Material Properties under Extreme Conditions --- Why should we care as ICF scientists?

Suxing Hu, Laboratory for Laser Energetics (LLE)

Hopeman 224

Accurate knowledge of the static, dynamic, and optical properties of high-energy-density (HED) materials is essential for reliably designing inertial confinement fusion (ICF) implosions. In the warm-dense matter regime, routinely accessed by ICF implosions, many-body strong-coupling and electron degeneracy effects play an important role in determining material properties under extreme conditions. First-principles methods for quantum many-body systems, such as path-integral Monte Calro (PIMC) and density functional theory (DFT) developed over the past decades for condense matter physics, material science, and computational chemistry, can provide a self-consistent way to predict properties of HED materials (with systematic improvement possible). DFT-based quantum molecular-dynamics (QMD) has been a working horse for accurate predictions of static, transport, and optical properties of materials under HED conditions, which often give good agreement with experiments (with some exceptions). In recent years, time-dependent DFT started to play a crucial role in studying dynamic and transport physics in HED plasmas/materials. In this talk, I will present: (1) what HED physics we have learned from PIMC and DFT-based QMD calculations; (2) how these first-principles results impact on our understanding of inertial-confinement fusion implosions and HED-physics experiments in general; and (3) what theoretical/computational challenges we are facing to further improve physics predictions of HED materials/plasmas.