High Current Betatron

In the conventional Betatron the problems of electron injection, beam stability during acceleration and beam extraction were solved. The electron current was limited by the method of injection. We propose to inject electrons by the method of inductive charging. This involves a toroidal magnetic field in addition to the normal Betatron fields. It should then be possible to increase the electron current by a factor of 104- 106. The toroidal magnetic field is stabilizing for collective instabilities such as negative mass, but it introduces particle orbit resonances that are absent in a normal Betatron. We show how orbital instabilities can be eliminated. After accelerating the electrons the toroidal magnetic field is no longer necessary to control space charge. It can be allowed to decay so that the beam can be extracted with a conventional magnetic peeler.