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

摘要

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 Ci ≪U≲Ce, where Ce and Ci 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.