Plasma Instabilities in the Young Solar Wind: Thermodynamics far from Equilibrium
Abstract: Characterizing the thermodynamics of the Sun's corona and extended atmosphere is essential to understanding how the young solar wind expands and is accelerated and provides a natural laboratory for studying plasma physics processes that arise throughout the Universe. One key feature of the young solar wind, due to its diffuse and hot nature, is that the collision frequency is low compared to other dynamic timescales, enabling the plasma to maintain significant deviations from local thermodynamic equilibrium. In such weakly collisional systems, these departures can drive unstable wave growth and serve as signatures of wave-particle interactions that act to transfer energy between the charged particles and electromagnetic fields. In this talk, we discuss measurements of non-equilibrium solar wind structure made by spacecraft throughout the inner heliosphere, and the application of mathematical tools to infer what mechanisms, in particular instabilities, may be driven by these structures. Understanding this energy transfer will shed new light on the processes driving solar and stellar winds, heating accretion disks, and stirring the interplanetary and interstellar medium.