Characteristics of a High Current P.I.G. Ion Source at Low Gas Pressure

The characteristics of a 10 cm P.I.G. (Penning ionization gauge) discharge and its application as an ion source at a low pressure are given. Using a hot cathode two regions of operation are found, one above and the other below 1 micron. Pulsed ion current reaching 1 Ampere could be extracted from this source through a 10 cm diameter gridded cathode at a discharge current of about 20 Amperesand a gas pressure of 0.5 micron. The cathode discharge current was found to contain electrons. The ion current to the reflector cathode is about 10% of the discharge current.