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Gilbert, M. R.*; 荒河 一渡*; 鈴土 知明; 都留 智仁; 他26名*
Journal of Nuclear Materials, 554, p.153113_1 - 153113_31, 2021/10
被引用回数：57 パーセンタイル：91.37(Materials Science, Multidisciplinary)核融合炉環境における材料性能の予測において、計算科学モデリングが重要な役割を果たしており、第一世代の核融合発電所が稼働し長期的な挙動の観察が可能になるまで継続することが予定されている。2019年に、主要な専門家のグループがIEAの傘下の会合に参加し、核融合材料のモデル化における現在の位置と進行中の課題、および高度な実験特性評価がモデルの改善にどのように役立つかについて議論した。本論文は、そのワークショップ中に行われた議論から得られたレビューとして報告するものである。照射誘発欠陥の生成と基本特性のモデリング、ガスの挙動、クラスタリング、欠陥成長と相互作用、新しいマルチスケールシミュレーション、および高度な実験によるモデリングと実験の連携に関する取り組みについて議論した。
-decay-correlated mass measurement of 
Ra using an -TOF detector equipped multireflection time-of-flight mass spectrograph system庭瀬 暁隆*; 伊藤 由太; 他26名*
Physical Review C, 104(4), p.044617_1 - 044617_8, 2021/10
被引用回数：6 パーセンタイル：57.44(Physics, Nuclear)The atomic masses of the isotopes 206,207Ra have been measured via decay-correlated mass spectroscopy using a multireflection time-of-flight mass spectrograph equipped with an -TOF detector. The Ra isotopes were produced as fusion-evaporation products in the 51V+159Tb reaction system and delivered by the gas-filled recoil ion separator GARIS-II at RIKEN. The -TOF detector provides for high-accuracy mass measurements by correlating time-of-flight signals with subsequent -decay events. The masses of 206Ra and 207g,mRa were directly measured using a multireflection time-of-flight mass spectrograph equipped with an -TOF detector. The mass excesses of 206,207gRa and the excitation energy of 207mRa were determined to be ME=3540(50)keV/c
, 3538(15)keV/c, and Eex=552(42) keV, respectively. The -decay branching ratio of 207mRa 
=0.26(20), was directly determined from decay-correlated time-of-flight signals, and the reduced width of 207mRa was calculated to be 
=43 keV from the branching ratio. The spin-parity of 207mRa was confirmed to be J
=13/2
from decay correlated mass measurement results.
AuHarding, R. D.*; Andreyev, A. N.; Barzakh, A. E.*; Cubiss, J. G.*; Van Duppen, P.*; Al Monthery, M.*; Althubiti, N. A.*; Andel, B.*; 他26名*
Physical Review C, 104(2), p.024326_1 - 024326_16, 2021/08
被引用回数：7 パーセンタイル：57.44(Physics, Nuclear)A detailed nuclear spectroscopy study of Au was performed at ISOLDE, CERN. This work provides new insights into the low-lying levels in the daughter nuclei 
Ir. For 
Au, the nuclear magnetic moments of a high spin and low spin state were determined and used to predict the most likely configuration of each level. Their -decay branching ratios were also extracted: a 58(5)% branching for the low-spin state, and 29(5)% for the high-spin state.
= 82 shell closureVaquero, V.*; Jungclaus, A.*; Rodr
guez-S
nchez, J. L.*; Tostevin, J. A.*; Doornenbal, P.*; Wimmer, K.*; Chen, S.*; Orlandi, R.; 他26名*
Physics Letters B, 795, p.356 - 361, 2019/08
被引用回数：5 パーセンタイル：41.18(Astronomy & Astrophysics)Inclusive one- and multi-nucleon removal cross sections were measured for several Sn, Sb and Te isotopes beyond the = 82 neutron shell closure at RIBF, RIKEN. The experimental cross sections are compared to predictions from the most recent Liege intranuclear cascade model. Severe discrepancies are observed and are discussed. Also, the measured inclusive one-proton knockout cross section for the semi-magic 
Sn projectile is compared to eikonal direct reaction theory calculations to assess if the suppression factors to these calculated cross sections are applicable to heavy nuclei.
Pu in the resonance region at the CERN n_TOF-EAR1 facilityLerendegui-Marco, J.*; Guerrero, C.*; Mendoza, E.*; Quesada, J. M.*; Eberhardt, K.*; Junghans, A. R.*; 木村 敦; n_TOF Collaboration*; 他126名*
Physical Review C, 97(2), p.024605_1 - 024605_21, 2018/02
被引用回数：25 パーセンタイル：85.39(Physics, Nuclear)This paper presents a new time-of-flight capture measurement on Pu carried out at n_TOF-EAR1(CERN), focusing on the analysis and statistical properties of the resonance region, below 4 keV. The Pu(n,
)reaction on a sample containing 95(4) mg enriched to 99.959% was measured with an array of four C
D detectors and applying the total energy detection technique. The high neutron energy resolution of n_TOF-EAR1 and the good statistics accumulated have allowed us to extend the resonance analysis up to 4 keV, obtaining new individual and average resonance parameters from a capture cross section featuring a systematic uncertainty of 5%, fulfilling the request of the NEA.
Pu(n,f) cross-section at the CERN n_TOF facility; First results from experimental area II (EAR-2)Stamatopoulos, A.*; Tsinganis, A.*; Colonna, N.*; 原田 秀郎; 木村 敦; n_TOF Collaboration*; 他126名*
EPJ Web of Conferences, 146, p.04030_1 - 04030_4, 2017/09
被引用回数：6 パーセンタイル：93.65(Nuclear Science & Technology)The accurate knowledge of the neutron-induced fission cross-sections of actinides and other isotopes involved in the nuclear fuel cycle is essential for the design of advanced nuclear systems, such as Generation-IV nuclear reactors. Such experimental data can also provide the necessary feedback for the adjustment of nuclear model parameters used in the evaluation process, resulting in the further development of nuclear fission models. In the present work, the Pu(n,f) cross-section was measured at CERN n_TOF facility relative to the well-known 
U(n,f) cross section, over a wide range of neutron energies, from meV to almost MeV, using the time-of-flight technique and a set-up based on Micromegas detectors. This measurement was the first experiment to be performed at n_TOF new experimental area (EAR-2), which offers a significantly higher neutron flux compared to the already existing experimental area (EAR-1).Preliminary results as well as the experimental procedure, including a description of the facility and the data handling and analysis, are presented.
S(n, )
Si cross section measurement at n_TOF-EAR2 (CERN); From 0.01 eV to the resonance regionSabat
-Gilarte, M.*; Praena, J.*; 原田 秀郎; 木村 敦; n_TOF Collaboration*; 他126名*
EPJ Web of Conferences, 146, p.08004_1 - 08004_4, 2017/09
被引用回数：5 パーセンタイル：91.33(Nuclear Science & Technology)CERNのn_TOF第2実験室において、
B(n,)を標準断面積として用い、S(n, )Si反応断面積を測定した。本実験室では初めてとなる0.01eVから100keVまでの実験データを取得し、本データより0.01eVから10keVまでの中性子断面積を導出した。本反応は、B(n, )反応とともに放射線療法への利用が期待されているが、従来報告された断面積値間には大きな差異がある。本研究により導出した断面積は、信頼性ある断面積評価に反映されることが期待される。
Be(n, ) reaction at n_TOFCosentino, L.*; Musumarra, A.*; Barbagallo, M.*; Pappalardo, A.*; 原田 秀郎; 木村 敦; n_TOF Collaboration*; 他126名*
Nuclear Instruments and Methods in Physics Research A, 830, p.197 - 205, 2016/09
被引用回数：20 パーセンタイル：83.51(Instruments & Instrumentation)The newly built second experimental area EAR2 of the n_TOF spallation neutron source at CERN allows to perform (n, charged particles) experiments on short-lived highly radioactive targets. This paper describes a detection apparatus and the experimental procedure for the determination of the cross-section of the Be(n, ) reaction, which represents one of the focal points toward the solution of the cosmological Lithium abundance problem, and whose only measurement, at thermal energy, dates back to 1963. This newly developed setup could likely be useful also to study other challenging reactions requiring the detectors to be installed directly in the neutron beam.
= 200 GeVAdare, A.*; 長谷川 勝一; 今井 憲一; 永宮 正治; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他426名*
Physical Review C, 93(3), p.034904_1 - 034904_29, 2016/03
被引用回数：44 パーセンタイル：92.43(Physics, Nuclear)The PHENIX Collaboration at the Relativistic Heavy Ion Collider has measured open heavy flavor production in minimum bias Au + Au collisions at = 200 GeV via the yields of electrons from semileptonic decays of charm and bottom hadrons. Previous heavy flavor electron measurements indicated substantial modification in the momentum distribution of the parent heavy quarks owing to the quark-gluon plasma created in these collisions. For the first time, using the PHENIX silicon vertex detector to measure precision displaced tracking, the relative contributions from charm and bottom hadrons to these electrons as a function of transverse momentum are measured in Au + Au collisions. We compare the fraction of electrons from bottom hadrons to previously published results extracted from electron-hadron correlations in 
collisions at = 200 GeV and find the fractions to be similar within the large uncertainties on both measurements for 
4 GeV/
. We use the bottom electron fractions in Au + Au and along with the previously measured heavy flavor electron 
to calculate the for electrons from charm and bottom hadron decays separately. We find that electrons from bottom hadron decays are less suppressed than those from charm for the region 3
4 GeV/.
Wei
, C.*; Chiaveri, E.*; Girod, S.*; Vlachoudis, V.*; 原田 秀郎; 木村 敦; n_TOF Collaboration*; 他126名*
Nuclear Instruments and Methods in Physics Research A, 799, p.90 - 98, 2015/11
被引用回数：83 パーセンタイル：98.83(Instruments & Instrumentation)At the neutron time-of-flight facility n_TOF at CERN a new vertical beam line was constructed in 2014, in order to extend the experimental possibilities at this facility to an even wider range of challenging cross-section measurements of interest in astrophysics, nuclear technology and medical physics. The design of the beamline and the experimental hall was based on FLUKA Monte Carlo simulations, aiming at maximizing the neutron flux, reducing the beam halo and minimizing the background from neutrons interacting with the collimator or back-scattered in the beam dump. The present paper gives an overview on the design of the beam line and the relevant elements and provides an outlook on the expected performance regarding the neutron beam intensity, shape and energy resolution, as well as the neutron and photon backgrounds.
安邊 啓明; 他26名*
no journal, ,
スタイロライトは、圧力溶解による脱水で形成される、複雑に指交した形状を示す岩石中の剥離構造であり、古応力の推定に有用である。スタイロライトの形成は蒸発岩堆積後の堆積空間の形成に寄与する可能性があることから、蒸発岩中のスタイロライト形成時の応力条件を明らかにすることが重要である。本研究では、2024年2月から4月にかけてイタリア沖のティレニア海で掘削されたIODP第402次航海コア試料中の蒸発岩に見られるスタイロライトを分析した。スタイロライトを写真撮影、トレースし、離散フーリエ変換法を用いて解析することで、異なる粗さ指数を持つ2つのスケーリング領域を分離する遷移長Lを推定した。多くのスタイロライトについてLは2mm程度だった。これに基づいて推定される応力値はコアの回収深度と整合的であることから、蒸発岩中のスタイロライトが応力の推定に有用であることが示唆された。
森下 知晃*; 安邊 啓明; 他26名*
no journal, ,
A nondestructive description of core samples obtained by drilling is an essential first step in understanding the record of the cored samples. Natural gamma radiation (NGR) emitted when 
K, 
U, and 
Th radioisotopes and their daughter products decay has been routinely measured by onboard equipment on the IODP drillship JOIDES Resolution since Expedition 317. NGR spectra show sufficient energy resolution to identify the major peaks of the isotope. International Ocean Discovery Program Expedition 402 drilled into the Central Vavilov Basin of the Tyrrhenian Sea, where the continental-ocean transition (COT) is exposed. Cores over 100 m long, consisting mainly of serpentinite, were recovered from two sites (U1614 and U1616). NGR variations in one of the serpentinite cores (Site 1614) were investigated and their implications were discussed. High NGRs above 20 cps appear to be associated with granitic rocks. We chose to focus only on variations in NGR below 20 cps. The total NGR aviation appears to be roughly consistent with the variation in the Uranium signal. Several very low NGR (
5 cps) intervals are observed in the core. These low NGR intervals are characterized by "homogeneous" serpentinite. One of the mineral phases that may contain uranium in serpentinite cores is carbonate minerals. Carbonate veins and replacement by carbonate minerals is observed heterogeneously in the core. In the presentation, we will introduce the relationships between chemical compositions of minerals and NGR spectra of representative core and evaluate NGR analysis in nondestructive description of serpentine cores.
