 1900; named by Rutherford, 1914) and neutrons (discovered by Chadwick, 1932), although the term ‘gamma ray log’ is reported as having first been used on 29 October 1938. A simultaneous gamma and neutron logging device was developed by Sherbatskoy in 1951. Neutron-gamma and gamma-gamma logs followed in the next two years and, by the time it was possible to undertake this with a single instrument (Monaghan 1961), further tools had been developed to attempt detection of both hydrocarbons and salt water in the formations passed through. One-hundred years after Pearce’s discovery, the Thermal Neutron Decay Time Log was introduced; the marriage of radioactivity and geology had truly come of age.

  17. Data reduction for neutron scattering from plutonium samples. Final report

    International Nuclear Information System (INIS)

    Seeger, P.A.

    1997-01-01

    An experiment performed in August, 1993, on the Low-Q Diffractometer (LQD) at the Manual Lujan Jr. Neutron Scattering Center (MLNSC) was designed to study the formation and annealing of He bubbles in aged 239 Pu metal. Significant complications arise in the reduction of the data because of the very high total neutron cross section of 239 Pu, and also because the sample are difficult to make uniform and to characterize. This report gives the details of the data and the data reduction procedures, presents the resulting scattering patterns in terms of macroscopic cross section as a function of momentum transfer, and suggests improvements for future experiments

  18. Thermal neutron absorption cross section of small samples

    International Nuclear Information System (INIS)

    Nghiep, T.D.; Vinh, T.T.; Son, N.N.; Vuong, T.V.; Hung, N.T.

    1989-01-01

    A modified steady method for determining the macroscopic thermal neutron absorption cross section of small samples 500 cm 3 in volume is described. The method uses a moderating block of paraffin, Pu-Be neutron source emitting 1.1x10 6 n.s. -1 , SNM-14 counter and ordinary counting equipment. The interval of cross section from 2.6 to 1.3x10 4 (10 -3 cm 2 g -1 ) was measured. The experimental data are described by calculation formulae. 7 refs.; 4 figs

  19. Rapid uranium analysis by delayed neutron counting of neutron activated samples

    International Nuclear Information System (INIS)

    Papadopoulos, N.N.

    1985-01-01

    The uranium analyzer at the Nuclear Research Center ''Demokritos'' and the delayed neutron method have been used to determine the uranium content in lignite, in chemically enriched samples and in solutions of extractable uranium. The results are compared with data obtained by other methods. In the case of dissolved extractable uranium. The results are in good agreement with X-ray fluorescence data in the range 100 ppm to 2000 ppm while beyond these limits the discrepancies between neutron and spectrophotometric data are observed. The results for lignite samples are in good agreement with gamma spectrometric data. Discrepancies indicate that more extensive intercomparisons are needed to check the reliability of various methods

  20. Neutron activation analysis of core and drill cutting samples from geothermal well drilling

    International Nuclear Information System (INIS)

    Miller, G.E.

    1986-01-01

    Samples of sandstones and shales were analysed by instrumental neutron activation analysis for a total of 30 elements. Three irradiation and five counting periods were employed. Solutions and National Bureau of Standards Reference Materials were used for comparison. The samples were obtained from drill cuttings (with a few core samples) from drillings in the Salton Sea geothermal field of California. These determinations form part of a major study to establish elemental variation as a function of mineral variation as depth and temperature in the well vary. The overall goal is to examine mineral alteration and/or element migration under typical geothermal conditions. The techniques involve typical compromises between maximizing precision for individual element determinations and the amount of time and effort that can be expended, as it is desired to examine large numbers of samples. With the limitations imposed by the reactor flux available at the U.C.Irvine TRIGA reactor, the detectors available, and time factors, most precisions are acceptable for geological comparison purposes. Some additional measurements were made by delayed-neutron counting methods to compare with uranium determinations made by conventional instrumental neutron activation analysis methods. (author)

  1. Determination of gold in geological samples - the present and the future

    International Nuclear Information System (INIS)

    Feriancik, E.

    1997-01-01

    This paper reviews some analytical techniques which have been described for the gold analysis of geological materials: spectrophotometry; flame atomic absorption spectrometry; graphite coupled plasma atomic emission spectrometry; inductively coupled plasma atomic emission spectrometry; inductively coupled plasma-mass spectrometry; neutron activation; electro-analysis methods and fire assay

  2. Separation of interfering elements in the neutron activation analysis of lanthanides in geological materials

    International Nuclear Information System (INIS)

    Saiki, M.

    1988-01-01

    A chemical procedure has been developed for the separation of U, Th, Fe, Sc, Na,Ta, and Mo which interfere in the neutron activation analysis of the lanthanide elements in geological materials. This procedure is based on the solvent extraction of interferents using a solution of tetracycline in benzyl alcohol. The lanthanide elements remaining in the aqueous phase are coprecipitated on calcium oxalate or ferric hydroxide for irradiation and subsequent determination by gamma ray spectrometry. The chemical separation procedure was applied in the analysis of lanthanides in two international geological reference materials GSP-1 (USGS), GS-N (CRPG) and in the analysis of a volcanic rock from Pocos de Caldas, MG, Brazil. The sensitivities for all the lanthanides were determined. (author) [pt

  3. Effects of (α,n) contaminants and sample multiplication on statistical neutron correlation measurements

    International Nuclear Information System (INIS)

    Dowdy, E.J.; Hansen, G.E.; Robba, A.A.; Pratt, J.C.

    1980-01-01

    The complete formalism for the use of statistical neutron fluctuation measurements for the nondestructive assay of fissionable materials has been developed. This formalism includes the effect of detector deadtime, neutron multiplicity, random neutron pulse contributions from (α,n) contaminants in the sample, and the sample multiplication of both fission-related and background neutrons

  4. The correlations between natural elements (K, U, Th) concentrations and thermal neutron absorption cross-section value (Σa) for rock samples of Carpatia area

    International Nuclear Information System (INIS)

    Swakon, J.; Cywicka-Jakiel, T.; Drozdowicz, E.; Gabanska, B.; Loskiewicz, J.; Woznicka, U.

    1991-01-01

    The paper presents a study of correlations between concentrations of potassium, uranium and thorium and thermal neutron absorption cross section in rock samples. This knowledge of correlation should help in recognizing the expansion ways and accumulation places of the elements responsible of high thermal neutron absorption cross section in some geological environments. The correlations show the existence of connections between the thermal neutron absorption cross section value and natural radioactivity elements concentration in rocks. The results confirm the existence of correlations between natural radioactive elements concentrations (particularly thorium) and thermal neutron absorption cross - section value in some rocks. (author). 12 refs, 23 figs, 6 tabs

  5. Neutron spin precession in samples of polarised nuclei and neutron spin phase imaging

    International Nuclear Information System (INIS)

    Piegsa, Florian Michael

    2009-01-01

    The doublet neutron-deuteron (nd) scattering length b 2,d , which is at present only known with an accuracy of 5%, is particularly well suited to fix three-body forces in novel effective field theories at low energies. The understanding of such few-nucleon systems is essential, e.g. for predictions of element abundances in the big-bang and stellar fusion. b 2,d can be obtained via a linear combination of the spin-independent nd scattering length b c,d and the spin-dependent one, b i,d . The aim of this thesis was to perform a high-accuracy measurement of the latter to improve the relative accuracy of b 2,d below 1%. The experiment was performed at the fundamental neutron physics beam line FUNSPIN at the Paul Scherrer Institute in Switzerland. It utilises the effect that the spin of a neutron passing through a target with polarised nuclei performs a pseudomagnetic precession proportional to the spin-dependent scattering length of the nuclei. An ideal method to measure this precession angle very accurately is Ramsey's atomic beam technique, adapted to neutrons. The most crucial part of the experimental setup is the so-called frozen spin target, which consists of a specially designed dilution refrigerator and contains a sample with dynamically polarised nuclear spins. The polarisation of the sample is determined by nuclear magnetic resonance (NMR) techniques. It turned out that the relaxation of the nuclear spins during the necessary ''cross-calibration'' of the two employed NMR systems is ultimately limiting the achievable accuracy of b i,d . During the extensive use of the Ramsey resonance method in the neutron-deuteron experiment, an idea emerged that the applied technique could be exploited in a completely different context, namely polarised neutron radiography. Hence, the second part of the thesis covers the development of a novel neutron radiography technique, based on the spin-dependent interaction of the neutron with ferromagnetic samples and magnetic fields

  6. Neutron spin precession in samples of polarised nuclei and neutron spin phase imaging

    Energy Technology Data Exchange (ETDEWEB)

    Piegsa, Florian Michael

    2009-07-09

    The doublet neutron-deuteron (nd) scattering length b{sub 2,d}, which is at present only known with an accuracy of 5%, is particularly well suited to fix three-body forces in novel effective field theories at low energies. The understanding of such few-nucleon systems is essential, e.g. for predictions of element abundances in the big-bang and stellar fusion. b{sub 2,d} can be obtained via a linear combination of the spin-independent nd scattering length b{sub c,d} and the spin-dependent one, b{sub i,d}. The aim of this thesis was to perform a high-accuracy measurement of the latter to improve the relative accuracy of b{sub 2,d} below 1%. The experiment was performed at the fundamental neutron physics beam line FUNSPIN at the Paul Scherrer Institute in Switzerland. It utilises the effect that the spin of a neutron passing through a target with polarised nuclei performs a pseudomagnetic precession proportional to the spin-dependent scattering length of the nuclei. An ideal method to measure this precession angle very accurately is Ramsey's atomic beam technique, adapted to neutrons. The most crucial part of the experimental setup is the so-called frozen spin target, which consists of a specially designed dilution refrigerator and contains a sample with dynamically polarised nuclear spins. The polarisation of the sample is determined by nuclear magnetic resonance (NMR) techniques. It turned out that the relaxation of the nuclear spins during the necessary ''cross-calibration'' of the two employed NMR systems is ultimately limiting the achievable accuracy of b{sub i,d}. During the extensive use of the Ramsey resonance method in the neutron-deuteron experiment, an idea emerged that the applied technique could be exploited in a completely different context, namely polarised neutron radiography. Hence, the second part of the thesis covers the development of a novel neutron radiography technique, based on the spin-dependent interaction of the

  7. Neutron activation analysis and the geochemistry of common and trace elements at extinction boundaries in the geological record

    International Nuclear Information System (INIS)

    Attrep, M. Jr.; Orth, C.J.; Quintana, L.R.

    1994-01-01

    The discovery of the iridium anomaly at the 65-Ma Cretaceous-Tertiary (K-T) extinction boundary initiated numerous investigations, including the search for the coupling of these extinctions with other astronomical events. One hypothesis is that these periodic extinctions are coupled to terrestrial impacts from cyclic swarms of comets or asteroids. The studies have focused on elucidating the conditions and causes of extinction of life at these geological boundaries using elemental abundance patterns. The authors use instrumental neutron activation methods to determine whole-rock abundances for about 40 trace and common elements in thousands of samples. The platinum group elements (iridium, gold, platinum, and osmium) and nickel are measured by radiochemical activation analysis. The authors can measure iridium at levels down to 1 picogram/gram level

  8. Bedrock Geologic Map of Vermont - Geochronology Sample Locations

    Data.gov (United States)

    Vermont Center for Geographic Information — The bedrock geology was last mapped at a statewide scale 50 years ago at a scale of 1:250,000 (Doll and others, 1961). The 1961 map was compiled from 1:62,500-scale...

  9. Pretreatment procedures applied to samples to be analysed by neutron activation analysis at CDTN/CNEN

    International Nuclear Information System (INIS)

    Francisco, Dovenir; Menezes, Maria Angela de Barros Correia

    2009-01-01

    The neutron activation technique - using several methods - has been applied in 80% of the analytical demand of Division for Reactor and Analytical Techniques at CDTN/CNEN, Belo Horizonte, Minas Gerais. This scenario emphasizes the responsibility of the Laboratory to provide and assure the quality of the measurements. The first step to assure the results quality is the preparation of the samples. Therefore, this paper describes the experimental procedures adopted at CDTN/CNEN in order to uniform conditions of analysis and to avoid contaminations by elements present everywhere. Some of the procedures are based on methods described in the literature; others are based on many years of experience preparing samples from many kinds of matrices. The procedures described are related to geological material - soil, sediment, rock, gems, clay, archaeological ceramics and ore - biological materials - hair, fish, plants, food - water, etc. Analytical results in sediment samples are shown as n example pointing out the efficiency of the experimental procedure. (author)

  10. Neutron emission from impacted solid LiD samples

    International Nuclear Information System (INIS)

    Kaushik, T.C.; Shyam, A.; Kulkarni, L.V.; Srinivasan, M.

    1993-01-01

    Nylon projectiles with 0.1 g to 0.3 g mass, accelerated to velocities of 0.2-1 km/s using a 60 cm long electromagnetic accelerator (railgun), have been impacted upon solid lithium deuteride (LiD) samples of 3 proportional counters. The output from the BF 3 set-up is monitored in several ways to characterize the possible neutron emission from the target. This includes a simple technique of counting the single channel analyser (SCA) output through a dead-time unit to identify bursts of < 100 μs duration. Counting is started after a delay of ∼ 1 ms to avoid the initial interference from the capacitor bank discharge. The signal is also recorded in a storage oscilloscope from the start of projectile acceleration along with a time marker just before the impact. From a number of shots taken with and without the samples, a significant evidence of neutron emission from the LiD samples appears to emerge. The experiments suggest that approximately 100 neutrons might be generated during every such impact in a duration of < 4 ms. (author). 7 refs., 3 figs

  11. Neutron activation analysis of certified samples by the absolute method

    Science.gov (United States)

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

    2015-07-01

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

  12. Fast neutron incineration as an alternative to geologic disposal: the Rubbia proposal

    International Nuclear Information System (INIS)

    Varley, James.

    1997-01-01

    The Energy Amplifier is a ''fast neutron non-critical device'' conceived by Professor Carlo Rubbia and is described as the outcome of a mature cross-fertilisation between modern accelerators and nuclear power. In its currently proposed manifestation it uses thorium and actinite waste as fuel and molten lead for cooling. The lead also acts as a built-in spallation neutron source in the reactor core. Protons from the accelerator are beamed into the spallation region of the core where they produce large numbers of neutrons. These generate heat by nuclear cascades rather than by the self-sustaining chain reaction of a conventional nuclear reactor and the amount of power produced is controlled by the beam current. The basic principle was demonstrated in an experiment at CERN in 1994. The Energy Amplifier has passive safety features, relying only on natural convection for the lead coolant and with cut-off of the proton beam by overflowing lead should the system overheat. A recent discovery has shown that in addition to incinerating transuranic elements and generating a large amount of energy, the system has the potential to transmute long-lived radioactive products from LWRs. This could virtually eliminate the need for geological disposal repositories. The Energy Amplifier would draw on a number of research strands and technologies from around the world. Funding is now being sought to build a 100 MWt prototype. (UK)

  13. Multielemental neutron activation analysis of some egyptian cement samples

    International Nuclear Information System (INIS)

    Eissa, E.A.; Rofail, N.B.; Abdel-Basset, N.; Soroor, A.; Hassan, A.M.

    1996-01-01

    Multielemental analysis of normal, Karnak and sea-water cement samples were performed by neutron activation analysis technique using the (ET-R R-1) reactor for sample irradiation. The Data were collected and analysed by means of the (HPGe) detection system and a Pca computer. A total of 23 elements namely, Na, A1, C 1, K, Ca, Sc, Cr, Mn, Fe, Co, Zn, Sr, Ba, La, Sm, Eu, Yb, Lu, Ta, Au, Th and U were identified and analysed with concentrations ranging from 1 ppm upto 62% a comparison between the elemental concentrations of the three cement types is given. 2 tabs

  14. Multi-element neutron activation analysis of Brazilian coal samples

    International Nuclear Information System (INIS)

    Atalla, L.T.; Requejo, C.S.

    1982-09-01

    The elements U, Th, La, Ce, Nd, Sm, Eu, Dy, Tb, Yb, Lu, Sc, Ta, Hf, Co, Ni, Cr, Mo, Ti, V, W, In, Ga, Mn, Ba, Sr, Mg, Rb, Cs, K, Cl, Br, As, Sb, Au, Ca, Al and Fe were determined in coal samples by instrumental neutron activation analysis, by using both thermal and epithermal neutron irradiations. The irradiation times were 10 minutes and 8 or 16 hours in a position where the thermal neutron flux was about 10 12 n.cm - 2 .s - 1 and 72 non-consecutive hours for epithermal irradiation at a flux of about 10 11 n.Cm - 2 .s - 1 . After the instrumental analysis of the above mentioned elements, Zn and Se were determined with chemical separation. The relative standard deviation of, at least, 4 determinations was about + - 10% for the majority of the results. The coal samples analysed were supplied by: Cia. Estadual da Tecnologia e Saneamento Basico (CETESB-SP), Cia. de Pesquisas e Lavras Minerais (COPELMI-RS), Cia. Carbonifera Urussunga (SC), Cia. Carbonifera Prospera (SC), Cia. Carbonifera Treviso (SC), Cia. Nacional de Mineracao de Carvao do Barro Branco (SC) and Comissao Nacional de Energia Nuclear (CNEN-RJ). (Author) [pt

  15. Nondestructive neutron activation analysis of volcanic samples: Hawaii

    International Nuclear Information System (INIS)

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

    1986-01-01

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  17. Manual for the Portable Handheld Neutron Counter (PHNC) for Neutron Survey and the Measurement of Plutonium Samples

    International Nuclear Information System (INIS)

    Menlove, H.O.

    2005-01-01

    We have designed a portable neutron detector for passive neutron scanning measurement and coincidence counting of bulk samples of plutonium. The counter will be used for neutron survey applications as well as the measurement of plutonium samples for portable applications. The detector uses advanced design 3 He tubes to increase the efficiency and battery operated shift register electronics. This report describes the hardware, performance, and calibration for the system

  18. Isotope identification of Saudi Arabian rock samples from Umm Al-Birak using neutron activation analysis

    International Nuclear Information System (INIS)

    Kahtani, S.A.

    1984-12-01

    Forty eight geological samples from Umm Al-Birak area in the northwest part of Saudi Arabia are analyzed qualitatively and quantitatively using the instrumental neutron activation analysis technique. Samples are properly prepared and irridiated in the reactor facilities of the National Tsing-Hue University in Taiwan. Gamma spectra from high resolution detector are analyzed using BRUTAL code. Final calculations are made by two independent programs, namely, ELCAL and SMPCL. Twenty trace elements are identified and their concentrations are used in the investigation of the geochemistry of the Umm Al-Birak microgranite site. These elements are: Co, Cr, Eu, Fe, Hf, K, La, Lu, Na, Rb, Sc, Sm, Ta, Tb, Th, U, Yb, Zn and Zr. It is shown that high grade area is a differentiated rock that crystallized in a late stage of Umm Al-Birak microgranite area. 43 Ref

  19. Radiochemical neutron activation analysis of gold in geochemical samples

    International Nuclear Information System (INIS)

    Zilliacus, R.

    1983-01-01

    A fast method for the radiochemical neutron activation analysis of gold in geochemical samples is described. The method is intended for samples having background concentrations of gold. The method is based on the dissolution of samples with hydrofluoric acid and aqua regia followed by the dissolution of the fluorides with boric acid and hydrochloric acid. Gold is then adsorbed on activated carbon by filtrating the solution through a thin carbon layer. The activity measurements are carried out using a Ge(Li)-detector and a multichannel analyzer. The chemical yields of the separation determined by reirradiation vary between 60 and 90%. The detection limit of the method is 0.2 ng/g gold in rock samples. USGS standard rocks and exploration reference materials are analyzed and the results are presented and compared with literature data. (author)

  20. Neutron-activation analysis of routine mineral-processing samples

    International Nuclear Information System (INIS)

    Watterson, J.; Eddy, B.; Pearton, D.

    1974-01-01

    Instrumental neutron-activation analysis was applied to a suite of typical mineral-processing samples to establish which elements can be rapidly determined in them by this technique. A total of 35 elements can be determined with precisions (from the counting statistics) ranging from better than 1 per cent to approximately 20 per cent. The elements that can be determined have been tabulated together with the experimental conditions, the precision from the counting statistics, and the estimated number of analyses possible per day. With an automated system, this number can be as high as 150 in the most favourable cases [af

  1. [Recent advances in analysis of petroleum geological samples by comprehensive two-dimensional gas chromatography].

    Science.gov (United States)

    Gao, Xuanbo; Chang, Zhenyang; Dai, Wei; Tong, Ting; Zhang, Wanfeng; He, Sheng; Zhu, Shukui

    2014-10-01

    Abundant geochemical information can be acquired by analyzing the chemical compositions of petroleum geological samples. The information obtained from the analysis provides scientifical evidences for petroleum exploration. However, these samples are complicated and can be easily influenced by physical (e. g. evaporation, emulsification, natural dispersion, dissolution and sorption), chemical (photodegradation) and biological (mainly microbial degradation) weathering processes. Therefore, it is very difficult to analyze the petroleum geological samples and they cannot be effectively separated by traditional gas chromatography/mass spectrometry. A newly developed separation technique, comprehensive two-dimensional gas chromatography (GC x GC), has unique advantages in complex sample analysis, and recently it has been applied to petroleum geological samples. This article mainly reviews the research progres- ses in the last five years, the main problems and the future research about GC x GC applied in the area of petroleum geology.

  2. Semiautomatic exchanger of samples for carry out neutron activation analysis

    International Nuclear Information System (INIS)

    Aguilar H, F.; Quintana C, G.; Torres R, C. E.; Mejia J, J. O.

    2015-09-01

    In this paper the design methodology and implementation of a semiautomatic exchanger of samples for the Analysis Laboratory by Neutron Activation of the Reactor department is presented. Taking into account the antecedents, the necessities of improvement are described, as well as the equipment that previously contained the Laboratory. The project of the semiautomatic exchanger of samples was developed at Instituto Nacional de Investigaciones Nucleares, with its own technology to increase independence from commercial equipment. Each element of the semiautomatic exchanger of samples is described both in the design phase as construction. The achieved results are positive and encouraging for the fulfillment of the proposed objective that is to increase the capacity of the Laboratory. (Author)

  3. Methodological aspects and development of techniques for neutron activation analysis of microcomponents in materials of geologic origin

    International Nuclear Information System (INIS)

    Cohen, I.M.

    1982-01-01

    Some aspects of the activation analysis methodology applied to geological samples activated in nuclear reactors were studied, and techniques were developed for the determination of various elements in different types of matrixes, using gamma spectrometry for the measurement of the products. The consideration of the methodological aspects includes the study of the working conditions, the preparation of samples and standards, irradiations, treatment of the irradiated material, radiochemical separation and measurement. Experiments were carried out on reproducibility and errors in relation to the behaviour of the measurement equipment and that of the methods of area calculation (total area, Covell and Wasson), as well as on the effects of geometry variations on the results of the measurements, the RA-3 reactors's flux variations, and the homogeneity of the samples and standards. Also studied were: the selection of the conditions of determination, including the irradiation and decay times; the irradiation with thermal and epithermal neutrons; the measurement with the use of absorbers, and the resolution of complex peaks. Both non-destructive and radiochemical separation techniques were developed for the analysis of 5 types of geological materials. These methods were applied to the following determinations: a) In, Cd, Mn, Ga and Co in blende; b) La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in fluorites; c) La, Ca, Eu, Tb, Yb, Se and Th in barites and celestites; d) Cu and Zn in soils. The spectral interferences or those due to nuclear reactions were studied and evaluated by mathematical calculation. (M.E.L.) [es

  4. Determination of natural alpha-emitting isotopes of uranium and thorium in environmental and geological samples

    International Nuclear Information System (INIS)

    Crespo, M.T.

    1996-01-01

    It is described the complete radiochemical procedure used for the determination of uranium and thorium isotopes in environmental and geological samples by alpha spectrometry. Source preparation methods, alpha-counting and spectral analysis are also included

  5. Multielement neutron activation analysis of underground water samples

    International Nuclear Information System (INIS)

    Kusaka, Yuzuru; Tsuji, Haruo; Fujimoto, Yuzo; Ishida, Keiko; Mamuro, Tetsuo.

    1980-01-01

    An instrumental neutron activation analysis by gamma-ray spectrometry with high resolution and large volume Ge (Li) detectors followed by data processing with an electronic computer was applied to the multielemental analysis to elucidate the chemical qualities of the underground water which has been widely used in the sake brewing industries in Mikage, Uozaki and Nishinomiya districts, called as miyamizu. The evaporated residues of the water samples were subjected to the neutron irradiations in reactor for 1 min at a thermal flux of 1.5 x 10 12 n.cm -2 .sec -1 and for 30 hrs at a thermal flux of 9.3 x 10 11 n.cm -2 .sec -1 or for 5 hrs at a thermal flux of 3.9 x 10 12 n.cm -2 .sec -1 . Thus, 11 elements in the former short irradiation and 38 elements in the latter two kinds of long irradiation can be analyzed. Conventional chemical analysis including atomic absorption method and others are also applied on the same samples, and putting the all results together, some considerations concerning the geochemical meaning of the analytical values are made. (author)

  6. Geology

    Data.gov (United States)

    Kansas Data Access and Support Center — This database is an Arc/Info implementation of the 1:500,000 scale Geology Map of Kansas, M­23, 1991. This work wasperformed by the Automated Cartography section of...

  7. Improved mesh based photon sampling techniques for neutron activation analysis

    International Nuclear Information System (INIS)

    Relson, E.; Wilson, P. P. H.; Biondo, E. D.

    2013-01-01

    The design of fusion power systems requires analysis of neutron activation of large, complex volumes, and the resulting particles emitted from these volumes. Structured mesh-based discretization of these problems allows for improved modeling in these activation analysis problems. Finer discretization of these problems results in large computational costs, which drives the investigation of more efficient methods. Within an ad hoc subroutine of the Monte Carlo transport code MCNP, we implement sampling of voxels and photon energies for volumetric sources using the alias method. The alias method enables efficient sampling of a discrete probability distribution, and operates in 0(1) time, whereas the simpler direct discrete method requires 0(log(n)) time. By using the alias method, voxel sampling becomes a viable alternative to sampling space with the 0(1) approach of uniformly sampling the problem volume. Additionally, with voxel sampling it is straightforward to introduce biasing of volumetric sources, and we implement this biasing of voxels as an additional variance reduction technique that can be applied. We verify our implementation and compare the alias method, with and without biasing, to direct discrete sampling of voxels, and to uniform sampling. We study the behavior of source biasing in a second set of tests and find trends between improvements and source shape, material, and material density. Overall, however, the magnitude of improvements from source biasing appears to be limited. Future work will benefit from the implementation of efficient voxel sampling - particularly with conformal unstructured meshes where the uniform sampling approach cannot be applied. (authors)

  8. Optimal sampling schemes for vegetation and geological field visits

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2012-07-01

    Full Text Available The presentation made to Wits Statistics Department was on common classification methods used in the field of remote sensing, and the use of remote sensing to design optimal sampling schemes for field visits with applications in vegetation...

  9. Determination of Rare Earth Elements in Geological Samples Using Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Bhatt, Chet R; Jain, Jinesh C; Goueguel, Christian L; McIntyre, Dustin L; Singh, Jagdish P

    2018-01-01

    Laser-induced breakdown spectroscopy (LIBS) was used to detect rare earth elements (REEs) in natural geological samples. Low and high intensity emission lines of Ce, La, Nd, Y, Pr, Sm, Eu, Gd, and Dy were identified in the spectra recorded from the samples to claim the presence of these REEs. Multivariate analysis was executed by developing partial least squares regression (PLS-R) models for the quantification of Ce, La, and Nd. Analysis of unknown samples indicated that the prediction results of these samples were found comparable to those obtained by inductively coupled plasma mass spectrometry analysis. Data support that LIBS has potential to quantify REEs in geological minerals/ores.

  10. Neutron-Irradiated Samples as Test Materials for MPEX

    International Nuclear Information System (INIS)

    Ellis, Ronald James; Rapp, Juergen

    2015-01-01

    Plasma Material Interaction (PMI) is a major concern in fusion reactor design and analysis. The Material-Plasma Exposure eXperiment (MPEX) will explore PMI under fusion reactor plasma conditions. Samples with accumulated displacements per atom (DPA) damage produced by fast neutron irradiations in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) will be studied in the MPEX facility. This paper presents assessments of the calculated induced radioactivity and resulting radiation dose rates of a variety of potential fusion reactor plasma-facing materials (such as tungsten). The scientific code packages MCNP and SCALE were used to simulate irradiation of the samples in HFIR including the generation and depletion of nuclides in the material and the subsequent composition, activity levels, gamma radiation fields, and resultant dose rates as a function of cooling time. A challenge of the MPEX project is to minimize the radioactive inventory in the preparation of the samples and the sample dose rates for inclusion in the MPEX facility

  11. Radiocarbon dating of archaeological geological and groundwater samples

    International Nuclear Information System (INIS)

    Chinh, N.K.; Dung, H.H.; Quan, H.M.; Thuy, T.K.

    1989-01-01

    In the context of the project VIE/8/003 sponsored by the IAEA, a regular and complete C 1 4 laboratory was installed at the Centre of the Nuclear Techniques in 1986. In this paper the authors present the procedure of sample treatment and saple activity measurement of the radiocarbon method and some preliminary results obtained after more than one year of operation of the laboratory

  12. CdTe detector based PIXE mapping of geological samples

    Energy Technology Data Exchange (ETDEWEB)

    Chaves, P.C., E-mail: cchaves@ctn.ist.utl.pt [Centro de Física Atómica da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, Campus Tecnológico e Nuclear, EN10, 2686-953 Sacavém (Portugal); Taborda, A. [Centro de Física Atómica da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, Campus Tecnológico e Nuclear, EN10, 2686-953 Sacavém (Portugal); Oliveira, D.P.S. de [Laboratório Nacional de Energia e Geologia (LNEG), Apartado 7586, 2611-901 Alfragide (Portugal); Reis, M.A. [Centro de Física Atómica da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, Campus Tecnológico e Nuclear, EN10, 2686-953 Sacavém (Portugal)

    2014-01-01

    A sample collected from a borehole drilled approximately 10 km ESE of Bragança, Trás-os-Montes, was analysed by standard and high energy PIXE at both CTN (previous ITN) PIXE setups. The sample is a fine-grained metapyroxenite grading to coarse-grained in the base with disseminated sulphides and fine veinlets of pyrrhotite and pyrite. Matrix composition was obtained at the standard PIXE setup using a 1.25 MeV H{sup +} beam at three different spots. Medium and high Z elemental concentrations were then determined using the DT2fit and DT2simul codes (Reis et al., 2008, 2013 [1,2]), on the spectra obtained in the High Resolution and High Energy (HRHE)-PIXE setup (Chaves et al., 2013 [3]) by irradiation of the sample with a 3.8 MeV proton beam provided by the CTN 3 MV Tandetron accelerator. In this paper we present results, discuss detection limits of the method and the added value of the use of the CdTe detector in this context.

  13. High-resolution neutron spectroscopy on protein solution samples

    International Nuclear Information System (INIS)

    Grimaldo, M.; Henning, M.; Roosen-Runge, F.; Seydel, T.; Jalarvo, N.; Zamponi, M.; Zanini, F.; Zhang, F.; Schreiber, F.

    2015-01-01

    Proteins in solution are subject to a complex superposition of global translational and rotational diffusion as well as internal relaxations covering a wide range of time scales. With the advent of new high-flux neutron spectrometers in combination with enhanced analysis frameworks it has become possible to separate these different contributions. We discuss new approaches to the analysis by presenting example spectra and fits from data recorded on the backscattering spectrometers IN16, IN16B, and BASIS on the same protein solution sample. We illustrate the separation of the rotational and translational diffusion contribution, the accurate treatment of the solvent contribution, and the extraction of information on internal fluctuations. We also highlight the progress made in passing from second- to third-generation backscattering spectrometers. (authors)

  14. The effect of albedo neutrons on the neutron multiplication of small plutonium oxide samples in a PNCC chamber

    CERN Document Server

    Bourva, L C A; Weaver, D R

    2002-01-01

    This paper describes how to evaluate the effect of neutrons reflected from parts of a passive neutron coincidence chamber on the neutron leakage self-multiplication, M sub L , of a fissile sample. It is shown that albedo neutrons contribute, in the case of small plutonium bearing samples, to a significant part of M sub L , and that their effect has to be taken into account in the relationship between the measured coincidence count rates and the sup 2 sup 4 sup 0 Pu effective mass of the sample. A simple one-interaction model has been used to write the balance of neutron gains and losses in the material when exposed to the re-entrant neutron flux. The energy and intensity profiles of the re-entrant flux have been parameterised using Monte Carlo MCNP sup T sup M calculations. This technique has been implemented for the On Site Laboratory neutron/gamma counter within the existing MEPL 1.0 code for the determination of the neutron leakage self-multiplication. Benchmark tests of the resulting MEPL 2.0 code with MC...

  15. Progress on using deuteron-deuteron fusion generated neutrons for 40Ar/39Ar sample irradiation

    Science.gov (United States)

    Rutte, Daniel; Renne, Paul R.; Becker, Tim; Waltz, Cory; Ayllon Unzueta, Mauricio; Zimmerman, Susan; Hidy, Alan; Finkel, Robert; Bauer, Joseph D.; Bernstein, Lee; van Bibber, Karl

    2017-04-01

    technical improvements are necessary to increase the neutron flux to make geologic sample irradiation possible in a reasonable experimental timeframe. (This work was performed under the auspices of the U.S. Department of Energy (DOE) by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344, and by the DOE Office of Science, Office of Nuclear Physics under Contract No. DE-AC02- 05CH11231 (LBNL).)

  16. Reliability of the k{sub 0}-standardization method using geological sample analysed in a proficiency test

    Energy Technology Data Exchange (ETDEWEB)

    Pelaes, Ana Clara O.; Menezes, Maria Ângela de B.C., E-mail: anacpelaes@gmail.com, E-mail: menezes@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-11-01

    The Neutron Activation Analysis (NAA) is an analytical technique to determine the elemental chemical composition in samples of several matrices, that has been applied by the Laboratory for Neutron Activation Analysis, located at Centro de Desenvolvimento da Tecnologia Nuclear /Comissão Nacional de Energia Nuclear (Nuclear Technology Development Center/Brazilian Commission for Nuclear Energy), CDTN/CNEN, since the starting up of the TRIGA MARK I IPR-R1 reactor, in 1960. Among the methods of application of the technique, the k{sub 0}-standardization method, which was established at CDTN in 1995, is the most efficient and in 2003 it was reestablished and optimized. In order to verify the reproducibility of the results generated by the application of the k{sub 0}-standardization method at CDTN, aliquots of a geological sample sent by WEPAL (Wageningen Evaluating Programs for Analytical Laboratories) were analysed and its results were compared with the results obtained through the Intercomparison of Results organized by the International Atomic Energy Agency in 2015. WEPAL is an accredited institution for the organisation of interlaboratory studies, preparing and organizing proficiency testing schemes all over the world. Therefore, the comparison with the results provided aims to contribute to the continuous improvement of the quality of the results obtained by the CDTN. The objective of this study was to verify the reliability of the method applied two years after the intercomparison round. (author)

  17. ICP-MS applications for the analysis of geological materials and environmental samples

    International Nuclear Information System (INIS)

    Bendl, J.

    1997-01-01

    This work deals with applications of inductively coupled plasma - mass spectrometry applications for the analysis of geological materials and environmental samples. There are instrumentation, calibration, alternatives of sample introduction, interferences, trace elements analysis, rare earth elements and uranium and thorium, precious metals, isotopic analysis and environmental analysis discussed

  18. Fast neutron incineration in the energy amplifier as alternative to geologic storage the case of Spain

    CERN Document Server

    Rubbia, Carlo; Kadi, Y; Rubio, Juan Antonio

    1997-01-01

    In previous reports [1][2] we have presented the conceptual design of a fast neutron driven sub-critical device (Energy Amplifier) designed both for energy amplification (production) and for the incineration of unwanted ³waste² from Nuclear Light Water Reactors (LWR). The latter scheme is here applied to the specific case of Spain, where 9 large LWR¹s are presently in operation. It is shown that a cluster of 5 EA¹s is a very effective and realistic solution to the elimination (in 37 years) of the present and foreseen (till 2029) LWR-Waste stockpiles of Spain, but with major improvements over Geologic Storage, since: (1) only a Low Level Waste (LLW) surface repository of reasonable size is ultimately required; (2) the large amount of energy stored in the trans-Uranics is recovered, amounting for each of the 37 years of incineration to a saving of about 8% of the present primary energy demand of Spain (100 MTep/y); (3) the slightly enriched (1.1%) Uranium, unburned by LWR¹s, can be recovered for further us...

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  20. Neutron moderation in a bulk sample and its effects on PGNAA setup geometry

    International Nuclear Information System (INIS)

    Al-Jarallah, M.I.; Naqvi, A.A.; Fazal-ur-Rehman,; Maselehuddin, M.; Abu-Jarad, F.; Raashid, M.

    2003-01-01

    In a prompt gamma ray neutron activation analysis (PGNAA) setup, the neutron moderation in the bulk sample also plays a key role. This can even dominate the thermalization effects of the external moderator in some cases. In order to study the neutron moderation effect in the bulk sample, moderators with two different sizes of the sample were tested at the King Fahd University of Petroleum and Minerals (KFUPM) PGNAA facility. In these tests, the thermal neutron relative intensity and prompt gamma ray yield from the two moderators were measured using nuclear track detectors (NTDs) and NaI detector, respectively. As predicted by Monte Carlo simulations, the measured intensity of thermal neutron inside the large sample cavity due to the external moderator was smaller than that from the smaller sample cavity. Due to its larger size, additional thermalization of neutrons will take place in the larger sample. In spite of smaller thermal neutron yield from the external moderator at the large sample location, higher yield of the prompt gamma ray was observed as compared to that from the smaller sample. This confirms the significance of neutron moderation effects in the bulk sample and can thereby affect the PGNAA geometry size. This allows larger samples in conjunction with smaller moderators in the PGNAA setup

  1. Neutron moderation in a bulk sample and its effects on PGNAA setup geometry

    Energy Technology Data Exchange (ETDEWEB)

    Al-Jarallah, M.I. E-mail: mibrahim@kfupm.edu.sa; Naqvi, A.A.; Fazal-ur-Rehman,; Maselehuddin, M.; Abu-Jarad, F.; Raashid, M

    2003-06-01

    In a prompt gamma ray neutron activation analysis (PGNAA) setup, the neutron moderation in the bulk sample also plays a key role. This can even dominate the thermalization effects of the external moderator in some cases. In order to study the neutron moderation effect in the bulk sample, moderators with two different sizes of the sample were tested at the King Fahd University of Petroleum and Minerals (KFUPM) PGNAA facility. In these tests, the thermal neutron relative intensity and prompt gamma ray yield from the two moderators were measured using nuclear track detectors (NTDs) and NaI detector, respectively. As predicted by Monte Carlo simulations, the measured intensity of thermal neutron inside the large sample cavity due to the external moderator was smaller than that from the smaller sample cavity. Due to its larger size, additional thermalization of neutrons will take place in the larger sample. In spite of smaller thermal neutron yield from the external moderator at the large sample location, higher yield of the prompt gamma ray was observed as compared to that from the smaller sample. This confirms the significance of neutron moderation effects in the bulk sample and can thereby affect the PGNAA geometry size. This allows larger samples in conjunction with smaller moderators in the PGNAA setup.

  2. A rapid method for the determination on fluoride in geological samples

    International Nuclear Information System (INIS)

    Josephson, M.; Cook, E.B.T.; Dixon, K.

    1977-01-01

    An account is given of a rapid procedure for the determination by use of the specific-ion electrode of fluoride in geological samples. The sample is fused with sodium hydroxide in a nickel crucible in a muffle furnace. The melt is leached with water, a buffer solution of ammonium citrate is added, and the fluoride activity is measured with a specific-ion electrode. All operations are carried out in the crucible, making possible approximately 100 determinations a day. The precision of the method is approximately 10 per cent at a fluoride concentration of 500 p.p.m., which is acceptable for geological-survey work [af

  3. Experiences in the ICP-MS analysis of geological and environmental samples

    International Nuclear Information System (INIS)

    Kallio, E.

    1994-01-01

    Inductively coupled plasma mass spectrometry (ICP-MS) has been used at the Geological Survey of Finland since 1991. Applied to determination of trace and ultra trace elements in water, sediments, biological samples and rocks. The strength of the technique lies in the ability to determine isotope ratios, and elements that are difficult or expensive to determine by other techniques, e.g. platinum group elements (PGEs), rare earths elements (REEs) and toxic metals (As, Be, Cd, Hg, Pb, Tl, U). An important part of the analysis is the pretreatment of the samples before the measurement. This paper gives an overview of the methods used at the Geological Survey. (orig.). (5 refs.)

  4. Investigating the Geological History of Asteroid 101955 Bennu Through Remote Sensing and Returned Sample Analyses

    Science.gov (United States)

    Messenger, S.; Connolly, H. C., Jr.; Lauretta, D. S.; Bottke, W. F.

    2014-01-01

    The NASA New Frontiers Mission OSRIS-REx will return surface regolith samples from near-Earth asteroid 101955 Bennu in September 2023. This target is classified as a B-type asteroid and is spectrally similar to CI and CM chondrite meteorites [1]. The returned samples are thus expected to contain primitive ancient Solar System materials that formed in planetary, nebular, interstellar, and circumstellar environments. Laboratory studies of primitive astromaterials have yielded detailed constraints on the origins, properties, and evolutionary histories of a wide range of Solar System bodies. Yet, the parent bodies of meteorites and cosmic dust are generally unknown, genetic and evolutionary relationships among asteroids and comets are unsettled, and links between laboratory and remote observations remain tenuous. The OSIRIS-REx mission will offer the opportunity to coordinate detailed laboratory analyses of asteroidal materials with known and well characterized geological context from which the samples originated. A primary goal of the OSIRIS-REx mission will be to provide detailed constraints on the origin and geological and dynamical history of Bennu through coordinated analytical studies of the returned samples. These microanalytical studies will be placed in geological context through an extensive orbital remote sensing campaign that will characterize the global geological features and chemical diversity of Bennu. The first views of the asteroid surface and of the returned samples will undoubtedly bring remarkable surprises. However, a wealth of laboratory studies of meteorites and spacecraft encounters with primitive bodies provides a useful framework to formulate priority scientific questions and effective analytical approaches well before the samples are returned. Here we summarize our approach to unraveling the geological history of Bennu through returned sample analyses.

  5. Improved Geologic Interpretation of Non-invasive Electrical Resistivity Imaging from In-situ Samples

    Science.gov (United States)

    Mucelli, A.; Aborn, L.; Jacob, R.; Malusis, M.; Evans, J.

    2016-12-01

    Non-invasive geophysical techniques are useful in characterizing the subsurface geology without disturbing the environment, however, the ability to interpret the subsurface is enhanced by invasive work. Since geologic materials have electrical resistivity values it allows for a geologic interpretation to be made based on variations of electrical resistivity measured by electrical resistivity imaging (ERI). This study focuses on the pre-characterization of the geologic subsurface from ERI collected adjacent to the Montandon Marsh, a wetland located near Lewisburg, PA within the West Branch of the Susquehanna River watershed. The previous invasive data, boreholes, indicate that the subsurface consists of limestone and shale bedrock overlain with sand and gravel deposits from glacial outwash and aeolian processes. The objective is to improve our understanding of the subsurface at this long-term hydrologic research site by using excavation results, specifically observed variations in geologic materials and electrical resistivity laboratory testing of subsurface samples. The pre-excavation ERI indicated that the shallow-most geologic material had a resistivity value of 100-500 ohm-m. In comparison, the laboratory testing indicated the shallow-most material had the same range of electrical resistivity values depending on saturation levels. The ERI also showed that there was an electrically conductive material, 7 to 70 ohm-m, that was interpreted to be clay and agreed with borehole data, however, the excavation revealed that at this depth range the geologic material varied from stratified clay to clay with cobbles to weathered residual clay. Excavation revealed that the subtle variations in the electrical conductive material corresponded well with the variations in the geologic material. We will use these results to reinterpret previously collected ERI data from the entire long-term research site.

  6. Transmission of 14 MeV neutrons through concrete, soil, sugar, wood and coal samples - a Monte Carlo Study

    International Nuclear Information System (INIS)

    Abdelmonem, M.S.; Naqvi, A.A.

    2006-01-01

    Full text: Fast neutrons transmission measurements are ideal for the elemental analysis of bulk samples. In particular, they can be used to determine the hydrogen concentration in bulk samples. In the present study, Monte Carlo simulations have been carried to calculate the intensity of 14 MeV neutrons transmitted through concrete, soil, sugar, wood and coal samples. The simulated set-up consists of a cylindrical sample, placed at a distance of 9 cm from the neutron source. Fast neutrons transmitted through the sample are collimated through a double truncated neutron collimator to a fast neutron detector. The collimator contains a mixture of paraffin and lithium carbonate. In this study, transmitted intensity of fast neutron through each sample was calculated as a function of moisture contents of the sample for 14 MeV neutrons. The moisture contents of the samples were varied over 0-7 wt. %. The calculated intensity of 14 MeV neutrons transmitted through the samples, shows effects related to fast neutron thermalization in hydrogen of moisture and energy dependence of neutron transmission through the sample materials. This is clearly shown by different gradients of neutron yield vs moisture content curves of these samples. The gradient of the neutron yield curves for the 14 MeV neutrons has a lower value than those reported for a 241 Am-Be neutron source

  7. Sample to moderator volume ratio effects in neutron yield from a PGNAA setup

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, A.A. [Department of Physics, King Fahd University of Petroleum and Minerals, KFUPM Box 1815, Dhahran-31261 (Saudi Arabia)]. E-mail: aanaqvi@kfupm.edu.sa; Fazal-ur-Rehman [Department of Physics, King Fahd University of Petroleum and Minerals, KFUPM Box 1815, Dhahran-31261 (Saudi Arabia); Nagadi, M.M. [Department of Physics, King Fahd University of Petroleum and Minerals, KFUPM Box 1815, Dhahran-31261 (Saudi Arabia); Khateeb-ur-Rehman [Department of Physics, King Fahd University of Petroleum and Minerals, KFUPM Box 1815, Dhahran-31261 (Saudi Arabia)

    2007-02-15

    Performance of a prompt gamma ray neutron activation analysis (PGNAA) setup depends upon thermal neutron yield at the PGNAA sample location. For a moderator, which encloses a sample, thermal neutron intensity depends upon the effective moderator volume excluding the void volume due to sample volume. A rectangular moderator assembly has been designed for the King Fahd University of Petroleum and Minerals (KFUPM) PGNAA setup. The thermal and fast neutron yield has been measured inside the sample cavity as a function of its front moderator thickness using alpha particle tracks density and recoil proton track density inside the CR-39 nuclear track detectors (NTDs). The thermal/fast neutron yield ratio, obtained from the alpha particle tracks density to proton tracks density ratio in the NTDs, shows an inverse correlation with sample to moderator volume ratio. Comparison of the present results with the previously published results of smaller moderators of the KFUPM PGNAA setup confirms the observation.

  8. Sorption of radionuclides on geological samples from the Bradwell, Elstow, Fulbeck and Killingholme site investigations

    International Nuclear Information System (INIS)

    Berry, J.A.; Coates, H.A.; Green, A.; Littleboy, A.K.

    1988-06-01

    The sorption of chloride, caesium, calcium, nickel and americium on geological samples collected during the site investigations at Bradwell, Elstow, Fulbeck and Killingholme has been studied. Through-diffusion and batch sorption techniques were used and experiments were designed to give a direct comparison between the sorptive behaviour of material from each site. (author)

  9. Multielemental analysis of Korean geological reference samples by INAA, ICP-AES and ICP-MS

    International Nuclear Information System (INIS)

    Naoki Shirai; Hiroki Takahashi; Yuta Yokozuka; Mitsuru Ebihara; Meiramkhan Toktaganov; Shun Sekimoto

    2015-01-01

    Six Korean geological reference samples (KB-1, KGB-1, KT-1, KD-1, KG-1 and KG-2) prepared by Korea Institutes of Geoscience and Mineral Resources were analyzed by using INAA, ICP-AES and ICP-MS. Some elements could be determined by both INAA and non-INAA methods (ICP-AES and ICP-MS), and these data are consistent with each other. This study confirms that a combination of ICP-AES and ICP-MS is comparable to INAA in determining a wide range of major, minor and trace elements in geological materials. (author)

  10. Manual for the Epithermal Neutron Multiplicity Detector (ENMC) for Measurement of Impure MOX and Plutonium Samples

    International Nuclear Information System (INIS)

    Menlove, H. O.; Rael, C. D.; Kroncke, K. E.; DeAguero, K. J.

    2004-01-01

    We have designed a high-efficiency neutron detector for passive neutron coincidence and multiplicity counting of dirty scrap and bulk samples of plutonium. The counter will be used for the measurement of impure plutonium samples at the JNC MOX fabrication facility in Japan. The counter can also be used to create working standards from bulk process MOX. The detector uses advanced design "3He tubes to increase the efficiency and to shorten the neutron die-away time. The efficiency is 64% and the die-away time is 19.1 ?s. The Epithermal Neutron Multiplicity Counter (ENMC) is designed for high-precision measurements of bulk plutonium samples with diameters of less than 200 mm. The average neutron energy from the sample can be measured using the ratio of the inner ring of He-3 tubes to the outer ring. This report describes the hardware, performance, and calibration for the ENMC.

  11. X-ray spectrometry and X-ray microtomography techniques for soil and geological samples analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kubala-Kukuś, A.; Banaś, D.; Braziewicz, J. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Dziadowicz, M.; Kopeć, E. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Majewska, U. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Mazurek, M.; Pajek, M.; Sobisz, M.; Stabrawa, I. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Wudarczyk-Moćko, J. [Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Góźdź, S. [Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Institute of Public Health, Jan Kochanowski University, IX Wieków Kielc 19, 25-317 Kielce (Poland)

    2015-12-01

    A particular subject of X-ray fluorescence analysis is its application in studies of the multielemental sample of composition in a wide range of concentrations, samples with different matrices, also inhomogeneous ones and those characterized with different grain size. Typical examples of these kinds of samples are soil or geological samples for which XRF elemental analysis may be difficult due to XRF disturbing effects. In this paper the WDXRF technique was applied in elemental analysis concerning different soil and geological samples (therapeutic mud, floral soil, brown soil, sandy soil, calcium aluminum cement). The sample morphology was analyzed using X-ray microtomography technique. The paper discusses the differences between the composition of samples, the influence of procedures with respect to the preparation of samples as regards their morphology and, finally, a quantitative analysis. The results of the studies were statistically tested (one-way ANOVA and correlation coefficients). For lead concentration determination in samples of sandy soil and cement-like matrix, the WDXRF spectrometer calibration was performed. The elemental analysis of the samples was complemented with knowledge of chemical composition obtained by X-ray powder diffraction.

  12. X-ray spectrometry and X-ray microtomography techniques for soil and geological samples analysis

    International Nuclear Information System (INIS)

    Kubala-Kukuś, A.; Banaś, D.; Braziewicz, J.; Dziadowicz, M.; Kopeć, E.; Majewska, U.; Mazurek, M.; Pajek, M.; Sobisz, M.; Stabrawa, I.; Wudarczyk-Moćko, J.; Góźdź, S.

    2015-01-01

    A particular subject of X-ray fluorescence analysis is its application in studies of the multielemental sample of composition in a wide range of concentrations, samples with different matrices, also inhomogeneous ones and those characterized with different grain size. Typical examples of these kinds of samples are soil or geological samples for which XRF elemental analysis may be difficult due to XRF disturbing effects. In this paper the WDXRF technique was applied in elemental analysis concerning different soil and geological samples (therapeutic mud, floral soil, brown soil, sandy soil, calcium aluminum cement). The sample morphology was analyzed using X-ray microtomography technique. The paper discusses the differences between the composition of samples, the influence of procedures with respect to the preparation of samples as regards their morphology and, finally, a quantitative analysis. The results of the studies were statistically tested (one-way ANOVA and correlation coefficients). For lead concentration determination in samples of sandy soil and cement-like matrix, the WDXRF spectrometer calibration was performed. The elemental analysis of the samples was complemented with knowledge of chemical composition obtained by X-ray powder diffraction.

  13. Micrometer-scale magnetic imaging of geological samples using a quantum diamond microscope

    Science.gov (United States)

    Glenn, D. R.; Fu, R. R.; Kehayias, P.; Le Sage, D.; Lima, E. A.; Weiss, B. P.; Walsworth, R. L.

    2017-08-01

    Remanent magnetization in geological samples may record the past intensity and direction of planetary magnetic fields. Traditionally, this magnetization is analyzed through measurements of the net magnetic moment of bulk millimeter to centimeter sized samples. However, geological samples are often mineralogically and texturally heterogeneous at submillimeter scales, with only a fraction of the ferromagnetic grains carrying the remanent magnetization of interest. Therefore, characterizing this magnetization in such cases requires a technique capable of imaging magnetic fields at fine spatial scales and with high sensitivity. To address this challenge, we developed a new instrument, based on nitrogen-vacancy centers in diamond, which enables direct imaging of magnetic fields due to both remanent and induced magnetization, as well as optical imaging, of room-temperature geological samples with spatial resolution approaching the optical diffraction limit. We describe the operating principles of this device, which we call the quantum diamond microscope (QDM), and report its optimized image-area-normalized magnetic field sensitivity (20 µTṡµm/Hz1/2), spatial resolution (5 µm), and field of view (4 mm), as well as trade-offs between these parameters. We also perform an absolute magnetic field calibration for the device in different modes of operation, including three-axis (vector) and single-axis (projective) magnetic field imaging. Finally, we use the QDM to obtain magnetic images of several terrestrial and meteoritic rock samples, demonstrating its ability to resolve spatially distinct populations of ferromagnetic carriers.

  14. Determination of silver, gold, zinc and copper in mineral samples by various techniques of instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Rodriguez R, N. I.; Rios M, C.; Pinedo V, J. L.; Yoho, M.; Landsberger, S.

    2015-09-01

    Using the method of instrumental neutron activation analysis, mineral exploration samples were analyzed in order to determine the concentrations of silver, gold, zinc and copper; these minerals being the main products of benefit of Tizapa and Cozamin mines. Samples were subjected to various techniques, where the type of radiation and counting methods were chosen based on the specific isotopic characteristics of each element. For calibration and determination of concentrations the comparator method was used, certified standards were subjected to the same conditions of irradiation and measurement that the prospecting samples. The irradiations were performed at the research reactor TRIGA Mark II of the University of Texas at Austin. The silver concentrations were determined by Cyclical Epithermal Neutron Activation Analysis. This method in combination with the transfer pneumatic system allowed a good analytical precision and accuracy in prospecting for silver, from photo peak measurement 657.7 keV of short half-life radionuclide 110 Ag. For the determination of gold and zinc, Epithermal Neutron Activation Analysis was used, the photo peaks analyzed corresponded to the energies 411.8 keV of radionuclide 199 Au and 438.6 keV of metastable radionuclide 69m Zn. On the other hand, copper quantification was based on the photo peak analysis of 1039.2 keV produced by the short half-life radionuclide 66 Cu, by Thermal Neutron Activation Analysis. The photo peaks measurement corresponding to gold, zinc and copper was performed using a Compton suppression system, which allowed an improvement in the signal to noise relationship, so that better detection limits and low uncertainties associated with the results were obtained. Comparing elemental concentrations the highest values in silver, zinc and copper was for samples of mine Tizapa. Regarding gold values were found in the same range for both mines. To evaluate the precision and accuracy of the methods used, various geological

  15. Texture investigation in aluminium and iron - silicon samples by neutron diffraction technique

    International Nuclear Information System (INIS)

    Pugliese, R.; Yamasaki, J.M.

    1988-09-01

    By means of the neutron diffraction technique the texture of 5% and 98% rolled-aluminium and of iron-silicon steel used in the core of electric transformers, have been determined. The measurements were performed by using a neutron diffractometer installed at the IEA-R1 Nuclear Research Reactor, in the Beam-Hole n 0 . 6. To avoid corrections such as neutron absorption and sample luminosity the geometric form of the samples were approximated to spheric or octagonal prism, and its dimensions do not exceed that of the neutron beam. The texture of the samples were analysed with the help of a computer programme that analyses the intensity of the diffracted neutron beam and plot the pole figures. (author) [pt

  16. Ultra-high sensitivity moment magnetometry of geological samples using magnetic microscopy

    Science.gov (United States)

    Lima, Eduardo A.; Weiss, Benjamin P.

    2016-09-01

    Useful paleomagnetic information is expected to be recorded by samples with moments up to three orders of magnitude below the detection limit of standard superconducting rock magnetometers. Such samples are now detectable using recently developed magnetic microscopes, which map the magnetic fields above room-temperature samples with unprecedented spatial resolutions and field sensitivities. However, realizing this potential requires the development of techniques for retrieving sample moments from magnetic microscopy data. With this goal, we developed a technique for uniquely obtaining the net magnetic moment of geological samples from magnetic microscopy maps of unresolved or nearly unresolved magnetization. This technique is particularly powerful for analyzing small, weakly magnetized samples such as meteoritic chondrules and terrestrial silicate crystals like zircons. We validated this technique by applying it to field maps generated from synthetic sources and also to field maps measured using a superconducting quantum interference device (SQUID) microscope above geological samples with moments down to 10-15 Am2. For the most magnetic rock samples, the net moments estimated from the SQUID microscope data are within error of independent moment measurements acquired using lower sensitivity standard rock magnetometers. In addition to its superior moment sensitivity, SQUID microscope net moment magnetometry also enables the identification and isolation of magnetic contamination and background sources, which is critical for improving accuracy in paleomagnetic studies of weakly magnetic samples.

  17. Krypton and xenon in Apollo 14 samples - Fission and neutron capture effects in gas-rich samples

    Science.gov (United States)

    Drozd, R.; Hohenberg, C.; Morgan, C.

    1975-01-01

    Gas-rich Apollo 14 breccias and trench soil are examined for fission xenon from the decay of the extinct isotopes Pu-244 and I-129, and some samples have been found to have an excess fission component which apparently was incorporated after decay elsewhere and was not produced by in situ decay. Two samples have excess Xe-129 resulting from the decay of I-129. The excess is correlated at low temperatures with excess Xe-128 resulting from neutron capture on I-127. This neutron capture effect is accompanied by related low-temperature excesses of Kr-80 and Kr-82 from neutron capture on the bromine isotopes. Surface correlated concentrations of iodine and bromine are calculated from the neutron capture excesses.

  18. Natural Radioactivity in Geological Samples from Algeria by SSNTD and γ-Ray Spectrometry

    International Nuclear Information System (INIS)

    Belafrites, A.

    2009-01-01

    Results of Solid State Nuclear Track Detector (SSNTD) measurements of natural radioactivity using contact autoradiography for the determination of uranium and non-contact autoradiography for radon emanation are presented. The study is complemented by gamma -ray spectrometric results. The SSNTD method applied to geological samples has given uranium concentrations consistent with those found by gamma -ray spectrometry. The results for uranium concentration and radon emanation show excellent agreement with the few values available in other works

  19. Application of the Instrumental Neutron Activation Analysis and High Performance Liquid Chromatography (HPLC) in the rare earth elements determination in reference geological materials

    International Nuclear Information System (INIS)

    Figueiredo, Ana M.G.; Moraes, Noemia M.P. de; Shihomatsu, Helena M.

    1997-01-01

    Instrumental Neutron Activation Analysis (INAA) and High Performance Liquid Chromatography (HPLC) were applied to the determination of rare earth elements (REE) in the geological reference materials AGV-1, G-2 and GSP-1 (USGS). Results obtained by both techniques showed good agreement with certified values, giving relative errors less than 10%. The La, Ce, Nd, Sm, Eu, Tb, Yb and Lu REE elements were determined. All the REE except Dy and Y were determined by HPLC. The reference material G94, employed in the International Proficiency Test for Analytical Geochemistry Laboratories (GeoTP1) was analysed. The results obtained are a contribution to REE contents in this sample. The INAA and HPLC application to the determination of REE in this kind of matrix is also discussed. (author). 10 refs., 1 fig., 5 tabs

  20. Virtual sampling in variational processing of Monte Carlo simulation in a deep neutron penetration problem

    International Nuclear Information System (INIS)

    Allagi, Mabruk O.; Lewins, Jeffery D.

    1999-01-01

    In a further study of virtually processed Monte Carlo estimates in neutron transport, a shielding problem has been studied. The use of virtual sampling to estimate the importance function at a certain point in the phase space depends on the presence of neutrons from the real source at that point. But in deep penetration problems, not many neutrons will reach regions far away from the source. In order to overcome this problem, two suggestions are considered: (1) virtual sampling is used as far as the real neutrons can reach, then fictitious sampling is introduced for the remaining regions, distributed in all the regions, or (2) only one fictitious source is placed where the real neutrons almost terminate and then virtual sampling is used in the same way as for the real source. Variational processing is again found to improve the Monte Carlo estimates, being best when using one fictitious source in the far regions with virtual sampling (option 2). When fictitious sources are used to estimate the importances in regions far away from the source, some optimization has to be performed for the proportion of fictitious to real sources, weighted against accuracy and computational costs. It has been found in this study that the optimum number of cells to be treated by fictitious sampling is problem dependent, but as a rule of thumb, fictitious sampling should be employed in regions where the number of neutrons from the real source fall below a specified limit for good statistics

  1. Irradiation test of HAFM and tag gas samples at the standard neutron field of 'YAYOI'

    International Nuclear Information System (INIS)

    Iguchi, Tetsuo

    1997-03-01

    To check the accuracy of helium accumulation neutron fluence monitors (HAFM) as new technique for fast reactor neutron dosimetry and the applicability of tag gas activation analysis to fast reactor failed fuel detection, their samples were irradiated at the standard neutron field of the fast neutron source reactor 'YAYOI' (Nuclear Engineering Research Laboratory, University of Tokyo). Since October in 1996, the HAFM samples such as 93% enriched boron (B) powders of 1 mg and natural B powders of 10 mg contained in vanadium (V) capsule were intermittently irradiated at the reactor core center (Glory hole: Gy) and/or under the leakage neutron field from the reactor core (Fast column: FC). In addition, new V capsules filled with enriched B of 40 mg and Be of 100 mg, respectively, were put into an experimental hole through the blanket surrounding the core. These neutron fields were monitored by the activation foils consisting of Fe, Co, Ni, Au, 235 U, 237 Np etc., mainly to confirm the results obtained from 1995's preliminary works. In particular, neutron flux distributions in the vicinity of irradiated samples were measured in more detail. At the end of March in 1997, the irradiated neutron fluence have reached the goal necessary to produce the detectable number of He atoms more than ∼10 13 in each HAFM sample. Six kinds of tag gas samples, which are the mixed gases of isotopically adjusted Xe and Kr contained in SUS capsules, were separately irradiated three times at Gy under the neutron fluence of ∼10 16 n/cm 2 in average. After irradiation, γ-ray spectra were measured for each sample. Depending on the composition of tag gas mixtures, the different patterns of γ-ray peak spectra from 79 Kr, 125 Xe, etc. produced through tag gas activation were able to be clearly identified. These experimental data will be very useful for the benchmark test of tag gas activation calculation applied to the fast reactor failed fuel detection. (author)

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

    International Nuclear Information System (INIS)

    Hassan, A.M.

    2009-01-01

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

  3. Acid digestion of geological and environmental samples using open-vessel focused microwave digestion.

    Science.gov (United States)

    Taylor, Vivien F; Toms, Andrew; Longerich, Henry P

    2002-01-01

    The application of open vessel focused microwave acid digestion is described for the preparation of geological and environmental samples for analysis using inductively coupled plasma-mass spectrometry (ICP-MS). The method is compared to conventional closed-vessel high pressure methods which are limited in the use of HF to break down silicates. Open-vessel acid digestion more conveniently enables the use of HF to remove Si from geological and plant samples as volatile SiF4, as well as evaporation-to-dryness and sequential acid addition during the procedure. Rock reference materials (G-2 granite, MRG-1 gabbros, SY-2 syenite, JA-1 andesite, and JB-2 and SRM-688 basalts) and plant reference materials (BCR and IAEA lichens, peach leaves, apple leaves, Durham wheat flour, and pine needles) were digested with results comparable to conventional hotplate digestion. The microwave digestion method gave poor results for granitic samples containing refractory minerals, however fusion was the preferred method of preparation for these samples. Sample preparation time was reduced from several days, using conventional hotplate digestion method, to one hour per sample using our microwave method.

  4. Neutron activation analysis for sulphur in coal samples and moisture content by gamma-ray transmission

    International Nuclear Information System (INIS)

    Selvi, S.

    1993-01-01

    A neutron activation analysis method is described for the determination of sulphur in coal samples by analysing the beta spectrum emitted from 32 P and 33 P following the reactions 32 S(n, p) 32 P and 33 S(n, p) 33 P using 252 Cf as a source of neutrons. The transmission of the combined gamma-rays emitted from three 137 Cs and three 241 Am sources is used to measure the water content of the coal samples. (author)

  5. The Index to Marine and Lacustrine Geological Samples: Improving Sample Accessibility and Enabling Current and Future Research

    Science.gov (United States)

    Moore, C.

    2011-12-01

    The Index to Marine and Lacustrine Geological Samples is a community designed and maintained resource enabling researchers to locate and request sea floor and lakebed geologic samples archived by partner institutions. Conceived in the dawn of the digital age by representatives from U.S. academic and government marine core repositories and the NOAA National Geophysical Data Center (NGDC) at a 1977 meeting convened by the National Science Foundation (NSF), the Index is based on core concepts of community oversight, common vocabularies, consistent metadata and a shared interface. Form and content of underlying vocabularies and metadata continue to evolve according to the needs of the community, as do supporting technologies and access methodologies. The Curators Consortium, now international in scope, meets at partner institutions biennially to share ideas and discuss best practices. NGDC serves the group by providing database access and maintenance, a list server, digitizing support and long-term archival of sample metadata, data and imagery. Over three decades, participating curators have performed the herculean task of creating and contributing metadata for over 195,000 sea floor and lakebed cores, grabs, and dredges archived in their collections. Some partners use the Index for primary web access to their collections while others use it to increase exposure of more in-depth institutional systems. The Index is currently a geospatially-enabled relational database, publicly accessible via Web Feature and Web Map Services, and text- and ArcGIS map-based web interfaces. To provide as much knowledge as possible about each sample, the Index includes curatorial contact information and links to related data, information and images; 1) at participating institutions, 2) in the NGDC archive, and 3) at sites such as the Rolling Deck to Repository (R2R) and the System for Earth Sample Registration (SESAR). Over 34,000 International GeoSample Numbers (IGSNs) linking to SESAR are

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

    CERN Document Server

    Csikai, J; Sanami, T; Michikawa, T

    2002-01-01

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

  7. Neutron activation analysis of bulk samples from Chinese ancient porcelain to provenance research

    International Nuclear Information System (INIS)

    Jian Zhu; Wentao Hao; Jianming Zhen; Tongxiu Zhen; Glascock, M.D.

    2013-01-01

    Neutron activation analysis (NAA) is an important technique to determine the provenance of ancient ceramics. The most common technique used for preparing ancient samples for NAA is to grind them into a powder and then encapsulate them before neutron irradiation. Unfortunately, ceramic materials are typically very hard making it a challenge to grind them into a powder. In this study we utilize bulk porcelain samples cut from ancient shards. The bulk samples are irradiated by neutrons alongside samples that have been conventionally ground into a powder. The NAA for both the bulk samples and powders are compared and shown to provide equivalent information regarding their chemical composition. Also, the multivariate statistical have been employed to the analysis data for check the consistency. The findings suggest that NAA results are less dependent on the state of the porcelain sample, and thus bulk samples cut from shards may be used to effectively determine their provenance. (author)

  8. The method of Sample Management in Neutron Activation Analysis Laboratory-Serpong

    International Nuclear Information System (INIS)

    Elisabeth-Ratnawati

    2005-01-01

    In the testing laboratory used by neutron activation analysis method, sample preparation is the main factor and it can't be neglect. The error in the sample preparation can give result with lower accuracy. In this article is explained the scheme of sample preparation i.e sample receive administration, the separate of sample, fluid and solid sample preparation, sample grouping, irradiation, sample counting and holding the sample post irradiation. If the management of samples were good application based on Standard Operation Procedure, therefore each samples has good traceability. To optimize the management of samples is needed the trained and skilled personal and good facility. (author)

  9. Utilization of neutrons in nuclear data measurements and bulk sample analysis

    International Nuclear Information System (INIS)

    Jonah, S. A.

    1995-01-01

    Experimental investigations were carried out with neutrons in the fields of neutron data measurements and bulk sample analysis based on the interactions of neutron interactions required in the investigations together with some salient features of the sources employed are enumerated. Excitation cross section curves and isomeric cross section ratio of 58 Ni(n,p) 58 Co m , g reaction over the neutron energy range of between 5 and 15 MeV were determined using the activation analysis technique in combination with high-resolution gamma spectroscopy. Characteristics of the incident neutrons produced via the D-T reaction of a neutron generator and D-D reaction of a cyclotron were determined experimentally to account for the contributing effects of background neutrons especially in the 5-13 MeV neutron energy range where existing data are scanty and rather discrepant. The measured data agree well with calculated data using nuclear models but deviate significantly from the recommended data based on existing literature data. The measured δ act and δ m /δ g data made it possible to determine the cross section curve for 58 Ni(n,p) 58 Co m reaction. Furthermore the flux density distributions of thermal and primary fast neutrons in different configurations of bulk samples consisting of water, graphite and coal together with the attenuation characteristics were determined by the activation analysis and pulse height response spectrometry techniques. From the results obtained, an experimental geometry has been proposed for on-line elemental analysis of coal and other minerals. Similarly the total hydrogen content and 0+C/H atomic ratio in household and motor oils as well as crude oil samples of different origins were measured by an improved experimental arrangement based on the thermal neutron reflection technique. A detection limit of 0.12 w % was obtained for hydrogen indicating the possible adaptation of this technique for quality control of petroleum products

  10. Self-shielding coefficient and thermal flux depression factor of voluminous sample in neutron activation analysis

    International Nuclear Information System (INIS)

    Noorddin Ibrahim; Rosnie Akang

    2009-01-01

    Full text: One of the major problems encountered during the irradiation of large inhomogeneous samples in performing activation analysis using neutron is the perturbation of the neutron field due to absorption and scattering of neutron within the sample as well as along the neutron guide in the case of prompt gamma activation analysis. The magnitude of this perturbation shown by self-shielding coefficient and flux depression depend on several factors including the average neutron energy, the size and shape of the sample, as well as the macroscopic absorption cross section of the sample. In this study, we use Monte Carlo N-Particle codes to simulate the variation of neutron self-shielding coefficient and thermal flux depression factor as a function of the macroscopic thermal absorption cross section. The simulation works was carried out using the high performance computing facility available at UTM while the experimental work was performed at the tangential beam port of Reactor TRIGA PUSPATI, Malaysia Nuclear Agency. The neutron flux measured along the beam port is found to be in good agreement with the simulated data. Our simulation results also reveal that total flux perturbation factor decreases as the value of absorption increases. This factor is close to unity for low absorbing sample and tends towards zero for strong absorber. In addition, sample with long mean chord length produces smaller flux perturbation than the shorter mean chord length. When comparing both the graphs of self-shielding factor and total disturbance, we can conclude that the total disturbance of the thermal neutron flux on the large samples is dominated by the self-shielding effect. (Author)

  11. Self-absorption of neutron capture gamma-rays in gold samples

    International Nuclear Information System (INIS)

    Wisshak, K.; Walter, G.; Kaeppeler, F.

    1983-06-01

    The self absorption of neutron capture gamma rays in gold samples has been determined experimentally for two standard setups used in measurements of neutron capture cross sections. One makes use of an artificially collimated neutron beam and two C 6 D 6 detectors, the other of kinematically collimated neutrons and three Moxon-Rae detectors. Correction factors for an actual measurement of a neutron capture cross section using a gold standard of 1 mm thickness up to 12% were found for the first setup while they are only 4% for the second setup. The present data allow to determine the correction in an actual measurement with an accuracy of 0.5-1%. (orig.) [de

  12. Mars Sample Return: The Next Step Required to Revolutionize Knowledge of Martian Geological and Climatological History

    Science.gov (United States)

    Mittlefehldt, D. W.

    2012-01-01

    The capability of scientific instrumentation flown on planetary orbiters and landers has made great advances since the signature Viking mission of the seventies. At some point, however, the science return from orbital remote sensing, and even in situ measurements, becomes incremental, rather than revolutionary. This is primarily caused by the low spatial resolution of such measurements, even for landed instrumentation, the incomplete mineralogical record derived from such measurements, the inability to do the detailed textural, mineralogical and compositional characterization needed to demonstrate equilibrium or reaction paths, and the lack of chronological characterization. For the foreseeable future, flight instruments will suffer from this limitation. In order to make the next revolutionary breakthrough in understanding the early geological and climatological history of Mars, samples must be available for interrogation using the full panoply of laboratory-housed analytical instrumentation. Laboratory studies of samples allow for determination of parageneses of rocks through microscopic identification of mineral assemblages, evaluation of equilibrium through electron microbeam analyses of mineral compositions and structures, determination of formation temperatures through secondary ion or thermal ionization mass spectrometry (SIMS or TIMS) analyses of stable isotope compositions. Such details are poorly constrained by orbital data (e.g. phyllosilicate formation at Mawrth Vallis), and incompletely described by in situ measurements (e.g. genesis of Burns formation sediments at Meridiani Planum). Laboratory studies can determine formation, metamorphism and/or alteration ages of samples through SIMS or TIMS of radiogenic isotope systems; a capability well-beyond flight instrumentation. Ideally, sample return should be from a location first scouted by landers such that fairly mature hypotheses have been formulated that can be tested. However, samples from clastic

  13. Multi-elemental analysis of aqueous geological samples by inductively coupled plasma-optical emission spectrometry

    Science.gov (United States)

    Todorov, Todor I.; Wolf, Ruth E.; Adams, Monique

    2014-01-01

    Typically, 27 major, minor, and trace elements are determined in natural waters, acid mine drainage, extraction fluids, and leachates of geological and environmental samples by inductively coupled plasma-optical emission spectrometry (ICP-OES). At the discretion of the analyst, additional elements may be determined after suitable method modifications and performance data are established. Samples are preserved in 1–2 percent nitric acid (HNO3) at sample collection or as soon as possible after collection. The aqueous samples are aspirated into the ICP-OES discharge, where the elemental emission signals are measured simultaneously for 27 elements. Calibration is performed with a series of matrix-matched, multi-element solution standards.

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

    International Nuclear Information System (INIS)

    Stamatelatos, I.E.; Tzika, F.

    2007-01-01

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

  15. Measurement of the loss on ignition of bulk calcined bauxite samples by neutron moderation

    International Nuclear Information System (INIS)

    Aylmer, J.A.; Borsaru, M.

    1985-01-01

    The production of high-grade calcined bauxite is very dependent on the moisture content of the final product. Existing procedures rely on the ignition of small samples to monitor the effectiveness of the calcination process. The results obtained by this gravimetric technique are several hours behind production and do not permit regular adjustment of the furnace to optimize the control of the chemically bound water content (LOI). To provide rapid and more relevant results, a neutron moderation technique has been developed for measuring the LOI of bulk samples of calcined bauxite while they are still hot. The method uses fast neutrons from an 241 Am-Be neutron source to irradiate the samples, and the backscattered thermal neutrons detected are a measure of bound moisture content. The rms deviation between neutron and conventional determinations of LOI, in 15 calcined bauxite samples, was 0.08 per cent LOI over the range 0.1 to 0.9 per cent LOI. When allowance is made for the rms error in the ignition method, the error in the neutron method is found to be 0.07 per cent LOI

  16. Bulk - Samples gamma-rays activation analysis (PGNAA) with Isotopic Neutron Sources

    International Nuclear Information System (INIS)

    HASSAN, A.M.

    2009-01-01

    An overview is given on research towards the Prompt Gamma-ray Neutron Activation Analysis (PGNAA) of bulk-samples. Some aspects in bulk-sample PGNAA are discussed, where irradiation by isotopic neutron sources is used mostly for in-situ or on-line analysis. The research was carried out in a comparative and/or qualitative way or by using a prior knowledge about the sample material. Sometimes we need to use the assumption that the mass fractions of all determined elements add up to 1. The sensitivity curves are also used for some elements in such complex samples, just to estimate the exact percentage concentration values. The uses of 252 Cf, 241 Arn/Be and 239 Pu/Be isotopic neutron sources for elemental investigation of: hematite, ilmenite, coal, petroleum, edible oils, phosphates and pollutant lake water samples have been mentioned.

  17. A method to measure the diffusion coefficient by neutron wave propagation for limited samples

    International Nuclear Information System (INIS)

    Woznicka, U.

    1986-03-01

    A study has been made of the use of the neutron wave and pulse propagation method for measurement of thermal neutron diffusion parameters. Earlier works an homogenous and heterogeneous media are reviewed. A new method is sketched for the determination of the diffusion coefficient for samples of limited size. The principle is to place a relatively thin slab of the material between two blocks of a medium with known properties. The advantages and disadvantages of the method are discussed. (author)

  18. The determination of precious metals in geological samples by ICP - Mass Spectrometry

    International Nuclear Information System (INIS)

    Denoyer, E.; Ediger, R.; Hager, J.

    1989-01-01

    ICP - mass spectrometry with laser sampling has been used to determine gold directly in solid fire assay beads. A small portion of the lead bead is vaporized by Nd: YAG laser, and the resulting particulate material is passed by a flow of argon an ICP-mass spectrometer for quantitation of the gold content. Calibration with known geological materials gives linear calibration curves, and detection limits for gols are estimated to be 0.07 micrograms/gram in the original ore sample. The repeatability of the method is similar to that expected for traditional fire assay methods, and the analysis time for the solid lead bead is less than five minutes per sample. (author) [pt

  19. Feasibility studies on large sample neutron activation analysis using a low power research reactor

    International Nuclear Information System (INIS)

    Gyampo, O.

    2008-06-01

    Instrumental neutron activation analysis (INAA) using Ghana Research Reactor-1 (GHARR-1) can be directly applied to samples with masses in grams. Samples weights were in the range of 0.5g to 5g. Therefore, the representativity of the sample is improved as well as sensitivity. Irradiation of samples was done using a low power research reactor. The correction for the neutron self-shielding within the sample is determined from measurement of the neutron flux depression just outside the sample. Correction for gamma ray self-attenuation in the sample was performed via linear attenuation coefficients derived from transmission measurements. Quantitative and qualitative analysis of data were done using gamma ray spectrometry (HPGe detector). The results of this study on the possibilities of large sample NAA using a miniature neutron source reactor (MNSR) show clearly that the Ghana Research Reactor-1 (GHARR-1) at the National Nuclear Research Institute (NNRI) can be used for sample analyses up to 5 grams (5g) using the pneumatic transfer systems.

  20. Preparation of rock samples for measurement of the thermal neutron macroscopic absorption cross-section

    International Nuclear Information System (INIS)

    Czubek, J.A.; Burda, J.; Drozdowicz, K.; Igielski, A.; Kowalik, W.; Krynicka-Drozdowicz, E.; Woznicka, U.

    1986-03-01

    Preparation of rock samples for the measurement of the thermal neutron macroscopic absorption cross-section in small cylindrical two-region systems by a pulsed technique is presented. Requirements which should be fulfilled during the preparation of the samples due to physical assumptions of the method are given. A cylindrical vessel is filled with crushed rock and saturated with a medium strongly absorbing thermal neutrons. Water solutions of boric acid of well-known macroscopic absorption cross-section are used. Mass contributions of the components in the sample are specified. This is necessary for the calculation of the thermal neutron macroscopic absorption cross-section of the rock matrix. The conditions necessary for assuring the required accuracy of the measurement are given and the detailed procedure of preparation of the rock sample is described. (author)

  1. A QUANTITATIVE EVALUATION OF THE WATER DISTRIBUTION IN A SOIL SAMPLE USING NEUTRON IMAGING

    Directory of Open Access Journals (Sweden)

    Jan Šácha

    2016-10-01

    Full Text Available This paper presents an empirical method by Kang et al. recently proposed for correcting two-dimensional neutron radiography for water quantification in soil. The method was tested on data from neutron imaging of the water infiltration in a soil sample. The raw data were affected by neutron scattering and by beam hardening artefacts. Two strategies for identifying the correction parameters are proposed in this paper. The method has been further developed for the case of three-dimensional neutron tomography. In a related experiment, neutron imaging is used to record ponded-infiltration experiments in two artificial soil samples. Radiograms, i.e., two-dimensional projections of the sample, were acquired during infiltration. A calculation was made of the amount of water and its distribution within the radiograms, in the form of two-dimensional water thickness maps. Tomograms were reconstructed from the corrected and uncorrected water thickness maps to obtain the 3D spatial distribution of the water content within the sample. Without the correction, the beam hardening and the scattering effects overestimated the water content values close to the perimeter of the sample, and at the same time underestimated the values close to the centre of the sample. The total water content of the entire sample was the same in both cases. The empirical correction method presented in this study is a relatively accurate, rapid and simple way to obtain the quantitatively determined water content from two-dimensional and three-dimensional neutron images. However, an independent method for measuring the total water volume in the sample is needed in order to identify the correction parameters.

  2. Application of neutron activation analysis to trace elements determinations in lung samples

    International Nuclear Information System (INIS)

    Rogero, S.O.

    1991-01-01

    The purpose of this work was to apply the instrumental neutron activation analysis method to determine trace elements in lung samples from smokers and non smokers. Samples of lung tissues and lymph nodes from pulmonary hilum analyzed were collected from autopsies by researchers from Faculdade de Medicina da USP. (author)

  3. Field test and calibration of neutron coincidence counters for high-mass plutonium samples

    International Nuclear Information System (INIS)

    Menlove, H.O.; Dickinson, R.J.; Douglas, I.

    1987-02-01

    Five different neutron coincidence systems were evaluated and calibrated for high-mass PuO 2 samples. The samples were from 2 to 7.2 kg of PuO 2 in mass, with a large range of burnup. This report compares the equipment and the results, with an evaluation of deadtime and multiplication corrections

  4. Multicounter neutron detector for examination of content and spatial distribution of fissile materials in bulk samples

    International Nuclear Information System (INIS)

    Swiderska-Kowalczyk, M.; Starosta, W.; Zoltowski, T.

    1999-01-01

    A new neutron coincidence well-counter is presented. This experimental device can be applied for passive assay of fissile and, in particular, for plutonium bearing materials. It contains of a set of the 3 He tubes placed inside a polyethylene moderator. Outputs from the tubes, first processed by preamplifier/amplifier/discriminator circuits, are then analysed using a correlator connected with PC, and correlation techniques implemented in software. Such a neutron counter enables determination of the 240 Pu effective mass in samples of a small Pu content (i.e., where the multiplication effects can be neglected) having a fairly big volume (up to 0.17 m 3 ), if only the isotopic composition is known. For determination of neutron sources distribution inside a sample, a heuristic method based on hierarchical cluster analysis was applied. As input parameters, amplitudes and phases of two-dimensional Fourier transformation of the count profiles matrices for known point sources distributions and for the examined samples were taken. Such matrices of profiles counts are collected using the sample scanning with detection head. In the clustering processes, process, counts profiles of unknown samples are fitted into dendrograms employing the 'proximity' criterion of the examined sample profile to standard samples profiles. Distribution of neutron sources in the examined sample is then evaluated on the basis of a comparison with standard sources distributions. (author)

  5. Determination of mercury in biologycal samples by radiochemical neutron activation analysis

    International Nuclear Information System (INIS)

    Suc, N.V.

    1989-01-01

    The radiochemical neutron activation analysis was applied to determine contents of mercury in biological samples. Samples were digested in mixing of H 2 SO 4 and HNO 3 acid. After extraction of mercury by Ni-Ditiodietylphosphoric acid in carbontetrachloride, mercury was back extracted by 5% KI solution. Contents of mercury from five samples of fish was determined by this method. The accuracy of the method was checked by comparing it with NBS standard samples and results are good agreement

  6. Archive of Geosample Data and Information from the U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) Woods Hole Coastal and Marine Science Center (WHCMSC) Samples Repository

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey Coastal and Marine Geology Program (CMGP) Woods Hole Coastal and Marine Science Center (WHCMSC) Samples Repository is a partner in the...

  7. Archive of Geosample Data and Information from the U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) St. Petersburg Coastal and Marine Science Center (SPCMSC) Samples Repository

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey Coastal and Marine Geology Program (CMGP) St. Petersburg Coastal and Marine Science Center (SPCMSC) Samples Repository is a partner in the...

  8. Archive of Geosample Data and Information from the U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) Pacific Coastal and Marine Science Center (PCMSC) Samples Repository

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey Coastal and Marine Geology Program (CMGP) Pacific Coastal and Marine Science Center (PCMSC) Samples Repository is a partner in the Index...

  9. Nitrogen Detection in Bulk Samples Using a D-D Reaction-Based Portable Neutron Generator

    Directory of Open Access Journals (Sweden)

    A. A. Naqvi

    2013-01-01

    Full Text Available Nitrogen concentration was measured via 2.52 MeV nitrogen gamma ray from melamine, caffeine, urea, and disperse orange bulk samples using a newly designed D-D portable neutron generator-based prompt gamma ray setup. Inspite of low flux of thermal neutrons produced by D-D reaction-based portable neutron generator and interference of 2.52 MeV gamma rays from nitrogen in bulk samples with 2.50 MeV gamma ray from bismuth in BGO detector material, an excellent agreement between the experimental and calculated yields of nitrogen gamma rays indicates satisfactory performance of the setup for detection of nitrogen in bulk samples.

  10. A high-efficiency neutron coincidence counter for small samples

    International Nuclear Information System (INIS)

    Miller, M.C.; Menlove, H.O.; Russo, P.A.

    1991-01-01

    The inventory sample coincidence counter (INVS) has been modified to enhance its performance. The new design is suitable for use with a glove box sample-well (in-line application) as well as for use in the standard at-line mode. The counter has been redesigned to count more efficiently and be less sensitive to variations in sample position. These factors lead to a higher degree of precision and accuracy in a given counting period and allow for the practical use of the INVS counter with gamma-ray isotopics to obtain a plutonium assay independent of operator declarations and time-consuming chemicals analysis. A calculation study was performed using the Los Alamos transport code MCNP to optimize the design parameters. 5 refs., 7 figs., 8 tabs

  11. Determination of phosphorus in biological samples by thermal neutron activation followed by β--counting

    International Nuclear Information System (INIS)

    Weginwar, R.G.; Samudralwar, D.L.; Garg, A.N.

    1989-01-01

    Phosphorus was determined using the β - emitter 32 P by instrumental neutron activation analysis (INAA) in several NBS and IAEA standards, and in samples of biological origin such as human and animal blood, cancerous tissue, edible plant leaves, diets, milk samples, etc. The method involves thermal neutron irradiation (for 2-10 h in a reactor) followed by β - counting on an end-window gas flow proportional counter using aluminium filter. The results are within ±10% of the certified values in most cases. (author) 29 refs.; 3 tabs

  12. Trace aluminium determination and sampling problems of archeological bone employing destructive neutron activation analysis

    International Nuclear Information System (INIS)

    Blotcky, A.J.; Rack, E.P.; Recker, R.R.; Leffler, J.A.; Teitelbaum, S.

    1978-01-01

    A destructive neutron activation analysis procedure was developed for determining trace aluminium content in bone. The method is based on a carefully planned sample preparation, irradiation at a neutron flux for 3.1x10 11 nxcm -2 xs -1 for 5 minutes, and chemical separation based on ion exchange. It was found that bone samples soaked in aluminium containing soil gave highly elevated aluminium values as a result of the aluminium adsorption into the bone matrix. The maximum aluminium content values for prehistoric bones are larger than those of modern bones and comparable to aluminium levels present in bone from renal patients. (T.G.)

  13. Study of irradiation damage by fast neutrons in samples of Portland cement

    International Nuclear Information System (INIS)

    Lucki, G.; Rosa Junior, A.A.

    1984-01-01

    The effect of neutron irradiation in samples of Portland cement was evaluated, using the resonance frequency method and pulse velocity of ultra-sound techniques. The samples were divided in three groups: 1) monitoring samples; 2) samples submitted to gamma heating; 3) Irradiated samples. In the sample preparation, it was used the Portland Santa Rita CP 320 cement, and water-cement rate of 0.40 l/Kg. The irradiation was done in the research reactor IEA-R1, at IPEN - CNEN/SP, with an integrated flux of 7.2 x 10 18 n/cm 2 (E approx. 1 MeV). Some damage were detected, due to the neutron flux, and by the thermal effect of gamma heating. (E.G.) [pt

  14. Relationship between LIBS Ablation and Pit Volume for Geologic Samples: Applications for in situ Absolute Geochronology

    Science.gov (United States)

    Devismes, D.; Cohen, Barbara A.

    2014-01-01

    In planetary sciences, in situ absolute geochronology is a scientific and engineering challenge. Currently, the age of the Martian surface can only be determined by crater density counting. However this method has significant uncertainties and needs to be calibrated with absolute ages. We are developing an instrument to acquire in situ absolute geochronology based on the K-Ar method. The protocol is based on the laser ablation of a rock by hundreds of laser pulses. Laser Induced Breakdown Spectroscopy (LIBS) gives the potassium content of the ablated material and a mass spectrometer (quadrupole or ion trap) measures the quantity of 40Ar released. In order to accurately measure the quantity of released 40Ar in cases where Ar is an atmospheric constituent (e.g., Mars), the sample is first put into a chamber under high vacuum. The 40Arquantity, the concentration of K and the estimation of the ablated mass are the parameters needed to give the age of the rocks. The main uncertainties with this method are directly linked to the measures of the mass (typically some µg) and of the concentration of K by LIBS (up to 10%). Because the ablated mass is small compared to the mass of the sample, and because material is redeposited onto the sample after ablation, it is not possible to directly measure the ablated mass. Our current protocol measures the ablated volume and estimates the sample density to calculate ablated mass. The precision and accuracy of this method may be improved by using knowledge of the sample's geologic properties to predict its response to laser ablation, i.e., understanding whether natural samples have a predictable relationship between laser energy deposited and resultant ablation volume. In contrast to most previous studies of laser ablation, theoretical equations are not highly applicable. The reasons are numerous, but the most important are: a) geologic rocks are complex, polymineralic materials; b) the conditions of ablation are unusual (for example

  15. Preparation and characterisation of magnetic nanostructured samples for inelastic neutron scattering experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kreuzpaintner, Wolfgang

    2010-06-22

    Recent advances in thin-film structuring techniques have generated significant interest in the dynamics of spin waves in magnetic nanostructures and the possible use of inelastic neutron scattering (INS) for their investigation. This thesis describes the design and implementation, at GKSS Research Centre, of equipment for preparation of large and laterally submicron and nanometre structured magnetic samples for such future INS experiments. After a brief resume on spin waves in nanostructures, the development work on new purpose-designed equipment, including high vacuum (HV) argon ion beam milling and ultra high vacuum (UHV) e-beam evaporation setups, is described. Ni nanodot as well as Ni and novel Gd nanowire samples were prepared using combinations of sputter deposition, laser interference lithography, argon ion beam milling, e-beam evaporation and self organisation techniques. With reference to sample preparation, epitaxial growth studies for Ni on Si(100) substrate were performed, resulting in the development of a new deposition process, which by thermal tuning allows for the direct epitaxial growth of Ni on Si with unprecedented crystalline quality. The results of various characterisation experiments on the prepared nanostructured samples, including Scanning Electron Microscopy (SEM), microprobe analysis, Atomic and Magnetic Force Microscopy (AFM/MFM), Vibrating Sample Magnetometry (VSM), X-ray Diffraction (XRD) and Reflectivity (XRR), unpolarised and Polarised Neutron Scattering (PNR) and off-specular scattering by X-rays and neutrons using rocking scans and Time-Of-Flight Grazing Incidence Small Angle Neutron Scattering (TOF-GISANS), together with various analysis procedures such as Distorted-Wave Born Approximation (DWBA), are reported. The analysis of a Gd nanowire sample by TOF-GISANS led to a novel evaluation technique which in comparison with single wavelength methods allows portions of reciprocal space to be scanned without changing the angle of

  16. Preparation and characterisation of magnetic nanostructured samples for inelastic neutron scattering experiments

    International Nuclear Information System (INIS)

    Kreuzpaintner, Wolfgang

    2010-01-01

    Recent advances in thin-film structuring techniques have generated significant interest in the dynamics of spin waves in magnetic nanostructures and the possible use of inelastic neutron scattering (INS) for their investigation. This thesis describes the design and implementation, at GKSS Research Centre, of equipment for preparation of large and laterally submicron and nanometre structured magnetic samples for such future INS experiments. After a brief resume on spin waves in nanostructures, the development work on new purpose-designed equipment, including high vacuum (HV) argon ion beam milling and ultra high vacuum (UHV) e-beam evaporation setups, is described. Ni nanodot as well as Ni and novel Gd nanowire samples were prepared using combinations of sputter deposition, laser interference lithography, argon ion beam milling, e-beam evaporation and self organisation techniques. With reference to sample preparation, epitaxial growth studies for Ni on Si(100) substrate were performed, resulting in the development of a new deposition process, which by thermal tuning allows for the direct epitaxial growth of Ni on Si with unprecedented crystalline quality. The results of various characterisation experiments on the prepared nanostructured samples, including Scanning Electron Microscopy (SEM), microprobe analysis, Atomic and Magnetic Force Microscopy (AFM/MFM), Vibrating Sample Magnetometry (VSM), X-ray Diffraction (XRD) and Reflectivity (XRR), unpolarised and Polarised Neutron Scattering (PNR) and off-specular scattering by X-rays and neutrons using rocking scans and Time-Of-Flight Grazing Incidence Small Angle Neutron Scattering (TOF-GISANS), together with various analysis procedures such as Distorted-Wave Born Approximation (DWBA), are reported. The analysis of a Gd nanowire sample by TOF-GISANS led to a novel evaluation technique which in comparison with single wavelength methods allows portions of reciprocal space to be scanned without changing the angle of

  17. Determination of Hf, Sc and Y in geological samples together with the rare-earth elements

    International Nuclear Information System (INIS)

    Lihareva, N.; Delaloye, M.

    1997-01-01

    A method is described for the determination of Hf, Sc and Y simultaneously with the REE in geological materials. An earlier method for REE separation from major elements was studied with the aim to apply it also to the determination of Hf, Sc and Y. Sample decomposition was carried out by melting with LiBO 2 . The method involves separation and concentration stages, using the cation-exchange resin DOWEX AG 50W-X8. Matrix elements were eluted with 2 mol/l HCl, whereas 6 mol/l HNO 3 with oxalic acid and 8 mol/l HNO 3 were used to elute the elements to be determined. Some of the matrix elements could not be completely removed. This effect as well as the recovery rates of the determined elements were investigated. The measurements were performed by ICP-AES. Spectral interferences were also tested. (orig.). With 1 tab

  18. Preliminary petrographic description and geologic implications of the Apollo 17 Station 7 boulder consortium samples

    Science.gov (United States)

    Chao, E.C.T.; Minkin, J.A.; Thompson, C.L.

    1974-01-01

    Preliminary petrographic description and mineral composition of four hand samples (77135, 77115, 77075 and 77215) are presented. 77135, 77115, and 77075 all crystallized from fragment-laden melts; they are similar in textures but differ in grain size. 77135 and 77115 are pigeonite feldspathic basalts. On the basis of geologic and petrographic evidence, 77115 and 77075 are related; they formed, cooled, and consolidated before being engulfed in the vesicular 77135. The impact or igneous origin of the melts from which these rocks crystallized cannot be determined. 77215 is a shocked, strongly sheared and granulated microbreccia consisting of three major lithologies dominated by mineral clasts of orthopyroxene and calcic plagioclase. The orthopyroxene clasts contain coarse exsolved blebs of augite, suggesting a deep-seated origin. The major, minor, and trace element compositions of 77135, 77115, and 77075 are in general similar. They represent a major highland rock type, perhaps more important than anorthosites. ?? 1974.

  19. Automated facility for analysis of soil samples by neutron activation, counting, and data control

    International Nuclear Information System (INIS)

    Voegele, A.L.; Jesse, R.H.; Russell, W.L.; Baker, J.

    1978-01-01

    An automated facility remotely and automatically analyzes soil, water, and sediment samples for uranium. The samples travel through pneumatic tubes and switches to be first irradiated by neutrons and then counted for resulting neutron and gamma emission. Samples are loaded into special carriers, or rabbits, which are then automatically loaded into the pneumatic transfer system. The sample carriers have been previously coded with an identification number, which can be automatically read in the system. This number is used for correlating and filing data about the samples. The transfer system, counters, and identification system are controlled by a network of microprocessors. A master microprocessor initiates routines in other microprocessors assigned to specific tasks. The software in the microprocessors is unique for this type of application and lends flexibility to the system

  20. KSb(OH) samples previously treated with Co y - rays irradiated with neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Facetti, J F [Asuncion Nacional Univ. (Paraguay). Inst. de Ciencias

    1969-01-01

    When Ksb (OH) samples previously treated with Co y - rays or crushed are irradiated with neutrons, the yield of Sb and the annealing mechanism are apparently modified by the pretreatment. In addition it is shown that metastable species of Sb are formed under irradiation.

  1. Calculation of the effective D-d neutron energy distribution incident on a cylindrical shell sample

    International Nuclear Information System (INIS)

    Gotoh, Hiroshi

    1977-07-01

    A method is proposed to calculate the effective energy distribution of neutrons incident on a cylindrical shell sample placed perpendicularly to the direction of the deuteron beam bombarding a deuterium metal target. The Monte Carlo method is used and the Fortran program is contained. (auth.)

  2. Multivariate Methods for Prediction of Geologic Sample Composition with Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Morris, Richard; Anderson, R.; Clegg, S. M.; Bell, J. F., III

    2010-01-01

    Laser-induced breakdown spectroscopy (LIBS) uses pulses of laser light to ablate a material from the surface of a sample and produce an expanding plasma. The optical emission from the plasma produces a spectrum which can be used to classify target materials and estimate their composition. The ChemCam instrument on the Mars Science Laboratory (MSL) mission will use LIBS to rapidly analyze targets remotely, allowing more resource- and time-intensive in-situ analyses to be reserved for targets of particular interest. ChemCam will also be used to analyze samples that are not reachable by the rover's in-situ instruments. Due to these tactical and scientific roles, it is important that ChemCam-derived sample compositions are as accurate as possible. We have compared the results of partial least squares (PLS), multilayer perceptron (MLP) artificial neural networks (ANNs), and cascade correlation (CC) ANNs to determine which technique yields better estimates of quantitative element abundances in rock and mineral samples. The number of hidden nodes in the MLP ANNs was optimized using a genetic algorithm. The influence of two data preprocessing techniques were also investigated: genetic algorithm feature selection and averaging the spectra for each training sample prior to training the PLS and ANN algorithms. We used a ChemCam-like laboratory stand-off LIBS system to collect spectra of 30 pressed powder geostandards and a diverse suite of 196 geologic slab samples of known bulk composition. We tested the performance of PLS and ANNs on a subset of these samples, choosing to focus on silicate rocks and minerals with a loss on ignition of less than 2 percent. This resulted in a set of 22 pressed powder geostandards and 80 geologic samples. Four of the geostandards were used as a validation set and 18 were used as the training set for the algorithms. We found that PLS typically resulted in the lowest average absolute error in its predictions, but that the optimized MLP ANN and

  3. Natural radioactivity measurements in rock samples of Cuihua Mountain National Geological Park (China))

    International Nuclear Information System (INIS)

    Lu, X.; Zhang, X.

    2008-01-01

    The concentrations of the natural radionuclides namely 40 K, 232 Th and 226 Ra in rock samples collected from Cuihua Mountain National Geological Park of China have been determined using a NaI(Tl) detector. The concentrations of 226 Ra, 232 Th and 40 K in the studied rock samples range from 10.7 to 34.8, 19.9 to 53.6 and 642.7 to 1609.9 Bq kg -1 with an average of 20.4, 30.1 and 1009.5 Bq kg -1 , respectively. The concentrations of these radionuclides are compared with the typical world values. To evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity, the air absorbed dose rate, the annual effective dose rate, the representative level index and the values of both external and internal hazard indices were evaluated and compared with the internationally approved values. The radium equivalent activity values of all rock samples are lower than the limit of 370 Bq kg -1 . The values of H ex and H in are less than unity. The mean outdoor air absorbed dose rate is 69.7 nGy h -1 , and the corresponding outdoor effective dose rate is 0.086 mSv y -1 . (authors)

  4. The autoradiographic observation of neutron activated plant samples

    International Nuclear Information System (INIS)

    Koyama, Motoko; Tanizaki, Yoshiyuki

    2003-01-01

    Imaging Plate (IP) is a radiography apparatus of applying photostimulable luminescence. IP has some advantages in comparison with X-ray film, for example, high sensitivity, wide latitude and high fidelity for radiations. The high sensitivity of IP makes it possible to observe the distribution of short-lived nuclides. We obtained autoradiographs of Azuki bean cuttings. In the basal region of Azuki bean cuttings, the intensity of autoradiographs of indole acetic acid (IAA)-treated samples were higher than that of water- and Gibbereline(GA)-treated ones. The high intensity parts of IAA-treated cuttings were extended upwards. The high intensive imaging of basal region treated in IAA indicated that high elemental concentrations were in existence for adventitious root formations. The measurement results by γ-ray spectrometry showed that the Ca content in the Azuki bean cuttings basal region increased in IAA treatment. It seems that the cell division for adventitious root formation needs Ca. In Azuki bean epicotyls, Ca content showed an increase to basal region, though Mg content increased to upper region. (author)

  5. Two specialized delayed-neutron detector designs for assays of fissionable elements in water and sediment samples

    International Nuclear Information System (INIS)

    Balestrini, S.J.; Balagna, J.P.; Menlove, H.O.

    1976-01-01

    Two specialized neutron-sensitive detectors are described which are employed for rapid assays of fissionable elements by sensing for delayed neutrons emitted by samples after they have been irradiated in a nuclear reactor. The more sensitive of the two detectors, designed to assay for uranium in water samples, is 40% efficient; the other, designed for sediment sample assays, is 27% efficient. These detectors are also designed to operate under water as an inexpensive shielding against neutron leakage from the reactor and neutrons from cosmic rays. (Auth.)

  6. A method of estimating hydrogen in solid and liquid samples by means of neutron thermalisation

    International Nuclear Information System (INIS)

    Carter, D.H.; Sanders, J.E.

    1967-06-01

    The count-rate of a cadmium-covered Pu239 fission chamber placed in a reactor neutron flux increases when a hydrogen-containing material is inserted due to the thermalisation of epicadmium neutrons. This effect forms the basis of a non-destructive method of estimating hydrogen in solid or liquid samples, and trial experiments to demonstrate the principles have been made. The sensitivity is such that hydrogen down to 10 p.p.m. in a typical metal should be detected. A useful feature of the method is its very low response to elements other than hydrogen. (author)

  7. Investigation of an egyptian phosphate ore sample by neutron activation analysis technique

    International Nuclear Information System (INIS)

    Eissa, E.A.; Aly, R.A.; Rofail, N.B.; Hassan, A.M.

    1995-01-01

    A domestic phosphate ore sample has been analysed by means of prompt and delayed gamma-ray spectrometry following the activation by thermal neutron capture technique. The rabbit pneumatic transfer system (RPTS), long irradiation facility and two Pu/Be (2,5 Ci each) neutron sources set-Pu for prompt (n,gamma) were applied. The high purity germanium (HPGe) gamma-ray spectrometer with a personal computer analyzer (PCA) system were used for spectrum measurements. Programmes on the VAX computer were utilized for estimating the elemental concentrations of 22 out of 36 elements identified in this work. 2 tabs

  8. The determination of fast neutron fluence in radiation stability tests of steel samples

    International Nuclear Information System (INIS)

    Hogel, J.; Vespalec, R.

    1979-01-01

    The activation method is described of determining fast neutron fluence. Samples of steel designed for WWER type reactor pressure vessels were irradiated in the CHOUCA-rigs in the core of the WWR-S reactor. The neutron spectrum was measured by the multiple activation foil method and the effective cross sections of fluence monitors were calculated. The fluences obtained from the reactions 54 Fe(n,p) 54 Mn and 63 Cu(n,α) 60 Co are presented and the method is discussed. (author)

  9. Analysis of boron utilization in sample preparation for microorganisms detection by neutron radiography technique

    International Nuclear Information System (INIS)

    Wacha, Reinaldo; Crispim, Verginia R.

    2000-01-01

    The neutron radiography technique applied to the microorganisms detection is the study of a new and faster alternative for diagnosis of infectious means. This work presents the parameters and the effects involved in the use of the boron as a conversion agent, that convert neutrons in a particles, capable ones of generating latent tracks in a solid state nuclear tracks detector, CR-39. The collected samples are doped with the boron by the incubation method, propitiating an interaction microorganisms/boron, that will guarantee the identification of the images of those microorganisms, through your morphology. (author)

  10. Determination of short-lived trace elements in environmental samples by neutron activation analysis

    International Nuclear Information System (INIS)

    Wardani, S.; Sihombing, E.; Hamzah, A.; Rochidi; Hery, P.S.; Hartaman, S.; Iman, J.

    1998-01-01

    Concentration of a short-lived trace elements in environmental samples were determined by neutron activation analysis, a counting loss often occur due to the high counting rate. A Pile-Up Rejecter (PUR) electric circuit was installed in counting a short-lived trace elements by a γ-ray spectrometer in order to correct a counting loss. The samples were irradiated for 30∼60 seconds at neutron flux of 3.5 x 10 12 n.cm -2 .s -1 , then the samples cooled for 120 second and counted for 180 second using this system. The nuclides concentration in the varieties environmental samples have a difference analysis result, was more accurate and precise, which the measured result would be 30 % more higher by PUR system than the result would be counted using a conventional γ-ray spectrometry method

  11. Use of thermal neutron reflection method for chemical analysis of bulk samples

    International Nuclear Information System (INIS)

    Papp, A.; Csikai, J.

    2014-01-01

    Microscopic, σ β , and macroscopic, Σ β , reflection cross-sections of thermal neutrons averaged over bulk samples as a function of thickness (z) are given. The σ β values are additive even for bulk samples in the z=0.5–8 cm interval and so the σ βmol (z) function could be given for hydrogenous substances, including some illicit drugs, explosives and hiding materials of ∼1000 cm 3 dimensions. The calculated excess counts agree with the measured R(z) values. For the identification of concealed objects and chemical analysis of bulky samples, different neutron methods need to be used simultaneously. - Highlights: • Check the proposed analytical expression for the description of the flux. • Determination of the reflection cross-sections averaged over bulk samples. • Data rendered to estimate the excess counts for various materials

  12. Use of thermal neutron reflection method for chemical analysis of bulk samples

    Energy Technology Data Exchange (ETDEWEB)

    Papp, A., E-mail: papppa@atomki.hu [Institute of Nuclear Research of the Hungarian Academy of Sciences, (ATOMKI), 4001 Debrecen, Pf. 51 (Hungary); Csikai, J. [Institute of Nuclear Research of the Hungarian Academy of Sciences, (ATOMKI), 4001 Debrecen, Pf. 51 (Hungary); Institute of Experimental Physics, University Debrecen (IEP), 4010 Debrecen-10, Pf. 105 (Hungary)

    2014-09-11

    Microscopic, σ{sub β}, and macroscopic, Σ{sub β}, reflection cross-sections of thermal neutrons averaged over bulk samples as a function of thickness (z) are given. The σ{sub β} values are additive even for bulk samples in the z=0.5–8 cm interval and so the σ{sub βmol}(z) function could be given for hydrogenous substances, including some illicit drugs, explosives and hiding materials of ∼1000 cm{sup 3} dimensions. The calculated excess counts agree with the measured R(z) values. For the identification of concealed objects and chemical analysis of bulky samples, different neutron methods need to be used simultaneously. - Highlights: • Check the proposed analytical expression for the description of the flux. • Determination of the reflection cross-sections averaged over bulk samples. • Data rendered to estimate the excess counts for various materials.

  13. Analysis of medicinal plants and soil sample from Haridwar region by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Maharia, R.S.; Dutta, R.K.; Acharya, R.; Reddy, A.V.R.

    2009-01-01

    Samples of leaves and stems of four medicinal plants namely Kalmegh, Amaltas, Moalshri, and Arusa were analysed by Instrumental Neutron Activation Analysis. Soil from same location was analyzed. Though concentrations of many elements were determined in the plant samples, results of selected elements namely Na, K, Mn, Fe, Co, Cr, Zn and As are discussed in this paper. The results show that all medicinal plants analyzed have lower elemental contents except Zn compared to the soil. (author)

  14. Development of a sample environment for neutron diffraction at low temperature

    International Nuclear Information System (INIS)

    Lee, Jeong Soo; Lee, Chang Hee; Choi, Yong Nam

    2000-06-01

    This report contains the development of low temperature sample environment for the neutron diffraction and its utilization techniques. With this research, a low temperature experimental facility of T=10-300 K was developed. We measured magnetic peak of La 1 .4Sr 1 .6Mn 2 O 7 due to low temperature phase transition successfully by this unit installed at the sample table of HRPD. Therefore, the research capability for various materials under the low temperature was expanded

  15. Determination of Magnesium in Needle Biopsy Samples of Muscle Tissue by Means of Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D; Sjoeberg, H E

    1964-07-15

    Magnesium has been determined by means of neutron-activation analysis in needle biopsy samples of the order of magnitude 1 mg dry weight. The procedure applied was to extract the Mg-27 activity from irradiated muscle tissue with concentrated hydrochloric acid followed by a fast hydroxide precipitation and gamma-spectrometric measurements. The Mg activity was recovered in the muscle tissue samples to (97 {+-} 2) per cent. The sensitivity for the magnesium determination is estimated as 0.3 {mu}g.

  16. 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).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-01

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

  18. High pressure sample container for thermal neutron spectroscopy and diffraction on strongly scattering fluids

    International Nuclear Information System (INIS)

    Verkerk, P.; Pruisken, A.M.M.

    1979-01-01

    A description is presented of the construction and performance of a container for thermal neutron scattering on a fluid sample with about 1.5 cm -1 macroscopic cross section (neglecting absorption). The maximum pressure is about 900 bar. The container is made of 5052 aluminium capillary with inner diameter 0.75 mm and wall thickness 0.25 mm; it covers a neutron beam with a cross section of 9 X 2.5 cm 2 . The container has been successfully used in neutron diffraction and time-of-flight experiments on argon-36 at 120 K and several pressures up to 850 bar. It is shown that during these measurements the temperature gradient over the sample as well as the error in the absolute temperature were both less than 0.05 K. Subtraction of the Bragg peaks due to container scattering in diffraction experiments may be dfficult, but seems feasible because of the small amount of aluminium in the neutron beam. Correction for container scattering and multiple scattering in time-of-flight experiments may be difficult only in the case of coherently scattering samples and small scattering angles. (Auth.)

  19. Augmenting comprehension of geological relationships by integrating 3D laser scanned hand samples within a GIS environment

    Science.gov (United States)

    Harvey, A. S.; Fotopoulos, G.; Hall, B.; Amolins, K.

    2017-06-01

    Geological observations can be made on multiple scales, including micro- (e.g. thin section), meso- (e.g. hand-sized to outcrop) and macro- (e.g. outcrop and larger) scales. Types of meso-scale samples include, but are not limited to, rocks (including drill cores), minerals, and fossils. The spatial relationship among samples paired with physical (e.g. granulometric composition, density, roughness) and chemical (e.g. mineralogical and isotopic composition) properties can aid in interpreting geological settings, such as paleo-environmental and formational conditions as well as geomorphological history. Field samples are collected along traverses in the area of interest based on characteristic representativeness of a region, predetermined rate of sampling, and/or uniqueness. The location of a sample can provide relative context in seeking out additional key samples. Beyond labelling and recording of geospatial coordinates for samples, further analysis of physical and chemical properties may be conducted in the field and laboratory. The main motivation for this paper is to present a workflow for the digital preservation of samples (via 3D laser scanning) paired with the development of cyber infrastructure, which offers geoscientists and engineers the opportunity to access an increasingly diverse worldwide collection of digital Earth materials. This paper describes a Web-based graphical user interface developed using Web AppBuilder for ArcGIS for digitized meso-scale 3D scans of geological samples to be viewed alongside the macro-scale environment. Over 100 samples of virtual rocks, minerals and fossils populate the developed geological database and are linked explicitly with their associated attributes, characteristic properties, and location. Applications of this new Web-based geological visualization paradigm in the geosciences demonstrate the utility of such a tool in an age of increasing global data sharing.

  20. Radioisotope dilution analyses of geological samples using 236U and 229Th

    Science.gov (United States)

    Rosholt, J.N.

    1984-01-01

    The use of 236U and 229Th in alpha spectrometric measurements has some advantages over the use of other tracers and measurement techniques in isotope dilution analyses of most geological samples. The advantages are: (1) these isotopes do not occur in terrestrial rocks, (2) they have negligible decay losses because of their long half lives, (3) they cause minimal recoil contamination to surface-barrier detectors, (4) they allow for simultaneous determination of the concentration and isotopic composition of uranium and thorium in a variety of sample types, and (5) they allow for simple and constant corrections for spectral inferences, 0.5% of the 238U activity is subtracted for the contribution of 235U in the 236U peak and 1% of the 229Th activity is subtracted from the 230Th activity. Disadvantages in using 236U and 229Th are: (1) individual separates of uranium and thorium must be prepared as very thin sources for alpha spectrometry, (2) good resolution in the spectrometer system is required for thorium isotopic measurements where measurement times may extend to 300 h, and (3) separate calibrations of the 236U and 229Th spike solution with both uranium and thorium standards are required. The use of these tracers in applications of uranium-series disequilibrium studies has simplified the measurements required for the determination of the isotopic composition of uranium and thorium because of the minimal corrections needed for alpha spectral interferences. ?? 1984.

  1. Radioisotope dilution analyses of geological samples using 236U and 229Th

    International Nuclear Information System (INIS)

    Rosholt, J.N.

    1984-01-01

    The use of 236 U and 229 Th in alpha spectrometric measurements has some advantages over the use of other tracers and measurement techniques in isotope dilution analyses of most geological samples. The advantages are: 1) these isotopes do not occur in terrestrial rocks, 2) they have negligible decay losses because of their long half lives, 3) they cause minimal recoil contamination to surface-barrier detectors, 4) they allow for simultaneous determination of the concentration and isotopic composition of uranium and thorium in a variety of sample types, and 5) they allow for simple and constant corrections for spectral interferences, 0.5% of the 238 U activity is subtracted for the contribution of 235 U in the 236 U peak and 1% of the 229 Th activity is subtracted from the 230 Th activity. Disadvantages in using 236 U and 229 Th are: 1) individual separates of uranium and thorium must be prepared as very thin sources for alpha spectrometry, 2) good resolution in the spectrometer system is required for thorium isotopic measurements where measurement times may extend to 300 h, and 3) separate calibrations of the 236 U and 229 Th spike solution with both uranium and thorium standards are required. The use of these tracers in applications of uranium-series disequilibrium studies has simplified the measurements required for the determination of the isotopic composition of uranium and thorium because of the minimal corrections needed for alpha spectral interferences. (orig.)

  2. Activation measurements for thermal neutrons. Part G. Natural 36Cl production in mineral samples

    International Nuclear Information System (INIS)

    Nolte, Eckehart; Huber, Thomas; Lazarev, Vitali; Ruehm, Werner; Kato, Kazuo; Schultz, Ludolf

    2005-01-01

    In the present paper, a method was developed to calculate the contribution of natural in situ production of 36 Cl in mineral samples to the 36 Cl signal induced by the neutrons from the Hiroshima bomb. Parameters used in the calculations include local erosion rates, lithospheric depth, and elemental composition for each investigated sample. It has been shown that the calculations agree within their uncertainties with 36 Cl values measured by means of accelerator mass spectrometry, in granite samples from quarries with known locations. Both calculations and measurements suggest typical 36 Cl/Cl ratios of about 10 -13 in mineral samples. (J.P.N.)

  3. Applications of neutrons for laboratory and industrial activation analysis problems

    International Nuclear Information System (INIS)

    Szabo, Elek; Bakos, Laszlo

    1986-01-01

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

  4. Instrumental neutron activation analysis of rib bone samples and of bone reference materials

    International Nuclear Information System (INIS)

    Saiki, M.; Takata, M.K.; Kramarski, S.; Borelli, A.

    2000-01-01

    The instrumental neutron activation analysis method was used for the determination of trace elements in rib bone samples taken from autopsies of accident victims. The elements Br, Ca, Cl, Cr, Fe, Mg, Mn, Na, P, Sr, Rb and Zn were determined in cortical tissues by using short and long irradiations with thermal neutron flux of the IEA-R1m nuclear reactor. The reference materials NIST SRM 1400 Bone Ash and NIST SRM 1486 Bone Meal were also analyzed in order to evaluate the precision and the accuracy of the results. It was verified that lyophilization is the most convenient process for drying bone samples since it does not cause any element losses. Comparisons were made between the results obtained for rib samples and the literature values as well as between the results obtained for different ribs from a single individual and for bones from different individuals. (author)

  5. The use of retardion 11A8 amphoteric ion exchange resin for separation and determination of cadmium and zinc in geological and environmental materials by neutron activation analysis

    International Nuclear Information System (INIS)

    Samczynski, Z.; Dybczynski, R.

    2001-01-01

    In this work the ion exchange separation scheme with the use of amphoteric ion exchange resin Retardion 11A8 underlying the method for the determination of cadmium and zinc in geological and environmental materials by neutron activation analysis has been devised. The accuracy of the elaborated method was tested by determining Cd and Zn content in two reference materials: Lake Sediment (SL-1) of environmental and Zinnwaldite ZW-C of geological origin. The results of quantitative determinations show good agreement with the certified values. Gamma ray spectra of zinc and cadmium fractions are practically free from other activities apart from those, which are normally observed in the background. Analytical results were corrected for the blank resulting from using reagents, glassware and contact with atmosphere when isolation of analytes before neutron activation is accomplished. Considerable minimization and good reproducibility of the blank was finally achieved.(authors)

  6. k{sub 0}-INAA method at the pneumatic station of the IEA-R1 nuclear research reactor. Application to geological samples

    Energy Technology Data Exchange (ETDEWEB)

    Mariano, Davi B.; Figueiredo, Ana Maria G.; Semmler, Renato, E-mail: davimariano@usp.br, E-mail: anamaria@ipen.br, E-mail: rsemmler@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    There is a significant number of analytically important elements, when geological samples are concerned, whose activation products are short-lived (seconds to minutes) or medium-lived radioisotopes (minutes to hours). As part of the process of implementation of the k{sub 0}-INAA standardization method at the Neutron Activation Laboratory (LAN-IPEN), Sao Paulo, Brazil, this study presents the results obtained for the analysis of short and medium-lived nuclides in geological samples by k{sub 0}-INAA using the program k{sub 0}-IAEA, provided by The International Atomic Energy Agency (IAEA). The elements Al, Dy, Eu, Na, K, Mn, Mg, Sr, V and Ti were determined with respect to gold ({sup 197}Au) using the pneumatic station facility of the IEA-R1 5 MW swimming pool nuclear research reactor, Sao Paulo. Characterization of the pneumatic station was carried out by using the -bare triple-monitor- method with {sup 197}Au-{sup 96}Zr-{sup 94}Zr. The Certified Reference Material IRMM-530R Al-0,1% Au alloy, high purity zirconium, Ni and Lu comparators were irradiated. The efficiency curves of the gamma-ray spectrometer used were determined by measuring calibrated radioactive sources at the usually utilized counting geometries. The method was validated by analyzing the reference materials basalt BE-N (IWG-GIT), basalt JB- 1 (GSJ), andesite AGV-1 (USGS), granite GS-N (IWG-GIT), SOIL-7 (IAEA) and sediment Buffalo River Sediment (NIST-BRS-8704), which represent different geological matrices. The concentration results obtained agreed with certified, reference and recommended values, showing relative errors less than 10% for most elements. (author)

  7. Cryogen free high magnetic field and low temperature sample environments for neutron scattering - latest developments

    International Nuclear Information System (INIS)

    Burgoyne, John

    2016-01-01

    Continuous progress has been made over many years now in the provision of low- and ultra-low temperature sample environments, together with new high-field superconducting magnets and increased convenience for both the user and the neutron research facility via new cooling technologies. Within Oxford Instrument's experience, this has been achieved in many cases through close collaboration with neutron scientists, and with the neutron facilities' sample environment leaders in particular. Superconducting magnet designs ranging from compact Small Angle (SANS) systems up to custom-engineered wide-angle scattering systems have been continuously developed. Recondensing, or 'zero boil-off' (ZBO), systems are well established for situations in which a high field magnet is not conducive to totally cryogen free cooling solutions, and offer a reliable route with the best trade-offs of maximum system capability versus running costs and user convenience. Fully cryogen free solutions for cryostats, dilution refrigerators, and medium-field magnets are readily available. Here we will present the latest technology developments in these options, describing the state-of-the art, the relative advantages of each, and the opportunities they offer to the neutron science community. (author)

  8. The Statistics of Emission and Detection of Neutrons and Photons from Fissile Samples for Safeguard Applications

    International Nuclear Information System (INIS)

    Enqvist, Andreas

    2008-03-01

    One particular purpose of nuclear safeguards, in addition to accounting for known materials, is the detection, identifying and quantifying unknown material, to prevent accidental and clandestine transports and uses of nuclear materials. This can be achieved in a non-destructive way through the various physical and statistical properties of particle emission and detection from such materials. This thesis addresses some fundamental aspects of nuclear materials and the way they can be detected and quantified by such methods. Factorial moments or multiplicities have long been used within the safeguard area. These are low order moments of the underlying number distributions of emission and detection. One objective of the present work was to determine the full probability distribution and its dependence on the sample mass and the detection process. Derivation and analysis of the full probability distribution and its dependence on the above factors constitutes the first part of the thesis. Another possibility of identifying unknown samples lies in the information in the 'fingerprints' (pulse shape distribution) left by a detected neutron or photon. A study of the statistical properties of the interaction of the incoming radiation (neutrons and photons) with the detectors constitutes the second part of the thesis. The interaction between fast neutrons and organic scintillation detectors is derived, and compared to Monte Carlo simulations. An experimental approach is also addressed in which cross correlation measurements were made using liquid scintillation detectors. First the dependence of the pulse height distribution on the energy and collision number of an incoming neutron was derived analytically and compared to numerical simulations. Then an algorithm was elaborated which can discriminate neutron pulses from photon pulses. The resulting cross correlation graphs are analyzed and discussed whether they can be used in applications to distinguish possible sample

  9. The Statistics of Emission and Detection of Neutrons and Photons from Fissile Samples for Safeguard Applications

    Energy Technology Data Exchange (ETDEWEB)

    Enqvist, Andreas

    2008-03-15

    One particular purpose of nuclear safeguards, in addition to accounting for known materials, is the detection, identifying and quantifying unknown material, to prevent accidental and clandestine transports and uses of nuclear materials. This can be achieved in a non-destructive way through the various physical and statistical properties of particle emission and detection from such materials. This thesis addresses some fundamental aspects of nuclear materials and the way they can be detected and quantified by such methods. Factorial moments or multiplicities have long been used within the safeguard area. These are low order moments of the underlying number distributions of emission and detection. One objective of the present work was to determine the full probability distribution and its dependence on the sample mass and the detection process. Derivation and analysis of the full probability distribution and its dependence on the above factors constitutes the first part of the thesis. Another possibility of identifying unknown samples lies in the information in the 'fingerprints' (pulse shape distribution) left by a detected neutron or photon. A study of the statistical properties of the interaction of the incoming radiation (neutrons and photons) with the detectors constitutes the second part of the thesis. The interaction between fast neutrons and organic scintillation detectors is derived, and compared to Monte Carlo simulations. An experimental approach is also addressed in which cross correlation measurements were made using liquid scintillation detectors. First the dependence of the pulse height distribution on the energy and collision number of an incoming neutron was derived analytically and compared to numerical simulations. Then an algorithm was elaborated which can discriminate neutron pulses from photon pulses. The resulting cross correlation graphs are analyzed and discussed whether they can be used in applications to distinguish possible

  10. Trace and major elements in geological samples from Itingusssu River Basin, Sepetiba Bay - Rio de Janeiro

    International Nuclear Information System (INIS)

    Araripe, D.R.; Favaro, D.I.T.

    2011-01-01

    The Itingussu drainage basin is situated at 22 deg 44' - 22 deg 55' SL and 44 deg 53' - 43 deg 55' WL, in Coroa-Grande district, Sepetiba Bay, southwest of Rio de Janeiro, Brazil. Its total area is less than 10 km 2 and includes a waterfall with three drop offs. The study area is located in a granitic pre-Cambrian embasement, discharging in a mangrove forest fringe. This work attempts to investigate the influence of lithology types in the elemental composition of soil of region and sediments of related mangrove. Instrumental neutron activation analysis and subsequent gamma-ray spectrometry were used. This technique enabled the measurement of at least twenty-one chemical elements. The more representative soil samples were enriched with U and Th. Multivariate Statistical Analysis showed that the soil and sediments formed in this area have been influenced by the leucocratic rocks, enriched with LREE and Th. The factorial analysis enables the identification of five factors of influence in the ordination of elements: presence of iron minerals (biotite); presence of allanite; marine influence in the sediment; differentiated kinetic of transport and diagenesis. (author)

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

    Science.gov (United States)

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

    2018-04-01

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

  12. Elemental analysis of soil and hair sample by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Chung, Yong Sam; Quraishi, Shamshad Begum; Moon, Jong Hwa; Kim, Sun Ha; Baek, Sung Yeoil; Kang, Sang Hoon; Lim, Jong Myoung; Cho, Hyun Je; Kim, Young Jin

    2004-03-01

    Myanmar soil sample was analyzed by using the instrumental neutron activation analysis. The elemental concentrations in the sample, altogether 34 elements, Al As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Ga, Gd, Hf, Ir, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Th, Ti, V, Yb, Zn and Zr were determined. The concentration of 17 elements (Al, Au, Br, Ca, Cl, Cr, Cu, Co, Fe, Hg, K, Na, Mn, Mg, Sb, Se, Zn) in human hair samples were determined by INAA For quality control of analytical method, certified reference material was used

  13. Elemental analysis of soil and hair sample by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Sam; Quraishi, Shamshad Begum; Moon, Jong Hwa; Kim, Sun Ha; Baek, Sung Yeoil; Kang, Sang Hoon; Lim, Jong Myoung; Cho, Hyun Je; Kim, Young Jin

    2004-03-01

    Myanmar soil sample was analyzed by using the instrumental neutron activation analysis. The elemental concentrations in the sample, altogether 34 elements, Al As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Ga, Gd, Hf, Ir, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Th, Ti, V, Yb, Zn and Zr were determined. The concentration of 17 elements (Al, Au, Br, Ca, Cl, Cr, Cu, Co, Fe, Hg, K, Na, Mn, Mg, Sb, Se, Zn) in human hair samples were determined by INAA For quality control of analytical method, certified reference material was used.

  14. Automatic sample changer control software for automation of neutron activation analysis process in Malaysian Nuclear Agency

    Science.gov (United States)

    Yussup, N.; Ibrahim, M. M.; Rahman, N. A. A.; Mokhtar, M.; Salim, N. A. A.; Soh@Shaari, S. C.; Azman, A.; Lombigit, L.; Azman, A.; Omar, S. A.

    2018-01-01

    Most of the procedures in neutron activation analysis (NAA) process that has been established in Malaysian Nuclear Agency (Nuclear Malaysia) since 1980s were performed manually. These manual procedures carried out by the NAA laboratory personnel are time consuming and inefficient especially for sample counting and measurement process. The sample needs to be changed and the measurement software needs to be setup for every one hour counting time. Both of these procedures are performed manually for every sample. Hence, an automatic sample changer system (ASC) that consists of hardware and software is developed to automate sample counting process for up to 30 samples consecutively. This paper describes the ASC control software for NAA process which is designed and developed to control the ASC hardware and call GammaVision software for sample measurement. The software is developed by using National Instrument LabVIEW development package.

  15. Uranium Content in the Geological Samples of Different River Valleys in the Dauki fault Belt of Jaintiapur

    International Nuclear Information System (INIS)

    Chowdhury, Minhaz ul Islam; Ahmed Monir; Bhuiyan Abu Daiyan; Akon Eunus

    1996-01-01

    Thirty four geological samples that include six radioactive rock samples, four soil samples, two ooze samples,twelve stream-sediment samples and ten water samples, collected during a field survey in Jaintiapur area of the Dauki fault belt, oriented to the study on probable mobility of uranium either as detritus or in aquatic solution through the region, have been investigated with fluorimeter so as to find out content of uranium in the samples. The investigation aims at determining geochemical significance on uranium occurrence prevailing in the area. In general, the content of uranium in the rock samples lies in average distribution of geochemical interest. However, 194 ppm of uranium content in the gross material of the rock sample, collected from Lalakhal anomaly that records 1500 cps in situ, bears geochemical significance. But, the anomaly being associated with a cross -bedding, the presence of uranium may be inferred as an accumulation in placer sediment transported from a nearby source, Despite absence of in situ radiometric anomalies in the overall geological formations other than the Tipam and the Dupitila Sandstone members as encountered in the traverse of Sari valley , the area, in general, appears to be potential for possible occurrence of uranium. The transported stream sediments ooze and surface run-off water, as collected from the Rangapani, the Sari and even the Nayagang show geochemically significant distribution of uranium. Laboratory analyses of soil samples refers to dispersion of U bearing materials in the soil along the major channels.Uranium content in the surface run-off water of the Sari, the Rangapani and the Nayagang that have originated from the uranium bearing Meghalayan hills strongly support previous inference on mobility of uranium in aquatic solution through the geological formations of the area for possible formation of secondary uranium deposits. Eventually, prevailing geological evidences advocate that the area may be brought

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

  17. Investigation into Y-Ba-Cu-O samples by neutron scattering methods and other particles

    International Nuclear Information System (INIS)

    Lebedev, V.T.; Evmenenko, G.A.; Sibilev, A.I.; Lebedev, V.M.; Churin, S.A.

    1997-01-01

    The combination of surface-sensitive microanalysis and neutron small angle diffraction analysis as applied to a Y-Ba-Cu-O ceramic rod permits determining the composition by oxygen and heavy elements. The determination of chemical composition was accomplished as in initial ceramics so in a crystal and in transition areas. The ceramic region of the sample is shown to be nonuniform and to have a well developed granular surface [ru

  18. Epiboron instrumental neutron activation analysis for the determination of iodine in various salt samples

    International Nuclear Information System (INIS)

    Nyarko, B.J.B.; Serfor-Armah, Y.; Osae, S.; Akaho, E.H.K.; Anim-Sampong, S.; Maakuu, B.T.

    2001-01-01

    Epiboron instrumental neutron activation analysis (EINAA) using flexible boron as thermal neutron filter, has been used to analyze several salt samples obtained from various markets in Ghana for iodine. The method involves the irradiation of samples in boron carbide-lined polyethylene vials at the outer irradiation site of the Ghana Research Reactor-1 (GHARR-1). The samples were then counted directly without any pre-treatment on a Canberra N-type HPGe detector. The qualitative and quantitative analyses were done using the 443 keV photopeak of 128 I. The precision and accuracy of the method have been evaluated and the detection limits of the various samples were calculated. The values of iodine determined in the iodized salt range between 10.0 and 210 ppm. For non-iodinated salts, iodine levels were below 500 ppb. The values obtained show great variations among the salt samples, sample collection time and from market to market. This results show that the method can be successfully applied in the determination of trace amount of iodine in salt samples without any chemical separation. (author)

  19. Determination of uranium and thorium by neutron activation analysis applied to fossil samples dating

    International Nuclear Information System (INIS)

    Ticianelli, Regina B.; Figueiredo, Ana Maria Graciano; Zahn, Guilherme S.; Kinoshita, Angela; Baffa, Oswaldo

    2011-01-01

    Electron Spin Resonance (ESR) dating is based on the fact that ionizing radiation can create stable free radicals in insulating materials, like tooth enamel and bones. The concentration of these radicals - determined by ESR - is a function of the dose deposed in the sample along the years. The accumulated dose of radiation, called Archaeological Dose, is produced by the exposition to environmental radiation provided by U, Th, K and cosmic rays. If the environmental dose rate in the site where the fossil sample is found is known, it is possible to convert this dose into the age of the sample. The annual dose rate coming from the radioactive elements present in the soil and in the sample itself can be calculated by determining the U, Th and K concentration. Therefore, the determination of the dose rate depends on the concentration of these main radioactive elements. Neutron Activation Analysis has the sensitivity and the accuracy necessary to determine U, Th and K with this objective. Depending on the composition of the sample, the determination of U and Th can be improved irradiating the sample inside a Cd capsule, reducing the thermal neutron incidence on the sample and, therefore, diminishing the activation of possible interfering nuclides. In this study the optimal irradiation and counting conditions were established for U and Th determination in fossil teeth and soil. (author)

  20. Analysis of toxical element in the whitening cream cosmetic samples using neutron activation analysis (NAA)

    International Nuclear Information System (INIS)

    Th Rina M; Sunarko

    2007-01-01

    Neutron activation analysis has been done to analyze of toxical elements that is not allowed in the whitening cream cosmetic. These samples have been randomly selected from the cosmetic market. The samples were irradiated at thermal neutron flux of 10"1"33n.cm"-"2s"-"1 in the irradiation facility of rabbit system in the RSG-GAS reactor Serpong. Counting of irradiated samples have been done by a high resolution HPGe detector couple to multichannel analyzer. Data have been analyzed by GENIE 2000. The sample have been qualitatively determined up to 19 elements. These elements are: As, Br, Ce, Co, Cr, Cs, Eu, Fe, Hg, K, La, Na, Rb, Sb, Se, Sc, Rb, Th, IV, and Zn. The result of qualitative analysis showed that the toxical elements present in the samples are Hg, As, Cr and Sb with the following concentration ranges in μg/g 25.2-65.1, 1.0-6.3, 30.5-89.1 and 2.9-5.3, respectively and these element not allowed in the whitening cream cosmetic. Besides that, the others elements have been detected in the samples are Br, Fe, Zn, Sc and Co, with concentration ranges, 13.1-36.4, 65.6-159.3, 0.79-77.1, 0.5-19.5, and 6.8-31.7 μg/g, respectively, in the sample whitening cream cosmetic. (author)

  1. Multielemental determination in Citrus spp bee honey samples by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Favaro, D.I.T.; Vasconcellos, M.B.A.; Pamplona, B.

    1990-07-01

    Recently interest has grown in the determination of the concentration of inorganic chemical elements in honey bee samples, due its utilization as indicator of environmental pollution in several countries of Europe. In the present work, a method was developed to determine some essential and potentially inorganic elements in honey bee samples by intrumental neutrons activation analysis followed by high resolution gamma ray spectrometry. The honey samples were neutron irradiated during differents times at the nuclear research reactor IEA-Rl of the IPEN-CNEN/SP. The elements Na, Cl, K, Mg and Mn were determined using irradiations of 30 minutes under a thermal neutron flux of 10 12 n.cm -2 .s -1 . With 16 hours of irradiation under a flux of 10 13 n.cm -2 .s -1 and different cooling times, the elements Br, Ca, Au, Sb, Cs, Rb, Zn, Sc, Fe, Co and La were determined. The concentration of the analyzed elements ranged from ng/g to mg/g. In the future, different kinds of bee honey will be analyzed and the characteristic chemical composition of each one will be established. Based on these elemental concentration data, the relationship between the mineral composition of bee honey and its geographical origin can be studied. (author) [pt

  2. Determination of iodine 129 in environmental samples from Austria by neutron activation analysis

    International Nuclear Information System (INIS)

    Karg, V.; Schoenfeld, T.

    1986-11-01

    For various types of samples (thyroids from humans, from game and cows; ground water, snow and air filters) the 129 I-contents, expressed as 129 I/ 127 I-ratio (R), were determined by neutron activation analysis. The method utilises the neutron induced reactions 129 I(n, γ) 130 I and 127 I(n, 2n) 126 I. Four main steps are involved: 1. Separation of iodine from the sample and conversion to a form suitable for neutron irradiation. 2. Irradiation in a reactor. 3. Chemical processing of the irradiated material, i.e. separation of radio-iodine with addition of carrier. 4. Measurement of activities of 130 I and 126 I with a gammaspectrometer. The 129 I/ 127 I-ratio (R) is then obtained by comparing with the activities produced in a reference sample (usually with R = 1.0 x 10 -8 ) which is irradiated simultaneously. Details of the method are presented in the report. R-values between 0.6 x 10 -8 and 39 x 10 -8 were found. The highest values were those of snow and game thyroids. Ground water contained very little 129 I. The results confirm the expectation that 129 I enters the biosphere mainly via air and precipitation. (Author)

  3. Reactivity and neutron emission measurements of highly burnt PWR fuel rod samples

    International Nuclear Information System (INIS)

    Murphy, M.F.; Jatuff, F.; Grimm, P.; Seiler, R.; Brogli, R.; Meier, G.; Berger, H.-D.; Chawla, R.

    2006-01-01

    Fuel rods with burnup values beyond 50 GWd/t are characterised by relatively large amounts of fission products and a high abundance of major and minor actinides. Of particular interest is the change in the reactivity of the fuel as a function of burnup and the capability of modern codes to predict this change. In addition, the neutron emission from burnt fuel has important implications for the design of transport and storage facilities. Measurements have been made of the reactivity effects and the neutron emission rates of highly burnt uranium oxide and mixed oxide fuel rod samples coming from a pressurised water reactor (PWR). The reactivity measurements have been made in a PWR lattice in the PROTEUS zero-energy reactor moderated in turn with: water, a water and heavy water mixture and water containing boron. A combined transport flask and sample changer was used to insert the 400 mm long burnt fuel rod segments into the reactor. Both control rod compensation and reactor period methods were used to determine the reactivities of the samples. For the range of burnup values investigated, an interesting exponential relationship has been found between the neutron emission rate and the measured reactivity

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-08-11

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

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  6. Thermal property and density measurements of samples taken from drilling cores from potential geologic media

    International Nuclear Information System (INIS)

    Lagedrost, J.F.; Capps, W.

    1983-12-01

    Density, steady-state conductivity, enthalpy, specific heat, heat capacity, thermal diffusivity and linear thermal expansion were measured on 59 materials from core drill samples of several geologic media, including rock salt, basalt, and other associated rocks from 7 potential sites for nuclear waste isolation. The measurements were conducted from or near to room temperature up to 500 0 C, or to lower temperatures if limited by specimen cracking or fracturing. Ample documentation establishes the reliability of the property measurement methods and the accuracy of the results. Thermal expansions of salts reached 2.2 to 2.8 percent at 500 0 C. Associated rocks were from 0.6 to 1.6 percent. Basalts were close to 0.3 percent at 500 0 C. Specific heats of salts varied from 0.213 to 0.233 cal g -1 C -1 , and basalts averaged 0.239 cal g -1 C -1 . Thermal conductivities of salts at 50 0 C were from 0.022 to 0.046 wcm -1 C -1 , and at 500 0 C, from 0.012 to 0.027 wcm -1 C -1 . Basalts conductivities ranged from 0.020 to 0.022 wcm -1 C -1 at 100 0 C and 0.016 to 0.018 at 500 0 C. There were no obvious conductivity trends relative to source location. Room temperature densities of salts were from 2.14 to 2.29 gcm -3 , and basalts, from 2.83 to 2.90 gcm -3 . The extreme friability of some materials made specimen fabrication difficult. 21 references, 17 figures, 28 tables

  7. Application of thermoluminescence dating on pressed crystalline samples to determine the geological age at some areas in Eastern South, Vietnam

    International Nuclear Information System (INIS)

    Do Duy Khiem; Luu Anh Tuyen; Phan Trong Phuc; Nguyen Thi Ngoc Hue; Pham Thi Hue; La Ly Nguyen; Ha Quang Hai

    2016-01-01

    The terrestrial part of eastern margin of the Mekong Basin is formed by outcrop of the pre-Holocen Cenozoic sequence. Almost previous studies concerned in using relative methods in geologic dating at the Mekong Basin, therefore, the ages of its stratigraphy are still unclear. The thermoluminescence (TL) dating was considered as one of the precise methods in geologic dating. In our study, we used TL dating for some areas at Eastern South, Vietnam including Ba Mieu Formation and the Thu Duc Formation at some areas in Dong Nai province and Ho Chi Minh City. This work has been the first application of TL for in geologic dating by a domestic laboratory. Experimental measurements of TL were performed using pressed crystalline quartz specimens from sediment samples. The results show that the Ba Mieu Formation was deposited about 238±22 ka and the Thu Duc Formation was deposited about 199±21 ka. (author)

  8. Sample-size effects in fast-neutron gamma-ray production measurements: solid-cylinder samples

    International Nuclear Information System (INIS)

    Smith, D.L.

    1975-09-01

    The effects of geometry, absorption and multiple scattering in (n,Xγ) reaction measurements with solid-cylinder samples are investigated. Both analytical and Monte-Carlo methods are employed in the analysis. Geometric effects are shown to be relatively insignificant except in definition of the scattering angles. However, absorption and multiple-scattering effects are quite important; accurate microscopic differential cross sections can be extracted from experimental data only after a careful determination of corrections for these processes. The results of measurements performed using several natural iron samples (covering a wide range of sizes) confirm validity of the correction procedures described herein. It is concluded that these procedures are reliable whenever sufficiently accurate neutron and photon cross section and angular distribution information is available for the analysis. (13 figures, 5 tables) (auth)

  9. Phosphorus determination in bone samples by activation analysis using fast neutrons

    International Nuclear Information System (INIS)

    Madi Filho, T.; Cunha, I.I.L.

    1992-01-01

    In this report, the phosphorus determination in animal bone samples was made by means of the irradiation of samples using 14 MeV neutron generator (Van de Graaff accelerator). Induced radiation in irradiated material was measured using a NaI(Tl) detector. The method was tested in a IAEA certified standard, being obtained the values of 15,48% and 15,75%. The content of phosphorus was obtained by using two different calculating methods. Based on the experiments performed it was possible to establish a method of phosphorus analysis in bone using the Van de Graaff accelerator. (author)

  10. Determination of selenium in food matrices by replicate sample neutron activation analysis

    International Nuclear Information System (INIS)

    Ventura, M.G.; Freitas, M.C.; Ventura, M.G.; Pacheco, A.M.G.

    2009-01-01

    The replicate sample instrumental neutron activation method was optimized and used for the determination of selenium in foodstuffs. The method was reliable, yielding accurate results. Lower detections limits were obtained after each successive irradiation. Different irradiation conditions were used depending on the type of sample. For samples with higher selenium contents (meat, fish, eggs), the measured selenium in the first replicate is in all cases larger than the detection limit, but a better accuracy was obtained with a larger number of replicates (2-3 replicates). For samples with extremely low selenium contents (vegetable samples), at least seven replicates were necessary to obtain a concentration value two times larger than the detection limit. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-10-15

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-11-02

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

  14. Measurement and resonance analysis of neutron transmissions through four samples of 238U

    International Nuclear Information System (INIS)

    Olsen, D.K.; de Saussure, G.; Perez, R.B.; Difilippo, F.C.; Ingle, R.W.

    1977-01-01

    Accurate total and partial cross sections for 238 U are important for nuclear reactor design. In the resolved resonance region, energies below 4.0 keV, these cross sections are described in terms of individual resonance parameters of which the neutron widths in the 1.5 to 4.0 keV region from various workers appear discrepant. In order to determine these widths, (0.880 to 100.0 keV) neutron transmissions through 0.076, 0.254, 1.080, and 3.620 cm thick enriched 238 U samples were measured, and (0.880 to 100.0 keV) range transmissions were analyzed

  15. Application of the neutron activation analysis method for determing trace elements in Brazilian food sample

    International Nuclear Information System (INIS)

    Maihara, V.A.; Vasconcellos, M.B.A.

    1988-01-01

    Recently there has been an increase of consciousness about the importance of trace elements in human health and disease as well as rising concern about food contamination. The development of sensitive, accurate and price methods is one of the most important of the knowledge of trace elements contents in foods and in biological samples. Neutron activation analysis is one of the most suitable tecniques because a great number of elements can be determined in concentrations in the range of μg/g to ng/g. The present work is a part of an AIEA Co-ordinated Research Programme on the applications of nuclear techniques for toxic elements in foodstuffs. Neutron activation analysis is applied to analysis of bread, milk powder and rice that are considered essential foods in the Brazilian diet. Some aspects of the activation analysis of biological matrices are discussed. (author) [pt

  16. Elemental analysis of two Egyptian iron ores and produced industrial iron samples by neutron activation analysis

    International Nuclear Information System (INIS)

    Sroor, A.; Abdel-Basset, N.; Abdel-Haleem, A.S.; Hassan, A.M.

    2001-01-01

    Elemental analysis of two iron ores and initial industrial iron production prepared by the Egyptian Iron and Steel Company of Helwan near Cairo were performed by the instrumental neutron activation analysis technique. Five samples of each type were irradiated for 48 h in a thermal neutron flux of 4x10 12 n/cm 2 s in the first Egyptian research reactor ET-RR-1. Also, the Pneumatic Irradiation Rabbit System (PIRS), attached to the reactor ET-RR-1 in Inshass, was used to measure short-life elements. The γ-ray spectra were obtained with a hyper pure germanium detection system. The concentration percentage values of major, minor and trace elements are presented. Implications of the elemental concentration values obtained are presented

  17. Determination of uranium in tree bark samples by epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Lima, Nicole Pereira de; Saiki, Mitiko

    2017-01-01

    In this study uranium (U) concentrations were determined in certified reference materials (CRMs) and in tree bark samples collected in 'Cidade Universitaria Armando de Salles Oliveira' (CUASO) USP, Sao Paulo, SP, Brazil). The barks were collected from different species namely Poincianella pluviosa and Tipuana tipu. These bark samples were cleaned, dried, grated and milled for the analyses by epithermal neutron activation analysis method (ENAA). This method consists on irradiating samples and U standard in IEAR1 nuclear reactor with thermal neutron flux of 1:9 x 10 12 n cm -2 s -1 during 40 to 60 seconds depending on the samples matrices. The samples and standard were measured by gamma ray spectroscopy. U was identified by the peak of 74.66 keV of 239 U with half life of 23.47 minutes. Concentration of U was calculated by comparative method. For analytical quality control of U results, certified reference materials were analysed. Results obtained for CRMs presented good precision and accuracy, with |Z score| <= 0.39. Uranium concentrations in tree barks varied from 83.1 to 627.6 ng g - 1 and the relative standard deviations of these results ranged from 1.8 to 10%. (author)

  18. Determination of uranium in tree bark samples by epithermal neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Nicole Pereira de; Saiki, Mitiko, E-mail: mitiko@ipen.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    In this study uranium (U) concentrations were determined in certified reference materials (CRMs) and in tree bark samples collected in 'Cidade Universitaria Armando de Salles Oliveira' (CUASO) USP, Sao Paulo, SP, Brazil). The barks were collected from different species namely Poincianella pluviosa and Tipuana tipu. These bark samples were cleaned, dried, grated and milled for the analyses by epithermal neutron activation analysis method (ENAA). This method consists on irradiating samples and U standard in IEAR1 nuclear reactor with thermal neutron flux of 1:9 x 10{sup 12} n cm{sup -2} s{sup -1} during 40 to 60 seconds depending on the samples matrices. The samples and standard were measured by gamma ray spectroscopy. U was identified by the peak of 74.66 keV of {sup 239}U with half life of 23.47 minutes. Concentration of U was calculated by comparative method. For analytical quality control of U results, certified reference materials were analysed. Results obtained for CRMs presented good precision and accuracy, with |Z score| <= 0.39. Uranium concentrations in tree barks varied from 83.1 to 627.6 ng g{sup -} {sup 1} and the relative standard deviations of these results ranged from 1.8 to 10%. (author)

  19. Determination of phosphorus and calcium in biological samples by activation with 14 MeV neutrons

    International Nuclear Information System (INIS)

    Berretta, Jose Roberto

    1995-01-01

    Analytical methods for phosphorus and calcium in biological samples by means of activation with 14 MeV neutrons, using the Van de Graaff accelerator from the Instituto de Pesquisas Energeticas e Nucleares, SP, Brazil are developed. For phosphorus analysis, powder samples were pressed into pellets, weighed and transferred to polyethylene plastic envelopes. The pellets with cadmium shielding were irradiated under a fast neutron flux for 5 to 10 minutes, and further counted in a HPGe detector for 5 minutes. Calcium analysis was performed by cyclic irradiation. Samples were irradiated for 10 minutes. After a decay time of 2 minutes, gamma counting was performed for 10 minutes. After a decay time of 2 minutes, a new irradiation ws made. The irradiation cycle was repeated 5 times and the counting spectrum obtained in each cycle was accumulated in the multi channel analyser. The variation of the neutron flux was followed by using a BF 3 detector calibrated with and aluminium monitor. By means of the gamma spectrum and the neutron counting of the BF 3 detector it was possible to estimate phosphorus and calcium concentrations in the sample analyzed. The methods were checked in the reference samples from the International Atomic Energy Agency and in commercial samples of powder milk, fertilizer and animal bone. Phosphorus contents in bone (A3/74) and milk (A-11) reference materials were (15.6 +- 1.8%) and (0.9 +- 0.1)%, respectively. These values are in good agreement to the certified values (15.5 +- 0.5)% and (0.910 +- 0.102)%, respectively. Calcium analysis carried out in bone (A3/74) presented a value of (31.8+-4.1)% and the certified value was of (31.3 +- 0.3)%. Detection limits for phosphorus and calcium were determined in different analyzed samples. The agreement of the results obtained with the certified values confirmed the suitability of the methods for phosphorus and calcium analysis. The methods are fast and laborious chemical procedures are not required. (author)

  20. Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Tonsina area, Valdez Quadrangle, Alaska

    Science.gov (United States)

    Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

    2015-01-01

    The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 128 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Tonsina area in the Chugach Mountains, Valdez quadrangle, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies

  1. Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Zane Hills, Hughes and Shungnak quadrangles, Alaska

    Science.gov (United States)

    Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

    2015-01-01

    The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential.The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska.For this report, DGGS funded reanalysis of 105 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Zane Hills area in the Hughes and Shungnak quadrangles, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

  2. Laboratory electrical resistivity analysis of geologic samples from Fort Irwin, California: Chapter E in Geology and geophysics applied to groundwater hydrology at Fort Irwin, California

    Science.gov (United States)

    Bloss, Benjamin R.; Bedrosian, Paul A.

    2015-01-01

    Correlating laboratory resistivity measurements with geophysical resistivity models helps constrain these models to the geology and lithology of an area. Throughout the Fort Irwin National Training Center area, 111 samples from both cored boreholes and surface outcrops were collected and processed for laboratory measurements. These samples represent various lithologic types that include plutonic and metamorphic (basement) rocks, lava flows, consolidated sedimentary rocks, and unconsolidated sedimentary deposits that formed in a series of intermountain basins. Basement rocks, lava flows, and some lithified tuffs are generally resistive (≥100 ohm-meters [Ω·m]) when saturated. Saturated unconsolidated samples are moderately conductive to conductive, with resistivities generally less than 100 Ω·m, and many of these samples are less than 50 Ω·m. The unconsolidated samples can further be separated into two broad groups: (1) younger sediments that are moderately conductive, owing to their limited clay content, and (2) older, more conductive sediments with a higher clay content that reflects substantial amounts of originally glassy volcanic ash subsequently altered to clay. The older sediments are believed to be Tertiary. Time-domain electromagnetic (TEM) data were acquired near most of the boreholes, and, on the whole, close agreements between laboratory measurements and resistivity models were found. 

  3. Determination of organic fluorine in aqueous samples with neutron activation analysis in comparison with the DIN method

    Energy Technology Data Exchange (ETDEWEB)

    Rollinger, D. [Institut fuer Kernchemie, Universitaet Mainz, Fritz-Strassmann-Weg 2, D-55099 Mainz (Germany); Kratz, K.L. [Institut fuer Kernchemie, Universitaet Mainz, Fritz-Strassmann-Weg 2, D-55099 Mainz (Germany)

    1996-04-01

    Neutron activation analysis (NAA) has been used as detection technique for adsorbable organic fluorine in aqueous samples. The results have been compared with the standardized DIN method which uses a fluoride-ion-selective electrode (ISE). (orig.). With 3 tabs.

  4. On multielement analysis of biological samples with the aid of neutron activation

    International Nuclear Information System (INIS)

    Iyengar, G.V.

    1980-01-01

    A main objective of this study was elucidation of problems of sampling and sample preparation methods for multielement analysis of environmental and biological specimens. Another was assessment of the potentials of multielement neutron activation analysis (NAA) in environmental and biological research. In an attempt to explain the great differences in the elemental concentration ranges between biopsy and autopsy samples as reported in the literature, it was shown that post mortem changes induce great variations in the apparent elemental composition of autopsy specimens resulting in serious systematic errors. Applications of NAA to analysis of tissues of experimental animals, human tissues in health and disease, and environmental samples are illustrated with several examples. The suitability of NAA for routine analysis of elements such as Cr, Mo and Se, which are difficult to determine by other methods has been specially discussed. (author)

  5. Thermal neutron absorption cross-section for small samples (experiments in cylindrical geometry)

    International Nuclear Information System (INIS)

    Czubek, J.A.; Drozdowicz, K.; Igielski, A.; Krynicka-Drozdowicz, E.; Woznicka, U.

    1982-01-01

    Measurement results for thermal neutron macroscopic absorption cross-sections Σsub(a)1 when applying the cylindrical sample-moderator system are presented. Experiments for liquid (water solutions of H 3 BO 3 ) and solid (crushed basalts) samples are reported. Solid samples have been saturated with the H 3 BO 3 ''poisoning'' solution. The accuracy obtained for the determination of the absorption cross-section of the solid material was σ(Σsub(ma))=(1.2+2.2) c.u. in the case when porosity was measured with the accuracy of σ(phi)=0.001+0.002. The dispersion of the Σsub(ma) data obtained for basalts (taken from different quarries) was higher than the accuracy of the measurement. All experimental data for the fundamental decay constants lambda 0 together with the whole information about the samples are given. (author)

  6. Application of the neutron activation analysis method to the multielemental determination of food samples

    International Nuclear Information System (INIS)

    Maihara, V.A.

    1985-01-01

    The thermal neutron activation analysis method was applied to the determination of elements present at low concentrations and trace levels in samples of bread and milk powder using non-destructive analyses were based on gamma ray spectrometric measurements of samples and standards irradiated for periods which varied from some minutes to eight hours in a thermal neutron flux of about 10 12 n cm -2 s -1 . The concentrations obtained for milk powder were compared with the data obtained by other autors from different contries. For the bread, that comparison was not possible, because data about trace analysis in bread samples were not found. Besides, the results obtained for the various brands of bread and milk by means of non destructive and destructive analyses were compared using Student's t criterion. Some basic considerations about 'Detection Limit' were done, mainly in relation to its application in the technique used in the present work. The detection and determination limits of the trace elements analysed by destructive and non destructive techniques in bread and milk powder samples were determined using the Currie and Girardi methods. The precision of the analyses and the results obtained for the detection limits of the analysed trace elements are discussed. (Author) [pt

  7. Application of the neutron activation analysis method to the multielemental determination of food samples

    International Nuclear Information System (INIS)

    Maihara, V.A.

    1985-01-01

    The application of thermal neutron activation analysis method for determining elements presented at low concentration and level of traces in bread and dried milk samples, using non-destructive and chemical analyses, was studied. The non-destructive analyses were based on measurements of gamma spectrometry of samples and standards irradiated by thermal neutron flux on the order of 10 12 n cm -2 s -1 . The irradiation time varied from some minutes to 8 hours. The Na, Cl, Mn, Br, Fe, Zn, Rb, Sb, Cr and Sc elements in bread samples were determined. The Na, K, Cl, Ca, Mg, Br, Al, Zn, Rb, Sb and Cr elements in dried milk samples were determined. In destructive analysis, the 24 Na radioisotope was separeted by retention on hydrated antimony pentoxide column from 8N HCL after digestion of organic matter. The bread was dissolved in HNO 3 concentrated and 70% of HCLO 4 and the dried milk was dissolved in HNO 3 concentrated and H 2 O 2 . The 64 Cu, 69m Zn and 140 La radioisotopes determined. The concentrations obtained for dried milk were compared with data obtained by other authors from different contries. Basic considerations on detection limit related to its application on the technique used in this work, were done. The detection limits and trace elements using the Currie and Girardi methods were determined. The accuracy of results obtained for trace element detection limits is discussed. (Author) [pt

  8. Accuracy Enhancement of Raman Spectroscopy Using Complementary Laser-Induced Breakdown Spectroscopy (LIBS) with Geologically Mixed Samples.

    Science.gov (United States)

    Choi, Soojin; Kim, Dongyoung; Yang, Junho; Yoh, Jack J

    2017-04-01

    Quantitative Raman analysis was carried out with geologically mixed samples that have various matrices. In order to compensate the matrix effect in Raman shift, laser-induced breakdown spectroscopy (LIBS) analysis was performed. Raman spectroscopy revealed the geological materials contained in the mixed samples. However, the analysis of a mixture containing different matrices was inaccurate due to the weak signal of the Raman shift, interference, and the strong matrix effect. On the other hand, the LIBS quantitative analysis of atomic carbon and calcium in mixed samples showed high accuracy. In the case of the calcite and gypsum mixture, the coefficient of determination of atomic carbon using LIBS was 0.99, while the signal using Raman was less than 0.9. Therefore, the geological composition of the mixed samples is first obtained using Raman and the LIBS-based quantitative analysis is then applied to the Raman outcome in order to construct highly accurate univariate calibration curves. The study also focuses on a method to overcome matrix effects through the two complementary spectroscopic techniques of Raman spectroscopy and LIBS.

  9. Development and installation of an automatic sample changer for neutron activation analysis

    International Nuclear Information System (INIS)

    Domienikan, Claudio; Lapolli, Andre L.; Schoueri, Roberto M.; Moreira, Edson G.; Vasconcellos, Marina B.A.

    2013-01-01

    A Programmable and Automatic Sample Changer was built and installed at the Neutron Activation Analysis Laboratory of the Nuclear and Energy Research Institute - IPEN-CNEN/SP, Brazil. This Automatic Sample Changer allows the fully automated measurement of up to 25 samples in one run. Basically it consists of an electronic circuit and C++ program that controls the positioning of a sample holder in two axes of motion (X and Y). Each sample is transported and positioned, one by one, inside the shielding coupled to a high-purity germanium (HPGe) radiation detector. A Canberra DSA-1000 Multichannel Analyzer coupled to the Genie 2000 software performs the data acquisition for analysis of the samples. When the counting is finished the results are saved in a hard disk of a PC computer. The sample is brought back by the sample holder to its initial position, and the next sample is carried to the shielding. The Sample Changer was designed and constructed at IPEN-CNEN/SP by employing national components and expertise. (author)

  10. Calculation of the distribution of the escaping from a fissionable sample neutrons number when introducing one fission neutron in that sample

    International Nuclear Information System (INIS)

    Dorlet, J.

    1991-01-01

    A describing algorithm furnishes the probabilities of having exactly N escaping neutrons in the descent of one fission neutron, using the punctual reactor model. Calculations can be performed even for N-values greater than 1000. Numerical results show that discrete neutrons counting is unfit to obtain the N mean value, even for very far subcritical devices. That mean value is still very used in the existing theoretical studies, because its obvious correlation with the device effective multiplication coefficient. For that reason modelling coincidence neutrons counting is not suitable using statistical moments approach, but only using probabilities it selves [fr

  11. Development of Large Sample Neutron Activation Technique for New Applications in Thailand

    International Nuclear Information System (INIS)

    Laoharojanaphand, S.; Tippayakul, C.; Wonglee, S.; Channuie, J.

    2018-01-01

    The development of the Large Sample Neutron Activation Analysis (LSNAA) in Thailand is presented in this paper. The technique had been firstly developed with rice sample as the test subject. The Thai Research Reactor-1/Modification 1 (TRR-1/M1) was used as the neutron source. The first step was to select and characterize an appropriate irradiation facility for the research. An out-core irradiation facility (A4 position) was first attempted. The results performed with the A4 facility were then used as guides for the subsequent experiments with the thermal column facility. The characterization of the thermal column was performed with Cu-wire to determine spatial distribution without and with rice sample. The flux depression without rice sample was observed to be less than 30% while the flux depression with rice sample increased to within 60%. The flux monitors internal to the rice sample were used to determine average flux over the rice sample. The gamma selfshielding effect during gamma measurement was corrected using the Monte Carlo simulation. The ratio between the efficiencies of the volume source and the point source for each energy point was calculated by the MCNPX code. The research team adopted the k0-NAA methodology to calculate the element concentration in the research. The k0-NAA program which developed by IAEA was set up to simulate the conditions of the irradiation and measurement facilities used in this research. The element concentrations in the bulk rice sample were then calculated taking into account the flux depression and gamma efficiency corrections. At the moment, the results still show large discrepancies with the reference values. However, more research on the validation will be performed to identify sources of errors. Moreover, this LS-NAA technique was introduced for the activation analysis of the IAEA archaeological mock-up. The results are provided in this report. (author)

  12. Evaluation of dynamic elasticity module in samples of Portland (type 1) cement paste exposed to neutronic irradiation

    International Nuclear Information System (INIS)

    Rosa Junior, A.A.; Lucki, G.

    1986-01-01

    The fast neutron radiation effects and temperature on Portland cement are studied. The Dynamic Elasticity Module (Ed) in samples of Portland cement paste was evaluated. Ultrassonic technics were applied (resonance frequency and pulse velocity). The samples were irradiated with fast neutrons to fluence of 7,2 x 10 18 n/cm 2 (E approx. 1 MeV), at temperature of 120 + - 5 0 C, due to gamma heating. This temperature was simulated in laboratory in a microwave oven. (Author) [pt

  13. A neutron multiplicity analysis method for uranium samples with liquid scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hao, E-mail: zhouhao_ciae@126.com [China Institute of Atomic Energy, P.O.BOX 275-8, Beijing 102413 (China); Lin, Hongtao [Xi' an Reasearch Institute of High-tech, Xi' an, Shaanxi 710025 (China); Liu, Guorong; Li, Jinghuai; Liang, Qinglei; Zhao, Yonggang [China Institute of Atomic Energy, P.O.BOX 275-8, Beijing 102413 (China)

    2015-10-11

    A new neutron multiplicity analysis method for uranium samples with liquid scintillators is introduced. An active well-type fast neutron multiplicity counter has been built, which consists of four BC501A liquid scintillators, a n/γdiscrimination module MPD-4, a multi-stop time to digital convertor MCS6A, and two Am–Li sources. A mathematical model is built to symbolize the detection processes of fission neutrons. Based on this model, equations in the form of R=F*P*Q*T could be achieved, where F indicates the induced fission rate by interrogation sources, P indicates the transfer matrix determined by multiplication process, Q indicates the transfer matrix determined by detection efficiency, T indicates the transfer matrix determined by signal recording process and crosstalk in the counter. Unknown parameters about the item are determined by the solutions of the equations. A {sup 252}Cf source and some low enriched uranium items have been measured. The feasibility of the method is proven by its application to the data analysis of the experiments.

  14. Characterization of mono-ethylene-glycol based industrial polyurethanes samples by fast-neutron radiography and neutron tomography

    Science.gov (United States)

    Rogante, Massimo; Söllradl, Stefan

    2016-09-01

    A complicated structural organization of polyurethanes may have a strong influence on the materials functional properties. Under particular conditions such as mechanical and thermal loading and aging, it leads to the material degradation, even in fresh-prepared bulk polymers and especially if defects are present in the material. Unwanted bubbles can be observed, which form during the expansion of the mixture during its chemical reaction and remain present in the final product. These macro-, micro- and nano-bubbles influence the material's performance. In this work, neutron radiography and tomography have been adopted to characterize at a macro-scale level the bulk of commercially available polyurethane samples, obtained from dissimilar- mixture ratios with different densities and branching levels as well as from different zones of the production mould. The characterisation allowed an estimation of the different dense materials - as they are used, e.g., in soles of shoes - as well as the invisible defects like pores and cracks, responsible for the materials fracture by mechanical loading. The obtained information are expected to be useful for various industrial sectors such as automotive and footwear industry. It will be completed by applying SANS, which has already proved to characterize the microstructure of the bulk-polymer with respect to nano-pores, micro-cracks and their arrangement in the polymer matrix.

  15. Characterization of mono-ethylene-glycol based industrial polyurethanes samples by fast-neutron radiography and neutron tomography

    International Nuclear Information System (INIS)

    Rogante, Massimo; Söllradl, Stefan

    2016-01-01

    A complicated structural organization of polyurethanes may have a strong influence on the materials functional properties. Under particular conditions such as mechanical and thermal loading and aging, it leads to the material degradation, even in fresh-prepared bulk polymers and especially if defects are present in the material. Unwanted bubbles can be observed, which form during the expansion of the mixture during its chemical reaction and remain present in the final product. These macro-, micro- and nano-bubbles influence the material's performance. In this work, neutron radiography and tomography have been adopted to characterize at a macro-scale level the bulk of commercially available polyurethane samples, obtained from dissimilar- mixture ratios with different densities and branching levels as well as from different zones of the production mould. The characterisation allowed an estimation of the different dense materials - as they are used, e.g., in soles of shoes - as well as the invisible defects like pores and cracks, responsible for the materials fracture by mechanical loading. The obtained information are expected to be useful for various industrial sectors such as automotive and footwear industry. It will be completed by applying SANS, which has already proved to characterize the microstructure of the bulk-polymer with respect to nano-pores, micro-cracks and their arrangement in the polymer matrix. (paper)

  16. The feasibility of TEA CO2 laser-induced plasma for spectrochemical analysis of geological samples in simulated Martian conditions

    Science.gov (United States)

    Savovic, Jelena; Stoiljkovic, Milovan; Kuzmanovic, Miroslav; Momcilovic, Milos; Ciganovic, Jovan; Rankovic, Dragan; Zivkovic, Sanja; Trtica, Milan

    2016-04-01

    The present work studies the possibility of using pulsed Transversely Excited Atmospheric (TEA) carbon dioxide laser as an energy source for laser-induced breakdown spectroscopy (LIBS) analysis of rocks under simulated Martian atmospheric conditions. Irradiation of a basaltic rock sample with the laser intensity of 56 MW cm- 2, in carbon-dioxide gas at a pressure of 9 mbar, created target plasma with favorable conditions for excitation of all elements usually found in geological samples. Detection limits of minor constituents (Ba, Cr, Cu, Mn, Ni, Sr, V, and Zr) were in the 3 ppm-30 ppm range depending on the element. The precision varied between 5% and 25% for concentration levels of 1% to 10 ppm, respectively. Generally, the proposed relatively simple TEA CO2 laser-LIBS system provides good sensitivity for geological studies under reduced CO2 pressure.

  17. Different methodologies in neutron activation to approach the full analysis of environmental and nutritional samples

    International Nuclear Information System (INIS)

    Freitas, M.C.; Dionisio, I.; Dung, H.M.

    2008-01-01

    Different methodologies of neutron activation analysis (NAA) are now available at the Technological and Nuclear Institute (Sacavem, Portugal), namely Compton suppression, epithermal activation, replicate and cyclic activation, and low energy photon measurement. Prompt gamma activation analysis (PGAA) will be implemented soon. Results by instrumental NAA and PGAA on environmental and nutritional samples are discussed herein, showing that PGAA - carried out at the Institute of Isotope Research (Budapest, Hungary) - brings about an effective input to assessing relevant elements. Sensitivity enhancement in NAA by Compton suppression is also illustrated. Through a judicious combination of methodologies, practically all elements of interest in pollution and nutrition terms can be determined. (author)

  18. Data analysis of a polycrystalline nickel sample obtained with neutron diffraction

    International Nuclear Information System (INIS)

    Parente, C.B.R.; Mazzochi, V.L.; Araujo Kaschny, J.R. de; Costa, M.S. da; Rizzo, P.; Campos, W.M.S.

    1990-01-01

    A simple analysis of the nickel structure was made. Neutron diffraction data were used, obtained with polycrystalline nickel placed in a cylindrical sample-holder with dimensions of 1,5cm of diameter and 5cm of height. The theoretical intensities were calculated of 3 forms: 1. without considering the temperature and obsorption effects, 2. considering only the temperature effect and 3. considering both the temperature and absorption effects. The disagreement factors found in this 3 cases were, respectively, R 1 = 13.4%, R 2 = 7,7% e R 3 = 7,5%. (L.C.)

  19. Rare earths analysis of rock samples by instrumental neutron activation analysis, internal standard method

    International Nuclear Information System (INIS)

    Silachyov, I.

    2016-01-01

    The application of instrumental neutron activation analysis for the determination of long-lived rare earth elements (REE) in rock samples is considered in this work. Two different methods are statistically compared: the well established external standard method carried out using standard reference materials, and the internal standard method (ISM), using Fe, determined through X-ray fluorescence analysis, as an element-comparator. The ISM proved to be the more precise method for a wide range of REE contents and can be recommended for routine practice. (author)

  20. Determination of phosphorus in wheat grass samples by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Kulkarni, S.D.; Rajurkar, N.S.; Acharya, R.; Nair, A.G.C.; Reddy, A.V.R.

    2005-01-01

    An instrumental neutron activation analysis (INAA) method using β-counting was used to determine phosphorus in wheat grass; grown in three different conditions. The phosphorus concentration was found to be in the range of 950-23000 mg/g in the samples grown in different conditions. The accuracy of the method was evaluated by determining phosphorus in three reference materials and the % deviations were within 10%. Reliability of the method was checked by following the half-life of the 32 P. (author)

  1. Neutron activation analysis of chemical impurities in manipulated samples of omeprazole

    Energy Technology Data Exchange (ETDEWEB)

    Sepe, Fernanda Peixoto; Leal, Alexandre Soares; Gomes, Tatiana Cristina Bomfim; Menezes, Maria Angela de Barros Correia; Silva, Maria Aparecida, E-mail: asleal@cdtn.br [Nuclear Technology Development Centre/Brazilian Commission for Nuclear Energy (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    In this work, samples of Omeprazole (C{sub 17}H{sub 19}N{sub 3}O{sub 3}S), a largely used drug in the treatment of dyspepsia and peptic ulcer, were acquired from five different pharmacies of manipulation - or retail pharmacies which prepare personalized drugs under medical recommendation - in Belo Horizonte/Brazil and investigated using the k{sub 0} - Neutron Activation Analysis (NAA). The preliminary results showed the presence of elements not foreseen in the original formula. It confirms the potential risk offered by medicines without suitable inspection. (author)

  2. Neutron activation analysis of chemical impurities in manipulated samples of omeprazole

    International Nuclear Information System (INIS)

    Sepe, Fernanda Peixoto; Leal, Alexandre Soares; Gomes, Tatiana Cristina Bomfim; Menezes, Maria Angela de Barros Correia; Silva, Maria Aparecida

    2011-01-01

    In this work, samples of Omeprazole (C 17 H 19 N 3 O 3 S), a largely used drug in the treatment of dyspepsia and peptic ulcer, were acquired from five different pharmacies of manipulation - or retail pharmacies which prepare personalized drugs under medical recommendation - in Belo Horizonte/Brazil and investigated using the k 0 - Neutron Activation Analysis (NAA). The preliminary results showed the presence of elements not foreseen in the original formula. It confirms the potential risk offered by medicines without suitable inspection. (author)

  3. Procedural and developmental aspects of a multielement automatic radiochemical machine, applied to neutron irradiated biomedical samples

    International Nuclear Information System (INIS)

    Iyengar, G.V.

    1976-06-01

    This report is intended to serve as a practical guide, elaborately describing the working details and some developmental work connected with an automatic multielement radiochemical machine based on thermal neutron activation analysis using ion exchange and partition chromatography. Some of the practical aspects and personal observations after much experience with this versatile multielement method, applied to investigate the elemental composition of different biomedical matrices, are summarized. Standard reference materials are analyzed, and the data are presented with a set of gamma-spectra obtained before and after chemical separation into convenient groups suitable for gamma spectroscopy. The samples analyzed included various human and animal tissues, body fluids, IAEA biological standard reference materials, and samples from the WHO/IAEA project on 'Trace elements in relation to cardiovascular diseases'. Simplified modifications of the radiochemical processing, suitable for fast and routine analysis of clinical samples have also been discussed. (orig.) [de

  4. The Importance of Mars Samples in Constraining the Geological and Geophysical Processes on Mars and the Nature of its Crust, Mantle, and Core

    Science.gov (United States)

    iMOST Team; Herd, C. D. K.; Ammannito, E.; Anand, M.; Debaille, V.; Hallis, L. J.; McCubbin, F. M.; Schmitz, N.; Usui, T.; Weiss, B. P.; Altieri, F.; Amelin, Y.; Beaty, D. W.; Benning, L. G.; Bishop, J. L.; Borg, L. E.; Boucher, D.; Brucato, J. R.; Busemann, H.; Campbell, K. A.; Carrier, B. L.; Czaja, A. D.; Des Marais, D. J.; Dixon, M.; Ehlmann, B. L.; Farmer, J. D.; Fernandez-Remolar, D. C.; Fogarty, J.; Glavin, D. P.; Goreva, Y. S.; Grady, M. M.; Harrington, A. D.; Hausrath, E. M.; Horgan, B.; Humayun, M.; Kleine, T.; Kleinhenz, J.; Mangold, N.; Mackelprang, R.; Mayhew, L. E.; McCoy, J. T.; McLennan, S. M.; McSween, H. Y.; Moser, D. E.; Moynier, F.; Mustard, J. F.; Niles, P. B.; Ori, G. G.; Raulin, F.; Rettberg, P.; Rucker, M. A.; Sefton-Nash, E.; Sephton, M. A.; Shaheen, R.; Shuster, D. L.; Siljestrom, S.; Smith, C. L.; Spry, J. A.; Steele, A.; Swindle, T. D.; ten Kate, I. L.; Tosca, N. J.; Van Kranendonk, M. J.; Wadhwa, M.; Werner, S. C.; Westall, F.; Wheeler, R. M.; Zipfel, J.; Zorzano, M. P.

    2018-04-01

    We present the main sample types from any potential Mars Sample Return landing site that would be required to constrain the geological and geophysical processes on Mars, including the origin and nature of its crust, mantle, and core.

  5. Precise simultaneous determination of zirconium and hafnium in silicate rocks, meteorites and lunar samples. [Neutron reactions

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P A; Garg, A N; Ehmann, W D [Kentucky Univ., Lexington (USA). Dept. of Chemistry

    1977-01-01

    A precise, sensitive and rapid analytical technique has been developed for the simultaneous determination of Zr and Hf in natural silicate matrices. The technique is based on radiochemical neutron activation analysis and employs a rapid fusion dissolution of the sample and simultaneous precipitation of the Zr-Hf pair with p-hydroxybenzene arsenic acid in an acidic medium. The indicator radionuclides, /sup 95/Zr and /sup 181/Hf, are counted and the /sup 95/Zr activity is corrected for the contribution from U fission. The chemical yields of the radiochemical separation are based on Hf carrier. The yield is determined by reactivation of the processed samples and standards with a /sup 252/Cf isotopic neutron source and by counting the 18.6 sec half-life sup(179m)Hf. The RNAA procedure for Zr and Hf has been shown to be precise and accurate for natural silicate samples, based on replicate analyses of samples containing Zr in the range of 1 ..mu..g/g to over 600 ..mu..g/g. The procedure is relatively rapid with a total chemical processing time of approximately 3 hours. At least 4 samples are processed simultaneously. Ten additional elements (Fe, Cr, Co, Sc, Eu, La, Lu, Ce, Th and Tb) can be determined by direct Ge(Li) spectrometry (INAA) on the samples prior to dissolution for the RNAA determination of Zr and Hf. Corrections for the U fission contribution can be made on the basis of the known U content or from the INAA Th content, based on the relatively constant natural Th/U ratio.

  6. Neutron multicounter detector for investigation of content and spatial distribution of fission materials in large volume samples

    International Nuclear Information System (INIS)

    Swiderska-Kowalczyk, M.; Starosta, W.; Zoltowski, T.

    1998-01-01

    The experimental device is a neutron coincidence well counter. It can be applied for passive assay of fissile - especially for plutonium bearing - materials. It consist of a set of 3 He tubes placed inside a polyethylene moderator; outputs from the tubes, first processed by preamplifier/amplifier/discriminator circuits, are then analysed using neutron correlator connected with a PC, and correlation techniques implemented in software. Such a neutron counter allows for determination of plutonium mass ( 240 Pu effective mass) in nonmultiplying samples having fairly big volume (up to 0.14 m 3 ). For determination of neutron sources distribution inside the sample, the heuristic methods based on hierarchical cluster analysis are applied. As an input parameters, amplitudes and phases of two-dimensional Fourier transformation of the count profiles matrices for known point sources distributions and for the examined samples, are taken. Such matrices are collected by means of sample scanning by detection head. During clustering process, counts profiles for unknown samples fitted into dendrograms using the 'proximity' criterion of the examined sample profile to standard samples profiles. Distribution of neutron sources in an examined sample is then evaluated on the basis of comparison with standard sources distributions. (author)

  7. Trace elemental characterisation of different Indian tea samples by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Lagad, Rupali A.; Alamelu, D.; Aggarwal, S.K.; Acharya, R.

    2010-01-01

    Determination of elemental content of different food materials is of importance since excess or deficiency of some of the elements have direct consequence to health of human beings. Tea is a common beverage consumed widely in India. India is one of the major country where good quality tea is produced. The tea plants are grown over a wide region of the country. It was of interest to study the elemental composition in tea samples from different geographical locations and to develop a suitable methodology to identify the geographical origin from the trace element profiles. With this objective, about 40 tea samples (both from plantations as well as from market) from the different locations in India viz. Assam, Munnar, Himachal Pradesh and Darjeeling were analyzed by INAA. About 150 mg of each of the sample packed in aluminium foil was irradiated in the self serve position of CIRUS reactor, BARC, for 3 to 5 hours at a neutron flux of ∼10 13 cm -2 s -1 . Along with the samples, Certified Reference Materials (CRMs) GBS-7(Tea leaves, as reference standard) and SRM-1515 (Apple leaves as control sample) were irradiated. Radioactive assay of the irradiated samples were carried out using a 40% relative efficiency HPGe detector coupled to 8K MCA and gamma-ray spectra were recorded for sufficient time for obtaining good counting statistics. Peak areas were determined using a peak-fit software PHAST. Concentrations of the different elements in tea samples were determined using relative method of INAA

  8. Determination of sodium in biological samples by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Parwate, D.V.; Garg, A.N.

    1981-01-01

    Sodium is one of the most essential elements needed for metabolic processes amongst human beings. It is consumed in the form of sodium chloride but it is also present in edible plant leaves. Sodium is mostly analyzed by flame photometric method, a destructive and time consuming technique. Sodium has been determined in some green leave vegetables samples-palak, radish, khatta palak (ambat chuka), chaulai leaves, chauli bean covers and its seeds by instrumental neutron activation analysis. The method involves irradiation of samples with thermal neutrons from 241 Am-Be source and counting 24 Na activity (half life 15 hr) from the reaction 23 Na(n,γ) 24 Na. Activity due to 1.37 MeV photopeak was counted with a NaI(Tl) crystal coupled to gamma ray spectrometer. Green leaves of the vegetables were thoroughly washed, dried at constant temperature and powdered. Bowen's Kale powder was used as standard for measuring sodium abundances. About 2g each of samples and the standard were packed in polythene vials. They were irradiated for 24 hrs, delayed by 1 hr and then counted for 20 mts. It is found that radish leaves are most enriched in sodium (14.0 +-0.45%) amongst four leave samples analyzed. For three different parts of chaulai leaves, bean covers and seeds, sodium contents are 1.38%, 1820 and 1010 ppm. Palak contains 2.84 +-0.29% while khatta palak contains only 4210 +- 830 ppm sodium. All values reported here are for dry weight samples and are means of three replicate measurements with standard deviation. (author)

  9. Optimization of multi-channel neutron focusing guides for extreme sample environments

    International Nuclear Information System (INIS)

    Di Julio, D D; Lelièvre-Berna, E; Andersen, K H; Bentley, P M; Courtois, P

    2014-01-01

    In this work, we present and discuss simulation results for the design of multichannel neutron focusing guides for extreme sample environments. A single focusing guide consists of any number of supermirror-coated curved outer channels surrounding a central channel. Furthermore, a guide is separated into two sections in order to allow for extension into a sample environment. The performance of a guide is evaluated through a Monte-Carlo ray tracing simulation which is further coupled to an optimization algorithm in order to find the best possible guide for a given situation. A number of population-based algorithms have been investigated for this purpose. These include particle-swarm optimization, artificial bee colony, and differential evolution. The performance of each algorithm and preliminary results of the design of a multi-channel neutron focusing guide using these methods are described. We found that a three-channel focusing guide offered the best performance, with a gain factor of 2.4 compared to no focusing guide, for the design scenario investigated in this work.

  10. Uncertainty Estimation of Neutron Activation Analysis in Zinc Elemental Determination in Food Samples

    International Nuclear Information System (INIS)

    Endah Damastuti; Muhayatun; Diah Dwiana L

    2009-01-01

    Beside to complished the requirements of international standard of ISO/IEC 17025:2005, uncertainty estimation should be done to increase quality and confidence of analysis results and also to establish traceability of the analysis results to SI unit. Neutron activation analysis is a major technique used by Radiometry technique analysis laboratory and is included as scope of accreditation under ISO/IEC 17025:2005, therefore uncertainty estimation of neutron activation analysis is needed to be carried out. Sample and standard preparation as well as, irradiation and measurement using gamma spectrometry were the main activities which could give contribution to uncertainty. The components of uncertainty sources were specifically explained. The result of expanded uncertainty was 4,0 mg/kg with level of confidence 95% (coverage factor=2) and Zn concentration was 25,1 mg/kg. Counting statistic of cuplikan and standard were the major contribution of combined uncertainty. The uncertainty estimation was expected to increase the quality of the analysis results and could be applied further to other kind of samples. (author)

  11. Improving neutron multiplicity counting for the spatial dependence of multiplication: Results for spherical plutonium samples

    Energy Technology Data Exchange (ETDEWEB)

    Göttsche, Malte, E-mail: malte.goettsche@physik.uni-hamburg.de; Kirchner, Gerald

    2015-10-21

    The fissile mass deduced from a neutron multiplicity counting measurement of high mass dense items is underestimated if the spatial dependence of the multiplication is not taken into account. It is shown that an appropriate physics-based correction successfully removes the bias. It depends on four correction coefficients which can only be exactly determined if the sample geometry and composition are known. In some cases, for example in warhead authentication, available information on the sample will be very limited. MCNPX-PoliMi simulations have been performed to obtain the correction coefficients for a range of spherical plutonium metal geometries, with and without polyethylene reflection placed around the spheres. For hollow spheres, the analysis shows that the correction coefficients can be approximated with high accuracy as a function of the sphere's thickness depending only slightly on the radius. If the thickness remains unknown, less accurate estimates of the correction coefficients can be obtained from the neutron multiplication. The influence of isotopic composition is limited. The correction coefficients become somewhat smaller when reflection is present.

  12. Determination of iodine in biological samples by neutron activation analysis (NAA)

    International Nuclear Information System (INIS)

    Geetha, P.V.; Karunakara, N.; Prabhu, Ujwal; Yashodhara, I.; Ravi, P.M.; Sudhakar, J.; Ajith, Nicy; Swain, K.K.; Verma, R.; Reddy, A.V.R.; Acharya, R.

    2010-01-01

    During normal operating conditions of a nuclear reactor, the release of radionuclides to the environment will be extremely low and well within the limits. Radioiodine ( 131 I) is one of the radionuclides likely to get released into the atmosphere in case of a reactor accident. During the short initial phase of release of radioactivity, 131 I is rapidly transferred to milk, leading to significant thyroid dose to those consuming milk, especially infant and children. Hence, studies on Iodine transfer through grass-cow-milk is very important. Extensive studies on transfer for 131 I through grass-cow-milk pathway after Chernobyl accident has been reported. But, under normal operational conditions of the power reactor, 131 I is not present in measurable concentration in environmental matrices of a nuclear power generating station. Stable iodine is present in all environmental samples and from the concentration of stable iodine in grass and milk, one can estimate the transfer factor. The measurement of stable iodine in environmental sample is very challenging because of its extremely low concentration. Neutron activation analysis can be used for estimation of stable iodine in the environment after suitably optimizing the condition to minimize interferences. A method has been developed based on thermal neutron activation analysis (NAA) to estimate the iodine concentration present in grass and cow milk

  13. Application of neutron activation analysis for the determination of essential elements in egg samples

    International Nuclear Information System (INIS)

    Gomes, Bruna G.; Maihara, Vera A.; Avegliano, Roseane P.

    2013-01-01

    The eggs are among the twenty foods consumed by the population of the five major regions of Brazil. Among the types of eggs, there are differences in nutritional value, which can vary according to the food of the bird. This study evaluating the elements Cl, K, Mg, Mn and Na considered essential micronutrients in food, because they are fundamental in several metabolic processes necessary for the maintenance and training of the human body. We analyzed three types of eggs: egg whites, of the quail, and the colonial in cooked and raw form, using the Instrumental Neutron Activation Analysis method (INAA). The egg samples were lyophilized and pulverized before analysis. To validate the methodology, reference materials NIST RM 8415 Whole Egg Powder and NIST SRM 1567 Wheat Flour were analyzed. The samples, reference materials and standards of the elements were irradiated for 20 seconds under a thermal neutron flux of 6,6x10 12 cm -2 s -1 in the nuclear research reactor IEA-R1 of IPEN-CNEN / SP. The results were consistent with the values of the Brazilian Table of Food Composition (TACO)

  14. Pneumatic sample-transfer system for use with the Lawrence Livermore National Laboratory rotating target neutron source (RTNS-I)

    International Nuclear Information System (INIS)

    Williams, R.E.

    1981-07-01

    A pneumatic sample-transfer system is needed to be able to rapidly retrieve samples irradiated with 14-MeV neutrons at the Rotating Target Neutron Source (RTNS-I). The rabbit system, already in place for many years, has been refurbished with modern system components controlled by an LSI-11 minicomputer. Samples can now be counted three seconds after an irradiation. There are many uses for this expanded 14-MeV neutron activation capability. Several fission products difficult to isolate from mixed fission fragments can be produced instead through (n,p) or (n,α) reactions with stable isotopes. Mass-separated samples of Nd, Mo, and Se, for example, can be irradiated to produce Pr, Nb, and As radionuclides sufficient for decay scheme studies. The system may also be used for multielement fast-neutron activation analysis because the neutron flux is greater than 2 x 10 11 n/cm 2 -sec. Single element analyses of Si and O are also possible. Finally, measurements of fast-neutron cross sections producing short-lived activation products can be performed with this system. A description of the rabbit system and instructions for its use are presented in this report

  15. Elemental analysis of water and soil environmental samples in Tabuk area by neutron capture gamma-ray spectroscopy techniques

    International Nuclear Information System (INIS)

    Al-Aseery, Sh.M.; Alamoudi, Z.; Hassan, A.M.

    2006-01-01

    The prompt and delayed gamma-rays due to neutron capture in the nuclei of the constituent elements of three soil samples and one drinking water sample have been measured. The 252 Cf and 226 Ra/Be isotopic neutron sources are used for neutron irradiation. Also, the hyper pure germanium detection system is used. The soil samples were from Astra, Tadco and El-Gammaz farms, while the water sample was taken from Tabuk city. In case of prompt gamma-ray analysis, a total of 16 elements were identified and the concentration percentage values by weight were calculated for: C, Na, Mg, Al, Si, S, Cl,, Ca, Ti, Cr, Mn, Fe, Co, Zn, Sr ad Pb elements. A comparative study between the results obtained in this work and the results obtained by ICP-MS and EDX-Ray techniques for the same samples is given

  16. Liquid-solid extraction of uranium (VI) with TOPO - molten naphthalene and determination by laser fluorimetry in geological samples

    International Nuclear Information System (INIS)

    Kumar, Sanjay; Krishnakumar, M.; Patwardhan, A.A.

    2007-01-01

    A simple, rapid, sensitive, cost-effective and efficient method for separation of uranium using tri-n-octylphosphine oxide (TOPO)-molten naphthalene as solid phase extractant and its determination by laser fluorimetry in geological samples (rock, soil, sediment) was developed. Under optimum conditions, using 50 mg TOPO and 100 mg naphthalene, 50 - 5000 ng of uranium in 10 ml sample solution (3% (v/v) HNO 3 ) could be extracted quantitatively. The extracted uranium was stripped using tetra sodium pyrophosphate (5% (v/v) solution, pH adjusted to 7.0 with H 3 PO 4 ) and determined by laser fluorimetry. The influence of different acid concentrations, the amount of solid phase extractant, sample volumes, different stripping reagents, their volumes and effect of foreign ions on the extraction and determination of uranium (VI) were investigated. Synthetic samples of varying concentration as regards uranium were prepared and analysed. Recoveries ranging from 90% to 105% were obtained. The method was validated by analyzing four certified reference materials namely, BL-5, DH-1a, SY-2, SY-3 and the values obtained for uranium agreed well with the certified values. The method was also applied to the determination of uranium in geological samples (rock, soil and sediment) by laser fluorimetry and the results obtained compared favorably with those obtained from the pellet fluorimetry method. Following the proposed method, determination limit for uranium was found to be 1 μg/g with RSD ± 10%. (author)

  17. The microwave induced plasma with optical emission spectrometry (MIP-OES) in 23 elements determination in geological samples.

    Science.gov (United States)

    Niedzielski, P; Kozak, L; Wachelka, M; Jakubowski, K; Wybieralska, J

    2015-01-01

    The article presents the optimisation, validation and application of the microwave induced plasma optical emission spectrometry (MIP-OES) dedicated for a routine determination of Ag, Al, B, Ba, Bi, Ca, Cd, Cr, Cu, Fe, Ga, In, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sr, Tl, Zn, in the geological samples. The three procedures of sample preparation has been proposed: sample digestion with the use of hydrofluoric acid for determination of total concentration of elements, extraction by aqua regia for determination of the quasi-total element concentration and extraction by hydrochloric acid solution to determine contents of the elements in acid leachable fraction. The detection limits were on the level 0.001-0.121 mg L(-1) (from 0.010-0.10 to 1.2-12 mg kg(-1) depend on the samples preparation procedure); the precision: 0.20-1.37%; accuracy 85-115% (for recovery for certified standards materials analysis and parallel analysis by independent analytical techniques: X-ray fluorescence (XRF) and flame absorption spectrometry (FAAS)). The conformity of the results obtained by MIP-OES analytical procedures with the results obtained by XRF and FAAS analysis allows to propose the procedures for studies of elemental composition of the fraction of the geological samples. Additionally, the MIP-OES technique is much less expensive than ICP techniques and much less time-consuming than AAS techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Elemental analysis and plant samples at el-Manzala lake by neutron activation analysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Eissa, E A; Rofail, N B; Abdel-Haleem, A S; El-Abbady, W H; Hassan, A M [Arab Republic of Egypt, Atomic energy Authority, Reactor and Neutron Physiscs Department, Cairo (Egypt)

    1996-12-31

    A soil and a plant samples were taken from two locations, Bahr el-Bakar and Bahr Kados at the Manzala lake, where a high pollution is expected. The samples were especially treated and prepared for investigation by thermal neutron activation analysis (NAA). The irradiation facilities of the first egyptian research reactor (ET-R R-1) and the hyper pure germanium (HPGe) detection system were used for such a type of analysis. Among the 34 identified elements Fe, Co, As, Ru, Cd, Te, La, Sm, Eu, Tb, Hg, Th, and U are of a special significance because of their toxic deleterious impact to organisms. This work is a part of a research project concerning pollution studies on the river nile and some lakes of egypt. The data obtained in the present work stand as a reference basic record for any future follow up of the contamination level. 1 tab.

  19. Trace determination of uranium and thorium in biological samples by radiochemical neutron activation analysis

    International Nuclear Information System (INIS)

    Benedik, Ljudmila; Repinc, Urska; Byrne, Anthony R.; Stegnar, Peter

    2002-01-01

    Radiochemical neutron activation analysis (RNAA) is an excellent method for determining uranium and thorium; it offers unique possibilities for their ultratrace analysis using selective radiochemical separations. Regarding the favourably sensitive nuclear characteristics of uranium and of thorium with respect to RNAA, but the different half-lives of their induced nuclides, two different approaches were used. In the first approach uranium and thorium were determined separately via 239 U, 239 Np and 233 Pa. In the second approach these elements were 239 239 233 determined simultaneously in a single sample using U and/or Np and Pa. Isolation of induced nuclides was based on separation by extraction and/or anion exchange chromatography. Chemical yields were measured in each sample aliquot using added 235 U, 238 Np and 231 Pa radioisotopic tracers. (author)

  20. Investigation of Hg volatile losses from samples and standards during neutron activation analysis

    International Nuclear Information System (INIS)

    Dubinskaya, N.; Dundua, V.; Chikhladze, N.

    1979-01-01

    The losses of Hg from phenol formaldehyde resin - bound standards and hair samples in neutron activation analysis in case of their irradiation in the water filled nuclear reactor channel is studied. The mean losses of Hg during 20-30 hrs irradiation at (2-3)x10 18 n/cm 2 are 15-20% with their stopping at double Al-covers. The mean losses of Hg from standards at 200, 250 and 300 deg C are 30, 61 and 86% respectively and do not occur at 150 deg C after their 5 hour heating. The losses of Hg from hair samples packed in polyethylene tubes through the package walls in experimental conditions are not observed

  1. Elemental analysis and plant samples at el-Manzala lake by neutron activation analysis technique

    International Nuclear Information System (INIS)

    Eissa, E.A.; Rofail, N.B.; Abdel-Haleem, A.S.; El-Abbady, W.H.; Hassan, A.M.

    1995-01-01

    A soil and a plant samples were taken from two locations, Bahr el-Bakar and Bahr Kados at the Manzala lake, where a high pollution is expected. The samples were especially treated and prepared for investigation by thermal neutron activation analysis (NAA). The irradiation facilities of the first egyptian research reactor (ET-R R-1) and the hyper pure germanium (HPGe) detection system were used for such a type of analysis. Among the 34 identified elements Fe, Co, As, Ru, Cd, Te, La, Sm, Eu, Tb, Hg, Th, and U are of a special significance because of their toxic deleterious impact to organisms. This work is a part of a research project concerning pollution studies on the river nile and some lakes of egypt. The data obtained in the present work stand as a reference basic record for any future follow up of the contamination level. 1 tab

  2. Sample positioning in neutron diffraction experiments using a multi-material fiducial marker

    Energy Technology Data Exchange (ETDEWEB)

    Marais, D., E-mail: Deon.Marais@necsa.co.za [Research and Development Division, South African Nuclear Energy Corporation (Necsa) SOC Limited, PO Box 582, Pretoria 0001 (South Africa); School of Mechanical and Nuclear Engineering, North-West University, Potchefstroom 2520 (South Africa); Venter, A.M., E-mail: Andrew.Venter@necsa.co.za [Research and Development Division, South African Nuclear Energy Corporation (Necsa) SOC Limited, PO Box 582, Pretoria 0001 (South Africa); Faculty of Agriculture Science and Technology, North-West University, Mahikeng 2790 (South Africa); Markgraaff, J., E-mail: Johan.Markgraaff@nwu.ac.za [School of Mechanical and Nuclear Engineering, North-West University, Potchefstroom 2520 (South Africa); James, J., E-mail: Jon.James@open.ac.uk [Faculty of Mathematics, Computing and Technology, The Open University, Milton Keynes, MK76AA England (United Kingdom)

    2017-01-01

    An alternative sample positioning method is reported for use in conjunction with sample positioning and experiment planning software systems deployed on some neutron diffraction strain scanners. In this approach, the spherical fiducial markers and location trackers used with optical metrology hardware are replaced with a specifically designed multi-material fiducial marker that requires one diffraction measurement. In a blind setting, the marker position can be determined within an accuracy of ±164 µm with respect to the instrument gauge volume. The scheme is based on a pre-determined relationship that links the diffracted peak intensity to the absolute positioning of the fiducial marker with respect to the instrument gauge volume. Two methods for establishing the linking relationship are presented, respectively based on fitting multi-dimensional quadratic functions and a cross-correlation artificial neural network.

  3. Determination of Mineral Contents in Unpolished Rice and Bean Samples by Neutron Activation Analysis

    International Nuclear Information System (INIS)

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

    2012-01-01

    As scientists have focused their researches on the health impacts caused by mineral nutrient deficiencies and hazardous elements, public concern regarding mineral intake from dietary food is rising. In this reason, the dietary habits of Koreans have been shifted from white rice to more nutrient rice like unpolished rice and rice mixed with beans. It is known that unpolished rice and beans contain more protein, vitamin and mineral contents than white rice and are more beneficial to human health, even though they sometimes cause indigestion or allergy. The objectives of this study were to determine the mineral contents in unpolished rice and bean samples by a neutron activation analysis (NAA) and to compare the level of mineral contents between the samples

  4. Project and construction of a pneumatic system for the transference of samples to a neutron generator

    International Nuclear Information System (INIS)

    Carvalho, A.N. de

    1983-01-01

    A prototype of a system for the transport of irradiated samples to and from a neutron generator, was constructed, using compressed air as propeller agent. Compressed air was injected through electrically driven values. The sample, transported by the pressure wave, was inserted into a PVC tube 50m long and weighing 23.0 g. The first tests were carried out in order to determine the times needed to transport the above-mentioned PVC support along a PVC tube of 3m length and 3/4 diameter for different air pressures applied; it was verified that for pressures between 3.0 and 8.0 kgf/cm 2 , transport times were always smaller than 2 seconds. These results showed the viability of constructing a definitive system, already projected. (C.L.B.) [pt

  5. Collection of size fractionated particulate matter sample for neutron activation analysis in Japan

    International Nuclear Information System (INIS)

    Otoshi, Tsunehiko; Nakamatsu, Hiroaki; Oura, Yasuji; Ebihara, Mitsuru

    2004-01-01

    According to the decision of the 2001 Workshop on Utilization of Research Reactor (Neutron Activation Analysis (NAA) Section), size fractionated particulate matter collection for NAA was started from 2002 at two sites in Japan. The two monitoring sites, ''Tokyo'' and ''Sakata'', were classified into ''urban'' and ''rural''. In each site, two size fractions, namely PM 2-10 '' and PM 2 '' particles (aerodynamic particle size between 2 to 10 micrometer and less than 2 micrometer, respectively) were collected every month on polycarbonate membrane filters. Average concentrations of PM 10 (sum of PM 2-10 and PM 2 samples) during the common sampling period of August to November 2002 in each site were 0.031mg/m 3 in Tokyo, and 0.022mg/m 3 in Sakata. (author)

  6. Neutron activation analysis of neonate and maternal hair sampled in areas with different levels of pollution

    International Nuclear Information System (INIS)

    Obrusnik, I.; Skrivanek, O.; Umlaufova, M.; Hovorka, V.

    1985-01-01

    Instrumental neutron activation analysis was performed on human head hair of newborns and mothers sampled in two areas with different levels of environmental exposure. The group of neonates from the exposed area (polluted by thermal power plants burning brown coal and by chemical industry) exhibited higher levels of several trace elements in hair, e.g. Se, Zn, Hg and Sb in comparison with the control group. Moreover, the mean concentrations of Se, Hg, Zn and Br in neonate hair were found to be higher than in mothers' hair. Although the study revealed statistically significant differences in the composition of neonate hair samples in areas with different levels of environmental exposure, the differences are relatively small. Only a thorough long-term study both with environmental and medical observations can prove a direct connection of the elevated levels of some trace elements in neonate hair with the higher incidence of mental diseaes of children living in the exposed area. (author)

  7. Determination of Mineral Contents in Unpolished Rice and Bean Samples by Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Moon, J. H.; Kim, S. H.; Baek, S. Y.; Chung, Y. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    As scientists have focused their researches on the health impacts caused by mineral nutrient deficiencies and hazardous elements, public concern regarding mineral intake from dietary food is rising. In this reason, the dietary habits of Koreans have been shifted from white rice to more nutrient rice like unpolished rice and rice mixed with beans. It is known that unpolished rice and beans contain more protein, vitamin and mineral contents than white rice and are more beneficial to human health, even though they sometimes cause indigestion or allergy. The objectives of this study were to determine the mineral contents in unpolished rice and bean samples by a neutron activation analysis (NAA) and to compare the level of mineral contents between the samples

  8. Determination of traces of lithium in biological, environmental and metal samples by neutron activation analysis

    International Nuclear Information System (INIS)

    Yang, J.Y.; Tseng, C.L.; Lo, J.M.; Yang, M.H.

    1985-01-01

    Lithium in environmental, biological and metal samples was determined by neutron activation analysis via the 6 Li(n,α)T and 16 O(T,n) 18 F reactions. The samples were converted to aqueous solutions either by dissolution or by digestion and their aliquots were irradiated in a nuclear reactor for 2 h. The irradiated sample solution, was placed in a ZrO 2 column on which the 18 F nuclide was adsorbed. Most of the coexisting nuclides 24 Na, 82 Br, 38 Cl, 64 Cu, etc. were separated by elution with pH 1proportional3 solution. The column was subjected to a Ge(Li) detector for γ-ray spectrometry. The lithium content in the sample was estimated from the 18 F activity obtained. The matrix effect can be eliminated by either strong dilution of the samples in aqueous medium or by the method of standard addition. Lithium can be determined with high precision and accuracy in sub-ppm samples. (orig.) [de

  9. Trace elements detection in whole food samples by Neutron Activation Analysis, k0-method

    International Nuclear Information System (INIS)

    Sathler, Márcia Maia; Menezes, Maria Ângela de Barros Correia; Salles, Paula Maria Borges de

    2017-01-01

    Inorganic elements, from natural and anthropogenic sources are present in foods in different concentrations. With the increase in anthropogenic activities, there was also a considerable increase in the emission of these elements in the environment, leading to the need of monitoring the elemental composition of foods available for consumption. Numerous techniques have been used to detect inorganic elements in biological and environmental matrices, always aiming at reaching lower detection limits in order to evaluate the trace element content in the sample. Neutron activation analysis (INAA), applying the k 0 -method, produces accurate and precise results without the need of chemical preparation of the samples – that could cause their contamination. This study evaluated the presence of inorganic elements in whole foods samples, mainly elements on trace levels. For this purpose, seven samples of different types of whole foods were irradiated in the TRIGA MARK I IPR-R1 research reactor - located at CDTN/CNEN, in Belo Horizonte, MG. It was possible to detect twenty two elements above the limit of detection in, at least, one of the samples analyzed. This study reaffirms the INAA, k 0 - method, as a safe and efficient technique for detecting trace elements in food samples. (author)

  10. Internal Stress Distribution Measurement of TIG Welded SUS304 Samples Using Neutron Diffraction Technique

    Science.gov (United States)

    Muslih, M. Refai; Sumirat, I.; Sairun; Purwanta

    2008-03-01

    The distribution of residual stress of SUS304 samples that were undergone TIG welding process with four different electric currents has been measured. The welding has been done in the middle part of the samples that was previously grooved by milling machine. Before they were welded the samples were annealed at 650 degree Celsius for one hour. The annealing process was done to eliminate residual stress generated by grooving process so that the residual stress within the samples was merely produced from welding process. The calculation of distribution of residual stress was carried out by measuring the strains within crystal planes of Fe(220) SUS304. Strain, Young modulus, and Poisson ratio of Fe(220) SUS304 were measured using DN1-M neutron diffractometer. Young modulus and Poisson ratio of Fe(220) SUS304 sample were measured in-situ. The result of calculations showed that distribution of residual stress of SUS304 in the vicinity of welded area is influenced both by treatments given at the samples-making process and by the electric current used during welding process.

  11. Trace elements detection in whole food samples by Neutron Activation Analysis, k{sub 0}-method

    Energy Technology Data Exchange (ETDEWEB)

    Sathler, Márcia Maia; Menezes, Maria Ângela de Barros Correia, E-mail: maia.sathler@gmail.com, E-mail: menezes@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Salles, Paula Maria Borges de, E-mail: pauladesalles@yahoo.com.br [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2017-07-01

    Inorganic elements, from natural and anthropogenic sources are present in foods in different concentrations. With the increase in anthropogenic activities, there was also a considerable increase in the emission of these elements in the environment, leading to the need of monitoring the elemental composition of foods available for consumption. Numerous techniques have been used to detect inorganic elements in biological and environmental matrices, always aiming at reaching lower detection limits in order to evaluate the trace element content in the sample. Neutron activation analysis (INAA), applying the k{sub 0}-method, produces accurate and precise results without the need of chemical preparation of the samples – that could cause their contamination. This study evaluated the presence of inorganic elements in whole foods samples, mainly elements on trace levels. For this purpose, seven samples of different types of whole foods were irradiated in the TRIGA MARK I IPR-R1 research reactor - located at CDTN/CNEN, in Belo Horizonte, MG. It was possible to detect twenty two elements above the limit of detection in, at least, one of the samples analyzed. This study reaffirms the INAA, k{sub 0} - method, as a safe and efficient technique for detecting trace elements in food samples. (author)

  12. Activation analysis of rare-earth elements in opium and cannabis samples. [Neutron reactions

    Energy Technology Data Exchange (ETDEWEB)

    Henke, G [Muenster Univ. (Germany, F.R.). Inst. fuer Pharmazeutische Chemie

    1977-01-01

    Rare-earth concentrations in 65 Opium, Cannabis and Cannabis resin samples seized from various parts of the world were determined by destructive NAA. Because of the greater concentrations of Ca, P, K, Fe, Na and Si in plant materials, rare-earth elements were isolated after neutron irradiation and determined by gamma-spectrometry. The main steps of the method are: Preashing of 1 g Cannabis resin, 2.5 g Cannabis, or 7.5 g Opium, respectively, in quartz ampoules (5 h, 500 deg C). Neutron irradiation, 24 h at 5x10/sup 13/n cm/sup -2/sec/sup -1/. Cooling period 2-3 days. After addition of 0.1 ..mu..Ci /sup 139/Ce and rare-earth carriers wet ashing of irradiated samples with H/sub 2/SO/sub 4//HNO/sub 3/, followed by alternate addition of HNO/sub 3/ and H/sub 2/O/sub 2/ (30%). Precipitation and removal of silicates, precipitation of fluorides, precipitation of hydroxides. Dissolution of hydroxides in HCl. Extraction with di-(2-ethylhexyl)phosphate (DEHP)/toluene and twice back-extraction of rare earths, gamma-spectrometry of HCl phase. Due to sample activity and half-life of nuclides, three measurements were made on each sample: 2 days (for La, Sm, Gd, Ho, Er, Yb); 14 days (for Nd, Lu) and 30 days after irradiation (for Ce, Eu, Tb). Great variations in absolute element concentrations, but only small significant differences of rare earth concentration ratios were found, indicating inconsiderable biogeochemical fractionation. The mean values of these ratios correspond to the relative abundances of the rare earths in the upper continental earth's crust.

  13. A study on aluminum determination in environmental samples by Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Noyori, Amanda

    2017-01-01

    Aluminum determinations are of great interest since this element is toxic to humans and it is widely distributed in the environment. Besides, the determinations of this element by conventional analytical methods present difficulties due to sample contamination during the analyses. Neutron activation analysis (NAA) for Al determination presents advantages of fast analyses and of high sensitivity. However, NAA of Al does present problems of P and Si nuclear reaction interferences. Aluminum is determined by measuring 28 Al, formed in the reaction 27 Al (n, γ) 28 Al, the same radioisotope formed in reactions 31 P (n, α) 28 Al and 28 Si (n, p) 28 Al. The purpose of this study was to determine Al in environmental samples by NAA correcting these interferences using correction factors, and determining P and Si concentrations in the samples. In this study, certified reference materials and biomonitor samples (tree barks and lichen) were analyzed. Experimental procedure consisted of irradiating an aliquot of the sample at the IEA-R1 nuclear research reactor together with Al standard, followed by gamma ray spectrometry. Phosphorus was determined by measuring beta radiation of 32 P using a Geiger-Müller counter. Silicon was determined by epithermal neutron activation analysis and measuring 29 Al formed in the reaction 29 Si (n, p) 29 Al. Results obtained in the determination of Al, P and Si in the certified reference materials showed good precision and accuracy with |Z-score| ≤ 2. Aluminum results in the biomonitor samples varied from to 253 to 15783 μg g -1 . In the case of P its concentrations varied from 283 to 1946 μg g -1 . Silicon determinations in biomonitors varied from 0.11 to 7.8 %. The interference contribution rates in the analyses of the biomonitor samples were of the order of 2.0 % and this contribution depends on the relation between concentrations of interfering elements and of Al in the sample. Detection limit values of Al in the biomonitor analyses

  14. Reactivity and neutron emission measurements of burnt PWR fuel rod samples in LWR-PROTEUS phase II

    International Nuclear Information System (INIS)

    Murphy, M. F.; Jatuff, F.; Grimm, P.; Seiler, R.; Brogli, R.; Meier, G.; Berger, H. D.; Chawla, R.

    2004-01-01

    Measurements have been made of the reactivity effects and the neutron emission rates of uranium oxide and mixed oxide burnt fuel samples having a wide range of burnup values and coming from a Pressurised Water Reactor (PWR). The reactivity measurements have been made in a PWR lattice moderated in turn with: water, a water and heavy water mixture, and water containing boron. An interesting relationship has been found between the neutron emission rate and the measured reactivity. (authors)

  15. Developing a Relationship Between LIBS Ablation and Pit Volume for In Situ Dating of Geologic Samples

    Science.gov (United States)

    Devismes, D.; Cohen, B. A.; Gillot, P.-Y.

    2015-01-01

    In planetary exploration, in situ absolute geochronology is an important measurement. Thus far, on Mars, the age of the surface has largely been determined by crater density counting, which gives relative ages. These ages can have significant uncertainty as they depend on many poorly constrained parameters. More than that, the curves must be tied to absolute ages to relate geologic timescales on Mars to the rest of the solar system. Thus far, only the lost lander Beagle 2 was designed to conduct absolute geochronology measurements, though some recent attempts using MSL Curiosity show that this investigation is feasible (Reference Farley here) and should be strongly encouraged for future flight.

  16. Fourier descriptors analysis of anisotropy and preferred Orientation in geological samples

    International Nuclear Information System (INIS)

    Santiago Buey, C. de

    2011-01-01

    This study focuses on the use of Fourier descriptors to evaluate and quantify two specific fabric characteristics of geological materials: anisotropy of particles or voids morphologies and particle orientation. To this end, a theoretical section of a rock was created, made of ellipses and rectangles of different axes ratios and different orientations. The Fourier descriptors method was applied to calculate the anisotropy and orientation of each particle and, finally, a rose diagram was constructed to represent the particles orientations distribution and to observe the presence or not of any preferred orientation. (Author) 15 refs.

  17. Study on the determination of palladium in biological samples by the method of neutron activation analysis

    International Nuclear Information System (INIS)

    Cavalcante, Cassio Queiroz

    2007-01-01

    Palladium is one of platinum group elements present in the nature at very low concentrations. However with the use of this element in the automobile catalyzers Pd became a new pollutant. Besides, Pd has been studied in the preparation of new antitumour drugs. Consequently, there is a need to determine Pd concentrations in biological and environmental samples. This study presents palladium results obtained in the analysis of biological samples and reference materials using instrumental thermal and epithermal neutron activation analysis (INAA and ENAA). The solvent extraction and solid phase extraction separation methods were also applied before ENAA. The samples analyzed in this study were, reference material BCR 723 - Palladium, Platinum and Rhodium in road dust, CCQM-P63 automotive catalyst material of the Proficiency Test and bovine tissue samples containing palladium prepared in the laboratory. Samples and palladium synthetic standard were irradiated at the IEA-R1 nuclear research reactor under thermal neutron flux of about 4 x 10 12 n cm-2 s-1, during a period of 4 and 16 h for INAA and ENAA, respectively. The induced gamma activity of 109 Pd to the sample and standard was measured using a hyper pure Ge detector coupled to a gamma ray spectrometer. The palladium concentration was calculated by comparative method. The gamma ray energy of 109 Pd radioisotope measured was of 88.0 keV, located in a spectrum region of low energy where occurs the interference of X rays, 'Bremsstrahlung' radiations, as well as Compton effect of 24 Na. The pre-separation of palladium from interfering elements by solvent extraction was performed using dimethylglyoxime complexant and chloroform as diluent. In the case of the pre separation procedure using solid reversed phase column, the palladium was retained using N,N-diethyl-N'-benzoyl thiourea complexant and eluted using ethanol. Aliquots of the resulting solutions from the pre-separations, free of interfering elements, were

  18. Application of neutron activation analysis to trace element determinations in lung samples

    International Nuclear Information System (INIS)

    Rocero, Sizue Ota

    1992-01-01

    The purpose of this work was to apply the instrumental neutron activation analysis method to determine trace elements in lung samples from smokers and non smokers. Samples of lung tissues and lymph nodes from pulmonary hilum analyzed were collected from autopsies by researchers from the Medicine College of the University of Sao Paulo, SP, Brazil. Adequate conditions for preparation and analysis of samples were previously established. The preparation of samples consisted of homogenization, lyophilization and sterilization in 60 Co source. The samples and standards were irradiated in the IEA-R1 reactor under thermal neutron flux of 3.7 x 10 11 n.cm -2 .s -1 for 30 min to determine Cl, K, Mn and Na and for 16 h under flux of 10 19 n.cm -2 .s -1 for the determination of Au, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Rb, Sb, Sc, Se, Th and Zn. The counting were carried out with a hiperpure (ge) detector connected to a 4096 channels analyzer and a microcomputer. the results obtained for lung sample analyses indicated a good reproducibility of the method for most of the elements determined with relative standard deviations lower than 10.5%. The accuracy of the method was evaluated by analyzing reference materials such as IAEA Animal Muscle H-4, NIST Bovine Liver 1577a, IUPAC Bowen's Kale and NIES Vehicle Exhaust Particulates. The results obtained from these analyzes agreed with the values of the literature for several elements with relative errors less than 20%. Less precise and accurate results were obtained for elements with concentrations at the Mup/Kg levels. Elemental concentrations obtained in the lung tissue analyses were within the range of reference values for normal subjects presented in the literature, except for the Cl concentrations for non smokers, Hf in both groups and Sb for the smokers. By comparing results obtained for lung samples from smokers and non smokers, the concentrations of Ce, Cr and Sb were higher in lungs from smokers and the others elements were

  19. Determination of silver, gold, zinc and copper in mineral samples by various techniques of instrumental neutron activation analysis; Determinacion de plata, oro, zinc y cobre en muestras minerales mediante diversas tecnicas de analisis por activacion de neutrones instrumental

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez R, N. I.; Rios M, C.; Pinedo V, J. L. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Yoho, M.; Landsberger, S., E-mail: neisla126@hotmail.com [University of Texas at Austin, Nuclear Engineering Teaching Laboratory, Austin 78712, Texas (United States)

    2015-09-15

    Using the method of instrumental neutron activation analysis, mineral exploration samples were analyzed in order to determine the concentrations of silver, gold, zinc and copper; these minerals being the main products of benefit of Tizapa and Cozamin mines. Samples were subjected to various techniques, where the type of radiation and counting methods were chosen based on the specific isotopic characteristics of each element. For calibration and determination of concentrations the comparator method was used, certified standards were subjected to the same conditions of irradiation and measurement that the prospecting samples. The irradiations were performed at the research reactor TRIGA Mark II of the University of Texas at Austin. The silver concentrations were determined by Cyclical Epithermal Neutron Activation Analysis. This method in combination with the transfer pneumatic system allowed a good analytical precision and accuracy in prospecting for silver, from photo peak measurement 657.7 keV of short half-life radionuclide {sup 110}Ag. For the determination of gold and zinc, Epithermal Neutron Activation Analysis was used, the photo peaks analyzed corresponded to the energies 411.8 keV of radionuclide {sup 199}Au and 438.6 keV of metastable radionuclide {sup 69m}Zn. On the other hand, copper quantification was based on the photo peak analysis of 1039.2 keV produced by the short half-life radionuclide {sup 66}Cu, by Thermal Neutron Activation Analysis. The photo peaks measurement corresponding to gold, zinc and copper was performed using a Compton suppression system, which allowed an improvement in the signal to noise relationship, so that better detection limits and low uncertainties associated with the results were obtained. Comparing elemental concentrations the highest values in silver, zinc and copper was for samples of mine Tizapa. Regarding gold values were found in the same range for both mines. To evaluate the precision and accuracy of the methods used

  20. Split Hopkinson Resonant Bar Test for Sonic-Frequency Acoustic Velocity and Attenuation Measurements of Small, Isotropic Geologic Samples

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, S.

    2011-04-01

    Mechanical properties (seismic velocities and attenuation) of geological materials are often frequency dependent, which necessitates measurements of the properties at frequencies relevant to a problem at hand. Conventional acoustic resonant bar tests allow measuring seismic properties of rocks and sediments at sonic frequencies (several kilohertz) that are close to the frequencies employed for geophysical exploration of oil and gas resources. However, the tests require a long, slender sample, which is often difficult to obtain from the deep subsurface or from weak and fractured geological formations. In this paper, an alternative measurement technique to conventional resonant bar tests is presented. This technique uses only a small, jacketed rock or sediment core sample mediating a pair of long, metal extension bars with attached seismic source and receiver - the same geometry as the split Hopkinson pressure bar test for large-strain, dynamic impact experiments. Because of the length and mass added to the sample, the resonance frequency of the entire system can be lowered significantly, compared to the sample alone. The experiment can be conducted under elevated confining pressures up to tens of MPa and temperatures above 100 C, and concurrently with x-ray CT imaging. The described Split Hopkinson Resonant Bar (SHRB) test is applied in two steps. First, extension and torsion-mode resonance frequencies and attenuation of the entire system are measured. Next, numerical inversions for the complex Young's and shear moduli of the sample are performed. One particularly important step is the correction of the inverted Young's moduli for the effect of sample-rod interfaces. Examples of the application are given for homogeneous, isotropic polymer samples and a natural rock sample.

  1. Determination of the hydrogen content of oil samples from Nigeria using an Am-Be neutron source

    International Nuclear Information System (INIS)

    Jonah, S.A.; Elegba, S.B.; Zakari, I.I.

    1998-01-01

    A 5 Ci Am-Be neutron source-based facility, which utilises the principles of thermal neutron reflection technique in combination with foil activation method, has been used to determine the total hydrogen content of commercial oil samples from Nigeria. With an established detection limit of 0.25 H w% for oil matrix of volume 600-ml, the total hydrogen contents of the samples were found to be in the range of 11.11-14.22 H w%. The facility is economical and suitable for the determination of moisture in solid samples. A brief description of the ongoing projects and future plans concerning the CRP are enumerated. (author)

  2. Major and trace elements assessment in sediment samples from Rio Grande Reservoir, by neutron activation analysis

    International Nuclear Information System (INIS)

    Franklin, Robson L.; Ferreira, Francisco J.; Favaro, Deborah I.T.; Bevilacqua, Jose Eduardo

    2009-01-01

    The Rio Grande Reservoir, Southeast of the Sao Paulo Metropolitan Area (SPMA) supplies water for four counties (Sao Bernardo do Campo, Sao Caetano do Sul, Santo Andre and Diadema). It has been seriously affected by urban expansion, due to chaotic urban occupation and improper use of the surrounding areas. In this study bottom sediment samples were collected, by using a Van Veen sampler, during the dry and rainy seasons. Four sampling points were defined by using GPS and are located at the mouth of the Rio Grande and Ribeirao Pires Rivers, in the middle of the reservoir and near the catchment point of the water supply. The sediment samples were submitted to instrumental neutron activation analysis (INAA) and the following elements were determined: As, Ba, Br, Co, Cr, Cs, Rb, Sb, Sc, Se, Ta, Th, U e Zn and the rare earth elements Ce, Eu, La, Lu, Nd, Sm, Tb, Yb. Short irradiation was also performed for total Hg determination by NAA using 197 Hg radioisotope. This was possible due to the high Hg concentration levels in these sediments. The methodology validation was carried out by certified reference material analyses. The results obtained for multielemental concentrations in the sediment samples were compared to NASC (North American Shale Composite) values. The concentration values obtained for As and metals Cr, Hg and Zn in the sediment samples were compared to the Canadian Council of Minister of the Environment (CCME) oriented values (TEL and PEL values) and adopted by CETESB. (author)

  3. Determination of trace elements in fisheries samples by instrumental neutron and photon activation analysis

    International Nuclear Information System (INIS)

    Chattopadhyay, A.; Ellis, K.M.; Nimalasiri Desilva, K.

    1979-01-01

    An instrumental neutron activation analysis (INAA) method has been developed for the simultaneous determination of trace concentrations of up to 23 elements in fisheries samples. The INAA method consists of irradiations of wet and lyophilized cod muscle and liver samples for three different periods at a flux density of 5x10 11 n.cm -2 .s -1 and subsequent measurements after four different decay periods using high-resolution Ge(Li) gamma-ray spectrometry. Concentrations of several essential and toxic elements have been determined. Loss of certain elements during lyophilization has been studied. Elemental distribution in muscles and livers as a function of the age of fish has been investigated. Precision and accuracy of the INAA method have been evaluated by analysing replicate samples, National Bureau of Standards' bovine liver standard reference material, and an intercalibration fish flour sample provided by the International Council for the Exploration of the Sea. A few fish samples have also been analysed by an alternative method, namely instrumental photon activation analysis (IPAA). Elemental concentrations determined by both INAA and IPAA methods are reported here. (author)

  4. Determination of molybdenum and selenium in bioenvironmental samples using neutron activation analysis

    International Nuclear Information System (INIS)

    Abu-Samra, A.; Morris, J.S.; Koirtyohann, S.R.; Vogt, J.R.

    1974-01-01

    Because of the increasing interest as to their roles in biological systems, a procedure has been developed by which molybdenum and selenium can be determined at nanogram levels in these types of samples. Results from the analysis of orchard leaves and bovine liver are presented. The samples are packaged in pre-cleaned quartz vials prepared from GE-204 tubing. If both selenium and molybdenum are to be determined, the samples are irradiated for 40 or more hours at a thermal neutron flux of 8 x 10 13 n cm -2 sec -1 . After the samples have decayed for approximately 48 hours the vials are unpackaged, cleaned in aqua-regia, and broken. The irradiation period can be reduced to 24 hours if molybdenum is to be determined individually or if the selenium content is known to be 1 microgram or more. The sample is digested with carriers and the selenium is then distilled as a volatile selenium halide. Elemental selenium is precipitated by reduction with SO 2 produced through the protonation of the hydrogen sulfite ion and subsequent decomposition of the resulting sulfurous acid. The 401 keV summation peak of 75 Se is normally used for quantitative determination. The chemical yield is determined by drying and weighing the elemental selenium

  5. Design and Demonstration of a Material-Plasma Exposure Target Station for Neutron Irradiated Samples

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Juergen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Aaron, A. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bell, Gary L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burgess, Thomas W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ellis, Ronald James [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giuliano, D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Howard, R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kiggans, James O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lessard, Timothy L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ohriner, Evan Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Perkins, Dale E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Varma, Venugopal Koikal [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-10-20

    -state heat fluxes of 5–20 MW/m2 and ion fluxes up to 1024 m-2s-1. Since PFCs will have to withstand neutron irradiation displacement damage up to 50 dpa, the target station design must accommodate radioactive specimens (materials to be irradiated in HFIR or at SNS) to enable investigations of the impact of neutron damage on materials. Therefore, the system will have to be able to install and extract irradiated specimens using equipment and methods to avoid sample modification, control contamination, and minimize worker dose. Included in the design considerations will be an assessment of all the steps between neutron irradiation and post-exposure materials examination/characterization, as well as an evaluation of the facility hazard categorization. In particular, the factors associated with the acquisition of radioactive specimens and their preparation, transportation, experimental configuration at the plasma-specimen interface, post-plasma-exposure sample handling, and specimen preparation will be evaluated. Neutronics calculations to determine the dose rates of the samples were carried out for a large number of potential plasma-facing materials.

  6. Design and Demonstration of a Material-Plasma Exposure Target Station for Neutron Irradiated Samples

    International Nuclear Information System (INIS)

    Rapp, Juergen; Aaron, A. M.; Bell, Gary L.; Burgess, Thomas W.; Ellis, Ronald James; Giuliano, D.; Howard, R.; Kiggans, James O.; Lessard, Timothy L.; Ohriner, Evan Keith; Perkins, Dale E.; Varma, Venugopal Koikal

    2015-01-01

    5-20 MW/m"2 and ion fluxes up to 10"2"4 m"-"2s"-"1. Since PFCs will have to withstand neutron irradiation displacement damage up to 50 dpa, the target station design must accommodate radioactive specimens (materials to be irradiated in HFIR or at SNS) to enable investigations of the impact of neutron damage on materials. Therefore, the system will have to be able to install and extract irradiated specimens using equipment and methods to avoid sample modification, control contamination, and minimize worker dose. Included in the design considerations will be an assessment of all the steps between neutron irradiation and post-exposure materials examination/characterization, as well as an evaluation of the facility hazard categorization. In particular, the factors associated with the acquisition of radioactive specimens and their preparation, transportation, experimental configuration at the plasma-specimen interface, post-plasma-exposure sample handling, and specimen preparation will be evaluated. Neutronics calculations to determine the dose rates of the samples were carried out for a large number of potential plasma-facing materials.

  7. Methods for preparing comparative standards and field samples for neutron activation analysis of soil

    International Nuclear Information System (INIS)

    Glasgow, D.C.; Dyer, F.F.; Robinson, L.

    1994-01-01

    One of the more difficult problems associated with comparative neutron activation analysis (CNAA) is the preparation of standards which are tailor-made to the desired irradiation and counting conditions. Frequently, there simply is not a suitable standard available commercially, or the resulting gamma spectrum is convoluted with interferences. In a recent soil analysis project, the need arose for standards which contained about 35 elements. In response, a computer spreadsheet was developed to calculate the appropriate amount of each element so that the resulting gamma spectrum is relatively free of interferences. Incorporated in the program are options for calculating all of the irradiation and counting parameters including activity produced, necessary flux/bombardment time, counting time, and appropriate source-to-detector distance. The result is multi-element standards for CNAA which have optimal concentrations. The program retains ease of use without sacrificing capability. In addition to optimized standard production, a novel soil homogenization technique was developed which is a low cost, highly efficient alternative to commercially available homogenization systems. Comparative neutron activation analysis for large scale projects has been made easier through these advancements. This paper contains details of the design and function of the NAA spreadsheet and innovative sample handling techniques

  8. Methods for preparing comparative standards and field samples for neutron activation analysis of soil

    International Nuclear Information System (INIS)

    Glasgow, D.C.; Dyer, F.F.; Robinson, L.

    1995-01-01

    One of the more difficult problems associated with comparative neutron activation analysis (CNAA) is the preparation of standards which are tailor-made to the desired irradiation and counting conditions. Frequently, there simply is not a suitable standard available commercially, or the resulting gamma spectrum is convoluted with interferences. In a recent soil analysis project, the need arose for standards which contained about 35 elements. In response, a computer spreadsheet was developed to calculate the appropriate amount of each element so that the resulting gamma spectrum is relatively free of interferences. Incorporated in the program are options for calculating all of the irradiation and counting parameters including activity produced, necessary flux/bombardment time, counting time, and appropriate source-to-detector distance. The result is multi-element standards for CNAA which have optimal concentrations. The program retains ease of use without sacrificing capability. In addition to optimized standard production, a novel soil homogenization technique was developed which is a low cost, highly efficient alternative to commercially available homogenization systems. Comparative neutron activation analysis for large scale projects has been made easier through these advancements. This paper contains details of the design and function of the NAA spreadsheet and innovative sample handling techniques. (author) 7 refs.; 5 tabs

  9. Monte Carlo Calculation of Thermal Neutron Inelastic Scattering Cross Section Uncertainties by Sampling Perturbed Phonon Spectra

    Science.gov (United States)

    Holmes, Jesse Curtis

    established that depends on uncertainties in the physics models and methodology employed to produce the DOS. Through Monte Carlo sampling of perturbations from the reference phonon spectrum, an S(alpha, beta) covariance matrix may be generated. In this work, density functional theory and lattice dynamics in the harmonic approximation are used to calculate the phonon DOS for hexagonal crystalline graphite. This form of graphite is used as an example material for the purpose of demonstrating procedures for analyzing, calculating and processing thermal neutron inelastic scattering uncertainty information. Several sources of uncertainty in thermal neutron inelastic scattering calculations are examined, including sources which cannot be directly characterized through a description of the phonon DOS uncertainty, and their impacts are evaluated. Covariances for hexagonal crystalline graphite S(alpha, beta) data are quantified by coupling the standard methodology of LEAPR with a Monte Carlo sampling process. The mechanics of efficiently representing and processing this covariance information is also examined. Finally, with appropriate sensitivity information, it is shown that an S(alpha, beta) covariance matrix can be propagated to generate covariance data for integrated cross sections, secondary energy distributions, and coupled energy-angle distributions. This approach enables a complete description of thermal neutron inelastic scattering cross section uncertainties which may be employed to improve the simulation of nuclear systems.

  10. Trace uranium analysis in geological sample by isotope dilution-alpha spectrometry and comparison with other techniques

    International Nuclear Information System (INIS)

    Shihomatsu, H.M.; Iyer, S.S.

    1988-12-01

    Establishment of uranium determination in geological samples by alpha spectrometric isotope dilution technique using 233 U tracer is described in the present work. The various steps involved in the method namely, preparation of the sample, electrodeposition, alpha spectrometry, isotope dilution, calculation of the concentration and error statistics are discussed in detail. The experimental parameters for the electrodeposition of uranium, like current density, pH concentration of the electrolyte solution, deposition time, electrode distance were all optimised based on the efficiency of the deposition. The total accuracy and precision of the IDAS using 233 U tracer in the determination of uranium in mineral and granite samples were of the order of 1 to 2% for the concentration range of 50-1500 ppm of U. Our results are compared with those obtained by others workers using similar and different techniques. (author) [pt

  11. Determination of rhenium in biological and environmental samples by radiochemical neutron activation analysis

    International Nuclear Information System (INIS)

    Kucera, J.; Mizera, J.; Randa, Z.; Byrne, A.R.; Lucanikova, M.

    2006-01-01

    Radiochemical neutron activation procedures using liquid-liquid extraction with tetraphenylarsonium chloride in chloroform from 1 M HCl and solid extraction with ALIQUAT 336 incorporated in a polyacrylonitrile binding matrix from 0.1 M HCl were developed for accurate determination of rhenium in biological and environmental samples at the sub-ng.g -1 level. Concentrations of Re in the range of 0.1 to 2.4 ng.g -1 were determined in several botanical reference materials (RM), while in a RM of road dust a value of approx. 10 ng.g -1 was found. Significantly elevated values of Re, up to 90 ng.g -1 , were found in seaweed (brown algae). Results for Re in the brown algae Fucus vesiculosus in which elevated 99 Tc values had previously been determined suggest possible competition between Re and Tc in the accumulation process. (author)

  12. Concentration of mercury in wheat samples stored with mercury tablets as preservative. [Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Lalit, B Y; Ramachandran, T V [Bhabha Atomic Research Centre, Bombay (India). Air Monitoring Section

    1977-01-01

    Tablets consisting of mercury in the form of a dull grey powder made by triturating mercury with chalk and sugar are used in Indian household for storing food-grains. The contamination of wheat samples by mercury, when stored with mercury tablets for period of upto four years has been assessed by using non-destructive neutron activation analysis. The details of the analytical procedure used have also been briefly described. The concentration of mercury in wheat increases with storage period. Loss of weight of mercury tablet is proportional to the storage period to a first approximation. In the present experiment, the average weight loss at the and end of first year was 0.009716 g corresponding to 6 ppm in wheat.

  13. Multielemental analysis of Brazilian milk powder and bread samples by neutron activation

    International Nuclear Information System (INIS)

    Maihara, V.A.; Vasconcellos, M.B.A.

    1988-01-01

    The concentrations of Na, Cl, Mn, Br, Fe, Zn, Rb, Sb, Sc, Cr, Al and Mg were determined in some types of bread and in some brands of milk powder consumed in the city of Sao Paulo (SP - Brasil), by instrumental neutron activation analysis. Radiochemical separations were carried out by means of retention of 24 Na on hydrated antimony pentoxide (HAP) from a 8N HCl solution, after digestion of the organic matter. Thus the radioisotopes 64 Cu, 69m Zn and 140 La could be determined in the effluent solution. The detection limits of the trace elements analyzed in bread and milk powder samples were determined using the Currie and Girardi criterions. (author) 22 refs.; 2 figs.; 7 tabs

  14. Measurement of arsenic in sectioned hair samples by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Guinn, V.P.; Gavrilas-Guinn, M.; Demiralp, R.

    1994-01-01

    In a recent Texas murder case, bundles of head hair from the female victim (aligned with all root ends together) were washed, cut into 7 mm sections, air-dried and weighed, activated in a nuclear reactor neutron flux, and then counted with a Ge(Li) detector/4096-channel gamma-ray spectrometer. In each of the 15 samples, the 559 keV gamma-ray peak of 26.3 hour 76 As was measured. In the section closest to the scalp, an arsenic concentration of 107 ppm was found (cf. a 'normal' level of about 1 ppm As). Barium ingestion was also possible so Ba was looked for, but not found. The victim's husband was found guilty of murder by chronic arsenic poisoning. (author) 2 refs.; 1 fig.; 1 tab

  15. Thermal neutron absorption cross-section measured on rock samples and brines in the Institute of Nuclear Physics

    International Nuclear Information System (INIS)

    Czubek, J.A.; Drozdowicz, K.; Krynicka-Drozdowicz, E.; Igielski, A.; Woznicka, U.

    1983-01-01

    In consecutive measurements the rock sample (having a fixed and well known shape -in our case it is a sphere or a cylinder and the sample is powdered or liquid) is enveloped in shells of a plexiglass moderator (the neutron parameters of which are known) of variable thickness and irradiated with the pulsed beam of fast neutrons. The die-away rate of thermal neutrons escaping from the whole system is measured. The absorption cross-section of the sample is found as the intersection of the experimental curve (i.e. die -away rate vs thickness of the moderator) with the theoretical one. The theoretical curve is calculated for a given moderator under the assumption of a constant value of the neutron flux inside the sample. This method is independent of the value of the transport cross-section of the sample. It has been checked on artificial materials with a well known elemental composition (liquid or solid) and on the natural brines and rock samples (basalts and dolomite). A special method of calculation of the variance of the measurement has been established. It is based on the multiple computer simulations of all experimental data used in the computation. The one standard deviation of our methods is of the order of 1 up to 3 capture units (1 c.u. = 10 -3 cm -1 ). The volume of the sample needed is of the order of 500ccm. (author)

  16. Application of high resolution x-ray spectrometry preceded by neutron activation for elemental analysis of soil samples

    International Nuclear Information System (INIS)

    Hernandez Rivero, A.; Capote Rodriguez, G.; Padilla Alvarez, R.; Herrera Peraza, E.

    1997-01-01

    Utilization of High Resolution X-Ray Spectrometry preceded by activation of the samples by irradiation with neutron fluxes (NAA-RX) is a relatively modern trend in application of nuclear techniques. This method may complement advantageously the usual Neutron Activation Analysis by means of Gamma Spectrometry (NAA-G). In this work results obtained by the application of NAA-RX for non-destructive analysis of Cuban soil samples are discussed. The samples were irradiated with reactor neutron fluxes and the induced characteristic X-rays were measured by using Si(Li)-detector. Concentrations of Fe, Zn and Eu as determined by NAA-RX are compared with both NAA-G and XRF data. For the elaboration of X-Ray and Gamma Spectra the computer programs AXIL and ACTAN were used respectively. (author) [es

  17. Application of high resolution x-ray spectrometry preceded by neutron activation for elemental analysis of soil samples

    International Nuclear Information System (INIS)

    Hernandez Rivero, A.; Capote Rodriguez, G.; Herrera Peraza, E.

    1996-01-01

    Utilization of High Resolution X-Ray Spectrometry preceded by activation of the samples by irradiation with neutron fluxes (NAA R X) is a relatively modern trend in application of nuclear techniques. This method may complement advantageously the usual Neutron Activation Analysis by means of Gamma Spectrometry (NAA-G) In this work results obtained by the application of NAA-RX for non-destructive analysis of Cuban soil samples are discussed. The samples were irradiated with reactor neutron fluxes and the induced characteristic X-rays were measured by using Si(li)-detector. Concentrations of Fe, Zn and Eu as determined by NAA-RX are compared with both NAA-G and XRF data. For the elaboration of X-ray and Gamma Spectra the computer programs AXIL and ACTAN were used respectively

  18. APPLICATION OF NEUTRON ACTIVATION ANALYSIS IN CHARACTERIZATION OF ENVIRONMENTAL SRM SAMPLES

    Directory of Open Access Journals (Sweden)

    Diah Dwiana Lestiani

    2010-06-01

    Full Text Available Neutron activation analysis (NAA is a nuclear technique that is excellent, multi-elemental, sensitive and has limit detection up to nanogram level. The application of NAA in analysis of Standard Reference Material (SRM National Institute of Standard Technology (NIST 1633b Coal Fly Ash and SRM NIST 1646a Estuarine Sediment was carried out for NAA laboratory inter-comparison program. The samples were distributed by Technology Centre for Nuclear Industry Material, National Nuclear Energy Agency as a coordinator of the inter-comparison program. The samples were irradiated in rabbit facility of G.A. Siwabessy reactor with neutron flux ~ 1013 n.cm-2.s-1, and counted with HPGe spectrometry gamma detector. Several trace elements in these samples were detected. The concentration of Al, Mg, K, Na and Ti in SRM NIST 1633b were 15.11, 7.35, 2.09, 0.192 and 0.756% respectively and the concentration of As, Cr, Mn, Se, V, Sb, Co, Cs, La, Sc and Sm were 137.0, 195.6, 129.4, 9.61, 305.8, 5.45, 56.2, 11.18, 83.73, 41.1 and 19.13 mg/kg respectively. The analysis result in SRM NIST 1646a of the concentration of Al and Na were 2.15 and 0.70% and the concentration of As, Cr, Co, La and Sc were 5.75, 36.3, 4.58, 15.67 and 4.00 mg/kg respectively. These results analysis had relative bias and u-test ranged from 0.4-11.3% and 0.15-2.25. The accuracy and precision evaluation based on International Atomic Energy Agency (IAEA criteria was also applied. The result showed that NAA technique is applicable for the environmental samples analysis, and it also showed that the NAA laboratory in BATAN Bandung has a good performance.   Keywords: NAA, inter-comparison, estuarine sediment, coal fly ash, environmental samples

  19. Measurement of C and N isotopes of geological samples using Delta V Plus Stable Isotope Ratio Mass Spectrometer via different preparatory systems

    Digital Repository Service at National Institute of Oceanography (India)

    Karapurkar, S.; Methar, A.; Agnihotri, R.

    standard developed for routine C and N isotope analyses of various types of geological samples containing organic matter in order to assess stabilities/ reproducibility of the IRMS in different time windows....

  20. Archive of Geosample Data and Information from the University of Rhode Island (URI) Graduate School of Oceanography (GSO), Marine Geological Samples Laboratory (MGSL)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Geological Samples Laboratory (MGSL) of the Graduate School of Oceanography (GSO), University of Rhode Island is a partner in the Index to Marine and...

  1. Determination of rhenium in geologic samples of sandstone-type uranium deposit

    International Nuclear Information System (INIS)

    Li Yanan; Wang Xiuqin; Yin Jinshuang

    1997-01-01

    The thiourea colorimetry method suitable for the determination of samples with rhenium content higher than 5 μg/g is described. The method is characterized by many advantages: stability of analytical results, simplicity and cheapness of reagent, and wide range of analysed samples. The catalytic colorimetry is also applied to determine trace rhenium meeting the demand for comprehensive appraisal of prospecting and exploration, recovery and utilization of rhenium. This method can also be applied to analyse rhenium of other samples

  2. Test of Fibre Bragg Gratings samples under High Fast Neutrons Fluence

    Science.gov (United States)

    Cheymol, G.; Remy, L.; Gusarov, A.; Kinet, D.; Mégret, P.; Laffont, G.; Blanchet, T.; Morana, A.; Marin, E.; Girard, S.

    2018-01-01

    Optical fibre sensors (OFS) are worthy of interest for measurements in nuclear reactor thanks to their unique features, particularly compact size and remote multi-point sensing for some of them. But besides non negligible constraints associated with the high temperature environment of the experiments of interest, it is well known that the performances of OFS can be severely affected by high level of radiations. The Radiation Induced Attenuation (RIA) in the fibre is probably most known effect, which can be to some extent circumvented by using rad hard fibres to limit the dynamic loss. However, when the fast neutron fluence reaches 1018 to 1019 n/cm2, the density and index variations associated to structural changes may deteriorate drastically the performances of OFS even if they are based on rad hard fibres, by causing direct errors in the measurements of temperature and/or strain changes. The aim of the present study is to access the effect of nuclear radiations on the Fabry Perot (FP) and of Fibre Bragg Grating (FBG) sensors through the comparison of measurements made on these OFS - or part of them - before and after irradiation [1]. In the context of development of OFS for high irradiation environment and especially for Material Testing Reactors (MTRs), Sake 2 experiment consists in an irradiation campaign at high level of gamma and neutron fluxes conducted on samples of fibre optics - bare or functionalised with FBG. The irradiation was performed at two levels of fast neutron fluence: 1 and 3.1019 n/cm2 (E>1MeV), at 250°± 25°C, in the SCK•CEN BR2 reactor (Mol Belgium). An irradiation capsule was designed to allow irradiation at the specified temperature without active control. The neutron fluence was measured with activation dosimeters and the results were compared with MCPN computations. Investigation of bare samples gives information on the density changes, while for the FBGs both density and refractive index perturbation are involved. Some results for

  3. Determination of trace elements in lichen samples by neutron activation analysis

    International Nuclear Information System (INIS)

    Saiki, Mitiko; Coccaro, D.M.B.; Vasconcellos, M.B.A.; Marcelli, M.P.

    1999-01-01

    Epiphytic lichens have been used as bioindicators of environmental pollution studies because of their ability to accumulate metals present in the atmosphere at very low concentrations. In this work, experimental conditions for collection and preparation of the lichen samples as well as the experimental procedure for neutron activation analysis were established in order to obtain reliable and useful data for environmental monitoring purposes. Lichen samples were collected from the barks of trees. They were first examined in a stereo microscope, cleaned and then they were washed with water, freeze-dried and ground for analysis. Out of the five species Usnea sp, Parmotrena tinctorum, Canoparmelia caroliniana, Parmotrema sanctiangeli and Canoparmelia texana analysed, the latter was chosen for this work since this species is very abundant on the Brazilian territory except for the coast. The samples and synthetic standards of elements were irradiated at the IEA-R1 nuclear reactor and the concentrations of the elements Al, As, Br, Ca, Cd, Cl, Co, Cr, Cs, Fe, K, lanthanides, Mg, Mn, Na, Rb, Sb, Sc, Se, Th, U, V and Zn were determined by using short and long irradiations. Results obtained in the washed and unwashed lichen samples showed that the cleaning with water can be used in order to eliminate adhering materials. Indeed, most of elements of interest for the environmental contamination accumulated by the lichens were not removed. The study of the influence of the age of the lichen indicated that its elemental concentrations increase with its age or with the length of exposure. Results obtained for lichens collected from four different trees in the same sampling area varied from about 3.4 to 50%. The homogeneity of the sample was checked by analyzing replicates. The precision and the accuracy of the method were evaluated by analyzing IAEA 336 Lichen and NIST 1752 Citrus Leaves. (author)

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  5. Determination of elemental concentrations in environmental plant samples by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Datta, J.; Chowdhury, D.P.; Verma, R.; Reddy, A.V.R.

    2012-01-01

    The intake of leafy vegetables in daily diet is very important to meet our nutritional needs. Vegetables provide the essential elements which are necessary and recommended for human growth. However, due to rapid industrialization and urbanization our environment becomes polluted and this affects the normal growth of agricultural products and composition of environmental species. The elemental concentrations present in the environmental samples are good indicators to assess the toxicological levels due to pollution affects. In the present work we have analysed several vegetable plant samples by instrumental neutron activation analysis to determine the elemental concentrations at major, minor and trace levels. The leafy vegetables like spinach, red leafy vegetable, pui, gourd leaf, lettuce and katoua were chosen as these are extensively consumed by local people in eastern part of India. We have determined 15 elements in the above mentioned vegetable samples and some of these are essential elements and some are toxic elements. It was found that Na and K were present as major elements, Fe and Zn as minor elements and As, Ce, Cr, Co, La, Mo, Rb, Sc, Sm, Sr as trace elements. The concentration level of Cr was found to be higher than that of recommended value certified by WHO and National environment quality control for human consumption. The validation of our analytical results have been performed by the Z-score tests through the determination of concentrations of the elements of interest in certified reference materials. (author)

  6. A hydrogen leak-tight, transparent cryogenic sample container for ultracold-neutron transmission measurements

    Science.gov (United States)

    Döge, Stefan; Hingerl, Jürgen

    2018-03-01

    The improvement of the number of extractable ultracold neutrons (UCNs) from converters based on solid deuterium (sD2) crystals requires a good understanding of the UCN transport and how the crystal's morphology influences its transparency to the UCNs. Measurements of the UCN transmission through cryogenic liquids and solids of interest, such as hydrogen (H2) and deuterium (D2), require sample containers with thin, highly polished and optically transparent windows and a well defined sample thickness. One of the most difficult sealing problems is that of light gases like hydrogen and helium at low temperatures against high vacuum. Here we report on the design of a sample container with two 1 mm thin amorphous silica windows cold-welded to aluminum clamps using indium wire gaskets, in order to form a simple, reusable, and hydrogen-tight cryogenic seal. The container meets the above-mentioned requirements and withstands up to 2 bar hydrogen gas pressure against isolation vacuum in the range of 10-5 to 10-7 mbar at temperatures down to 4.5 K. Additionally, photographs of the crystallization process are shown and discussed.

  7. Investigation of two slag samples using k0 neutron activation analysis through different standardization methods

    Directory of Open Access Journals (Sweden)

    M. Abd El-Samad

    2010-12-01

    Full Text Available Instrumental neutron activation analysis was used to determine concentrations of several major and trace elements in two slag samples. One slag supplied by one of Steel factory and the other one by an Aluminum factory of Egypt. The aim of the present work is to study the accuracy and precision of Internal Comparator k0 and external comparator k0 methods in industrial application. The two slag samples together with an international reference material Soil-7 and two thin gold foils samples (one bare and the other covered with cadmium were irradiated at the core of the Second Research Egyptian Reactor ET-RR-2 of about 13x10 13n/(cm s. The elemental concentration of 46Sc, 51Cr, 60Co, 65Zn, 74As, 82Br, 85Sr, 86Zr, 110mAg, 122Sb, 134Cs, 131Ba, 140La, 141Ce, 147Nd, 153Sm, 152Eu, 153Gd, 166Ho, 169Yb, 175Hf, 182Ta, 198Au and 233Pa (232Th-series were calculated.

  8. Comparison between conservative perturbation and sampling based methods for propagation of Non-Neutronic uncertainties

    International Nuclear Information System (INIS)

    Campolina, Daniel de A.M.; Pereira, Claubia; Veloso, Maria Auxiliadora F.

    2013-01-01

    For all the physical components that comprise a nuclear system there is an uncertainty. Assessing the impact of uncertainties in the simulation of fissionable material systems is essential for a best estimate calculation that has been replacing the conservative model calculations as the computational power increases. The propagation of uncertainty in a simulation using sampling based method is recent because of the huge computational effort required. In this work a sample space of MCNP calculations were used as a black box model to propagate the uncertainty of system parameters. The efficiency of the method was compared to a conservative method. Uncertainties in input parameters of the reactor considered non-neutronic uncertainties, including geometry dimensions and density. The effect of the uncertainties on the effective multiplication factor of the system was analyzed respect to the possibility of using many uncertainties in the same input. If the case includes more than 46 parameters with uncertainty in the same input, the sampling based method is proved to be more efficient than the conservative method. (author)

  9. A hydrogen leak-tight, transparent cryogenic sample container for ultracold-neutron transmission measurements.

    Science.gov (United States)

    Döge, Stefan; Hingerl, Jürgen

    2018-03-01

    The improvement of the number of extractable ultracold neutrons (UCNs) from converters based on solid deuterium (sD 2 ) crystals requires a good understanding of the UCN transport and how the crystal's morphology influences its transparency to the UCNs. Measurements of the UCN transmission through cryogenic liquids and solids of interest, such as hydrogen (H 2 ) and deuterium (D 2 ), require sample containers with thin, highly polished and optically transparent windows and a well defined sample thickness. One of the most difficult sealing problems is that of light gases like hydrogen and helium at low temperatures against high vacuum. Here we report on the design of a sample container with two 1 mm thin amorphous silica windows cold-welded to aluminum clamps using indium wire gaskets, in order to form a simple, reusable, and hydrogen-tight cryogenic seal. The container meets the above-mentioned requirements and withstands up to 2 bar hydrogen gas pressure against isolation vacuum in the range of 10 -5 to 10 -7 mbar at temperatures down to 4.5 K. Additionally, photographs of the crystallization process are shown and discussed.

  10. Absolute activity determinations on large volume geological samples independent of self-absorption effects

    International Nuclear Information System (INIS)

    Wilson, W.E.

    1980-01-01

    This paper describes a method for measuring the absolute activity of large volume samples by γ-spectroscopy independent of self-absorption effects using Ge detectors. The method yields accurate matrix independent results at the expense of replicative counting of the unknown sample. (orig./HP)

  11. OPERATION OF A PUBLIC GEOLOGIC CORE AND SAMPLE REPOSITORY IN HOUSTON TEXAS

    Energy Technology Data Exchange (ETDEWEB)

    Scott W. Tinker

    2003-06-01

    In the spring of 2002, the Department of Energy provided an initial 1-year grant to the Bureau of Economic Geology (BEG) at The University of Texas at Austin (UT). The grant covered the one-year operational expenses of a worldclass core and cuttings facility located in Houston, Texas, that BP America donated to the BEG. The DOE investment of $300,000, matched by a $75,000 UT contribution, provided critical first-year funds that were heavily leveraged by the BP gift of $7.0 million in facilities and cash. DOE also provided a one-month extension and grant of $30,000 for the month of May 2003. A 5-year plan to grow a permanent endowment in order to manage the facility in perpetuity is well under way and on schedule. The facility, named the Houston Research Center, represents an ideal model for a strong Federal, university, and private partnership to accomplish a national good. This report summarizes the activities supported by the initial DOE grant during the first 13 months of operation and provides insight into the activities and needs of the facility in the second year of operation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-03

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

  13. Partial Least Squares and Neural Networks for Quantitative Calibration of Laser-induced Breakdown Spectroscopy (LIBs) of Geologic Samples

    Science.gov (United States)

    Anderson, R. B.; Morris, Richard V.; Clegg, S. M.; Humphries, S. D.; Wiens, R. C.; Bell, J. F., III; Mertzman, S. A.

    2010-01-01

    The ChemCam instrument [1] on the Mars Science Laboratory (MSL) rover will be used to obtain the chemical composition of surface targets within 7 m of the rover using Laser Induced Breakdown Spectroscopy (LIBS). ChemCam analyzes atomic emission spectra (240-800 nm) from a plasma created by a pulsed Nd:KGW 1067 nm laser. The LIBS spectra can be used in a semiquantitative way to rapidly classify targets (e.g., basalt, andesite, carbonate, sulfate, etc.) and in a quantitative way to estimate their major and minor element chemical compositions. Quantitative chemical analysis from LIBS spectra is complicated by a number of factors, including chemical matrix effects [2]. Recent work has shown promising results using multivariate techniques such as partial least squares (PLS) regression and artificial neural networks (ANN) to predict elemental abundances in samples [e.g. 2-6]. To develop, refine, and evaluate analysis schemes for LIBS spectra of geologic materials, we collected spectra of a diverse set of well-characterized natural geologic samples and are comparing the predictive abilities of PLS, cascade correlation ANN (CC-ANN) and multilayer perceptron ANN (MLP-ANN) analysis procedures.

  14. Cadmium determination in biological samples using neutron activation analysis with radiochemical separations

    International Nuclear Information System (INIS)

    Munoz A, Luis; Gras R, Nuri

    2005-01-01

    Chile has 7500 km of coastline on the Southern Pacific ocean,with about 4500 km of continental coastline that contains a variety of different geographical zones.This variety means that there is a great diversity of marine resources such as fish, shellfish and seaweeds. The utilization of these resources has been increasing in recent years making this sector an economically important one. The catch as of May 2002 came to 1.9 million tons and exports of the different species amounted to US$611.5 million as of April.But this important economic resource is being threatened by the technical demands imposed by importing countries, mainly the specific requirements for sanitary certification for fishery export products, depending on the markets of destination. The chemical element cadmium is one of the most strictly controlled elements due some shellfish accumulate a large amount of this element and to its high toxicity. The Chilean standard's analytical procedures for cadmium determination in hydro biological products, which must be met by laboratories that certify and control these products for export, are now being evaluated. Through its Chemical Metrology Unit, the Chilean Nuclear Energy Commission is strongly supporting this sector by preparing the secondary reference or control materials, and it has developed and implemented nuclear analytical methods for the certification of these materials, which will be used mostly in collaborative studies. This work describes the methodology developed for the determination of cadmium in biological samples, particularly in shellfish and fish. The method is based on neutron activation analysis with radiochemical separations, using the radioisotopes 115 Cd and 115m In, generated in the samples by bombarding with neutrons in a nuclear reactor. The samples were digested at 110 o C with H 2 SO 4 and H 2 O 2 and then the radioactive cadmium element was separated from the other elements present in the samples using a Bio Rad AG 2-X8

  15. Identification of cadmium in biological samples using neutron activation analysis with radiochemistry separations

    International Nuclear Information System (INIS)

    Munoz A, Luis; Gras R, Nuri

    2002-01-01

    Chile's 7500 km coastline of the Southern Pacific ocean, with about 4500 km of continental coastline that contains a variety of different geographical zones. This variety means that there is a great diversity of marine resources such as fish, shellfish and seaweeds. The utilization of these resources has been increasing in recent years making this sector an economically important one. The catch as of May 2002 came to 1.9 million tons and exports of the different species amounted to US$611.5 million as of April. But this important economic resource is being threatened by the technical demands imposed by importing countries, mainly the specific requirements for sanitary certification for fishery export products, depending on the markets of destination. The chemical element cadmium is one of the most strictly controlled elements due some shellfish accumulate a large amount of this element and to its high toxicity. The Chilean standard's analytical procedures for cadmium determination in hydro biological products, which must be met by laboratories that certify and control these products for export, are now being evaluated. Through its Chemical Metrology Unit, the Chilean Nuclear Energy Commission is strongly supporting this sector by preparing the secondary reference or control materials, and it has developed and implemented nuclear analytical methods for the certification of these materials, which will be used mostly in collaborative studies. This work describes the methodology developed for the determination of cadmium in biological samples, particularly in shellfish and fish. The method is based on neutron activation analysis with radiochemical separations, using the radioisotopes 115 Cd and 115m In, generated in the samples by bombarding with neutrons in a nuclear reactor. The samples were digested at 110 o C with H 2 SO 4 and H 2 O 2 and then the radioactive cadmium element was separated from the other elements present in the samples using a Bio Rad AG 2-X8 resin

  16. Computer graphics for quality control in the INAA of geological samples

    International Nuclear Information System (INIS)

    Grossman, J.N.; Baedecker, P.A.

    1987-01-01

    A data reduction system for the routine instrumental activation analysis of samples is described, with particular emphasis on interactive graphics capabilities for evaluating analytical quality. Graphics procedures were developed to interactively control the analysis of selected photopeaks during spectral analysis, and to evaluate detector performance during a given counting cycle. Graphics algorithms are also used to compare the data on reference samples with accepted values, to prepare quality control charts to evaluate long term precision and to search for systematic variations in data on reference samples as a function of time. (author)

  17. Computer graphics for quality control in the INAA of geological samples

    Science.gov (United States)

    Grossman, J.N.; Baedecker, P.A.

    1987-01-01

    A data reduction system for the routine instrumental activation analysis of samples is described, with particular emphasis on interactive graphics capabilities for evaluating analytical quality. Graphics procedures have been developed to interactively control the analysis of selected photopeaks during spectral analysis, and to evaluate detector performance during a given counting cycle. Graphics algorithms are also used to compare the data on reference samples with accepted values, to prepare quality control charts to evaluate long term precision and to search for systematic variations in data on reference samples as a function of time. ?? 1987 Akade??miai Kiado??.

  18. The development of an automatic sample-changer and control instrumentation for isotope-source neutron-activation analysis

    International Nuclear Information System (INIS)

    Andeweg, A.H.; Watterson, J.I.W.

    1983-01-01

    An automatic sample-changer was developed at the Council for Mineral Technology for use in isotope-source neutron-activation analysis. Tests show that the sample-changer can transfer a sample of up to 3 kg in mass over a distance of 3 m within 5 s. In addition, instrumentation in the form of a three-stage sequential timer was developed to control the sequence of irradiation transfer and analysis

  19. Application of neutron activation analysis technique in elemental determination of lichen samples

    International Nuclear Information System (INIS)

    Djoko Prakoso Dwi Atmodjo; Syukria Kurniawati; Woro Yatu Niken Syahfitri; Nana Suherman; Dadang Supriatna

    2010-01-01

    Lichen is one of the biological materials as pollution monitor that can give information about level, direction, and history of various pollutants in environment. Small sample weights and elemental content of lichens is on the order of ppm, so that its characterization requires advanced analytical techniques that has high sensitivity and capable of analyzing samples with weight of - 25 mg, such as neutron activation analysis. In this research, determination of elements was done in lichen samples obtained from Kiaracondong and Holis areas in Bandung city, to understanding the difference of industrial exposure level on surrounding environment. Samples were irradiated in RSG GA Siwabessy, Serpong, at 15 MW for 1-2 and 60 minutes for short irradiation and long irradiation, respectively. The samples were then counted using HPGe detector with GENIE 2000 software. The level of element in lichen for Kiaracondong area were Co, Cr, Cs, Fe, Mg, Mn, Sb, Sc, and V in the range of 0.55-0.86, 1.47-2.57, 0.87-1.19, 540-1005, 949-1674, 34.91-45.94, 0.08-0.14, 0.16-0.31, and ≤ 2.33 mg/kg, respectively, while for Holis area were 1.04-2.37, 4.41-10.36, 0.41-0.89, 3166-709, 1131-1422, 40.97-72.51, 0.33-0.50, 0.98-2.18, and 5.30-13.05 mg/kg respectively. From these results, it is known that pollution exposure from the semi industrial area Holis provide greater influence than in the semi industrial area Kiaracondong. (author)

  20. Determination of trace elements in lichen samples by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Saiki, Mitiko; Horimoto, Lidia K.; Vasconcellos, Marina B.A.; Marcelli, Marcelo P.; Sumita, Nairo M.; Saldiva, Paulo H.N.

    2001-01-01

    Samples of Canoparmelia texana lichen collected in different sites of Sao Paulo and Parana States, Brazil, were analysed by neutron activation analysis in order to obtain preliminary information on the air quality in these regions and also to select a region of interest for biomonitoring studies. Also Tadescantia pallida plant has been analysed in order to study the viability of using this specimen in environmental pollution monitoring. Lichens samples were collected from tree barks which were also collected to investigate the contribution of substrate derived elements to elements present in lichens. Young and old leaves of T. pallida were collected separately in order to study the leaf age effects on their elemental levels. The samples were cleaned, washed with distilled water, dried and ground for the analyses. Samples and standards were irradiated at the IEA-Rlm nuclear reactor for short and long periods and concentrations of the elements Al, As, Ca, Cd, Cl, Co, Cr, Cs, Fe, Hf, Mg, Mn, Rb, Sb, Sc, D, Th, U, V Zn and lanthanides were determined. Preliminary results obtained for T. texana lichen indicated that three sites (Ibiuna, Botanical Garden and Parque de Vila Velha) present low concentrations of the most elements analysed. Therefore lichens from these regions could be analysed to establish baseline levels of elements for monitoring purposes. Samples collected in open areas presented high concentrations of some elements probably due to the accumulation of elements originating from soil and from heavy vehicular traffic. Elemental concentrations obtained in outer barks were similar or smaller than those results obtained for lichens. Results obtained for T. pallida indicated that concentrations of elements in old leaves of this plant are of the same magnitude or slightly higher than those presented in young ones. (author)

  1. A novel procedure for Rubidium separation and its isotope measurements on geological samples by MC-ICP-MS

    Science.gov (United States)

    Ma, J.; Zhang, Z.; Wei, G.; Zhang, L.

    2017-12-01

    A method including a novel column Rb separation procedure and high-precision Rb isotope measurement in geological materials by using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) in standard-sample-bracketing (SSB) mode has been developed. Sr-Spec resin was employed, in which the distribution coefficients for Rb, K, Ba and Sr are different in nitric acid, to sequentially separate them from the matrix. The dissolved samples were loaded on the column in 3 M HNO3, the main matrix such as Al, Ca, Fe, Mg, Mn and Na were removed by rinsing with 4.5 mL HNO3, Rb and K were then sequentially eluted by 3 M HNO3 in different volumes. After that, Ba was eluted by 8 M HNO3, and Sr was finally eluted by Milli-Q water. This enable us to collect the pure Rb, K, Ba and Sr one by one with recovery close to 100% for their isotopic compositions measurement on MC-ICP-MS. We here focus on Rb isotope measurement. The measurement using MC-ICP-MS yielded an internal precision for δ87Rb of external precision was generally better than ± 0.06‰ (2SD) based on the long-term results of the Rb standard solutions NIST SRM 984. A series of geological rock standards, were analyzed using this method, and the results indicate significant Rb isotope differences in different geologic materials. This will provide a powerful tool to investigate Rb isotope fractionation during geological processes.Based on this method, Rb isotope compositions from a basaltic weathering profile were carried out. The data show the lighter Rb (85Rb) isotope is preferentially leached from the weathering profile and remains heavy Rb isotope (87Rb) in the weathered residues during the incipient weathering stage. From the moderate to advanced weathering stage, the significant variations of Rb isotope were observed and multiple factors, such as leaching, adsorption, desorption, and precipitation, should play important role in fractionating Rb isotope.

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

    International Nuclear Information System (INIS)

    Ku, L.; Kolibal, J.G.

    1982-06-01

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

  3. Neutron activation analysis of archaeological artifacts using the conventional relative method: a realistic approach for analysis of large samples

    International Nuclear Information System (INIS)

    Bedregal, P.S.; Mendoza, A.; Montoya, E.H.; Cohen, I.M.; Universidad Tecnologica Nacional, Buenos Aires; Oscar Baltuano

    2012-01-01

    A new approach for analysis of entire potsherds of archaeological interest by INAA, using the conventional relative method, is described. The analytical method proposed involves, primarily, the preparation of replicates of the original archaeological pottery, with well known chemical composition (standard), destined to be irradiated simultaneously, in a well thermalized external neutron beam of the RP-10 reactor, with the original object (sample). The basic advantage of this proposal is to avoid the need of performing complicated effect corrections when dealing with large samples, due to neutron self shielding, neutron self-thermalization and gamma ray attenuation. In addition, and in contrast with the other methods, the main advantages are the possibility of evaluating the uncertainty of the results and, fundamentally, validating the overall methodology. (author)

  4. Analysis of some Egyptian cosmetic samples by fast neutron activation analysis

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  5. Analysis of Some Egyptian Cosmetic Samples by Fast Neutron Activation Analysis

    CERN Document Server

    Medhat, M E; Fayez-Hassan, M

    2001-01-01

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

  6. High-resolution room-temperature sample scanning superconducting quantum interference device microscope configurable for geological and biomagnetic applications

    Science.gov (United States)

    Fong, L. E.; Holzer, J. R.; McBride, K. K.; Lima, E. A.; Baudenbacher, F.; Radparvar, M.

    2005-05-01

    We have developed a scanning superconducting quantum interference device (SQUID) microscope system with interchangeable sensor configurations for imaging magnetic fields of room-temperature (RT) samples with submillimeter resolution. The low-critical-temperature (Tc) niobium-based monolithic SQUID sensors are mounted on the tip of a sapphire and thermally anchored to the helium reservoir. A 25μm sapphire window separates the vacuum space from the RT sample. A positioning mechanism allows us to adjust the sample-to-sensor spacing from the top of the Dewar. We achieved a sensor-to-sample spacing of 100μm, which could be maintained for periods of up to four weeks. Different SQUID sensor designs are necessary to achieve the best combination of spatial resolution and field sensitivity for a given source configuration. For imaging thin sections of geological samples, we used a custom-designed monolithic low-Tc niobium bare SQUID sensor, with an effective diameter of 80μm, and achieved a field sensitivity of 1.5pT/Hz1/2 and a magnetic moment sensitivity of 5.4×10-18Am2/Hz1/2 at a sensor-to-sample spacing of 100μm in the white noise region for frequencies above 100Hz. Imaging action currents in cardiac tissue requires a higher field sensitivity, which can only be achieved by compromising spatial resolution. We developed a monolithic low-Tc niobium multiloop SQUID sensor, with sensor sizes ranging from 250μm to 1mm, and achieved sensitivities of 480-180fT /Hz1/2 in the white noise region for frequencies above 100Hz, respectively. For all sensor configurations, the spatial resolution was comparable to the effective diameter and limited by the sensor-to-sample spacing. Spatial registration allowed us to compare high-resolution images of magnetic fields associated with action currents and optical recordings of transmembrane potentials to study the bidomain nature of cardiac tissue or to match petrography to magnetic field maps in thin sections of geological samples.

  7. Neutron activation analysis of Permian-Triassic boundary layer samples at the Selong Site in China

    International Nuclear Information System (INIS)

    Miyamoto, Y.; Sakamoto, K.; Mingqing, W.

    1997-01-01

    Thirty samples from a limestone stratum across the Permian-Triassic (P-Tr) boundary layer in China were analyzed for 30 elements by instrumental neutron activation analysis, wavelength dispersive X-ray fluorescence and ICP-MS, and also for mineral compositions with a powder X-ray diffractometer. The depth profile was found to indicate a sudden change of elemental and mineral compositions across the P-Tr boundary. Also the profile showed several peaks in elemental concentrations in the lower Permian layered samples as well as in the overlying Triassic strata, which are associated with the change of mineral compositions. Elemental profiles were found to be classified into 4 groups and to give some insights in the geochemical records. Ir is far less abundant (0.1 ppt) compared with that of the K-T boundaries (10 ppb), and the Ir/Co ratio is outside the K-T and Cl chondrite trends. This change of elementary profile is suggestive of the internal causes rather than the external ones such as an asteroid impact for the mass extinction at the P-Tr boundary. (author)

  8. Determination of essential elements in dietetic sample by neutron activation analysis

    International Nuclear Information System (INIS)

    Siquelli, Murilo V.; Maihara, Vera A. Maihara

    2005-01-01

    In the last years there has been an increase of the dietetic product consumption by people who suffer from diabetes, heart disease and by people concerned about having a healthy life as well. Despite the increase of dietetic product presents in the diet of the Brazilian population, the use of these products is still controversial. The analysis of the nutritional composition of these products is becoming important because a great number of people is changing their traditional food by dietetic products. In the literature, there is no information about the inorganic composition, mainly related to the essential elements, in the dietetic products: diet and light . In this study are presented preliminary results of the concentrations of Br, Ca, Cr, Fe, Na and Zn determined by Instrumental Neutron Activation Analysis in aspartame, saccharin and cyclamate sodium , and stevia based sweetener samples. Gelatin samples, diet and light, were also analyzed. Methodology validation was done analyzing NIST reference materials Tea Leaves (INCT-TL-1) and Mixed Polish Herbs (INCT-MPH-2). (author)

  9. Neutron activation analysis of 127I and 129I environmental samples

    International Nuclear Information System (INIS)

    Takeishi, Minoru; Namiki, Atsushi; Ishida, Junichiro; Iwai, Makoto

    1987-01-01

    The analytical method of 127 I and 129 I in environmental samples has been studied and the background levels of these nuclides in soils, seaweeds and milk were measured. The analytical method consists of the combustion technique and neutron activation analysis (N.A.A.). The iodine was separated from samples by ignition at about 1,000 deg C in a quartz combustion apparatus with an oxygen and a nitrogen stream, and was absorbed by small amounts of active charcoal. The iodine was then purified through the carbontetrachloride extraction method and the PdI 2 decomposition method. Irradiation was conducted by JRR-4 (n th : 8 x 10 13 n/cm 2 · sec) for 40 min. After irradiation, the iodine was purified by the solvent extraction method same as pre-irradiation extraction. Each activity of 126 I and 130 I, which was produced by 127 I(n,2n) 126 I and 129 I(n,γ) 130 I reaction respectively, was measured by γ-spectrometry using a Ge-detector. The lower detection limits of 129 I by this method were 4 x 10 -7 Bq/g for dry soil, 7 x 10 -8 Bq/g for fresh seaweeds and 7 x 10 -6 Bq/l for fresh milk, respectively. The relative standard deviation of 129 I measurements in soil and milk were less than 10 %. (author)

  10. Neutron activation analysis for the optimal sampling and extraction of extractable organohalogens in human hari

    International Nuclear Information System (INIS)

    Zhang, H.; Chai, Z.F.; Sun, H.B.; Xu, H.F.

    2005-01-01

    Many persistent organohalogen compounds such as DDTs and polychlorinated biphenyls have caused seriously environmental pollution problem that now involves all life. It is know that neutron activation analysis (NAA) is a very convenient method for halogen analysis and is also the only method currently available for simultaneously determining organic chlorine, bromine and iodine in one extract. Human hair is a convenient material to evaluate the burden of such compounds in human body and dan be easily collected from people over wide ranges of age, sex, residential areas, eating habits and working environments. To effectively extract organohalogen compounds from human hair, in present work the optimal Soxhelt-extraction time of extractable organohalogen (EOX) and extractable persistent organohalogen (EPOX) from hair of different lengths were studied by NAA. The results indicated that the optimal Soxhelt-extraction time of EOX and EPOX from human hair was 8-11 h, and the highest EOX and EPOX contents were observed in hair powder extract. The concentrations of both EOX and EPOX in different hair sections were in the order of hair powder ≥ 2 mm > 5 mm, which stated that hair samples milled into hair powder or cut into very short sections were not only for homogeneous. hair sample but for the best hair extraction efficiency.

  11. Neutron activation analysis technique and X-ray fluorescence in bovine liver sample

    International Nuclear Information System (INIS)

    Maihara, V.A.; Favaro, D.I.T.; Vasconcellos, M.B.A.; Sato, I.M.; Salvador, V.L.

    2002-01-01

    Many analytical techniques have been used in food and diet analysis in order to determine a great number of nutritional elements, ranging from percentage to ng g -1 , with high sensitivity and accuracy. Instrumental Neutron activation Analysis (INAA) has been employed to certificate many trace elements in biological reference materials. More recently, the X-Ray Fluorescence (FRX-WD) has been also used to determine some essential elements in food samples. The INAA has been applied in nutrition studies in our laboratory at IPEN since the 80 s. For the development of analytical methodologies the use of the reference materials with the same characteristics of the sample analyzed is essential. Several Brazilian laboratories do not have conditions to use these materials due their high cost.In this paper preliminary results of commercial bovine liver sample analyses obtained by INAA and WD-XRF methods are presented. This sample was prepared to be a Brazilian candidate of reference material for a group of laboratories participating in a research project sponsored by FAPESP. The concentrations of some elements like Cl, K, Na, P, S and trace elements Br, Ca, Co, Cu, Fe, Mg, Mn, Mo, Rb, Se and Zn were determined by INAA and WD-XFR. For validation methodology of both techniques, NIST SRM 1577b Bovine Liver reference material was analyzed and the detection limits were calculated. The concentrations of elements determined by both analytical techniques were compared by using the Student's t-test and for Cl, Cu, Fe, K, Mg, Na, Rn and Zn the results do show no statistical difference for 95% significance level. (author)

  12. Major and trace elements in geological samples from Itingussu Basin in Coroa-Grande, RJ

    Energy Technology Data Exchange (ETDEWEB)

    Araripe, Denise R. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica; E-mail: drararipe@vm.uff.br; Bellido, Alfredo V.B.; Canesim, Fatima [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica. Dept. de Fisico-Quimica; Patchineelam, Sambasiva R.; Machdo, Edimar [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Geoquimica; Bellido, Luis F. [Instituto de Engenharia Nuclear IEN, Rio de Janeiro, RJ (Brazil); Vasconcelos, Marina B.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2005-07-01

    The goal of the present work was to characterize soil samples and sediment of mangrove belong the Itingussu river drainage basin, with a view to investigate the lithological signature of it. This small drainage ends in area not yet largely impacted by other sources such as industrial and domestic waste in relation to the elements studied here. The results showed some enrichment of the U,Th and some light rare earth elements in the Itingussu sediment sample. This represent the leucocratic rock signature, according to the normalized of data by upper crustal mean values . (author)

  13. Major and trace elements in geological samples from Itingussu Basin in Coroa-Grande, RJ

    International Nuclear Information System (INIS)

    Araripe, Denise R.; Vasconcelos, Marina B.A.

    2005-01-01

    The goal of the present work was to characterize soil samples and sediment of mangrove belong the Itingussu river drainage basin, with a view to investigate the lithological signature of it. This small drainage ends in area not yet largely impacted by other sources such as industrial and domestic waste in relation to the elements studied here. The results showed some enrichment of the U,Th and some light rare earth elements in the Itingussu sediment sample. This represent the leucocratic rock signature, according to the normalized of data by upper crustal mean values . (author)

  14. Scanning SQUID microscope with an in-situ magnetization/demagnetization field for geological samples

    Science.gov (United States)

    Du, Junwei; Liu, Xiaohong; Qin, Huafeng; Wei, Zhao; Kong, Xiangyang; Liu, Qingsong; Song, Tao

    2018-04-01

    Magnetic properties of rocks are crucial for paleo-, rock-, environmental-magnetism, and magnetic material sciences. Conventional rock magnetometers deal with bulk properties of samples, whereas scanning microscope can map the distribution of remanent magnetization. In this study, a new scanning microscope based on a low-temperature DC superconducting quantum interference device (SQUID) equipped with an in-situ magnetization/demagnetization device was developed. To realize the combination of sensitive instrument as SQUID with high magnetizing/demagnetizing fields, the pick-up coil, the magnetization/demagnetization coils and the measurement mode of the system were optimized. The new microscope has a field sensitivity of 250 pT/√Hz at a coil-to-sample spacing of ∼350 μm, and high magnetization (0-1 T)/ demagnetization (0-300 mT, 400 Hz) functions. With this microscope, isothermal remanent magnetization (IRM) acquisition and the according alternating field (AF) demagnetization curves can be obtained for each point without transferring samples between different procedures, which could result in position deviation, waste of time, and other interferences. The newly-designed SQUID microscope, thus, can be used to investigate the rock magnetic properties of samples at a micro-area scale, and has a great potential to be an efficient tool in paleomagnetism, rock magnetism, and magnetic material studies.

  15. Development of a radiochemical neutron activation analysis procedure for determination of rhenium in biological and environmental samples at ultratrace level

    Czech Academy of Sciences Publication Activity Database

    Kučera, Jan; Byrne, A. R.; Mizera, Jiří; Lučaníková, M.; Řanda, Zdeněk

    2006-01-01

    Roč. 269, č. 2 (2006), s. 251-257 ISSN 0236-5731 R&D Projects: GA ČR(CZ) GA203/04/0943 Institutional research plan: CEZ:AV0Z10480505 Keywords : radiochemical neutron activation analysis * rhenium * biological and environmental samples Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.509, year: 2006

  16. Determination of selenium in samples of concentrated of nickel plus cobalt using the analysis through activation with epi thermic neutron

    International Nuclear Information System (INIS)

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

    1997-01-01

    In this work, the concentration of selenium and other elements was determined. Seventeen samples of sulfides plus cobalt were used. Among the employed methods for such purpose, the analysis was made through neutronic activation, in its instrumental variants, and by means of the application of radiochemical separation. (author) [es

  17. A neutron capture gamma-ray system using isotopic neutron sources and its application for elemental analysis of some saudi samples

    International Nuclear Information System (INIS)

    Bahareth, R.; Alamoudi, Z.; Hassan, A.M.

    2005-01-01

    The design and construction of a prompt gamma-ray spectrometer using 226 R a/Be and 252 C f isotopic neutron sources are described. The characteristic curves of the system for energy and efficiency are presented. Elemental investigations of three Saudi samples [Table salt, Glass and Lubrication oil] have been done. For sake of comparison, the data obtained is compared with the results obtained for the same samples using different techniques. A discussion on the results as well as on the comparative studies is given

  18. X-ray fluorescence analysis of low concentrations metals in geological samples and technological products

    Science.gov (United States)

    Lagoida, I. A.; Trushin, A. V.

    2016-02-01

    For the past several years many nuclear physics methods of quantitative elemental analysis have been designed. Many of these methods have applied in different devices which have become useful and effective instrument in many industrial laboratories. Methods of a matter structure analysis are based on the intensity detection of the X-ray radiation from the nuclei of elements which are excited by external X-ray source. The production of characteristic X-rays involves transitions of the orbital electrons of atoms in the target material between allowed orbits, or energy states, associated with ionization of the inner atomic shells. One of these methods is X-ray fluorescence analysis, which is widespread in metallurgical and processing industries and is used to identify and measure the concentration of the elements in ores and minerals on a conveyor belt. Samples of copper ore with known concentrations of elements, were taken from the Ural deposit. To excite the characteristic X-rays radionuclide sources 109Cd, with half-life 461.4 days were used. After finding the calibration coefficients, control measurements of samples and averaging of overall samples were made. The measurement error did not exceed 3%.

  19. Fast neutron and gamma-ray transmission technique in mixed samples. MCNP calculations

    International Nuclear Information System (INIS)

    Perez, N.; Padron, I.

    2001-01-01

    In this paper the moisture in sand and also the sulfur content in toluene have been described by using the simultaneous fast neutron/gamma transmission technique (FNGT). Monte Carlo calculations show that it is possible to apply this technique with accelerator-based and isotopic neutron sources in the on-line analysis to perform the product quality control, specifically in the building materials industry and the petroleum one. It has been used particles from a 14MeV neutron generator and also from an Am-Be neutron source. The estimation of optimal system parameters like the efficiency, detection time, hazards and costs were performed in order to compare both neutron sources

  20. On the determination of iridium in diverse geological samples employing HPGe-coincidence/NaI(Tl)-anticoincidence spectrometry

    Science.gov (United States)

    Murali, A. V.; Parekh, P. P.; Cumming, J. B.

    1990-01-01

    This paper reports the Ir content of a variety of geological samples determined by the high-purity Ge-coincidence/NaI(Tl)-anticoincidence gamma-ray spectrometry (henceforth referred to as coincidence/anticoincidence technique) and by the conventional INAA. The advantages of this technique are: (1) the Ir content of the samples is obtained (ppm to a fraction of ppb ranges) not only by the 468.1 keV peak as in the conventional INAA but also by the 784.6 keV and 920.9 keV sum peaks, which gives more confidence in the values obtained; and (2) it is well suited for the samples with high Compton background for which it is difficult to measure the Ir content by the conventional INAA technique. The practical sensitivity of this technique depends on the sample matrix. Under present experimental conditions, it varied from 0.1 ng for Mn nodules and 0.004 ng for Libyan Desert Glass. Iridium values obtained on small (about 1 microg) olivine grains demonstrate the potential application of this new technique to microsamples. The principle and methodology of this new technique as well as its advantages and disadvantages over the conventional INAA are discussed.

  1. Correlated sampling added to the specific purpose Monte Carlo code McPNL for neutron lifetime log responses

    International Nuclear Information System (INIS)

    Mickael, M.; Verghese, K.; Gardner, R.P.

    1989-01-01

    The specific purpose neutron lifetime oil well logging simulation code, McPNL, has been rewritten for greater user-friendliness and faster execution. Correlated sampling has been added to the code to enable studies of relative changes in the tool response caused by environmental changes. The absolute responses calculated by the code have been benchmarked against laboratory test pit data. The relative responses from correlated sampling are not directly benchmarked, but they are validated using experimental and theoretical results

  2. Neutron-induced {sup 63}Ni activity and microscopic observation of copper samples exposed to the Hiroshima atomic bomb

    Energy Technology Data Exchange (ETDEWEB)

    Shizuma, Kiyoshi, E-mail: shizuma@hiroshima-u.ac.jp [Quantum Energy Applications, Department of Mechanical Science and Engineering, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan); Endo, Satoru [Quantum Energy Applications, Department of Mechanical Science and Engineering, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan); Shinozaki, Kenji [Materials Joining Science and Engineering, Department of Mechanical Science and Engineering, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan); Fukushima, Hiroshi [Materials Physics, Department of Mechanical Science and Engineering, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan)

    2013-05-01

    Fast neutron activation data for {sup 63}Ni in copper samples exposed to the Hiroshima atomic bomb are important in evaluating neutron doses to the survivors. Up to until now, accelerator mass spectrometry and liquid scintillation counting methods have been applied in {sup 63}Ni measurements and data were accumulated within 1500 m from the hypocenter. The slope of the activation curve versus distance shows reasonable agreement with the calculation result, however, data near the hypocenter are scarce. In the present work, two copper samples obtained from the Atomic bomb dome (155 m from the hypocenter) and the Bank of Japan building (392 m) were utilized in {sup 63}Ni beta-ray measurement with a Si surface barrier detector. Additionally, microscopic observation of the metal surfaces was performed for the first time. Only upper limit of {sup 63}Ni production was obtained for copper sample of the Atomic bomb dome. The result of the {sup 63}Ni measurement for Bank of Japan building show reasonable agreement with the AMS measurement and to fast neutron activation calculations based on the Dosimetry System 2002 (DS02) neutrons.

  3. Sample handling and chemical procedures for efficacious trace analysis of urine by neutron activation analysis

    International Nuclear Information System (INIS)

    Blotcky, A.J.; Rack, E.P.; Roman, F.R.

    1988-01-01

    Important for the determination of trace elements, ions, or compounds in urine by chemical neutron activation analysis is the optimization of sample handling, preirradiation chemistry, and radioassay procedures necessary for viable analysis. Each element, because of its natural abundance in the earth's crust and, hence, its potential for reagent and environmental contamination, requires specific procedures for storage, handling, and preirradiation chemistry. Radioassay techniques for radionuclides vary depending on their half-lives and decay characteristics. Described in this paper are optimized procedures for aluminum and selenium. While 28 Al (T 1/2 = 2.24 min) and 77m Se(T 1/2 = 17.4s) have short half-lives, their gamma-ray spectra are quite different. Aluminum-28 decays by a 1779-keV gamma and 77m Se by a 162-keV gamma. Unlike selenium, aluminum is a ubiquitous element in the environment requiring special handling to minimize contamination in all phases of its analytical determination

  4. The determination of chromium in water samples by neutron activation analysis after preconcentration on activated carbon

    International Nuclear Information System (INIS)

    Sloot, H.A. van der

    1977-01-01

    A method is presented for the determination of chromium in sea- and fresh water. Chromium is concentrated on activated carbon from a neutral solution after a previous reduction of chromate with sodium sulfite at pH 1.5. The adsorption conditions, acidity, concentrations, amount of carbon, stirring-time, sample-volume, salinity, the influence of storage on the ratio of tervalent to hexavalent chromium, were investigated. The final determination of the total chromium content is performed by instrumental neutron-activation analysis. By preconcentration on activated carbon, a differentiation between tervalent and hexavalent chromium is possible. A separate determination of both species is not yet feasible due to the high carbon blank and to the necessity of measuring the adsorption percentage on carbon. The lower limit of determination, which depends on the value of the carbon blank, is 0.05 μg Cr/l with a precision of 20%. The determination is hampered by the considerable blank from the carbon. The use of activated carbon prepared from recrystallized sugar will probably improve the lower limit of determination and possibly allow the determination of chromate. (T.G.)

  5. Study of organohalogens in foodstuffs and environmental samples by neutron activation analysis and related techniques

    International Nuclear Information System (INIS)

    Xu, D. D.; Mao, X.Y.; Ouyang, H.; Chai, Z. F.; Zhang, H.; Sun, H. B.

    2004-01-01

    Pine needles and foodstuffs collected from Beijing, China, were analyzed by instrumental neutron activation analysis (INAA) combined with organic solvent extraction for total halogens, extractable organohalogens (EOX) and extractable persistent organohalogens (EPOX). The INAA detection limits are 50 ng, 8 ng and 3.5 ng for Cl, Br and I, respectively. The contents and distribution patterns of organohalogens in these samples are reported. EOCl accounted for 0.013-0.016% and 1.6-2.7% of the total chlorine in yogurt and apples, respectively, which suggested that chlorine in foodstuffs mainly existed as inorganic species and non-extractable organochlorines. EOCl contents in pine needles and foodstuffs were noticeably higher than those of EOBr and EOI. For pine needles, yogurt and apples, 1.6-34%, 23-58% and 29-35% of EOCl remained as extractable persistent organochlorine (EPOCl), respectively. Pine needle containing higher EOCl contents in chemical industrial and traffic hub areas indicated that chemical industries and exhaust emission from vehicle were the main sources of organochlorines in the Beijing's air. The relative proportions of the known organochlorines (such as HCHs, DDTs, chlordanes, heptachlor, HCB and PCBs) to the total EOCl and EPOCl were 0.04-1.6% and 0.7-21.5%, respectively, which implied that the identity of species of a major portion of the EOCl and EPOCl measured in pine needles was unknown. (author)

  6. Determination of chromium in water samples by neutron activation analysis after preconcentration on activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    van der Sloot, H A [Stichting Reactor Centrum Nederland, Petten

    1977-01-01

    A method is presented for the determination of chromium in sea- and fresh water. Chromium is concentrated on activated carbon from a neutral solution after a previous reduction of chromate with sodium sulfite at pH 1.5. The adsorption conditions, acidity, concentrations, amount of carbon, stirring-time, sample-volume, salinity, the influence of storage on the ratio of tervalent to hexavalent chromium, were investigated. The final determination of the total chromium content is performed by instrumental neutron-activation analysis. By preconcentration on activated carbon, a differentiation between tervalent and hexavalent chromium is possible. A separate determination of both species is not yet feasible due to the high carbon blank and to the necessity of measuring the adsorption percentage on carbon. The lower limit of determination, which depends on the value of the carbon blank, is 0.05 ..mu..g Cr/l with a precision of 20%. The determination is hampered by the considerable blank from the carbon. The use of activated carbon prepared from recrystallized sugar will probably improve the lower limit of determination and possibly allow the determination of chromate.

  7. Method to determine trace elements in water samples by neutron activation analysis

    International Nuclear Information System (INIS)

    Kueppers, G.; Erdtmann, G.

    1981-05-01

    For the determination of trace elements in water by neutron activation analysis irradiation porcedures and chemical separation procedures have been developed. Irradiation in melted quarz glass ampoules in the presence of a platinum wire (for recombination of the oxyhydrogen gas produced by radiolysis) proved successfull with different variants of the irradiation methods, as long irradiation periods without pressure build-up could be achieved. Possible falsifications of the analysis results were investigated in detail (losses by absorption on vessel walls etc.). The irradiated samples can be measured directly with a gamma ray spectrometer and from the radionuclides found the trace element contents may be calculated. More sensitive determinations are possible if the radionuclides are chemically separated. Procedures for removing the matrix activities, for the separation of the radionuclides in groups of elements and for the isolation of single elements have been developed. For especially sensitive determination of some elements selective separation procedures for antimony, cadmium, selenium, mercury and uranium have been developed. The analytical procedures described have been applied to trace element determinations in river water, glacier ice and water solutions from technical processes. (orig./RB) [de

  8. Study of sampling rate influence on neutron-gamma discrimination with stilbene coupled to a silicon photomultiplier.

    Science.gov (United States)

    Zhang, Jinglong; Moore, Michael E; Wang, Zhonghai; Rong, Zhou; Yang, Chaowen; Hayward, Jason P

    2017-10-01

    Choosing a digitizer with an appropriate sampling rate is often a trade-off between performance and economy. The influence of sampling rates on the neutron-gamma Pulse Shape Discrimination (PSD) with a solid stilbene scintillator coupled to a Silicon Photomultiplier was investigated in this work. Sampling rates from 125MSPS to 2GSPS from a 10-bit digitizer were used to collect detector pulses produced by the interactions of a Cf-252 source. Due to the decreased signal-to-noise ratio (SNR), the PSD performance degraded with reduced sampling rates. The reason of PSD performance degradation was discussed. Then, an efficient combination of filtering and digital signal processing (DSP) was then applied to suppress the timing noise and electronic background noise. The results demonstrate an improved PSD performance especially at low sampling rates, down to 125MSPS. Using filtering and DSP, the ascribed Figure of Merit (FOM) at 125keV ee (± 10keV ee ) increased from 0.95 to 1.02 at 125MSPS. At 300keV ee and above, all the FOMs are better than 2.00. Our study suggests that 250MSPS is a good enough sampling rate for neutron-gamma discrimination in this system in order to be sensitive to neutrons at and above ~ 125keV ee . Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Discovery and identification of a series of alkyl decalin isomers in petroleum geological samples.

    Science.gov (United States)

    Wang, Huitong; Zhang, Shuichang; Weng, Na; Zhang, Bin; Zhu, Guangyou; Liu, Lingyan

    2015-07-07

    The comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/TOFMS) has been used to characterize a crude oil and a source rock extract sample. During the process, a series of pairwise components between monocyclic alkanes and mono-aromatics have been discovered. After tentative assignments of decahydronaphthalene isomers, a series of alkyl decalin isomers have been synthesized and used for identification and validation of these petroleum compounds. From both the MS and chromatography information, these pairwise compounds were identified as 2-alkyl-decahydronaphthalenes and 1-alkyl-decahydronaphthalenes. The polarity of 1-alkyl-decahydronaphthalenes was stronger. Their long chain alkyl substituent groups may be due to bacterial transformation or different oil cracking events. This systematic profiling of alkyl-decahydronaphthalene isomers provides further understanding and recognition of these potential petroleum biomarkers.

  10. Mare Crisium - Regional stratigraphy and geologic history. [from spectral reflectivities of Lunik 24 samples

    Science.gov (United States)

    Adams, J. B.; Head, J. W., III; Mccord, T. B.; Pieters, C.; Zisk, S.

    1978-01-01

    Spectral reflectance measurements of five Luna 24 samples and new telescopic reflectance spectra of 10-20 km areas of seven sites in Mare Crisium have been used to calibrate multispectral images of mare units. Based on these data, three major mare units are defined in the Crisium basin and their stratigraphy is interpreted. The oldest mare unit is exposed in the ejecta of the craters Picard and Peirce and along the outer edge of the southeastern part of the basin. The next younger unit includes the Luna 24 site and generally follows a topographic annulus along the basin margin. The youngest mare unit occupies the central part of the basin. It is concluded that subsidence occurred throughout the emplacement of mare units, including extensive warping and downfaulting of the inner part of the Crisium basin.

  11. Evaluation of precision and accuracy of neutron activation analysis method of environmental samples analysis

    International Nuclear Information System (INIS)

    Wardani, Sri; Rina M, Th.; L, Dyah

    2000-01-01

    Evaluation of precision and accuracy of Neutron Activation Analysis (NAA) method used by P2TRR performed by analyzed the standard reference samples from the National Institute of Environmental Study of Japan (NIES-CRM No.10 (rice flour) and the National Bureau of USA (NBS-SRM 1573a (tomato leave) by NAA method. In analyze the environmental SRM No.10 by NAA method in qualitatively could identified multi elements of contents, namely: Br, Ca, Co, CI, Cs, Gd, I, K< La, Mg, Mn, Na, Pa, Sb, Sm, Sr, Ta, Th, and Zn (19 elements) for SRM 1573a; As, Br, Cr, CI, Ce, Co, Cs, Fe, Ga, Hg, K, Mn, Mg, Mo, Na, Ni, Pb, Rb, Sr, Se, Sc, Sb, Ti, and Zn, (25 elements) for CRM No.10a; Ag, As, Br, Cr, CI, Ce, Cd, Co, Cs, Eu, Fe, Ga, Hg, K, Mg, Mn, Mo, Na, Nb, Pb, Rb, Sb, Sc, Th, TI, and Zn, (26 elements) for CRM No. 10b; As, Br, Co, CI, Ce, Cd, Ga, Hg, K, Mn, Mg, Mo, Na, Nb, Pb, Rb, Sb, Se, TI, and Zn (20 elementary) for CRM No.10c. In the quantitatively analysis could determined only some element of sample contents, namely: As, Co, Cd, Mo, Mn, and Zn. From the result compared with NIES or NBS values attained with deviation of 3% ∼ 15%. Overall, the result shown that the method and facilities have a good capability, but the irradiation facility and the software of spectrometry gamma ray necessary to developing or seriously research perform

  12. Sampling and analytical methodologies for instrumental neutron activation analysis of airborne particulate matter

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-01

    The IAEA supports a number of projects having to do with the analysis of airborne particulate matter by nuclear techniques. Most of this work involves the use of activation analysis in its various forms, particularly instrumental neutron activation analysis (INAA). This technique has been widely used in many different countries for the analysis of airborne particulate matter, and there are already many publications in scientific journals, books and reports describing such work. The present document represents an attempt to summarize the most important features of INAA as applied to the analysis of airborne particulate matter. It is intended to serve as a set of guidelines for use by participants in the IAEA's own programmes, and other scientists, who are not yet fully experienced in the application of INAA to airborne particulate samples, and who wish either to make a start on using this technique or to improve their existing procedures. The methodologies for sampling described in this document are of rather general applicability, although they are presented here in a way that takes account of the particular requirements arising from the use of INAA as the analytical technique. The analytical part of the document, however, is presented in a form that is applicable only to INAA. (Subsequent publications in this series are expected to deal specifically with other nuclear related techniques such as energy dispersive X ray fluorescence (ED-XRF) and particle induced X ray emission (PIXE) analysis). Although the methods and procedures described here have been found through experience to yield acceptable results, they should not be considered mandatory. Any other procedure used should, however, be chosen to be capable of yielding results at least of equal quality to those described.

  13. Sampling and analytical methodologies for instrumental neutron activation analysis of airborne particulate matter

    International Nuclear Information System (INIS)

    1992-01-01

    The IAEA supports a number of projects having to do with the analysis of airborne particulate matter by nuclear techniques. Most of this work involves the use of activation analysis in its various forms, particularly instrumental neutron activation analysis (INAA). This technique has been widely used in many different countries for the analysis of airborne particulate matter, and there are already many publications in scientific journals, books and reports describing such work. The present document represents an attempt to summarize the most important features of INAA as applied to the analysis of airborne particulate matter. It is intended to serve as a set of guidelines for use by participants in the IAEA's own programmes, and other scientists, who are not yet fully experienced in the application of INAA to airborne particulate samples, and who wish either to make a start on using this technique or to improve their existing procedures. The methodologies for sampling described in this document are of rather general applicability, although they are presented here in a way that takes account of the particular requirements arising from the use of INAA as the analytical technique. The analytical part of the document, however, is presented in a form that is applicable only to INAA. (Subsequent publications in this series are expected to deal specifically with other nuclear related techniques such as energy dispersive X ray fluorescence (ED-XRF) and particle induced X ray emission (PIXE) analysis). Although the methods and procedures described here have been found through experience to yield acceptable results, they should not be considered mandatory. Any other procedure used should, however, be chosen to be capable of yielding results at least of equal quality to those described

  14. Instrumental neutron activation analysis of some fossil samples from Romanian palaeolontologic sites

    International Nuclear Information System (INIS)

    Pantelica, A. I.; Salagean, M. N.; Scarlat, A. G.; Georgescu, I. I.; Murariu-Magureanu, M.D

    2001-01-01

    During the fossilization process, elemental contents of the buried materials are modified by different physical, chemical and biological factors, such as ground water flow and degree of aeration, chemical composition of the soil, bacterial activity, the process being influenced by the climatical conditions. Bone tissue, by the calcium phosphate mineral (hydroxyapatite) in the external part and organic component (fat and collagen) in the inner part, has proved to be a proper substrate for minor elements accumulation. The uniform increasing of certain elemental concentrations during the fossilization process is generally used in palaeoscience for the age dating. Instrumental neutron activation analysis (INAA) method was used by us to determine Al, As, Au, Ba, Br, Ca, Co, Cr, Cs, Fe, Hf, K, Mg, Mn, Na, Ni, Rb, Sb, Sc, Se, Sr, Th, U, V, Zn, and of the rare earth elements Ce, Eu, La, Lu, Nd, Sm, Tb, Yb contents of two different fossil materials discovered in Romania during 1995-1996: Elephas primigenius mammoth mandible bone (1.5-2 million years age) and Pecten solarium shell (20-25 million years age). Mammoth mandible bone samples were taken both from the external and the internal part of the bone. Shell fragments were taken in association with the surrounding rock samples. Irradiations were carried out at the WWR-S reactor in Bucharest (neutron fluence rate 2.3 x 10 12 cm -2 s -1 and at the TRIGA reactor in Pitesti (neutron fluence rate 5 x 10 13 cm -2 s -1 . For the mammoth mandible bone (relative high contents of U and P) corrections were done for the uranium fission and (n,γ)β - contribution to Ce, La, Nd and Sm concentrations, and for the phosphorus interference in Al determination. It was taken into account that 141 Ce, 140 La, 147 Nd, 153 Sm isotopes are originated not only by the neutron activation reactions of these elements, but also from the beta - decay chains of the uranium fission products; for 153 Sm, spectral interference with 103.65 keV X-ray of 239

  15. Determination of Mercury in Aqueous Samples by Means of Neutron Activation Analysis with an Account of Flux Disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D; Jirlow, K

    1967-08-15

    The technique of low temperature neutron irradiation combined with isotopic exchange separation technique has been applied in the determination of mercury in aqueous samples. The kinetics of the isotopic exchange reaction has been studied for various sample volumes. The effect of the flux perturbation caused by aqueous samples has been investigated for samples of various size and geometry in a central position in a well moderated heavy water reactor. The effect has been studied both theoretically and experimentally. The 'Thermos' code has been used in the calculations.

  16. Determination of Mercury in Aqueous Samples by Means of Neutron Activation Analysis with an Account of Flux Disturbances

    International Nuclear Information System (INIS)

    Brune, D.; Jirlow, K.

    1967-08-01

    The technique of low temperature neutron irradiation combined with isotopic exchange separation technique has been applied in the determination of mercury in aqueous samples. The kinetics of the isotopic exchange reaction has been studied for various sample volumes. The effect of the flux perturbation caused by aqueous samples has been investigated for samples of various size and geometry in a central position in a well moderated heavy water reactor. The effect has been studied both theoretically and experimentally. The 'Thermos' code has been used in the calculations

  17. Multi-phase classification by a least-squares support vector machine approach in tomography images of geological samples

    Science.gov (United States)

    Khan, Faisal; Enzmann, Frieder; Kersten, Michael

    2016-03-01

    Image processing of X-ray-computed polychromatic cone-beam micro-tomography (μXCT) data of geological samples mainly involves artefact reduction and phase segmentation. For the former, the main beam-hardening (BH) artefact is removed by applying a best-fit quadratic surface algorithm to a given image data set (reconstructed slice), which minimizes the BH offsets of the attenuation data points from that surface. A Matlab code for this approach is provided in the Appendix. The final BH-corrected image is extracted from the residual data or from the difference between the surface elevation values and the original grey-scale values. For the segmentation, we propose a novel least-squares support vector machine (LS-SVM, an algorithm for pixel-based multi-phase classification) approach. A receiver operating characteristic (ROC) analysis was performed on BH-corrected and uncorrected samples to show that BH correction is in fact an important prerequisite for accurate multi-phase classification. The combination of the two approaches was thus used to classify successfully three different more or less complex multi-phase rock core samples.

  18. A Comparison of Multivariate and Pre-Processing Methods for Quantitative Laser-Induced Breakdown Spectroscopy of Geologic Samples

    Science.gov (United States)

    Anderson, R. B.; Morris, R. V.; Clegg, S. M.; Bell, J. F., III; Humphries, S. D.; Wiens, R. C.

    2011-01-01

    The ChemCam instrument selected for the Curiosity rover is capable of remote laser-induced breakdown spectroscopy (LIBS).[1] We used a remote LIBS instrument similar to ChemCam to analyze 197 geologic slab samples and 32 pressed-powder geostandards. The slab samples are well-characterized and have been used to validate the calibration of previous instruments on Mars missions, including CRISM [2], OMEGA [3], the MER Pancam [4], Mini-TES [5], and Moessbauer [6] instruments and the Phoenix SSI [7]. The resulting dataset was used to compare multivariate methods for quantitative LIBS and to determine the effect of grain size on calculations. Three multivariate methods - partial least squares (PLS), multilayer perceptron artificial neural networks (MLP ANNs) and cascade correlation (CC) ANNs - were used to generate models and extract the quantitative composition of unknown samples. PLS can be used to predict one element (PLS1) or multiple elements (PLS2) at a time, as can the neural network methods. Although MLP and CC ANNs were successful in some cases, PLS generally produced the most accurate and precise results.

  19. Measure the constituents of geological samples by XRF intensity influence coefficient method

    International Nuclear Information System (INIS)

    Dai Zhenlin; Ge Liangquan; Cheng Feng; Zhang Qingxian

    2008-01-01

    The elements of some ore samples (including primary ores in the mine) have been measured by using the Si-PIN detector and the portable high energy resolution XRF analyzer with an embedded computer constituting the intensity correction model of influence coefficient method. By comparing to the result by chemical analysis, the conclusion could be made as follows: the maximal relative error of the content of the element Fe with the content between 20% to 55% is not more than 4.74%, the maximal relative error of the content of the element Cu with the content between 182ppm to 2400ppm is not more than 24. 70% and not more than 7.46% with the content between 2400ppm to 3600ppm, the maximal relative error of the content of the element Zn with the content between 556ppm to 3200ppm is not more than 25. 93% and not more than 4.74% with the content between 3200ppm to 21600ppm, the maximal relative error of the content of the element Pb with the content between 5900ppm to 204200ppm is not more than 23.80% and not more than 13.79% with the content between 204200ppm to 511200ppm. In this way, this model could overcome the influence of matrix effect from base material components commendably and guide the work of mineral beneficiation in the mine effectively. (authors)

  20. Measurement and calculation of neutron leakage spectra from slab samples of beryllium, gallium and tungsten irradiated with 14.8 MeV neutrons

    Science.gov (United States)

    Nie, Y. B.; Ruan, X. C.; Ren, J.; Zhang, S.; Han, R.; Bao, J.; Huang, H. X.; Ding, Y. Y.; Wu, H. C.; Liu, P.; Zhou, Z. Y.

    2017-09-01

    In order to make benchmark validation of the nuclear data for gallium (Ga), tungsten (W) and beryllium (Be) in existing modern evaluated nuclear data files, neutron leakage spectra in the range from 0.8 to 15 MeV from slab samples were measured by time-of-flight technique with a BC501 scintillation detector. The measurements were performed at China Institute of Atomic Energy (CIAE) using a D-T neutron source. The thicknesses of the slabs were 0.5 to 2.5 mean free path for 14.8 MeV neutrons, and the measured angles were chosen to be 60∘ and 120∘. The measured spectra were compared with those calculated by the continuous energy Monte-Carlo transport code MCNP, using the data from the CENDL-3.1, ENDF/B-VII.1 and JENDL-4.0 nuclear data files, the comparison between the experimental and calculated results show that: The results from all three libraries significantly underestimate the cross section in energy range of 10-13 MeV for Ga; For W, the calculated spectra using data from CENDL-3.1 and JENDL-4.0 libraries show larger discrepancies with the measured ones, especially around 8.5-13.5 MeV; and for Be, all the libraries led to underestimation below 3 MeV at 120∘.

  1. Use of CITATION code for flux calculation in neutron activation analysis with voluminous sample using an Am-Be source

    International Nuclear Information System (INIS)

    Khelifi, R.; Idiri, Z.; Bode, P.

    2002-01-01

    The CITATION code based on neutron diffusion theory was used for flux calculations inside voluminous samples in prompt gamma activation analysis with an isotopic neutron source (Am-Be). The code uses specific parameters related to the energy spectrum source and irradiation system materials (shielding, reflector). The flux distribution (thermal and fast) was calculated in the three-dimensional geometry for the system: air, polyethylene and water cuboidal sample (50x50x50 cm). Thermal flux was calculated in a series of points inside the sample. The results agreed reasonably well with observed values. The maximum thermal flux was observed at a distance of 3.2 cm while CITATION gave 3.7 cm. Beyond a depth of 7.2 cm, the thermal flux to fast flux ratio increases up to twice and allows us to optimise the detection system position in the scope of in-situ PGAA

  2. Materials and Life Science Experimental Facility at the Japan Proton Accelerator Research Complex III: Neutron Devices and Computational and Sample Environments

    Directory of Open Access Journals (Sweden)

    Kaoru Sakasai

    2017-08-01

    Full Text Available Neutron devices such as neutron detectors, optical devices including supermirror devices and 3He neutron spin filters, and choppers are successfully developed and installed at the Materials Life Science Facility (MLF of the Japan Proton Accelerator Research Complex (J-PARC, Tokai, Japan. Four software components of MLF computational environment, instrument control, data acquisition, data analysis, and a database, have been developed and equipped at MLF. MLF also provides a wide variety of sample environment options including high and low temperatures, high magnetic fields, and high pressures. This paper describes the current status of neutron devices, computational and sample environments at MLF.

  3. Preparing Monodisperse Macromolecular Samples for Successful Biological Small-Angle X-ray and Neutron Scattering Experiments

    Science.gov (United States)

    Jeffries, Cy M.; Graewert, Melissa A.; Blanchet, Clément E.; Langley, David B.; Whitten, Andrew E.; Svergun, Dmitri I

    2017-01-01

    Small-angle X-ray and neutron scattering (SAXS and SANS) are techniques used to extract structural parameters and determine the overall structures and shapes of biological macromolecules, complexes and assemblies in solution. The scattering intensities measured from a sample contain contributions from all atoms within the illuminated sample volume including the solvent and buffer components as well as the macromolecules of interest. In order to obtain structural information, it is essential to prepare an exactly matched solvent blank so that background scattering contributions can be accurately subtracted from the sample scattering to obtain the net scattering from the macromolecules in the sample. In addition, sample heterogeneity caused by contaminants, aggregates, mismatched solvents, radiation damage or other factors can severely influence and complicate data analysis so it is essential that the samples are pure and monodisperse for the duration of the experiment. This Protocol outlines the basic physics of SAXS and SANS and reveals how the underlying conceptual principles of the techniques ultimately ‘translate’ into practical laboratory guidance for the production of samples of sufficiently high quality for scattering experiments. The procedure describes how to prepare and characterize protein and nucleic acid samples for both SAXS and SANS using gel electrophoresis, size exclusion chromatography and light scattering. Also included are procedures specific to X-rays (in-line size exclusion chromatography SAXS) and neutrons, specifically preparing samples for contrast matching/variation experiments and deuterium labeling of proteins. PMID:27711050

  4. A New On-the-Fly Sampling Method for Incoherent Inelastic Thermal Neutron Scattering Data in MCNP6

    Energy Technology Data Exchange (ETDEWEB)

    Pavlou, Andrew Theodore [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ji, Wei [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2014-09-02

    At thermal energies, the scattering of neutrons in a system is complicated by the comparable velocities of the neutron and target, resulting in competing upscattering and downscattering events. The neutron wavelength is also similar in size to the target's interatomic spacing making the scattering process a quantum mechanical problem. Because of the complicated nature of scattering at low energies, the thermal data files in ACE format used in continuous-energy Monte Carlo codes are quite large { on the order of megabytes for a single temperature and material. In this paper, a new storage and sampling method is introduced that is orders of magnitude less in size and is used to sample scattering parameters at any temperature on-the-fly. In addition to the reduction in storage, the need to pre-generate thermal scattering data tables at fine temperatures has been eliminated. This is advantageous for multiphysics simulations which may involve temperatures not known in advance. A new module was written for MCNP6 that bypasses the current S(α,β) table lookup in favor of the new format. The new on-the-fly sampling method was tested for graphite for two benchmark problems at ten temperatures: 1) an eigenvalue test with a fuel compact of uranium oxycarbide fuel homogenized into a graphite matrix, 2) a surface current test with a \\broomstick" problem with a monoenergetic point source. The largest eigenvalue difference was 152pcm for T= 1200K. For the temperatures and incident energies chosen for the broomstick problem, the secondary neutron spectrum showed good agreement with the traditional S(α,β) sampling method. These preliminary results show that sampling thermal scattering data on-the-fly is a viable option to eliminate both the storage burden of keeping thermal data at discrete temperatures and the need to know temperatures before simulation runtime.

  5. Study the Possibility of measuring Heavy Metals Arising from Gold Mining Sample using 252Cf Neutron Source

    International Nuclear Information System (INIS)

    Soliman, N.F.

    2012-01-01

    Mining activities contribute immensely to trace element pollution .The present work studied the possibility of measuring heavy metals arising from gold mining areas Eastern Desert in Egypt using the isotopic 252 Cf neutron source. 38.5 g of the sample is irradiated in a neutron field of 252 Cf for 36.75 days and 0.3 mg of the sample is irradiated at the Pneumatic Irradiation Rabbit System (PIRS) built in the vertical thermal column of the ET-RR-2 reactor . The induced activities in the samples are measured using two high resolution f ray spectrometry systems (including two calibrated HPGe detectors). The kο standardization neutron activation analysis (kο-NAA) method was used to analyze the sample under investigation. Thermal to epithermal flux ratio fat the two irradiation positions are measured. The obtained results indicated that the values of the suspected heavy metals such as sodium, magnesium, potassium, manganese, arsenic, ruthenium and tantalum were higher than the background values, signifying accumulation of these heavy metals due to gold mining activities .The accuracy and precision of the method has been evaluated

  6. Sample registration software for process automation in the Neutron Activation Analysis (NAA) Facility in Malaysia nuclear agency

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Nur Aira Abd, E-mail: nur-aira@nuclearmalaysia.gov.my; Yussup, Nolida; Ibrahim, Maslina Bt. Mohd; Mokhtar, Mukhlis B.; Soh Shaari, Syirrazie Bin Che; Azman, Azraf B. [Technical Support Division, Malaysian Nuclear Agency, 43000, Kajang, Selangor (Malaysia); Salim, Nazaratul Ashifa Bt. Abdullah [Division of Waste and Environmental Technology, Malaysian Nuclear Agency, 43000, Kajang, Selangor (Malaysia); Ismail, Nadiah Binti [Fakulti Kejuruteraan Elektrik, UiTM Pulau Pinang, 13500 Permatang Pauh, Pulau Pinang (Malaysia)

    2015-04-29

    Neutron Activation Analysis (NAA) had been established in Nuclear Malaysia since 1980s. Most of the procedures established were done manually including sample registration. The samples were recorded manually in a logbook and given ID number. Then all samples, standards, SRM and blank were recorded on the irradiation vial and several forms prior to irradiation. These manual procedures carried out by the NAA laboratory personnel were time consuming and not efficient. Sample registration software is developed as part of IAEA/CRP project on ‘Development of Process Automation in the Neutron Activation Analysis (NAA) Facility in Malaysia Nuclear Agency (RC17399)’. The objective of the project is to create a pc-based data entry software during sample preparation stage. This is an effective method to replace redundant manual data entries that needs to be completed by laboratory personnel. The software developed will automatically generate sample code for each sample in one batch, create printable registration forms for administration purpose, and store selected parameters that will be passed to sample analysis program. The software is developed by using National Instruments Labview 8.6.

  7. Sample registration software for process automation in the Neutron Activation Analysis (NAA) Facility in Malaysia nuclear agency

    Science.gov (United States)

    Rahman, Nur Aira Abd; Yussup, Nolida; Salim, Nazaratul Ashifa Bt. Abdullah; Ibrahim, Maslina Bt. Mohd; Mokhtar, Mukhlis B.; Soh@Shaari, Syirrazie Bin Che; Azman, Azraf B.; Ismail, Nadiah Binti

    2015-04-01

    Neutron Activation Analysis (NAA) had been established in Nuclear Malaysia since 1980s. Most of the procedures established were done manually including sample registration. The samples were recorded manually in a logbook and given ID number. Then all samples, standards, SRM and blank were recorded on the irradiation vial and several forms prior to irradiation. These manual procedures carried out by the NAA laboratory personnel were time consuming and not efficient. Sample registration software is developed as part of IAEA/CRP project on `Development of Process Automation in the Neutron Activation Analysis (NAA) Facility in Malaysia Nuclear Agency (RC17399)'. The objective of the project is to create a pc-based data entry software during sample preparation stage. This is an effective method to replace redundant manual data entries that needs to be completed by laboratory personnel. The software developed will automatically generate sample code for each sample in one batch, create printable registration forms for administration purpose, and store selected parameters that will be passed to sample analysis program. The software is developed by using National Instruments Labview 8.6.

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  9. Elemental analysis in bed sediment samples of Karnafuli estuarine zone in the Bay of Bengal by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Molla, N.I.; Hossain, S.M.; Basunia, S.; Miah, R.U.; Rahman, M.; Sikder, D.H.; Chowdhury, M.I.

    1997-01-01

    The concentration of rare earths and other elements have been determined in the bed sediment samples of Karnafuli estuarine zone in the Bay of Bengal by instrumental neutron activation analysis (INAA). The samples and the standards soil-5, soil-7, coal fly ash and pond sediment were prepared and simultaneously irradiated for short and long time at the TRIGA Mark-II research reactor facility of Atomic Energy Research Establishment, Savar, Dhaka. The maximum thermal neutron flux was of the order of 10 13 n x cm -2 x s -1 . After irradiation the radioactivity of the product nuclides was measured by using a high resolution high purity germanium detector system. Analysis of γ-ray spectra and quantitative analysis of the elemental concentration were done via the software GANAAS. It has been possible to determine the concentration level of 27 elements including the rare earths La, Ce, Sm, Eu, Tb, Dy and Yb and uranium and thorium. (author)

  10. Neutron radiographic testing of samples of special concrete containing recycled PET granules as aggregate

    International Nuclear Information System (INIS)

    Moraes, Antonio Carlos Alves de; Crispim, Verginia Reis

    2011-01-01

    This study aimed at inspecting microcracks in test specimens of special concrete, through neutron radiography tests. The thermal neutron flux used was extracted from the J-9 irradiation channel, placed in the thermal column of Argonauta/IEN/CNEN/RJ reactor, where a neutron radiographic system is installed. The test specimens inspected were molded in a cylindrical shape, with standard concrete and modified concrete where coarse sand was substituted by granules of recycled PET. They were submitted to compression in a SHIMADSU UH F 1000 press, causing microcracks. Then, slices of 50 μm thickness were obtained using an electrical saw. Gadolinium nitrate was used as contrast liquid in order to enhance the visualization of those microcracks. The Neutron Radiography technique proved to be appropriate for this kind of inspection, allowing to clearly visualizing the microcracks. Recycled PET granules met ABNT standards, and may be used in the construction of low income people houses, as structural concrete (25 % PP) or house floors (25% to 50% PEAD). The mechanical properties of compression and elasticity demonstrated for this special concrete, on Civil Engineering conventional tests, and by the neutron radiographic images obtained, showed that its use is viable even for civil construction in areas subject to seismic vents. (author)

  11. Study on the application of crown ether for neutron activation analysis of rubidium and rhenium in rock samples

    International Nuclear Information System (INIS)

    Wang Xiaolin; Fu Yibei; Liu Yinong; Xiong Zonghua; Hao Fanhua

    1996-01-01

    The extraction behaviour of rubidium and rhenium with 18-crown-6 (18C6) and benzo-15-crown-5 (B15C5) in nitrobenzene from picric acid or potassium hydroxide solution are studied and methods for separation and determination are developed. The molar ratio of 18C6 to Rb and B15C5 to Re in the extracted species is probably 2:1. Rubidium and rhenium in rock samples are satisfactorily determined by neutron activation method

  12. New experimental space for irradiating samples by RA reactor fast neutron flux at temperatures up to 100 deg C

    International Nuclear Information System (INIS)

    Pavicevic, M.; Novakovic, M.; Zecevic, V.

    1961-01-01

    The objective of this paper is to present adaptation of the RA reactor which would enable samples irradiation by fast neutrons and describe new experimental possibilities. New experimental space was achieved using hollow fuel elements which have been reconstructed to enable placement of irradiation capsules inside the tube. This paper includes thermal analysis and describes problems related to operation, safety and radiation protection issues which arise from using reconstructed fuel elements

  13. Analysis of some egyptian cosmetic samples by using fast neutron activation analysis

    International Nuclear Information System (INIS)

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

    2002-01-01

    A description of our neutron generator (NG) facility for neutron activation analysis is presented. As an example, the concentration of Na, Mg, Al, Si, K, Cl, Ca and Fe elements were determined in two domestic brands of face powder by using a beam of 14 MeV neutrons. An empirical expression for detector efficiency in terms of incident gamma ray energy and the source-detector distance has been obtained for a hyper pure germanium detector (HPGe) using different standard point sources. The comparison of the calculated efficiencies and the measured values in the energy range from 59.5 to 1332.2 keV and for source-to-detector distances of 5-30 cm show the agreement between the calculated values and the measured experimental values

  14. Re-evaluation and extension of the scope of elements in US Geological Survey Standard Reference Water Samples

    Science.gov (United States)

    Peart, D.B.; Antweiler, Ronald C.; Taylor, Howard E.; Roth, D.A.; Brinton, T.I.

    1998-01-01

    More than 100 US Geological Survey (USGS) Standard Reference Water Samples (SRWSs) were analyzed for numerous trace constituents, including Al, As, B, Ba, Be, Bi, Br, Cd, Cr, Co, Cu, I, Fe, Pb, Li, Mn, Mo, Ni, Rb, Sb, Se, Sr, Te, Tl, U, V, Zn and major elements (Ca, Mg, Na, SiO2, SO4, Cl) by inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry. In addition, 15 USGS SRWSs and National Institute of Standards and Technology (NIST) standard reference material (SRM) 1641b were analyzed for mercury using cold vapor atomic fluorescence spectrometry. Also USGS SRWS Hg-7 was analyzed using isotope dilution-inductively coupled plasma mass spectrometry. The results were compared with the reported certified values of the following standard reference materials: NIST SRM 1643a, 1643b, 1643c and 1643d and National Research Council of Canada Riverine Water Reference Materials for Trace Metals SLRS-1, SLRS-2 and SLRS-3. New concentration values for trace and major elements in the SRWSs, traceable to the certified standards, are reported. Additional concentration values are reported for elements that were neither previously published for the SRWSs nor traceable to the certified reference materials. Robust statistical procedures were used that were insensitive to outliers. These data can be used for quality assurance/quality control purposes in analytical laboratories.

  15. Determination of Oxygen in Aluminum by Means of 14 MeV Neutrons with an Account of Flux Attenuation in the Sample

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D; Jirlow, K

    1967-11-15

    This study concerns the determination of oxygen present at low levels in aluminum using the 14 MeV neutron activation technique. The sensitivity obtained amounted to 0.2 mg oxygen. Various nuclear methods for the oxygen determination have been briefly reviewed. The attenuation of fast neutrons inside the aluminum samples has been calculated.

  16. Ir and Rare Earth's Elements determination by Neutron Activation Analysis and ICP - MS in soil samples

    Science.gov (United States)

    Salvini, A.; Cattadori, C.; Broggini, C.; Cagnazzo, M.; Ori, Gian Gabriele; Nisi, S.; Borio, A.; Manera, S.

    2006-05-01

    The platinum metals depleted in the earth's crust are relative to their cosmic abundance; concentration of these elements in sediments may thus indicate influxes of extraterrestrial material. Analysis of these parameters are done easily by Neutron Activation Analysis (NAA) and comparative results with ICP-MS technique show a good match. Results, adjust parameters and limits of this method will be displayed in tables.

  17. Determination of the thermal neutron absorption cross section for rock samples by a single measurement of the time decay constant

    International Nuclear Information System (INIS)

    Krynicka, E.

    1993-01-01

    A calibration method for the determination of the thermal neutron macroscopic mass absorption cross section for rock samples is presented. The standard deviation of the final results is discussed in detail. A big advantage of the presented method is that the calibration curves have been found using the results obtained for a variety of natural rock samples of different stratigraphies and lithologies measured by Czubek's methods. An important part of the paper is a through analysis of the standard deviation of the final result. (author). 13 refs, 11 figs, 5 tabs

  18. Study on water-sediment interaction in samples from Rio das Velhas - Minas Gerais State - Brazil using instrumental neutron activation analysis, and argon plasma coupled mass spectroscopy

    International Nuclear Information System (INIS)

    Veado, Maria Adelaide R.V.; Oliveira, Arno H. de; Revel, G.; Pinte, G.; Toulhoat, P.

    1999-01-01

    Sorption of the metallic elements in aqueous solutions in surface of the hydroxides affects the transport of heavy elements in the freshwaters. Sorption and the chemistry of the hydroxides are important studies for knowledge in geology, waters and waste treatment, and environment studies. In the industrial mining region areas, the river surface waters are subject to modifications in its physical and chemistries properties: pH, DBO, conductivity and alkalinity. Instrumental neutron activation analysis and inductively coupled plasma-mass spectrometry (ICP-MS), have ben used for the determination of toxic heavy metals and others pollutants in the Das Velhas river in State of Minas Gerais, in south-east Brazil. Water samples were collected with acidification on site, which provoked a change of its natural pH. Consequently, metallic elements associated to hydroxides and to particles in suspension were liberated. The objective of this paper is to show the different behavior of any elements, in water of Das Velhas river, with relation of its chemical forms (cations or anions), the solubility degree, the pH and the presence of rare earth elements. (author)

  19. The state-of-the-art and prospects of the oxidation titration method for the determination of uranium in geological samples

    International Nuclear Information System (INIS)

    Sun Jiayan

    1986-01-01

    The state-of-the-art of the oxidation titration method for the determination of uranium in geological samples is reviewed in some respects such as the prereduction of U(VI), oxidation of U(IV) and the detection of the end-point. Comments are also made on the prospects of further improvements of this method

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

    International Nuclear Information System (INIS)

    Robinson, L.; Zhao, L.

    2009-01-01

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

  1. Determination of gold and silver in geological samples by focused infrared digestion: A re-investigation of aqua regia digestion.

    Science.gov (United States)

    Wang, Yong; Baker, Laura A; Brindle, Ian D

    2016-02-01

    Focused infrared radiation-based digestions, for the determination of gold and silver, can be achieved in a timeframe as short as 10-15 min, making it an attractive candidate technology for the mining industry, where very large numbers of samples are analyzed on a daily basis. An investigation was carried out into gold and silver dissolution chemistry from geological samples using this novel digestion technique. This study investigated in-depth the issue of low recoveries of gold from aqua regia (AR) digestions, reported by a number of researchers. Conventional AR digestions consistently delivered gold recoveries in a range of 69-80% of the certified values for the four certified reference materials (CRM) employed (CCU-1d, SN26, OREAS 62c, and AMiS 0274), while silver recoveries were satisfactory. By gradually shifting the HCl:HNO3 ratio (v/v) from 3:1 to a reversed 1:3 ratio, recoveries of gold and silver exhibited inverse trends. At a HCl:HNO3 ratio of 1:3, complete recovery of gold was achieved with excellent reproducibility in all CRMs. Meanwhile, silver recoveries plunged significantly at this ratio in samples with higher silver concentrations. Silver values were recovered, however, when the silver was re-solubilized by adding a small volume of concentrated HCl to the cooled reverse aqua regia digests. Recoveries of base metals, such as Fe and Cu, were satisfactory throughout and were much less sensitive to changes in the digestion medium. Using four CRMs and five real-world gold/silver containing samples, the utility of the proposed reverse aqua regia was systematically studied. The uncomplicated nature of the digestion methods reported here, that are fast, effective and inexpensive, may be useful to analysts developing/optimizing their methods for the rapid determination of Au and Ag in a variety of mineral phases, particularly where rapid results are desirable, such as in prospecting and mine development. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. A comparative examination of several techniques for the routine determination of mercury in biological samples by neutron activation analysis

    International Nuclear Information System (INIS)

    Faanhof, A.; Das, H.A.

    1978-01-01

    A comparative examination of the most important techniques for the separation of mercury from irradiated biological material was made. Procedures for routine analysis and results for standard materials are given. Activation was performed at a thermal neutron flux of approximately 5x10 12 nxcm -2 xs -1 during ( 3 ) 2 offers a convenient solution to this problem. The variation of the neutron flux with the irradiation position can be measured by the application of thin iron rings as flux monitors. Losses of mercury due to uptake in the wall of the irradiation containers are negligible. The most powerful destruction technique for large samples is that based on a stainless-steel bomb. (T. I.)

  3. A simple, rapid and eco friendly method for determination of uranium in geological samples of low silicate matrix by ICP-OES

    International Nuclear Information System (INIS)

    Hanuman, V.V.; Chakrapani, G.; Singh, A.K.

    2013-01-01

    A simple, rapid, cost effective and eco friendly decomposition and dissolution method is developed for the determination of uranium (U 3 O 8 ) by Inductively Coupled Plasma - Optical Emission Spectrometer (ICP-OES) in low silicate geological samples. The salts of Sodium di-hydrogen phosphate monohydrate and Sodium pyrophosphate deca hydrate are used in the ratio of 1:1 (phosphate flux) for the decomposition of low silicate matrix geological samples. Samples are decomposed by fusion with the phosphate flux after ignition and the dissolution is carried out using distilled water. If the samples contain >10% silica, they have been treated with little amount of (HF+HNO 3 ) prior to fusion with phosphate flux. These samples, are analysed by ICP-OES directly without any separation from the matrix. The spectral interferences of major matrix elements (Al, Ti, Fe, Mn, etc present in the sample) on uranium are studied and it is observed that their interferences are negligible, as dilution is required to bring uranium concentration into calibration range of instrument. This is the first time, the phosphate flux is used for decomposition of low silicate geological samples for uranium determination by ICP-OES

  4. Structural effects of C60+ bombardment on various natural mineral samples-Application to analysis of organic phases in geological samples

    International Nuclear Information System (INIS)

    Siljestroem, S.; Lausmaa, J.; Hode, T.; Sundin, M.; Sjoevall, P.

    2011-01-01

    by a thick layer of deposited carbon. Despite the appearance of the sputter-induced structures and carbon deposition, most oil-bearing inclusions could successfully be opened and analysed. However, smaller inclusion ( 60 , carbon deposition, topography, mineral, fluid inclusions, geological samples, depth profiling.

  5. Direct determination of platinum group elements and their distributions in geological and environmental samples at the ng g{sup -1} level using LA-ICP-IDMS

    Energy Technology Data Exchange (ETDEWEB)

    Boulyga, Sergei F.; Heumann, Klaus G. [Johannes Gutenberg-University Mainz, Institute of Inorganic Chemistry and Analytical Chemistry, Mainz (Germany)

    2005-10-01

    Laser ablation inductively coupled plasma isotope dilution mass spectrometry (LA-ICP-IDMS) was applied to the direct and simultaneous determination of the platinum group elements (PGEs) Pt, Pd, Ru, and Ir in geological and environmental samples. A special laser ablation system with high ablation rates was used, along with sector field ICP-MS. Special attention was paid to deriving the distributions of PGEs in the pulverized samples. IDMS could not be applied to the (mono-isotopic) Rh, but the similar ablation behavior of Ru and Rh allowed Rh to be simultaneously determined via relative sensitivity coefficients. The laser ablation process produces hardly any oxide ions (which usually cause interference in PGE analysis with liquid sample injection), so the ICP-MS can be run in its low mass resolution but high-sensitivity mode. The detection limits obtained for the geological samples were 0.16 ng g{sup -1}, 0.14 ng g{sup -1}, 0.08 ng g{sup -1}, 0.01 ng g{sup -1} and 0.06 ng g{sup -1} for Ru, Rh, Pd, Ir and Pt, respectively. LA-ICP-IDMS was applied to different geological reference materials (TDB-1, WGB-1, UMT-1, WMG-1, SARM-7) and the road dust reference material BCR-723, which are only certified for some of the PGEs. Comparisons with certified values as well as with indicative values from the literature demonstrated the validity of the LA-ICP-IDMS method. The PGE concentrations in subsamples of the road dust reference material correspond to a normal distribution, whereas the distributions in the geological reference materials TDB-1, WGB-1, UMT-1, WMG-1, and SARM-7 are more complex. For example, in the case of Ru, a logarithmic normal distribution best fits the analyzed concentrations in TDB-1 subsamples, whereas a pronounced nugget effect was found for Pt in most geological samples. (orig.)

  6. Direct determination of platinum group elements and their distributions in geological and environmental samples at the ng g(-1) level using LA-ICP-IDMS.

    Science.gov (United States)

    Boulyga, Sergei F; Heumann, Klaus G

    2005-10-01

    Laser ablation inductively coupled plasma isotope dilution mass spectrometry (LA-ICP-IDMS) was applied to the direct and simultaneous determination of the platinum group elements (PGEs) Pt, Pd, Ru, and Ir in geological and environmental samples. A special laser ablation system with high ablation rates was used, along with sector field ICP-MS. Special attention was paid to deriving the distributions of PGEs in the pulverized samples. IDMS could not be applied to the (mono-isotopic) Rh, but the similar ablation behavior of Ru and Rh allowed Rh to be simultaneously determined via relative sensitivity coefficients. The laser ablation process produces hardly any oxide ions (which usually cause interference in PGE analysis with liquid sample injection), so the ICP-MS can be run in its low mass resolution but high-sensitivity mode. The detection limits obtained for the geological samples were 0.16 ng g(-1), 0.14 ng g(-1), 0.08 ng g(-1), 0.01 ng g(-1) and 0.06 ng g(-1) for Ru, Rh, Pd, Ir and Pt, respectively. LA-ICP-IDMS was applied to different geological reference materials (TDB-1, WGB-1, UMT-1, WMG-1, SARM-7) and the road dust reference material BCR-723, which are only certified for some of the PGEs. Comparisons with certified values as well as with indicative values from the literature demonstrated the validity of the LA-ICP-IDMS method. The PGE concentrations in subsamples of the road dust reference material correspond to a normal distribution, whereas the distributions in the geological reference materials TDB-1, WGB-1, UMT-1, WMG-1, and SARM-7 are more complex. For example, in the case of Ru, a logarithmic normal distribution best fits the analyzed concentrations in TDB-1 subsamples, whereas a pronounced nugget effect was found for Pt in most geological samples.

  7. Geological Services Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Researchers use computed tomography (CT) scanners at NETL’s Geological Services Laboratory in Morgantown, WV, to peer into geologic core samples to determine how...

  8. Set-up and calibration of a method to measure {sup 10}B concentration in biological samples by neutron autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Gadan, M.A. [National Commission for Atomic Energy (CNEA), Buenos Aires (Argentina); Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Bortolussi, S., E-mail: silva.bortolussi@pv.infn.it [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute for Nuclear Physics (INFN), Section of Pavia, Pavia (Italy); Postuma, I. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Ballarini, F. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute for Nuclear Physics (INFN), Section of Pavia, Pavia (Italy); Bruschi, P. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Protti, N.; Santoro, D.; Stella, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute for Nuclear Physics (INFN), Section of Pavia, Pavia (Italy); Cansolino, L.; Clerici, A.; Ferrari, C.; Zonta, A.; Zonta, C. [Department of Experimental Surgery, University of Pavia, Pavia (Italy); Altieri, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute for Nuclear Physics (INFN), Section of Pavia, Pavia (Italy)

    2012-03-01

    A selective uptake of boron in the tumor is the base of Boron Neutron Capture Therapy, which can destroy the tumor substantially sparing the normal tissue. In order to deliver a lethal dose to the tumor, keeping the dose absorbed by normal tissues below the tolerance level, it is mandatory to know the {sup 10}B concentration present in each kind of tissue at the moment of irradiation. This work presents the calibration procedure adopted for a boron concentration measurement method based on neutron autoradiography, where biological samples are deposited on sensitive films and irradiated in the thermal column of the TRIGA reactor (University of Pavia). The latent tracks produced in the film by the charged particles coming from the neutron capture in {sup 10}B are made visible by a proper etching, allowing the measurement of the track density. A calibration procedure with standard samples provides curves of track density as a function of boron concentration, to be used in the measurement of biological samples. In this paper, the bulk etch rate parameter and the calibration curves obtained for both liquid samples and biological tissues with known boron concentration are presented. A bulk etch rate value of (1.64 {+-} 0.02) {mu}m/h and a linear dependence with etching time were found. The plots representing the track density versus the boron concentration in a range between 5 and 50 {mu}g/g (ppm) are linear, with an angular coefficient of (1.614 {+-} 0.169){center_dot}10{sup -3} tracks/({mu}m{sup 2} ppm) for liquids and (1.598 {+-} 0.097){center_dot}10{sup -2} tracks/({mu}m{sup 2} ppm) for tissues.

  9. Minimization of the blank values in the neutron activation analysis of biological samples considering the whole procedure

    International Nuclear Information System (INIS)

    Lux, F.; Bereznai, T.; Haeberlin, T.H.

    1986-01-01

    In our determination of trace element contents of animal tissue by neutron activation analysis in the course of structure-activity relationship studies on platinum containing cancer drugs and wound healing we have tried to minimize the blank values that are caused by different sources of contamination during surgery, sampling and the activation analysis procedure. The following topics have been investigated: the abrasions from scalpels made of stainless steel, titanium or quartz; the type of surgery; the homogenisation of the samples before irradiation by use of a ball milll; the surface contaminations of the quartz ampoules that pass into the digestion solution of the irradiated samples. The appropriate measures taken in order to reduce the blank values are described. The results of analyses performed under these conditions indicate the effectiveness of the given measures, especially shown by the low values obtained for the chromium contents of the analysed muscle samples. (author)

  10. A colorimetric determination of boron in biological sample for boron neutron capture therapy (BNCT)

    International Nuclear Information System (INIS)

    Camillo, M.A.P.; Tomac Junior, U.

    1990-01-01

    The boron neutron capture therapy (BNCT) has shown better prognosis in the treatment of glyemas and gluoblastomas grade III and IV than other therapies. During the treatment the levels of Na 2 10 B 12 H 11 SH must be known in several compartiments of the organism and with this purpose the method of colorimetric determination of boron using curcumine was established. This method is simple, reprodutible and adequate sensitivity for this control. (author) [pt

  11. A colorimetric determination of boron in biological sample for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Camilo, M.A.P.; Tomac Junior, U.

    1989-01-01

    The boron neutron capture therapy (BNCT) has shown better prognosis in the treatment of gliomas and glioblastomas grade III and IV than other therapies. During the treatment of levels of Na 2 10 B 12 H 11 S H must be known in several compartments of the organism and with this purpose the method of colorimetric determination of boron using curcumin was established. This method is simples, reproducible and has adequate sensitivity for this control. (author). 7 refs, 3 figs, 1 tab

  12. The determination by irradiation with a pulsed neutron generator and delayed neutron counting of the amount of fissile material present in a sample; Determination de la quantite de matiere fissile presente dans un echantillon par irradiation au moyen d'une source pulsee de neutrons et comptage des neutrons retardes

    Energy Technology Data Exchange (ETDEWEB)

    Beliard, L; Janot, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    A preliminary study was conducted to determine the amount of fissile material present in a sample. The method used consisted in irradiating the sample by means of a pulsed neutron generator and delayed neutron counting. Results show the validity of this method provided some experimental precautions are taken. Checking on the residual proportion of fissile material in leached hulls seems possible. (authors) [French] Ce rapport rend compte d'une etude preliminaire effectuee en vue de determiner la quantite de matiere fissile presente dans un echantillon. La methode utilisee consiste a irradier l'echantillon considere au moyen d'une source puisee de neutrons et a compter les neutrons retardes produits. Les resultats obtenus permettent de conclure a la validite de la methode moyennant certaines precautions. Un controle de la teneur residuelle en matiere fissile des gaines apres traitement semble possible. (auteurs)

  13. Neutron and X-ray Tomography (NeXT) system for simultaneous, dual modality tomography

    Science.gov (United States)

    LaManna, J. M.; Hussey, D. S.; Baltic, E.; Jacobson, D. L.

    2017-11-01

    Dual mode tomography using neutrons and X-rays offers the potential of improved estimation of the composition of a sample from the complementary interaction of the two probes with the sample. We have developed a simultaneous neutron and 90 keV X-ray tomography system that is well suited to the study of porous media systems such as fuel cells, concrete, unconventional reservoir geologies, limestones, and other geological media. We present the characteristic performance of both the neutron and X-ray modalities. We illustrate the use of the simultaneous acquisition through improved phase identification in a concrete core.

  14. The analysis and attribution of the time-dependent neutron background resultant from sample irradiation in a SLOWPOKE-2 reactor

    International Nuclear Information System (INIS)

    Sellers, M.T.; Corcoran, E.C.; Kelly, D.G.

    2013-01-01

    The Royal Military College of Canada (RMCC) has commissioned a Delayed Neutron Counting (DNC) system for the analysis of special nuclear materials. A significant, time-dependent neutron background with an initial maximum count rate, more than 50 times that of the time-independent background, was characterised during the validation of this system. This time-dependent background was found to be dependent on the presence of the polyethylene (PE) vials used to transport the fissile samples, yet was not an activation product of vial impurities. The magnitude of the time-dependent background was found to be irradiation site specific and independent of the mass of PE. The capability of RMCC's DNC system to analyze the neutron count rates in time intervals 235 U contamination was present on each irradiated vial. However, Inductively Coupled Plasma-Mass Spectroscopy measurements of material leached from the outer vial surfaces after their irradiations found only trace amounts of uranium, 0.118 ± 0.048 ng of 235 U derived from natural uranium. These quantities are insufficient to account for the time-independent background, and in fact could not be discriminated from the noise associated with time-independent background. It is suggested that delayed neutron emitters are deposited in the vial surface following fission recoil, leaving the main body of uranium within the irradiation site. This hypothesis is supported by the physical cleaning of the site with materials soaked in distilled water and HNO 3 , which lowered the background from a nominal 235 U mass equivalent of 120 to 50 ng per vial. (author)

  15. Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the northeastern Alaska Range, Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska

    Science.gov (United States)

    Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

    2015-01-01

    The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 670 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the northeastern Alaska Range, in the Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical

  16. Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Kougarok area, Bendeleben and Teller quadrangles, Seward Peninsula, Alaska

    Science.gov (United States)

    Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

    2015-01-01

    The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 302 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Kougarok River drainage as well as smaller adjacent drainages in the Bendeleben and Teller quadrangles, Seward Peninsula, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated

  17. Minimization of the blank values in the neutron activation analysis of biological samples considering the whole procedure

    International Nuclear Information System (INIS)

    Lux, F.; Bereznai, T.; Trebert Haeberlin, S.

    1987-01-01

    During the determination of trace element contents of animal tissue by neutron activation analysis in the course of structure-activity relationship studies on platinum containing cancer drugs and wound healing the authors tried to minimize the blank values that are caused by different sources of contamination during surgery, sampling and the activation analysis procedure. The following topics were investigated: abrasions from scalpels made of stainless steel, titanium or quartz, the type of surgery, the surface contaminations of the quartz ampoules, etc. The measures to be taken to reduce tha blank values are described. (author) 19 refs.; 4 tables

  18. Instrumental neutron activation analysis of environmental samples from a region with prevalence of population disabilities in the North Gondar, Ethiopia

    International Nuclear Information System (INIS)

    Bitewlign, T.A.; Addis Ababa University, Addis Ababa; Chaubey, A.K.; Beyene, G.A.; Melikegnaw, T.H.; Mizera, Jiri; Czech Academy of Sciences, Prague; Kamenik, Jan; Krausova, Ivana; Kucera, Jan

    2017-01-01

    Instrumental neutron activation analysis (INAA) of soil, coal, water, and crops from the village of Awdarda in the North Gondar, Ethiopia, where the residents suffer from various disabilities, was performed in an attempt to elucidate the existing health problems. More than forty elements were determined in the samples analyzed. Comparison of our results with literature values indicates highly elevated contents of terrigenous elements in Awdarda cereals, possibly due to contamination by excavation and indoor combustion of local coal-bearing sediments. Impact is discussed of the elevated aluminium and the rare earth elements levels in crops on the health problems. (author)

  19. Taking account of sample finite dimensions in processing measurements of double differential cross sections of slow neutron scattering

    International Nuclear Information System (INIS)

    Lisichkin, Yu.V.; Dovbenko, A.G.; Efimenko, B.A.; Novikov, A.G.; Smirenkina, L.D.; Tikhonova, S.I.

    1979-01-01

    Described is a method of taking account of finite sample dimensions in processing measurement results of double differential cross sections (DDCS) of slow neutron scattering. A necessity of corrective approach to the account taken of the effect of sample finite dimensions is shown, and, in particular, the necessity to conduct preliminary processing of DDCS, the account being taken of attenuation coefficients of single scattered neutrons (SSN) for measurements on the sample with a container, and on the container. Correction for multiple scattering (MS) calculated on the base of the dynamic model should be obtained, the account being taken of resolution effects. To minimize the effect of the dynamic model used in calculations it is preferred to make absolute measurements of DDCS and to use the subraction method. The above method was realized in the set of programs for the BESM-5 computer. The FISC program computes the coefficients of SSN attenuation and correction for MS. The DDS program serves to compute a model DDCS averaged as per the resolution function of an instrument. The SCATL program is intended to prepare initial information necessary for the FISC program, and permits to compute the scattering law for all materials. Presented are the results of using the above method while processing experimental data on measuring DDCS of water by the DIN-1M spectrometer

  20. Neutron activation analysis of sediment core samples of Lake Erhai in southern China and a Salt Lake in India

    International Nuclear Information System (INIS)

    Toyoda, Kazuhiro; Shinozuka, Yoshitsugu; Miura, Masahiro; Moriyasu, Yuki

    2005-01-01

    The purpose of this research is in the verification of the hypothesis that the long-lived nuclide ratio of Th/Sc in the deposit sample dug up in the lake with the hinterland of the granite quality is the index of a past change of precipitation and of the event such as earthquakes. As a preceding step the relation between an environmental change and a climate change was studied by the measuring result of the ratio of Th/Sc by the neutron activation analysis about the digging core sample of the Nepalese Katmandu basin (For the past 700,000 years) and the core sample (For 40,000 years and 8,000 years of the past) in Lake Biwa. (H. Katsuta)

  1. Major and minor elements analysis in soil samples by neutron activation analysis and X-ray fluorescence

    International Nuclear Information System (INIS)

    Morcelli, Claudia Petronilho Ribeiro; Ana Maria Graciano; Enzweiler, Jacinta

    2002-01-01

    In the present work, Instrumental Neutron Activation Analysis (INAA) and X-Ray Fluorescence were employed to analyze major and minor elements in soil samples collected near Bandeirantes road. Elements of environmental interest, such as Al, Sb, As, Ba, Cd, Pb, Co, Cu, Cr, Fe, Mn, Mo, Ni, Se, V and Zn, which have reference background levels, were determined. The samples were dried in an oven at 40 deg C, were sieved (<2 mm), grinded and were analyzed by INAA and FRX. The aims of this work were: to evaluate the possible variations in the concentration levels in soil due to emission of particulate from vehicles and other anthropogenic sources; to compare the results obtained by using both techniques. This preliminary study showed that the concentration levels of the elements of environmental interest agree with reference values for tropical soils in the sampling sites, except for Ba, which presented higher values. (author)

  2. Semiautomatic exchanger of samples for carry out neutron activation analysis; Intercambiador semiautomatico de muestras para realizar analisis por activacion neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar H, F.; Quintana C, G. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Torres R, C. E.; Mejia J, J. O., E-mail: fortunato.aguilar@inin.gob.mx [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, Ex-Rancho La Virgen, Metepec, Estado de Mexico (Mexico)

    2015-09-15

    In this paper the design methodology and implementation of a semiautomatic exchanger of samples for the Analysis Laboratory by Neutron Activation of the Reactor department is presented. Taking into account the antecedents, the necessities of improvement are described, as well as the equipment that previously contained the Laboratory. The project of the semiautomatic exchanger of samples was developed at Instituto Nacional de Investigaciones Nucleares, with its own technology to increase independence from commercial equipment. Each element of the semiautomatic exchanger of samples is described both in the design phase as construction. The achieved results are positive and encouraging for the fulfillment of the proposed objective that is to increase the capacity of the Laboratory. (Author)

  3. Determination of arsenic, selenium and antimony by neutron activation analysis. Application to hair samples

    International Nuclear Information System (INIS)

    Das, H.A.; Hoede, D.; Nieuwendijk, B.J.T.; Sloot, H.A. van der; Teunissen, G.J.A.; Woittiez, J.R.W.

    1983-04-01

    A fast rabbit system for instrumental activation analysis with reactor neutrons is described. Its use in the determination of selenium in hair is discussed. A survey is given of the correction factors which are inherent to the use of short-lived radionuclides. An alternative to INAA is NAA based on the separation of arsenic, selenium and antimony by hydride evaporation and adsorption to active carbon. Data for some Standard Reference Materials are given. This work was done under research contract 2440/RI/RB with the IAEA

  4. Analysis by neutron activation in moss samples for the determination of Cr, Se, As and Hg

    International Nuclear Information System (INIS)

    Mejia C, R.; Garcia R, G.; Lopez R, C.; Avila P, P.; Longoria G, L. C.

    2012-10-01

    This research work, presents a study of environmental monitoring in the Metropolitan Area of Toluca Valley using as bio-monitors to the mosses (bryophytes) native of different sites, analyzing the concentrations of As, Cr, Hg and Se, present in its structure. The analysis technique used to identify and to quantify to these elements was the Analysis by Neutron Activation, a nuclear analytic technique that allowed determining the concentrations at track level for its great versatility. Likewise the morphological study of the bryophyte Leskea angustata is presented by scanning electron microscopy. (Author)

  5. Neutron activation analysis in Romania

    International Nuclear Information System (INIS)

    Apostolescu, St.

    1985-01-01

    The following basic nuclear facilities are used for neutron activation analysis: a 2000 KW VVR-S Nuclear Reactor, a U-200 Cyclotron, a 30 MeV Betatron, several 14 MeV neutron generators and a king size High Voltage tandem Van de'Graaff accelerator. The main domains of application of the thermal neutron activation analysis are: geology and mining, processing of materials, environment and biology, achaeology. Epithermal neutron activation analysis has been used for determination of uranium and thorium in ores with high Th/U ratios or high rare earth contents. One low energy accelerator, used as 14.1 Mev neutron source, is provided with special equipmen for oxigen and low mass elements determination. An useful alternating way to support fast neutron activation analysis is an accurate theoretical description of the fast neutron induced reactions based on the statistical model (Hauser-Feubach STAPRE code) and the preequilibrium decay geometry dependent model. A gravitational sample changer has been installed at the end of a beam line of the Cyclotron, which enables to perform charged particles activation analysis for protein determination in grains

  6. A new method for the homogeneous precipitative separation of trace level lanthanides as oxalates: application to different types of geological samples

    International Nuclear Information System (INIS)

    Premadas, A.; Cyriac, Bincy; Kesavan, V.S.

    2013-01-01

    Oxalate precipitation of lanthanides in acidic medium is a widely used selective group separation method at percentage to trace level in different types of geological samples. Most of the procedures are based on the heterogeneous oxalate precipitation of lanthanides using calcium as carrier. In the heterogeneous precipitation, the co-precipitated impurities from the matrix elements are more, besides if the pH at the time of precipitation is not monitored carefully there is a chance of losing some of the lanthanides. In this report, we present a new homogeneous oxalate precipitation of trace level lanthanides from different types of geological samples using calcium as carrier. In the present method pH is getting adjusted (pH ∼1) on its own, after the hydrolysis of urea added to the sample solution. This acidic pH is essential for the complete precipitation of the lanthanides. Therefore, no critical parameter adjustment for the precipitation is involved in the proposed method. The oxalate precipitate obtained was in crystalline nature which facilitates the fast settlement, easy filtration; besides the co-precipitated matrix elements are very less as compared to normal heterogeneous oxalate precipitation of lanthanides. Another advantage is more quantity of the sample can be taken for the separation of lanthanides which is a limitation for other separation methods reported. Accuracy of the method was checked by analyzing nine international reference materials comprising different types of geological samples obtained from Canadian Certified Reference Project Materials such as syenite samples SY-2, SY-3 and SY-4; gabro sample MRG-1; soil samples SO-1 and SO-2; iron formation sample FeR-2; lake sediments LKSD-2 and LKSD-4. The values of the lanthanides obtained for these reference materials are comparable with recommended values, indicating that the method is accurate. The reproducibility is characterized by a relative standard deviation (RSD) of 1 to 6% (n=4). (author)

  7. Use of higher order signal moments and high speed digital sampling technique for neutron flux measurements

    Science.gov (United States)

    Baers, L. B.; Gutierrez, T. Rivero; Mendoza, R. A. Carrillo; Santana, G. Jimenez

    1993-08-01

    The second (conventional variance or Campbell signal), the third, and the modified fourth order central signal moments associated with the amplified and filtered currents from two electrodes of an ex-core neutron sensitive fission detector were measured versus the reactor power of the 1-MW TRIGA reactor in Mexico City. Two channels of a high-speed (400-MHz) multiplexing data sampler and an analog-to-digital converter with 12-b resolution and 1-Mword buffer memory were used. The data were further retrieved into a PC, and estimates for autocorrelation and cross-correlation moments up to the fifth order, coherence, skewness, excess, etc., quantities were calculated offline. Five-mode operation of the detector was achieved, including conventional counting rates and currents in agreement with theory and the authors' previous results with analog techniques. The signals are proportional to the neutron flux and reactor power in some flux ranges. The suppression of background noise is improved and the lower limit of the measurement range is extended as the order of moment is increased, in agreement with theory.

  8. Applied research and development of neutron activation analysis - The study on human health and environment by neutron activation analysis of biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Seung Yeon; Yoo, Jong Ik; Lee, Jae Kwang; Lee, Sung Jun; Lee, Sang Sun; Jeon, Ki Hong; Na, Kyung Won; Kang, Sang Hun [Yonsei University, Seoul (Korea)

    2000-04-01

    With the development of the precise quantitative analytical method for the analysis of trace elements in the various biological samples such as hair and food, evaluation in view of health and environment to the trace elements in various sources which can be introduced inside human body was done. The trace elemental distribution in Korean total diet and representative food stuff was identified first. With the project the elemental distributions in supplemental healthy food and Korean and Chinese origin oriental medicine were identified. The amount of trace elements ingested with the hair analysis of oriental medicine takers were also estimated. The amounts of trace elements inhaled with the analysis of foundry air, blood and hair of foundry workers were also estimated. The basic estimation method in view of health and environment with the neutron activation analysis of biological samples such as foods and hair was established with the result. Nationwide usage system of the NAA facility in Hanaro in many different and important areas of biological area can be initiated with the results. The output of the project can support public heath, environment, and medical research area. The results can be applied for the process of micronutrients enhanced health food production and for the health safety and health status enhancement with the additional necessary data expansion and the development of various evaluation technique. 19 refs., 7 figs., 23 tabs. (Author)

  9. Determination of essential elements in dietetic sample by neutron activation analysis; Determinacao de elementos essenciais em alimentos dieteticos pela tecnica de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Siquelli, Murilo V.; Maihara, Vera A. Maihara [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Lab. de Analise por Ativacao Neutronica]. E-mail: murilo_siquelli@hotmail.com; vmaihara@ipen.br

    2005-07-01

    In the last years there has been an increase of the dietetic product consumption by people who suffer from diabetes, heart disease and by people concerned about having a healthy life as well. Despite the increase of dietetic product presents in the diet of the Brazilian population, the use of these products is still controversial. The analysis of the nutritional composition of these products is becoming important because a great number of people is changing their traditional food by dietetic products. In the literature, there is no information about the inorganic composition, mainly related to the essential elements, in the dietetic products: diet and light . In this study are presented preliminary results of the concentrations of Br, Ca, Cr, Fe, Na and Zn determined by Instrumental Neutron Activation Analysis in aspartame, saccharin and cyclamate sodium , and stevia based sweetener samples. Gelatin samples, diet and light, were also analyzed. Methodology validation was done analyzing NIST reference materials Tea Leaves (INCT-TL-1) and Mixed Polish Herbs (INCT-MPH-2). (author)

  10. University of TX Bureau of Economic Geology's Core Research Centers: The Time is Right for Registering Physical Samples and Assigning IGSN's - Workflows, Stumbling Blocks, and Successes.

    Science.gov (United States)

    Averett, A.; DeJarnett, B. B.

    2016-12-01

    The University Of Texas Bureau Of Economic Geology (BEG) serves as the geological survey for Texas and operates three geological sample repositories that house well over 2 million boxes of geological samples (cores and cuttings) and an abundant amount of geoscience data (geophysical logs, thin sections, geochemical analyses, etc.). Material is accessible and searchable online, and it is publically available to the geological community for research and education. Patrons access information about our collection by using our online core and log database (SQL format). BEG is currently undertaking a large project to: 1) improve the internal accuracy of metadata associated with the collection; 2) enhance the capabilities of the database for both BEG curators and researchers as well as our external patrons; and 3) ensure easy and efficient navigation for patrons through our online portal. As BEG undertakes this project, BEG is in the early stages of planning to export the metadata for its collection into SESAR (System for Earth Sample Registration) and have IGSN's (International GeoSample Numbers) assigned to its samples. Education regarding the value of IGSN's and an external registry (SESAR) has been crucial to receiving management support for the project because the concept and potential benefits of registering samples in a registry outside of the institution were not well-known prior to this project. Potential benefits such as increases in discoverability, repository recognition in publications, and interoperability were presented. The project was well-received by management, and BEG fully supports the effort to register our physical samples with SESAR. Since BEG is only in the initial phase of this project, any stumbling blocks, workflow issues, successes/failures, etc. can only be predicted at this point, but by mid-December, BEG expects to have several concrete issues to present in the session. Currently, our most pressing issue involves establishing the most

  11. Development of sample assay system equipped with 3He Alternative Neutron Detectors (ASAS). (2) Results of ASAS measurement test

    International Nuclear Information System (INIS)

    Tanigawa, Masafumi; Mukai, Yasunobu; Kurita, Tsutomu; Makino, Risa; Nakamura, Hironobu; Tobita, Hiroshi; Ohzu, Akira; Kureta, Masatoshi; Seya, Michio

    2015-01-01

    Against the background of the serious shortage of 3 He gas, design and development of a new detector equipped ZnS/ 10 B 2 O 3 ceramic scintillation neutron detectors in JAEA, with the support of the government (the Ministry of Education, Culture, Sports, Science and Technology). The design of the alternative 3 He detector is referred from INVS (INVentory Sample assay system (HLNCC (High Level Neutron Coincidence Counter) type)) which is being used for the verification of MOX powder etc. and is named it as ASAS (Alternative Sample Assay System). In order to prove the Pu quantitative performance as an alternative technology, several measurement tests and comparison test with INVS were conducted using ASAS. In these tests, evaluation of fundamental performance (counting efficiency and die-away time) and uncertainty evaluations were implemented. As a result, although fundamental performance of ASAS was not achieved to the one of INVS, we could confirm that ASAS has almost the same Pu quantitative performance including measurement uncertainty as that of INVS. (author)

  12. Validation and uncertainty estimation of fast neutron activation analysis method for Cu, Fe, Al, Si elements in sediment samples

    International Nuclear Information System (INIS)

    Sunardi; Samin Prihatin

    2010-01-01

    Validation and uncertainty estimation of Fast Neutron Activation Analysis (FNAA) method for Cu, Fe, Al, Si elements in sediment samples has been conduced. The aim of the research is to confirm whether FNAA method is still matches to ISO/lEC 17025-2005 standard. The research covered the verification, performance, validation of FNM and uncertainty estimation. Standard of SRM 8704 and sediments were weighted for certain weight and irradiated with 14 MeV fast neutron and then counted using gamma spectrometry. The result of validation method for Cu, Fe, Al, Si element showed that the accuracy were in the range of 95.89-98.68 %, while the precision were in the range 1.13-2.29 %. The result of uncertainty estimation for Cu, Fe, Al, and Si were 2.67, 1.46, 1.71 and 1.20 % respectively. From this data, it can be concluded that the FNM method is still reliable and valid for element contents analysis in samples, because the accuracy is up to 95 % and the precision is under 5 %, while the uncertainty are relatively small and suitable for the range 95 % level of confidence where the uncertainty maximum is 5 %. (author)

  13. Iron Quadrangle, Brazil. Elemental concentration determined by k0-instrumental neutron activation analysis. Part 1. Soil samples

    International Nuclear Information System (INIS)

    Menezes, M.A.B.C.; Palmieri, H.E.L.; Leonel, L.V.; Nalini, H.A.Jr.; Jacimovic, R.

    2006-01-01

    The Iron Quadrangle, Minas Gerais, Brazil, is rich in mineral occurrences and is considered one of the richest mineral-bearing regions in the world. Most investigations in this region have dealt with the determination of arsenic and mercury but so far few studies have been carried out aiming at determining other important elements. Having in mind the potential risk caused by mineral activities, this study was developed in order to assess the potential influence of the soil on foodstuffs. The soil samples were collected from three sites inside and outside the Iron Quadrangle. The samples were analyzed at the Laboratory for Neutron Activation Analysis, CDTN/CNEN by the k 0 -instrumental neutron activation analysis. This paper reports the elemental concentration determined in soil and emphasises the elements cited in the Brazilian environmental legislation for soil. This work also confirms the high elemental concentration of several minerals, however, it is difficult to distinguish the contamination from anthropogenic activities from the natural occurrence. (author)

  14. Description of the U.S. Geological Survey's water-quality sampling and water-level monitoring program at the Hallam Nuclear Facility, August through September 1997

    International Nuclear Information System (INIS)

    1997-01-01

    A water-quality and water-level program between the US Department of Energy (USDOE) and the US Geological Survey (USGS) was re-established in August 1997 to (1) collect one set of water-quality samples from 17 of the 19 USDOE monitor wells, and (2) make five water-level measurements during a 2-month period from the 19 USDOE monitor wells at the Hallam Nuclear Facility, Hallam, Nebraska. Data from these wells are presented

  15. A comparative study of 232Th and 238U activity estimation in soil samples by gamma spectrometry and neutron activation analysis technique

    International Nuclear Information System (INIS)

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

    2012-01-01

    Neutron activation analysis (NAA) is a well-established analytical technique. It has many advantages as compared to the other commonly used techniques. NAA can be performed in a variety of ways depending on the element, its activity level in the sample, interference from the sample matrix and other elements, etc. This technique is used to get high analytical sensitivity and low detection limits (ppm to ppb). The high sensitivity is due to the irradiation at high neutron flux available from the research reactors and the activity measurement is done using high resolution HPGe detectors. In this paper, the activity estimation of soil samples using neutron activation and direct gamma spectrometry methods are compared. Even though the weights of samples considered and samples preparation methods are different for these two methods, the estimated activity values are comparable. (author)

  16. Comparison of partial least squares and lasso regression techniques as applied to laser-induced breakdown spectroscopy of geological samples

    International Nuclear Information System (INIS)

    Dyar, M.D.; Carmosino, M.L.; Breves, E.A.; Ozanne, M.V.; Clegg, S.M.; Wiens, R.C.

    2012-01-01

    A remote laser-induced breakdown spectrometer (LIBS) designed to simulate the ChemCam instrument on the Mars Science Laboratory Rover Curiosity was used to probe 100 geologic samples at a 9-m standoff distance. ChemCam consists of an integrated remote LIBS instrument that will probe samples up to 7 m from the mast of the rover and a remote micro-imager (RMI) that will record context images. The elemental compositions of 100 igneous and highly-metamorphosed rocks are determined with LIBS using three variations of multivariate analysis, with a goal of improving the analytical accuracy. Two forms of partial least squares (PLS) regression are employed with finely-tuned parameters: PLS-1 regresses a single response variable (elemental concentration) against the observation variables (spectra, or intensity at each of 6144 spectrometer channels), while PLS-2 simultaneously regresses multiple response variables (concentrations of the ten major elements in rocks) against the observation predictor variables, taking advantage of natural correlations between elements. Those results are contrasted with those from the multivariate regression technique of the least absolute shrinkage and selection operator (lasso), which is a penalized shrunken regression method that selects the specific channels for each element that explain the most variance in the concentration of that element. To make this comparison, we use results of cross-validation and of held-out testing, and employ unscaled and uncentered spectral intensity data because all of the input variables are already in the same units. Results demonstrate that the lasso, PLS-1, and PLS-2 all yield comparable results in terms of accuracy for this dataset. However, the interpretability of these methods differs greatly in terms of fundamental understanding of LIBS emissions. PLS techniques generate principal components, linear combinations of intensities at any number of spectrometer channels, which explain as much variance in the

  17. Comparison of partial least squares and lasso regression techniques as applied to laser-induced breakdown spectroscopy of geological samples

    Energy Technology Data Exchange (ETDEWEB)

    Dyar, M.D., E-mail: mdyar@mtholyoke.edu [Dept. of Astronomy, Mount Holyoke College, 50 College St., South Hadley, MA 01075 (United States); Carmosino, M.L.; Breves, E.A.; Ozanne, M.V. [Dept. of Astronomy, Mount Holyoke College, 50 College St., South Hadley, MA 01075 (United States); Clegg, S.M.; Wiens, R.C. [Los Alamos National Laboratory, P.O. Box 1663, MS J565, Los Alamos, NM 87545 (United States)

    2012-04-15

    A remote laser-induced breakdown spectrometer (LIBS) designed to simulate the ChemCam instrument on the Mars Science Laboratory Rover Curiosity was used to probe 100 geologic samples at a 9-m standoff distance. ChemCam consists of an integrated remote LIBS instrument that will probe samples up to 7 m from the mast of the rover and a remote micro-imager (RMI) that will record context images. The elemental compositions of 100 igneous and highly-metamorphosed rocks are determined with LIBS using three variations of multivariate analysis, with a goal of improving the analytical accuracy. Two forms of partial least squares (PLS) regression are employed with finely-tuned parameters: PLS-1 regresses a single response variable (elemental concentration) against the observation variables (spectra, or intensity at each of 6144 spectrometer channels), while PLS-2 simultaneously regresses multiple response variables (concentrations of the ten major elements in rocks) against the observation predictor variables, taking advantage of natural correlations between elements. Those results are contrasted with those from the multivariate regression technique of the least absolute shrinkage and selection operator (lasso), which is a penalized shrunken regression method that selects the specific channels for each element that explain the most variance in the concentration of that element. To make this comparison, we use results of cross-validation and of held-out testing, and employ unscaled and uncentered spectral intensity data because all of the input variables are already in the same units. Results demonstrate that the lasso, PLS-1, and PLS-2 all yield comparable results in terms of accuracy for this dataset. However, the interpretability of these methods differs greatly in terms of fundamental understanding of LIBS emissions. PLS techniques generate principal components, linear combinations of intensities at any number of spectrometer channels, which explain as much variance in the

  18. Rapid radiochemical separation of short-lived radionuclides in neutron-activated samples

    International Nuclear Information System (INIS)

    Fardy, J.

    1985-11-01

    Radiochemical separation procedures based on the removal of metal ions by columns of C 18 -bonded silica gel after selective complexation are examined and the simplicity of the method demonstrated by its application to determination of Mn, Cu and Zn in neutron-activated biological material from the following solutions (pH 0-10, sulphate concentration 0,18M and 1,44M SO 4 ): 8-hydroxyquinoline (oxine), ammonium pyrrolidinedithiocarbamate (APDC), cupferron (CUP), 1-(2-pyridylazo)-2-naphthol (PAN), 1-(2'-thiazolylazo)-2-naphthol (TAN), 4-(2-pyridylazo) resorcinol (PAR), diethylammonium diethyldithiocarbamate (DDC), potassium ethyl xanthate (PEX), acetylacetone (AcAc) or thenoyltrifluoracetone (TTA). The method is rapid and reliable and readily adaptable in all radiochemical laboratories

  19. Analysis of toxic trace elements in sea food samples by neutron activation

    International Nuclear Information System (INIS)

    Sarmani, S.; Majid, A.A.; Wood, A.K.; Hamzah, Z.

    1993-01-01

    The contents of toxic and essential trace element were analysed such as As, Hg, Se and Zn by neutron activation analysis in coastal fishes consumed by the general population of Malaysia. The mean values of the elements analysed expressed in mg/kg fresh weight ranged 1.42-5.61, 0.06-0.42, 4.2-20.6, 0.41-1.28 for As, Hg, Zn and Se, respectively. The maximum permissible limit for As in food was set at 1.0 mg/kg under the Malaysian Food Regulations. The results showed that consumption of coastal fishes is not permitted under the regulations, while the levels of Hg, Se and Zn were within the permissible limits. The daily dietary intake of As and Hg at 400 μg and 30 μg respectively are still within the tolerance levels. (author) 9 refs.; 2 tabs

  20. Simultaneous multi-element determination in different seed samples of Dodonaea viscosa hopseed using instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    El-Sweify, Fatma H.; El-Amir, Mahmoud A.; Mostafa, Mohamed; Ramadan, Hala E.; Rashad, Ghada M.

    2016-01-01

    Instrumental neutron activation analysis technique (INAA) was applied for nondestructive multi-element analysis of seed samples of the plant Dodonaea viscosa hopseed. This plant is distributed all over Egypt, because of its suitable properties. The samples were collected from some bushes grown at different sites in some governorates, in July of each year during the period from 2004 to 2011. The determined elements are: Co, Cs, Eu, Fe, Hg, Ni, Rb, Sc, Se, Sr and Zn, under the chosen irradiation and cooling times. The content of some elements has been compared with data obtained from previous work on analysis of various kinds of seeds. The influence of some parameters on the determined elemental content is discussed. Standard reference materials IAEA-155 and IAEA-V-10 were used to assure quality control, accuracy and precision of the technique.

  1. Elemental analysis of soil and plant samples at El-Manzala lake neutron activation analysis technique. Vol. 4

    Energy Technology Data Exchange (ETDEWEB)

    Eissa, E A; Rofail, N B; Hassan, A M [Reactor and Neutron Physics Department, Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt); Abd El-Haleem, A S [Radiactive Environment Pollution Department, Hot Laboratories Center, Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt); El-Abbady, W H [Phsics Department, Faculty of Science , Al-Azhar University, (Egypt)

    1996-03-01

    Soil and plant samples were collected from from two locations, Bahr El-Baker, and Bahr kados at the manzala lake, where, where high pollution is expected. The samples were especially treated and prepared for investigation by thermal neutron activation analysis (NAA). The irradiation facilities of the first egyptian research reactor (ET-R R-1), and the hyper pure germanium (HPGe) detection system were used for analysis. Among the 34 identified Fe, Co, As, Cd, Te, La, Sm, Rb, Hg, Th, and U are of a special significance because of the their toxic deleterious impact on living organisms. This work is part of a research project concerning pollution studies on the river Nile and some lakes of egypt. The data obtained in the present work stands as a reference basic record for any future follow up of contamination level. 1 tab.

  2. Elemental analysis of soil and plant samples at El-Manzala lake neutron activation analysis technique. Vol. 4

    International Nuclear Information System (INIS)

    Eissa, E.A.; Rofail, N.B.; Hassan, A.M.; Abd El-Haleem, A.S.; El-Abbady, W.H.

    1996-01-01

    Soil and plant samples were collected from from two locations, Bahr El-Baker, and Bahr kados at the manzala lake, where, where high pollution is expected. The samples were especially treated and prepared for investigation by thermal neutron activation analysis (NAA). The irradiation facilities of the first egyptian research reactor (ET-R R-1), and the hyper pure germanium (HPGe) detection system were used for analysis. Among the 34 identified Fe, Co, As, Cd, Te, La, Sm, Rb, Hg, Th, and U are of a special significance because of the their toxic deleterious impact on living organisms. This work is part of a research project concerning pollution studies on the river Nile and some lakes of egypt. The data obtained in the present work stands as a reference basic record for any future follow up of contamination level. 1 tab

  3. Simultaneous multi-element determination in different seed samples of Dodonaea viscosa hopseed using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    El-Sweify, Fatma H.; El-Amir, Mahmoud A.; Mostafa, Mohamed; Ramadan, Hala E.; Rashad, Ghada M. [Atomic Energy Authority, Cairo (Egypt). Hot Lab. Center

    2016-07-01

    Instrumental neutron activation analysis technique (INAA) was applied for nondestructive multi-element analysis of seed samples of the plant Dodonaea viscosa hopseed. This plant is distributed all over Egypt, because of its suitable properties. The samples were collected from some bushes grown at different sites in some governorates, in July of each year during the period from 2004 to 2011. The determined elements are: Co, Cs, Eu, Fe, Hg, Ni, Rb, Sc, Se, Sr and Zn, under the chosen irradiation and cooling times. The content of some elements has been compared with data obtained from previous work on analysis of various kinds of seeds. The influence of some parameters on the determined elemental content is discussed. Standard reference materials IAEA-155 and IAEA-V-10 were used to assure quality control, accuracy and precision of the technique.

  4. Determination of the total amount of organically bound chlorine, bromine and iodine in environmental samples by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gether, J; Lunde, G [Central Institute for Industrial Research, Oslo (Norway); Steinnes, E [Institutt for Atomenergi, Kjeller (Norway)

    1979-07-01

    The determination of chlorine, bromine and iodine present as non-polar, hydrophobic hydrocarbons in environmental samples is reported. The organohalogen compounds are seprated from water into an organic phase by on-site liquid-liquid extraction, and form biological material by procedures based on lipid phase extraction and codistillation. After removal of inorganic halides by washing with water and concentration of the sample by evaporation of the solvent, the resulting extracts are analyzed for their chlorine, bromine and iodine contents by instrumental neutron activation analysus. Strict attention is paid to the possibility of contamination in every step of the procedure. Background values in routine analysis are approximately 100-200 ng of chlorine, <5 ng of bromine and <3 ng of iodine.

  5. Neutron activation analysis in minerals prospecting

    International Nuclear Information System (INIS)

    Gomez, H.; Duque O, J.

    1988-01-01

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

  6. Residual neutron-induced radionuclides in a soil sample collected in the vicinity of the criticality accident site in Tokai-mura, Japan: A Progress Report

    International Nuclear Information System (INIS)

    Nakanishi, Takashi; Hosotani, Risa; Komura, Kazuhisa; Muroyama, Toshiharu; Kofuji, Hisaki; Murata, Yoshimasa; Kimura, Shinzo; Kumar Sahoo, Sarata; Yonehara, Hidenori; Watanabe, Yoshito; Ban-nai, Tada-aki

    2000-01-01

    Residual neutron-induced radionuclides were measured in a soil sample collected in the vicinity of the location where a criticality accident occurred (in Tokai-mura, from 30 September to 1 October, 1999). Concentrations of 24 Na, 140 La, 122 Sb, 59 Fe, 124 Sb, 46 Sc, 65 Zn, 134 Cs and 60 Co in the soil sample were determined by γ-ray spectrometry, and neutron activation analysis was carried out for selected target elements in the sample. Tentative estimates of the apparent thermal and epithermal neutron fluences which reached the sample were obtained through combined analyses of 59 Fe/ 58 Fe, 124 Sb/ 123 Sb, 46 Sc/ 45 Sc, 65 Zn/ 64 Zn, 134 Cs/ 133 Cs and 60 Co/ 59 Co

  7. Application of specific extraction chromatographic methods to the Rb-Sr, Sm-Nd isotope study of geological samples: The Hombreiro-Santa Eulalia Granite (Lugo, NW Spain)

    OpenAIRE

    Santos Zalduegui, J. F.; Pin, C.; Aranguren, A.; Gil Ibarguchi, José Ignacio

    1996-01-01

    The analytical application to geological samples of three new chromatographic resins, TRU-Spec ®, Sr-Spec ® and LN-Spec ®) has been investigated. Seven samples of the Hombreiro massif (Lugo, NW Spain) have been studied, that yield a Rb-Sr age of 298 ±5 Ma (SrQ = 0.7086, MSWD = 7.64) for the magma crystallization. Sm-Nd data results for the same massif give eNd values dose to -2 at 300 Ma. This suggests that the origin of the magma might be related to the partial melting of immature sediments,...

  8. Determination of selenium in roasted beans coffee samples consumed in Algeria by radiochemical neutron activation analysis method

    International Nuclear Information System (INIS)

    Messaoudi, Mohammed; Begaa, Samir; Hamidatou, Lylia; Salhi, M'hamed

    2018-01-01

    The essential trace element selenium is a focus of attention due to its effects on human health, there being consequences of both its deficiency and excess. Due to the ultra-trace content of selenium, the neutron activation analysis method (NAA) is difficult to apply. We therefore made use of the radiochemical neutron activation analysis (RNAA) to determine Se at low level concentrations in several consumed food items in Algeria. A radiochemical procedure based on liquid-liquid separation was established in our laboratory. In this research we focused on the determination of selenium in two species of coffee: Arabica and Robusta. The accuracy of the method was assessed by analyzing the certified reference material NIST-SRM 1573a (tomato leaves). The results obtained show a selenium variation from 0.025 to 0.052 μg/g in coffee beans and an average yield of the separation of about 85%. The results of this study were compared with those obtained with samples from Brazilian, Caribbean, Indian and Kenyan coffee beans.

  9. Neutron Activation Analysis of Archaeological Pottery Samples of Large Size, Including Pieces of Low Symmetry Shape: How to Get Accurate Analytical Results in a Practical Way

    International Nuclear Information System (INIS)

    Bedregal, P.S.; Montoya, E.H.; Mendoza, P.; Ubillús, M.; Baltuano, O.; Hernández, Y.; Gago, J.; Cohen, I.M.

    2018-01-01

    The feasibility of the instrumental neutron activation analysis of entire pieces of archaeological pottery, using low thermal neutron fluxes, is examined and a new approach for the non-destructive analysis of entire pottery objects by INAA, using the conventional relative method, is described. The proposed method relies in the preparation of a comparison standard, which is a nominally identical replicate of the original object to be studied. INAA of small samples taken from that replicate allows determining its composition for the elements to be analyzed. Then the intact sample and intact standard are irradiated together with the neutrons from a nuclear reactor neutron beam, using a suitable turntable facility and monitored by neutron flux monitors. Finally, after proper decay times, the induced activities in sample, standard and flux monitors, are successively measured, by high-resolution gamma spectroscopy, using a high-efficiency germanium detector. In this way, several complicating effects such geometrical efficiency, neutron self-shielding and gamma ray attenuation are avoided and the need of complicated mathematical corrections is not needed. A potential advantage of the method is that it can be fully validated. Quantitative experiments using 7 - 13 hours of irradiation of pairs of 750 grams replicates, at low neutron fluxes of 3.9 x10 6 n cm -2 s -1 , followed by 100000 to 200000 seconds of counting in front of a 70% relative efficiency HPGe detector, led to recoveries between 90% and 110% for Sc and La. Another experiment, using pairs of replicates of small solid mud anthropomorphic objects, (weighing about 100 grams each), irradiated by 8 hours at a neutron flux of 10 9 n cm -2 s -1 , led to recoveries better than 90% and 110% for As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Lu, Rb, Sb, Sc, Sm, Ta, Tb, Th, Yb and U, showing that the proposed method is suitable for LSNAA of entire pottery or mud archaeological objects. (author)

  10. Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Haines area, Juneau and Skagway quadrangles, southeast Alaska

    Science.gov (United States)

    Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

    2015-01-01

    The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 212 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Chilkat, Klehini, Tsirku, and Takhin river drainages, as well as smaller drainages flowing into Chilkat and Chilkoot Inlets near Haines, Skagway Quadrangle, Southeast Alaska. Additionally some samples were also chosen from the Juneau gold belt, Juneau Quadrangle, Southeast Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical

  11. Application of Conventional and K0-Based Internal Monostandard NAA Using Reactor Neutrons for Compositional Analysis of Large Samples

    International Nuclear Information System (INIS)

    Reddy, A.V.R.; Acharya, R.; Swain, K. K.; Pujari, P.K.

    2018-01-01

    Large sample neutron activation analysis (LSNAA) work was carried out for samples of coal, uranium ore, stainless steel, ancient and new clay potteries, dross and clay pottery replica from Peru using low flux high thermalized irradiation sites. Large as well as non-standard geometry samples (1 g - 0.5 kg) were irradiated using thermal column (TC) facility of Apsara reactor as well as graphite reflector position of critical facility (CF) at Bhabha Atomic Research Centre, Mumbai. Small size (10 - 500 mg) samples were also irradiated at core position of Apsara reactor, pneumatic carrier facility (PCF) of Dhruva reactor and pneumatic fast transfer facility (PFTS) of KAMINI reactor. Irradiation positions were characterized using indium flux monitor for TC and CF whereas multi monitors were used at other positions. Radioactive assay was carried out using high resolution gamma ray spectrometry. The k0-based internal monostandard NAA (IM-NAA) method was used to determine elemental concentration ratios with respect to Na in coal and uranium ore samples, Sc in pottery samples and Fe in stainless steel. Insitu relative detection efficiency for each irradiated sample was obtained using γ rays of activation products in the required energy range. Representative sample sizes were arrived at for coal and uranium ore from the plots of La/Na ratios as a function of the mass of the sample. For stainless steel sample of SS 304L, the absolute concentrations were calculated from concentration ratios by mass balance approach since all the major elements (Fe, Cr, Ni and Mn) were amenable to NAA. Concentration ratios obtained by IM-NAA were used for provenance study of 30 clay potteries, obtained from excavated Buddhist sites of AP, India. The La to Ce concentration ratios were used for preliminary grouping and concentration ratios of 15 elements with respect to Sc were used by statistical cluster analysis for confirmation of grouping. Concentrations of Au and Ag were determined in not so

  12. Design and building of a homemade sample changer for automation of the irradiation in neutron activation analysis technique

    International Nuclear Information System (INIS)

    Gago, Javier; Hernandez, Yuri; Baltuano, Oscar; Bedregal, Patricia; Lopez, Yon; Urquizo, Rafael

    2014-01-01

    Because the RP-10 research reactor operates during weekends, it was necessary to design and build a sample changer for irradiation as part of the automation process of neutron activation analysis technique. The device is formed by an aluminum turntable disk which can accommodate 19 polyethylene capsules, containing samples to be sent using the pneumatic transfer system from the laboratory to the irradiation position. The system is operate by a control switchboard to send and return capsules in a variable preset time and by two different ways, allowing the determination of short, medium and long lived radionuclides. Also another mechanism is designed called 'exchange valve' for changing travel paths (pipelines) allowing the irradiated samples to be stored for a longer time in the reactor hall. The system design has allowed complete automation of this technique, enabling the irradiation of samples without the presence of an analyst. The design, construction and operation of the device is described and presented in this article. (authors).

  13. A Monte Carlo Library Least Square approach in the Neutron Inelastic-scattering and Thermal-capture Analysis (NISTA) process in bulk coal samples

    Science.gov (United States)

    Reyhancan, Iskender Atilla; Ebrahimi, Alborz; Çolak, Üner; Erduran, M. Nizamettin; Angin, Nergis

    2017-01-01

    A new Monte-Carlo Library Least Square (MCLLS) approach for treating non-linear radiation analysis problem in Neutron Inelastic-scattering and Thermal-capture Analysis (NISTA) was developed. 14 MeV neutrons were produced by a neutron generator via the 3H (2H , n) 4He reaction. The prompt gamma ray spectra from bulk samples of seven different materials were measured by a Bismuth Germanate (BGO) gamma detection system. Polyethylene was used as neutron moderator along with iron and lead as neutron and gamma ray shielding, respectively. The gamma detection system was equipped with a list mode data acquisition system which streams spectroscopy data directly to the computer, event-by-event. A GEANT4 simulation toolkit was used for generating the single-element libraries of all the elements of interest. These libraries were then used in a Linear Library Least Square (LLLS) approach with an unknown experimental sample spectrum to fit it with the calculated elemental libraries. GEANT4 simulation results were also used for the selection of the neutron shielding material.

  14. Design of a thermal neutron field by 252Cf source for measurement of 10B concentrations in the blood samples for BNCT

    International Nuclear Information System (INIS)

    Naito, H.; Sakurai, Y.; Maruhashi, A.

    2006-01-01

    10 B concentrations in the blood samples for BNCT has been estimated due to amounts of prompt gamma rays from 10 B in the fields of thermal neutrons from a special guide tube attached to research reactor. A system using radioisotopes as the source of thermal neutron fields has advantages that are convenient and low cost because it doesn't need running of a reactor or an accelerator. The validity of 252 Cf as a neutron source for 10 B concentrations detection system was investigated. This system is composed of D 2 O moderator, Pb reflector/filter, C reflector, and LiF filter. A thermal neutron field with low background gamma-rays is obtained. A large source of 252 Cf is required to obtain a sufficient flux. (author)

  15. Development of a radiochemical neutron activation analysis procedure for determination of rhenium in biological and environmental samples at ultratrace level

    International Nuclear Information System (INIS)

    Kucera, J.; Lucanikova, M.; Czech Technical Univ., Prague

    2006-01-01

    Radiochemical neutron activation procedures using liquid-liquid extraction with tetraphenylarsonium chloride in chloroform from 1M HCl and solid extraction with ALIQUAT 336 incorporated in a polyacrylonitrile binding matrix from 0.1M HCl were developed for accurate determination of rhenium in biological and environmental samples at the sub-ng x g -1 level. Concentrations of Re in the range of 0.1 to 2.4 ng x g -1 were determined in several botanical reference materials (RM), while in a RM of road dust a value of ∼ 10 ng x g -1 was found. Significantly elevated values of Re, up to 90 ng x g -1 were found in seaweed (brown algae). Results for Re in the brown algae Fucus vesiculosus in which elevated 99 Tc values had previously been determined suggested possible competition between Re and Tc in the accumulation process. (author)

  16. Neutron activation analysis of some ancient and modern Chinese Jun Porcelain samples

    International Nuclear Information System (INIS)

    Gao Zhengyao; Wang Jie; Chen Songhua; Huang Zhongxiang; Han Song; Jia Xiuqin

    1997-01-01

    Up to 43 glaze and body samples of ancient and modern Chinese Jun Porcelain and other porcelain are chosen and contents of 36 elements for each sample are determined by NAA. The NAA data are then analysed by the fuzzy cluster method. The result shows that although the ancient Jun Porcelain samples span leaped 600 years and are from different kilns and their glaze colors are utterly different, they have a long-term, stable and mainly the same supply of raw material. The relation between ancient Jun Porcelain and ancient Ru Porcelain is also preliminarily analysed. It is found that only few modern Jun Porcelain samples are similar to ancient Jun Porcelain but the majority of them are different from ancient ones

  17. Neutron beam applications - Polymer study and sample environment development for HANARO SANS instrument

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Doo [Kyunghee University, Seoul (Korea); Char, Kook Heon [Seoul National University, Seoul (Korea)

    2000-04-01

    A new SANS instrument will be installed in HANARO reactor near future and in parallel it is necessary to develop the sample environment facilities. One of the basic items is the equipment to control the sample temperature of cell block with auto-sample changer. It is required to develop a control software for this purpose. In addition, softwares of the aquisition and analysis for SANS instrument must be developed and supplied in order to function properly. PS/PI block copolymer research in NIST will provide the general understanding of SANS instrument and instrument-related valuable informations such as standard sample for SANS and know-hows of the instrument building. The following are the results of this research. a. Construction of sample cell block. b. Software to control the temperature and auto-sample changer. c. Acquisition of the SANS data analysis routine and its modification for HANARO SANS. d. PS/PI block copolymer research in NIST. e. Calibration data of NIST and HANARO SANS for comparison. 39 figs., 2 tabs. (Author)

  18. Accurate determination of trace amounts of phosphorus in geological samples by inductively coupled plasma atomic emission spectrometry with ion-exchange separation

    International Nuclear Information System (INIS)

    Asoh, Kazuya; Ebihara, Mitsuru

    2013-01-01

    Graphical abstract: -- Highlights: •We set up an effective ICP-AES procedure for determining trace P in rock samples. •Some certified values of P for reference rock samples were proved to be doubtful. •Accurate and reliable data were presented for a suite of geological reference rocks. -- Abstract: In order to determine trace amounts of phosphorus in geological and cosmochemical rock samples, simple as well as reliable analytical schemes using an ICP-AES instrument were investigated. A (conventional) ICP-AES procedure could determine phosphorus contents at the level of several 100 μg g −1 with a reasonable reproducibility ( −1 ; 1σ). An ICP-AES procedure coupled with matrix-separation using cation and anion exchange resins could lower the quantification level down to 1 μg g −1 or even lower under the present experimental conditions. The matrix-separation ICP-AES procedure developed in this study was applied to twenty-one geological reference samples issued by Geological Survey of Japan. Obtained values vary from 1250 μg g −1 for JB-3 (basalt) to 2.07 μg g −1 for JCt-1 (carbonate). Matrix-separation ICP-AES yielded reasonable reproducibility (less than 8.3%; 1σ) of three replicate analyses for all the samples analyzed. In comparison of our data with certificate values as well as literature or reported values, there appear to be an apparent (and large) discrepancy between our values and certificate/reported values regardless of phosphorus contents. Based on the reproducibility of our data and the analytical capability of the matrix-separation ICP-AES procedure developed in this study (in terms of quantification limit, recovery, selectivity of an analyte through pre-concentration process, etc.), it is concluded that certified values for several reference standard rocks should be reevaluated and revised accordingly. It may be further pointed that some phosphorus data reported in literatures should be critically evaluated when they are to be

  19. Automation of Sample Transfer and Counting on Fast Neutron ActivationSystem

    International Nuclear Information System (INIS)

    Dewita; Budi-Santoso; Darsono

    2000-01-01

    The automation of sample transfer and counting were the transfer processof the sample to the activation and counting place which have been done byswitch (manually) previously, than being developed by automaticallyprogrammed logic instructions. The development was done by constructed theelectronics hardware and software for that communication. Transfer timemeasurement is on seconds and was done automatically with an error 1.6 ms.The counting and activation time were decided by the user on seconds andminutes, the execution error on minutes was 8.2 ms. This development systemwill be possible for measuring short half live elements and cyclic activationprocesses. (author)

  20. Application of instrument neutron-activation analysis in a comparative investigation of soil samples

    Energy Technology Data Exchange (ETDEWEB)

    Dimitrov, D. (Institute po Kriminalistika i Kriminologiya, Sofia (Bulgaria))

    1983-01-01

    A quantitative measurement of the contents of 17 chemical elements in soil samples, collected using the existing network from the surface of five cultivated areas in Bulgaria has been carried out. The values obtained have been used to calculate the evaluations psub(i) of the dispersions and for the ordering of the chemical elements according to their importance in criminology. The possibility for criminological comparison of single soil samples using the contents of the five most important elements - Th, Fe, Sc, Ce and Mn has been shown.

  1. Application of instrument neutron-activation analysis in a comparative investigation of soil samples

    International Nuclear Information System (INIS)

    Dimitrov, D.

    1983-01-01

    A quantitative measurement of the contents of 17 chemical elements in soil samples, collected using the existing network from the surface of five cultivated areas in Bulgaria has been carried out. The values obtained have been used to calculate the evaluations psub(i) of the dispersions and for the ordering of the chemical elements according to their importance in criminology. The possibility for criminological comparison of single soil samples using the contents of the five most important elements - Th, Fe, Sc, Ce and Mn has been shown. (author)

  2. Application of neutron activation analysis for mercury species determination in scalp hair samples from Malaysia, Libya and Jordan

    International Nuclear Information System (INIS)

    Sarmani, S.B.; Alakili, I.

    2004-01-01

    Neutron activation analysis was used to determine the levels of total mercury and methylmercury in hair samples obtained from 400 Malaysian (Kuala Lumpur), Libyan (Benghazi) and Jordanian (Amman) donors. Results show that the level of total mercury in hair samples of the Malaysian group (3.38 mg x kg -1 ) was significantly higher than those of Libyan (0.81 mg x kg -1 ) and Jordanian groups (0.69 mg x kg -1 ). Likewise, a significant difference was found between the level of methylmercury of the Malaysian group (1.13 mg x kg -1 ) and those of the Libyan (0.04 mg x kg -1 ) and Jordanian groups (0.13 mg x kg -1 ). This difference could be attributed to the variation in life habits especially fish diet and to the local environment of each population. On the other hand, no significant differences were found between the level of total mercury and methylmercury in hair samples of the Libyan and Jordanian residents. (author)

  3. Large-sample neutron activation analysis in mass balance and nutritional studies

    NARCIS (Netherlands)

    van de Wiel, A.; Blaauw, Menno

    2018-01-01

    Low concentrations of elements in food can be measured with various techniques, mostly in small samples (mg). These techniques provide only reliable data when the element is distributed homogeneously in the material to be analysed either naturally or after a homogenisation procedure. When this is

  4. Analysis of mercury and selenium in biological samples by neutron activation analysis

    International Nuclear Information System (INIS)

    Catharino, Marilia Gabriela Miranda

    2002-01-01

    In the present work, hair samples from populations suspected of contamination by mercury, in the localities of Serra do Navio, Vila Nova and Tartarugalzinho, in the State of Amapa, were analyzed. Hair samples of children under odontopediatric treatment were also analyzed for mercury, in order to study the possibility of transfer of mercury from the dental amalgam and also to obtain data of hair mercury in a control population of children. Another step of the work was the development of a method for the determination of selenium, by using the short-lived radioisotope 77 mSe. After the certification of the method it was applied to the analysis of hair, nails and a vitamin supplement. A comparison was made with the results obtain ed by using the long-lived radioisotope of selenium, 75 Se. The results obtained for mercury in the hair samples of populations living in the State of Amapa have shown that the mercury concentrations in these populations are much higher than in the controls. As for the hair samples of children under treatment with mercury amalgam, no significant differences were found in the concentrations of mercury after the treatment. On the other hand, these data were important to obtain data for a control population of children. The results obtained by using the radioisotope 77 mSe showed that the method developed was suitable for the analyzed matrixes and the results were similar to the ones obtained by employing the usual AANI method, with the radioisotope 75 Se. (author)

  5. Recoil Reactions in Neutron-Activation Analysis. The Szilard-Chalmers Effect Applied in the Analysis of Biological Samples; II. Transfer of Activities from Container Material to Sample

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D

    1965-01-15

    The present investigation consists of two parts. The one part concerns the application of the Szilard-Chalmers effect in the separation of activities from neutron-irradiated biological material. The nuclides As-76, Au-198, Br-82, Ca-47, Cd-115, Cl-38, Co-60, Cr-51, Cs-134, Cu-64, Fe-59, Mg-27, Mo-99, Na-24, P-32, Rb-86, Se-75 and Zn-65 were extracted from either liver tissue, whole blood or muscle tissue. The extractions were made in water, 0.1 N HCl, 1 N HCl or conc. HCl respectively. The nuclides belonging to the alkali metals together with Br and Cl, were found present in the water and hydrochloric extracts to 96 per cent or more. In the conc. HCl extracts, the greater part of the nuclides were recovered to 90 per cent or more. The enrichment of the different nuclides obtained in the Szilard-Chalmers process was investigated as follows. After extraction of the nuclides from the irradiated material the solution obtained was divided into two parts, one of which was reactivated. The specific activities of the nuclides in the two solutions were then compared, thus giving the enrichment factor In one case, the residue of organic material after extraction was reactivated and the activity compared to the initial one. The effect of dilution together with the application of short irradiation periods favouring higher yield was investigated in the separation of Fe-59 from whole blood samples irradiated in frozen conditions. The other part of the investigation concerns an estimation of the amounts of the activities originating from polyethylene and quartz containers transferred to container surface due to the recoil effect in the thermal neutron-capture process, thus causing contamination of the sample. The universal range-energy relationship given by Lindhard and Scharff has been applied in these calculations. As regards containers with impurities in the ppm region, the amounts of activities transferred owing to this effect were found to be quite negligible. However, when

  6. Development of neutron science and technology

    International Nuclear Information System (INIS)

    Lee, Ki Hong; Seong, Baik Seok; Lee, Jeong Soo

    2012-04-01

    Using various neutron scattering, imaging, and activation analysis instruments and irradiation facility and capsules, the short-term industrial application and mid and long-term basic science with neutrons was carried out. In this regard, we proposed the utilization of the neutron scattering and diffraction techniques to the study of physical, mechanical material properties in industrial components. The nano magnetic thin film structure study using neutron reflectometry, spin structure and dynamics study using neutron scattering, hydrogen combination structure study using single crystal diffraction were carried out. The triple-axis spectrometer has been installed. Also, a new growth facility of single crystal has been developed to supply crystals for the neutron scattering experiment. We have contributed to the performance enhancement of hydrogen fuel cell by the development of quantitative neutron radiography technology and developed the differential phase imaging technology using silicon grating. To perform precise neutron activation analysis, a Compton suppressed gamma-ray spectroscopy system was installed. Through the analysis of actual samples as well as geological and biological reference materials, performance test was carried out. We built up analytical data base and develope integrated analytical program for INAA/PGAA. The analysis and evaluation technology of the irradiation capsule test in HANARO for the commercial and future nuclear reactor systems was improved

  7. Radiography and tomography with polarized neutrons

    International Nuclear Information System (INIS)

    Treimer, Wolfgang

    2014-01-01

    Neutron imaging became important when, besides providing impressive radiographic and tomographic images of various objects, physical, quantification of chemical, morphological or other parameters could be derived from 2D or 3D images. The spatial resolution of approximately 50 µm (and less) yields real space images of the bulk of specimens with more than some cm 3 in volume. Thus the physics or chemistry of structures in a sample can be compared with scattering functions obtained e.g. from neutron scattering. The advantages of using neutrons become more pronounced when the neutron spin comes into play. The interaction of neutrons with magnetism is unique due to their low attenuation by matter and because their spin is sensitive to magnetic fields. Magnetic fields, domains and quantum effects such as the Meissner effect and flux trapping can only be visualized and quantified in the bulk of matter by imaging with polarized neutrons. This additional experimental tool is gaining more and more importance. There is a large number of new fields that can be investigated by neutron imaging, not only in physics, but also in geology, archeology, cultural heritage, soil culture, applied material research, magnetism, etc. One of the top applications of polarized neutron imaging is the large field of superconductivity where the Meissner effect and flux pinning can be visualized and quantified. Here we will give a short summary of the results achieved by radiography and tomography with polarized neutrons. - Highlights: • Radiography and tomography with polarized neutrons yield new results concerning the suppressed Meissner effect and magnetic flux trapping. • Suppressed Meissner effect was observed in pure lead samples and niobium. • Trapped magnetic fields in cylindrical Pb samples are squeezed around the rod axis. • The shape and the amount of trapped fields could be determined and quantified

  8. Radiography and tomography with polarized neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Treimer, Wolfgang, E-mail: treimer@helmholtz-berlin.de [University of Applied Sciences, Beuth Hochschule für Technik Berlin, Department Mathematics Physics and Chemistry, Luxemburgerstr. 10, D-13353 Berlin (Germany); Helmholtz Zentrum für Materialien und Energie, Department G – GTOMO, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany)

    2014-01-15

    Neutron imaging became important when, besides providing impressive radiographic and tomographic images of various objects, physical, quantification of chemical, morphological or other parameters could be derived from 2D or 3D images. The spatial resolution of approximately 50 µm (and less) yields real space images of the bulk of specimens with more than some cm{sup 3} in volume. Thus the physics or chemistry of structures in a sample can be compared with scattering functions obtained e.g. from neutron scattering. The advantages of using neutrons become more pronounced when the neutron spin comes into play. The interaction of neutrons with magnetism is unique due to their low attenuation by matter and because their spin is sensitive to magnetic fields. Magnetic fields, domains and quantum effects such as the Meissner effect and flux trapping can only be visualized and quantified in the bulk of matter by imaging with polarized neutrons. This additional experimental tool is gaining more and more importance. There is a large number of new fields that can be investigated by neutron imaging, not only in physics, but also in geology, archeology, cultural heritage, soil culture, applied material research, magnetism, etc. One of the top applications of polarized neutron imaging is the large field of superconductivity where the Meissner effect and flux pinning can be visualized and quantified. Here we will give a short summary of the results achieved by radiography and tomography with polarized neutrons. - Highlights: • Radiography and tomography with polarized neutrons yield new results concerning the suppressed Meissner effect and magnetic flux trapping. • Suppressed Meissner effect was observed in pure lead samples and niobium. • Trapped magnetic fields in cylindrical Pb samples are squeezed around the rod axis. • The shape and the amount of trapped fields could be determined and quantified.

  9. Description of the U.S. Geological Survey's water-quality sampling and water-level monitoring program at the Hallam Nuclear Facility, June through September 1996

    International Nuclear Information System (INIS)

    1997-01-01

    A water-quality and water-level program of the US Department of Energy (USDOE) in cooperation with the US Geological Survey (USGS) was re-established in June 1996 to develop six new USDOE observation wells, collect one set of water-quality samples from 17 of the 19 USDOE observation wells, and take monthly water-level measurements for a 3-month period in all 19 USDOE observation wells at the Hallam Nuclear Facility, Hallam, Nebraska. Thirteen of the observation wells were installed by HWS Consulting Group, Inc., in June 1993 and the remaining six were installed by Applied Research Associates in August 1995

  10. Radiological and hydrochemical study of thermal and fresh groundwater samples of northern Euboea and Sperchios areas, Greece: insights into groundwater natural radioactivity and geology.

    Science.gov (United States)

    Kanellopoulos, C; Mitropoulos, P; Argyraki, A

    2018-04-04

    A radiological and hydrochemical study has been conducted on thermal and fresh groundwater samples of northern Euboea Island and eastern central Greece. Both areas are characterized by complex geology and are renowned since antiquity for their hot springs, that are exploited for therapeutic spa purposes until today. The aim of the study was to combine radiological and hydrochemical data in order to achieve a holistic water quality assessment with insights into the geology of the study areas. All samples were characterized with respect to their major and trace ion and element composition, as well as activity concentrations of 222 Rn, 226 Ra, 228 Ra, 228 Th, and 40 K. The samples demonstrated elevated natural radioactivity and U concentrations, especially in some locations of the Kamena Vourla area, reaching 179 Bq/L 222 Rn, 2.2 Bq/L 226 Ra, 2.9 Bq/L 228 Ra, and 17 μg/L U. The estimated circulation depth of thermal groundwater ranges between 250 m in central Greece and 1240 m in north Euboea study area, whereas the calculated water residence times range between 27 and 555 years. Our data suggest the possible presence of an unknown until know U-rich plutonic rock formation in Kamena Vourla area and immiscibility of the fresh and thermal groundwaters in the studied areas.

  11. A new calculation method adapted to the experimental conditions for determining samples γ-activities induced by 14 MeV neutrons

    International Nuclear Information System (INIS)

    Rzama, A.; Erramli, H.; Misdaq, M.A.

    1994-01-01

    Induced gamma-activities of different disk shaped irradiated samples and standards with 14 MeV neutrons have been determined by using a Monte Carlo calculation method adapted to the experimental conditions. The self-absorption of the multienergetic emitted gamma rays has been taken into account in the final samples activities. The influence of the different activation parameters has been studied. Na, K, Cl and P contents in biological (red beet) samples have been determined. ((orig.))

  12. Effect of interaction between irradiation-induced defects and intrinsic defects in the pinning improvement of neutron irradiated YBaCuO sample

    International Nuclear Information System (INIS)

    Topal, Ugur; Sozeri, Huseyin; Yavuz, Hasbi

    2004-01-01

    Interaction between the intrinsic (native) defects and the irradiation-induced defects created by neutron irradiation was examined for the YBCO sample. For this purpose, non-superconducting Y-211 phase was included to the Y-123 samples at different contents as a source of large pinning center. The critical current density enhancement with the irradiation for these samples were analysed and then the role of defects on pinning improvement was discussed

  13. Effect of interaction between irradiation-induced defects and intrinsic defects in the pinning improvement of neutron irradiated YBaCuO sample

    Energy Technology Data Exchange (ETDEWEB)

    Topal, Ugur; Sozeri, Huseyin; Yavuz, Hasbi

    2004-08-01

    Interaction between the intrinsic (native) defects and the irradiation-induced defects created by neutron irradiation was examined for the YBCO sample. For this purpose, non-superconducting Y-211 phase was included to the Y-123 samples at different contents as a source of large pinning center. The critical current density enhancement with the irradiation for these samples were analysed and then the role of defects on pinning improvement was discussed.

  14. Characterization of the rhyolitic rocks from the Lela ore body using neutron activation analysis

    International Nuclear Information System (INIS)

    Rodriguez, G.C.; Fortes, B.P.; Guevara, S.R.

    1998-01-01

    Instrumental neutron activation analysis (INAA) is a well-known analytical method for nondestructive, sensitive and accurate determination of elemental composition of geological samples. In the present work twenty-two elements were determined by INAA in nine rhyolitic geological samples from a wolframium ore body Lela, located in the territory of Isla de la Juventud, Cuba. The obtained results are important for the preliminary geochemical evaluation of the studied rocks. (author)

  15. Detection of 10B distributions in histological samples by NCAR using thermal and cold neutrons and photoluminiscent imaging plates. New results

    International Nuclear Information System (INIS)

    Rant, J.; Skvarc, J.; Ilic, R.; Gabel, D.; Bayon, G.; Yanagie, H.; Kobayashi, H.; Lehmann, E.; Kuehne, G.

    1999-01-01

    The Neutron Capture Autoradiography (NCAR) using various Solid State Nuclear Track Detectors (SSNTDs) is a well established and accurate method to detect and measure the distributions of 10 B in the ppm range on macroscopic and microscopic level in biological samples, such as histological sections of tumours loaded with 10 B compounds used for BNCT (e.g. 1,2). recently a new technique of NCAR using sensitive photoluminescent Imaging Plates (IP) has been proposed to detect 10 B distributions in histological sections (3), exploiting excellent detection properties of IP systems such as very high detection sensitivity and quantum detection efficiency, broad linear response and dynamic range, very small image distortion, reusability of IP and possibilities of digital autoradiography. The advantage of IP-NCAR vs. NCAR with SSNTDs should be the much lower neutron fluence (10 7 10 9 vs. 10 10 10 13 n/cm 2 with SSNTDs), no intermediate chemical treatment (track etching) and direct and fast compuitational handling and evaluation of the digitized autoradiographic image. However, the spatial resolution of the present available IP detection systems is somewhat lower (∼ 0,04 mm) than with SSNTDs (∼ 0,01 mm). Another problem with IP NCAR is rather high sensitivity of IP to all types of ionizing radiations. Therefore the background of direct and induced gamma-rays as well as of epithermal and fast neutrons has to be filtered out of thermal neutron beam to be used for IP-NCAR. To improve the signal/background ratio and to increase the detectibility of 10 B we propose to use clean cold neutron beams for the IP-NCAR of 10 B distributions in histological samples in BNCT experiments (4,5). In the present work the recent results of experiments in IP-NCAR with cold neutrons from the neutron radiographic channel of the ORPHEE reactor in Saclay and with the rather clean thermal neutron beam of the NEUTRA neutron radiography facility of the PSI (Villingen) will be presented. For the

  16. Phosphorus in biological standards and samples by thermal neutron irradiation and β-counting

    International Nuclear Information System (INIS)

    Garg, A.N.; Kumar, A.; Choudhury, R.P.

    2007-01-01

    A nondestructive NAA method based on the reaction 31 P(n,γ) 32 P (T 1/2 = 14.23 d) has been developed where the product nucleus, a pure β-emitter with end point energy 1.71 MeV is measured by using an end window G.M counter and an Al filter of 27 mg x cm -2 . 32 P was identified by measuring E β using Feather's analysis and its half-life was found to be 15.3±0.2 days in standard reference materials (SRMs) and samples. For most reference materials (RMs) from NIST (USA) and IAEA (Vienna), our values agree within ±5% of the certified values. A variety of biological samples have also been analyzed and our values are in the range; medicinal herbs (n 43), 0.29-5.23 mg/g; bhasmas (n = 19), 0.09-51.4 mg/g; vegetables (n = 8), 1.85-5.73 mg/g; lentils (n = 6), 2.1-5.5 mg/g; flours (n = 6), 1.3-3.3 mg/g; vegetarian diet (n = 5), 2.41-2.90 mg/g; fish (n = 43), 3.61-36.8 mg/g; human and animal milk (n = 6), 1.24-7.95 mg/g; commercial milk powders (n = 14), 2.76-11.9 mg/g; water from various sources (n = 14), 1-417 μg/l; human and animal blood (n = 9), 1.00-15.0 mg/g; cancerous and healthy breast tissue (n = 60), 1.00-8.63 mg/g; human hair (n = 43), 0.12-5.81 mg/g, where n is the number of samples analyzed. The method is simple, fast, and nondestructive and provides data within ±5% error limit with a detection limit of 0.1 mg/g. (author)

  17. Neutron-induced prompt gamma-ray analysis of Gulf marine environmental samples

    International Nuclear Information System (INIS)

    Yonezawa, C.; Matsue, H.; Adachi, T.; Hoshi, M.; Tachikawa, E.; Povinec, P.P.; Fowler, S.W.; Baxter, M.S.

    1999-01-01

    Multi-element composition and isotopic characteristics of the oil and contaminated materials, and measurement of historical records of marine environmental condition using annual bands in coral samples have been investigated in the program. Elemental analyses have been carried out by the PGA together with INAA and ICP-MS to obtain accurate and precise elemental characteristics of oil, marine sediment and bivalves. Fifteen elements including light elements of H, B, N, Si and Ca which cannot be determined by INAA and ICP-MS, were determined by the PGA. Altogether 43 elements were determined

  18. Activation Measurements for Thermal Neutrons, Part D. U.S. Measurements of 36Cl in Mineral Samples from Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    Tore Straume; Alfredo A, Marchetti; Stephen D, Egbert; James A, Roberts; Ping Men; Shoichiro Fujita; Kiyoshi Shizuma; Masaharu Hoshi; G, Rugel; W, Ruhm; G, Korschinek; J. E. McAninch; K. L. Carroll; T. Faestermann; K. Knie; R. E. Martinelli; A. Wallner; C. Wallner

    2005-01-01

    The present paper presents the 36 Cl measurement effort in the US. A large number of 36 Cl measurements have been made in both granite and concrete samples obtained from various locations and distances in Hiroshima and Nagasaki. These measurements employed accelerator mass spectrometry (AMS) to quantify the number of atoms of 36 Cl per atom of total Cl in the sample. Results from these measurements are presented here and discussed in the context of the DS02 dosimetry reevaluation effort for Hiroshima and Nagasaki atomic-bomb survivors. The production of 36 Cl by bomb neutrons in mineral samples from Hiroshima and Nagasaki was primarily via the reaction 35 Cl(n,γ) 36 Cl. This reaction has a substantial thermal neutron cross-section (43.6 b at 0.025 eV) and the product has a long half-life (301,000 y). hence, it is well suited for neutron-activation detection in Hiroshima and Nagasaki using AMS more than 50 years after the bombings. A less important reaction for bomb neutrons, 39 K(n,α) 36 Cl, typically produces less than 10% of the 36 Cl in mineral samples such as granite and concrete, which contain ∼ 2% potassium. In 1988, only a year after the publication of the DS86 final report (Roesch 1987), it was demonstrated experimentally that 36 Cl measured using AMS should be able to detect the thermal neutron fluences at the large distances most relevant to the A-bomb survivor dosimetry. Subsequent measurements in mineral samples from both Hiroshima and Nagasaki validated the experimental findings. The potential utility of 36 Cl as a thermal neutron detector in Hiroshima was first presented by Haberstock et al. who employed the Munich AMS facility to measure 36 Cl/Cl ratios in a gravestone from near the hypocenter. That work subsequently resulted in an expanded 36 Cl effort in Germany that paralleled the US work. More recently, there have also been 36 Cl measurements made by a Japanese group. The impetus for the extensive 36 Cl and other neutron activation

  19. Analysis of Cl, Mn, Na, Zn in Food Samples by a Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Jong Hwa; Kim, Sun Ha; Chung, Yong Sam [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Ok Hee [YongIn University, Yongin (Korea, Republic of)

    2008-10-15

    Due to their westernized dietary habit, Korean children are still threatened by the increasing risks of chronic disease such as obesity, hypertension, low immunity, etc. In addition, they are often exposed to a deficiency of Ca, Mg, Fe and micro-minerals which are necessary for their growth, immunity, and prevention of anemia. Nonetheless, the nutritional adequacy of mineral intakes for children is difficult to assess because of a lack of related studies and a nutritional database with respect to Korean children's foods. In this study, ninety kinds of foods consisting of lunch meals from an elementary and a middle school and children's favorite snacks were collected and prepared for an analysis. INAA which has an advantage of a non-destructive technique was employed to determine the elements like Cl, Mn, Na, Cl in the pretreated food samples. Quality control was carried out by using certified reference materials. From the analytical results, elemental concentration range in the collected samples according to the food groups was summarized.

  20. Analysis of Cl, Mn, Na, Zn in Food Samples by a Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Moon, Jong Hwa; Kim, Sun Ha; Chung, Yong Sam; Lee, Ok Hee

    2008-01-01

    Due to their westernized dietary habit, Korean children are still threatened by the increasing risks of chronic disease such as obesity, hypertension, low immunity, etc. In addition, they are often exposed to a deficiency of Ca, Mg, Fe and micro-minerals which are necessary for their growth, immunity, and prevention of anemia. Nonetheless, the nutritional adequacy of mineral intakes for children is difficult to assess because of a lack of related studies and a nutritional database with respect to Korean children's foods. In this study, ninety kinds of foods consisting of lunch meals from an elementary and a middle school and children's favorite snacks were collected and prepared for an analysis. INAA which has an advantage of a non-destructive technique was employed to determine the elements like Cl, Mn, Na, Cl in the pretreated food samples. Quality control was carried out by using certified reference materials. From the analytical results, elemental concentration range in the collected samples according to the food groups was summarized

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

    International Nuclear Information System (INIS)

    Almisned, Ghada

    2010-01-01

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

  2. Test of Fibre Bragg Gratings samples under High Fast Neutrons Fluence

    Directory of Open Access Journals (Sweden)

    Cheymol G.

    2018-01-01

    The measurements show that for nearly all gratings the Bragg peak remains visible after the irradiation, and that Radiation Induced Bragg Wavelength Shifts (RI-BWSs vary from few pm (equivalent to an error of less than 1°C for a temperature sensor to nearly 1 nm (equivalent to 100°C depending of the FBG types. High RI-BWSs could indeed be expected when considering the huge refractive index variation and compaction of the bare fibre samples that have been measured by other techniques. Post writing thermal annealing is confirmed as a key parameter in order to obtain a more radiation tolerant FBG. Our results show that specific annealing regimes allow making FGBs suitable to perform temperature measurements in a MTR experiment.

  3. Evaluation of lyophilization for the preconcentration of natural water samples prior to neutron activation analysis

    International Nuclear Information System (INIS)

    Harrison, S.H.; LaFleur, P.D.; Zoller, W.H.

    1975-01-01

    Water is preconcentrated by freeze drying using a method which virtually eliminates sample contamination and trace element losses. To test the possibility of losses of volatile elements during the drying process, known quantities of radioactive tracers for 21 elements were added to water, the solutions freeze dried, and the tracer residues counted. The results confirm that at least 95 percent of all but the most volatile elements studied (Hg and I) were retained in the residue. The problem of transferring quantitatively the dry residue from the freeze drying container to an irradiation container was eliminated by designing a freeze drying container that would also serve as an irradiation and counting container. (U.S.)

  4. Alpha-recoil tracks in natural dark mica: Dating geological samples by optical and scanning force microscopy

    International Nuclear Information System (INIS)

    Glasmacher, U.A.; Lang, M.; Klemme, S.; Moine, B.; Barbero, L.; Neumann, R.; Wagner, G.A.

    2003-01-01

    Alpha-recoil tracks (ART) are lattice defects caused by the α-decay of 238 U, 235 U, 232 Th, and daughter products. Visualization of etched ARTs in dark mica by phase-contrast microscopy allows dating of Quaternary geological as well as archaeological materials. Visualization of etched ARTs by Nomarski-differential-interference-contrast microscopy (NDICM) and scanning force microscopy (SFM) enables the access to areal densities (ρ a ) of ART etch pits beyond 10 4 mm -2 and thus the extension of the new ART-dating technique to an age range >1 Ma. The successful application of SFM as a new tool in geochronology could open the way to a field to be characterized as nanogeochronology. In order to visualize ARTs by NDICM and SFM, dark mica was etched with 4% HF at 21 deg. C for 5-107 min. A linear relationship between ρ a and etching time (t e ) was observed for phlogopites from the Kerguelen Islands (French territory, Indian Ocean), and the Kovdor magmatic complex (Russia). The volume density (ρ v ) of ART is a function of etching speed (v eff ) and slope of the ρ a -growth curve. The ART-age equation allows the calculation of an individual ρ v -growth curve for the phlogopite analysed by us using the uranium and thorium content. The ART-ages were determined by combining the experimentally obtained volume density with the individual ρ v -growth curve

  5. Prediction of the number of 14 MeV neutron elastically scattered from large sample of aluminium using Monte Carlo simulation method

    International Nuclear Information System (INIS)

    Husin Wagiran; Wan Mohd Nasir Wan Kadir

    1997-01-01

    In neutron scattering processes, the effect of multiple scattering is to cause an effective increase in the measured cross-sections due to increase on the probability of neutron scattering interactions in the sample. Analysis of how the effective cross-section varies with thickness is very complicated due to complicated sample geometries and the variations of scattering cross-section with energy. Monte Carlo method is one of the possible method for treating the multiple scattering processes in the extended sample. In this method a lot of approximations have to be made and the accurate data of microscopic cross-sections are needed at various angles. In the present work, a Monte Carlo simulation programme suitable for a small computer was developed. The programme was capable to predict the number of neutrons scattered from various thickness of aluminium samples at all possible angles between 00 to 36011 with 100 increments. In order to make the the programme not too complicated and capable of being run on microcomputer with reasonable time, the calculations was done in two dimension coordinate system. The number of neutrons predicted from this model show in good agreement with previous experimental results

  6. Determination of the provenance of obsidian samples collected in the archaeological site of San Miguel Ixtapan, Mexico State, Mexico by means of neutron activation analysis

    International Nuclear Information System (INIS)

    Almazan-Torres, M.G.; Aguirre-Martinez, P.I.

    2004-01-01

    Obsidian samples from San Miguel Ixtapan Mexico State, Mexico were analyzed by means of neutron activation. Statistical treatments such as bivariate, cluster and principal-components analyses were applied to the data set. Obsidians were identified as coming from three important sources: Sierra of Pachuca in the state of Hidalgo, Zinap uaro and Zin aro-Varal in the state of Michoacan. (author)

  7. Feasibility Study of Neutron Multiplicity Assay for a Heterogeneous Sludge Sample containing Na, Pu and other Impurities

    International Nuclear Information System (INIS)

    Nakamura, H.; Nakamichi, H.; Mukai, Y.; Yoshimoto, K.; Beddingfield, D.H.

    2010-01-01

    To reduce radioactivity of liquid waste generated at PCDF, a neutralization precipitation processes of radioactive nuclides by sodium hydroxide is used. We call the precipitate a 'sludge' after calcination. Pu mass in the sludge is normally determined by sampling and DA within the required uncertainty on DIQ. Annual yield of the mass is small but it accumulates and reaches to a few kilograms, so it is declared as retained waste and verified at PIV. A HM-5-based verification is applied for sludge verification. The sludge contains many chemical components. For example, Pu (-10wt%), U, Am, SUS components, halogens, NaNO 3 (main component), residual NaOH, and moisture. They are mixed together as an impure heterogeneous sludge sample. As a result, there is a large uncertainty in the sampling and DA that is currently used at PCDF. In order to improve the material accounting, we performed a feasibility study using neutron multiplicity assay for impure sludge samples. We have measured selected sludge samples using a multiplicity counter which is called FCAS (Fast Carton Assay System) which was designed by JAEA and Canberra. The PCDF sludge materials fall into the category of 'difficult to measure' because of the high levels of impurities, high alpha values and somewhat small Pu mass. For the sludge measurements, it was confirmed that good consistency between Pu mass in a pure sludge standard (PuO 2 -Na 2 U 2 O 7 , alpha=7) and the DA could be obtained. For unknown samples, using 14-hour measurements, we could obtain quite low statistical uncertainty on Doubles (-1%) and Triples (-10%) count rate although the alpha value was extremely high (15-25) and FCAS efficiency was relatively low (40%) for typical multiplicity counters. Despite the detector efficiency challenges and the material challenges (high alpha, low Pu mass, heterogeneous matrix), we have been able to obtain assay results that greatly exceed the accountancy requirements for retained waste materials. We have

  8. Determination of platinum, palladium, iridium and gold on selected geological reference materials by radiochemical neutron activation analysis: comparison of procedures based on aqua regia leaching and sodium peroxide sintering

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, C.A.; Figueiredo, A.M.G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1995-05-01

    A rapid and sensitive neutron activation method for the determination of platinum, palladium, iridium and gold in rocks is described. The procedure consists of thermal neutron irradiation of about 250 mg of sample, followed by chemical treatment of the rock, precipitation of gold and the platinum group elements with tellurium and high-resolution gamma-ray spectrometry with a hyper-pure Ge detector. Two different methods were used for the chemical treatment of the rock: aqua regia leaching and sintering with sodium peroxide. The procedures were evaluated by analysis of the certified reference material SARM-7 and the reference material CHR-Pt+. (author).

  9. Determination of platinum, palladium, iridium and gold on selected geological reference materials by radiochemical neutron activation analysis: comparison of procedures based on aqua regia leaching and sodium peroxide sintering

    International Nuclear Information System (INIS)

    Nogueira, C.A.; Figueiredo, A.M.G.

    1995-01-01

    A rapid and sensitive neutron activation method for the determination of platinum, palladium, iridium and gold in rocks is described. The procedure consists of thermal neutron irradiation of about 250 mg of sample, followed by chemical treatment of the rock, precipitation of gold and the platinum group elements with tellurium and high-resolution gamma-ray spectrometry with a hyper-pure Ge detector. Two different methods were used for the chemical treatment of the rock: aqua regia leaching and sintering with sodium peroxide. The procedures were evaluated by analysis of the certified reference material SARM-7 and the reference material CHR-Pt+. (author)

  10. Activation Measurements for Thermal Neutrons, U.S. Measurements of 36Cl in Mineral Samples from Hiroshima and Nagasaki; and Measurement of 63 Ni in Copper Samples From Hiroshima by Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tore Straume; Alfredo A. Marchetti; Stephen D. Egbert; James A. Roberts; Ping Men; Shoichiro Fujita; Kiyoshi Shizuma; Masaharu Hoshi; G. Rugel; W. Ruhm; G. Korschinek; J. E. McAninch; K. L. Carroll; T. Faestermann; K. Knie; R. E. Martinelli; A. Wallner; C. Wallner

    2005-01-14

    The present paper presents the {sup 36}Cl measurement effort in the US. A large number of {sup 36}Cl measurements have been made in both granite and concrete samples obtained from various locations and distances in Hiroshima and Nagasaki. These measurements employed accelerator mass spectrometry (AMS) to quantify the number of atoms of {sup 36}Cl per atom of total Cl in the sample. Results from these measurements are presented here and discussed in the context of the DS02 dosimetry reevaluation effort for Hiroshima and Nagasaki atomic-bomb survivors. The production of {sup 36}Cl by bomb neutrons in mineral samples from Hiroshima and Nagasaki was primarily via the reaction {sup 35}Cl(n,{gamma}){sup 36}Cl. This reaction has a substantial thermal neutron cross-section (43.6 b at 0.025 eV) and the product has a long half-life (301,000 y). hence, it is well suited for neutron-activation detection in Hiroshima and Nagasaki using AMS more than 50 years after the bombings. A less important reaction for bomb neutrons, {sup 39}K(n,{alpha}){sup 36}Cl, typically produces less than 10% of the {sup 36}Cl in mineral samples such as granite and concrete, which contain {approx} 2% potassium. In 1988, only a year after the publication of the DS86 final report (Roesch 1987), it was demonstrated experimentally that {sup 36}Cl measured using AMS should be able to detect the thermal neutron fluences at the large distances most relevant to the A-bomb survivor dosimetry. Subsequent measurements in mineral samples from both Hiroshima and Nagasaki validated the experimental findings. The potential utility of {sup 36}Cl as a thermal neutron detector in Hiroshima was first presented by Haberstock et al. who employed the Munich AMS facility to measure {sup 36}Cl/Cl ratios in a gravestone from near the hypocenter. That work subsequently resulted in an expanded {sup 36}Cl effort in Germany that paralleled the US work. More recently, there have also been {sup 36}Cl measurements made by a Japanese

  11. Determination of gold, indium, tellurium and thallium in the same sample digest of geological materials by atomic-absorption spectroscopy and two-step solvent extraction

    Science.gov (United States)

    Hubert, A.E.; Chao, T.T.

    1985-01-01

    A rock, soil, or stream-sediment sample is decomposed with hydrofluoric acid, aqua regia, and hydrobromic acid-bromine solution. Gold, thallium, indium and tellurium are separated and concentrated from the sample digest by a two-step MIBK extraction at two concentrations of hydrobromic add. Gold and thallium are first extracted from 0.1M hydrobromic acid medium, then indium and tellurium are extracted from 3M hydrobromic acid in the presence of ascorbic acid to eliminate iron interference. The elements are then determined by flame atomic-absorption spectrophotometry. The two-step solvent extraction can also be used in conjunction with electrothermal atomic-absorption methods to lower the detection limits for all four metals in geological materials. ?? 1985.

  12. Method Comparison of Neutron Activation Analysis and Atomic Absorption Spectrometry for Determination of Zinc in Food Samples

    International Nuclear Information System (INIS)

    Endah Damastuti; Syukria Kurniawati; Natalia Adventini

    2009-01-01

    Zinc as a micro nutrient, has important roles in human metabolism system. It is required by the body in appropriate amount from food intake. Due to the very low concentration of Zinc in food, high selectivity and sensitivity analysis technique is required for the determination, such as Neutron Activation Analysis (NAA) and Atomic Absorption Spectrometry (AAS). In this experiment, both methods were compared in zinc analysis of food samples. The subject of this experiment is to examine of those methods conformity and improving the technique capability in zinc analysis in food sample. Those methods were validated by analyzing zinc in SRM NIST 1548a Typical Diet and were tested its accuracy and precision. The results of Zn concentration were 25.1 ± 2.14 mg/kg by NAA and 24.1 ± 1.40 mg/kg by AAS while the certificate value was 24.6 ± 1.80 mg/kg. Percentage of relative bias, %CV, μ-test score and HORRAT(Horwitz ratio) value given by NAA were 2%, 8.5%, 0.18 and 0.9 respectively, while %relative bias, %CV, μ-test score and HORRAT value given by AAS were 2%, 5.8 %, 0.20 and 0.6 respectively. The result obtained for Zn concentration in various food samples by NAA and AAS were varied from 13.7 – 29.3 mg/kg with mean value 19.8 mg/kg and 11.2 – 26.0 mg/kg with mean value 17.3 mg/kg (author)

  13. A simple and rapid method for the determination of iodine in rice samples by radiochemical neutron activation analysis

    International Nuclear Information System (INIS)

    Takagi, Hiroyuki; Kimura, Toshimasa; Iwashima, Kiyoshi; Yamagata, Noboru.

    1983-01-01

    A simple and rapid method has been developed for the determination of iodine in rice samples by radiochemical neutron activation analysis. Irradiated rice powder was decomposed together with an iodide carrier solution containing I-131 on heating in a sodium hypochlorite solution. After decomposition, the solution was acidified with hydrochloric acid, and the insoluble residue was filtered off. To the filtrate sodium sulfite solution and palladium chloride solution were added, and the precipitate of palladium iodide was separated with a glass fiber filter paper. Iodine contents of rice were calculated from the peak areas under the 443 keV γ-ray of I-128 in the precipitate and comparative stand ard. Corrections for the chemical recovery were applied to them by means of the areas under the 365 keV γ-ray of I-131. This method was applied to the certified refe rece materials, IAEA wheat flour RM-V-5 and NBS orchard leaves SRM 1571. The results were in good agreement with the recommended values. Iodine contents of rice samples of two different origins in Japan were found to be of the order of 10 0 ng g -1 (dry weight base). The recovery of iodine in this procedure was about 80%. Decontamination factors for Mn, Cl, Na, and Br in the final fraction were 7 x 10 3 , 2 x 10 4 , 3 x 10 4 , and 2 x 10 2 , respectively. The time required for the chemical procedure was about 15 min, and the limit of determination was 0.7 ng of iodine in a sample of 1 g. (author)

  14. Radiocarbon dating of samples for archaeologic and geologic interesting by liquid scintillation spectrometry with low background radiation

    International Nuclear Information System (INIS)

    Pessenda, L.C.R.; Camargo, P.B. de

    1991-01-01

    An analytical system for radiocarbon dating of environmental samples using low level liquid scintillation counting spectrometry was developed at the Center for Nuclear Energy in Agriculture, University of Sao Paulo. Physical and chemical pretreatment and benzene synthesis of samples, counting procedure, optimization of analytical parameters and laboratory intercomparison with radiocarbon laboratories of Center for Applied Isotope Studies, University of Georgia, USA and University of Waterloo, Canada, are described. (author)

  15. The study of 90 deg. gamma ray production cross sections for interactions of 14.9 Mev neutrons with C, Al, V, Fe, Co, Nb samples

    International Nuclear Information System (INIS)

    Tang Lin; Yan Yiming; Zhou Hongyu; Wen Shenlin; Wang Qi; Sun Shuxu; Ding Xiaoji; Wang Wanhong

    1987-04-01

    The (n,xr) reactions have been studied for incident neutron energy 14.9 Mev and for the samples C, Al, V, Fe, Co and Nb. The pulsed beam Time-of-Flight technique was adopted to discriminate neutrons and de-excitation r-rays and to improve the background conditions of the experiment. 90 deg. differential gamma production cross sections as the results of experiments are presented. Due to very low background many new r-rays peaks have been obtained. (author). 14 refs, 12 figs, 1 tab

  16. Neutron radiography

    International Nuclear Information System (INIS)

    Alaa eldin, M.T.

    2011-01-01

    The digital processing of the neutron radiography images gives the possibility for data quantification. In this case an exact relation between the measured neutron attenuation and the real macroscopic attenuation coefficient for every point of the sample is required. The assumption that the attenuation of the neutron beam through the sample is exponential is valid only in an ideal case where a monochromatic beam, non scattering sample and non background contribution are assumed. In the real case these conditions are not fulfilled and in dependence on the sample material we have more or less deviation from the exponential attenuation law. Because of the high scattering cross-sections of hydrogen (σs=80.26 barn) for thermal neutrons, the problem with the scattered neutrons at quantitative radiography investigations of hydrogenous materials (as PE, Oil, H 2 O, etc) is not trivial. For these strong scattering materials the neutron beam attenuation is no longer exponential and a dependence of the macroscopic attenuation coefficient on the material thickness and on the distance between the sample and the detector appears. When quantitative radiography (2 D) or tomography investigations (3 D) are performed, some image correction procedures for a description of the scattering effect are required. This thesis presents a method that can be used to enhance the neutron radiography image for objects with high scattering materials like hydrogen, carbon and other light materials. This method uses the Monte Carlo code, MCNP5, to simulate the neutron radiography process and get the flux distribution for each pixel of the image and determine the scattered neutrons distribution that causes the image blur and then subtract it from the initial image to improve its quality.

  17. Investigation of (n, 2n) reaction and fission rates in iron-shielded uranium samples bombarded by 14.9 MeV neutrons

    International Nuclear Information System (INIS)

    Shani, G.

    1976-01-01

    The effect of the thickness of iron shielding on the (n, 2n) reaction rate in a fusion reactor (hybrid) blanket is investigated. The results are compared with the fission rate-dependence. Samples of natural uranium are irradiated with 14 MeV neutrons, with iron slabs of various thickness between the neutron generator target and the samples. Both reactions are threshold reactions but the fact that the 238 U (n, 2n) reaction threshold is at 6 MeV and that of fission is at 2 MeV makes the ratio between the two very much geometry-dependent. Two geometrical effects take place, the 1/r 2 and the build-up. While the build-up affects the (n, 2n) reaction rate, the fission rate is affected more by the 1/r 2 effect. The reason is that both elastic and inelastic scattering end up with neutrons with energy above fission threshold, while only elastic scattering brings high energy neutrons to the sample and causes (n, 2n) reaction. A comparison is made with calculated results where the geometrical effects do not exist. (author)

  18. Neutron activation analysis: principle and methods

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  19. Determination of vanadium in steel and geological samples by its extraction and spectrophotometric determination using 2,3-dihydroxynaphthalene

    International Nuclear Information System (INIS)

    Mondal, R.K.; Tarafder, P.K.; Rathore, D.P.S.

    2013-01-01

    A new and simple method for extraction and spectrophotometric determination of vanadium has been described. Iron has been removed from the sample solution by its prior extraction with MIBK from concentrated HCl medium (∼6 M). Vanadium has been determined in the form of a colored complex with 2,3-dihydroxynaphthalene after its extraction into MIBK. The method is at least 5 fold more sensitive to BPHA method. The molar absorptivity of the complex at 530 nm being 1.5 x 10 4 Lmol -1 cm -1 . For samples having >5 fold excess concentration of TiO 2 , a prior separation of TiO 2 as its (Ti (OH) (HND) 3 ) complex is a must. The method has been successfully applied to different rock, soil and steel samples. (author)

  20. Determination of As by instrumental neutron activation analysis in sectioned hair samples for forensic purposes: chronic or acute poisoning?

    International Nuclear Information System (INIS)

    Kucera, J.; Kofronova, K.

    2011-01-01

    Autopsy of 29-year old woman suspicious of committing suicide by the ingestion of As 2 O 3 yielded contradictory findings. All pathological findings as well as clinical symptoms suggested acute poisoning, while a highly elevated As level of 26.4 μg g -1 in her hair collected at the autopsy, which was determined with inductively coupled plasma mass spectrometry indicated chronic poisoning. To elucidate this discrepancy, instrumental neutron activation analysis (INAA) with proven accuracy was performed of another set of sectioned hair samples. Levels of As found by INAA in the range of 0.16-0.26 μg g -1 excluded chronic poisoning, because the person died after approximately 14 h after the As 2 O 3 ingestion. Two reasons for the discordant As results obtained by ICP-MS and INAA are considered: (1) accidental, non-removed contamination of hair on the As 2 O 3 ingestion; (2) erroneous performance of ICP-MS. (author)