Ab initio simulations and measurements of the free-free opacity in aluminum

Journal article

The free-free opacity in dense systems is a property that both tests our fundamental understanding of correlated many-body systems, and is needed to understand the radiative properties of high energy-density plasmas. Despite its importance, predictive calculations of the free-free opacity remain challenging even in the condensed matter phase for simple metals. Here we show how the free-free opacity can be modelled at finite-temperatures via time-dependent density functional theory, and illustrate the importance of including local field corrections, core polarization, and self-energy corrections. Our calculations for ground-state Al are shown to agree well with experimental opacity measurements performed on the Artemis laser facility across a wide range of extreme ultraviolet wavelengths. We extend our calculations across the melt to the warm-dense matter regime, finding good agreement with advanced plasma models based on inverse bremsstrahlung at temperatures above 10 eV.

Authors: Hollebon, P; Ciricosta, O; Desjarlais, MP; Cacho, C; Spindloe, C

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review E
• Volume: 100
• Issue: 4
• Article number: 043207
• Publication date: 2019-10-23
• Acceptance date: 2019-05-22
• DOI: 10.1103/PhysRevE.100.043207
• EISSN: 2470-0053
• ISSN: 2470-0045