Emission Spectra and Self-Terminating Lasers of Electron-Beam-Produced Rare Gas Plasmas

Abstract

Plasmas of rare gases (He through Xe) were produced by a short-pulsed, high-current electron beam (600 kV, 10 kA peak, 3 ns FWHM) in a drift tube without an external field over a wide range of pressure (0.l～80 Torr). Emission spectra of the plasmas were observed between 2500 and 8500 Å with a spectrograph and bandpass filters in the directions of end- and side-on views. Short-pulsed laser emissions (3 ns FWHM, 10～400 W peak) traveling along with the electron-beam pulse were found for 20 spectral lines of singly-ionized and neutral Ne, Ar, Kr, and Xe atoms through the end window of the drift tube. The small signal gain coefficients were measured. Temporal behaviors of the emission intensity were observed for the laser lines as well as for many other spontaneous lines through the side window. The atomic processes for the laser excitations have been examined.