AbstractThe use of rf ion sources in neutral beam injection (NBI) systems offers reduced maintenance and cost due to the absence of filaments. For the first time high-power rf positive ion sources have been put in operation recently in a real NBI system on a tokamak. The performance of the new system is equivalent to that of a conventional one with arc discharge sources. Due to the relevance for ITER, rf sources are also being investigated in context with negative ions: 8.5 mA/cm2 H− have been achieved so far in a non-optimised version.
Development of large RF driven negative ion sources for neutral beam injection