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Yee-Rendon, B.; Jameson, R. A.*; 岡村 昌宏*; Li, C.*; Jiang, P.*; Maus, J. M.*
Proceedings of 32nd Linear Accelerator Conference (LINAC 2024) (Internet), p.492 - 495, 2024/10
LINACsは、粒子加速器内の荷電粒子の光学系とビーム ダイナミクスを設計するためのシミュレーションのフレームワークであり、RFQのすべての設計パラメータとシミュレーションパラメータをユーザーが完全に制御できるオープンソースのフトウェアである。ビーム駆動設計、正確な四極対称性を使用した完全3Dシミュレーション、外部および空間電荷場に対する厳密なポアソン解を含む。本コードは、解析入力分布を伴う粒子ビームを同時に処理でき、入力ビームの状態がスキャン可能である。本ソフトウェアは実行時間が比較的短くかつ広範な分析情報を提供する。本発表では、コードの歴史的な概要を説明するとともにRFQモデルの結果を提示し、将来の開発について議論する。
Se from combined conversion-electron and 
-ray spectroscopySmallcombe, J.; Garnsworthy, A. B.*; Korten, W.*; Singh, P.*; Muir, D.*; Pr
chniak, L.*; Ali, F. A.*; Andreoiu, C.*; Ansari, S.*; Ball, G. C.*; et al.
Physical Review C, 110(2), p.024318_1 - 024318_16, 2024/08
被引用回数：0 パーセンタイル：0.00(Physics, Nuclear)In the selenium isotopes various shape phenomena are present, in particular the emergence of a dominant oblate deformation in the most neutron-deficient isotopes has been observed. The scenario of shape coexisting oblate and prolate bands has been proposed across the isotopic chain, with the crossing point of such bands being located near Se, where no coexistence has yet been identified. To determine the presence or absence of any low-lying 
state in Se, confirm the level structure, and interpret the nuclear deformation with theoretical models. A combined internal conversion electron and -ray spectroscopy study was undertaken with the SPICE and TIGRESS spectrometers at the TRIUMF-ISAC-II facility. Nuclear models were provided by the Generalised Triaxial Rotor Model (GTRM) and the collective Generalised Bohr Hamiltonian (GBH). Despite a comprehensive search, no evidence was found for the existence of a state below 2 MeV in Se. Significant discrepancies to the previously established positive parity level scheme were found. GBH calculations using UNEDF1 mass parameters were found to reproduce the revised low-lying level structure well. Se does not have a well defined axial shape. The 2
state at 1601 keV resembles a quasi- excitation rather than a member of a shape coexisting band; the presence of such a band is all but ruled out.
Li, X.*; Zhu, R.*; Xin, J.*; Luo, M.*; Shang, S.-L.*; Liu, Z.-K.*; Yin, C.*; 舟越 賢一*; Dippenaar, R. J.*; 肥後 祐司*; et al.
CALPHAD; Computer Coupling of Phase Diagrams and Thermochemistry, 84, p.102641_1 - 102641_6, 2024/03
被引用回数：0 パーセンタイル：0.00(Thermodynamics)The phase transformations and pressure-volume dependencies of the Ti-45Al alloy with respect to pressure have been investigated by means of in-situ observation using multi anvil-type high-pressure devices and synchrotron radiation. Under hydrostatic compression from 0 to 10.1 GPa, about 2.3 vol. % of transforms continuously to 
2. Lattice parameters as well as volume fractions of these two phases have been determined as a function of pressure. Bulk moduli estimated using Birch-Murnaghan's equation of state are 148 GPa for the phase, 138 GPa for the 2 phase, and 149 GPa for their two-phase mixture of Ti-45Al alloy. First-principles have also applied to investigate bulk moduli of two single phases, and the deviation between calculations and measurements is discussed and attributed to mainly phase transformation. The presently study provides useful insights into thermodynamics of 2 and phases under high pressure.
R
hm, W.*; 伴 信彦*; Chen, J.*; Li, C.*; Dobynde, M.*; Durante, M.*; El-Jaby, S.*; 込山 立人*; 小笹 晃太郎*; 佐藤 達彦; et al.
Journal of Medical Physics - Zeitschrift fr medizinische Physik -, 34(1), p.4 - 13, 2024/02
国際放射線防護委員会(ICRP)は、過去90年間に渡って世界各国や国際的な放射線防護の枠組み作りに貢献してきた。2019年、ICRPは宇宙飛行士の放射線防護に関わる様々な問題に対応したタスクグループ(TG115)を立ち上げ、地上の放射線防護体系と宇宙の放射線防護体系との共通の枠組み作りに取り組んでいる。本論文では、現時点でICRPが定めている宇宙放射線防護体系についてとりまとめて報告する。
Shavers, M. R.*; Semones, E. J.*; Shurshakov, V.*; Dobynde, M.*; 佐藤 達彦; 込山 立人*; Tomi, L.*; Chen, J.*; El-Jaby, S.*; Straube, U.*; et al.
Journal of Medical Physics - Zeitschrift fr medizinische Physik -, 34(1), p.31 - 43, 2024/02
本論文では、国際宇宙ステーションに協力している宇宙機関が、それぞれの評価方法で推定した宇宙線被ばく線量及びそのリスクを相互比較した結果を報告する。比較するミッションには、30日間の磁気圏外ミッションを選択し、宇宙線源として銀河宇宙線と太陽高エネルギー粒子の両方を考慮した。本比較結果より、各機関の線量・リスク評価方法に関する一貫性を確認することができた。本成果は、国際放射線防護委員会(ICRP)のタスクグループ115のレポートとして将来、まとめられる予定である。
-Ti alloyZhang, B.*; Xin, S.*; Huang, M.*; Mao, W.; Jia, W.*; Li, Q.*; Li, S.*; Zhang, S.*; Mao, C.*
Materials Science & Engineering A, 890, p.145898_1 - 145898_7, 2024/01
被引用回数：0 パーセンタイル：0.00(Nanoscience & Nanotechnology)本研究では、高Zr--Ti合金の変形温度を300Kから77Kに下げると回復ひずみが2.25%から5.5%に大幅に増加することを報告した。この合金の超弾性は77Kにおいて粒径に依存しないことがわかった。その結果、粗粒試料は77Kで超微粒試料とほぼ同じ超弾性を示すことがわかった。変形誘起マルテンサイト変態と転位すべりの相対的な容易さは77Kで大きく変化し、転位すべりは強く抑制され、超弾性に対する結晶粒の微細化の影響は影を潜めた。
Zhang, A.*; Deng, K.*; Sheng, J.*; Liu, P.*; Kumar, S.*; 島田 賢也*; Jiang, Z.*; Liu, Z.*; Shen, D.*; Li, J.*; et al.
Chinese Physics Letters, 40(12), p.126101_1 - 126101_8, 2023/12
被引用回数：6 パーセンタイル：84.64(Physics, Multidisciplinary)In a Dirac semimetal, the massless Dirac fermion has zero chirality, leading to surface states connected adiabatically to a topologically trivial surface state as well as vanishing anomalous Hall effect. Recently, itis predicted that in the nonrelativistic limit of certain collinear antiferromagnets, there exists a type of chiral "Dirac-like" fermion, whose dispersion manifests four-fold degenerate crossing points formed by spin-degenerate linear bands, with topologically protected Fermi arcs. Here, by combining with neutron diffraction and first-principles calculations, we suggest a multidomain collinear antiferromagnetic configuration, rendering the existence of the Fermi-arc surface states induced by chiral Dirac-like fermions.
O近藤 洋介*; Achouri, N. L.*; Al Falou, H.*; Atar, L.*; Aumann, T.*; 馬場 秀忠*; Boretzky, K.*; Caesar, C.*; Calvet, D.*; Chae, H.*; et al.
Nature, 620(7976), p.965 - 970, 2023/08
被引用回数：18 パーセンタイル：95.53(Multidisciplinary Sciences)非常に中性子が過剰な原子核Oは、陽子、中性子ともに魔法数であることから古くからその性質に興味が持たれていたが、酸素の最後の束縛核
Oよりも中性子が4個も多いため、これまで観測されてこなかった。この論文では、理化学研究所RIBFにて
Fからの1陽子ノックアウト反応によってOを生成し、そこから放出される中性子を測定することによって初めてその観測に成功した。核構造の観点からは、Oでは二重閉殻が保たれているか興味が持たれていたが、実験で得られた分光学的因子が殻模型計算で予言されて程度の大きいことから、閉殻構造をもたない可能性が高いことがわかった。
Ne at the transition into the island of inversion; Detailed structure study of NeWang, H.*; 安田 昌弘*; 近藤 洋介*; 中村 隆司*; Tostevin, J. A.*; 緒方 一介*; 大塚 孝治*; Poves, A.*; 清水 則孝*; 吉田 数貴; et al.
Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08
被引用回数：3 パーセンタイル：75.57(Astronomy & Astrophysics)Neからの1中性子除去反応を用いて、Neの詳細な線分光を行った。平行運動量分布の解析に基づき、Neの準位構造とスピンパリティを決定し、初めて負のパリティ状態を同定した。測定された断面積と運動量分布から、N=20とN=28のシェルギャップの消失の証拠となる有意なintruder p-wave強度が明らかになった。束縛状態については、弱いf-waveの可能性のある強度が観測された。いくつかの有効相互作用を用いた大規模殻模型計算では、実験的に観測された大きなp-wave強度と小さなf-wave強度は再現されず、Ne同位体に沿った反転の島への遷移の完全な理論的記述への挑戦が続いていることを示している。
Yuan, X.*; Hu, Q.*; Lin, X.*; Zhao, C.*; Wang, Q.*; 舘 幸男; 深津 勇太; 濱本 昌一郎*; Siitari-Kauppi, M.*; Li, X.*
Journal of Hydrology, 618, p.129172_1 - 129172_15, 2023/03
被引用回数：2 パーセンタイル：26.10(Engineering, Civil)Mass transport in geomedia as influenced by the pore structure is an important phenomenon. Six rocks (granodiorite, limestone, two chalks, mudstone, and dolostone) with different extents of heterogeneity at six different particle sizes were studied to describe the effects of pore connectivity on mass transport. The multiple methods applied were porosity measurement, gas diffusion test, and batch sorption test of multiple ions. Porosity measurement results reveal that with decreasing particle sizes, the effective porosities for the "heterogenous" group (granodiorite and limestone) increase, whereas the porosities of "homogeneous" group (chalks, mudstone, and dolostone) roughly remain constant. Gas diffusion results show that the intraparticle gas diffusion coefficient among these two groups, varying in the magnitude of 10
to 10
m
/s. The batch sorption work displays a different affinity of these rocks for tracers, which are related to their mineral components. For granodiorite, mudstone, and dolostone, the adsorption capacity increases as the particle size decreases, due to higher specific surface area in smaller particle-size. In general, this integrated research of grain size distribution, rock porosity, intraparticle diffusivity, and ionic sorption capacity gives insights into the pore connectivity effect on both gas diffusion and chemical transport behaviors for different lithologies and/or different particle sizes.
Jiang, X.*; 服部 高典; Xu, X.*; Li, M.*; Yu, C.*; Yu, D.*; Mole, R.*; 矢野 真一郎*; Chen, J.*; He, L.*; et al.
Materials Horizons, 10(3), p.977 - 982, 2023/03
被引用回数：17 パーセンタイル：94.23(Chemistry, Multidisciplinary)現在の蒸気圧縮式冷凍機に代わる環境に優しい冷凍機として、バロカロリック効果に基づく固体冷凍機が世界的に注目されている。一般に、バロカロリック効果が発現する相はいずれも常圧でも存在する。ここでは、それらの物質と違って、KPF
が高圧の菱面体晶相を生成することにより、巨大なバロカロリック効果を示すことを実証した。相図は、圧力依存の熱量測定、ラマン散乱測定、中性子回折測定に基づいて構築されたものである。本研究は、巨大バロカロリー効果に、高圧相の生成という新たな手法をもたらすと期待される。
Wei, D.*; Gong, W.; 都留 智仁; Lobzenko, I.; Li, X.*; Harjo, S.; 川崎 卓郎; Do, H.-S.*; Bae, J. W.*; Wagner, C.*; et al.
International Journal of Plasticity, 159, p.103443_1 - 103443_18, 2022/12
被引用回数：67 パーセンタイル：99.58(Engineering, Mechanical)Face-centered cubic single-phase high-entropy alloys (HEAs) containing multi-principal transition metals have attracted significant attention, exhibiting an unprecedented combination of strength and ductility owing to their low stacking fault energy (SFE) and large misfit parameter that creates severe local lattice distortion. Increasing both strength and ductility further is challenging. In the present study, we demonstrate via meticulous experiments that the CoCrFeNi HEA with the addition of the substitutional metalloid Si can retain a single-phase FCC structure while its yield strength (up to 65%), ultimate strength (up to 34%), and ductility (up to 15%) are simultaneously increased, owing to a synthetical effect of the enhanced solid solution strengthening and a reduced SFE. The dislocation behaviors and plastic deformation mechanisms were tuned by the addition of Si, which improves the strain hardening and tensile ductility. The present study provides new strategies for enhancing HEA performance by targeted metalloid additions.
La
Fe
Ni
As
Xie, T.*; Liu, C.*; 梶本 亮一; 池内 和彦*; Li, S.*; Luo, H.*
Journal of Physics; Condensed Matter, 34(47), p.474001_1 - 474001_8, 2022/11
被引用回数：0 パーセンタイル：0.00(Physics, Condensed Matter)We report time-of-flight inelastic neutron scattering (INS) investigations on the spin fluctuation spectrum in the 112-type iron-based superconductor (FeSC) CaLaFeNiAs (CaLa-112). In comparison to the 122-type FeSCs with a centrosymmetric tetragonal lattice structure (space group 
) at room temperature and an in-plane stripe-type antiferromagnetic (AF) order at low temperature, the 112 system has a noncentrosymmetric structure (space group 
) with additional zigzag arsenic chains between Ca/La layers and a magnetic ground state with similar wavevector 
but different orientations of ordered moments in the parent compounds. Our INS study clearly reveals that the in-plane dispersions and the bandwidth of spin excitations in the superconducting CaLa-112 closely resemble to those in 122 systems. While the total fluctuating moments 
/Fe are larger than 122 system, the dynamic correlation lengths are similar (
). These results suggest that superconductivity in iron arsenides may have a common magnetic origin under similar magnetic exchange couplings with a dual nature from local moments and itinerant electrons, despite their different magnetic patterns and lattice symmetries.
neutron diffraction and electron microscopy studyZheng, R.*; Gong, W.; Du, J.-P.*; Gao, S.*; Liu, M.*; Li, G.*; 川崎 卓郎; Harjo, S.; Ma, C.*; 尾方 成信*; et al.
Acta Materialia, 238, p.118243_1 - 118243_15, 2022/10
被引用回数：31 パーセンタイル：96.96(Materials Science, Multidisciplinary)Grain refinement can lead to the strengthening of metallic materials according to the Hall-Petch relationship. However, our recent results suggested that grain boundary sliding is the dominant deformation mode in bulk ultrafine grained (UFG) pure Mg at room temperature, leading to softening. Here, for the first time, we report that the Hall-Petch strengthening can be regained in bulk UFG pure Mg at cryogenic temperature. At 77K, the UFG pure Mg with a mean grain size of 0.6 
m exhibited ultrahigh tensile yield strength and ultimate tensile strength of 309 MPa and 380 MPa, respectively. Combined neutron diffraction and electron microscopy investigation indicated that residual dislocation structures and deformation twins hardly formed in the UFG specimen during tensile test at 298K. In contrast, fast accumulation of lattice defects and remarkable reorientation were evident at 77K, suggesting that the grain-boundary-mediated process was suppressed and the plastic deformation was dominated by dislocation slip and deformation twinning. In addition, all the pure Mg specimens exhibited pronounced strain hardening at 77 K, which was mainly attributed to the suppressed grain boundary sliding and dynamic recovery. The mean dislocation density and relative fractions of dislocations with various Burgers vectors of the UFG specimen deformed at 77K were determined quantitatively from neutron diffraction data.
0 transition strength for 
Se using the SPICE spectrometerSmallcombe, J.; Garnsworthy, A. B.*; Korten, W.*; Singh, P.*; Ali, F. A.*; Andreoiu, C.*; Ansari, S.*; Ball, G. C.*; Barton, C. J.*; Bhattacharjee, S. S.*; et al.
Physical Review C, 106(1), p.014312_1 - 014312_9, 2022/07
被引用回数：5 パーセンタイル：70.77(Physics, Nuclear)The selenium isotopes lie at the heart of a tumultuous region of the nuclear chart where shape coexistence effects grapple with neutron-proton pairing correlations, triaxiality, and the impending proton dripline. In this work a study of Se by internal conversion electron and -ray spectroscopy was undertaken with the SPICE and TIGRESS arrays. New measurements of the branching ratio and lifetime of the 
state were performed yielding a determination of 
milliunits. Two state mixing calculations were performed that highlighted the importance of interpretation of such 
strength values in the context of shape-coexistence.
Liu, M.*; Gong, W.; Zheng, R.*; Li, J.*; Zhang, Z.*; Gao, S.*; Ma, C.*; 辻 伸泰*
Acta Materialia, 226, p.117629_1 - 117629_13, 2022/03
被引用回数：61 パーセンタイル：99.37(Materials Science, Multidisciplinary)One hopeful path to realize good comprehensive mechanical properties in metallic materials is to accomplish homogeneous nanocrystalline (NC) or ultrafine grained (UFG) structure with low dislocation density. In this work, high pressure torsion deformation followed by appropriate annealing was performed on 316 stainless steel (SS). For the first time, we successfully obtained NC/UFG 316 SS having uniform microstructures with various average grain sizes ranging from 46 nm to 2.54 m and low dislocation densities. Among the series, an un-precedentedly high yield strength (2.34 GPa) was achieved at the smallest grain size of 46 nm, in which dislocation scarcity induced hardening accounting for 57% of the strength. On the other hand, exceptional strength-ductility synergy with high yield strength (900 MPa) and large uniform elongation (27%) was obtained in the fully recrystallized specimen having the grain size of 0.38 m. The high yield stress and scarcity of dislocation sources in recrystallized UFGs activated stacking faults and deformation twins nucleating from grain boundaries during straining, and their interaction with dislocations allowed for sustainable strain hardening, which also agreed with the plaston concept recently proposed. The multiple deformation modes activated, together with the effective strengthening mechanisms, were responsible for the outstanding comprehensive mechanical performance of the material.
BiDoherty, D. T.*; Andreyev, A. N.; Seweryniak, D.*; Woods, P. J.*; Carpenter, M. P.*; Auranen, K.*; Ayangeakaa, A. D.*; Back, B. B.*; Bottoni, S.*; Canete, L.*; et al.
Physical Review Letters, 127(20), p.202501_1 - 202501_6, 2021/11
被引用回数：10 パーセンタイル：66.31(Physics, Multidisciplinary)Bi is the heaviest known proton emitting isotope. Its decay had been observed, but the assumed ground-state lifetime (
s) was incorrect, leading to unexplained hindrance. With two new experiments at Argonne National Laboratory, two states were clearly identified. One is the proton-emitting ground-state (spin 1/2
, half-life: 2.8
s), the second is a 58(2) s -decaying isomer. The new data show the inversion of the ground and isomeric states compared to neighboring Bi isotopes. This is the only known example of a ground-state proton decay to a daughter nucleus (
Pb) with a major shell closure.
Unc, A.*; Altdorff, D.*; Abakumov, E.*; Adl, S.*; Baldursson, S.*; Bechtold, M.*; Cattani, D. J.*; Firbank, L. G.*; Grand, S.*; Gudjonsdottir, M.*; et al.
Frontiers in Sustainable Food Systems (Internet), 5, p.663448_1 - 663448_11, 2021/07
被引用回数：41 パーセンタイル：93.03(Food Science & Technology)本レビュー論文では、関連分野を研究する科学者の意識調査と既存文献の調査を実施し、地球温暖化の加速が寒冷な北方地域を地域および世界の農業セクター拡大にとってますます魅力的なターゲットにしていることを明らかにした。ただし、こうした活動の持続可能な長期的発展は、信頼性のある関連知見に対し全てのステークホルダーが容易にアクセスできる場合にのみ実現できる、という共通認識があることも明らかになった。特に、北方地域における農業の拡大は、温室効果ガス収支や生物多様性、生態系サービスに対し、負の影響をもたらす傾向にあることが明らかになってきている。以上より、寒冷な北方地域における農業の拡大と強化は、社会的な向上とニュートラルな環境影響とを両立できる計画の下で遂行される必要がある。
Dimitriou, P.*; Dillmann, I.*; Singh, B.*; Piksaikin, V.*; Rykaczewski, K. P.*; Tain, J. L.*; Algora, A.*; Banerjee, K.*; Borzov, I. N.*; Cano-Ott, D.*; et al.
Nuclear Data Sheets, 173, p.144 - 238, 2021/03
被引用回数：27 パーセンタイル：95.10(Physics, Nuclear)核分裂の発見以降、核分裂片から放出される遅発中性子の存在には、数多くの関心が集められてきた。原子力発電では、遅発中性子は原子炉動特性の計算や炉の安全運転において非常に重要な役割を演じている。それに加え、遅発中性子は、核構造や天体核、特に新世代のRIビーム施設の中心課題である安定線から離れた原子核でも、大きなインパクトをもっている。現在、ベータ崩壊半減期と遅発中性子分岐比に関するいくつかの文献が利用可能であるが、測定と評価によって実施されるべき十分な考証は、それらの文献ではしばしば抜けている。この欠落部に注目し、遅発中性子の核データ評価とそれに関する新しい文献作成の作業が、国際原子力機関(IAEA)の援助の基に着手され、「ベータ遅発中性子用データベースの開発」に関するCoordinated Research Project (CRP)が結成された。本論文では、CRPで行われたこれまでの結果について報告をする。
are metabolically diverse compared to gut microbiome and some have a novel nitrogenase paralogM
heust, R.*; Castelle, C. J.*; Matheus Carnevali, P. B.*; Farag, I. F.*; He, C.*; Chen, L.-X.*; 天野 由記; Hug, L. A.*; Banfield, J. F.*
ISME Journal, 14(12), p.2907 - 2922, 2020/12
被引用回数：59 パーセンタイル：96.10(Ecology)We reconstructed 94 draft-quality, non-redundant genomes from diverse animal-associated and natural environments. Genomes group into 12 clades, 10 of which previously lacked reference genomes. Groundwater-associated are predicted to be capable of heterotrophic or autotrophic lifestyles, reliant on oxygen or nitrate/nitrite-dependent respiration of fatty acids, or a variety of organic compounds and Rnf-dependent acetogenesis with hydrogen and carbon dioxide as the substrates. Genomes from two clades of groundwater-associated often encode a new homologous group of nitrogenase-like proteins that co-occur with an extensive suite of radical SAM-based proteins. We identified similar genomic loci in genomes of bacteria from the Gracilibacteria and Myxococcus phyla and predict that the gene clusters reduce a tetrapyrrole, possibly to form a novel cofactor. The animal-associated clades nest phylogenetically within two groundwater-associated clades. Thus, we propose an evolutionary trajectory in which some adapted to animal-associated lifestyles from groundwater-associated species via genome reduction.
