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Nakazawa, Yuga*; Cicek, E.*; Ishida, Katsuhiko*; Futatsukawa, Kenta*; Shimomura, Koichiro*; Otani, Masashi*; Kimura, Masato*; Kamioka, Shusei*; Yamazaki, Takayuki*; Mibe, Tsutomu*; et al.
Proceedings of 16th International Particle Accelerator Conference (IPAC25) (Internet), p.1163 - 1166, 2025/11
At the Japan Proton Accelerator Research Complex (J-PARC), low-emittance muon beams with a linear accelerator (linac) are proposed as a new approach to precisely measure the anomalous magnetic moment and electric dipole moment of the muon. Low-emittance muon beams can also be employed as new probes for non-destructive imaging techniques to see through structures. In the low-velocity section of the muon linac, a radio-frequency quadrupole linac (RFQ) and an interdigital H-mode drift tube linac (IH-DTL) are used to accelerate muons to
= v/c = 0.08 and 0.28, respectively, at an operating frequency of 324 MHz. To reduce construction costs, the IH-DTL employs the alternating phase focusing (APF) method, which uses the transverse focusing force derived from the RF electric field. Because the APF method limits the transverse and longitudinal acceptances simultaneously, careful beam diagnostics and commissioning are essential to suppress the emittance growth derived from beam mismatches. As a result of the beam simulation, by conducting appropriate beam matching, the normalized rms emittance of 0.3
-mm-mrad and the transmission to the downstream detector of 97% was obtained. In this paper, the results of the tracking simulation and the development status of the diagnostic and transport beamlines in the low-velocity section are described.
Nagai, Yuya; Kimura, Yasuhisa; Takeuchi, Kentaro; Shuji, Yoshiyuki; Kawasaki, Takeshi; Hirano, Koji*; Tomiyama, Noboru*; Usui, Yasuhiro*; Nidaira, Seiichiro*; Shinozaki, Tomohiro*; et al.
JAEA-Technology 2025-003, 110 Pages, 2025/10
Japan Atomic Energy Agency (JAEA) manages wide range of nuclear facilities. Many of these facilities are required to be performed adjustment with the aging and complement with the new regulatory standards and the earthquake resistant, since the Great East Japan Earthquake and the Fukushima Daiichi Nuclear Power Station accident. It is therefore desirable to promote decommissioning of facilities that have reached the end of their productive life in order to reduce risk and maintenance costs. However, the progress of facility decommissioning require large amount of money and radioactive waste storage space. In order to address these issues, JAEA has formulated a "The Medium/Long-Term Management Plan of JAEA Facilities" with three pillars: (1) consolidation and prioritization of facilities, (2) assurance of facility safety, and (3) back-end countermeasures. In this plan, Plutonium Fuel Fabrication Facility has been selected as primary decommissioned facility, and dismantling of equipment in the facilities have been underway. The following gloveboxes were dismantled between March 2020 and March 2022: Glovebox No. W-4, which houses the roasting furnace, washing and dewatering tank, and washing waste tank; Glovebox No. W-5, which houses the weighing tank; Glovebox No. W-6-1, which houses the flocculation-sedimentation tank, slurry-receiving tank, neutralization tank, and receiving tank; and Glovebox No. W-6-2, which houses the adjustment tank, adjustment liquid agitator, adsorption tower, discharge tank, discharge tank agitator, and adsorption tower. This report summarizes the results of the work and the findings obtained through the dismantling of these gloveboxes.
Nakamura, Satoshi; Ishii, Sho*; Kato, Hitoshi*; Ban, Yasutoshi; Hiruta, Kenta; Yoshida, Takuya; Uehara, Hiroyuki; Obata, Hiroki; Kimura, Yasuhiko; Takano, Masahide
Journal of Nuclear Science and Technology, 62(1), p.56 - 64, 2025/01
Times Cited Count:1 Percentile:25.34(Nuclear Science & Technology)A dissolution method for analyzing the elemental composition of fuel debris using the sodium peroxide (Na
O
) fusion technique has been developed. Herein, two different types of simulated debris materials (such as solid solution of (Zr,RE)O
and molten core-concrete interaction products (MCCI)) were taken. At various temperatures, these debris materials were subsequently fused with Na
O
in crucibles, which are made of different materials, such as Ni, Al
O
, Fe, and Zr. Then, the fused samples are dissolved in nitric acid. Furthermore, the effects of the experimental conditions on the elemental composition analysis were evaluated using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), which suggested the use of a Ni crucible at 923 K as an optimum testing condition. The optimum testing condition was then applied to the demonstration tests with Three Mile Island unit-2 (TMI-2) debris in a shielded concrete cell, thereby achieving complete dissolution of the debris. The elemental composition of TMI-2 debris revealed by the proposed dissolution method has good reproducibility and has an insignificant contradiction in the mass balance of the sample. Therefore, this newly developed reproducible dissolution method can be effectively utilized in practical applications by dissolving fuel debris and estimating its elemental composition.
Mo adsorption; Utilizing spray-dried mesoporous alumina for clinical-grade generator developmentAlowasheeir, A.*; Eguchi, Miharu*; Fujita, Yoshitaka; Tsuchiya, Kunihiko; Wakabayashi, Ryutaro*; Kimura, Tatsuo*; Ariga, Katsuhiko*; Hatano, Kentaro*; Fukumitsu, Nobuyoshi*; Yamauchi, Yusuke*
Bulletin of the Chemical Society of Japan, 97(10), p.uoae099_1 - uoae099_7, 2024/10
Times Cited Count:9 Percentile:71.05(Chemistry, Multidisciplinary)no abstracts in English

Yamamoto, Hajime*; Ikeda, Osamu*; Honda, Takashi*; Kimura, Kenta*; Aoyama, Takuya*; Ogushi, Kenya*; Suzuki, Akio*; Ishii, Kenji*; Matsumura, Daiju; Tsuji, Takuya; et al.
Physical Review Materials (Internet), 8(9), p.094402_1 - 094402_6, 2024/09
Times Cited Count:4 Percentile:32.24(Materials Science, Multidisciplinary)
Ba
(PO
)
(
= Mg, Mn, Co, and Ni)Kajita, Yoichi*; Nagai, Takayuki*; Yamagishi, Shigetada*; Kimura, Kenta*; Hagihara, Masato; Kimura, Tsuyoshi*
Chemistry of Materials, 36(15), p.7451 - 7458, 2024/08
Times Cited Count:9 Percentile:71.21(Chemistry, Physical)Iwata, Takuma*; Kosa, Towa*; Nishioka, Yukimi*; Owada, Kiyotaka*; Sumida, Kazuki; Annese, E.*; Kakoki, Masaaki*; Kuroda, Kenta*; Iwasawa, Hideaki*; Arita, Masashi*; et al.
Scientific Reports (Internet), 14, p.127_1 - 127_8, 2024/01
Times Cited Count:12 Percentile:84.43(Multidisciplinary Sciences)Yamagishi, Shigetada*; Hayashida, Takeshi*; Misawa, Ryusuke*; Kimura, Kenta*; Hagihara, Masato; Murata, Tomoki*; Hirose, Sakyo*; Kimura, Tsuyoshi*
Chemistry of Materials, 35(2), p.747 - 754, 2023/01
Times Cited Count:18 Percentile:76.06(Chemistry, Physical)Hayashida, Takeshi*; Uemura, Yohei*; Kimura, Kenta*; Matsuoka, Satoshi*; Hagihara, Masato; Hirose, Sakyo*; Morioka, Hitoshi*; Hasegawa, Tatsuo*; Kimura, Tsuyoshi*
Physical Review Materials (Internet), 5(12), p.124409_1 - 124409_10, 2021/12
Times Cited Count:45 Percentile:86.27(Materials Science, Multidisciplinary)
Ta
O
Kimura, Kenta*; Yagi, Naoki*; Hasegawa, Shunsuke*; Hagihara, Masato; Miyake, Atsushi*; Tokunaga, Masashi*; Cao, H.*; Masuda, Takatsugu*; Kimura, Tsuyoshi*
Inorganic Chemistry, 60(20), p.15078 - 15084, 2021/10
Times Cited Count:6 Percentile:37.97(Chemistry, Inorganic & Nuclear)
Te
Shikin, A. M.*; Estyunin, D. A.*; Klimovskikh, I. I.*; Filnov, S. O.*; Kumar, S.*; Schwier, E. F.*; Miyamoto, Koji*; Okuda, Taichi*; Kimura, Akio*; Kuroda, Kenta*; et al.
Scientific Reports (Internet), 10, p.13226_1 - 13226_13, 2020/08
Times Cited Count:84 Percentile:95.53(Multidisciplinary Sciences)Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.
Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12
The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.
Am at neutron energies below fission thresholdHirose, Kentaro; Nishio, Katsuhisa; Makii, Hiroyuki; Nishinaka, Ichiro*; Ota, Shuya*; Nagayama, Tatsuro*; Tamura, Nobuyuki*; Goto, Shinichi*; Andreyev, A. N.; Vermeulen, M. J.; et al.
Nuclear Instruments and Methods in Physics Research A, 856, p.133 - 138, 2017/06
Times Cited Count:5 Percentile:37.05(Instruments & Instrumentation)
Nd and stellar neutron capture cross sectionsKatabuchi, Tatsuya*; Matsuhashi, Taihei*; Terada, Kazushi; Igashira, Masayuki*; Mizumoto, Motoharu*; Hirose, Kentaro; Kimura, Atsushi; Iwamoto, Nobuyuki; Hara, Kaoru*; Harada, Hideo; et al.
Physical Review C, 91(3), p.037603_1 - 037603_5, 2015/03
Times Cited Count:8 Percentile:46.53(Physics, Nuclear)
) reactions with the ANNRI-Cluster Ge detectors at J-PARCHara, Kaoru; Goko, Shinji*; Harada, Hideo; Hirose, Kentaro; Kimura, Atsushi; Kin, Tadahiro*; Kitatani, Fumito; Koizumi, Mitsuo; Nakamura, Shoji; Toh, Yosuke; et al.
JAEA-Conf 2014-002, p.88 - 92, 2015/02
under various selections of temperature conditionsYamamoto, Masato*; Kimura, Akihiko*; Onizawa, Kunio; Yoshimoto, Kentaro*; Ogawa, Takuya*; Mabuchi, Yasuhiro*; Viehrig, H.-W.*; Miura, Naoki*; Soneda, Naoki*
Proceedings of 2014 ASME Pressure Vessels and Piping Conference (PVP 2014) (DVD-ROM), 7 Pages, 2014/07
The Master Curve (MC) approach for the fracture toughness reference temperature To is expected to be a powerful tool to ensure the reliability of long-term used RPV steels. In order to get sufficient number of data for the MC approach related to the present surveillance program for RPVs, the use of miniature specimens is important. The test technique for the miniature specimens (Mini-CT) of 4 mm thick had been verified the basic applicability of MC approach by means of Mini-CT for the determination of fracture toughness of typical Japanese RPV steels. A round robin (RR) program was organized to assure the robustness of the technique. As the third step of RR program, blinded tests were carried out. Precise material information was not provided to the participants. From the results obtained, the scatter range in
was within the acceptable scatter range specified in the testing standard. The selection of testing temperature seems to give limited effect like that in larger specimens.
Sn and
Sn with J-PARC/MLF/ANNRIKimura, Atsushi; Hirose, Kentaro; Nakamura, Shoji; Harada, Hideo; Hara, Kaoru; Hori, Junichi*; Igashira, Masayuki*; Kamiyama, Takashi*; Katabuchi, Tatsuya*; Kino, Koichi*; et al.
Nuclear Data Sheets, 119, p.150 - 153, 2014/05
Times Cited Count:5 Percentile:35.54(Physics, Nuclear)
Am(n,
) at J-PARC/MLF/ANNRIHarada, Hideo; Ota, Masayuki; Kimura, Atsushi; Furutaka, Kazuyoshi; Hirose, Kentaro; Hara, Kaoru; Kin, Tadahiro*; Kitatani, Fumito; Koizumi, Mitsuo; Nakamura, Shoji; et al.
Nuclear Data Sheets, 119, p.61 - 64, 2014/05
Times Cited Count:19 Percentile:72.85(Physics, Nuclear)
Pd and stable
Pd nuclei at J-PARC/MLF/ANNRINakamura, Shoji; Kimura, Atsushi; Kitatani, Fumito; Ota, Masayuki; Furutaka, Kazuyoshi; Goko, Shinji*; Hara, Kaoru; Harada, Hideo; Hirose, Kentaro; Kin, Tadahiro*; et al.
Nuclear Data Sheets, 119, p.143 - 146, 2014/05
Times Cited Count:10 Percentile:53.97(Physics, Nuclear)We have started the measurements of the neutron-capture cross sections for stable
Pd nuclei as well as the radioactive
Pd. The neutron-capture cross-section measurements by the time-of flight method were performed using an apparatus called "Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI)" installed at the neutron Beam Line No.4 of the Materials and Life science experimental Facility (MLF) in the J-PARC. The neutron-capture cross sections of
Pd and
Pd have been measured in the neutron energy range from thermal to 300 eV. Some new information was obtained for resonances of these Pd nuclei.
rays from the neutron resonances of
Se and
Se at the J-PARC/MLF/ANNRIHori, Junichi*; Yashima, Hiroshi*; Nakamura, Shoji; Furutaka, Kazuyoshi; Hara, Kaoru; Harada, Hideo; Hirose, Kentaro; Kimura, Atsushi; Kitatani, Fumito; Koizumi, Mitsuo; et al.
Nuclear Data Sheets, 119, p.128 - 131, 2014/05
Times Cited Count:4 Percentile:30.33(Physics, Nuclear)In this work, we measured the capture
rays from the neutron resonances of
Se and
Se. A neutron time-of-flight method was adopted for the measurements with a 4
Ge spectrometer installed at the Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) in the J-PARC Material and Life science experimental Facility (MLF). The
-ray pulse-height spectra corresponding to the 27-eV resonance of
Se and the 113-, 212-, 291-, 342-, 690- and 864-eV resonances of
Se were obtained by gating on the TOF regions, respectively. The relative intensities of those primary transitions were derived and compared with the previous experimental data. For the 27-eV resonance of
Se, a strong primary transition to the 293-keV state was observed. As for
Se, the quite differences of the decay pattern were found between the resonances.