Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Baccou, J.*; Glantz, T.*; Ghione, A.*; Sargentini, L.*; Fillion, P.*; Damblin, G.*; Sueur, R.*; Iooss, B.*; Fang, J.*; Liu, J.*; et al.
Nuclear Engineering and Design, 421, p.113035_1 - 113035_16, 2024/05
被引用回数：0In the Best-Estimate Plus Uncertainty (BEPU) framework, the use of best-estimate code requires to go through a Verification, Validation and Uncertainty Quantification process (VVUQ). The relevance of the experimental data in relation to the physical phenomena of interest in the VVUQ process is crucial. Adequacy analysis of selected experimental databases addresses this problem. The outcomes of the analysis can be used to select a subset of relevant experimental data, to encourage designing new experiments or to drop some experiments from a database because of their substantial lack of adequacy. The development of a specific transparent and reproducible approach to analyze the relevance of experimental data for VVUQ still remains open and is the topic of this contribution. In this paper, the concept of adequacy initially introduced in the OECD/NEA SAPIUM (Systematic APproach for model Input Uncertainty quantification Methodology) activity is formalized. It is defined through two key properties, called representativeness and completeness, that allows considering the multifactorial dimension of the adequacy problem. A new systematic approach is then proposed to analyze the adequacy of a set of experimental databases. It relies on the introduction of two sets of criteria to characterize representativeness and completeness and on the use of multi-criteria decision analysis method to perform the analysis. Finally, the approach is applied in the framework of the new OECD/NEA ATRIUM activity which includes a set of practical IUQ exercises in thermal-hydraulics to test the SAPIUM guideline in determining input uncertainties and forward propagating them on an application case. It allows evaluating the adequacy of eight experimental databases coming from the Super Moby-dick, Sozzi-Sutherland and Marviken experiments and identifying the most adequate ones.
FCC hierarchical martensite transformation under dynamic impact in FeMnAlNiTi alloyLi, C.*; Fang, W.*; Yu, H. Y.*; Peng, T.*; Yao, Z. T.*; Liu, W. G.*; Zhang, X.*; 徐 平光; Yin, F.*
Materials Science & Engineering A, 892, p.146096_1 - 146096_11, 2024/02
被引用回数：0 パーセンタイル：0.02(Nanoscience & Nanotechnology)The quasi-static superelastic responses and hierarchical martensite transformation from body-centered cubic (BCC) to face-centered cubic (FCC) under dynamic impact in Fe
Mn
Al
Ni
Ti
alloys were investigated. Polycrystalline and oligocrystalline alloys were produced through solution heat treatment and cyclic heat treatment processes, respectively. The results show the volume fraction of residual martensite for oligocrystalline alloys is lower, which exhibits better superelastic responses compared with polycrystalline alloys. Dynamic impact tests indicate that, despite the weakening of the grain boundary strengthening effect, the ultimate strength of the oligocrystalline alloys closely matches that of the polycrystalline alloys under dynamic impact. The martensite transformation of the FeMnAlNiTi alloy is characterized as hierarchical under dynamic impact, and increasing strain rates and grain sizes can enhance the BCC FCC martensite transformation, resulting in higher martensite phase fractions for oligocrystalline alloys. The increase in ultimate strength is attributed to the dynamic Hall-Petch effect introduced by more martensite phase interfaces under dynamic impact.
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：2 パーセンタイル：57.37(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.
Hu, Q.*; Wang, Q. M.*; Zhang, T.*; Zhao, C.*; Iltaf, K. H.*; Liu, S. Q.*; 深津 勇太
Energy Reports (Internet), 9, p.3661 - 3682, 2023/12
被引用回数：4 パーセンタイル：73.72(Energy & Fuels)This study evaluates petrophysical properties of representative geological rocks in the context of injectivity, storage space, and caprock integrity for effective utilization and long-term storage of carbon dioxide. A total of 10 geological rocks were selected as representative storage media for consideration as saline aquifers & depleted oil and gas reservoirs, basalts, and cap rocks, as well as utilization in organic-rich shale and coal seams. An integrated suite of laboratory tests, including liquid immersion porosimetry, gas expansion porosimetry, grain size distribution, mercury intrusion porosimetry, and gas diffusion, were performed on these various rock samples. The results exhibit a disparity of petrophysical properties among two broad groups of rocks: rocks selected for possible storage of CO
have porosities of 
10-25%, permeabilities of 10
-10
m
, 
m-sized pore-throat size distribution, and mostly good pore connectivity; in contrast, the potential caprocks have porosities of 0.5-5%, permeabilities of 10
-10
m, pore throat sizes of 
50 nm, and probably poorly connected pore networks. An understanding of the measured facets of pore structure and contribution of fractures is also critical in the context of different testing principles and data interpretation of petrophysical analyses, as well as observational scales in the laboratory and field, and therefore reliable confidence of CO storage and utilization performance. Our work further illustrates the controlling influence of grain size distribution and geological processes on pore size distribution and pore connectivity for a wide range of rock types and lithologies, and particularly presents the extent and behavior of CO gas diffusion with a custom-designed apparatus for a holistic understanding of various petrophysical attributes of widely different geological rocks.
Ca cast doubt on a doubly magic 
CaChen, S.*; Browne, F.*; Doornenbal, P.*; Lee, J.*; Obertelli, A.*; 角田 佑介*; 大塚 孝治*; 茶園 亮樹*; Hagen, G.*; Holt, J. D.*; et al.
Physics Letters B, 843, p.138025_1 - 138025_7, 2023/08
被引用回数：1 パーセンタイル：64.66(Astronomy & Astrophysics)
Scからの1陽子ノックアウト反応を用いて、
Caと
Caのガンマ崩壊を観測した。Caでは1456(12)keVの
線遷移が、Caでは1115(34)keVの遷移が観測された。どちらの遷移も暫定的に
と割り当てられた。有効核子間相互作用をわずかに修正した広い模型空間での殻模型計算では、
準位エネルギー、2中性子分離エネルギー、反応断面積が実験とよく一致し、N=34閉殻の上に新しい殻が形成されていることを裏付けた。その構成要素である
と
軌道はほぼ縮退しており、これはCaが二重魔法核である可能性を排除し、Ca同位体のドリップラインを
Caあるいはそれ以上にまで広げる可能性がある。
Zhang, T.*; Yao, Y.*; 守田 幸路*; Liu, X.*; Liu, W.*; 今泉 悠也; 神山 健司
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 9 Pages, 2023/05
The in-pile EAGLE ID1 test was conducted by Japan Atomic Energy Agency to demonstrate the effectiveness of the fuel assembly with an internal duct structure during a core disruptive accident in a sodium-cooled fast reactor. In this study, a new computational fluid dynamics code based on the fully Lagrangian particle method was developed for the purpose of clarifying the failure mechanism of the inner duct wall of FAIDUS. The three-dimensional simulation of the ID1 test was performed to analyze a series of thermal hydraulic behaviors leading up to duct wall failure for a computational domain that included six fuel pins. The simulations reasonably reproduced the heat transfer characteristics observed in the test, showing that the local contact of liquid steel with high thermal conductivity with the duct wall greatly enhances the heat transfer from the nuclear heating fuel to the duct wall. The results support the validity of the conclusions of our analytical study regarding the molten pool-to-duct wall heat transfer mechanism that caused the thermal failure of the duct wall.
山野 秀将; Chenaud, M.-S.*; Tsige-Tamirat, H.*; Sumner, T.*; Lee, J.*; Liu, S.*; Peregudova, O.*
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 9 Pages, 2023/05
第4世代炉に関する国際フォーラムは、次世代の原子力エネルギーシステムのための研究開発における国際協力を行うための組織である。第4世代ナトリウム冷却高速炉(SFR)の取り決めの中で、SFRの安全と運転(SO)に関するプロジェクトは、安全技術開発と原子炉運転技術開発の分野を取り扱う。SOプロジェクトの目的には、(1)安全アプローチの構築と具体的な安全設備の性能確認を裏付ける解析及び実験、(2)安全評価と施設の認可に使用される計算ツールの開発と検証及びモデルの妥当性確認、(3)運転中のSFRプラントでの経験と試験から広く得られる原子炉運転技術の取得を含む。SOのテーマに含まれるタスクは、以下の3つのワークパッケージ(WP)、すなわち、WP-SO-1「手法,モデル及びコード」、WP-SO-2「実験計画と運転経験」、及びWP-SO-3「革新的な設計と安全システムの研究」に分類される。本論文では、SOプロジェクトにおける最近の活動を報告する。
by monolayer hexagonal boron nitride coating for improved photo- and thermionic-cathodes山口 尚登*; 遊佐 龍之介*; Wang, G.*; Pettes, M. T.*; Liu, F.*; 津田 泰孝; 吉越 章隆; 虻川 匡司*; Moody, N. A.*; 小川 修一*
Applied Physics Letters, 122(14), p.141901_1 - 141901_7, 2023/04
被引用回数：3 パーセンタイル：81.68(Physics, Applied)単層BMをコートしたLaBの仕事関数の低減に関して報告する。hBNでコートされた領域は、非被覆あるいはグラフェンコートされたLaB(100)単結晶領域に比べて仕事関数が低下していることが、光電子顕微鏡(PEEM)および熱電子顕微鏡(TEEM)実験から分かった。グラフェンコートに比べてhBNコートされたLaB(100)では、非常に大きな仕事関数の低下が起きることが、DFT計算から定性的に分かった。計算に酸化層を考慮すると、計算と実験の間の整合性が改善された。放射光XPSによって、我々のLaB表面に酸化層が実在することを確認した。
100 MeV/nucleonPohl, T.*; Sun, Y. L.*; Obertelli, A.*; Lee, J.*; G
mez-Ramos, M.*; 緒方 一介*; 吉田 数貴; Cai, B. S.*; Yuan, C. X.*; Brown, B. A.*; et al.
Physical Review Letters, 130(17), p.172501_1 - 172501_8, 2023/04
被引用回数：5 パーセンタイル：93.15(Physics, Multidisciplinary)大きなフェルミ面非対称性を持つ陽子過剰な
O原子核からの100MeV/nucleonでの陽子による陽子・中性子除去反応について報告した。この結果は、quasi-freeノックアウト反応、非弾性散乱、核子移行反応を含む複数の反応機構の定量的寄与を初めて示すものである。このようなエネルギー領域では通常無視される非弾性散乱と核子移行の寄与が、弱束縛陽子と強束縛中性子の除去反応断面積にそれぞれ約50%と30%寄与していることが示された。
間所 寛; 山下 拓哉; Gaus-Liu, X.*; Cron, T.*; Fluhrer, B.*; 佐藤 一憲; 溝上 伸也*
Nuclear Technology, 209(2), p.144 - 168, 2023/02
被引用回数：0 パーセンタイル：0.01(Nuclear Science & Technology)Since the reactor pressure vessel (RPV) lower head failure determines the subsequent ex-vessel accident progression, it is a key issue to understand the accident progression of Fukushima Daiichi Nuclear Power Station (1F). The RPV failure is largely affected by thermal loads on the vessel wall and thus it is inevitable to understand thermal behavior of molten metallic pool with co- existence of solid oxide fuel debris. In the past decades, numerous experiments have been conducted to investigate a homogeneous molten pool behavior. Few experiments, however, addresses the melting and heat transfer process of debris bed consisted of materials with different melting temperatures. LIVE-J2 experiment aimed to provide the experimental data on a solid-liquid mixture pool in a simulated RPV lower head under various conditions. The extensive measurements of the melt temperature indicate the heat transfer regimes in a solid-liquid mixture pool. The test results showed that the conductive heat transfer was dominant during the steady state along the vessel wall boundary and that convective heat transfer takes place inside the mixture pool. Besides the experimental performance, the test case was numerically simulated by using ANSYS Fluent. The simulation results generally agree with the measured experimental data. The flow regime and transient melt evolution were able to be estimated by the calculated velocity field and the crust thickness, respectively.
Chen, J.*; 山本 慧; Zhang, J.*; Ma, J.*; Wang, H.*; Sun, Y.*; Chen, M.*; Ma, J.*; Liu, S.*; Gao, P.*; et al.
Physical Review Applied (Internet), 19(2), p.024046_1 - 024046_9, 2023/02
被引用回数：6 パーセンタイル：87.72(Physics, Applied)Coherent coupling in magnon based hybrid system has many potential applications in quantum information processing. Magnons can propagate in magnetically ordered materials without any motion of electrons, offering a unique method to build low-power-consumption devices and information channels free of heat dissipation. In this article, we demonstrate the coherent propagation of hybridized modes between spin waves and Love surface acoustic waves in a multiferroic BiFeO
and ferromagnetic La
Sr
MnO based heterostructure. The magneto-elastic coupling enables a giant enhancement of strength of the hybridized mode by a factor of 26 compared to that of the pure spin waves. A short wavelength down to 250 nm is demonstrated for the hybridized mode, which is desirable for nanoscale acousto-magnonic applications. Our combined experimental and theoretical analyses represent an important step towards the coherent control in hybrid magnonics, which may inspire the study of magnon-phonon hybrid systems for coherent information processing and manipulation.
Zhang, T.*; 守田 幸路*; Liu, X.*; Liu, W.*; 神山 健司
Annals of Nuclear Energy, 179, p.109389_1 - 109389_10, 2022/12
被引用回数：1 パーセンタイル：29.26(Nuclear Science & Technology)The ID1 test was the final target test of the EAGLE experimental framework program. It was used to verify that during a core disruptive accident, the molten fuel could be discharged via wall failure of an inner duct in FAIDUS, a design concept for the sodium-cooled fast reactor. The ID1 results revealed that the wall failure behavior owed to the large heat flow from the surrounding fuel/steel mixture. The present study numerically investigated the heat transfer mechanisms in the test using the finite volume particle method in the three-dimensional domain. The thermal hydraulic behaviors during wall failure were reproduced reasonably. The present three-dimensional simulation mitigated inherent defects of our previous two-dimensional calculation and clarified that the solid fuel and liquid steel close to the outer surface of the duct can expose the duct to high thermal loads, resulting in the wall failure.
Liu, X. J.*; 徐 平光; 城 鮎美*; Zhang, S. Y.*; 菖蒲 敬久; 行武 栄太郎*; 秋田 貢一*; Zolotoyabko, E.*; Liss, K.-D.*
Journal of Materials Science, 57(46), p.21446 - 21459, 2022/12
被引用回数：3 パーセンタイル：38.91(Materials Science, Multidisciplinary)In situ time/temperature-resolved synchrotron high-energy X-ray diffraction is applied to study heat-mediated structural changes and phase transformations in rolled sheets of AZ91 and AZ31 magnesium alloys. Azimuthal diffraction intensities along the Debye-Scherrer rings (AT-plots) are used to obtain information on grain recovery and recrystallization temperatures as well as temperature-assisted grain rotations. The azimuthally integrated diffraction intensities, plotted as functions of the scattering vector (QT-plots), provide vital data on the temperature-dependent lattice parameters of the Mg/Al matrix and intermetallic precipitates, as well as on the evolution of the precipitates' volume fraction. It was found that in AZ31, the main precipitates are of the AlMn type, which is rather stable in the investigated temperature range (up to 773 K). In contrast, in AZ91, the major intermetallic precipitates, Al
Mg
, undergo complete dissolution above 600 K. It is caused by the enhanced diffusion of Al into the Mg/Al matrix, which according to the Al-Mg phase diagram, can adopt more Al at elevated temperatures. This diffusion is revealed by the proportional diminishing of the matrix lattice parameter (chemical strain), allowing us to quantify the Al content in the matrix. Fast temperature-dependent manipulation with intermetallic content in the Mg/Al alloy can, in principle, be used for controlling its mechanical properties.
island of inversion; First study of low-lying bound excited states in 
V and 
VElekes, Z.*; Juh
sz, M. M.*; Sohler, D.*; Sieja, K.*; 吉田 数貴; 緒方 一介*; Doornenbal, P.*; Obertelli, A.*; Achouri, N. L.*; 馬場 秀忠*; et al.
Physical Review C, 106(6), p.064321_1 - 064321_10, 2022/12
被引用回数：2 パーセンタイル：49.92(Physics, Nuclear)VとVの低励起準位構造を初めて探索した。Vについては中性子ノックアウト反応と陽子非弾性散乱が、Vについては中性子ノックアウト反応データが得られた。Vについては4つ、Vについては5つの新たな遷移が確認された。Lenzi-Nowacki-Poves-Sieja (LNPS)相互作用に基づく殻模型計算との比較によって、それぞれの同位体について確認されたガンマ線のうち3つが、first 11/2
状態とfirst 9/2状態からの崩壊と決定された。Vについては、(
,
)非弾性散乱断面積は四重極変形と十六重極変形を想定したチャネル結合法により解析されたが、十六重極変形の影響により、明確に反転の島に属するとは決定できなかった。
neutron orbital and the 
shell closure in 
CaEnciu, M.*; Liu, H. N.*; Obertelli, A.*; Doornenbal, P.*; Nowacki, F.*; 緒方 一介*; Poves, A.*; 吉田 数貴; Achouri, N. L.*; 馬場 秀忠*; et al.
Physical Review Letters, 129(26), p.262501_1 - 262501_7, 2022/12
被引用回数：5 パーセンタイル：65.23(Physics, Multidisciplinary)230MeV/nucleonでのCaからの中性子ノックアウト反応が線分光と行われ、
と
軌道からの中性子ノックアウト反応の運動量分布が測定された。断面積は
の閉殻と整合し、Ca同位体での
と
閉殻と同程度に強い閉殻であることが確認された。運動量分布の分析から
と軌道の平均二乗根半径の差は0.61(23)fmと決定され、これはmodified-shell-modelによる予言の0.7fmと整合した。これは、中性子過剰なCa同位体での軌道半径が大きいことが、中性子数にしたがって線形的に荷電半径が増える意外な現象の原因であることを示唆している。
Zhang, J.*; Kuang, L.*; Mou, Z.*; 近藤 俊明*; 小嵐 淳; 安藤 麻里子; Li, Y.*; Tang, X.*; Wang, Y.-P.*; Pe
uelas, J.*; et al.
Plant and Soil, 481(1-2), p.349 - 365, 2022/12
被引用回数：4 パーセンタイル：52.15(Agronomy)Soil warming effects on soil organic carbon (SOC) decomposition and stabilization are highly variable, and the underlying mechanisms are poorly understood. In this study, concentration, stability (dissolved, particle and mineral-associated SOC), and source (plant-derived and microbial-derived) of SOC, soil microbial community composition, and enzyme activities were studied in a 10-year soil warming field experiment in an East Asian monsoon forest. The results showed that 10-year soil warming significantly enhanced SOC in the top 0-10 cm soil. The increased SOC induced by warming was mainly derived from plants with lignin markers, accompanied by a decrease in microbial-derived SOC. This highlights an urgent need for a better understanding of how the contrasting effects of plant- and microbial-derived C mediate the response of the SOC pool to warming across different biomes.
BaCo(PO
)Sheng, J.*; Wang, L.*; Candini, A.*; Jiang, W.*; Huang, L.*; Xi, B.*; Zhao, J.*; Ge, H.*; Zhao, N.*; Fu, Y.*; et al.
Proceedings of the National Academy of Sciences of the United States of America, 119(51), p.e2211193119_1 - e2211193119_9, 2022/12
被引用回数：4 パーセンタイル：56.47(Multidisciplinary Sciences)Although considerable progress has been made in the theoretical understanding of the low-dimensional frustrated quantum magnets, experimental realizations of a well-established scaling analysis are still scarce. This is particularly true for the two-dimensional antiferromagnetic triangular lattices. Owing to the small exchange strength, the newly discovered compound NaBaCo(PO) provides a rare opportunity for clarifying the quantum criticality in an ideal triangular lattice with quantum spin S=1/2. In addition to the establishment of the complete phase diagrams, the spin Hamiltonian with a negligible interplane interaction has been determined through the spin wave dispersion in the polarized state, which is consistent with the observation of a two-dimensional quantum critical point with the Bose-Einstein condensation of diluted free bosons.
La
Fe
Ni
AsXie, 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(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.
高塚 大地*; 守田 幸路*; Liu, W.*; Zhang, T.*; 中村 武志*; 神山 健司
Proceedings of 12th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS12) (Internet), 10 Pages, 2022/10
A 3D particle-based simulation code was developed to analyze jet impingement behavior, and the physical models for thermal-hydraulic interactions between molten jets and solid plates used in the code was validated by simulating existing jet impingement experiments. In addition, particle-based simulations were conducted to understand the impingement characteristics of molten MOX fuel jets on SS plates, and the erosion rate of the SS plate was evaluated. The results showed that fuel crusts formed on the plate potentially provide thermal protection and confirmed the effect of the plate erosion rate on the jet diameter under conditions where crust formation is dominant.
beam at the SNSGorlov, T.*; Aleksandrov, A.*; Cousineau, S.*; Liu, Y.*; Oguz, A. R.*; Kay, M.*; Saha, P. K.
Proceedings of the 2022 North American Particle Accelerator Conference (NAPAC 2022) (Internet), p.702 - 704, 2022/08
The conventional method of H charge-exchange injection by using a solid stripper foil has serious drawbacks such as, a short foil lifetime, unexpected failure and moreover a high residual radiation due to uncontrolled foil scattering beam losses at high-intensity operation. To overcome all those issues, an H stripping by using only lasers or by laser assisted are being extensively studied at J-PARC and the Spallation Neutron Source (SNS) at Oak Ridge, USA, respectively. However, a reduction of the laser power to realize the laser stripping is a common issue at both labs. In this research, different schemes and methods of laser stripping, especially for an effective excitation of the ground state hydrogen atom are considered. Among all methods the most realistic and practical scheme seems to be the sequential excitation scheme by using two types of laser. In this case, a laser power can be reduced to 1/25 as compared to a single step excitation. Due to a lower H energy, a deep UV laser is used at J-PARC. Such a reduction of the laser power is further useful for a realistic implementation.
