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Yokota, Wataru; Nara, Takayuki; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Yuyama, Takahiro; Ishizaka, Tomohisa; Agematsu, Takashi; Uno, Sadanori; Chiba, Atsuya; et al.
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.22 - 24, 2008/08
no abstracts in English
Sugimoto, Hiroshi*; Okamoto, Hiromi*; Wei, J.*; Yuri, Yosuke; Sessler, A. M.*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.436 - 438, 2008/00
no abstracts in English
Suzuki, Hiroyuki; Chishiro, Etsuji; Kobayashi, Tetsuya; Hori, Toshihiko; Yamazaki, Masayoshi; Anami, Shozo*; Yamaguchi, Seiya*; Kawamura, Masato*; Fukui, Yuji*; Fang, Z.*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.467 - 469, 2008/00
no abstracts in English
Hori, Toshihiko; Yamazaki, Masayoshi; Chishiro, Etsuji; Suzuki, Hiroyuki; Ao, Hiroyuki; Hirano, Koichiro; Hasegawa, Kazuo; Yamaguchi, Seiya*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.482 - 484, 2008/00
no abstracts in English
Hasegawa, Katsushi; Hara, Keigo*; Nomura, Masahiro; Omori, Chihiro*; Schnase, A.; Tamura, Fumihiko; Toda, Makoto*; Yamamoto, Masanobu; Yoshii, Masahito*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.394 - 396, 2008/00
The RF cavity using Magnetic Alloy (MA) cores has been developed for achieving the high field gradient in J-PARC synchrotron. Because of adopting the quality factor of 26, cut core configuration has been used in Main Ring RF cavities. Electromagnetic simulations of HOM analysis about RF cavity of MA cores, cut core configuration and between the cut core gap were performed. In this paper, a simulation method of MA core and results of HOM analysis for cut core and MA core are presented.
Ueno, Tomoaki; Takayanagi, Tomohiro; Kinsho, Michikazu; Yoshimoto, Masahiro; Kamiya, Junichiro; Watanabe, Masao
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.355 - 357, 2008/00
The injection bump power supply of J-PARC 3GeV RCS is composed of the assemblies that are multiple connection with IGBT choppers, and It can make optionally current wave form. But the high-frequency noise due to the switching of the IGBT choppers has caused the damages to the control system and the monitor system. So the ground wires that connect to each power supply panel and each magnet has been changed to copper sheets. As a result, the noise decreases rapidly and it kept balance controllable.
Takahashi, Hiroki; Sakaki, Hironao; Yoshikawa, Hiroshi; Ito, Yuichi; Suzuki, Takahiro
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.262 - 264, 2008/00
J-PARC Timing System is the scheduled timing as the basis of the 25Hz trigger clock defined by the LUT. The LUT is set in advance before receiving the trigger clock and contains delay words. At the original design, the change of LUT was not required synchronous and simultaneity. And if these are required, it is considered that these requirements are accomplished by "type operation". But, the result of the further study for components and facility operation shows that it is necessary of synchronous and simultaneity of LUT changes, in addition, it is difficult to accomplish the all accelerator operation by only "type operation". Therefore, at the data of RCS monitor, it is shown importance to effectively use the timing information to distinguish MLF beam and MR beam. Then we designed the new timing system which is added to the Reflective Memory to the original design, and we could develop the timing system which is able to accommodate the additional requirements.
Nomura, Masahiro; Tamura, Fumihiko; Schnase, A.; Yamamoto, Masanobu; Hasegawa, Katsushi; Shimada, Taihei; Suzuki, Hiromitsu; Ezura, Eiji*; Hara, Keigo*; Toda, Makoto*; et al.
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.246 - 248, 2008/00
We have been developing MA core for J-PARC Ring RF Cavity. From long run tests, we found that poor electrical isolation between layers caused damages to the cores. We improved the electrical isolation mainly by introducing a smooth tension control system to the winding process. The degree of the each core's electrical isolation was evaluated by the results of DC resistance and radial RF impedance measurements. After long run tests of all of the cores, we installed 10 RF cavities in a tunnel in May 2007 and beam commissioning was started from October 2007. Until now, total operation time of the RF cavities in the tunnel is about 1500 hours. To check the condition of the cores, we measured the RF cavity impedance at intervals of beam operations. The result of impedance measurements shows that no impedance reduction related to core damage was observed.
Kobayashi, Tetsuya; Anami, Shozo*; Michizono, Shinichiro*; Fang, Z.*; Suzuki, Hiroyuki; Yamaguchi, Seiya*; Chishiro, Etsuji
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.488 - 490, 2008/00
For the J-PARC linac low level RF system, in order to compensate beam-loading change by pulses in the operation of 25-Hz repetition, a function that switches the feed-forward control parameters in every pulse were installed into the digital accelerating-field control system. The linac provides a 50-mA peak current proton beam to a 3-GeV rapid-cycling synchrotron (RCS). Then the RCS distributes the 3-GeV beam into a following 50-GeV synchrotron (main ring, MR) and the Materials and Life Science Facility (MLF), which is one of the experimental facilities in the J-PARC. The 500-us long macro pulses from the ion source of the linac should be chopped into medium pulses for injection into the RCS. The duty (width or repetition) of the medium pulse depends on which facility the RCS provides the beam to the MR or MLF. Therefore the beam loading compensation needs to be corrected for the change of the medium pulse duty in the 25-Hz operation.
Hotchi, Hideaki; Kinsho, Michikazu
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.4 - 6, 2008/00
The J-PARC 3GeV RCS (Rapid Cycling Synchrotron) has been commissioned since September 2007. The initial tuning of the basic parameter has been completed in February 2008, and then since May 2008 the RCS beam has been supplied to the succeeding MR (50GeV Main Ring) and MLF (Material and Life Science Facility) for their commissioning. We have achieved 52 kW output so far. Now the RCS is in transition to the challenging phase for aiming at the higher current operation. Our immediate goal is to realize the stable operation with 100 kW output which corresponds to 10% of the designed output beam power.
Hikichi, Yusuke; Ogiwara, Norio
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.343 - 345, 2008/00
no abstracts in English
Fang, Z.*; Anami, Shozo*; Michizono, Shinichiro*; Yamaguchi, Seiya*; Kobayashi, Tetsuya; Suzuki, Hiroyuki
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.476 - 478, 2008/00
In the J-PARC proton linac, each klystron drives two RF cavities. The RF amplitude and phase of the cavities are controlled by an FPGA-based digital feedback control system. The tuning of each cavity is also controlled by a DSP of this control system. In this paper, three methods of f
setting of RF cavity will be discussed. The tuning method of RF cavity with flat cavity-phase decay is adopted in the actual operation of the J-PARC linac. In our RF system, the tuning information including detuned frequency and phase, and Q-value of each cavity are measured in real-time and displayed in the PLC Touch Panel of the control system.
Schnase, A.; Ezura, Eiji*; Hara, Keigo*; Hasegawa, Katsushi; Nomura, Masahiro; Omori, Chihiro*; Shimada, Taihei; Suzuki, Hiromitsu; Takagi, Akira*; Tamura, Fumihiko; et al.
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.340 - 342, 2008/00
Iijima, Hokuto; Nagai, Ryoji; Nishimori, Nobuyuki; Hajima, Ryoichi
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.604 - 606, 2008/00
We report an experimental result of measuring a mid-infrared FEL optical pulse by means of frequency-resolved optical gating (FROG) and a comparison with a numerical simulation result. The measurement was performed at JAEA ERL-FEL with the perfect synchronism condition. The FEL optical pulse was measured to be 0.6 ps of the pulse duration and 4.6 THz of the bandwidth. The simulation results were 0.5 ps and 4.4 THz, respectively. The measurement result was good agreement with the simulation result within a measurement error. The chirp in frequency domain followed a cubic function. This behavior is the so-called "self-chirp", which is not caused by a dispersive material but relation of electron-bunch parameters and FEL-undulator parameters.
Hajima, Ryoichi; Nagai, Ryoji; Iijima, Hokuto; Nishimori, Nobuyuki; Honda, Yosuke*; Muto, Toshiya*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.607 - 609, 2008/00
We review R&D status of the high-brightness electron gun for future ERL light sources.
Sakanaka, Shogo*; Kobayashi, Yukinori*; Sato, Kotaro*; Kasuga, Toshio*; Kawata, Hiroshi*; Hajima, Ryoichi; Nakamura, Norio*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.225 - 227, 2008/00
Collaborative research efforts towards future ERL-based light sources are carried out. We present the R&D status of an electron gun and superconducting cavities, updated design study on the test facility (Compact ERL).
Shinto, Katsuhiro; Vermare, C.*; Harami, Taikan*; Sugimoto, Masayoshi; Garin, P.*; Maebara, Sunao; Sakaki, Hironao; Ohira, Shigeru; Okumura, Yoshikazu; Mosnier, A.*; et al.
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.255 - 258, 2008/00
Yuri, Yosuke; Ishizaka, Tomohisa; Yuyama, Takahiro; Okumura, Susumu; Ishibori, Ikuo
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.397 - 399, 2008/00
no abstracts in English
Hirano, Koichiro; Ao, Hiroyuki; Morishita, Takatoshi; Asano, Hiroyuki; Hori, Toshihiko; Yamazaki, Masayoshi; Kobayashi, Tetsuya; Kubota, Chikashi*; Yamazaki, Yoshishige
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.497 - 499, 2008/00
An ACS (Annular Coupled Structure) module has been developing for the 190-MeV to 400-MeV part of the J-PARC Linac. We have conducted the high power test of the first ACS module which consists of two accelerating tanks with 17 cells and a bridge tank with 9 cells. This paper describes results of the high power RF tests. The module achieved an average axial accelerating gradient of E0 = 4.5 MV/m at 1.8 MW RF input power, 0.6 ms pulse width, and 50 Hz repetition rate.
Yamazaki, Masayoshi; Chishiro, Etsuji; Kobayashi, Tetsuya; Hori, Toshihiko; Suzuki, Hiroyuki; Anami, Shozo*; Kawamura, Masato*; Fukui, Yuji*; Nammo, Kesao*; Fang, Z.*; et al.
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.485 - 487, 2008/00
no abstracts in English
