Non-thermal particle acceleration at highly oblique non-relativistic shocks

TL;DR

This study uses large-scale PIC simulations to investigate how electrons and ions are accelerated at highly oblique, non-relativistic shocks, revealing early diffusive shock acceleration onset and ion acceleration efficiencies.

Contribution

It demonstrates the role of electron pre-heating in particle injection and acceleration at high Mach number shocks using detailed PIC simulations.

Findings

Evidence for early diffusive shock acceleration onset.

Ion acceleration efficiencies of up to 5%.

Electron and ion acceleration observed at highly oblique shocks.

Abstract

The non-thermal acceleration of electrons and ions at an oblique, non-relativistic shock is studied using large scale particle-in-cell (PIC) simulations in one spatial dimension. Physical parameters are selected to highlight the role of electron pre-heating in injection and subsequent acceleration of particles at high Mach number shocks. Simulation results show evidence for the early onset of the diffusive shock acceleration process for both electrons and ions at a highly oblique subluminal shock. Ion acceleration efficiencies of $\lesssim 5\%$ are measured at late times, though this is not the saturated value.