Effects of Element Abundance on Temperature and Charged State Distribution in Laboratory Photoionized Plasmas

The matter in many astrophysical systems can be described as a photoionized plasma. These plasmas consist of multiple elements but are mostly hydrogen dominated. Despite their small concentrations, heavier elements play a dominant role in the physics of these systems and are not well understood. We present experimental and simulation results for neon-hydrogen mixed laboratory photoionized plasmas in which we survey the effects of changing neon abundance on the electron temperature and charged state distribution. The results suggest that the temperature is strongly coupled to neon abundance. The experiments were performed on the Z Machine at Sandia National Labs where a cell filled with neon-hydrogen gas was driven by the x-ray flux produced by a wire array z-pinch implosion. X-ray transmission spectroscopy was used to measure the charged state distribution and electron temperature. The simulations were performed using HELIOS-CR, a 1D radiation-hydrodynamics code with inline atomic kinetics.