Present Status and Future Upgrades of the J-PARC Ring RF Systems

J-PARC is the multipurpose research institutes. 10 years have passed since the user operation started. We have been considering the upgrades for the future and the target beam powers for 3 GeV rapid cycling synchrotron (RCS) and 30GeV Main ring (MR) are 1.5MW and 1.3MW. To achieve a 1.5MW of RCS output beam power, increasing the number of Linac proton particles is necessary. For accelerating such higher beam current, the rf systems in the RCS need to upgrade an accelerating voltage and to take account of heavier beam loading. In case of the MR, increasing the number of proton is not appropriate from the viewpoint of space charge effects. We chose to shorten the MR cycle time. The required RF voltages become almost double. All nine systems have been replaced with the higher accelerating gradient RF systems using a newly developed magnetic alloy material. At present, the proton beam of 470kW is being delivered with a cycle time of 2.48s. Beam powers of MR will plan to aim first at 750KW after replacing the magnet power supplies. But, to realize a 1.3MW beam power, upgrading the RF power sources will be necessary. We present the ring RF system status and their upgrades for the future.
Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada