An analysis of the response of an aerosol and of the laser-chemical kinetic
s of a photon-branched chain reaction is used to determine the range of the
maximum permissible parameters of the disperse component capable of suppor
ting the operation of a pulsed chemical HF laser with a two-phase active me
dium (particle radius 0.09-0.4 mu m, particle concentration 10(9)-10(7) cm(
-3)). It is shown that, in this range of parameters, the lifetime of the ac
tive medium of an HF laser with disperse Al particles is governed by coagul
ation, precipitation, and electrostatic scattering of particles, and that i
t amounts to 250 s. The main contribution to the degradation of the dispers
e component of the active medium comes from Brownian coagulation.