Beyond Brazil: Numerical Tools for Studying Waves and Instabilities in non-Maxwellian Plasmas*

Weakly collisional plasmas, including the solar wind, are frequently not in local thermodynamic equilibrium, exhibiting a variety of structures such as anisotropies, beams, and non-Maxwellian features. These structures impact the linear plasma response in ways not accounted for in simple Maxwellian models. We present an overview of recent results using three numerical tools for discerning non-Maxwellian plasma behavior in numerical simulations and spacecraft observations.

These tools include:

-PLUME (Plasma in a Uniform Linear Magnetized Environment), which calculates the linear response for an arbitrary number of relatively drifting bi-Maxwellian plasma components,

-SAVIC (Stability Analysis Vitalizing Instability Classification), a machine learning algorithm for predicting and classifying instabilities, and

-ALPS (Arbitrary Linear Plasma Solver), an open-source code for numerically integrating the particle phase space density rather than modeling the distribution as a sum of bi-Maxwellians.

These tools enable the study of the impact of non-Maxwellian structure beyond the simpler parametric models that have been historically applied to solar wind studies.