Plasma Physics Seminar
Monday, September 30
1610 Engineering Hall
Speaker: Dr. Ian Parrish, Canadian Institute for Theoretical Astrophysics
"Extended Heating in the Solar Wind: The Role of MHD Turbulence and Resonance"
Abstract: The solar wind is an incredibly well-diagnosed collisionless plasma that exhibits a rich set of plasma physics phenomenology. As such, we can learn valuable lessons about other collisionless or anisotropic plasmas, including accretion onto the galactic center black hole, the intracluster medium of galaxy clusters, and even fusion experiments on earth. In this talk, I will focus on the long-standing problem of understanding the extended heating of the solar wind in the context of energy exchange between particles and waves, a ubiquitous theme in plasma physics. On the analytical side, I will discuss several resonant interactions (cyclotron and transit time damping) and Fermi Type-B interactions and the use of quasilinear theory to describe them. On the numerical side, I will focus on the use of test particle MHD as a numerical tool for studying wave-particle interactions. In particular, I will describe the computational method and highlight some of the fun numerical challenges in its development while highlighting its strengths and weaknesses. Finally, I will connect the analytical and numerical pieces to describe some of our results thus far on the heating of the solar wind. I'll also discuss where these results can be augmented by other computational approaches, such as hybrid methods or gyrokinetics, as well as discuss other possible applications of the test particle MHD method including relativistic particles and accretion disk turbulence.