Two-element photoionized plasma experiments at OMEGA EP

A new platform established at the OMEGA EP laser facility in which a tamped sample is driven by a three-Cu halfraum x-ray source that produces a 30ns-duration, broadband x-ray flux with a radiation temperature of 90eV was employed to produce photoionized plasmas in steady state. The x-ray source performance is monitored with VISAR and its spectral distribution is recorded with a grating spectrometer. Plasma density is determined from the expansion measurement performed with an imaging grating instrument and charged state distribution and temperature are extracted from the analysis of K-shell line absorption spectrum recorded with a crystal spectrometer. The latter diagnostic is afforded by using a separate laser beam to drive a short-duration source of backlighting photons. We discuss the observations recorded during several campaigns at OMEGA EP in which two-element silicon-iron and silicon-oxygen photoionized plasmas were produced, and the comparisons with radiation-hydrodynamics and astrophysical modeling codes. This work is supported by DOE HEDLP grant DE-NA0004038, and the NLUF Program.