Seidl, P.A. Barnard, J.J. Feinberg, E. Friedman, A. Gilson, E.P. Grote, D.P. Ji, Q. Kaganovich, I. Ludewigt, B.A. Persaud, A. Schenkel, T. Silverman, M. Stepanov, A.D. Sulyman, A.A. Treffert, F. Waldron, W.L. Zimmer, M. JACoW Geneva, Switzerland 978-3-95450-180-9 10.18429/JACoW-NAPAC2016-WEPOA29 English 755-757 WEPOA29 ion experiment target plasma focusing Contribution to a conference proceedings 2017 2017-01 http://dx.doi.org/10.18429/JACoW-NAPAC2016-WEPOA29 https://jacow.org/napac2016/papers/wepoa29.pdf 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 3x10¹⁰ 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.