Collective Ion Acceleration in a Converging Wave Guide

Abstract

An ion-acceleration mechanism is proposed in which ions are trapped and accelerated by a negative-energy space-charge wave. Under certain conditions, an electron beam propagating down a slowly converging metal guide can be accelerated. A low-phase-velocity space-charge wave initiated at the large-radius end of the guide, because it is supported by the beam, will also accelerate. By trapping ions in the potential wells of a low-phase-velocity wave, ion acceleration down the converging drift tube can be achieved.