V-I characteristics of a plane disc probe in collisionless streaming plasmas

Abstract

Expansion of high-temperature high-density plasmas produced by focussing high-power lasers on solid targets gives rise to collisionless streaming plasmas with flow velocity U such that C_i «UC_e, where C_e and C_i are electron and ion thermal velocities, respectively. Dimensionless V-I characteristics of a plane disc probe in such streaming plasmas are obtained. The characteristics show a nonsaturation behavior of the probe current in the electron attracting region of the probe operation. It is observed that in the electron repelling region, the slope of the V-I characteristics increases with the decrease in the probe potential.