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Machida, Masahiko; Yamada, Susumu; Kim, M.; Tanaka, Satoshi*; Tobita, Yasuhiro*; Iwata, Ayako*; Aoki, Yuto; Aoki, Kazuhisa; Yanagisawa, Kenichi*; Yamaguchi, Takashi; et al.
RIST News, (70), p.3 - 22, 2024/09
Inside the Fukushima Daiichi Nuclear Power Plant (1F), there are many locations with high radiation levels due to contamination by radioactive materials that leaked from the reactor. These pose a significant obstacle to the smooth progress of decommissioning work. To help solve this issue, the Japan Atomic Energy Agency (JAEA), under a subsidy from the Ministry of Economy, Trade, and Industry's decommissioning and contaminated water management project, is conducting research and development on digital technologies to improve the radiation environment inside the decommissioning site. This project, titled "Development of Technology to Improve the Environment Inside Reactor Buildings (Enhancing Digital Technology for Environment and Source Distribution to Reduce Radiation Exposure)," began in April of FY 2023. In this project, the aim is to develop three interconnected systems: FrontEnd, Pro, and BackEnd. The FrontEnd system, based on the previously developed 3D-ADRES-Indoor (prototype) from FY 2021-2022, will be upgraded to a high-speed digital twin technology usable on-site. The Pro system will carry out detailed analysis in rooms such as the new office building at 1F, while the BackEnd system will serve as a database to centrally manage the collected and analyzed data. This report focuses on the FrontEnd system, which will be used on-site. After point cloud measurement, the system will quickly create a 3D mesh model, estimate the radiation source from dose rate measurements, and refine the position and intensity of the estimated source using recalculation techniques (re-observation instructions and re-estimation). The results of verification tests conducted on Unit 5 are also presented. Furthermore, the report briefly discusses the future research and development plans for this project.
Shimodaira, Masaki; Yamaguchi, Yoshihito; Iwata, Keiko; Katsuyama, Jinya; Chimi, Yasuhiro
Proceedings of ASME 2024 Pressure Vessels & Piping Conference (PVP 2024) (Internet), 10 Pages, 2024/07
no abstracts in English
Giachino, A.*; Hosaka, Atsushi; Santopinto, E.*; Takeuchi, Sachiko*; Takizawa, Makoto*; Yamaguchi, Yasuhiro*
Physical Review D, 108(7), p.074012_1 - 074012_6, 2023/10
Times Cited Count：8 Percentile：73.87(Astronomy & Astrophysics)no abstracts in English
Machida, Masahiko; Yamada, Susumu; Kim, M.; Okumura, Masahiko; Miyamura, Hiroko; Shikaze, Yoshiaki; Sato, Tomoki*; Numata, Yoshiaki*; Tobita, Yasuhiro*; Yamaguchi, Takashi; et al.
RIST News, (69), p.2 - 18, 2023/09
The contamination of radioactive materials leaked from the reactor has resulted in numerous hot spots in the Fukushima Daiichi Nuclear Power Station (1F) building, posing obstacles to its decommissioning. In order to solve this problem, JAEA has conducted research and development of the digital technique for inverse estimation of radiation source distribution and countermeasures against the estimated source in virtual space for two years from 2021 based on the subsidy program "Project of Decommissioning and Contaminated Water Management" performed by the funds from the Ministry of Economy, Trade and Industry. In this article, we introduce the results of the project and the plan of the renewal project started in April 2023. For the former project, we report the derivative method for LASSO method considering the complex structure inside the building and the character of the source and show the result of the inverse estimation using the method in the real reactor building. Moreover, we explain the platform software "3D-ADRES-Indoor" which integrates these achievements. Finally, we introduce the plan of the latter project.
Shimizu, Kazuyuki*; Toda, Hiroyuki*; Fujihara, Hiro*; Yamaguchi, Masatake; Uesugi, Masayuki*; Takeuchi, Akihisa*; Nishijima, Masahiko*; Kamada, Yasuhiro*
Corrosion, 79(8), p.818 - 830, 2023/08
Times Cited Count：3 Percentile：28.81(Materials Science, Multidisciplinary)7xxx aluminum alloys are representative high-strength aluminum alloys; however, mechanical property degradation due to hydrogen hinders further strengthening. We propose the dispersion of Mn-based second-phase particles as a novel technique for preventing 7xxx aluminum alloy hydrogen embrittlement. In this study, the deformation and fracture behaviors of high hydrogen 7xxx alloys containing 0.0% Mn and 0.6% Mn are observed in situ using synchrotron radiation X-ray tomography. The obtained macroscopic hydrogen embrittlement is quantitatively analyzed based on hydrogen partitioning in alloys. Adding 0.6% Mn, generating second-phase particles with high hydrogen trapping abilities, significantly suppresses hydrogen-induced quasicleavage fracture.
Nii, Keisuke*; Ida, Yoshiaki*; Ueda, Hideki*; Yamaguchi, Takanori*; Kabumoto, Hiroshi; Kamiya, Junichiro; Kondo, Yasuhiro; Tamura, Jun; Harada, Hiroyuki; Matsui, Yutaka; et al.
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.601 - 604, 2023/01
no abstracts in English
la the nuclear forceYamaguchi, Yasuhiro; Yasui, Shigehiro*; Hosaka, Atsushi
Physical Review D, 106(9), p.094001_1 - 094001_16, 2022/11
Times Cited Count：2 Percentile：21.84(Astronomy & Astrophysics)Machida, Masahiko; Yamada, Susumu; Kim, M.; Okumura, Masahiko; Miyamura, Hiroko; Malins, A.; Shikaze, Yoshiaki; Sato, Tomoki*; Numata, Yoshiaki*; Tobita, Yasuhiro*; et al.
RIST News, (68), p.3 - 19, 2022/09
no abstracts in English
Katayama, Ryo*; Kako, Eiji*; Yamaguchi, Seiya*; Michizono, Shinichiro*; Umemori, Kensei*; Kondo, Yasuhiro
Physical Review Accelerators and Beams (Internet), 25(2), p.021601_1 - 021601_18, 2022/02
Times Cited Count：3 Percentile：46.68(Physics, Nuclear)We investigated the feasibility on the application of a superconducting radio frequency (SRF) niobium cavity to an accelerator-based neutron source for boron neutron capture therapy (BNCT). This paper presents a first feasibility study on the application of a SRF niobium cavity to an accelerator-based neutron source for BNCT, assuming that a superconducting radio frequency quadrupole (SC-RFQ) composed of pure bulk niobium at 4.2 K accelerates the proton/deuteron beams to a beryllium or lithium target for the neutron production of BNCT. We evaluated the feasibility on the following three criteria: comparison of the cooling capacity of the refrigerator to the amount of heat, power consumption of AC, and size of the BNCT system. This study demonstrated that the application of the SRF cavity for the rf-linac-based neutron source of BNCT is feasible, and the 2.5 MeV deuteron SC-RFQ and lithium target system is the optimum.
(3872) revisited; The Roles of OPEP and the quark degrees of freedomTakeuchi, Sachiko*; Yamaguchi, Yasuhiro; Hosaka, Atsushi; Takizawa, Makoto*
Few-Body Systems, 62(4), p.77_1 - 77_4, 2021/12
Times Cited Count：2 Percentile：23.00(Physics, Multidisciplinary)
and 
as interfering 
and 
threshold cuspsNakamura, Satoshi*; Hosaka, Atsushi; Yamaguchi, Yasuhiro
Physical Review D, 104(9), p.L091503_1 - L091503_8, 2021/11
Times Cited Count：24 Percentile：83.73(Astronomy & Astrophysics)Nii, Keisuke*; Ida, Yoshiaki*; Ueda, Hideki*; Yamaguchi, Takanori*; Kabumoto, Hiroshi; Kamiya, Junichiro; Kondo, Yasuhiro; Tamura, Jun; Harada, Hiroyuki; Matsui, Yutaka; et al.
Proceedings of 18th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.334 - 337, 2021/10
no abstracts in English
Yamaguchi, Yasuhiro; Garc
a-Tecocoatzi, H.*; Giachino, A.*; Hosaka, Atsushi; Santopinto, E.*; Takeuchi, Sachiko*; Takizawa, Makoto*
Few-Body Systems, 62(3), p.33_1 - 33_7, 2021/09
Times Cited Count：1 Percentile：12.31(Physics, Multidisciplinary)We investigate the hidden-charm pentaquarks as hadronic molecules of 
and 
coupled to a 
compact core by employing an interaction satisfying the heavy quark and chiral symmetries. Our model can consistently explain the masses and decay widths of 
, 
and 
with spin parity assignments 
, 
and 
, respectively. We find that the mass ordering is dominantly determined by the short-range interaction given by coupling to the compact core, while the decay widths by the tensor force of the one-pion exchange.
pentaquarks in hadron dynamicsYamaguchi, Yasuhiro
Genshikaku Kenkyu, 65(2), p.19 - 30, 2021/03
Recently exotic hadrons including a 
component have been reported in experimental researches. The exotic states cannot be explained by the ordinary hadron picture, namely a baryon as a three-quark state, and a meson as a quark-antiquark state, while a multiquark component would be dominated in their structure. We investigate the pentaquarks reported by LHCb as a 
hadronic molecule coupling to a 
compact core. The coupling to the core plays an short-range interaction (
potential) generating an attraction. In addition, the one pion exchange potential (OPEP) as a long-range interaction is introduced. Our model can consistently explain the masses and widths of the states reported by LHCb in 2019. The role of the interactions employed is investigated, and we find that the structure of the energy level is determined by the potential, while the decay width by the tensor term of the OPEP.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：54 Percentile：96.05(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
Yamaguchi, Yasuhiro; Yamanaka, Nodoka*
Physical Review D, 103(1), p.013001_1 - 013001_20, 2021/01
Times Cited Count：41 Percentile：93.25(Astronomy & Astrophysics)We evaluate the electric dipole moment (EDM) of charged leptons in the standard model. We first prove that, at the quark-gluon level, it is suppressed due to the GIM mechanism. We then calculate the hadronic long distance contribution generated by vector mesons at one-loop level. The 
= 1 weak hadronic interaction is derived using the factorization, and the strong interaction is modeled by the hidden local symmetry framework. We find that the EDMs of charged leptons obtained from this hadronic mechanism are much larger than the perturbative four-loop level quark-gluon process, by several orders of magnitude.
Yamaguchi, Yasuhiro; Yamanaka, Nodoka*
Physical Review Letters, 125(24), p.241802_1 - 241802_7, 2020/12
Times Cited Count：45 Percentile：91.21(Physics, Multidisciplinary)We reevaluate the electric dipole moment (EDM) of charged leptons in the standard model using hadron effective models. We find unexpectedly large EDM generated by the hadron level long-distance effect, 
, 
, and 
cm, with an error bar of 70%, exceeding the conventionally known four-loop level elementary contribution by several orders of magnitude.
within the Regge-plus-resonance modelSkoupil, D.*; Yamaguchi, Yasuhiro
Physical Review D, 102(7), p.074009_1 - 074009_19, 2020/10
Times Cited Count：1 Percentile：6.71(Astronomy & Astrophysics)
-meson photoproduction off the proton is studied, which will be useful tool to investigate the charmed-hadron properties. Since many parameters are still unknown in the charmed-hadron photoproduction, we employ the Regge-plus-resonance model, where there are limited number of parameters needed to be adjusted. The background part is modeled within the Regge model with the 
trajectories being exchanged in the 
channel or 
trajectories in the 
channel. These contributions create the cross sections which are smooth functions of energies. We also introduce the exchange of the hidden-pentaquarks in the 
channel that create the sharp peak in the cross section predictions.
Yamaguchi, Yasuhiro*; Hosaka, Atsushi; Takeuchi, Sachiko*; Takizawa, Makoto*
Journal of Physics G; Nuclear and Particle Physics, 47(5), p.053001_1 - 053001_67, 2020/05
Times Cited Count：62 Percentile：89.35(Physics, Nuclear) pentaquarks with chiral tensor and quark dynamicsYamaguchi, Yasuhiro; Garca-Tecocoatzi, H.*; Giachino, A.*; Hosaka, Atsushi; Santopinto, E.*; Takeuchi, Sachiko*; Takizawa, Makoto*
Physical Review D, 101(9), p.091502_1 - 091502_7, 2020/05
Times Cited Count：60 Percentile：94.93(Astronomy & Astrophysics)We investigate the hidden-charm pentaquarks as hadronic molecules of and coupled to a compact core by employing an interaction satisfying the heavy quark and chiral symmetries. Our model can consistently explain the masses and decay widths of , and with spin parity assignments , and , respectively. We find that the mass ordering is dominantly determined by the short-range interaction given by coupling to the compact core, while the decay widths by the tensor force of the one-pion exchange.
