Probing Extreme Atomic Physics at Petapascal Pressures

Petapascal (~10¹⁵ Pa = 10 Gbar) pressures can be routinely accessible by inertial confinement fusion implosions due to compressions of both shock and spherical convergence. New atomic physics phenomena, such as interspecies radiative transitions,[1] might show up in superdense plasmas under extremely high pressures. A better understanding of such extreme atomic physics can, in turn, help diagnose high-energy-density plasmas. For these purposes, we have initiated a series of combined experimental and theoretical campaigns on OMEGA to examine detailed atomic physics at superhigh pressures using stable Cu-doped CH shell implosions. Time-resolved, high-resolution spectroscopy has been used to simultaneously measure K_a and K_b emission/absorption of Cu in the stagnating shell during the hot-spot formation. These observations have been interpreted by radiation-hydrodynamic simulations coupled with both commonly used collisional-radiative (NLTE) models and our newly developed VERITAS model that is based on density functional theory and multi-band kinetic modeling. We will present quantitative comparisons between experiments and simulations, with the expectation to establish a unified physics picture of how atoms behave in extremely high pressures. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0003856 and US National Science Foundation PHY Grant No. 1802964. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.

 

[1] S. X. Hu et al., Nat. Commun. 11, 1989 (2020).