Sheet electron beam confinement for rectangular cross-section Cerenkov amplifiers

Summary form only given, as follows. Analyses have been performed which predict that sheet electron beams confined by periodic cusped magnetic (PCM) focusing should be stable against low-frequency breakup instabilities (such as diocotron) provided the magnet period is short enough. Criteria have been identified delimiting a regime of stable, focused sheet beam propagation. Several PCM configurations providing two-plane focusing have been evaluated. An open-sided configuration using offset pole pieces has been found to be preferable in terms of maximum focusing strength, beam entrance matching to minimize emittance spread, and accessibility for input and output RF coupling.