Results from experimental studies of x-ray emission during gas discharges are reported. They confirm experimentally the presence of runaway electrons in short, high-pressure discharges under highly overvolted conditions. These electrons, when stopped at the anode, produce x-ray radiation. A high-energy component above 3 keV was measured. The effects of the type of gas, its pressure, electrode separation, and applied voltage are presented. The results are analyzed with respect to breakdown development described by a model based on two groups of electrons present in the discharge.

• Received 28 June 1982

DOI:https://doi.org/10.1103/PhysRevA.26.2826