15 cm duoPIGatron ion source

The 10-cm (grid diameter) duoPIGatron ion source produces pulsed hydrogen ion beams of 10 to 15 A beam current in the 20- to 40-keV energy range for a duration of a few tenths of a second. To fulfill the requirements of the next generation of high-power neutral beam injectors for heating plasmas in CTR devices, this source has been enlarged to a version 15-cm in grid diameter. In addition, by utilizing a magnetic multipole line cusp field confinement method, the plasma created is characterized over the 15 cm grid diameter by a noise level within +- 10 percent and spatial density variations within +- 15 percent at a density on the order of 1012 cm-3. This larger source has operated reliably and produced a beam current exceeding 30 A of hydrogen at 27 keV. Initial operation of a 20-cm version of this source employing line cusp confinement has produced an extraction current of 60 A at 33 keV