A STUDY OF STRIPPED PINCHED-BEAM TRANSPORT FOR HEAVY-ION FUSION

One of the alternative scenarios for a heavy ion driver for inertial c onfinement fusion is final transport as a self-magnetic pinch. A beam is stripped by passing it through a thin foil (or gas) which also supp lies neutralizing electrons. The beam is then centered in a long condu cting pipe which may be surrounded by a solenoid to help the confineme nt of neutralizing electrons. Additional electrons are supplied by ion ization of a low pressure gas in the pipe. Immediately before the stri pping foil a mini final focusing system would be applied, which makes the envelope waist of a few millimetre radius at the foil. In this sch eme, the usual chromatic aberration constraint on the heavy ion fusion driver can be relaxed by at least an order of magnitude, which gives substantial relief on the longitudinal beam dynamics issues. A simulat ion study has been performed using an (r,z) particle-in-cell code for all six electromagnetic field components and the three components of p article velocity.