First new power supply of main magnet for J-PARC main ring upgrade

Japan Proton Accelerator Research Complex (J-PARC) aims at achieving a MW-class proton accelerator facility. One of the promising solutions for increasing the beam power is to shorten the repetition period of Main Ring (MR) from current rating of 2.48 sec to 1.3 sec in the future. However, in this scheme, there are serious concerns for the main magnets power supply that the output voltage and the power variation on the electric system are increasing. We have considered that the energy recovery scheme based on the capacitive energy storage is one of the best solution to compensate the power variation induced by a magnet power supply. In order to apply the higher output voltage, choppers are connected in series. In order to realize precise output current regulation, a passive filter is used to reduce the ripples caused by the IGBT switching and low noise control system. We developed and installed the first new power supply for the main magnet in the summer of 2016. In this paper, the first new power supply for the main magnet in J-PARC MR is reported including the test result. (author)