  Within the framework of the kinetic method, the process of interaction of a
rarefied electron plasma with laser beat waves is investigated taking into
account the initial spread in the velocities of plasma particles. Using the
expression for the spectral distribution function of plasma particles in the
presence of laser beat waves, an anisotropic tensor of the plasma dielectric
permittivity is obtained. In this case, an expression for the nonequilibrium
current density induced by the perturbed field and the constitutive equation
connecting the conductivity tensor with the dielectric permittivity are
determined. Assuming that in equilibrium the particle distribution function has
the form of the Maxwellian distribution function, the dielectric tensor is
diagonalized. Analytical expressions are obtained for the longitudinal and
transverse components of the dielectric permittivity.
