Linear Collective Effect Acceleration in the Presence of a Strong Axial Magnetic Field

In experimental investigations injecting an intense, relativistic electron beam into low pressure neutral gases, collective ion acceleration was observed to occur even in the presence of an applied axial magnetic field. In these studies using a 2 MeV, 15 kA, 50 nsec electron beam, collectively accelerated protons and deuterons were detected with or without the applied field although yields were diminished two orders of magnitude with an external field of 7.8 kG. It is suggested that formation and collapse of a deep, potential well (virtual cathode) is responsible for the acceleration, and application of the magnetic field just renders the potential well "one-sided".