Bremen 2017 – wissenschaftliches Programm
P 5.1: Poster
Montag, 13. März 2017, 16:30–18:30, HS Foyer
Validation of current profile diagnostics at ASDEX Upgrade — •Marvin Erdmann1,2, Alexander Bock1, Rainer Fischer1, Valentin Igochine1, Alexander Mlynek1, Matthias Reich1, David Rittich1, Jörg Stober1, and the ASDEX Upgrade Team1 — 1Max-Planck-Institut für Plasmaphysik, Garching, Germany — 2Ludwig-Maximilians-Universität München, Munich, Germany
In magnetic confinement fusion, a hot plasma is confined by a magnetic field. This field balances the plasma's kinetic pressure, forming a so-called magnetic equilibrium. In the tokamak ASDEX Upgrade, the profile of the toroidal current and the related poloidal magnetic field are measured by polarimetry of a plasma-induced Faraday rotation of a DCN laser beam and by polarimetry of the Motional Stark Effect-induced polarization of the neutral beam emissions. Both diagnostics provide constraints for the equilibrium reconstruction but also suffer from calibration and background issues.
The goal of this contribution is to examine the accuracy of the equlibrium reconstruction and the agreement of the two diagnostics with the localization of Neoclassical Tearing Modes (NTMs) occuring exclusively on rational magnetic surfaces. The techniques of localizing NTMs and the validation of the two polarimetry diagnostics will be shown. Candidates for systematic uncertainties will be discussed.