Recent Status of RF Source In J-PARC Linac

RF sources for the low beta linac section use 324-MHz klystrons. After the evaluation of prototype tubes, mass production of 21 tubes are completed. These are installed in the linac building from April 2005. Performances of the 324 MHz klystrons are described in this paper. A prototype klystron of 972-MHz klystron, which is planed to be installed in high beta linac section, oscillated strongly without any drive rf power, and it had been investigated to solve it. Though it was suspected to be a gun oscillation at first, it was showed to be a drift-tube oscillation in recent experiment. After this experiment, we built a new tube and started to test it. This experimental result is written in this paper. Other status of construction related to the klystron power supply also shows in this paper.