Precise adjustment of the injection painting for the high-intensity proton beam in the J-PARC RCS

Kato, Shinichi; Harada, Hiroyuki  ; Takayanagi, Tomohiro   ; Horino, Koki; Tobita, Norimitsu; Ueno, Tomoaki*; Kinsho, Michikazu  

In the J-PARC RCS, the multi-turn charge-exchange injection scheme is adopted. In addition, the painting injection method which arranges the injection beam on the wide phase-space area during the multi-turn injection has been performed to expand the circulating beam. This method is essential to mitigate the beam loss caused by the particles scattered at the charge-exchange foil and the space charge force. This method is performed by the 4 horizontal and 2 vertical deflection magnets. Hence, the accuracy of the painting injection depends on the power adjustment precision of the magnet power supply. Therefore, the output power adjustment application was developed in order to achieve the high precise painting injection. This application was developed based on the examination results of the output characteristics of the power supply. As a result, the adjustment time was reduced and the adjustment precision was improved to twice of the original design value. After that, the painting injection adjustment was performed using the application. As a result, it was confirmed that the high precise painting injection was achieved.