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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：5 Percentile：81.82(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.
Yamamoto, Kazami; Hasegawa, Kazuo; Kinsho, Michikazu; Oguri, Hidetomo; Hayashi, Naoki; Yamazaki, Yoshio; Naito, Fujio*; Yoshii, Masahito*; Toyama, Takeshi*
JPS Conference Proceedings (Internet), 33, p.011016_1 - 011016_7, 2021/03
The Japan Proton Accelerator Research Complex (J-PARC) is a multipurpose facility for scientific experiments. The accelerator complex consists of a 400-MeV Linac, a 3-GeV Rapid-Cycling Synchrotron (RCS) and a 30-GeV Main Ring synchrotron (MR). The RCS delivers a proton beam to the neutron target and MR, and the MR delivers the beams to the neutrino target and the Hadron Experimental Facility. The first operation of the neutron experiments began in December 2008. Following this, the user operation has been continued with some accidental suspensions. These suspensions include the recovery work due to the Great East Japan Earthquake in March 2011 and the radiation leak incident at the Hadron Experimental Facility. In this report, we summarize the major causes of suspension, and the statistics of the reliability of J-PARC accelerator system is analyzed. Owing to our efforts to achieve higher reliability, the Mean Time Between Failure (MTBF) has been improved.
Hasegawa, Kazuo; Kinsho, Michikazu; Oguri, Hidetomo; Yamamoto, Kazami; Hayashi, Naoki; Yamazaki, Yoshio; Naito, Fujio*; Yoshii, Masahito*; Toyama, Takeshi*; Yamamoto, Noboru*; et al.
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1235 - 1239, 2019/07
After the summer shutdown in 2018, the J-PARC restarted user operation in late October. While beam power to the Materials and Life Science Experimental Facility (MLF) was 500 kW as before the summer shutdown, linac beam current was increased from 40 to 50 mA. Operation of the Main Ring (MR) was suspended due to the modification and/or maintenance of the Superkamiokande (neutrino detector) and Hadron experimental facility. The user operation was resumed in the middle of February for the Hadron experimental facility at 51 kW. But on March 18, one of the bending magnets in the beam transport line to the MR had a failure. It was temporary recovered and restored beam operation on April 5, but the failure occurred again on April 24 and the beam operation of the MR was suspended. In the fiscal year of 2018, the availabilities for the MLF, neutrino and hadron facilities are 94%, 86%, and 74%, respectively.
Hasegawa, Kazuo; Kinsho, Michikazu; Oguri, Hidetomo; Yamamoto, Kazami; Hayashi, Naoki; Yamazaki, Yoshio; Naito, Fujio*; Yoshii, Masahito*; Yamamoto, Noboru*; Koseki, Tadashi*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1317 - 1321, 2018/08
After the summer shutdown in 2017, the J-PARC restarted user operation in late October. The Materials and Life Science Experimental Facility (MLF) used a spare target and the beam power was limited to 150-200kW. The target was replaced with a new one in the summer shutdown. The beam power was for user operation gradually increased from 300 kW to 500 kW. We have successfully demonstrated 1MW 1hour operation in July 2018. The beam power for the neutrino experimental facility (NU) was 440 kW to 470 kW. The beam was delivered to the hadron experimental facility (HD) from January to February in 2018. The repetition rate of the main ring was shortened from 5.52 to 5.20 seconds, the beam power was increased from 44 to 50 kW. From March 2018, we delivered to the NU at 490 kW stably. In the fiscal year of 2017, the availabilities for the MLF, NU and HD are 93%, 89% and 66%, respectively.
Hasegawa, Kazuo; Hayashi, Naoki; Oguri, Hidetomo; Yamamoto, Kazami; Kinsho, Michikazu; Yamazaki, Yoshio; Naito, Fujio; Koseki, Tadashi; Yamamoto, Noboru; Yoshii, Masahito
Proceedings of 9th International Particle Accelerator Conference (IPAC '18) (Internet), p.1038 - 1040, 2018/06
Hasegawa, Kazuo; Kinsho, Michikazu; Oguri, Hidetomo; Yamamoto, Kazami; Hayashi, Naoki; Yamazaki, Yoshio; Naito, Fujio*; Hori, Yoichiro*; Yamamoto, Noboru*; Koseki, Tadashi*
Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1317 - 1321, 2017/12
After the summer shutdown in 2016, the J-PARC restarted user operation late in October for the neutrino experiments (NU) and early in November for the materials and life science experimental facility (MLF). The beam power for the NU was 420 kW in May 2016, but increased to 470 kW in February 2017 thanks to the change and optimization of operation parameters. For the hadron experimental facility (HD), we started beam tuning in April, but suspended by a failure of the electro static septum. After the treatment, we delivered beam at the power of 37 kW. We delivered beam at 150kW for the MLF. In the fiscal year of 2016, the linac, the 3 GeV synchrotron (RCS) and the MLF were stable and the availability was high at 93%. On the contrary, the main ring has several failures and the availabilities were 77% and 84% for NU and HD, respectively.
Hasegawa, Kazuo; Hayashi, Naoki; Oguri, Hidetomo; Yamamoto, Kazami; Kinsho, Michikazu; Yamazaki, Yoshio; Naito, Fujio*; Koseki, Tadashi*; Yamamoto, Noboru*; Hori, Yoichiro*
Proceedings of 8th International Particle Accelerator Conference (IPAC '17) (Internet), p.2290 - 2293, 2017/06
The J-PARC is a high intensity proton facility and the accelerator consists of a 400 MeV linac, a 3 GeV Rapid Cycling Synchrotron (RCS) and a 30 GeV Main Ring Synchrotron (MR). We have taken many hardware upgrades such as front end replacement and energy upgrade at the linac, vacuum improvement, collimator upgrade, etc. The beam powers for the neutrino experiment and hadron experiment from the MR have been steadily increased by tuning and reducing beam losses. The designed 1 MW equivalent beam was demonstrated and user program was performed at 500 kW from the RCS to the neutron and muon experiments. We have experienced many failures and troubles, however, to impede full potential and high availability. In this report, operational performance and status of the J-PARC accelerators are presented.
Mo manufacturing process, 1; Reusability evaluation of Mo absorbent (Joint research)Kimura, Akihiro; Niizeki, Tomotake*; Kakei, Sadanori*; Chakrova, Y.*; Nishikata, Kaori; Hasegawa, Yoshio*; Yoshinaga, Hideo*; Chakrov, P.*; Tsuchiya, Kunihiko
JAEA-Technology 2013-025, 40 Pages, 2013/10
JAEA-Technology-2013-025.pdf:2.62MB
Neutron Irradiation and Testing Reactor Center has developed the production of a medical isotope of Mo, the parent nuclide of 
Tc by the (n,
) method using JMTR. The (n,) method has an advantage of easy manufacturing process and low radioactive wastes generation. However, the low radioactivity concentration of Tc is remaining as an issue. Therefore, PZC and PTC have been developed as adsorbent of molybdenum. Meanwhile, it is necessary to recycle the absorbent and Mo for the reduction of the radioactive waste of used-adsorbent and the effective use of limited resources, respectively. This report summarizes results of the synthesis of Mo adsorbents such as PZC and PTC, and the performance tests.
Kakei, Sadanori*; Kimura, Akihiro; Niizeki, Tomotake*; Ishida, Takuya; Nishikata, Kaori; Kurosawa, Makoto; Yoshinaga, Hideo*; Hasegawa, Yoshio*; Tsuchiya, Kunihiko
Proceedings of 6th International Symposium on Material Testing Reactors (ISMTR-6) (Internet), 7 Pages, 2013/10
The Japan Materials Testing Reactor (JMTR) is expected to contribute to the expansion of industrial utilization, such as the domestic production of Mo for the medical diagnosis medicine 
Tc. Production by the (n, ) method is proposed as domestic Mo production in JMTR because of the low amount of radioactive wastes and the easy Mo/Tc production process. Molybdenum oxide (MoO
) pellets, poly zirconium compounds (PZC) and poly titanium compounds (PTC) are used as the irradiation target and generator for the production of Mo/Tc by the (n, ) method. However, it is necessary to use the enriched 
MoO, which is very expensive, to increase the specific activity of Mo. Additionally, a large amount of used PZC and PTC is generated after the decay of Mo. Therefore, this recycling technology of used PZC/PTC has been developed to recover molybdenum (Mo) as an effective use of resources and a reduction of radioactive wastes. The total Mo recovery rate of this process was 95.8%. From the results of the hot experiments, we could demonstrate that the recovery of MoO and the recycling of PZC are possible. In the future, the equipment of recovering Mo will be installed in JMTR-Hot Cell, and this recycling process will be able to contribute to the reduction of production costs of Tc and the reduction of radioactive wastes.
Mo-Tc domestic production with high-density MoO pellets by (n,) reactionTsuchiya, Kunihiko; Tanase, Masakazu*; Takeuchi, Nobuhiro*; Kobayashi, Masaaki*; Hasegawa, Yoshio*; Yoshinaga, Hideo*; Kaminaga, Masanori; Ishihara, Masahiro; Kawamura, Hiroshi
Proceedings of 5th International Symposium on Material Testing Reactors (ISMTR-5) (Internet), 10 Pages, 2012/10
As one of effective uses of the JMTR, JAEA has a plan to produce Mo by (n, ) method, a parent nuclide of Tc. In case of Japan, the supplying of Mo depends only on imports from foreign countries. The R&D on production method of Mo -Tc has been performed with Japanese industrial users under the cooperation programs. The main R&D items for the production are (1) Fabrication of irradiation target such as the sintered MoO pellets, (2) Separation and concentration of Tc by the solvent extraction from Mo solution, (3) Examination of Tc solution for a medicine, and (4) Mo recycling from Mo generator and solution. In this paper, the status of the R&D is introduced for the production of Mo -Tc.
Taguchi, Tomitsugu; Hasegawa, Yoshio*; Shamoto, Shinichi
Journal of Nuclear Materials, 417(1-3), p.348 - 352, 2011/10
The SiC/SiC composites with and without dispersed carbon nanofiber were fabricated by polymer impregnation and pyrolysis process. The effect of dispersing with 6 vol.% carbon nanofiber on the mechanical and thermal properties of SiC/SiC composites was investigated. The bending strength and elastic modulus of SiC/SiC composites with carbon nanofiber decreased slightly compared to those of the SiC/SiC composites without carbon nanofiber. On the other hand, the thermal conductivity of SiC/SiC composites increased with increasing the amount of dispersed carbon nanofiber. The dominant reason is considered that the pore shape changed from oblong shape vertical to direction of heat flow to isotropic shape by dispersing carbon nanofiber.
Kimura, Akihiro; Tanimoto, Masataka; Ishida, Takuya; Tsuchiya, Kunihiko; Hasegawa, Yoshio*; Hishinuma, Yukio*; Suzuki, Masashi*
JAEA-Technology 2011-012, 17 Pages, 2011/06
JAEA-Technology-2011-012.pdf:1.72MBJP, 2010-263801 Patent publication (In Japanese)
PZC (Poly-Zirconium Compound) was developed as adsorbent of molybdenum for Mo-Tc generator. However, PZC has some faults. So, new adsorbent based on titanium (PTC), was developed for getting rid of faults. This time, Mo adsorption and Tc elution tests with PZC and PTC were carried out. As a result, the Mo adsorption performance of the PTC was lower than PZC, on the other hand, Tc elution performance of the PTC was higher than PZC.
fiber under visible light illumination (Joint research)Takeyama, Akinori; Yamamoto, Shunya; Yoshikawa, Masahito; Hasegawa, Yoshio*; Awatsu, Satoshi*
JAEA-Research 2007-012, 29 Pages, 2007/03
JAEA-Research-2007-012.pdf:3.77MB
The Sol-Gel derived precursor fiber was annealed under hydrogen disulfeid (HS) following oxygen atmosphere, Sulfer-doped titanium dioxide (TiO) fiber was obtained. Crystal structure of the fiber was identified as anatase phase of TiO. The energy band gap of the fiber was narrower by about 0.06 eV than that of anatase, which showed that it could absorb visible light. The fiber contains about 0.58 atomic % of Sulfer, and they located at the oxygen lattice site of TiO. Under visible light illumination, the fiber degraded Trichroloethylen (TCE) and produced carbon dioxide (CO). This shows Sulfer-doped TiO fiber has the photocatalytic activity under visible light illumination.
; Miyamoto, Shuji*; ; ; ; Hasegawa, Makoto; Yamazaki, Yoshio
JNC TY9400 2000-008, 20 Pages, 2000/03
JNC-TY9400-2000-008.pdf:0.81MB
no abstracts in English
Hirano, Koichiro; ; Yamazaki, Yoshio; Nomura, Masahiro; ; Hasegawa, Makoto
Proceedings of 7th European Particle Accelerator Conference (EPAC 2000), 0 Pages, 2000/00
None
Kawamura, Hiroshi; ; ; ; R.R.Solomon*;
Fusion Technology 1996, 0, p.1499 - 1502, 1997/00
no abstracts in English
Tc generator using a new adsorbentTanase, Masakazu; ;
Isotope News, 0(509), p.6 - 9, 1996/10
no abstracts in English
; ; ; ; ; Tanase, Masakazu; Kurosawa, Kiyoyuki
Nihon Kagakkai-Shi, 0(10), p.888 - 894, 1996/00
no abstracts in English
木村 明博; 谷本 政隆; 石田 卓也; 土谷 邦彦
長谷川 良雄*; 菱沼 行男*; 栗原 克宜*; 鈴木 将*
JP, 2010-263801 Patent licensing information Patent publication (In Japanese)
【課題】塩素を含むPZCに代わる、塩素フリーの無機高分子系吸着剤及びその製造方法を提供すること。 【解決手段】以下の化学式(A)、(B)及び(C)を含み、これらの繰り返し単位から成る骨格構造を有し、Mが4価の金属、例えばチタンであり、Xが例えば1個から6個までの炭素原子を有するアルコキシ基又は有機配位子のいずれかである99Mo-99mTcジェネレータ用の無機高分子系モリブデン吸着剤。
谷本 政隆; 木村 明博; 西方 香緒里; 土谷 邦彦
長谷川 良雄*; 菱沼 行男*; 新関 智丈*; 鈴木 将*; 永山 紗智子*; 吉永 英雄*; 掛井 貞紀*
JP, 2012-081241 Patent licensing information Patent publication (In Japanese)
【課題】モリブデンの効率的な回収を低コストで行うためのモリブデンのサイクルシステム及び該サイクルシステムに使用されるモリブデン吸着剤の再生方法を提供する。 【解決手段】本発明は、モリブデン99を含有するモリブデン又は三酸化モリブデンを溶解してモリブデン吸着剤に吸着する工程、前記のモリブデン吸着剤から成るジェネレータからテクネチウム99Mを抽出した後の使用済みモリブデン吸着剤に存在するモリブデンを脱着する工程、前記モリブデン脱着後のモリブデン吸着剤にモリブデン99含有のモリブデンを再吸着する工程、及び前記の脱着工程によって回収される三酸化モリブデンを再利用する工程を含むモリブデンのサイクルシステムであり、前記の再吸着工程で使用されるモリブデン脱着後の再生モリブデン吸着剤は、水中等で保存され、繰返し単位の構造中にOH基を少なくとも1つ有することを特徴とする。
