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Kondo, Yasuhiro; Hasegawa, Kazuo; Ueno, Akira
Proceedings of 23rd International Linear Accelerator Conference (LINAC 2006) (CD-ROM), p.749 - 757, 2007/00
no abstracts in English
Sato, Susumu; Tomisawa, Tetsuo; Kondo, Yasuhiro; Ueno, Akira; Akikawa, Hisashi*; Igarashi, Zenei*; Lee, S.*; Kubota, Chikashi*; Ikegami, Masanori*
Proceedings of 23rd International Linear Accelerator Conference (LINAC 2006) (CD-ROM), p.268 - 270, 2007/00
In the J-PARC LINAC, upgrade of beam diagnostics of LEBT and MEBT is taken. Three beam current monitors and two beam phase monitors are added. In the LEBT and MEBT section, large number of accelerator devices are placed. Therefore to save the space, several modifications are needed, for example, additional monitors need to be welded with each other. Those details of the upgrade of beam diagnostics system are described.
Kobayashi, Tetsuya; Chishiro, Etsuji; Anami, Shozo*; Michizono, Shinichiro*; Yamaguchi, Seiya*
Proceedings of 23rd International Linear Accelerator Conference (LINAC 2006) (CD-ROM), p.583 - 585, 2007/00
Installation of the J-PARC linac machines (Phase I) has been almost completed and the beam commissioning will be started in December this year. The error of the accelerating field must be within 
1 degree in phase and 1% in amplitude. Thus, high phase stability is required as an RF reference. Our objective concerning the phase stability of the reference aims at less than 0.3 degrees. Last year the installation of the RF reference distribution system was completed. The reference signal is optically distributed to all of the low-level RF control systems by using E/O, O/E, Optical Amplifier and Optical Couplers and so on. The performance of this system was evaluated. The phase stability of 0.06 degrees was obtained.
Michizono, Shinichiro*; Anami, Shozo*; Yamaguchi, Seiya*; Fang, Z.*; Kobayashi, Tetsuya; Suzuki, Hiroyuki
Proceedings of 23rd International Linear Accelerator Conference (LINAC 2006) (CD-ROM), p.574 - 576, 2007/00
Twenty high power klystrons are installed in the J-PARC linac. The requirements for the rf field stabilities are 1% in amplitude and 1 deg. in phase during a 500 
s flat-top. In order to satisfy these requirements, we adopt the digital feedback and feed-forward system with FPGAs and a commercial DSP board. The FPGAs (Virtex-II 2000) enable a fast PI control for a vector sum of two cavity fields. The measured stability during rf pulse was 0.15% in amplitude and 0.15 degree in phase. The tuner control was successively operated by a way of the DSP board by measuring the phase difference between the cavity input wave and the cavity field. Beam loading effects were emulated using a beam-loading test box. By proper feed-forward, the rf stability was less than 0.3% and 0.15 degree.
Ito, Takashi; Asano, Hiroyuki; Morishita, Takatoshi; Yamazaki, Yoshishige; Tanaka, Hirokazu*; Naito, Fujio*; Kato, Takao*; Takasaki, Eiichi*
Proceedings of 23rd International Linear Accelerator Conference (LINAC 2006) (CD-ROM), p.740 - 742, 2007/00
For the J-PARC (Japan Proton Accelerator Research Complex) linac, an SDTL (Separated type Drift Tube Linac) is used to accelerate an H
ion beam from 50 MeV to 191 MeV. We have measured the RF characteristics of the SDTL tanks and adjusted the field distribution. The measured Q value was above 90% of an ideal SUPERFISH value. Furthermore the field distribution was adjusted within 1% for all the tanks.
Ito, Takashi; Asano, Hiroyuki; Morishita, Takatoshi; Yamazaki, Yoshishige; Naito, Fujio*; Takasaki, Eiichi*; Yoshino, Kazuo*; Tanaka, Hirokazu*; Kato, Takao*; Kabeya, Zenzaburo*; et al.
Proceedings of 23rd International Linear Accelerator Conference (LINAC 2006) (CD-ROM), p.782 - 784, 2007/00
Three DTL tanks and 32 SDTL tanks for the Japan Proton Accelerator Research Complex (J-PARC) were assembled at KEK site. After the assembling, the high-power conditioning of the DTL1 and 12 SDTL tanks and the beam acceleration test for the DTL1 ware carried out. And then all the DTL and SDTL tanks have to be transported form KEK to JAEA. In order to confirm the effect of the transportation to the drift tube alignment, we measured the displacement of the drift tube positions before and after the transportation by using a prototype cavity. As a result of the test, the measured displacement of the drift tubes by the transportation was less than 0.02mm which is consistent in the measurement accuracy. Based on this result, all the DTL and SDTL tanks were transported form KEK to JAEA.