Electron-beam generation in a wide-aperture open gas discharge: A comparative study for different inert gases

In the present study, electron-beam generation by open discharges was examined. The study was performed at gas pressures up to 20 Torr, and covered all inert gases. At voltages up to 8 kV, electron-beam currents up to 1600 A with current density similar to 130 A/cm(2) and a beam generation efficiency in excess of 93% were obtained. The production of electrons from cold cathode was concluded to be of photoemissive nature, enabling the production of high-intensity electron beams in any noble gas or in a mixture of a noble gas with molecular gases irrespective of cathode material. (C) 2010 American Institute of Physics. [doi:10.1063/1.3485051]