CERN Accelerating science

Article
Title	Low Level RF Control System of J-PARC Synchrotrons
Author(s)	Tamura, Fumihiko ; Anami, Shozo ; Ezura, Eizi ; Hara, Keigo ; Nomura, Masahiro ; Ohmori, Chihiro ; Schnase, Alexander ; Takagi, Akira ; Yamamoto, Masanobu ; Yoshii, Masahito
Affiliation	(JAERI, Chiba-ken) ; (JAERI, Ibaraki-ken) ; (JAERI/LINAC, Ibaraki-ken) ; (KEK, Ibaraki)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.3624
Subject category	Accelerators and Storage Rings
Abstract	We present the concept and the design of the low level RF (LLRF) control system of the J-PARC synchrotrons. The J-PARC synchrotrons are the rapid cycling 3-GeV synchrotron (RCS) and the 50-GeV main ring (MR) which require very precise and stable LLRF control systems to accelerate the ultra-high proton beam current. The LLRF system of the synchrotron is a full-digital system based on the direct digital synthesis (DDS). The functions of the system are (1) the multi-harmonic RF generation for the acceleration and the longitudinal bunch shaping, (2) the feedbacks for stabilizing the beam, (3) the feedforward for compensating the heavy beam loading, and (4) other miscellaneous functions such as the synchronization and chopper timing. The LLRF system of the RCS is now under construction. We present the details of the system. Also, we show preliminary results of performance tests of the control modules.