Beam Compression in Heavy-Ion Induction Linacs

The Heavy-Ion Fusion Sciences Virtual National Laboratory is pursuing an approach to target heating experiments in the Warm Dense Matter regime, using space-charge-dominated ion beams that are simultaneously longitudinally bunched and transversely focused. Longitudinal beam compression by large factors has been demonstrated in the LBNL Neutralized Drift Compression Experiment (NDCX) experiment with controlled ramps and forced neutralization. The achieved peak beam current and energy can be used in experiments to heat targets and create warm dense matter. Using an injected 30 mA K+ ion beam with initial kinetic energy 0.3 MeV, axial compression leading to ∼50x current amplification and simultaneous radial focusing to beam radii of a few mm have led to encouraging energy deposition approaching the intensities required for eV-range target heating experiments. We discuss experiments that are under development to reach the necessary higher beam intensities and the associated beam diagnostics