Results of the CEA/Saclay H electron cyclotron resonance ion source, ECRIN

A 2.45 GHz electron cyclotron resonance test stand based on a pure volume H- (negative) ion production is actually under development at CEA Saclay. The negative ion source is working in a pulsed mode, 2 ms at 5-10 Hz. The first H- ions have been observed at the beginning of 2002 with a poor efficiency: only a few microamperes were produced. Several changes inside the plasma chamber have increased the production rate of negative ions up to several milliamperes. A biased grid separates the plasma chamber into two regions. In the first part, we produce excited H2 molecules that are necessary for producing in the second zone H- ions by a dissociative attachment process located near the extraction zone. Qualitative and quantitative beam diagnostics allow measuring several beam parameters and analyzing the effect of gas mixing or materials on the H- production rate