Ion kinetic dynamics in strongly-shocked plasmas relevant to ICF

Implosions of thin-shell capsules produce strongly-shocked (M > 10), low-density (rho similar to 1 mg cc(-1)), high-temperature (T-i similar to keV) plasmas, comparable to those produced in the strongly-shocked DT-vapor in inertial confinement fusion (ICF) experiments. A series of thin-glass targets filled with mixtures of deuterium and Helium-3 gas ranging from 7% to 100% deuterium was imploded to investigate the impact of multi-species ion kinetic mechanisms in ICF-relevant plasmas over a wide range of Knudsen numbers (N-K equivalent to lambda(ii)/R). Slightly kinetic implosions (N-K similar to 0.01-0.05) follow the expected yield trend with experimentally-inferred N-K, suggesting effects associated with long mean-free-paths (such as energetic tail-ion loss) provide the dominant yield reduction mechanisms. In contrast, highly kinetic implosions (Rinderknecht et al 2015 Phys. Rev. Lett. 114 025001) with inferred N-K > 0.5 produce the opposite yield trend from the Knudsen-number prediction, confirming the dominance of multi-species physics in these experiments. The impact of the observed kinetic physics mechanisms on the formation of the hotspot in ICF experiments is discussed.