Spectroscopic Studies of an Electron-Beam-Produced Plasma

Abstract

An electron beam operating in medium-pressure gases has been constructed, and its operating characteristics investigated. Helium, neon and argon have been excited by the electron beam, and it has been found that for lower pressures, less than 1 torr in the case of helium, accelerated electrons directly excite the ionic excited level. The population densities in the neutral series levels have been observed up to n＝15, and have been found to be roughly proportional to n⁻⁴. A possible explanation is proposed that is based on a direct excitation from the ground state and a depopulation by l-changing collisions.