Influence of admixtures on the gain of a gasdynamic carbon dioxide laser

A shock tube with an internal diameter of 500 mm and a planar 30° nozzle at one end was used in a study of the influence of O₂, H₂, CO, H₂O, C₂H₂, and C₂H₄ admixtures on the gain of a 15% CO₂+83% N₂+2% H₂O gasdynamic laser. The pressure of the active mixture in the entry plane of the nozzle was 5.3 atm and its temperature was 1790°K. it was found that the addition of diatomic molecules in amounts up to 10–14% had little influence on the measured gain. Polyatomic molecules had a stronger influence (they reduced the gain) but throughout the investigated range of the admixtures (up to 16%) the gain was still positive.