Modeling Transient Effects in Laboratory Photoionized Plasmas

Measurements of the electron temperature in laboratory photoionized plasma experiments have shown significant discrepancies with predictions computed with astrophysical codes that assume a steady state model². However, simulations of the experiments performed with radiation-hydrodynamics codes have produced good temperature comparisons between theory and observation. For the conditions of the experiments, the heating and temperature of the photoionized plasmas depend primarily on radiative heating and cooling. In turn, the temperature impacts the level population distribution that determines the opacity and emissivity of the plasma. We will discuss the differences in assumptions and approximations used in the physics models employed in the astrophysical and radiation-hydrodynamics modeling codes and how they can impact the prediction of temperature. We report significant improvements in the temperature prediction of astrophysical codes when transient effects are considered.

R. C. Mancini et al, Phys. Rev. E 101, 051201(R) (2020). This work is supported by DOE NNSA NLUF Grant DE-NA0004038.