|Physics Colloquium - Plasma Flows in Axisymmetric Systems|
|Time: Feb 28, 2014 03:00 PM|
|Location: Parker Hall Room 236 Snacks provided Allison Lab Room 200 @ 2:45pm|
Plasma flows are common in nature and in experimental devices for magnetically confined nuclear fusion. In this talk, the main focus is on nuclear-fusion tokamak experiments, which are described as two-dimensional axisymmetric systems. It is shown that different flow patterns can cause quantitative and qualitative modifications in the properties of tokamak plasmas. Magnetohydrodynamic and two-fluid equilibrium models are introduced and used to study the effect of flow. Particular attention is devoted to the class of so-called transonic equilibria, in which plasma rotation exceeds a characteristic velocity (the poloidal sound speed) at the edge of the plasma and is slow in the plasma core. Discontinuous equilibrium profiles are obtained, justified with an intuitive physical description and confirmed by time-dependent simulations. A possible connection to experimental findings is presented. Additional applications of the study of plasma flows to experiments and astrophysical systems are also briefly introduced.