Authors: Collin Brown (University of Iowa), Greg Howes (University of Iowa), Aaron Tran (Columbia University), Kris Klein (University of Arizona)

The process that converts supersonic flow energy into thermal energy in supercritical collisionless shocks differs between ions and electrons and is strongly dependent on the field geometry with respect to the normal of the shock (i.e. shock normal angle), the Mach number of the supersonic flow, and the plasma beta of the system. Shocks with a high enough Mach number will have a sub-population of ions in the system to be reflected in the shock transition region, gaining energy through a process referred to as shock-drift acceleration and also possibly exciting kinetic instabilities that generate waves that can either propagate along the surface of the shock or upstream against the flow and into the precursor depending on the systems parameters. Through wave-particle interactions, these waves may be the cause for the non-adiabatic heating that occurs for electrons as they travel through the shock transition region. We use the “Instability Isolation Method” (Brown et al. 2023) to measure the energy transfer in phase-space between the wave mode excited by particle reflection and the electrons in a fully kinetic 2D3V PIC simulation of a shock that generates super-adiabatic heating of electrons. We compare the signatures of the energy transfer of the isolated mechanism and the particles to the predicted signatures using JET-PLUME (Judging Energy Transfer in Plasmas in a Linear Magnetized Environment), a novel expansion to the linear kinetic dispersion relation solver PLUME that predicts the energy transfer in phase-space using the field-particle correlation technique between a linear wave mode and N bi-Maxwellian drifting species. These techniques are ideal for analyzing the differing heating and energization of reflected ions, non-reflected ions, adiabatic electrons, super-adiabatic electrons, and sub-adiabatic electrons as we can distinguish the differing energy between subpopulations due to a selected wave mode by distinguishing the energization of these populations in phase-space.