Present status and future plan of the J-PARC RCS injection bump system

Each power supply of the injection bump system at the J-PARC (Japan Proton Accelerator Research Complex) 3-GeV RCS (Rapid Cycling Synchrotron) has been upgraded along with the 400 MeV injection beam energy of the LINAC (Linear Accelerator). In January 2015, RCS has been demonstrated 1-MW high power beam by using the upgraded power supply. However, after one month, a fixing bolt of the shift bump magnet coil was dropped, and the water leakage of the cooling pipe of the connection conductor bar was occurred. Furthermore, depending on a high power beam, a current fluctuation of the paint bump power supply has been confirmed. On the other hand, a high residual dose of the injection area has been clarified. In order to install a shield in the injection area, the structural changes of the shift bump magnet and the division of the shift bump power supply are considered, respectively. This paper reports the present status and future plan of the injection bump system. (author)