Space charge waves in solids

The conventional boltzmann-vlasov equations are solved for the case of a hot plasma with collisions such as may correspond to the conduction electrons in a semiconductor. A collision term is used which contains two relaxation times corresponding approximately to the usual momentum and energy relaxation times. This collision term is so constructed that it does not give rise to a spurious generation of particles by collisions. A general dispersion relation is obtained for space charge waves propagating in such a plasma. In the limit of a cold plasma this dispersion relaxation reduces to results familiar from cold plasma theory.