The rate by which particles, momentum, and kinetic energy are transferred in collisions is considered for charge carriers with displaced Maxwellian velocity distributions. The collision integrals are expanded in power series of the average momentum and exact expressions are obtained for the general term of the series. The following scattering processes are considered: deformation potential and piezoelectric coupling to acoustical phonons, polar and nonpolar coupling to optical phonons, intervalley scattering, equivalent valley scattering, ionized impurity scattering, and electron‐hole scattering. Exact analytic summation of the series is possible for some processes. It is shown that, to second order in the average momentum, the loss of particles and energy (but not momentum) depends only on the average kinetic energy of the carriers, and not on how the energy is distributed among thermal and drift energy. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
