Investigating the role of ion kinetic effects on the puzzling High-Z OMEGA campaign capsules

The OMEGA High-Z campaign was a series of OMEGA shots – capsules containing high-Z dopants — conducted in the late 2010s.¹ Simulation efforts have thus far to fully capture the trends noted in the experimental observables (e.g., the fuel compression). Various explanations for these discrepancies have been offered over the years, including ion species separation driven by multi-ion diffusion.² Using the state-of-the-art, multi-ion, Vlasov-Fokker-Planck (VFP) code, iFP,³ we simulate a few High-Z capsules for which ion kinetic effects may be implicated. By comparisons with xRAGE⁴ rad-hydro simulations, we identify the impact of shock-driven ion species density stratification and temperature separation within the doped deuterium fuel – allowing us to further bound the role played by ion kinetic effects on high-Z capsule performance.

¹Dodd et al. Phys. Plasmas 19, 042703 (2012).

²Kyrala et al. LA-UR-11-05535 (2011).

³Taitano et al. J. Comp. Phys. 263, 10786 (2021).

⁴Gittings et al., Comput. Sci. Discovery 1, 015005 (2008).