Photoinduced Nucleation of Water Vapor

Strong photoinduced nucleation of pure water vapor was found to occur in a wavelength range where no ultraviolet absorption of water vapor has been reported. Systematic studies were made of the dependence of the nucleation rate and the delay time for the initiation of nucleation on light intensity. The results obtained were accurately fitted by a phenomenological mechanism whereby the nucleation is initiated by clusters accumulating an appropriate number of photoexcited water molecules.