Investigating Kinetic Instabilities Within the Solar Wind Plasma using Hybrid-Kinetic Particle-in Cell Code

Abstract

Plasmas are extremely important within the context of astrophysics. Specifically, kinetic instabilities have been known to affect thermodynamics of astrophysical plasmas, regulating temperature anisotropy and heating in ways that have not yet been fully modeled. It is in the pursuit of a better understanding of these instabilities that the Solar Wind can prove useful, as it is one of the only astrophysical plasmas that can be measured extensively due to its proximity. In this paper, we report the results of simulations conducted using the hybrid-kinetic PIC code Pegasus of a portion of the solar wind. To recreate the expansion and contraction of the solar wind plasma, we utilize the Hybrid Expanding Box (HEB) model. We measure the time evolution of the plasma stability as well as the changes in energy due to magnetic field fluctuations within the plasma. We find that the instabilities within the simulated solar wind plasma regulate the temperature anisotropy, signifying that the code used is effective in conducting such simulations.