ABSTRACT

Plasma streams appear in practice in a number of different contexts. They are basic to various laboratory devices typified by the so-called traveling wave tube or amplifier; and in nature an example which has recently attracted attention is the "solar wind". charged particles of a stream can move with a speed close to that of the wave, and are in consequence under the action of an electric field whose phase at the particle scarcely varies. This can result in the steady conversion of the macroscopic energy of the stream to the field energy of the wave, or vice versa. An allied but somewhat different sequence of events takes place when particles initially accelerated away from some region by the electric field of the wave are returned to it by the streaming motion with a different density.