"Laser snow" in the active medium of an XeCl laser

Scattering of λ=0.63-μ probe radiation was found to occur during the operation of an XeCl laser. The results are reported of investigations of the scattering of probe radiation and of changes in the ultraviolet absorption coefficient occurring in the active medium of an XeCl laser excited by an electron beam pulsed at a repetition frequency of 0.2 Hz. It is assumed that the scattering is caused by microscopic particles which are XeCl₂ molecules formed by chemical radiative collisions of Xe atoms with Cl₂ molecules that accumulate during the operation of the laser and cause absorption at the operating wavelength. A discussion is given of the influence of these processes on the energy characteristics and operating lifetime of the laser.