Penetration to second order of an electrostatic field into a warm plasma

Abstract

Using a reformulation of ordinary perturbation theory to first and second order, explicit solutions for the penetration of electrostatic waves into a semi-infinite Vlasov plasma are presented. Two types of electron velocity distribution are used, the uniform step (‘water-bag’ model) and the Maxwellian. The existence of propagating modes below the plasma frequency, behaviour of the second harmonic field and the formation of a narrow sheet of electrons near the bounding wall are displayed. Replacement of boundary fields with equivalent charge and current sources is discussed.