Space charge neutralization of high brightness ion beams

Experiments are under way to investigate the extent to which various space charge neutralization methods will allow one to exceed the space charge limited transport condition. Imperfect spatial neutralization will result in nonlinear fields which have the effect of diluting the phase space density of the beam, and thereby increasing the emittance. These experiments give quantitative results on the problem of vacuum neutralization in the final focus/transport for a heavy ion fusion reactor.