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-ray analysisHuang, M.; 藤 暢輔; 海老原 充*; 木村 敦; 中村 詔司
Journal of Applied Physics, 121(10), p.104901_1 - 104901_7, 2017/03
被引用回数：2 パーセンタイル：9.81(Physics, Applied)A new analytical technique, time-of-flight prompt -ray analysis, has been developed at the Japan Proton Accelerator Research Complex. In order to apply it to accurate elemental analysis, a set of standard Fe and Au samples were measured to examine the factors which affect the number of detected events. It was found that the main contributing factors included the attenuations of neutrons and rays in the sample, live-time ratio of the data acquisition system and signal pile-up correction factor. A simulation model was built for the estimations of neutron and -ray attenuations. A simple empirical formula was proposed to calculate the signal pile-up correction factor. The whole correction method has proven to be accurate and reliable.
線分析法土屋 晴文; 原田 秀郎; 小泉 光生; 北谷 文人; 呉田 昌俊; Becker, B.*; Kopecky, S.*; Heyse, J.*; Paradela, C.*; Mondelaers, W.*; et al.
核物質管理学会(INMM)日本支部第36回年次大会論文集(インターネット), 9 Pages, 2015/12
粒子状の溶融燃料デブリに含まれるウランやプルトニウム同位体を非破壊で定量することを目的に、中性子共鳴濃度分析法(NRD)の技術開発を進めてきた。NRDは、中性子共鳴透過分析法(NRTA)に中性子共鳴捕獲線分析法(NRCA)、あるいは即発線分析法(PGA)を組み合わせた技術である。NRDにおけるNRCA/PGAの役割は、主に
Csによる高放射線場においてデブリ中の原子炉や建屋の構造材、ボロンなどの不純物を同定することである。これを実現するため、LaBr
結晶を用いた新型の線検出器やそれ専用の遮蔽体を開発した。これらの線検出器や遮蔽体を用いて、ベルギーの中性子飛行時間施設GELINAにおいて公開デモ実験を実施した結果、第三者によってブラックボックス内に密封された試料(Hf, Gd, Ni)を同定することに成功した。本発表では、開発した線検出器の設計概念と測定原理、及びNRCAデモ実験結果について報告する。
河裾 厚男; 岡田 漱平
Japanese Journal of Applied Physics, Part 1, 36(2), p.605 - 611, 1997/00
被引用回数：5 パーセンタイル：32.62(Physics, Applied)電子線照射によってp型シリコン中に生成する電気的に中性な複空孔に起因する陽電子捕獲の温度効果を5.5Kから210Kの範囲で決定した。従来、複空孔の荷重状態が中性である場合、陽電子捕獲率は温度依存性を持たないと考えられていた。本研究では、複空孔の荷重状態を電子スピン共鳴の吸収、赤外吸収及びホール効果測定によって多重に確認した。実験の結果、複空孔の荷重状態が中性のときでも、陽電子捕獲率が極めて強い温度依存性を持つことが判明した。即ち、温度低下により捕獲率は増大し、30K付近にピークを示し、再び15K以下で増加することが見い出された。この振舞いは、従来提唱されていた陽電子捕獲の理論モデルからは、説明されない。我々は、それが共鳴現象に対するBreite-Wignerの一準位公式によりよく再現されることを見い出した。これより、中性の複空孔は、陽電子に対して共鳴準位を持つと考えられる。
-ray analysis at ANNRIHuang, M.; 藤 暢輔; 海老原 充*; 木村 敦; 中村 詔司
no journal, ,
The Accurate Neutron-Nucleus Reaction measurement Instrument has been available for time-of-flight (TOF) prompt -ray analysis. However, the specific relationship between the number of detected events and the sample weight is not entirely clear. In this study, a set of standard Fe and Ag samples were measured to investigate the factors which affect the counts and TOF counts. It is found that live time of acquisition (
), data acquisition efficiency in live time (
), neutron attenuation (NA) and -ray attenuation (GA) are the main contributing factors. An empirical formula is proposed for the calibration of . Simulation models are built for the evaluations of NA and GA by the PHITS program. The values of corrected and TOF counts are simply proportional to the sample weight. An accuracy of typically 5% has been achieved for the corrected result of a standard sample. It is sufficient for quantitative analysis.
-ray analysis at ANNRIHuang, M.; 藤 暢輔; 海老原 充*; 木村 敦; 中村 詔司
no journal, ,
The J-PARC Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) has been available for the time-of-flight (TOF) prompt -ray analysis. However, it is not entirely clear on the specific relationship between the number of detected events and the sample weight. In this study, a set of standard Fe and Ag samples were measured to examine the factors which affect the counts and TOF counts. It is found that the main contributing factors are live-time ratio of the data acquisition system (), data acquisition efficiency during the live time (), neutron attenuation (NA) and -ray attenuation (GA). A 5.3-kHz random-pulse generator is used for the determination of . is calibrated with an empirical formula. Simulation models are built for the evaluations of NA and GA by the PHITS program. With the present method, the values of corrected counts are accurately proportional to the sample weights.
Huang, M.; 藤 暢輔; 海老原 充*; 木村 敦; 中村 詔司
no journal, ,
Nickel-based super alloys are found in a wide range of applications, such as the manufacture of gas turbine military aircraft, power generation and marine propulsion. These kinds of alloys generally have complicated chemical compositions. In many studies, their compositions were determined by X-ray fluorescence (XRF) method since the alloys were not destroyed before testing their properties. However, XRF cannot detect the deep layer of alloys (typically under 0.1-mm depth). Therefore, thick alloys are hardly examined directly by XRF. Prompt gamma-ray analysis (PGA) and neutron resonance capture analysis (NCRA) are well-known non-destructive methods which are applicable to thick samples. Unfortunately, PGA is not very sensitive to some elements (e.g. Nb) and NCRA lacks of sensitivity to some light elements. At J-PARC ANNRI, the two methods have been combined as a new analytical method, TOF-PGA, which overcomes the disadvantages of PGA and NCRA. It is feasible to apply the new method to the examinations on materials with complicated chemical compositions. In this study, concentrations of Ni, Cr, Ti, Co, Al, B in two nickel-based super alloys were determined by PGA while W, Ta, Mo, Nb, Re, Ru and Hf were quantitatively analyzed by TOF analysis or TOF-PGA. The accurate results of present study show that the TOF-PGA technique is a powerful tool for the composition analysis on super alloys.
-ray analysis at ANNRIHuang, M.; 藤 暢輔; 海老原 充*; 木村 敦; 中村 詔司
no journal, ,
Prompt Gamma-ray Analysis (PGA) and neutron resonance capture analysis (NRCA) are well-known non-destructive methods for elemental determination. Their sensitivities and resolutions highly depend on elements. At J-PARC ANNRI, the two methods have been combined as a new analytical method, TOF-PGA. PGA, TOF and TOF-PGA spectra can be obtained simultaneously. Each element can be analyzed by the most suitable spectrum. However, the relationship between the number of detected events and the sample weight is not clear. In this study, a set of standard Fe, Ag and Au samples were measured to examine the factors which affect the -ray counts and TOF counts. It is found that the main contributing factors are live-time ratio of the data acquisition system (), signal pile-up correction factor (), neutron attenuation (NA) and -ray attenuation (GA). In this study, a 5.3-kHz random-pulse generator was used for the determination of . was calculated by an empirical formula which was calibrated with the PGA data of 5 g Fe. Simulation models were built for the evaluations of NA and GA by the PHITS program. The correction method was validated and used for the determination of chemical compositions of nickel-based super alloys.
