A review of recent H− ion source work at Rutherford Appleton Laboratory

The ion source used at ISIS is a surface plasma source of the Penning type, and routinely produces 35 mA of H− ions during a 200 μs pulse at 50 Hz for uninterrupted periods of up to 50 days. Identical sources have now also been run on both the ISIS RFQ test stand and a dedicated ion source development rig (ISDR). Details of the most recent results from each of these three applications will be presented, along with physical explanations for the observed differences in source behaviour.