Quantum-mechanical calculation of ionization potential lowering in dense plasmas
Sang-Kil Son, Robert Thiele, Zoltan Jurek, Beata Ziaja, and Robin Santra
Radiative Properties of Hot Dense Matter
(Vienna, Austria, September 29-October 3, 2014) [oral presentation]
The charged environment within a dense plasma leads to the phenomenon of ionization-potential depression (IPD) for ions embedded in the plasma. Accurate predictions of the IPD effect are of crucial importance for modeling atomic processes occurring within dense plasmas. Several theoretical models have been developed to describe the IPD effect, with frequently discrepant predictions. Only recently, first experiments on IPD in Al plasma have been performed with an x-ray free-electron laser, where their results were found to be in disagreement with the widely used IPD model by Stewart and Pyatt. Another experiment on Al, at the Orion laser, showed disagreement with the model by Ecker and Kröll. In this talk, I will present a rigorous and computationally efficient approach to predicting IPDs: a two-step Hartree-Fock-Slater model. Our approach is based on first-principle quantum-mechanical calculations for an atom embedded in a dense plasma, taking into account detailed electronic configurations of plasma ions. I will demonstrate that, in contrast to the Stewart-Pyatt and Ecker-Kröll models, our model successfully describes all available experimental data on IPDs. Calculations within our approach are relatively inexpensive and, therefore, are expected to be applicable for a wide range of plasma conditions, including warm dense matter, planetary science, and inertial confinement fusion.
ionization potential depression,
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