HALOGEN HYDRIDE LASERS WITH VIBRATIONAL ENERGY TRANSFER FROM METASTABLE DIATOMIC MOLECULES.

The possibiliy of obtaining efficient coherent emission due to vibrational-rotational transitions in the halogen hydrides HF, DF, HCl, DCl, HBr, and DBr during vibrational energy transfer from slowly relaxing (metastable) diatomic molecules of H//2, HD, D//2, N//2, and CO is demonstrated theoretically. It is proposed that the metastable molecules be excited by electrical preionization. A detailed analysis is made of an H//2 plus HF plus Ar system and the influence of the main factors determining the laser efficiency is identified: radiation spectrum (number of rotational sublevel J), initial gas temperature, proportions of the components, and specific energy input. An estimate is made of the opimal value of e/P ( similar 3V multiplied by (times) cm** minus **1 multiplied by (times) Torr** minus **1). It is concluded that under optimal conditions the efficiency of these lasers may reach 40-50% for H//2 plus HF, HD plus HCl, and D//2 plus HBr systems, and 50-70% for N//2 plus DBr and CO plus DBr systems without the active medium being cooled.