Fast electrons from Grimm glow discharge helium plasmas

Pulsed high voltages with a maximum of 5 kV were applied to the Grimm glow discharge lamp using helium gas. Strong radiation of the continuous X-rays and the characteristic X-rays from thr window materials of Al and Zr thin films was observed. We consider that the high-energy electron, namely, the runaway electron, emitted from the cathode surface passed right through the hollow anode and bombarded the X-ray window, resulting in the X-ray emission. This electric discharge lamp is expected to be useful as a new electron and soft-X-ray source.