Theoretical and experimental studies on high-current ion beam acceleration and compensation in an induction linac for inertial confinement fusion

The prototype induction linac under study for space-charge-neutralized beams, comprising an injector and two induction stages with magnetoinsulated cusps in the accelerating gaps, enabled effective postacceleration of the ion beam by an induction electric field. The extracted beam parameters were: 2 kA, 500 keV, 0.5 s. For axially symmetric systems, a new mechanism of ion beam neutralization in the accelerating gap is proposed. Detailed consideration is given for two most dangerous instabilities disturbing effective ion beam transport along the accelerator channel and the drift chamber. The ion beam filamentation was observed in our experiments.