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Al
; Impact of the U 
states on the electronic structure of UPdAlFujimori, Shinichi; Takeda, Yukiharu; Yamagami, Hiroshi; Posp
il, J.*; Yamamoto, Etsuji; Haga, Yoshinori
Physical Review B, 105(11), p.115128_1 - 115128_6, 2022/03
Zhao, Y.*; Suzuki, T.*; Iimori, T.*; Kim, H.-W.*; Ahn, J. R.*; Horio, Masafumi*; Sato, Yusuke*; Fukaya, Yuki; Kanai, T.*; Okazaki, K.*; et al.
Physical Review B, 105(11), p.115304_1 - 115304_8, 2022/03
no abstracts in English
Tobita, Minoru*; Haraga, Tomoko; Endo, Tsubasa*; Omori, Hiroyuki*; Mitsukai, Akina; Aono, Ryuji; Ueno, Takashi; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2021-013, 30 Pages, 2021/12
JAEA-Data-Code-2021-013.pdf:1.47MB
Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until the beginning of disposal. In order to contribute to this work, we collected and analyzed concrete samples generated from JPDR facility. In this report, we summarized the radioactivity concentrations of 21 radionuclides (
H, 
C, 
Cl, 
Ca, 
Co, 
Ni, 
Sr, 
Nb, 
Ag, 
Cs, 
Eu, 
Eu, 
Ho, 
U, 
U, Pu, 
Pu, 
Pu, 
Am, 
Am, 
Cm) which were obtained from radiochemical analysis of the samples in fiscal year 2018-2019.
Okawa, Tomio*; Mori, Shoji*; Liu, W.*; Ose, Yasuo*; Yoshida, Hiroyuki; Ono, Ayako
Nihon Genshiryoku Gakkai-Shi ATOMO
, 63(12), p.820 - 824, 2021/12
The evaluation method of the critical heat flux based on the mechanism is needed for the efficient design and development of fuel in reactors and the appropriate safety evaluation. In this paper, the current researches relating to the mechanism of the critical heat flux are reviewed, and the issue to be considered in the future are discussed.
layers in the triple-layer cuprate BiSrCaCuO
studied by angle-resolved photoemission spectroscopyIdeta, Shinichiro*; Johnston, S.*; Yoshida, Teppei*; Tanaka, Kiyohisa*; Mori, Michiyasu; Anzai, Hiroaki*; Ino, Akihiro*; Arita, Masashi*; Namatame, Hirofumi*; Taniguchi, Masaki*; et al.
Physical Review Letters, 127(21), p.217004_1 - 217004_6, 2021/11
P studied by soft X-ray photoemission spectroscopyKawasaki, Ikuto; Kobata, Masaaki; Fujimori, Shinichi; Takeda, Yukiharu; Yamagami, Hiroshi; Hedo, Masato*; Nakama, Takao*; Onuki, Yoshichika*
Physical Review B, 104(16), p.165124_1 - 165124_8, 2021/10
Times Cited Count：0Okita, Hidefumi; Tamura, Fumihiko; Yamamoto, Masanobu; Nomura, Masahiro; Shimada, Taihei; Yoshii, Masahito*; Omori, Chihiro*; Hara, Keigo*; Hasegawa, Katsushi*; Sugiyama, Yasuyuki*; et al.
Proceedings of 18th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.840 - 844, 2021/10
The J-PARC RCS employs the dual-harmonic operation, in which the fundamental and the second harmonic RF voltages are used for the beam acceleration. The each harmonic voltage and phase applied for the acceleration gaps are controlled by the multiharmonic vector RF voltage control system using the signal from the cavity gap voltage monitor equipped with the one of the acceleration gaps of the each RF cavity. Since the bunch shape varies depending on the relative phase of each harmonic, it is important to evaluate the frequency response of the cavity gap voltage monitor. The measurements of frequency response of the cavity gap voltage monitor and beam tracking simulation considering the measurement were carried out. As a result, it was confirmed that the bunch shape of the beam tracking simulation reproduces the one measured at the 1MW beam operation well. The details of the frequency response measurement, the beam tracking simulation and the discussion of the cavity gap voltage monitor circuit are reported.
Tamura, Fumihiko; Sugiyama, Yasuyuki*; Yoshii, Masahito*; Yamamoto, Masanobu; Okita, Hidefumi; Omori, Chihiro*; Nomura, Masahiro; Shimada, Taihei; Hasegawa, Katsushi*; Hara, Keigo*; et al.
Proceedings of 18th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.170 - 174, 2021/10
A stable and precise LLRF (Low Level RF) control system is indispensable for acceleration of high intensity proton beam in the J-PARC RCS. The original LLRF control system had been operated without major problems for more than ten years since the start of operation of the RCS, while maintenance of the system became difficult due to the obsolesce of the old FPGAs in the modules. We developed and installed the next-generation LLRF control system based on MTCA.4. The key function of the system is the multiharmonic vector rf voltage control feedback. We describe the system overview and the commissioning results. The performance of the beam loading compensation is significantly improved.
Nomura, Masahiro; Okita, Hidefumi; Shimada, Taihei; Tamura, Fumihiko; Yamamoto, Masanobu; Furusawa, Masashi*; Sugiyama, Yasuyuki*; Hasegawa, Katsushi*; Hara, Keigo*; Omori, Chihiro*; et al.
Proceedings of 18th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.80 - 82, 2021/10
no abstracts in English
electron paramagnetic resonanceSaio, Tomohide*; Hiramatsu, Soya*; Asada, Mizue*; Nakagawa, Hiroshi; Shimizu, Kazumi*; Kumeta, Hiroyuki*; Nakamura, Toshikazu*; Ishimori, Koichiro*
Biophysical Journal, 120(15), p.2943 - 2951, 2021/08
Times Cited Count：0 Percentile：0.01(Biophysics)A rigid double-arm lanthanide tag was utilized in electron paramagnetic resonance spectroscopy to measure the distance between two specific points on a protein, and conformational states and distribution of a multi-domain protein enzyme MurD was investigated. Although the previous crystallographic and NMR studies have reported the three distinct conformational states of MurD, our data unveiled that the protein exists in much more variety of conformational states in the absence of the ligand. Given the fact that MurD is one of the potent drug target for infectious diseases, the finding in this study will provide important structural basis for drug development.
Tamura, Fumihiko; Omori, Chihiro*; Yoshii, Masahito*; Sugiyama, Yasuyuki*
Proceedings of 12th International Particle Accelerator Conference (IPAC 21) (Internet), p.3023 - 3026, 2021/08
The J-PARC MR delivers the high intensity proton beams for the neutrino experiment. The new Intermediate Water Cherenkov Detector (IWCD) will be constructed for the future neutrino experiment and a low peak time structure is desired by the IWCD. Thus, we consider bunch manipulation at flattop of the MR for reducing the peak current. The manipulation should be quickly done to minimize the loss of the beam power. Also, the beam gap must be kept for the rise time of the extraction kicker. We propose a non-adiabatic bunch manipulation using the multiharmonic rf voltage. By using the neighbor harmonic of the accelerating harmonic, the first and eighth bunches can be decelerated and accelerated, respectively. After a certain period, the rf phase is flipped to 
for debunching. Thanks to the initial deceleration and acceleration, the beam gap for the kickers is kept. We present the concept and the longitudinal simulation result.
Okita, Hidefumi; Tamura, Fumihiko; Yamamoto, Masanobu; Nomura, Masahiro; Shimada, Taihei; Yoshii, Masahito*; Omori, Chihiro*; Sugiyama, Yasuyuki*; Hasegawa, Katsushi*; Hara, Keigo*; et al.
Proceedings of 12th International Particle Accelerator Conference (IPAC 21) (Internet), p.3020 - 3022, 2021/08
In the J-PARC RCS, the dual-harmonic operation, in which each RF cavity is driven by superposition of the fundamental accelerating voltage and the second harmonic voltage, are employed. The dual-harmonic-operation significantly improves the bunching factor and is indispensable for acceleration of the high intensity beams. The original LLRF control system was replaced with the new system in 2019, which can control the amplitudes of the higher harmonics as well as the fundamental and second harmonics. Therefore we consider to use additionally the third harmonic voltage for further improvement of the bunching factor during acceleration. By the triple-harmonic operation, the flat RF bucket can be realized and beam simulation results indicate that the bunching factor can be improved about 30% at maximum. In this presentation, we describe the longitudinal simulation studies of the triple-harmonic operation. Also the preliminary test results are presented.
Yamamoto, Masanobu; Okita, Hidefumi; Nomura, Masahiro; Shimada, Taihei; Tamura, Fumihiko; Furusawa, Masashi*; Hara, Keigo*; Hasegawa, Katsushi*; Omori, Chihiro*; Sugiyama, Yasuyuki*; et al.
Proceedings of 12th International Particle Accelerator Conference (IPAC 21) (Internet), p.1884 - 1886, 2021/08
Tetrode vacuum tubes in J-PARC RCS are used under a reduced filament voltage condition compared with the rating value to prolong the tube lifetime. For the first time after 60,000 hour of operation in the RCS, one tube has reached the end of its life in 2020. Therefore, the reduced filament voltage works well because the tube has been running beyond an expected lifetime suggested by the tube manufacturer. However, the reduced filament voltage decreased the electron emission from the filament. Although the large amplitude of the anode current is necessary for the high intensity beam acceleration to compensate a wake voltage, a solid-state amplifier to drive a control grid circuit almost reaches the output power limit owing to the poor electron emission from the filament. We changed the filament voltage reduction rate from 15% to 5%. The required power of the solid-state amplifier was fairly reduced, whereas the accelerated beam power remained the same. We describe the measurement results of the vacuum tube parameters in terms of the filament voltage tuning.
Nishino, Saki; Tsuboi, Masatoshi; Okada, Jumpei; Saegusa, Yu; Omori, Kazuki; Yasuo, Kiyoshi; Seshimo, Kazuyoshi; Domura, Kazuyuki; Yamamoto, Masahiko
Nihon Hozen Gakkai Dai-17-Kai Gakujutsu Koenkai Yoshishu, p.541 - 548, 2021/07
no abstracts in English
Si in paramagnetic phase; Three-dimensional angle resolved photoelectron spectroscopy studyFujimori, Shinichi; Takeda, Yukiharu; Yamagami, Hiroshi; Yamamoto, Etsuji; Haga, Yoshinori
Electronic Structure (Internet), 3(2), p.024008_1 - 024008_8, 2021/06
Sanada, Yukihisa; Kurikami, Hiroshi; Funaki, Hironori; Yoshimura, Kazuya; Abe, Tomohisa; Ishida, Mutsushi*; Tanimori, Soichiro*; Sato, Rina
Nihon Genshiryoku Gakkai Wabun Rombunshi, 20(2), p.62 - 73, 2021/06
Japanese government starts to consider radiation protection in the "specific reconstruction reproduction base area" of which evacuation order will be lifted by 2023. It is essential to grab the present situations of radiation contamination and evaluate exposure dose in the area to realize the plan. Many surveys have evaluated the distributions of air dose rate and exposure dose has been estimated based on the results since the Fukushima Daiichi Nuclear Power Plant accident. Nevertheless, more detailed information on exposure is needed for the areas because its radiation level is relatively high. That is also to help make prudent evaluation plan. This study aimed to evaluate the detailed contamination situation there and estimate exposure dose with considering areal circumstances. Investigations were carried out for (1) airborne survey of air dose rate using an unmanned helicopter (2) evaluation of airborne radiocesium and (3) estimation of external/internal effective doses for typical activity patterns assumed.
Iizuka, Riko*; Goto, Hirotada*; Shito, Chikara*; Fukuyama, Ko*; Mori, Yuichiro*; Hattori, Takanori; Sano, Asami; Funakoshi, Kenichi*; Kagi, Hiroyuki*
Scientific Reports (Internet), 11(1), p.12632_1 - 12632_10, 2021/06
Times Cited Count：0 Percentile：0.01(Multidisciplinary Sciences)The Earth's core consist of Fe-Ni alloy with some light elements (H, C, O, Si, S etc.). Hydrogen (H) is the most abundant element in the universe and one of the promising candidates. In this study, we have investigated the effects of sulfur(S) on hydrogenation of iron-hydrous silicate system containing saturated water in the ideal composition of the primitive Earth. We observed a series of phase transitions of Fe, dehydration of the hydrous mineral, and formation of olivine and enstatite with increasing temperature. The FeS formed as the coexisting phase of Fe under high-pressure and temperature condition, but its unit cell volume did not increase, suggesting that FeS is hardly hydrogenated. Recovered samples exhibited that H and S can be incorporated into solid Fe, which lowers the melting temperature as Fe(H
)-FeS system. No detection of other light elements (C, O, Si) in solid Fe suggests that they dissolve into molten iron hydride and/or FeS in the later process of Earth's core-mantle differentiation.
Tamura, Fumihiko; Sugiyama, Yasuyuki*; Yoshii, Masahito*; Yamamoto, Masanobu; Okita, Hidefumi; Omori, Chihiro*; Nomura, Masahiro; Shimada, Taihei; Hasegawa, Katsushi*; Hara, Keigo*; et al.
Nuclear Instruments and Methods in Physics Research A, 999, p.165211_1 - 165211_11, 2021/05
Times Cited Count：0 Percentile：0.03(Instruments & Instrumentation)The low level rf (LLRF) control system has key roles for the stable acceleration of the high intensity beam. The original LLRF control system for the RCS of J-PARC has been working nicely without major issues for more than ten years since the operation of the RCS started in 2007. Due to the obsolescence of the key digital devices, it is difficult to maintain the original system for a longer period, therefore we developed the next-generation LLRF control system. All of the LLRF functions of the new system were tested and commissioned. In this article, we describe the commissioning of two key functions, the phase feedback and the multiharmonic vector rf voltage control feedback for twelve cavities. The commissioning methodologies and beam test results are presented. The stable acceleration of the high intensity beam at the design intensity of 
ppp is achieved. The next-generation LLRF control system has been successfully deployed and commissioned.
=1/2 one-dimensional Ising-like antiferromagnet BaCo
VO
in transverse magnetic fieldsOkutani, Akira*; Onishi, Hiroaki; Kimura, Shojiro*; Takeuchi, Tetsuya*; Kida, Takanori*; Mori, Michiyasu; Miyake, Atsushi*; Tokunaga, Masashi*; Kindo, Koichi*; Hagiwara, Masayuki*
Journal of the Physical Society of Japan, 90(4), p.044704_1 - 044704_9, 2021/04
Times Cited Count：0 Percentile：0(Physics, Multidisciplinary)Tsuchida, Daiki; Haraga, Tomoko; Tobita, Minoru*; Omori, Hiroyuki*; Omori, Takeshi*; Murakami, Hideaki*; Mitsukai, Akina; Aono, Ryuji; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2020-022, 34 Pages, 2021/03
JAEA-Data-Code-2020-022.pdf:1.74MB
Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until the beginning of disposal. In order to contribute to this work, we collected and analyzed concrete samples generated from JRR-3 and JPDR. In this report, we summarized the radioactivity concentrations of 22 radionuclides(H, C, Cl, Ca, Co, Ni, Sr, Nb, Ag, 
Ba, Cs, Eu, Eu, Ho, U, U, Pu, 
Pu, Am, Am, Cm) which were obtained from radiochemical analysis of the samples.
