A Multiampere DuoPIGatron Ion Source

An ion source consisting of a duoplasmatron feeding a PIG discharge system has been built and is named a duoPIGatron. The extraction electrodes, located at the end of the PIG discharge opposite the duoplasmatron, are accel-decel with a 5 cm diam and multiapertures. The source is simple, flexible, and efficient. 1 A beams are extracted in steady-state operation with ion energies from 1.5 to 5 keV. 4 A beams are extracted with 0.1 sec pulses and a 10% duty cycle at ion energies of 20 to 40 keV. At 30 to 40 keV, about 60% of the ion beam is within a half-angular divergence of 1.2° with no magnetic lens. Using a hydrogen gas cell this system produces 2.6 A (equivalent) of 17.5 and 35 keV H0 particles within a half-angular divergence of 1.2°. One of the present limitations in scaling the source to larger beams is the current capabilities of the power supplies. As larger supplies are available attempts will be made to scale this system to the 10 A beam modules needed for future fusion research.