Digital RF feedforward systems for beam loading compensation in JKJ synchrotrons

Tamura, Fumihiko; Yamamoto, Masanobu; Yoshii, Masahito*; Schnase, A.*; Omori, Chihiro*; Uesugi, Tomonori*

Proceedings of 8th European Particle Accelerator Conference (EPAC 2002), p.2106 - 2108, 2002/00

We present the concept and the design of the high-speed digital RF feedforward systems for beam loading compensation in the synchrotrons of JAERI-KEK Joint Project (JKJ). JKJ synchrotrons are high intensity proton synchrotrons at the energy of 3 and 50 GeV, in which beam loading compensation systems are necessary. Beam loading compensation is to be realized by full-digital RF feedforward systems. We describe the implementation details of the feedforward systems. The system consists of a down-converter, digital filters, and an up-converter. We present two possible implementations of the filters; one uses ASIC filter chips and the other uses FPGA.