SHINE: Instabilities Driven by Anisotropic Ion and Electron Beams in the Solar Wind: Analytical Theory, Numerical Simulations, and In-Situ Observations

University Of New Hampshire, Durham NH

Investigators

Abstract

This 3-year SHINE project aims to apply a fundamental approach to tackle plasma instabilities driven by anisotropic ion and electron beams in the solar wind, and to improve our understanding of micro-instabilities in general. The project will combine the analysis of linear and nonlinear effects, and create a multidisciplinary collaboration among experts in theory, numerical simulation, and observation, with relevance to many plasma systems. The research project will support two young researchers in early phases of their careers and one undergraduate student. The project team will engage local schools within the University of New Hampshire's Upward Bound program, which is designed to help high-school students from low-income families and/or first-generation potential college students succeed in higher education. This activity will provide the students with a unique opportunity to explore the field of space science. The research and EPO agenda of this project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research. This SHINE project involves an integrated and multidisciplinary four-step research program to elucidate the interplay between anisotropies and beams in the distribution functions of both ions and electrons in the solar wind by means of analytical theory, numerical studies, and in-situ observations. The project team will formulate a generalized theory for the instability thresholds of anisotropic and beamed ions and electrons in the solar wind by building on previously developed methods. Numerical solutions of the hot-plasma dispersion relation will allow the project team to verify the analytical findings. The project activities will include hybrid simulations to investigate the nonlinear evolution of the ion instabilities. In the case of electron-driven instabilities, a full particle-in-cell code will help the team investigate the nonlinear evolution of the plasma and the excited waves. The theoretical and numerical results from this project will be compared with observations of plasma and wave properties in the solar wind. The project efforts will be focused on answering the following key scientific question: what determines the thresholds and nonlinear evolution of instabilities driven by anisotropic ion and electron beams in the solar wind? The answer to this question is of paramount interest to the heliophysics community, since physics-driven solar-wind models critically depend on a detailed understanding of the relevant microphysical processes that regulate non-thermal features in the ion and electron distribution functions.