State of the art online monitoring system for the waste beam in the rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

Saha, P. K.   ; Hatakeyama, Shuichiro; Yamamoto, Kazami   ; Yoshimoto, Masahiro  ; Harada, Hiroyuki  ; Hotchi, Hideaki  ; Shobuda, Yoshihiro   ; Kinsho, Michikazu  ; Sato, Kenichiro*; Irie, Yoshiro*

In order to monitor the waste beam in the H0 beam dump of the RCS of J-PARC, we have established a rather precise method recently. The fast Fourier transformation (FFT) analysis of the raw signal of a Current Transformer (CT) and then picking up the amplitude of the power spectrum corresponding to the frequency of the intermediate pulses of the injected beam gives the desired beam signal. While the raw signal of the CT contains a large noise and quite impossible to identify the beam signal, the present method is found to be a very powerful and accurate. The beam signal is clearly distinguished by one of magnitude higher as compared to the background signal and has been using for realtime monitoring of the waste beam, which is very important for observation of the foil life time, dump limit as well as stability of the linac beam itself.