Turbulent Dissipation in Simple Vlasov Simulations*

In this talk, we step back from the grander challenge of elucidating the entire dynamics and thermodynamics of a magnetized, weakly collisional plasma and instead focus on a few simple systems where the solution of how dissipation occurs has an analytic result in certain limits. Our goal is to 1) demonstrate that said analytic result does indeed hold upon simulation, and 2) extend the result marginally beyond the analytic solution with the use of simulations. In particular, we consider a driven Vlasov system of Langmuir turbulence, as well as the turbulence downstream of a transverse electromagnetic shock. With the use of the Gkeyll framework, which contains both a Vlasov-Maxwell solver as well as a simplified Fokker-Planck operator, the Lenard-Bernstein operator, for self-collisions, we can model the fully driven system with both energy injection via the fields, and energy dissipation via the collision operator. The inclusion of the collision operator is in fact key for not just a philosophical, but also a physical understanding of the processes at play, as a collision operator allows one to balance the power input and dissipated to form a phase space cascade in real and velocity space.