APPARATUS FOR GENERATING AN ELECTRON BEAM

摘要

Apparatus is described for generating an electron beam in the presence of a gas at a pressure higher than 100 Pa. The apparatus comprises an acceleration gap defined between a metallic cathode 18 having a flat surface spaced by a uniform predetermined distance from a metallic anode (20). A cable pulse generator applies a steep edged high voltage pulse by way of a transmission line (10) to the acceleration gap. The length of the acceleration gap is determined in dependence upon the peak voltage of the applied pulse, the rise time of the leading edge of the applied pulse and the capacitance of the acceleration gap in such manner as to generate a run-away current between the cathode and the anode.