The status of rotational nonequilibrium in HF chemical lasers

Abstract : Because of the complexity of accounting simultaneously for gas dynamics, optics, and chemical kinetics in HF chemical lasers all computer modeling codes have simplified drastically at least one of these factors. One way to simplify the details of state to state chemistry is to ignore the possibility of rotational nonequilibrium. Rotational nonequilibrium can affect laser power and energy output, time to onset and duration of lasing, and power spectral distribution. This report will review, in turn, evidence for rotational nonequilibrium in HF chemical lasers; processes that can lead to rotational nonequilibrium in HF lasers; rotational relaxation of HF; and modeling studies of rotational nonequilibrium effects in HF chemical lasers. Keywords: Chemical lasers; Hydrogen fluoride; Energy transfer; Rotational relaxation; and Rotational energy transfer.