WB6 - DF-CO2transfer laser development

Power extraction and chemiluminescence experiments have been conducted in the large-scale DF-CO
2
transfer chemical laser (TCL) (IRIS-I and IRIS-II) facility at Bell Aerospace Company (BAC). The modular design of the device allowed testing to be conducted with both a supersonic nozzle bank and also in subsonic flow with sonic injection for the deuterium. Power levels of 15 kW at 10.6 μ were obtained in IRIS-I (subsonic) employing an unstable resonator with a 50-percent output coupling ratio and cavity pressure of 35 torr. For IRIS-II (supersonic) somewhat lower power was obtained. In both systems the fluorine dissociation (α = F/F + 2F
2
) was less than 0.01. Chemi-luminescent emission from HF and DF was monitored under zero-power conditions along an axis parallel to the laser-mirror axis. From the measured DF-concentration profiles it can be inferred that vibrationally excited DF is being produced throughout the cavity and, accordingly, the production of DF must be attributed largely to the chain reaction.