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論文

Gradient residual strain measurement procedure in surface impacted railway steel axles by using neutron scattering

Zhou, L.*; Zhang, H.*; Qin, T. Y.*; Hu, F. F.*; 徐 平光; Ao, N.*; Su, Y. H.; He, L. H.*; Li, X. H.*; Zhang, J. R.*; et al.

Metallurgical and Materials Transactions A, 11 Pages, 2024/00

High-speed railway S38C axles undergo surface induction hardening for durability, but are susceptible to fatigue cracks from foreign object impact. The neutron diffraction method was employed to measure the residual strain in S38C axles, obtaining microscopic lattice distortion data, for the gradient layer at a depth of 8 mm under the surface. The results showed that after induction-hardening, the microscopic lattice distortion had a gradient distribution, decreasing with the distance from the surface. However, in the case of impacting speed of 600 km/m, the average microscopic lattice distortion increased with the distance from the surface, reaching a maximum augmentation of 55 pct. These findings indicate a strong experimental basis, and improve our understanding of the relationship between macroscopic residual stress and decision-making, in regard to operation and maintenance.

論文

Cryogenic impact fracture behavior of a high-Mn austenitic steel using electron backscatter diffraction and neutron Bragg-edge transmission imaging

Wang, Y. W.*; Wang, H. H.*; Su, Y. H.; 徐 平光; 篠原 武尚

Materials Science & Engineering A, 887, p.145768_1 - 145768_13, 2023/11

A unique impact fracture behavior is found in a high-Mn austenitic steel (24Mn-4Cr-0.4C-0.3Cu) in this work. The steel exhibits concurrent twinning-induced plasticity (TWIP) effect and the transformation-induced plasticity (TRIP) effect. By analyzing the load-deflection curves recorded during Charpy impact testing, the resistance to crack initiation and propagation is quantified from the absorbed energy. The high-Mn steel demonstrates good resistance to crack initiation at 273 K and 77 K. However, as the temperature decreases from 273 K to 77 K, there is an accelerated transition from stable crack growth to unstable crack growth during impact, resulting in the deterioration of resistance to crack propagation. The plastic deformation of the impact-tested samples, especially in the region close to the crack-path profile was quantitatively analyzed using neutron Bragg-edge transmission (BET) imaging. The deformation zones, divided by using the width of the 200 Bragg edge, exhibit good agreement with the impact absorbed energy characteristics obtained from dynamic load-deflection curves. Moreover, the unstable growth transition point was roughly determined on the impact-tested sample. Then, the electron backscatter diffraction (EBSD) technique is employed to examine the deformation microstructure along the crack-path in the impact-tested samples. The results revealed the dual roles of TRIP effect in impact toughness of the high-Mn steel. On one hand, the TRIP effect plays a positive role in improving resistance to crack initiation and propagation. On the other hand, the excessive accumulation of brittle $$varepsilon$$/$$alpha$$'-martensite caused by the enhanced TRIP effect at 77 K leads to quasi-cleavage fracture, thereby playing a negative role. Finally, we discussed the prominent toughening mechanisms associated with the TWIP and TRIP effects, which greatly impact the impact fracture behavior.

論文

Update of Bragg edge analysis software "GUI-RITS"

及川 健一; 佐藤 博隆*; 渡辺 賢一*; Su, Y. H.; 篠原 武尚; 甲斐 哲也; 鬼柳 善明*; 長谷美 宏幸

Journal of Physics; Conference Series, 2605, p.012013_1 - 012013_6, 2023/10

Spectral data of Bragg-edge imaging, which is one of the energy-resolved neutron imaging methods, can be analyzed by single-edge analysis and full-pattern analysis with the Bragg-edge analysis code RITS developed by Sato et al. This program has a function to generate neutron transmission data considering wavelength-dependent pulse-shape function, atomic number density, crystalline structure, etc., and to extract these parameters from the measured data by the nonlinear least-squares fitting. Last year, we worked on updating the operating environment of the platform Scientific Linux 6 and the language Python 2, which have been discontinued, to Windows 10 and Python 3, and added some functions to improve usability. GUI-RITS for the windows platform has been released to users. In this presentation, we will show concrete examples of the results of the analysis of the same data by the old and new programs, and compare the efficiency of data analysis.

論文

Residual stress relaxation by bending fatigue in induction-hardened gear studied by neutron Bragg edge transmission imaging and X-ray diffraction

Su, Y. H.; 及川 健一; 篠原 武尚; 甲斐 哲也; 堀野 孝*; 井戸原 修*; 三阪 佳孝*; 友田 陽*

International Journal of Fatigue, 174, p.107729_1 - 107729_12, 2023/09

 被引用回数:1 パーセンタイル:63.29(Engineering, Mechanical)

A novel procedure, double induction quenching (DIQ), effective for improving the fatigue strength of gear products, has been used for producing gears with steep gradients of compressive residual stress generated in the tooth surface. We performed a Bragg edge imaging experiment at a pulsed neutron source to determine the spatial distribution of the {110} lattice spacing (d$$_{110}$$) and the broadening of the {110} Bragg edge (w$$_{110}$$) on the DIQ gear product after tooth-bending fatigue tests to which different loading cycles were applied. No significant difference occurred in the d$$_{110}$$ and the w$$_{110}$$at Hofer 's critical section of the teeth with different loading conditions within the accuracy of data analysis. However, we detected a decrease in the w$$_{110}$$ and changes in the residual lattice strain distribution in the axial direction along the tooth root directions at the opposite side of Hofer 's critical section for both teeth after 3$$times$$10 $$^{5}$$ and 8$$times$$10 $$^{5}$$ cycles, relieving the compressive residual stresses during the fatigue process. The residual stress close to the gear tooth surface determined by X-ray diffraction using sequential polishing showed a slight relaxation and redistribution from the tensile side in the hoop direction, complementary to the neutron Bragg edge imaging.

論文

Corrosion fatigue crack growth behavior of a structurally gradient steel for high-speed railway axles

Ao, N.*; Zhang, H.*; Xu, H. H.*; Wu, S. C.*; Liu, D.*; 徐 平光; Su, Y. H.; Kang, Q. H.*; Kang, G. Z.*

Engineering Fracture Mechanics, 281, p.109166_1 - 109166_14, 2023/03

 被引用回数:0 パーセンタイル:87.7(Mechanics)

Considering the complex service environments that high-speed railway axles are subjected to, the fatigue crack growth (FCG) behavior of a structurally gradient axle steel with different pre-crack depths both in air and corrosive medium was investigated at a frequency of 5 Hz. The results indicated that in the high $$Delta$$$$K$$ region, FCG rate was dramatically accelerated by corrosion, but the gap narrows as $$Delta$$$$K$$ decreased. The accelerated corrosion FCG rate was a comprehensive result of the acceleration effect of the anodic dissolution, hydrogen-enhanced localized plasticity and the retardation effect of corrosion-induced crack-tip blunting. Despite the fact that the corrosion resistance gradually decreased as the pre-crack depth increased, the FCG rate in the corrosive medium gradually decreased. This was because fatigue loading played a more important role than corrosion in accelerating the corrosion FCG rate.

論文

Fatigue crack non-propagation behavior of a gradient steel structure from induction hardened railway axles

Zhang, H.*; Wu, S. C.*; Ao, N.*; Zhang, J. W.*; Li, H.*; Zhou, L.*; 徐 平光; Su, Y. H.

International Journal of Fatigue, 166, p.107296_1 - 107296_11, 2023/01

 被引用回数:0 パーセンタイル:40.44(Engineering, Mechanical)

Abnormal damages in railway axles can lead to a significant hazard to running safety and reliability. To this end, a surface treatment was selected to effectively inhibit fatigue crack initiation and growth. In this study, a single edge notch bending fatigue test campaign with artificial notches was conducted to elucidate the fatigue crack non-propagation behavior in railway S38C axles subjected to an induction hardening process. The fatigue cracking behavior in the gradient structure was revealed by optical microscopy, electron backscatter diffraction, and fractography. The microhardness distribution was measured using a Vickers tester. The obtained results show that the microhardness of the strengthening layer is nearly triple that of the matrix. Owing to the gradient microstructures and hardness, as well as compressive residual stress, the fatigue long crack propagates faster once it passes through the hardened zone (approximately 2.0 mm in the radial depth). Thereafter, local retarding (including deflection, branching, and blunting) of the long crack occurs because of the relatively coarse ferrite and pearlite in the transition region and matrix. Totally, this fatigue cracking resistance is reasonably believed to be due to the gradient microstructure and residual stress. These findings help to tailor a suitable detection strategy for maximum defects or cracks in railway axles.

論文

Strain distribution visualization of punched electrical steel sheets using neutron Bragg-edge transmission imaging

笹田 星児*; Takahashi, Yoshihito*; Takeuchi, Keisuke*; 廣井 孝介; Su, Y. H.; 篠原 武尚; 渡辺 賢一*; 瓜谷 章*

Japanese Journal of Applied Physics, 61(4), p.046004_1 - 046004_8, 2022/03

Residual strains in a punched electrical steel sheet increase the iron loss in the steel sheet. To accurately estimate the effect of residual strain on iron loss, the residual strain distribution in a punched electrical steel sheet should be evaluated. In this study, we demonstrated the two- dimensional imaging of the residual strain distribution in a punched electrical steel sheet using the neutron Bragg-edge transmission imaging method. To improve the accuracy of strain measurement with minimal deterioration of spatial resolution, we applied a process of superposing many specimen images. The tensile strain near the punched edge and the compressive strain inside the core were experimentally confirmed using this method. Finally, the neutron Bragg-edge imaging results and those obtained from kernel average misorientation map using electron backscattered diffraction were compared to verify the validity of the proposed method.

論文

The $$^{59}$$Fe(n,$$gamma$$)$$^{60}$$Fe cross section from the surrogate ratio method and its effect on the $$^{60}$$Fe nucleosynthesis

Yan, S. Q.*; Li, X. Y.*; 西尾 勝久; Lugaro, M.*; Li, Z. H.*; 牧井 宏之; Pignatari, M.*; Wang, Y. B.*; Orlandi, R.; 廣瀬 健太郎; et al.

Astrophysical Journal, 919(2), p.84_1 - 84_7, 2021/10

 被引用回数:1 パーセンタイル:9.31(Astronomy & Astrophysics)

The long-lived $$^{60}$$Fe (with a half-life of 2.62 Myr) is a crucial diagnostic of active nucleosynthesis in the Milky Way galaxy and in supernovae near the solar system. The neutron-capture reaction $$^{59}$$Fe(n,$$gamma$$)$$^{60}$$Fe on $$^{59}$$Fe (half-life=44.5 days) is the key reaction for the production of $$^{60}$$Fe in massive stars. This reaction cross section has been previously constrained by the Coulomb dissociation experiment, which offered partial constraint on the E1 $$gamma$$-ray strength function but a negligible constraint on the M1 and E2 components. In this work, for the first time, we use the surrogate ratio method to experimentally determine the $$^{59}$$Fe(n,$$gamma$$)$$^{60}$$Fe cross sections in which all the components are included. We derived a Maxwellian-averaged cross section of 27.5$$pm$$3.5 mb at $$kT$$ = 30 keV and 13.4$$pm$$1.7 mb at $$kT$$ = 90 keV, roughly 10%-20% higher than previous estimates. We analyzed the impact of our new reaction rates in nucleosynthesis models of massive stars and found that uncertainties in the production of $$^{60}$$Fe from the $$^{59}$$Fe(n,$$gamma$$)$$^{60}$$Fe rate are at most 25$$%$$. We conclude that stellar physics uncertainties now play a major role in the accurate evaluation of the stellar production of $$^{60}$$Fe.

論文

Neutron Bragg-edge transmission imaging for microstructure and residual strain in induction hardened gears

Su, Y. H.; 及川 健一; 篠原 武尚; 甲斐 哲也; 堀野 孝*; 井戸原 修*; 三阪 佳孝*; 友田 陽*

Scientific Reports (Internet), 11, p.4155_1 - 4155_14, 2021/02

 被引用回数:11 パーセンタイル:71.97(Multidisciplinary Sciences)

A time-of-flight Bragg-edge neutron transmission imaging was used to investigate the microstructure and strain distributions in a gear hardened by a newly developed two-step induction-heating method: precursor (Sample 1) and final product (Sample 2). The edge- position and edge-broadening were determined and mapped with high spatial resolution, which enabled us to confirm the two-dimensional distributions of the microstructure and residual strain. A deep hardened layer was made for Sample 1 in which martensite was formed on the entire teeth and the outer peripheral portion of the gear body. Sample 2 was subjected to double induction-hardening, where a tempered martensite was formed as the thermal refined microstructure between a fine-grained martensite at the tooth surface and a ferrite-pearlite microstructure at the core. The relationship between edge-broadening and the Vickers hardness described by a linear equation was employed to derive the elastic residual strain. The residual strain map for Sample 2 revealed that a steep compressive strain was introduced into the fine-grained martensite at the tooth surface by the super rapid induction- heating and quenching process. The reversal of tension was speculated to occur below 2 mm from the tooth tip, and the strain was almost zero in the core region.

論文

Influence of carbon concentration and magnetic transition on the austenite lattice parameter of 30Mn-C steel

友田 陽*; 村上 俊夫*; Wang, Y. X.*; 大村 孝仁*; Harjo, S.; Su, Y. H.; 篠原 武尚

Materials Characterization, 163, p.110243_1 - 110243_8, 2020/05

 被引用回数:3 パーセンタイル:33.57(Materials Science, Multidisciplinary)

In this study, the effects of carbon concentration and magnetic transition on the austenite lattice parameter of Fe-30Mn-$$x$$C alloys were assessed. A linear relationship was obtained between the carbon content and the lattice parameter determined by neutron diffraction and neutron Bragg-edge transmission imaging for austenitic steels bearing 0.007-1.20 mass% C. The results obtained through both methods showed good agreement. In addition, carbon partitioning was evaluated in artificially piled-up discs with different carbon contents in order to develop a new technique for advanced multi-phase steels. The analysis of asymmetry and broadening of the diffraction line profile revealed that the carbon partitioning could be determined. In conclusion, the results presented herein expand the current knowledge on the properties of high Mn austenite.

論文

Development of event-type neutron imaging detectors at the energy-resolved neutron imaging system RADEN at J-PARC

Parker, J. D.*; 原田 正英; 林田 洋寿*; 廣井 孝介; 甲斐 哲也; 松本 吉弘*; 中谷 健; 及川 健一; 瀬川 麻里子; 篠原 武尚; et al.

Materials Research Proceedings, Vol.15, p.102 - 107, 2020/05

At the RADEN instrument, we take advantage of the accurate measurement of neutron energy by time-of-flight to perform energy-resolved neutron imaging using event-type neutron imaging detectors. We are continually working to improve these detectors for better spatial resolution and shorter measurement times and, as a user facility, to improve the ease-of-use of their control and analysis software. In particular, we are actively developing a $$^{3}$$He-based gaseous micropattern detector known as the Micro-pixel chamber based Neutron Imaging Detector ($$mu$$ NID). We have recently redesigned the $$mu$$ NID control software to allow full integration into the automated experiment control system at RADEN, and we are carrying out optimization of the analysis algorithms for improved image quality and rate performance.

論文

The Energy-resolved neutron imaging system, RADEN

篠原 武尚; 甲斐 哲也; 及川 健一; 中谷 健; 瀬川 麻里子; 廣井 孝介; Su, Y. H.; 大井 元貴; 原田 正英; 飯倉 寛; et al.

Review of Scientific Instruments, 91(4), p.043302_1 - 043302_20, 2020/04

 被引用回数:42 パーセンタイル:96.38(Instruments & Instrumentation)

The energy-resolved neutron imaging system, RADEN, has been installed at the pulsed neutron source in the Materials and Life Science Experimental Facility of the Japan Proton Accelerator Research Complex. In addition to conventional neutron radiography and tomography, RADEN, the world's first imaging beam-line at a pulsed neutron source, provides three main options for new, quantitative neutron imaging techniques: Bragg-edge imaging to visualize the spatial distribution of crystallographic information, resonance absorption imaging for elemental composition and temperature information, and polarized neutron imaging for magnetic field information. This paper describes the results of characterization studies of the neutronic performance and installed devices at RADEN and shows the results of several demonstration studies for pulsed neutron imaging.

論文

Feasibility study of two-dimensional neutron-resonance thermometry using molybdenum in 316 stainless-steel

甲斐 哲也; 廣井 孝介; Su, Y. H.; 瀬川 麻里子; 篠原 武尚; 松本 吉弘*; Parker, J. D.*; 林田 洋寿*; 及川 健一

Materials Research Proceedings, Vol.15, p.149 - 153, 2020/02

A two-dimensional thermometry technique based on neutron resonance reactions derives the temperature of specified elements in an object by analyzing the Doppler broadening of a neutron resonance measured by a time-analyzing neutron imaging-detector. This technique is expected to be one of the important applications of the energy-resolved neutron imaging system, RADEN, at J-PARC. The authors focused on molybdenum contained in 316 stainless-steel (with a weight fraction of 2-3 wt%). Energy-dependent transmitted neutrons were measured through a 3 mm thick 316 stainless-steel plate placed in a heater at temperatures between 23 and 500 degrees Celsius at RADEN using a gas-electron multiplier (GEM) detector. Thermal and cold neutrons were eliminated from the incident beam by a cadmium filter. The sample area within the neutron beam was 30 by 50 mm$$^2$$. The feasibility is discussed in the presentation.

論文

Comparison of heavy-ion transport simulations; Collision integral with pions and $$Delta$$ resonances in a box

小野 章*; Xu, J.*; Colonna, M.*; Danielewicz, P.*; Ko, C. M.*; Tsang, M. B.*; Wang, Y,-J.*; Wolter, H.*; Zhang, Y.-X.*; Chen, L.-W.*; et al.

Physical Review C, 100(4), p.044617_1 - 044617_35, 2019/10

AA2019-0025.pdf:2.76MB

 被引用回数:52 パーセンタイル:98.56(Physics, Nuclear)

2017年4月に開催された国際会議Transport2017において、重イオン核反応モデルの国際的な比較が議論された。重イオン加速器の安全評価や宇宙飛行士の被ばく評価等で重要な役割を果たすため、世界中で重イオン核反応の様々な理論モデルが開発されている。本研究では、辺の長さが20fmの直方体に320個の中性子と陽子をランダム配置し、それらが70fm/cの間に起こす散乱の回数やエネルギーを計算した。ここでは、特にパイオンやその前駆体であるデルタ共鳴の生成に注目して比較を行った。参加コードは、個々の粒子の時間発展を追うQMD型コードと、粒子の位置や運動量の確率分布を決めておき、散乱や崩壊が発生したときそれらを乱数サンプリングするBUU型コードがあり、発表者が用いたJQMDは前者に属する。本研究により、計算における時間刻みが各コードによる結果の差の主な原因であることが分かった。さらに、今後のJQMDの改良方針の策定に有益な知見を得ることができた。

論文

水素分配制御によるアルミニウム合金の力学特性最適化

戸田 裕之*; 山口 正剛; 松田 健二*; 清水 一行*; 平山 恭介*; Su, H.*; 藤原 比呂*; 海老原 健一; 板倉 充洋; 都留 智仁; et al.

鉄と鋼, 105(2), p.240 - 253, 2019/02

 被引用回数:0 パーセンタイル:0(Metallurgy & Metallurgical Engineering)

本レビューでは、高強度アルミニウム合金の水素脆化に関する研究活動、特に様々なトラップサイトでの水素トラップとそれによる水素脆化への影響に焦点を当てて報告する。高亜鉛濃度Al-Zn-Mg合金において、高分解能TEM法による析出物のナノ構造及び界面構造の分析や、高分解能X線マイクロトモグラフィー技術による詳細な破壊マイクロメカニズムとマイクロ構造-破壊特性関係の調査がなされ、さらに、ごく最近実現された超高分解能X線顕微鏡により特徴的な局部的変形、亀裂の発生・成長が観察されている。また、第一原理シミュレーションによる数々の水素トラップサイトのトラップエネルギー導出を元に、変形・破壊中の水素再分配が解析された。水素の再分配と3つの異なるミクロ機構による水素脆化との間の関係を論じ、水素脆化が起こるための現実的な条件を説明する。

論文

Battery-free, skin-interfaced microfluidic/electronic systems for simultaneous electrochemical, colorimetric, and volumetric analysis of sweat

Bandodkar, A. J.*; Gutruf, P.*; Choi, J.*; Lee, K.-H.*; 関根 由莉奈; Reeder, J. T.*; Jeang, W. J.*; Aranyosi, A. J.*; Lee, S. P.*; Model, J. B.*; et al.

Science Advances (Internet), 5(1), p.eaav3294_1 - eaav3294_15, 2019/01

 被引用回数:386 パーセンタイル:99.88(Multidisciplinary Sciences)

非侵襲でバイオマーカーを検出し得るウェアラブルデバイスが注目されている。しかしながら現在までに存在するウェアラブルデバイスはその電力源や検出部分などの小型化が困難であったことから重さや大きさの点でポータビリティに欠けていた。本研究では、バッテリーフリーでかつ電気的、呈色式を用いて重要バイオマーカーである塩化物, 乳酸, グルコース, pHを検出できるスウェットデバイスを開発した。

論文

Comparison of heavy-ion transport simulations; Collision integral in a box

Zhang, Y.-X.*; Wang, Y,-J.*; Colonna, M.*; Danielewicz, P.*; 小野 章*; Tsang, M. B.*; Wolter, H.*; Xu, J.*; Chen, L.-W.*; Cozma, D.*; et al.

Physical Review C, 97(3), p.034625_1 - 034625_20, 2018/03

 被引用回数:90 パーセンタイル:99.11(Physics, Nuclear)

2017年4月に開催された国際会議Transport2017において、重イオン核反応モデルの国際的な比較が議論された。重イオン加速器の安全評価や宇宙飛行士の被ばく評価等で重要な役割を果たすため、世界中で重イオン核反応の様々な理論モデルが開発されている。本研究はモデル間の共通点と差異を明らかにし、各モデルの問題点を明らかにした。比較において、辺の長さが20fmの直方体に320個の中性子と320個の陽子をランダム配置し、それらが時間発展に伴って起こす散乱の回数や散乱時のエネルギーなどを計算する条件が設定された。また、結果以外にも、理論モデルを構成するアルゴリズムについても比較を行った。発表者は重イオン核反応モデルJQMD(JAERI Quantum Molecular Dynamics)を用いて計算を行い、世界で開発されている15の計算コードによる計算結果と比較した。コードアルゴリズムの比較では、JQMDは必ず陽子から 優先的に衝突確率を計算し、その後に中性子の衝突を計算するため、物理描像の妥当性が指摘された。一方、JQMDは他のモデルとほぼ同じ計算結果を出すことも判明した。衝突回数や運動量の計算値が平均から2倍以上乖離するモデルもある中で、JQMDは本計算条件で安定した性能を発揮することが確認された。

論文

The $$^{95}$$Zr($$n, gamma$$)$$^{96}$$Zr cross section from the surrogate ratio method and its effect on $$s$$-process nucleosynthesis

Yan, S. Q.*; Li, Z. H.*; Wang, Y. B.*; 西尾 勝久; Lugaro, M.*; Karakas, A. I.*; 牧井 宏之; Mohr, P.*; Su, J.*; Li, Y. J.*; et al.

Astrophysical Journal, 848(2), p.98_1 - 98_8, 2017/10

 被引用回数:5 パーセンタイル:21.72(Astronomy & Astrophysics)

The $$^{95}$$Zr($$n, gamma$$)$$^{96}$$Zr reaction cross section is crucial in the modelling of $$s$$-process nucleosynthesis in asymptotic giant branch stars because it controls the operation of the branching point at the unstable $$^{95}$$Zr and the subsequent production of $$^{96}$$Zr. We have carried out the measurement of the $$^{90}$$Zr($$^{18}$$O,$$^{16}$$O) and $$^{94}$$Zr($$^{18}$$O,$$^{16}$$O) reactions and obtained the $$gamma$$-decay probability ratio of $$^{92}$$Zr$$^{*}$$ and $$^{96}$$Zr$$^{*}$$ to determine the $$^{95}$$Zr($$n, gamma$$)$$^{96}$$Zr reaction cross sections with the surrogate ratio method. We tested our deduced maxwellian-averaged cross section in stellar models with masses between 2 and 6 $$M_{odot}$$ and metallicities 0.014 and 0.03. The largest changes - up 80 % variations in $$^{96}$$Zr - are seen in the models of 3-4 $$M_{odot}$$, where the $$^{22}$$Ne neutron source is mildly activated. The new rate can still provide a match to data from meteoritic stardust silicon carbide grains, provided the maximum mass of the parent stars is below 4 $$M_{odot}$$, for a metallicity of 0.03.

論文

Examination of the surrogate ratio method for the determination of the $$^{93}$$Zr(n,$$gamma$$)$$^{94}$$Zr cross section with $$^{90,92}$$Zr($$^{18}$$O,$$^{16}$$O)$$^{92,94}$$Zr reactions

Yan, S. Q.*; Li, Z. H.*; Wang, Y. B.*; 西尾 勝久; 牧井 宏之; Su, J.*; Li, Y. J.*; 西中 一朗; 廣瀬 健太郎; Han, Y. L.*; et al.

Physical Review C, 94(1), p.015804_1 - 015804_5, 2016/07

 被引用回数:6 パーセンタイル:44.68(Physics, Nuclear)

The relative $$gamma$$-decay probability ratios of the neutron resonance states in $$^{94}$$Zr and $$^{92}$$Zr populated via two neutron transfer reactions, $$^{92}$$Zr($$^{18}$$O,$$^{16}$$O)$$^{94}$$Zr and $$^{90}$$Zr($$^{18}$$O,$$^{16}$$O)$$^{92}$$Zr, have been measured to test the validity of the surrogate ratio method (SRM) in determining the (n,$$gamma$$) reaction cross section. The cross sections of the $$^{93}$$Zr(n,$$gamma$$)$$^{94}$$Zr reaction are derived from the experimentally obtained ratios and the cross sections of the $$^{91}$$Zr(n,$$gamma$$)$$^{92}$$Zr reaction in the equivalent neutron energy range of $$E_{rm n}$$ = 0 - 8 MeV. The deduced cross sections of $$^{93}$$Zr(n,$$gamma$$)$$^{94}$$Zr reaction agree with the directly measured ones in the low-energy region, and with the evaluated ENDF/B-VII.1 data at higher energies of $$E_{rm n} >$$ 3 MeV. The agreement supports the concept of the SRM method to indirectly determine the (n,$$gamma$$) reaction cross sections.

論文

EBR-II passive safety demonstration tests benchmark analyses; Phase 2

Briggs, L.*; Monti, S.*; Hu, W.*; Sui, D.*; Su, G. H.*; Maas, L.*; Vezzoni, B.*; Partha Sarathy, U.*; Del Nevo, A.*; Petruzzi, A.*; et al.

Proceedings of 16th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-16) (USB Flash Drive), p.3030 - 3043, 2015/08

IAEA主催の「EBR-II炉停止のための熱除去試験に係るベンチマーク解析」研究共同プロジェクトは4年計画のうち3年目となっている。本プロジェクトには11ヶ国19機関がEBR-IIで行われた炉停止のための熱除去試験の内最も厳しい過渡試験の内の2ケースについて解析を実施してきた。ベンチマーク仕様に基づき炉心及び1次主冷却系の解析モデルを構築し解析を実施した。本プロジェクトのPhese 1ではブラインド解析が実施され測定データと比較・評価された。Phase 2では、Phese 1で試験データと合わなかった箇所を検討し解析モデルの改良を実施した。本論文では、最新の解析結果及び残された作業の実施方針を記載した。

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