  We theoretically investigate stimulated bremsstrahlung emission and
absorption (SBEA) in the scattering of a relativistic electron by a nucleus in
a multifrequency field of circularly polarized plane electromagnetic waves
propagating in the same direction. The general relativistic expression for the
SBEA probability is derived. It is demonstrated that the probability of
multiphoton SBEA involving an arbitrary number of waves is governed by the
functions, which depends on BunkinFedorov quantum parameters and quantum
interference parameters. We separate two substantially different kinematic
ranges in electron scattering: the BunkinFedorov range and the interference
range. In the interference range, we reveal a correlation between the numbers
of photons in all the waves. Due to this correlation, the total number of
photons emitted or absorbed by an electron (with allowance for the
polarizations of waves) is equal to zero. We analyze the cases of
nonrelativistic, relativistic, and ultrarelativistic electron energies. It is
demonstrated that the probability of multiphoton SBEA for an electron scattered
in the interference range may considerably exceed the corresponding probability
in the BunkinFedorov range.
