Photoionized plasma experiments at NIF driven by a 12ns long x-ray drive

A new experimental platform has been established at the National Ignition Facility (NIF) in which a plastic-tamped iron-magnesium sample is driven by two gold-halfraum x-ray sources characterized by a bright and broadband x-ray flux with a radiation temperature of 185eV for 12ns. The x-ray flux produces and sustains a photoionized plasma populated with magnesium K-shell and iron L-shell ions. The suite of diagnostics includes DANTE to monitor the performance and duration of the x-ray radiation drive, gated x-ray imaging to observe the expansion of the photoionized iron-magnesium plasma for diagnosing the plasma density, and 2 OpSpec x-ray spectrometers each equipped with 2 elliptically bent KAP crystals to record self-emission and transmission spectra from iron and magnesium ions to characterize charge state distribution, temperature, and plasma emissivity and opacity. We discuss the measurements obtained in two experimental campaigns performed at the NIF, data interpretation and analysis, and the application of the data to benchmark astrophysical models and codes employed in the analysis of x-ray astronomy observations.



This work is supported by DOE NNSA grant DE-NA0004038, the NIF Discovery Science Program, and the LLNL Contract No. DE-AC52-07NA27344