Penning discharge as a photoelectric EUV spectroscopy source

Abstract

A Penning discharge was investigated photoelectrically as a light source from 100 A to 300 A. The source showed reasonable stability-10% over an hour's operation. Bright spectral lines observed were a mixture of lines from the filling gas (Ne) and from sputtered cathode material (Al). The discharge was found to be an intense line source; an estimate of the brightness of the 160 A Al IV lines shows them to be comparable with the highly ionized metal lines appearing in a pulsed tokamak discharge. Satellites of the Al IV resonance lines at 160 A appear clearly in the spectra.