Status of injection energy upgrade for J-PARC RCS

Hayashi, Naoki  ; Harada, Hiroyuki  ; Hotchi, Hideaki  ; Kamiya, Junichiro   ; Saha, P. K.   ; Shobuda, Yoshihiro   ; Takayanagi, Tomohiro   ; Tani, Norio  ; Yamamoto, Kazami   ; Yamamoto, Masanobu   ; Yamazaki, Yoshio ; Yoshimoto, Masahiro  ; Watanabe, Masao  ; Watanabe, Yasuhiro  ; Toyama, Takeshi*

The injection energy upgrade from 181 to 400 MeV for J-PARC RCS is planned in 2013. One power supply was replaced and using for a normal operation. An IGBT chopper type power supply which has larger switching noise will be changed to a capacitor bank type. New injection system allows the center injection with 400 MeV and switching painting area. As further steps for the leakage field, it begins to diminish the effect from the beam transport line. A quadrupole corrector system is designed and fabricated to compensate the beta beat due to the injection bump as the first step. Two profile monitors will be modified to correct position systematic errors and third one is going to be installed at dispersion free section. It is important to minimize kicker impedance lower, which may cause the beam instability. A diode, which has high reverse breakdown voltage and works with lower forward voltage, has been developed. Using this new diode, an experiment shows the impedance becomes lower.