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Nakanoya, Takamitsu; Yoshimoto, Masahiro; Saha, P. K.; Takeda, Osamu*; Saeki, Riuji*; Muto, Masayoshi*
Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.937 - 941, 2023/11
In the J-PARC 3GeV Rapid Cycling Synchrotron (RCS), the 400MeV H
beam is changed to H+ beam by a charge exchange foil and accelerated to 3GeV. So far, RCS had used two types of charge exchange foil. One is the HBC (Hybrid Boron mixed Carbon) foil and the other is the Kaneka GTF (Graphene Thin Film). HBC foil is a patented deposition method developed at KEK for the stable production of thick carbon foil. Initially, the RCS used HBC foil produced atKEK. However, in 2017, JAEA had started HBC foil production and has been using it since then. Recently, we have succeeded in depositing thick pure carbon foil, which had been considered difficult to produce by the arc deposition method. As a new challenge, this pure carbon foil was used in the user operation from March 2023. As a result, Pure carbon foils showed less deformation and more stable charge exchange performance than HBC and GTF.
Nakanoya, Takamitsu; Yoshimoto, Masahiro; Saha, P. K.; Takeda, Osamu*; Saeki, Riuji*; Muto, Masayoshi*
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.629 - 633, 2023/01
In the J-PARC 3-GeV Rapid Cycling Synchrotron (RCS), a 400 MeV H- beam injected from the linac is exchange to an H+ beam by a charge exchange foil and accelerated to 3 GeV. The charge exchange foils mainly used in the RCS are HBC foil (Hybrid Boron mixed Carbon stripper foil), which are made by adding a small amount of boron to carbon rods and using them as electrodes by the arc deposition method. Since 2018, foils produced by JAEA have been used for user operation. So far, no major problems have occurred due to the foils. Meanwhile, the beam power of the RCS has been gradually increased from 500 kW to 830 kW since 2018. As beam power increases, the foil issues were identified to achieve the RCS design power of 1 MW. In this paper, we will report on the recent foil usage status and issue in the user operation.
Yamamoto, Kazami; Hayashi, Naoki; Okabe, Kota; Harada, Hiroyuki; Saha, P. K.; Yoshimoto, Masahiro; Hatakeyama, Shuichiro; Hotchi, Hideaki; Hashimoto, Yoshinori*; Toyama, Takeshi*
Proceedings of 54th ICFA Advanced Beam Dynamics Workshop on High-Intensity, High Brightness and High Power Hadron Beams (HB 2014) (Internet), p.278 - 282, 2015/03
Rapid Cycling Synchrotron (RCS) of Japan Proton Accelerator Complex (J-PARC) is providing more than 300 kW of proton beam to Material and Life science Facility (MLF) and Main Ring (MR). Last summer shutdown, a new ion source was installed to increase output power to 1 MW. In order to achieve reliable operation of 1 MW, we need to reduce beam loss as well. Beam quality of such higher output power is also important for users. Therefore we developed new monitors that can measure the halo with higher accuracy. We present beam monitor systems for these purposes.
Kinsho, Michikazu
Proceedings of 5th International Particle Accelerator Conference (IPAC '14) (Internet), p.3382 - 3384, 2014/07
Big issue for the J-PARC rapid cycling synchrotron (RCS) was displacement of main magnets caused by last big earthquake because this made beam loss more than 400 kW beam power. Since realignment of main magnets and other components was essential to realize higher beam power and stable operation, this work has been done during maintenance period in 2013. To achieve the nominal performance 1MW beam power at the RCS and 0.75 MW at the MR, beam energy of linac was increased from 181 MeV to 400 MeV with a new accelerating structure ACS (Annular-ring Coupled Structure) linac from this January. It was successful 400 MeV beam injection and 3 GeV beam extraction at the RCS, and user operation has been performed with beam power of 300 kW. An equivalent beam power of 560 kW with a beam loss of only 0.3% could be achieved during short time for high intensity beam study.
Kamiya, Junichiro; Ueno, Tomoaki*; Takayanagi, Tomohiro
IEEE Transactions on Applied Superconductivity, 16(2), p.1362 - 1365, 2006/06
Times Cited Count：5 Percentile：33.52(Engineering, Electrical & Electronic)Kicker magnets in J-PARC RCS are being constructed at JAERI (Japan Atomic Energy Research Institute) as the extraction pulse magnet. It is designed to have a large aperture in order to accept the maximum beam power 1MW. Therefore the impedance mismatch and fringe field have the large effect on distortion of a flatness of the kicker magnetic field. We examined their effect by the simulation and measurement, and contrived to improve the field flatness. In this paper, we present the features of the RCS kicker systems, describe the magnetic field measurement and improvement, and briefly introduce the field mapping which we are performing now.
Takayanagi, Tomohiro; Kamiya, Junichiro; Watanabe, Masao; Yamazaki, Yoshishige; Irie, Yoshiro; Kishiro, Junichi; Sakai, Izumi*; Kawakubo, Toshimichi*
IEEE Transactions on Applied Superconductivity, 16(2), p.1358 - 1361, 2006/06
Times Cited Count：16 Percentile：60.87(Engineering, Electrical & Electronic)The injection bump system of the 3-GeV RCS in J-PARC consists of the pulse bending magnets for the injection bump orbit, which are four horizontal bending magnets (shift bump), four horizontal painting magnets (h-paint bump), and two vertical painting magnets (v-paint bump). In this paper, the design of the magnets and power supply of the injection bump system are reported.
Takayanagi, Tomohiro; Kamiya, Junichiro; Watanabe, Masao; Ueno, Tomoaki*; Yamazaki, Yoshishige; Irie, Yoshiro; Kishiro, Junichi; Sakai, Izumi*; Kawakubo, Toshimichi*; Tounosu, Shigeki*; et al.
IEEE Transactions on Applied Superconductivity, 16(2), p.1366 - 1369, 2006/06
Times Cited Count：8 Percentile：43.72(Engineering, Electrical & Electronic)The injection system of the 3-GeV RCS in J-PARC is composed of four main orbit bump magnets (shift bump) to merge the injection beam with the circulating beam. The magnetic field design and the structural analysis of the shift bump magnets have been performed using 3D magnetic and mechanical codes. In this paper, the design of the bending magnets is reported.
Takayanagi, Tomohiro; Irie, Yoshiro; Kamiya, Junichiro; Watanabe, Masao; Watanabe, Yasuhiro; Ueno, Tomoaki*; Noda, Fumiaki*; Saha, P. K.; Sakai, Izumi*; Kawakubo, Toshimichi*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.1048 - 1050, 2005/00
The pulse bending magnets for the injection system of the 3-GeV RCS in J-PARC has been designed. The injection system consists of the pulsed bending magnets, which are four horizontal bending magnets (shift bump) and four horizontal painting magnets (h-paint bump) for the injection bump orbit, and two vertical painting magnets (v-paint magnet). The injection beam energy and the extraction beam power are 400 MeV and 1 MW at 25 Hz repetition rate, respectively. The acceptance to include the injection beam, the painting beam and the circulating beam at the shift bump points is a 388 mm wide and a 242 mm high. The shift bump has been designed using a 3D magnetic analysis code, which accomplished less than 0.4 % field deviation under 0.26 T excitation level.
Takahashi, Hiroki; Sakaki, Hironao; Sako, Hiroyuki; Yoshikawa, Hiroshi; Kato, Yuko*; Sugimoto, Makoto*; Kawase, Masato*
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.233 - 235, 2004/08
3GeVRCS send the beam of a different parameter to both the institutions of MLF and 50GeVMR. Therefore, 3GeVRCS Control System is required to supervise by distinguishing the beam for every institution correctly. Moreover, since a parameter change is made during continuation operation, without suspending an accelerator, it is required that the beam loss by operation should be reduced as much as possible. This report shows the examination and design situation of 3GeVRCS control system that aim at these realizations.
Kawase, Masato*; Yoshikawa, Hiroshi; Sakaki, Hironao; Takahashi, Hiroki; Sako, Hiroyuki; Kamiya, Junichiro; Takayanagi, Tomohiro; Hongo, Reiji*
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.537 - 539, 2004/08
When an interlock occurs in the equipment, it is required to notify the upper rank control system of the Interlock and receive information for apparatus information in the upper rank control system as at high speed as possible. In the apparatus using FA-M3, it can respond to this by using the notice function of an event. This report shows the event notification system with a PLC based Kicker electromagnet power supply for 3GeVRCS.
Kinsho, Michikazu; Saito, Yoshio*; Kabeya, Zenzaburo*; Tajiri, Keisuke*; Nakamura, Tomaru*; Abe, Kazuhiko*; Nagayama, Taketoshi*; Nishizawa, Daiji*; Ogiwara, Norio
Vacuum, 73(2), p.187 - 193, 2004/03
Times Cited Count：17 Percentile：54.92(Materials Science, Multidisciplinary)Alimina ceramics vacuum duct has been developing at JAERI for the 3GeV-RCS of the J-PARC project. There are two type of the alumina ceramics vacuum ducts, one is a 1.5m-long duct with a circular cross section for use in the quadrupole magnet, the other is a 3.5m-long being bending 15 degree with an elliptical cross section for use in the dipole magnet.These ducts could be manufactured by brazed jointing several duct segments of 0.5-0.8 m long. Since some electrically conductive boundary is necessary to form on the ceramics duct in order to reduce the duct impedance, the alumina ceramics ducts have copper stripes on the outside surface of the ducts. This is called for rf shielding system. The copper stripes as rf shielding is produced by an electroforming method. In order to reduce emitting secondary electrons when primary protons or electrons impinge onto the surface, TiN film is coated inside surface of the alumina ceramics duct.
Kinsho, Michikazu; Ogiwara, Norio; Wada, Kaoru*; Yoshida, Motoo*; Nakayasu, Tatsuo*; Yamato, Yukio*
Vacuum, 73(2), p.175 - 180, 2004/03
Times Cited Count：4 Percentile：20.5(Materials Science, Multidisciplinary)The turbo molecular pump which can be operated exposed to high radiation has been developing at JAERI and Osaka Vacuum Ltd., because it is planed to use this turbo molecular pump for the 3GeV-RCS of the J-PARC project. The goal of irradiation dose is 30 MGy because the cumulative energy dose due to radiation is approximately estimated to be on the order of 100 MGy for 30 years of the 3GeV-RCS operation. In order to know radiation damage of turbo molecular pump, gamma-ray irradiation experiment has been performed at JAERI. The turbo molecular pump could operate properly less than 3.5 MGy absorption dose under gamma-ray irradiation environment. Since the elongation of elastomer vacuum seals became small due to exposed to radiation, this radiation damage of elastomer seals causes leak. The turbo molecular pump components except the elasomer seals, for example motor coil, control sensor, and etc, have kept high performance more than 7 MGy absorption dose. The turbo molecular pump without elastomer seals has been developed and the irradiation test will be started form April.
Irie, Yoshiro
Proceedings of 9th European Particle Accelerator Conference (EPAC 2004), p.113 - 117, 2004/00
The MW proton source using rapid cycling synchrotron (RCS) has many challenging aspects, such as (1) large aperture magnets and much higher RF voltages per turn due to a low energy injection and a large and rapid swing of the magnetic field, (2) field tracking between many magnet-families under slightly saturated conditions, (3) RF trapping with fundamental and higher harmonic cavities, (4) H- charge stripping foil, (5) large acceptance injection and extraction straights, (6) beam loss collection, and (7) beam instabilities. These are discussed in details mainly on the basis of the J-PARC 3GeV RCS, which is under construction in Japan. Issues (3) to (7) are common with another scheme of MW spallation neutron source, i.e. full-energy linac + accumulator ring. Comparisons with the SNS design in the US are then made. Reliability/availability of these machines is very important theme which finally determines the successful operations. From the experiences in the existing machines, we will discuss the factors necessary toward the better performance.
Kamiya, Junichiro; Takayanagi, Tomohiro; Nakamura, Eiji*; Shimada, Taihei; Suzuki, Hiromitsu; Kawakubo, Toshimichi*; Shigaki, Kenta*; Murasugi, Shigeru*; Tazawa, Shichiro*
Dai-14-Kai Kasokuki Kagaku Kenkyu Happyokai Hokokushu, p.84 - 86, 2003/11
no abstracts in English
Yamamoto, Kazami; Hatakeyama, Shuichiro*
no journal, ,
The J-PARC 3-GeV Rapid Cycling Synchrotron (RCS) aims to deliver 1 MW proton beam to the materials and life science experimental facility (MLF) and the main ring synchrotron. In such a high intensity beam, there is a possibility to cause a severe radiation accident. To detect and prevent the radiation accident in the accelerator system, we developed the beam diagnostics system in RCS. This system includes a monitoring and interlock system of an abnormal state of the extraction beam to the mercury target of MLF. The radiation level of the gas in the tunnel were able to always observed by connecting radiation safety system and accelerator control system. Various kind of parameters, such as dump temperatures, radiation monitors, beam positions can be checked by one monitor to compare the influence each other.
