Ion Species Stratification Within Strong Shocks in Two-Ion Plasmas

Abstract

Strong collisional shocks in multi-ion plasmas are featured in many environments, with Inertial Confinement Fusion (ICF) experiments being one prominent example. Recent work [Keenan $etal.$, PRE $96$, 053203 (2017)] answered in detail a number of outstanding questions concerning the kinetic structure of steady-state, planar plasma shocks, e.g., the shock width scaling by Mach number, $M$. However, it did not discuss shock-driven ion-species stratification (e.g., relative concentration modification, and temperature separation). These are important effects, since many recent ICF experiments have evaded explanation by standard, single-fluid, radiation-hydrodynamic (rad-hydro) numerical simulations, and shock-driven fuel stratification likely contributes to this discrepancy. Employing the state-of-the-art Vlasov-Fokker-Planck code, iFP, along with multi-ion hydro simulations and semi-analytics, we quantify the ion stratification by planar shocks with arbitrary Mach number and relative species concentration for two-ion plasmas in terms of ion mass and charge ratios. In particular, for strong shocks, we find that the structure of the ion temperature separation has a nearly universal character across ion mass and charge ratios. Additionally, we find that the shock fronts are enriched with the lighter ion species, and the enrichment scales as $M^4$ for $M\gg 1$.

12 pages, 19 figures; submitted to Physics of Plasmas

References in corpus (2)

• Deciphering the Kinetic Structure of Multi-Ion Plasma Shocks
• Simulation and assessment of ion kinetic effects in a direct-drive capsule implosion experiment

Cited by in corpus (10)

• An Eulerian Vlasov-Fokker-Planck Algorithm for Spherical Implosion Simulations of Inertial Confinement Fusion Capsules
• Experimental Measurements of Ion Heating in Collisional Plasma Shocks and Interpenetrating Supersonic Plasma Flows
• An efficient, conservative, time-implicit solver for the fully kinetic arbitrary-species 1D-2V Vlasov-Ampère system
• Favorable Collisional Demixing of Ash and Fuel in Magnetized Inertial Fusion
• Parallel transport modeling of linear divertor simulators with fundamental ion cyclotron heating
• Effect of a weak ion collisionality on the dynamics of kinetic electrostatic shocks
• Observation of Shock-Front Separation in Multi-Ion-Species Collisional Plasma Shocks
• Experimental Measurements of Ion Diffusion Coefficients and Heating in a Multi-Ion-Species Plasma Shock
• Kinetic simulations of collision-less plasmas in open magnetic geometries
• Fully kinetic simulations of strong steady-state collisional planar plasma shocks