Negative ion yield in long pulse operation of the KAMABOKO III source

In Cadarache development on negative ion sources is being carried out on the KAMABOKO III ion source on MANTIS in collaboration with JAERI, Japan. The target performance indicated in the ITER R&D task description is to accelerate a D− beam, with a current density of 200A/m2 and <1 electron extracted per accelerated D− ion, at an injected power ranging between 1 and 2kWl−1 of source volume, and a source pressure of 0.3Pa. For ITER a continuous ion beam must be assured for pulse lengths of up to 3600s.