Low level RF control system for J-PARC RCS

Tamura, Fumihiko   ; Schnase, A.; Nomura, Masahiro  ; Yamamoto, Masanobu   ; Yoshii, Masahito*; Anami, Shozo*; Ezura, Eiji*; Hara, Keigo*; Omori, Chihiro*; Takagi, Akira*

We describe the low level RF (LLRF) control system for the J-PARC Rapid Cycling Synchrotron (RCS). The LLRF system is required to be very stable and precise to achieve the high accelerating beam current. The system has the functions of the multi-harmonic RF generation, the feedback loops, the beam loading compensation, and other miscellaneous functions. The fully-digital LLRF system of the RCS is now under construction. The preliminary test results are also shown.