Observation of anode ions associated with pinching in a relativistic electron beam diode

Abstract

Ions originating at the anode of a relativistic electron beam (REB) accelerator are observed at the cathode by a means of a Faraday cup. The dominant species is H⁺, probably from adsorbed impurities. These ions, having energies equal to the diode voltage, are not observed until 20–40 J/cm² are deposited by the beam on the anode surface, and are closely associated with the formation of a pinch at the anode.