Mercury Bromide Laser Research.

This report summarizes major effort to build a discharge tube and associated apparatus capable of withstanding temperatures to 300 C and pressure to 150 psia, and to parameterize the HgBr laser fluorescence and laser output with respect to nitrogen and Ne buffer gas densities. Prior parameterization has been limited to buffer gas densities of about 1.3 Amagat since the laser tube was made Pyrex and therefore could not sustain more than about 15 psi internal over pressure. By enclosing the Pyrex laser tube inside a stainless steel pressure vessel, we have overcome this pressure limitation by maintaining a positive external pressure upon the laser tube. The steel tank was pressurized with nitrogen to avoid oxidation of the tube connections. Thus, the discharge tube, by being enclosed in a nitrogen protective atmosphere, withstands both the high temperature operation and the high internal operating pressures. Fluorescence, laser output, voltage and current waveforms were taken at various nitrogen fill pressures up to 300 Torr with Ne buffer gas densities up to 5 Amagat. For our experimental tube, the HgBr laser output and fluorescence efficiency was maximum at a nitrogen fill pressure of 150 Torr and increased with neon buffer gas density up to the maximum tested of 5 Amagat at a reservoir temperature of about 150 C. Author