Hydrogen arc discharge cleaning of accelerator tubes

Accelerator tubes manufactured by NEC were cleaned by the hydrogen arc discharge method and tested on the NEC 3-MV test accelerator. We will discuss the results of this testing program. Generally, we confirm the favorable experience previously obtained by Korschinek, et al. The familiar microdischarge exhibited by normal tubes are largely elminated in arc duscharge cleaned tubes. Thus, the arc discharge process has the same observable effect as voltage conditioning. This result suggests that the hydrogen discharge is effective in removing carbon and hydrocarbons from the surface of the accelerator tube.