Characteristics of the gain medium for an ejector COIL with supersonic nozzles for the driver buffer gas

The use of supersonic nozzles for the driver nitrogen in an ejector nozzle bank (ENB) for chemical-oxygen iodine laser (COIL) resulted in the elimination of the chocking effect for the primary oxygen flow and formation of a low temperature gain medium. The ENB generates a supersonic gain medium with a Mach number greater than 2.2, and a temperature less than 200 K. The potential recovered pressure was 90 Torr with a small signal gain greater than 10(-2) cm(-1). With a 5 cm gain length for this nozzle, the output power was 1.2 kW with a chemical efficiency of 23.4%. A strong decay of I(P-2(1/2)) emission, (concentration), along the gain medium flow was observed .