Linear Transient Response of a Plasma to a Pulsed Electric Field

Abstract

The authors have obtained a transient solution of Boltzmann's transfer equation for electrons in a plasma, subjected to a weak pulsed electric field, and used this solution to derive an expression for the transient current density. Explicit expressions for the current density and energy absorbed (during the pulse) have been given when (i) the pulsed field is dc or sinusoidal in nature and (ii) the electron collision frequency is proportional to vs (s=0, 1, 2) (v being the electron velocity). It is seen that the nature of velocity dependence of collision frequency (viz., the value of s) has little effect on the attainment of steady state. The present theory (i) neglects the collective plasma phenomena, which is valid when the frequency of the field is appreciably different from the plasma frequency, (ii) ignores electron-ion and electron-electron collisions, which is valid for weakly ionized plasmas, (iii) ignores nonlinear effects, and (iv) neglects the effects of ion motion (which is appreciable only for highly ionized plasmas and very low frequencies of the field).