  We present an overview of the performance of the Neutralized Drift
Compression Experiment-II (NDCX-II) accelerator at Berkeley Lab, and summarize
recent studies of material properties created with nanosecond and
millimeter-scale ion beam pulses. The scientific topics being explored include
the dynamics of ion induced damage in materials, materials synthesis far from
equilibrium, warm dense matter and intense beam-plasma physics. We summarize
the improved accelerator performance, diagnostics and results of beam-induced
irradiation of thin samples of, e.g., tin and silicon. Bunches with over
3x10^10 ions, 1- mm radius, and 2-30 ns FWHM duration have been created. To
achieve these short pulse durations and mm-scale focal spot radii, the 1.2 MeV
He+ ion beam is neutralized in a drift compression section which removes the
space charge defocusing effect during final compression and focusing.
Quantitative comparison of detailed particle-in-cell simulations with the
experiment play an important role in optimizing accelerator performance; these
keep pace with the accelerator repetition rate of ~1/minute.
