Precise current adjustment of the power supply for the injection painting magnets in the J-PARC RCS

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

For the high intensity proton accelerator, the mitigation of the space charge force is most important because it causes the beam loss. For mitigation, 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 in the J-PARC RCS. In the horizontal plane, the position and angle of the injection beam are fixed and these of the circulating beam are changed during the painting injection. Specifically, the time variation of the bump orbit height at the injection point is generated by the 4 paint bump magnet whose power supply are separate. Hence, the accuracy of the painting injection depend on the power conditioning precision of the magnet power supply. Therefore, the output characteristics of the power supply was examined for the precise power conditioning. In addition, the automatic conditioning tool has been developed based on that results.