Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
木村 敦
核データニュース(インターネット), (118), p.36 - 42, 2017/10
欧州原子核研究機構(CERN)にあるn_TOF実験施設において、Research Centre for Energy, Environment and Technology (CIMAT)と共同代表としてCm-244,246の中性子捕獲断面積測定研究を進めており、2017年夏n_TOF実験施設で測定実験を行った。本稿では堅苦しい学術的な話ではなく、読者の広場だからこそ書けるn_TOF実験施設での実験の様子や訪問の際に知っていれば便利だと思うことを紹介する。
Gunsing, F.*; 原田 秀郎; 木村 敦; n_TOF Collaboration*; 他141名*
European Physical Journal Plus (Internet), 131(10), p.371_1 - 371_13, 2016/10
被引用回数:29 パーセンタイル:59.28(Physics, Multidisciplinary)Nuclear data in general, and neutron-induced reaction cross sections in particular, are important for a wide variety of research fields. They play a key role in the safety and criticality assessment of nuclear technology, not only for existing power reactors but also for radiation dosimetry, medical applications, the transmutation of nuclear waste, accelerator-driven systems, fuel cycle investigations and future reactor systems as in Generation IV. Applications of nuclear data are also related to research fields as the study of nuclear level densities and stellar nucleosynthesis. Simulations and calculations of nuclear technology applications largely rely on evaluated nuclear data libraries. The evaluations in these libraries are based both on experimental data and theoretical models. CERN's neutron time-of-flight facility, n_TOF, has produced a considerable amount of experimental data since it has become fully operational with the start of the scientific measurement program in 2001. While for a long period a single measurement station (EAR1) located at 185 m from the neutron production target was available, the construction of a second beam line at 20 m (EAR2) in 2014 has substantially increased the measurement capabilities of the facility. An outline of the experimental nuclear data activities at n_TOF will be presented.
Barbagallo, M.*; Musumarra, A.*; Cosentino, L.*; Maugeri, E.*; Heinitz, S.*; Mengoni, A.*; Dressler, R.*; Schumann, D.*; Kppeler, F.*; 原田 秀郎; et al.
Physical Review Letters, 117(15), p.152701_1 - 152701_7, 2016/10
被引用回数:85 パーセンタイル:94.8(Physics, Multidisciplinary)The energy-dependent cross section of the Be(He reaction, of interest for the so-called cosmological lithium problem in big bang nucleosynthesis, has been measured for the first time from 10 meV to 10 keV neutron energy. Coincidences between the two alpha particles have been recorded in two Si-Be-Si arrays placed directly in the neutron beam. The present results are consistent, at thermal neutron energy, with the only previous measurement performed in the 1960s at a nuclear reactor. The energy dependence reported here clearly indicates the inadequacy of the cross section estimates currently used in BBN calculations. Although new measurements at higher neutron energy may still be needed, the n_TOF results hint at a minor role of this reaction in BBN, leaving the long-standing cosmological lithium problem unsolved.