A technique is proposed for extracting the beam from the modified betatron accelerator. Briefly, after the acceleration is completed, the beam is forced to drift vertically by applying a rapidly rising toroidal electric field. Following the crossing of the septum, the beam enters the extractor, which is either helical or straight. In the latter case the electrons are guided to target by a plasma lens.

• Received 21 December 1994

DOI:https://doi.org/10.1103/PhysRevLett.74.4851