On the classification of electron streams

Abstract

The relationships between different types of electron stream may conveniently be studied in terms of three dimensionless characteristic parameters. These are f, the ratio of positive to negative charge in the stream, ν, the product of the number of electrons per unit length in the stream and the classical electron radius (e2/mc2), and defined as (1 - β2)-1/2 - 1, where βc is the drift velocity. With the aid of these parameters a number of typical streams in which f is zero (electron beams in vacuum tubes and accelerators) or unity (neutralized electron beams, Budker's self-constricted beam, pinched gas discharge plasmas) are studied, and relationships between them are illustrated on the log - log ν plane.