Medium diagnostics for a 10-kW CW HF chemical laser

The supersonic free jets of an arc-driven 10-kW CW HF chemical laser were studied for fixed-flow conditions with and without lasing. A spatially, spectrally, rapidly scanning spectrograph and a spatially scanning stagnation and static pressure probe were used in the diagnosis. The average static temperature and average HF(3) populations were deduced for a very large number of positions in the flow. Salient results include the capability of evaluating the uniformity of reaction in the jet, especially along the cavity axis near the nozzle exit plane, and a qualitative evaluation of the degree of consumption of lasant reactant in the cavity region. A significant local cooling effect resulting from power extraction was observed. Spatial scans of stagnation and static pressures were made for the zero-power case, and Mach numbers and local mass densities were deduced.