Plasma VIP Seminar

Dr. Bogdan Teaca, Coventry University

"Turbulence in strongly magnetized plasmas: what can we say about its fundamental properties and what are their impact?"

4:00pm, RLM 11.204

Abstract: The analysis of turbulence in weakly collisional plasmas requires a kinetic approach as the relevant dynamics occur between phase space structures in the particles' distribution functions. For strongly magnetized plasmas, the gyrokinetic (GK) formalism represents an appropriate kinetic representation of the turbulence problem, being able to capture the kinetic Alfvén wave cascade, the entropy cascade in the perpendicular direction, as well as the parallel phase mixing associated with Landau damping. Using large resolution numerical simulations spanning an interval ranging from the end of the fluid scales to the electron gyroradius, we investigate GK turbulence for a proton-electron plasma in a slab magnetic geometry. We study the free energy cascade in the perpendicular direction and address its scale locality and universality nature. Furthermore, by measuring the intermittency of the distribution functions, accounting for velocity space structures and correlations generated by linear (parallel) and nonlinear (perpendicular) phase mixing, we explain the preferred route to heating for each plasma species. Last, we talk about the impact of the results found on sub-grid modeling techniques and the complications present in the case of a tokamak magnetic geometry.