The Modifications of Collisionless Plasma Shock Hydrodynamics by Non-Thermal Particles in Kinetic Simulations
Abstract
Earth's bow shock, and collisionless plasma shocks more generally, are efficient accelerators of energetic, non-thermal particles, which can affect local space weather conditions and pose a potential threat to manned and unmanned space missions. Shocks can deposit a significant fraction of their ram energy into non-thermal populations, yet despite this, much of our understanding of shock hydrodynamics is derived assuming the plasma is a thermal fluid. With this in mind, we present a theory of modified shock hydrodynamics including the effects of both the self generated, non-thermal, energetic population and the associated enhanced magnetic fields, amplified by the non-thermal particles. Using hybrid simulations of parallel collisionless shocks for a range of Mach numbers, we show that the non-thermal particles diffuse away from the shock in the downstream at an enhanced rate, increasing the compressibility and decreasing the speed of the shock. These hydrodynamic modifications have important implications for our understanding of heliospheric shocks and how the sun and solar wind affect Earth's magnetosphere.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMSH047..01H
- Keywords:
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- 7829 Kinetic waves and instabilities;
- SPACE PLASMA PHYSICS;
- 7845 Particle acceleration;
- SPACE PLASMA PHYSICS;
- 7846 Plasma energization;
- SPACE PLASMA PHYSICS;
- 7851 Shock waves;
- SPACE PLASMA PHYSICS