A technique for determining gas temperature and atomic density such as in CuBr lasers

We have developed a general technique for simultaneously determining in situ both gas temperature and atomic number density of glow-discharge constituents. A theoretical absorption line profile is fitted, by minimizing the least squares, to the measured profile. The ground-state or excited-state density is accurately determined for a wide range of discharge operating conditions and the temperature can be determined within a more restricted range of discharge operating conditions. The technique is most accurate in the same region where absorption is most easily measured, i.e., 5–99% absorption. As an example of its usefulness we have applied this technique to the measured absorption of tunable dye laser radiation in CuBr laser discharges. The temporal variation of both the ground-state Cu density and the gas temperature were determined. In this case the temperature cannot be easily measured by other methods.