Current multiplication during relativistic electron-beam propagation in plasma

Abstract

During the passage of a highly relativistic electron beam through a plasma, the net current can be greater than the beam current. This current increase can be caused by momentum transferred from the beam to the plasma via the two-stream instability. The current gain at saturation of the two-stream instability is computed, and the theoretical results agree well with a one-dimensional computer simulation of the phenomenon. An equation is derived for the total plasma current, including both the current driven by the two-stream instability and the current driven by the beam-induced electric field.