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Tamura, Jun; Kondo, Yasuhiro; Yee-Rendon, B.; Meigo, Shinichiro; Maekawa, Fujio; Kako, Eiji*; Umemori, Kensei*; Sakai, Hiroshi*; Domae, Takeshi*
Proceedings of 22nd International Conference on RF Superconductivity (SRF2025), p.691 - 694, 2026/04
Japan Atomic Energy Agency (JAEA) has been proposing an accelerator-driven nuclear transmutation system (ADS) as a future nuclear system to efficiently reduce high-level radioactive waste generated in nuclear power plants. As the first step toward the full-scale CW proton linac for the JAEA-ADS, we are currently prototyping a low-beta (around 0.2) single-spoke cavity. Since there is no experience in manufacturing superconducting spoke cavities in Japan, prototyping and performance evaluation of the cavity are essential to ensure the feasibility of the JAEA-ADS. The actual cavity fabrication started in 2020, and the cavity assembly by electron beam welding was finally completed in fiscal year 2024. In this assembly, the target resonance frequency of 324 MHz was achieved by trimming the ends of the cavity parts several times before the final welding. In the final welding, smooth weld beads were obtained by combining circular-correction and end-thinning for the cavity parts to be welded. The fabrication of the prototype spoke cavity is presented.
Tamura, Jun; Kondo, Yasuhiro; Yee-Rendon, B.; Meigo, Shinichiro; Maekawa, Fujio; Kako, Eiji*; Umemori, Kensei*; Sakai, Hiroshi*; Domae, Takeshi*
Proceedings of 32nd Linear Accelerator Conference (LINAC 2024) (Internet), p.496 - 498, 2024/10
C
reaction at 1.8 GeV/
with the Superconducting Kaon spectrometerIchikawa, Yudai; Fujita, Manami; Hasegawa, Shoichi; Imai, Kenichi*; Nanamura, Takuya; Naruki, Megumi; Sato, Susumu; Sako, Hiroyuki; Tamura, Hirokazu; Tanida, Kiyoshi; et al.
Progress of Theoretical and Experimental Physics (Internet), 2024(9), p.091D01_1 - 091D01_13, 2024/09
Times Cited Count:3 Percentile:52.96(Physics, Multidisciplinary)Yoshimoto, Masataka*; Tamura, Kazuhisa; Watanabe, Kenta*; Shimizu, Keisuke*; Horisawa, Yuhei*; Kobayashi, Takeshi*; Tsurita, Hanae*; Suzuki, Kota*; Kanno, Ryoji*; Hirayama, Masaaki*
Sustainable Energy & Fuels (Internet), 8(6), p.1236 - 1244, 2024/03
Times Cited Count:2 Percentile:21.31(Chemistry, Physical)Photo-rechargeable systems, which can efficiently convert and store solar energy into chemical energy within single devices, are essential to harness sunlight effectively. Photo-(de)intercalation plays a pivotal role in the functionality of photorechargeable systems. Nevertheless, the photo-(de)intercalation process has not been conclusively confirmed owing to potential interference from side reactions, such as the decomposition of liquid electrolytes and the elution of electrode materials. In this study, we successfully demonstrated photo-responsive Li
-deintercalation using an all-solid-state thin-film battery comprised of epitaxially-grown anatase TiO
doped with Nb (a-TiO
:Nb) as the cathode. Under light irradiation, Li
-deintercalation occurred and was subsequently reversibly intercalated into a-TiO
:Nb during discharge.
Tamura, Jun; Kondo, Yasuhiro; Yee-Rendon, B.; Meigo, Shinichiro; Maekawa, Fujio; Kako, Eiji*; Umemori, Kensei*; Sakai, Hiroshi*; Domae, Takeshi*
Journal of Physics; Conference Series, 2687(5), p.052008_1 - 052008_6, 2024/01
Times Cited Count:0 Percentile:0.00(Physics, Atomic, Molecular & Chemical)Koyama, Shinichi; Ikeuchi, Hirotomo; Mitsugi, Takeshi; Maeda, Koji; Sasaki, Shinji; Onishi, Takashi; Tsai, T.-H.; Takano, Masahide; Fukaya, Hiroyuki; Nakamura, Satoshi; et al.
Hairo, Osensui, Shorisui Taisaku Jigyo Jimukyoku Homu Peji (Internet), 216 Pages, 2023/11
In FY 2021 and 2022, JAEA perfomed the subsidy program for "the Project of Decommissioning and Contaminated Water Management (Development of Analysis and Estimation Technology for Characterization of Fuel Debris (Development of Technologies for Enhanced Analysis Accuracy, Thermal Behavior Estimation, and Abbreviated Analysis))" started in FY 2021. This presentation material summarized the results of the project, which will be available shortly on the website of Management Office for the Project of Decommissioning, Contaminated Water and Treated Water Management.
Kondo, Yasuhiro; Tamura, Jun; Yee-Rendon, B.; Meigo, Shinichiro; Maekawa, Fujio; Kako, Eiji*; Umemori, Kensei*; Sakai, Hiroshi*; Domae, Takeshi*
Proceedings of 21st International Conference on Radio-Frequency Superconductivity (SRF 2023), p.947 - 951, 2023/07
Japan Atomic Energy Agency (JAEA) has been proposing an accelerator-driven system (ADS) as a future nuclear system to efficiently reduce the high-level radioactive waste generated at nuclear power plants. As the first step toward the full-scale CW proton linac for the JAEA-ADS, we are now prototyping a low-beta (around 0.2) single-spoke cavity. Because there is no experience in manufacturing super-conducting spoke cavities in Japan, prototyping and performance testing of the cavity are essential to ensure the feasibility of the JAEA-ADS. The dimensional parameters of the prototype spoke cavity were optimized to obtain higher cavity performance. The actual cavity fabrication started in 2020. Most of the cavity parts were fabricated in fiscal year 2020 by press-forming and machining. In 2021, we started welding the cavity parts together. After investigating the optimum welding conditions using mock-up test pieces, each cavity part was joined with smooth welding beads. Currently, the cavity's body section and the beam port sections have been assembled. This paper presents the current status of the JAEA-ADS and it's cavity prototyping.
Tamura, Fumihiko; Omori, Chihiro*; Yoshii, Masahito*; Tomizawa, Masahito*; Toyama, Takeshi*; Sugiyama, Yasuyuki*; Hasegawa, Katsushi*; Kobayashi, Aine*; Okita, Hidefumi
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.175 - 178, 2023/01
J-PARC MR delivers high intensity proton beams to the neutrino experiment. Eight bunches with high peak currents are extracted from the MR by the extraction kicker, therefore the neutrino beam has the similar structure. Intermediate Water Cherenkov Detector (IWCD) will be installed for the future experiments and the IWCD requires a time structure with low peaks. We consider bunch manipulation at flattop of the MR for reducing the peak current. It should be quickly done to avoid the significant loss of the beam power. The beam gap for the kicker rise time must be kept. We propose a non-adiabatic bunch manipulation using the multiharmonic rf voltage. The longitudinal impedance in the MR can affect the beam stability. The feasibility of the manipulation is discussed by using the longitudinal simulations.
atomic X-ray spectroscopy using a counter-emulsion hybrid methodFujita, Manami; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Masaya; Ichikawa, Yudai; Kim, S.; Nanamura, Takuya; Sako, Hiroyuki; Tamura, Hirokazu; Yamamoto, Takeshi; et al.
Progress of Theoretical and Experimental Physics (Internet), 2022(12), p.123D01_1 - 123D01_17, 2022/12
Times Cited Count:1 Percentile:12.63(Physics, Multidisciplinary)
atoms (J-PARC E03, E07 and future)Yamamoto, Takeshi; Fujita, Manami; Gogami, Toshiyuki*; Harada, Takeshi*; Hayakawa, Shuhei*; Hosomi, Kenji; Ichikawa, Yudai; Ishikawa, Yuji*; Kamata, K.*; Kanauchi, H.*; et al.
EPJ Web of Conferences, 271, p.03001_1 - 03001_5, 2022/11
Sakuma, Fuminori*; Tamura, Hirokazu; Tanida, Kiyoshi; Yamamoto, Takeshi; 39 of others*
EPJ Web of Conferences, 271, p.11001_1 - 11001_7, 2022/11
Miwa, Koji*; Fujita, Manami; Harada, Takeshi; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Masaya; Imai, Kenichi*; Sako, Hiroyuki; Sato, Susumu; Tamura, Hirokazu; et al.
EPJ Web of Conferences, 271, p.04001_1 - 04001_7, 2022/11
Gogami, Toshiyuki*; Ebata, Kengo; Fujita, Manami; Harada, Takeshi; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi*; Kim, S.; Nanamura, Takuya; et al.
EPJ Web of Conferences, 271, p.11002_1 - 11002_7, 2022/11
atomic X-raysFujita, Manami; Hosomi, Kenji; Ishikawa, Yuji*; Kanauchi, H.*; Koike, Takeshi*; Ogura, Yu*; Tamura, Hirokazu; Tanida, Kiyoshi; Ukai, Mifuyu*; Yamamoto, Takeshi
Nuclear Instruments and Methods in Physics Research A, 1042, p.167439_1 - 167439_9, 2022/11
Times Cited Count:3 Percentile:36.07(Instruments & Instrumentation)Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.
Journal of Nuclear Science and Technology, 59(9), p.1174 - 1205, 2022/09
Times Cited Count:10 Percentile:72.91(Nuclear Science & Technology)In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.
Tamura, Jun; Kondo, Yasuhiro; Yee-Rendon, B.; Meigo, Shinichiro; Maekawa, Fujio; Kako, Eiji*; Umemori, Kensei*; Sakai, Hiroshi*; Domae, Takeshi*
Proceedings of 31st International Linear Accelerator Conference (LINAC 2022) (Internet), p.180 - 183, 2022/09
The Japan Atomic Energy Agency (JAEA) has proposed an accelerator-driven subcritical system (ADS) to efficiently reduce high-level radioactive waste generated at nuclear power plants. One of the challenging R&D aspects of ADS is the reliability of the accelerator. In preparation for the full-scale design of the CW proton linac for the JAEA-ADS, we are now prototyping a low-beta (around 0.2) single spoke cavity. Since there is no experience in Japan in manufacturing a superconducting spoke cavity, prototyping and performance testing of the cavity is essential to ensure the feasibility of the JAEA-ADS linac. In the Japanese fiscal year 2021, we have started welding cavity parts together. By preliminarily examining the electron beam welding conditions, each press-formed niobium part was joined with a smooth welding bead. At present, we have fabricated the cavity's body part.
elastic scattering in the momentum range 0.44-0.80 GeV/cNanamura, Takuya; Fujita, Manami; Hasegawa, Shoichi; Ichikawa, Masaya; Ichikawa, Yudai; Imai, Kenichi*; Naruki, Megumi; Sato, Susumu; Sako, Hiroyuki; Tamura, Hirokazu; et al.
Progress of Theoretical and Experimental Physics (Internet), 2022(9), p.093D01_1 - 093D01_35, 2022/09
Times Cited Count:20 Percentile:82.68(Physics, Multidisciplinary)
reaction in momentum range 470-650 MeV/
Miwa, Koji*; Fujita, Manami; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Yudai*; Imai, Kenichi*; Nanamura, Takuya; Sako, Hiroyuki; Sato, Susumu; Tamura, Hirokazu; et al.
Physical Review Letters, 128(7), p.072501_1 - 072501_6, 2022/02
Times Cited Count:24 Percentile:87.20(Physics, Multidisciplinary)
elastic scattering in momentum range 470 to 850 MeV/
Miwa, Koji*; Fujita, Manami; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi*; Nanamura, Takuya; Naruki, Megumi; Sako, Hiroyuki; Sato, Susumu; et al.
Physical Review C, 104(4), p.045204_1 - 045204_20, 2021/10
Times Cited Count:24 Percentile:90.25(Physics, Nuclear)Kondo, Yasuhiro; Harada, Hiroyuki; Kabumoto, Hiroshi; Kamiya, Junichiro; Matsuda, Makoto; Moriya, Katsuhiro; Tamura, Jun; Kako, Eiji*; Domae, Takeshi*; Sakai, Hiroshi*; et al.
Proceedings of 20th International Conference on RF Superconductivity (SRF 2021) (Internet), p.299 - 302, 2021/10
The Japan Atomic Energy Agency (JAEA) tandem booster is one of the pioneering superconducting heavy ion linac in the world. It consists of 40 QWRs with an operation frequency of 130 MHz and
, and has potential to accelerate various ions up to Au to 10 MeV/u. The user operation was started in 1994, however, it has been suspended since the Great East Japan Earthquake in 2011. Recently, in addition to the efforts to restart the tandem booster, activities to develop new lower-beta cavities to improve the acceleration efficiency of heavier ions such as Uranium has been launched. In this work, the current status of the design study of the QWRS for the JAEA tandem facility is presented. Electro-magnetic design using simulation code was performed and acceleration gradient of 5.7 MV/m and 6.6 MV/m was obtained for 130-MHz and 65-MHz QWRs, respectively.