Operation status of the J-PARC H ion source

Oguri, Hidetomo  ; Ueno, Akira  ; Ikegami, Kiyoshi*; Namekawa, Yuya; Okoshi, Kiyonori 

A cesium-free H ion source driven with a LaB filament is being operated for J-PARC. The beam commissioning of J-PARC accelerators started in November 2006. As of June 2009, there have been 25 beam commissioning or supply runs. In these runs, the ion source has been successfully operated in two different modes. One is a low beam current mode, in which approximately 5 mA is produced. The other is a high beam current mode, in which approximately 30 mA is produced. According to the task of the run, one of the two modes was selected. Since the beam current can be maintained within a few percent errors by tuning the ion source parameter once a day, 24 hours beam operation with an ion source operator only in day time was started in April 2008. The total interruption time during the runs due to the ion source failure is approximately 50 hours as of June 2009. The availability of the ion source is calculated to be 99%. The interruptions were mainly caused by the insufficient lifetime of the filament. By a few modifications on the filament shape administered until August 2007, we succeeded in achieving the lifetime of 2,030 hours, which included 1,250 hours in the low beam current mode and 780 hours in the high beam current mode.