Radiative heating and cooling of laboratory photoionized plasmas

Recent measurements of the electron temperature in laboratory photoionized plasma experiments have shown significant discrepancies with predictions computed with astrophysical modeling codes¹. 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 mainly depend on radiative heating and cooling. In turn, the temperature impacts the level population distribution that determines the opacity and emissivity of the plasma. Hence, the electron temperature is a central parameter of photoionized plasmas that depends on external x-ray flux, atomic physics and density. 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 result in different temperature predictions. ¹R. C. Mancini et al, Phys. Rev. E 101, 051201(R) (2020).