Kinetic Phase-Space Dynamics of Sculpted Ultracold Plasmas: Open questions for kinetic and hydrodynamic models

The inherently integrated nature of ICF and HEDP experiments makes validating important underlying microphysics models challenging. Simpler experiments that isolate and test individual microphysical processes in similar parametric regimes can allow a more complete picture of transport in HEDPs.In this talk, I will discuss an ultracold neutral plasma experimental platform that reproduces conditions in HEDP-like plasma coupling regimes. This platform enables careful isolation of kinetic microphysical processes that we characterize by measuring the time-evolving ion distribution functions, providing a rare opportunity for detailed computational and theoretical tests of kinetic effects in complex plasmas. Comparisons between the experiment and simulations reveal assumptions used in the kinetic approximations, such as velocity-integrated cross-sections, "collisionless" collision operators, and frequency-independent ion interactions, as well as basic treatments of collective effects and thermalization. I will give an overview of ultracold plasmas, their similarity to HEDP systems, and how we prepare them using sculpted initial conditions. I will also present detailed comparisons between measured and simulated phase-space evolution in initially far-from-equilibrium plasmas and highlight opportunities for higher-fidelity models.