Some methods for producing population inversion in the vibrational levels of the H2O molecule

Several methods for producing population inversion in the vibrational levels of the H2O molecule during rapid cooling of H2O-H2 and H2O-OH mixtures in supersonic nozzles are analyzed. The method of rapid cooling of preheated water vapor in supersonic nozzles is found to be the most promising method from the point of view of achieving maximum specific output energy in the far infrared (at a wavelength of 28 or 33 microns). In addition, the nonresonance transfer of energy from excited molecular hydrogen to asymmetric oscillations of the H2O molecule is found to be promising for achieving intense fluxes of coherent radiation in the submillimeter range.