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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：7 Percentile：78.30(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.
Ogiwara, Norio; Suganuma, Kazuaki; Hikichi, Yusuke; Nishikawa, Masaaki; Yanagibashi, Toru; Kamiya, Junichiro; Kinsho, Michikazu
Journal of the Vacuum Society of Japan, 56(5), p.159 - 162, 2013/05
nodulesHakoyama, Tsuneo*; Oi, Ryo*; Hazuma, Kazuya*; Suga, Eri*; Adachi, Yuka*; Kobayashi, Mayumi*; Akai, Rie*; Sato, Shusei*; Fukai, Eigo*; Tabata, Satoshi*; et al.
Plant Physiology, 160(2), p.897 - 905, 2012/10
Times Cited Count：31 Percentile：67.94(Plant Sciences)Togashi, Tomohito; Watanabe, Masao; Suganuma, Kazuaki; Takayanagi, Tomohiro; Ueno, Tomoaki; Tani, Norio; Watanabe, Yasuhiro; Kinsho, Michikazu
Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.471 - 473, 2012/08
The 3-GeV RCS (Rapid Cycling Synchrotron) of J-PARC (Japan Proton Accelerator Research Complex) uses 8 pulse kicker magnets for the beam extraction at a repetition rate of 25 Hz. Each kicker power supply has 2 thyratrons and thus they are 16 in total. An average life time of thyratrons even more than the J-PARC annual operation time of 5000 hours and a stable operation with a downtime of less than only 0.5% has already been achieved. The present maintenance procedures and statistics for the long term operation with thyratrons are reported in this paper.
Ogiwara, Norio; Suganuma, Kazuaki; Hikichi, Yusuke; Nishikawa, Masaaki; Yanagibashi, Toru; Kamiya, Junichiro; Kinsho, Michikazu
Proceedings of 3rd International Particle Accelerator Conference (IPAC '12) (Internet), p.487 - 489, 2012/05
Kamiya, Junichiro; Ogiwara, Norio; Nishikawa, Masaaki; Hikichi, Yusuke; Yanagibashi, Toru; Suganuma, Kazuaki
Journal of the Vacuum Society of Japan, 55(4), p.156 - 159, 2012/04
It is usually difficult to reduce outgassing of a large structure inside a vacuum chamber by baking the whole chamber, which causes the large extension of the chamber and needs a lot of heater power. The solution is to rise the temperature of structure object without heating the vacuum chamber. This means to install heat source inside the chamber and increase the heat quantity to the object by inserting the heat shield between the object and the chamber. In the particle accelerator field, there are a lot of such requirements for reducing outgassing of structures inside vacuum chambers. One example is a kicker magnet, which is installed in a vacuum chamber and consists mainly of ferrite cores and aluminum electric plates. We applied the above method to the outgassing reduction of the kicker. In this article, we show outline of this in-situ bake-out method, the effects of the heat shield on the heat quantity and the result of the outgassing reduction.
Togashi, Tomohito; Watanabe, Masao; Suganuma, Kazuaki; Takayanagi, Tomohiro; Ueno, Tomoaki; Tani, Norio; Watanabe, Yasuhiro
Proceedings of 7th Annual Meeting of Particle Accelerator Society of Japan (DVD-ROM), p.579 - 583, 2010/08
The 3-GeV RCS (Rapid Cycling Synchrotron) at J-PARC (Japan Proton Accelerator Research Complex) has the pulse kicker power supply system which uses the thyratron switches for beam extraction. There were many troubles caused by unstable operation of thyratrons after beam commissioning started in January 2009. The, failure rate of the kicker power supply system was about 13%. To improve this status, we have been managed the operations of the thyratron in detail. As a result, the unstable operation has been improved and the failure rate has been achievement less than 0.5% (Run33) in April, 2010. In this paper, we report current status of the thyratron operation of the kicker power supply system.
Watanabe, Masao; Kamiya, Junichiro; Suganuma, Kazuaki; Takayanagi, Tomohiro; Tani, Norio; Togashi, Tomohito; Ueno, Tomoaki; Watanabe, Yasuhiro
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.3296 - 3298, 2010/05
3 GeV rapid cycling synchrotron of J-PARC accelerates proton beams from the 181 MeV up to 3 GeV. Proton beams in the RCS are fast extracted by kicker magnets at the repetition rate of 25 Hz. The rise time of the magnetic field is approximately 260 ns due to the propagation time through the coaxial cable and the kicker magnet itself. The flat top length of it is required to 840 ns in order to extract two beam bunches. Pulse forming lines (PFL) and thyratrons are used to make the rise time and the flat top, at the maximum charging voltage of 80 kV. 16 thyratrons are used in the eight power supplies of the kicker system. Since thyratrons are gaseous discharge switching devices, they often make misfire or self-breakdown in several hours. In this paper, present status of operation and voltage adjustment method of the reservoir and cathode heater power supply of the thyratrons in the kicker system are described.
Ogiwara, Norio; Kinsho, Michikazu; Kamiya, Junichiro; Yamamoto, Kazami; Yoshimoto, Masahiro; Hikichi, Yusuke; Kanazawa, Kenichiro; Mio, Keigo; Takiyama, Yoichi; Suganuma, Kazuaki; et al.
Vacuum, 84(5), p.723 - 728, 2009/12
Times Cited Count：7 Percentile：29.49(Materials Science, Multidisciplinary)To minimize the radiation exposure during maintenance, it is necessary to compose the 3-GeV RCS vacuum system with reliable components which have long life time in such a high level of radiation. In addition, it is necessary to keep the operating pressure with beam in ultra high vacuum for suppressing the pressure instability. Thus we should think of not only the outgassing mainly due to ion desorption but also the pumping efficiency. From the above, the vacuum system was designed. The ring is divided by the isolation valves into 6 sections, which can be pumped down independently. For avoiding any eddy current loss ceramic ducts are used in the bending and focusing magnets. These ducts are connected to the Ti ducts, putting the Ti bellows between. Here, we adopt pure Ti as a material for the ducts and bellows because of its small residual radioactivity. The ring is evacuated with 20 ion pumps (0.7 m
/s) and 24 turbomolecular pumps (TMPs) (1.3 m/s), which are attached to the Ti ducts. The TMPs are used for not only rough pumping but also evacuation during the beam operation. Especially a collimator system for localizing beam losses in a restricted area is evacuated with the TMPs, because the outgassing from this region will be probably the largest. On the other hand, each arc section is pumped by 4 ion pumps and 2 TMPs. To realize the above system, we have developed some components such as large aperture ceramic ducts and TMPs with high radioactive-resistance, as well as several kinds of heat treatment to reduce the outgassing. Finally, we have realized the UHV without baking in the RCS and the beam operation has been succeeded until now.
Ogiwara, Norio; Suganuma, Kazuaki; Hikichi, Yusuke; Kamiya, Junichiro; Kinsho, Michikazu; Sukenobu, Satoru*
Journal of Physics; Conference Series, 100, p.092024_1 - 092024_5, 2008/00
Times Cited Count：4 Percentile：81.18(Nanoscience & Nanotechnology)Pure Ti is adopted as a material for ducts and bellows at the 3 GeV-RCS in J-PARC project, because of its small residual radioactivity. In the particle accelerator, the H
outgassing due to ion impact is often dominant gas release. As the reduction of hydrogen content probably leads to the suppression of ion induced desorption, we intend to reduce the hydrogen content in the Ti by in-situ vacuum baking. First of all, thermal desorption behavior and the change in hydrogen content have been investigated. The vacuum firing over than 550
C is effective to reduce the hydrogen content in the Ti. The mechanical properties have been also monitored because a grain growth leads to the decrease of mechanical strength. Even after the treatment at 750C for 12 h the decreases in tensile and yield strength are so small (
10%) that we have no anxiety about the reduction of mechanical strength. Based upon this study, the vacuum firing has been applied for the RCS machine.
Suganuma, Kazuaki; Hikichi, Yusuke; Ogiwara, Norio; Sukenobu, Satoru*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.346 - 348, 2008/00
Pure Ti is adopted as a material for ducts and bellows at the proton accelerator 3 GeV-RCS in J-PARC project, because of its small residual radioactivity. We intended to apply vacuum firing to reduce the hydrogen content in the Ti. The firing at temperatures higher than 550C was effective in reducing the hydrogen content in the Ti. At the same time, we have measured the mechanical properties because grain growth leads to decrease in mechanical strength. Even after treatment at 750C for 8 hr, the decreases in tensile and yield strength were so small (10%) that we have no anxiety about the reduction of mechanical strength. Based on the above results, to reduce the hydrogen content, the Ti bellows and ducts for the RCS have been vacuum fired at 650C for 8 hr and at 750C for 8 hr, respectively.
Kanazawa, Kenichiro; Ogiwara, Norio; Suganuma, Kazuaki; Inohara, Takashi*; Wada, Kaoru*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.391 - 393, 2008/00
no abstracts in English
Ogiwara, Norio; Suganuma, Kazuaki; Miyo, Yasuhiko; Kobayashi, Shinichi*; Saito, Yoshio*
Applied Surface Science, 146(1-4), p.234 - 238, 1999/00
Times Cited Count：7 Percentile：41.49(Chemistry, Physical)no abstracts in English
Uehara, Kazuya; Ikeda, Yoshitaka; Saigusa, Mikio; Sakamoto, Keishi; Fujii, Tsuneyuki; Maebara, Sunao; Tsuneoka, Masaki; Seki, Masami; Moriyama, Shinichi; Kobayashi, Noriyuki*; et al.
Fusion Engineering and Design, 19(1), p.29 - 40, 1992/07
Times Cited Count：1 Percentile：17.03(Nuclear Science & Technology)no abstracts in English
Ikeda, Yoshitaka; Imai, Tsuyoshi; Sakamoto, Keishi; Honda, Masao; ; Maebara, Sunao; Sawahata, Masayuki; Suganuma, Kazuaki; Suzuki, Norio; Tsuneoka, Masaki; et al.
AIP Conference Proceedings 159, p.119 - 122, 1987/00
no abstracts in English
Matsue, Masaki*; Arakawa, Satoru*; Tanaka, Toshihiro*; Sawa, Soji*; Ogiwara, Norio; Suganuma, Kazuaki
no journal, ,
At the 3 GeV-RCS in J-PARC project, pure Ti is adopted as a material for bellows. The space available for the bellows is so narrow that the requirements are hard. To make the hydro-formed bellows like the welded ones, it is essential to bend and press the Ti plates and to keep the 2 sides facing each other in close contact. The repetition of the combination of bending (pressing) with annealing enables us to realize the close contact of Ti plates. We produced the experimental bellows with the inner diameter of 50 mm. It shows suitable performance: (1) spring rates are 1.5 N/mm (axial) and 4.0 N/mm (lateral), respectively; (2) endurance test shows the fatigue life of over than 1 million cycles with the displacement of 20 mm. Thus we have succeeded in developing the hydro-formed bellows with the same flexibility as the welded ones. Now we have completed the performance tests about the prototype of the large bellows (400 mm in a diameter), and mass production has been performed.
Hakoyama, Tsuneo*; Oi, Ryo*; Hazuma, Kazuya*; Suga, Eri*; Adachi, Yuka*; Kobayashi, Mayumi*; Akai, Rie*; Sato, Shusei*; Fukai, Eigo*; Tabata, Satoshi*; et al.
no journal, ,
Ogiwara, Norio; Kinsho, Michikazu; Kamiya, Junichiro; Yamamoto, Kazami; Suganuma, Kazuaki; Yoshimoto, Masahiro; Saito, Yoshio*
no journal, ,
