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片渕 竜也*; 岩本 修; 堀 順一*; 木村 敦; 岩本 信之; 中村 詔司; Rovira Leveroni, G.; 遠藤 駿典; 芝原 雄司*; 寺田 和司*; et al.
EPJ Web of Conferences, 281, p.00014_1 - 00014_4, 2023/03
Long-lived minor actinides (MA) in nuclear waste from nuclear power plants are a long-standing issue to continue nuclear energy production. To solve the issue, researchers have suggested nuclear transmutation, in which long-lived radionuclides are transmuted into stable or shorter-life nuclides via neutron-induced nuclear reactions. Development of nuclear transmutation systems as an accelerator-driven system requires accurate neutron nuclear reaction data. The present research project entitled "Study on accuracy improvement of fast-neutron capture reaction data of long-lived MAs for development of nuclear transmutation systems" have been conducted as a joint collaboration, including Tokyo Tech, Japan Atomic Energy Agency and Kyoto University. This project focuses on the neutron capture reaction of MAs, especially 
Np, 
Am and 
Am, in the fast neutron energy region. The final goal of this project is to improve the accuracies of the neutron capture cross sections of Np, Am and Am employing a high-intensity neutron beam from a spallation source of the Japan Proton Accelerator Research Complex (J-PARC) that reduces uncertainties of measurement. To achieve the goal, a neutron beam filter system in J-PARC, sample characteristic assay, and theoretical reaction model study were developed. In this contribution, the overview and results of the project will be presented.
NpRovira Leveroni, G.; 片渕 竜也*; 登坂 健一*; 松浦 翔太*; 児玉 有*; 中野 秀仁*; 岩本 修; 木村 敦; 中村 詔司; 岩本 信之
Journal of Nuclear Science and Technology, 59(1), p.110 - 122, 2022/01
被引用回数：3 パーセンタイル：45.99(Nuclear Science & Technology)Neutron capture cross-section measurements for Np have been conducted with the Accurate Neutron Nucleus Reaction Measurement Instrument (ANNRI) at the Materials and Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC) using neutrons with energy ranging from thermal energy to 1 MeV. A Time of Flight (TOF) method using a NaI(Tl) detector was employed for these measurements and the data were analyzed based on the pulse-height weighting technique in order to derive the neutron capture cross-section. The absolute capture cross-section was determined using the whole shape of the first resonance from JENDL-4.0 together with the total neutron flux derived from a 
Au sample measurement in which the first resonance was completely saturated. Both normalization techniques present agreement within 2%. The present results are also compared evaluated data libraries. There is a discrepancy of 10-25% discrepancy from 0.5 to 20 keV with JENDL-4.0. Nonetheless, above this energy, the JENDL-4.0 seems to reproduce the present data better as the results agree within uncertainties up to 500 keV. The cross-section results contain errors below 4% from 0.5 to 30 keV. However, the total uncertainty increases to over 8% over that energy. Along with the cross section measurement, theoretical calculations were performed to reproduce the present results.
中野 翔太*; 紺野 壮見*; 富田 直人*; 松葉 豪*; 富永 大輝*; 高田 慎一
Microsystem Technologies, 22(1), p.57 - 63, 2016/01
被引用回数：3 パーセンタイル：21.01(Engineering, Electrical & Electronic)J-PARC-MLFの小角・広角中性子散乱法および光透過率法を用いて、ポリアクリルニトリルのゲル化構造形成過程における水分子の影響に関する研究を行った。その結果、ジメチルスルホキシド(DMSO)溶媒中の水分子の増加により、相分離およびゲル化が促進されることがわかった。白濁したゲルの場合、ナノメータスケールの結晶化による架橋点相関および液-液相分離によるミクロスケールの平坦境界が観測され、その相関長はアニーリング時間に依存しないこと、架橋点は局所的に存在しミクロゲルが形成されていることがわかった。一方、透明なゲルの場合は、相関長がゲル化過程において上昇し、高分子鎖の絡まり合いが擬似的な架橋点として作用していることがわかった。
