Ion source for neutral beam injection meant for plasma and magnetic field diagnostics.

At the Lawrence Berkeley National Laboratory a diagnostic neutral beam injection system for measuring plasma parameters, flow velocity, and local magnetic field is being developed. The system is designed to have a 90% proton fraction and small divergence with beam current at 5-6 A and a pulse length of approximately 1 s occurring once every 1-2 min. The ion source needs to generate uniform plasma over a large (8 x 5 cm(2)) extraction area.