Status of the J-PARC linac

Hasegawa, Kazuo

Beam commissioning of the J-PARC linac started in November 2006 and 181 MeV acceleration was successfully achieved in January 2007. The linac had delivered beams for commissioning of accelerators and experimental facilities. Trip rates of the RFQ, however, unexpectedly increased in Autumn 2008, and that was the primary limitations of the operation days and power ramp up. We tried to recover by improvement of vacuum properties, tender conditioning and so on. By taking these measures, we can lengthen the continuous operation days and stand user operations. We ramped up the beam power from 20 kW to 120 kW for 3 GeV beam users in November 2009. This corresponds to the linac beam power of 7.2 kW and the linac has delivered beams at this power since then without significant troubles. And also we successfully demonstrated 300 kW at 3 GeV for 1 hour in December. We present the performance and operation experiences of the J-PARC linac.