The large electric fields associated with sources of space charge have led to numerous proposals for possible collective (space-charge-based) accelerators. Traditionally, these schemes involve either magnetic fields or background ions (a plasma) to contain the space charge. This Letter proposes a new technique for particle acceleration that directly uses the large space charge fields of freely moving electron beams. Such free electron accelerators promise eventual accelerating gradients in excess of 10 GV/m.

• Received 19 January 1993

DOI:https://doi.org/10.1103/PhysRevLett.71.851