Relativistic Modeling Capabilities in PERSEUS Extended-MHD Simulation Code for HED Plasmas

A relativistic version of the PERSEUS extended magnetohydrodynamic simulation code for high-energy-density (HED) plasmas is developed and validated. Nonrelativistic PERSEUS solves the two-fluid equations, formulated in terms of a generalized Ohm's law, so as to model about nine orders of magnitude in density variation using a local semi-implicit method. Relativistic PERSEUS preserves this structure and, therefore, retains these advantageous properties, enabling it to model a broader range of relativistic HED phenomena than the existing particle and fluid codes. The relativistic code is validated against a published particle-in-cell (PIC) simulation of the penetration of a laser into a supercritical hydrogen plasma with applications to fast ignition. PERSEUS recovers the penetration ahead of the laser of magnetized relativistic jets. As in the PIC simulation, multiple jets form and subsequently coalesce into larger centralized jets. The relativistic code also recovers expected nonrelativistic results for a problem in which the smallest electron length and time scales are under-resolved, and which is, therefore, inaccessible to PIC codes and conventional (explicit) fluid codes. The code can now be applied to relativistic phenomena with under-resolved electron dynamical scales, e.g., X-pinches and electrode surface plasmas.