Stability of a runaway electron beam

Abstract

The paper studies the distribution function of a runaway electron beam with allowance for close collisions of fast tail electrons with thermal ones, as a result of which momentum is imparted to the latter sufficient for escape into a continuous acceleration regime. It is shown that a beam is formed which is not in equilibrium with respect to transverse momenta; it may excite electromagnetic plasma instabilities under the conditions of linear and non-linear electron cyclotron resonance.