Equilibrium and propagation of a rotating relativistic electron beam

An experimental and theoretical study of a charged, but not current‐neutralized, hollow, rotating relativistic electron beam propagating inside a metal tube in the absence of an external magnetic guide field is described. A model has been developed in which the radial equilibrium is derived from the force balance on the beam interacting with its self‐field, and the velocity of propagation of the beam is derived from the power balance. The experimental results show close agreement with the predictions of the model.