Longitudinal and transverse instabilities in a high-current modified-betatron electron accelerator

The paper examines a number of potentially destructive instabilities which can arise in a high-current modified-betatron electron accelerator. A dispersion relation is derived, which describes the longitudinal and transverse instabilities on an intense non-neutral electron beam in a modified-betatron field configuration. Limiting regimes of the dispersion relation are discussed with respect to kink instability, and instabilities associated with the azimuthal and transverse beam oscillations. (U.K.)