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Pb and 
Bi in proton-induced reactions near 100 MeVIwamoto, Hiroki; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Ishi, Yoshihiro*; Uesugi, Tomonori*; Yashima, Hiroshi*; Nishio, Katsuhisa; Sugihara, Kenta*; 
elik, Y.*; et al.
Nuclear Instruments and Methods in Physics Research B, 544, p.165107_1 - 165107_15, 2023/11
Times Cited Count：0 Percentile：0.02(Instruments & Instrumentation)The lack of double-differential cross-section (DDX) data for neutron production below the incident proton energy of 200 MeV hinders the validation of spallation models in technical applications, such as research and development of accelerator-driven systems (ADSs). The present study aims to obtain experimental DDX data for ADS spallation target materials in this energy region and identify issues related to the spallation models by comparing them with the analytical predictions. The DDXs for the (
) reactions of Pb and Bi in the 100-MeV region were measured over an angular range of 30
to 150 using the time-of-flight method. The measurements were conducted at Kyoto University utilizing the FFAG accelerator. The DDXs obtained were compared with calculation results from Monte Carlo-based spallation models and the evaluated nuclear data library, JENDL-5. Comparison between the measured DDX and analytical values based on the spallation models and evaluated nuclear data library indicated that, in general, the CEM03.03 model demonstrated the closest match to the experimental values. Additionally, the comparison highlighted several issues that need to be addressed in order to improve the reproducibility of the proton-induced neutron-production DDX in the 100 MeV region by these spallation models and evaluated nuclear data library.
Sugihara, Kenta; Onodera, Naoyuki; Idomura, Yasuhiro; Yamashita, Susumu
JAEA-Research 2023-006, 47 Pages, 2023/10
JAEA-Research-2023-006.pdf:3.28MB
This report presents a new surface capturing method based on the phase field model for gas-liquid two-phase flows simulation. In the conventional phase field model, the interface correction strength parameter was determined from the maximum flow velocity in the computational domain, but because the interface correction was applied uniformly to the entire space, it was also applied to locations that did not require correction. In the new method, the phase field parameter or the intensity of the phase field model is extended to have a spatial distribution, allowing us to set the optimal parameters depending on the local flow velocity fields. We also propose a method to derive the optimal phase field parameter based on systematic parameter scans using error analysis of the interface advection test and bubble rising calculations. Through benchmark tests of gas-liquid two-phase flows, the proposed model is verified, and it is shown that the proposed model has higher accuracy than the conventional phase field model.
Iwamoto, Hiroki; Nakano, Keita; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Sugihara, Kenta*; Nishio, Katsuhisa; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; et al.
EPJ Web of Conferences, 284, p.01023_1 - 01023_4, 2023/05
Times Cited Count：0 Percentile：0.21(Nuclear Science & Technology)For accurate prediction of neutronic characteristics for accelerator-driven systems (ADS) and a source term of spallation neutrons for reactor physics experiments for the ADS at Kyoto University Critical Assembly (KUCA), we have launched an experimental program to measure nuclear data on ADS using the Fixed Field Alternating Gradient (FFAG) accelerator at Kyoto University. As part of this program, the proton-induced double-differential thick-target neutron-yields (TTNYs) and cross-sections (DDXs) for iron, lead, and bismuth have been measured with the time-of-flight (TOF) method. For each measurement, the target was installed in a vacuum chamber on the beamline and bombarded with 107-MeV proton beams accelerated from the FFAG accelerator. Neutrons produced from the targets were detected with stacked, small-sized neutron detectors for several angles from the incident beam direction. The TOF spectra were obtained from the detected signals and the FFAG kicker magnet's logic signals, where gamma-ray events were eliminated by pulse shape discrimination. Finally, the TTNYs and DDXs were obtained from the TOF spectra by relativistic kinematics. The measured TTNYs and DDXs were compared with calculations by the Monte Carlo transport code PHITS with its default physics model of INCL version 4.6 combined with GEM and those with the JENDL-4.0/HE nuclear data library.
Iwamoto, Hiroki; Nakano, Keita; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Sugihara, Kenta; Nishio, Katsuhisa; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; et al.
Journal of Nuclear Science and Technology, 60(4), p.435 - 449, 2023/04
Times Cited Count：3 Percentile：68.71(Nuclear Science & Technology)Double-differential thick target neutron yields (TTNYs) for Fe, Pb, and Bi targets induced by 107-MeV protons were measured using the fixed-field alternating gradient accelerator at Kyoto University for research and development of accelerator-driven systems (ADSs) and fundamental ADS reactor physics research at the Kyoto University Critical Assembly (KUCA). Note that TTNYs were obtained with the time-of-flight method using a neutron detector system comprising eight neutron detectors; each detector has a small NE213 liquid organic scintillator and photomultiplier tube. The TTNYs obtained were compared with calculation results using Monte Carlo-based spallation models (i.e., INCL4.6/GEM, Bertini/GEM, JQMD/GEM, and JQMD/SMM/GEM) and the evaluated high-energy nuclear data library, i.e., JENDL-4.0/HE, implemented in the particle and heavy iontransport code system (PHITS). All models, including JENDL-4.0/HE, failed to predict high-energy peaks at a detector angle of 5. Comparing the energy- and angle-integrated spallation neutron yields at energies of 
20 MeV estimated using the measured TTNYs and the PHITS indicated that INCL4.6/GEM would be suitable for the Monte Carlo transport simulation of ADS reactor physics experiments at the KUCA.
Watanabe, Seiya*; Kawahara, Jun*; Aoki, Takayuki*; Sugihara, Kenta; Takase, Shinsuke*; Moriguchi, Shuji*; Hashimoto, Hirotada*
Engineering Applications of Computational Fluid Mechanics, 17(1), p.2211143_1 - 2211143_23, 2023/00
Times Cited Count：1 Percentile：61.52(Engineering, Multidisciplinary)In tsunami inundations or slope disasters of heavy rain, a lot of floating debris or driftwood logs are included in the flows. The damage to structures from solid body impacts is more severe than the damage from the water pressure. In order to study free-surface flows that include floating debris, developing a high-accurate simulation code of free-surface flows with high performance for large-scale computations is desired. We propose the single-phase free-surface flow model based on the cumulant lattice Boltzmann method coupled with a particle-based rigid body simulation. The discrete element method calculates the contact interaction between solids. An octree-based AMR (Adaptive Mesh Refinement) method is introduced to improve computational accuracy and time-to-solution. High-resolution grids are assigned near the free surfaces and solid boundaries. We conducted two kinds of tsunami flow experiments in the 15 and 70 m water tanks at Hachinohe Institute of Technology and Kobe University to validate the accuracy of the proposed model. The simulation results have shown good agreement with the experiments for the drifting speed, the number of trapped wood pieces, and the stacked angles.
Sato, Tatsuhiko; Iwamoto, Yosuke; Hashimoto, Shintaro; Ogawa, Tatsuhiko; Furuta, Takuya; Abe, Shinichiro; Kai, Takeshi; Matsuya, Yusuke; Matsuda, Norihiro; Hirata, Yuho; et al.
Journal of Nuclear Science and Technology, 9 Pages, 2023/00
Times Cited Count：5 Percentile：98.08(Nuclear Science & Technology)The Particle and Heavy Ion Transport code System (PHITS) is a general-purpose Monte Carlo radiation transport code that can simulate the behavior of most particle species with energies up to 1 TeV (per nucleon for ions). Its new version, PHITS3.31, was recently developed and released to the public. In the new version, the compatibility with high-energy nuclear data libraries and the algorithm of the track-structure modes have been improved. In this paper, we summarize the upgraded features of PHITS3.31 with respect to the physics models, utility functions, and application software introduced since the release of PHITS3.02 in 2017.
Sugihara, Kenta; Onodera, Naoyuki; Idomura, Yasuhiro; Yamashita, Susumu
Dai-36-Kai Suchi Ryutai Rikigaku Shimpojiumu Koen Rombunshu (Internet), 5 Pages, 2022/12
The conventional Allen-Cahn type multi-phase field method was modified to conserve not only the sum of the masses of all phases but also the mass of each phase. The interface advection calculations within a two-dimensional rotational velocity field were performed as a verification problem, and the conservation was successfully achieved. The proposed method was used to calculate the horizontally aligned pair of bubbles rising, and it was found that the bouncing phenomenon between bubbles can be calculated at 1/50 resolution of the high-resolution calculation by Zhang et al. using the volume of fluid method.
Sugihara, Kenta; Onodera, Naoyuki; Idomura, Yasuhiro; Yamashita, Susumu
Keisan Kogaku Koenkai Rombunshu (CD-ROM), 27, 5 Pages, 2022/06
The phase-field method has been successfully applied to various multi-phase flow problems as an interface tracking method for gas-liquid interfaces. However, the accuracy of the phase-field method depends on hyper-parameters, which are empirically adjusted for each problem. The phase-field method sustains sharp interfaces by the balance between the numerical viscosity of the advection term and the interface modification by the diffusion and anti-diffusion terms. Based on this fact, we propose a method for deriving the optimal hyper-parameters in a non-empirical manner by performing a basic error analysis of the interface advection.
Yamada, Tomonori; Yamashita, Susumu; Sugihara, Kenta; Muramatsu, Toshiharu
Purazuma, Kaku Yugo Gakkai-Shi, 89(7), p.500 - 506, 2013/08
no abstracts in English
Yamamoto, Masato*; Kimura, Akihiko*; Onizawa, Kunio; Yoshimoto, Kentaro*; Ogawa, Takuya*; Chiba, Atsushi*; Hirano, Takashi*; Sugihara, Takuji*; Sugiyama, Masanari*; Miura, Naoki*; et al.
Proceedings of 2012 ASME Pressure Vessels and Piping Conference (PVP 2012) (DVD-ROM), 7 Pages, 2012/07
Master curve (MC) approach for the fracture toughness evaluation is expected to be a powerful tool to assess the structural integrity of reactor pressure vessels (RPVs). In order to get sufficient number of reliable data for the MC approach from broken halves of surveillance test specimens for RPVs, the use of miniature specimens is necessary. For this purpose, a round robin test program on the miniature compact tension specimens (Mini-CT) of 4 mm thick for the MC approach of a Japanese RPV steel has been launched with the participation of academia, industries and a research institute in Japan. The program aims to verify the reliability of experimental data from Mini-CT, and to pick out further investigation items to be solved. As the first step of this program, four institutes carried out MC testing and evaluation using common test procedure and specimens. Valid reference temperature T
was successfully obtained in each institute. However, the T values showed large differences with maximum of 34C. It was indicated on the reason of difference that there is a strong correlation between the T values and loading rate, which was selected by each institute per test standard.
Sugihara, Kenta; Nakamura, Yasuyuki; Ogawa, Takemitsu; Muramatsu, Toshiharu
Proceedings of 20th International Conference on Nuclear Engineering and the ASME 2012 Power Conference (ICONE-20 & POWER 2012) (DVD-ROM), 7 Pages, 2012/07
Numerical simulation code, based on multi-phase thermohydraulics, has been being developed with a goal of a control and prediction for the laser cutting process. A thermohydraulic numerical simulation of the laser steel cutting was carried out to confirm an assist gas and sweep velocity effect to the cutting performance. The performance was evaluated, based on temperature profile and cutting front formation. Simulation results were as follows. If there was no effect of dross ejection by assist gas, a laser light was absorbed into molten steel stagnated in the kerf. Therefore, there was less laser heat input to a solid surface directly. Then, heat transport to the back side of steel plate got delayed. In the case of faster sweep velocity, delay of heat conduction and failure cut were confirmed at behind the cut starting position of the steel plate. Failure cut at the position was observed in our experiments. From these results, it was concluded that the thermohydraulics in the kerf takes important role for not only dross ejection but also promotion of heat input at solid surface.
Ogawa, Takemitsu; Sugihara, Kenta; Nakamura, Yasuyuki; Muramatsu, Toshiharu; Shamoto, Hideyasu*
no journal, ,
no abstracts in English
Yamada, Tomonori; Shobu, Takahisa; Yamashita, Susumu; Ogawa, Takemitsu; Sugihara, Kenta; Nishimura, Akihiko; Muramatsu, Toshiharu
no journal, ,
no abstracts in English
Sugihara, Kenta; Ogawa, Takemitsu; Nakamura, Yasuyuki; Muramatsu, Toshiharu
no journal, ,
A thermohydraulic numerical simulation of the laser steel cutting was carried out to confirm an assist gas and sweep velocity effect to the cutting performance. The performance was evaluated, based on temperature profile and cutting front formation. Simulation results were as follows. If there was no effect of dross ejection by assist gas, a laser light was absorbed into molten steel stagnated in the kerf. Therefore, there was less laser heat input to a solid surface directly. Then, heat transport to the back side of steel plate got delayed. In the case of faster sweep velocity, delay of heat conduction and failure cut were confirmed at behind the cut starting position of the steel plate. Failure cut at the position was observed in our experiments. From these results, it was concluded that the thermohydraulics in the kerf takes important role for not only dross ejection but also promotion of heat input at solid surface.
Yamada, Tomonori; Yamashita, Susumu; Sugihara, Kenta; Ogawa, Takemitsu; Shobu, Takahisa; Muramatsu, Toshiharu
no journal, ,
no abstracts in English
Muramatsu, Toshiharu; Sugihara, Kenta; Ogawa, Takemitsu; Nakamura, Yasuyuki; Sano, Kazuya
no journal, ,
no abstracts in English
Sugihara, Kenta; Nakamura, Yasuyuki; Ogawa, Takemitsu; Sano, Kazuya; Muramatsu, Toshiharu
no journal, ,
Numerical simulation code, based on multi-phase thermohydraulics, has been being developed with a goal of a control and prediction for the laser cutting process. A thermohydraulic numerical simulation of the laser steel cutting was carried out to confirm an assist gas and sweep velocity effect to the cutting performance. The performance was evaluated, based on temperature profile and cutting front formation. From results of numerical simulation, it was concluded that the thermohydraulics in the kerf takes important role for not only dross ejection but also promotion of heat input at solid surface.
Daido, Hiroyuki; Yamada, Tomonori; Yamashita, Susumu; Sugihara, Kenta; Nishimura, Akihiko; Muramatsu, Toshiharu; Shobu, Takahisa
no journal, ,
no abstracts in English
Yamada, Tomonori; Yamashita, Susumu; Shobu, Takahisa; Nishimura, Akihiko; Ogawa, Takemitsu; Sugihara, Kenta; Shamoto, Hideyasu*
no journal, ,
no abstracts in English
Hanari, Toshihide; Sugihara, Kenta; Ogawa, Takemitsu; Muramatsu, Toshiharu
no journal, ,
no abstracts in English
