Fujimoto, Nozomu*; Fukuda, Kodai*; Honda, Yuki*; Tochio, Daisuke; Ho, H. Q.; Nagasumi, Satoru; Ishii, Toshiaki; Hamamoto, Shimpei; Nakano, Yumi*; Ishitsuka, Etsuo
JAEA-Technology 2021-008, 23 Pages, 2021/06
The effect of mesh division around the burnable poison rod on the burnup calculation of the HTTR core was investigated using the SRAC code system. As a result, the mesh division inside the burnable poison rod does not have a large effect on the burnup calculation, and the effective multiplication factor is closer to the measured value than the conventional calculation by dividing the graphite region around the burnable poison rod into a mesh. It became clear that the mesh division of the graphite region around the burnable poison rod is important for more appropriately evaluating the burnup behavior of the HTTR core..
Oi, Motoki; Meigo, Shinichiro; Akutsu, Atsushi*; Kawasaki, Tomoyuki; Nishikawa, Masaaki*; Fukuda, Shimpei
Proceedings of 12th International Topical Meeting on Nuclear Applications of Accelerators (AccApp '15), p.89 - 96, 2016/00
At J-PARC, 3 GeV proton beam with power of 1MW is delivered to the spallation neutron source (JSNS) through beam transport line called 3NBT. At the high power accelerator facilities even a small abnormal event has a possibility to be critical so that the beam control system is crucial. In order to find tiny anomaly, rapid data analysis system is required. We developed control and data analysis system based on the Experimental Physics and Industrial Control System (EPICS) and Control System Studio (CSS). To carry out beam tuning efficiently, the beam control system based on the Strategic Accelerator Design (SAD) code has been developed. With the several shots of beam and by the one click of operational panel of the screen, required magnet field can be calculated and set automatically. Also we developed automated e-mail system to announce the abnormal event to the experts persons. With these systems, we can reduce both beam tuning time and down time.
Meigo, Shinichiro; Oi, Motoki; Ikezaki, Kiyomi*; Kawasaki, Tomoyuki; Kinoshita, Hidetaka; Akutsu, Atsushi*; Nishikawa, Masaaki*; Fukuda, Shimpei
Proceedings of 12th International Topical Meeting on Nuclear Applications of Accelerators (AccApp '15), p.255 - 260, 2016/00
Kondo, Yasuhiro; Morishita, Takatoshi; Yamazaki, Saishun; Hori, Toshihiko; Sawabe, Yuki; Chishiro, Etsuji; Fukuda, Shimpei; Hasegawa, Kazuo; Hirano, Koichiro; Kikuzawa, Nobuhiro; et al.
Physical Review Special Topics; Accelerators and Beams, 17(12), p.120101_1 - 120101_8, 2014/12
We performed a beam test of a new radio frequency quadrupole linac (RFQ III) for the beam current upgrade of the Japan Proton Accelerator Research Complex. First, the conditioning of RFQ III was conducted, and after 20 h of conditioning, RFQ III became very stable with a nominal peak power and duty factor of 400 kW and 1.5%, respectively. An off-line beam test was subsequently conducted before installation in the accelerator tunnel. The transmission, transverse emittance, and energy spread of the 50-mA negative hydrogen beam from RFQ III were measured and compared with simulation results. The experiment and simulation results showed good agreement; therefore, we conclude that the performance of RFQ III conforms to its design.
Kawane, Yusuke*; Miura, Akihiko; Miyao, Tomoaki*; Hirano, Koichiro; Sugimura, Takashi*; Kato, Yuko; Sawabe, Yuki; Fukuda, Shimpei; Ouchi, Nobuo
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1288 - 1291, 2014/10
In the J-PARC Linac, because an upgrading of a beam current up to 50mA using an RF-driven ion source and a new RFQ Linac cavity is in progress, we have developed a new frontend equipments. In order to protect the scraper against 50 mA, we need to observe the temperature and to avoid the excess heat loading of the scraper surface and to count the irradiated beam particles. We also monitor the beam transmission between the upstream and downstream of the chopper cavity to check the chopping errors using the beam current monitors. We fabricated the interlock system for the temperature, irradiated particle numbers and beam transmission. And we tested them in the test stand with actual beam. This paper describes the interlock system and their test results.
Ozawa, Akira*; Matsuta, Kensaku*; Nagatomo, Takashi*; Mihara, Mototsugu*; Yamada, Kazunari*; Yamaguchi, Takayuki*; Otsubo, Takashi*; Momota, Sadao*; Izumikawa, Takuji*; Sumikama, Toshiyuki*; et al.
Physical Review C, 74(2), p.021301_1 - 021301_4, 2006/08
no abstracts in English
Meigo, Shinichiro; Oi, Motoki; Fujimori, Hiroshi*; Kawasaki, Tomoyuki; Nishikawa, Masaaki; Fukuda, Shimpei
no journal, ,
no abstracts in English
Oi, Motoki; Hosokawa, Hidemitsu*; Nishikawa, Masaaki*; Fukuda, Shimpei; Teshigawara, Makoto; Meigo, Shinichiro; Takada, Hiroshi
no journal, ,
At J-PARC, a neutron production target is installed in the helium vessel, and 3-GeV proton beams are delivered from a 3-GeV synchrotron to the target through a beamline with high vacuum environment. A proton beam window (PBW) is installed to isolate the helium vessel from the proton beamline. Since the PBW is degraded by radiation damage, it is scheduled to be replaced every 2 or 3 years under the 1-MW operation. In the summer outage in 2017, the PBW #2 was replaced to #3. A shielding cask was used for transferring the activated PBW, while hands-on works were done to remove the cooling water pipes at the top of the shielding plug of PBW. Since the cooling water contains 510 Bq/cc of tritium, it was drained from the pipes and the pipes were dried before removing PBW. The hands-on work was carried out in a green-house with a local exhaust device to prevent scattering of radioactive materials. In this presentation, we report the replacement work of the PBW including safety measures.