| Two electron beam sustained discharge lasers are studied. The first electron beam excitation scheme exploits direct electron impact excitation of the laser levels responsible for the blue-green transitions in Ar II. The second utilizes selective excitation, of a red transition in the mercury ion via resonant charge transfer between neutral mercury and helium ions in the negative glow of a hollow cathode discharge.;First, a self-consistent model of an argon ion laser excited by low energy (50-200 eV) dc electron beams is discussed. The motivation for this work was to determine the feasibility of developing an argon ion laser with improved efficiency in comparison to positive column devices. Optical gains, powers and laser efficiencies were computed for the 4765, 4880, 4965 and 4658 ;The model predicts small signal gain coefficients which are in agreement with experimental measurements at low current densities. Laser output powers calculated at higher current densities where gain measurements were not available also agree with experimental results. Efficiencies of approximately 4 ;Secondly, a DC hollow cathode discharge helium mercury laser is studied. The model discussed here is the first self consistent description of a hollow cathode discharge. Parameters free for adjustment in the model are the voltage, the gas pressures, and cathode material, as is the case for actual laboratory devices.;The model self-consistently calculates the discharge current by computing the spatial evolution of the energies of charged particles in the cathode sheath and the corresponding electron energy distribution and ion densities in the negative glow. The laser gain, output power, and efficiency are calculated as a function of discharge current and voltage, buffer gas pressure, and metal vapor density.;Optimal discharge conditions, in terms of laser output power, were determined to be a buffer gas pressure of 16 Torr and a mercury vapor pressure of 0.2 Torr. The results provided by the model are in good agreement with experimental measurements obtained by other researchers. |
