A Collective Accelerator as Ion Source and Injector for a Heavy-Ion Cyclotron

Abstract

Experiments at several laboratories have demonstrated that collective accelerators can produce short pulses of ions with peak energies of several MeV per nucleon and peak currents in the range of 1 to 103 A. A particularly promising approach is the use of lasers to produce high density plasmas from solids with heavy ions of high charge state, which are then accelerated by collective effects to energies above 1 MeV/nucleon. Such a collective accelerator could be used as a combination of ion source and injector for a heavy-ion cyclotron. The ions, after passage through a stripper foil, would be accelerated in the cyclotron as single pulses, and the number of ions per second would depend on the space-charge focusing limit of the cyclotron and the repetition rate of the collective accelerator. A formula for the space-charge limit of the cyclotron for high instant beam currents is derived, and estimates of the particle intensities that could be expected are presented.