Performance of injection beam position monitors in the J-PARC RCS

Hayashi, Naoki  ; Saha, P. K.   ; Toyama, Takeshi*

It is important to monitor the injected beam trajectory and position into a synchrotron ring. In the J-PARC RCS, there are two specialized beam position monitors (BPM) in the first arc section in order to perform continuous monitoring. They detect the linac RF frequency 324 MHz or its second harmonics, these contributions quickly decrease after a few turns in the ring. Therefore, they are mostly sensitive just injected beam. The RCS adopts the multi-turn injection and painting. These monitors are useful to check the transverse painting process.