Theoretical considerations of the collective ion acceleration studies at the University of Maryland

This paper presents a model and some specific results on the phenomena of collective ion acceleration (CIA) in linear beam-evacuated drift tube systems. The ion source in this CIA system is an initially localized neutral gas cloud near the electron beam injection end of the drift tube. The model delineates four stages of evolution; virtual cathode formation, ion cloud accumulation, ion-electron cloud separation, and subsequent ion acceleration. Specific results concerning virtual cathode formation and ion-electron cloud separation are presented.