Advanced uses of a current transformer and a mult-wire profile monitor for online monitoring of the stripper foil degradation in the 3-GeV RCS of J-PARC

Saha, P. K.   ; Harada, Hiroyuki  ; Hatakeyama, Shuichiro; Hayashi, Naoki  ; Hotchi, Hideaki  ; Kinsho, Michikazu  ; Okabe, Kota  ; Saeki, Riuji; Yamamoto, Kazami   ; Yamazaki, Yoshio ; Yoshimoto, Masahiro  

We have established an advanced and sophisticated uses of a current transformer and a multi-wire profile monitor for accurate measuring as well as online monitoring of the waste beam so as to know the stripper foil degradation during user operation of the J-PARC 3-GeV RCS. A sudden foil breaking is not only decreases accelerator availability but also raises maintenance issues. A proper monitoring system of the foil is thus important in order to avoid any such issues by replacing the foil with a new one in the scheduled maintenance day. A single foil was used for a continuous last 7 months operation of the RCS with an extracted beam power of 300 kW (18 kW injected beam). There were a total of 810E23 hit particles but there was no any degradation of the foil so far. Surprisingly an increase of the foil thickness of about 10% was observed.