Matthias Willensdorfer, Max Planck Institute for Plasma Physiche

Title: 3D dimensional effects in Tokamaks

Abstract:  The application of Resonant Magnetic Perturbations (RMPs) is a promising method for suppressing Edge Localized Modes (ELMs) in ITER. In recent years, there has been significant advances in understanding the impact of RMPs on the plasma edge region. This contribution will present the latest insights gained from comparing state-of-the-art magnetohydrodynamic (MHD) modelling with experimental measurements of RMP effects on the plasma at the ASDEX Upgrade tokamak.  RMPs distort the axisymmetry of the plasma boundary, a phenomenon well-described by ideal MHD, which influences the stability of MHD modes at the edge such as ELMs. Comparisons between experimental observations and the CASTOR3D code identify the underlying physics. In cases where RMP application results in ELM suppression, ideal MHD alone is not sufficient for describing experimental observations. Precise measurements of the distortion reveal local structures, which are attributed to a magnetic island at the top of the pedestal. Comparisons to non-linear resistive MHD calculations provide further confidence. This research addresses a long-standing open question to better understand the physics behind RMP-induced ELM suppression.    

Bio: Matthias Willensdorfer's journey into Fusion science began during his time at Uppsala University, where he worked on a neutron detector for the JET tokamak during an exchange semester. He subsequently earned both his MSc and PhD in Physics from the Technical University of Vienna (TU Wien), focusing his research on particle transport within the plasma edge region of a tokamak plasma.  After completing his PhD, Matthias secured a EUROfusion researcher grant, which enabled him to join the Max-Planck Institute of Plasma Physics. Since then, he has been working on the application of Resonant Magnetic Perturbations on tokamak plasmas. Currently, Matthias serves as a senior scientist at the Max-Planck Institute of Plasma Physics, physics operator of the ASDEX Upgrade tokamak, and member of the ITPA expert group.
 

Please note - there are two Plasma Physics Collloquium talks scheduled on Friday, April 19, 2024 (Matthias Willensdorfer at 10:30 AM in 633 Mudd and Mitchell Walker at 3:00 PM in 825 Mudd). Both talks will be offered in a hybrid format. If you wish to participate remotely in either seminar, please send an email to [email protected].