Early Commissioning Results of the NDCX-II Accelerator Facility*

The Neutralized Drift Compression Experiment-II (NDCX-II) will generate ion beam pulses for studies of Warm Dense Matter science and heavy-ion-driven Inertial Fusion Energy. The machine accelerates 20-50 nC of Li+ to 1.2-3 MeV energy, starting from a 10.9-cm alumino-silicate ion source. At the end of the accelerator the ions are focused to a sub-mm spot size onto a thin foil (planar) target. The pulse duration is compressed from $\sim $500 ns at the source to sub-ns at the target following beam transport in a neutralizing plasma. We report on the results of early commissioning studies that characterize beam quality and beam transport, acceleration waveform shaping and beam current evolution. We present measurements of time-resolved beam phase space density and variation in transverse beam centroid position. We present simulation results to benchmark against the experimental measurements, and to predict performance in subsequent sections of the accelerator.