A Direct Extraction H- Ion Source

A direct extraction H
^-
ion source of the Penning design described by Dudnikovl has been built and tested. To date a beam of 108 mA has been extracted from a 10 × 0.5 mm
²
slit and transported through a 90° bending magnet into a Faraday cup at a duty factor of ~7 Hz × 700 μs (0.5%). The duty factor limitation is imposed by operating temperature requirements so that at reduced arc current a dc beam of 4 mA has been reached.