Gasdynamic laser with a high water vapor content

A shock-tube investigation was made of a gasdynamic CO₂–H₂O–N₂ laser. The gas mixture escaped through a slit. A probing beam, produced by a separate electricdischarge CO₂ laser, was used to study the gasdynamic laser. The parameters of the gaseous mixture, heated by a reflected shock wave, were T₅ = 1300–2250°K and p₅=5–88 atm. The main task was to establish whether population inversion could be achieved in the case of high water content in the active mixture of the gasdynamic laser when the [H₂O] concentration was comparable with the [CO₂] concentration. Gain was observed right up to [H₂O]/ [CO₂] = 1 for a mixture with [N₂]/[CO₂]=4 at T₅=2250°K and p₅=22 atm. In this case the maximum gain was observed at a distance of 25 mm from the slit and it amounted to 0.4·10^–2 cm^–1.