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.
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