Production of Intense Proton Beams

An ion source system employing mass selection has been developed for use in the terminal of an accelerator. The beam from a duoplasmatron is accelerated to 40 keV and focused by an einzel lens through a 200 permanent magnet inflector. A beam waist is formed at a 6.35 mm rejection aperture located on the acceleration axis. Dispersion is sufficient to provide a proton beam of greater than 99% purity. Proton currents up to 7 mA were obtained during bench testing. Performance demonstrations on the Dynamitron accelerator at the University of Birmingham have shown proton beam power in excess of 6 kw at energies from 2 to 3 MeV.