Operation status of the J-PARC negative hydrogen-ion source

Oguri, Hidetomo  ; Ikegami, Kiyoshi*; Okoshi, Kiyonori ; Koizumi, Isao; Namekawa, Yuya*; Ueno, Akira  ; Takagi, Akira*; Yamazaki, Saishun

The J-PARC was extensively damaged by the earthquake in March 2011. The ion source had some damages such as dew condensation on the ion source surface due to the flooding in the accelerator tunnel, vacuum leakage due to the breaking of the viewing port and vacuum pump failure due to the strong quake. The restoration work was accomplished on schedule, and the linac beam operation was restarted in December 9th. The ion source supplies the beam to the accelerator without serious aftereffects of the earthquake. Availability of the ion source is one of the important issues because it is directly related to the operation time of the J-PARC. To evaluate the lifetime of the present ion source, we started 2 months beam operation. The results of recent four beam runs show the ion source is capable of continuous operation for approximately 1,200 hours with the beam current of 17 mA. For another attempt to enhance the ion source availability, we tried to decrease the time for maintenance to replace consumable elements. By unitizing the replacement elements and keeping them under the vacuum condition until just before the installing, the maintenance is completed within 24 hours without any beam performance degradation of the ion source.