Status and upgrade plan of Linac and RCS in J-PARC

Kamiya, Junichiro   ; Hasegawa, Kazuo; Kinsho, Michikazu  ; Oguri, Hidetomo  ; Yamamoto, Kazami   

In J-PARC, the beam with a power of 500 kW has been stably provided to the MLF for the past year. High availability of 94% during the MLF user operation was achieved in the fiscal year of 2018. Many efforts to reduce downtime causes have been performed such as rejection of undesirable large signals of the beam loss monitors by optimizing a time constant in the circuit, and stabilization of DTL operation of DTL by the cavity cleaning, etc. In addition, trial operations at 1 MW were recently achieved. The accelerator group has begun to consider upgrades for the future operation with more than 1 MW beam power, such as an improvement of the Medium Energy Beam Transport 1 (MEBT1) for optimal beam matching, a reinforcement of the RF system in the RCS, and so on. In this presentation, summary of the current status and upgrade plans for higher beam power operation of the Linac and the RCS will be described.