Development and present status of new horizontal shift bump power supply for injection bump at the J-PARC RCS

Takayanagi, Tomohiro   ; Ueno, Tomoaki; Horino, Koki; Hayashi, Naoki  ; Kinsho, Michikazu  ; Okabe, Kota  ; Irie, Yoshiro*

The new shift bump (SB) power supply which doubled power supply capacity has been developed and manufactured according to upgrading of 400MeV injection beam energy of the LINAC (Linear accelerator) in J-PARC (Japan Proton Accelerator Research Complex) 3-GeV RCS (Rapid-Cycling Synchrotron). The power supply adopted a capacitor commutation method to form the trapezoid waveform pattern (bump waveform) by the IGBT (Insulated Gate Bipolar Transistor) switch. The test operation was started in January, 2014. However, the trouble of a diode in the FT-unit (Flat top unit) was frequent and the user operation of the J-PARC was started without the FT-unit. As a result, the flat-top part of the bump waveform was became a downward, and it has been to a formation defectiveness wave pattern. Therefore, using a horizontal paint bump magnet and a pulse steering magnet, the beam injection point of the RCS was fixed. This paper will be reported the characteristic, the trouble and the user operation about the new shift bump power supply.