Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Nobuta, Yuji*; Yokoyama, Kenji; Kanazawa, Jun*; Yamauchi, Yuji*; Hino, Tomoaki*; Suzuki, Satoshi; Ezato, Koichiro; Enoeda, Mikio; Akiba, Masato
Journal of Nuclear Materials, 417(1-3), p.607 - 611, 2011/10
Times Cited Count：2 Percentile：18.25(Materials Science, Multidisciplinary)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：30.11(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.
Takayanagi, Tomohiro; Kanazawa, Kenichiro; Ueno, Tomoaki; Someya, Hirohiko*; Harada, Hiroyuki*; Irie, Yoshiro; Kinsho, Michikazu; Yamazaki, Yoshishige; Yoshimoto, Masahiro; Kamiya, Junichiro; et al.
IEEE Transactions on Applied Superconductivity, 18(2), p.306 - 309, 2008/06
Times Cited Count：10 Percentile：50.72(Engineering, Electrical & Electronic)The four shift bump magnets (BUHS01-04) of the 3-GeV RCS in J-PARC, which are located at the long straight section, produce a fixed main bump orbit to merge the injection beam into the circulating beam. They are realized with four magnets connected in series to form the accurate closed bump orbit. However, the total integrated magnetic field of the four magnets is not zero because of the magnetic field interferences between the shift bump magnet and the adjacent quadrupole magnet (Q magnet). In order to decrease the imbalance of the integrated magnetic field, 0.3mm insulators were inserted at the median plane of the return yoke of the second and third shift bump magnets (BUHS02 and BUHS03). The integrated field has been decreased from 2358.0 Gauss-cm to -71.6 Gauss-cm, resulting in the closed orbit distortion of the beam to be decreases from 6.0 mm to less than 1.0 mm.
Takayanagi, Tomohiro; Kanazawa, Kenichiro; Ueno, Tomoaki; Someya, Hirohiko*; Harada, Hiroyuki*; Irie, Yoshiro; Kinsho, Michikazu; Yamazaki, Yoshishige; Yoshimoto, Masahiro; Kamiya, Junichiro; et al.
IEEE Transactions on Applied Superconductivity, 18(2), p.310 - 313, 2008/06
Times Cited Count：2 Percentile：20.16(Engineering, Electrical & Electronic)The beam painting injection system of the 3-GeV RCS in J-PARC, which realizes the uniform beam distributions in the ring, consists of four horizontal paint bump magnets and two vertical paint magnets. Each paint bump magnet power supply is required to excite the current with high accuracy that varies from 17.6 kA to zero during 0.5 msec. The IGBT chopper units, the switching frequency of which is 50 kHz each, are multiple connected to achieve the effective carrier frequency of 600 kHz. The output accuracy is then achieved to be less than 1 %. The measurements of the magnetic field with the actual current waveform were performed and the good performance was confirmed.
Yoshimoto, Masahiro; Ueno, Tomoaki; Togashi, Tomohito; Takeda, Osamu; Kanazawa, Kenichiro; Watanabe, Masao; Yamazaki, Yoshio; Kamiya, Junichiro; Takayanagi, Tomohiro; Kuramochi, Masaya; et al.
IEEE Transactions on Applied Superconductivity, 18(2), p.297 - 300, 2008/06
Times Cited Count：4 Percentile：30.85(Engineering, Electrical & Electronic)Yoshimoto, Masahiro; Ueno, Tomoaki; Togashi, Tomohito; Toyokawa, Ryoji; Takeda, Osamu; Watanabe, Masao; Yamazaki, Yoshio; Yamamoto, Kazami; Kamiya, Junichiro; Takayanagi, Tomohiro; et al.
IEEE Transactions on Applied Superconductivity, 18(2), p.301 - 305, 2008/06
Times Cited Count：1 Percentile：12.87(Engineering, Electrical & Electronic)Shirasu, Noriko; Yamashita, Toshiyuki; Kanazawa, Hiroyuki; Kimura, Yasuhiko; Sudo, Kenji; Magara, Masaaki; Inagawa, Jun; Kono, Nobuaki; Nakahara, Yoshinori
JAERI-Research 2001-018, 23 Pages, 2001/03
JAERI-Research-2001-018.pdf:1.48MB
no abstracts in English
