: This report describes our research program directed toward the identification of new high-performance electronic transition lasers, and toward the detailed characterization of these laser media. An extensive theoretical and experimental survey has been conducted, emphasizing molecules whose excited states are ionic in character. Several promising new candidates have been identified; the laser potential of some of these has been investigated in detail (ICl, RgHg, and HgCl); others should be the subjects of further investigation (e.g., the cadmium and zinc halides). Perhaps the most important accomplishment reported here is the demonstration (in collaboration with Maxwell Laboratories Inc.) of an electron-beam-controlled-discharge HgCl laser. This report describes the experimental studies which led to this achievement, and points out several areas in which further research is needed. Considerable progress has been made in characterizing the microscopic processes which dominate the performance of electron-beam pumped XeF lasers. Specific attention has been paid to identifying and measuring the rates for the most important reactions which lead to the formation of XeF*. The role of the XeF* state which emits the prominent 460 nm band has been partially characterized. The rate of the removal of the lower laser level by collision-induced dissociation has been calculated, and the importance of this process emphasized.

Laser action of HgCl* was observed using an electron-beam-controlled discharge to pump a gas mixture of Hg/Cl2/Ar. An order of magnitude in the fluorescence enhancement was obtained. This gives an excitation efficiency by controlled discharge to be a factor of about 2 higher than that by direct electron-beam pumping. In addition to the previously reported 5576-Å laser transition of HgCl*, a strong transition at 5584 Å was also observed.