  Strong collisional shocks in multi-ion plasmas are featured in many
high-energy-density environments, including Inertial Confinement Fusion (ICF)
implosions. However, their basic structure and its dependence on key parameters
(e.g., the Mach number and the plasma ion composition) are poorly understood,
and controversies in that regard remain in the literature. Using a
high-fidelity Vlasov-Fokker-Planck code, iFP, and direct comparisons to
multi-ion hydrodynamic simulations and semi-analytic predictions, we critically
examine steady-state planar shocks in D-3He plasmas and put forward a
resolution to these controversies.
