Bremsstrahlung statistics. I

The evolution of the bremsstrahlung density matrix is considered for scattering of a nonrelativistic electron beam by randomly distributed potentials. A system of equations for the first two moments of the density matrix is considered in the weak nonlinearity approximation, and solutions are given for coherent initial photon statistics.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 92–97, November, 1978.