BNL volume H− sources

An H− current of up 30 mA has been extracted from a 1 cm2 aperture in a 20 cm diameter volume source with a conical filter field. From a 9.7 cm diameter version of this source, an H− current of up to 35 mA was extracted from a 0.5 cm2 aperture. In both sources, the electron‐to‐H− ratio is typically <10, and often <5.