Formation of a Non-Neutral Relativistic-Electron-Beam Ring in a Toroidal Magnetic Field

Abstract
A quiescent equilibrium state of a non-neutral beam ring may have been realized when a relativistic electron beam (450 keV, 16 kA, 25 nsec) was injected parallel to a toroidal magnetic field in vacuum. The longest lifetime obtained was 20 μsec which corresponded to 3000 revolutions of the electrons around the torus. The lifetime was limited by the appearance of an ion-resonance instability.