Plasma Physics (Physics/ECE/NE 922) Seminars
Events on Monday, November 30th, 2015
- MHD SIMULATIONS IN DEVICES WITH COMPLEX 3D BOUNDARIES: THE PSI-TET CODE AND ITS APPLICATION
- Time: 12:00 pm
- Place: 2241 Physics Bldg
- Speaker: Christopher Hansen, University of Washington
- Abstract: In MagnetoHydroDynamic (MHD) simulations of Magnetic Confinement Fusion (MCF) experiments the first wall is often treated as a continuous, symmetric surface. However, even in machines with a high degree of plasma symmetry, the true first wall is complex. Perforations required for diagnostic, heating, and current injection ports and localized stabilizing plates all effect induced-currents in the wall, modifying the behavior of resistive wall modes and scrape-off layer currents.
The PSI-Tet code is a new 3D extended MHD code based on an unstructured tetrahedral grid that allows arbitrary device geometry to be captured. This code employs a high order finite element method using a novel discretization for magnetic flux based on Nedelec basis functions. A fully implicit centered time advance (Crank-Nicolson) is used and solved with a multigrid preconditioned Newton-Krylov method. In this talk progress and results will be presented from two applications of PSI-Tet: 1) Detailed validation studies of the HIT-SI experiment with self-consistent modeling of plasma dynamics in the helicity injectors. Results will be compared to experimental data and NIMROD simulations that model the effect of the helicity injectors through boundary conditions on an axisymmetric domain. 2) Simulations of external kink dynamics in the HBT-EP experiment with different wall configurations, focusing on toroidal asymmetries in the adjustable conducting wall. A brief description of the PSI-Tet code will also be presented focusing on unique features of the code.