Transport studies of cusp and multichannel REB fusion concepts

Single-particle trajectory calculations have been used to study the effectiveness of beam concentration near a target pellet in two relativistic electron-beam-driven inertial fusion concepts: magnetic cusps and multiple current-carrying channels in a wagon-wheel configuration. Angular momentum constraints favor the multichannel transport scheme. The role of angular momentum nonconserving reflections from plugged-cusp loss cones is discussed. Minimum radii are calculated for various injection conditions in a 40-channel configuration. The resulting superposition of beams may provide an order-of-magnitude improvement in beam concentration over single-beam results.