Upgrade of the control and interlock systems for the magnet power supplies in the T2K primary beamline

T2K is a long-baseline neutrino oscillation experiment at J-PARC in Japan. A high intensity neutrino/antineutrino beam is generated and propagates 295km to Super-Kamiokande. The high intensity proton beam which reached 350 kW in May 2015, is extracted from the Main Ring synchrotron and guided through a primary proton beamline to a graphite target using normal-conducting (NC) magnets and super-conducting combined-function magnets. In October 2014, we replaced all of the power supplies (PSs) for the NC magnets with newly developed PSs. We also developed a new control system based on the Experimental Physics and Industrial Control System (EPICS) and PLC, putting emphasis on the safe operation of power supplies, and integrated it into the existing interlock system. Consequently the latency time for the interlock system was improved. We report the actual implementation and operation results of these developments. (author)