Extension of the SpK Atomic Physics Code to Generate Global Equation of State Data
Abstract
Global microphysics models are required for the modelling of highenergydensity physics (HEDP) experiments, the improvement of which are critical to the path to inertial fusion energy. This work presents further developments to the atomic and microphysics code, SpK, part of the numerical modelling suite of Imperial College London and First Light Fusion. We extend the capabilities of SpK to allow the calculation of the equation of state (EoS). The detailed configuration accounting calculations are interpolated into finitetemperature ThomasFermi calculations at high coupling to form the electronic component of the model. The Cowan model provides the ionic contribution, modified to approximate the physics of diatomic molecular dissociation. By utilising bonding corrections and performing a Maxwell construction, SpK captures the EoS from states ranging from the zeropressure solid, through the liquidvapour coexistence region and into plasma states. This global approach offers the benefit of capturing electronic shell structure over large regions of parameter space, building highlyresolved tables in minutes on a simple desktop. We present shock Hugoniot and offHugoniot calculations for a number of materials, comparing SpK to other models and experimental data. We also apply EoS and opacity data generated by SpK in integrated simulations of indirectlydriven capsule implosions, highlighting physical sensitivities to the choice of EoS models.
 Publication:

arXiv eprints
 Pub Date:
 May 2024
 DOI:
 10.48550/arXiv.2405.13814
 arXiv:
 arXiv:2405.13814
 Bibcode:
 2024arXiv240513814F
 Keywords:

 Physics  Plasma Physics;
 Condensed Matter  Materials Science;
 Condensed Matter  Statistical Mechanics;
 Physics  Atomic Physics;
 Physics  Computational Physics
 EPrint:
 23 pages (14 of content), 13 figures, 2 tables, submitted for inclusion in the IFSA 2023 conference proceedings