A compact high-current microwave-driven ion source

A simple, compact, high-current, 2.45 GHz microwave ion source has been built and tested. The source uses permanent magnets rather than electrical solenoids to provide the required magnetic field. Developed from an earlier microwave-driven ion source, the plasma generator volume has been reduced by a factor of 8 with no discernible change in rf efficiency or feed consumption. A hydrogen beam of over 60 mA has been extracted from a single 5 mm diameter aperture with a proton fraction of 80% at a rf power of 450 W and a gas flow of 1.5 sccm.