Modeling Toolset for Dynamic Resistive-Wall-Mode Discrimination and Feedback Control Design

72753-The Resistive Wall Mode (RWM) is a major instability that limits performance in current and projected future advanced tokamaks. Active control of the RWM using external coils to cancel RWM magnetic flux has been shown effective in stabilizing the mode. The control scheme requires both accurate isolation of the mode flux from the total flux and accurate modeling of system responses to the mode flux. This project will develop a flexible desktop tool to facilitate the calculation of the mutual couplings of the plasma-wall-coil-sensor system in a three-dimensional toroidal geometry that can be easily modified to test different systems. The tool also will facilitate the construction of system-response models for effective RWM detection. In Phase I, a vacuum field code was modified to model the resistive wall and RWM structure as current eigenmodes. The extended code was then designed to calculate the mutual plasma-wall-coil-sensor couplings in a flexible manner, so that alternative geometries can be easily implemented. Phase II will: (1) optimize the RWM identification and control toolset, including the expansion of its functionality for more general use; (2) validate the toolset, including real-time vacuum and plasma tests; and (3) automate the toolset in an experimental facility, and develop packaging materials, including a user¿s guide. Commercial Applications and Other Benefits as described by awardee: The modeling toolset should provide a flexible desktop tool for system-response modeling of active feedback. The nature of the tool should allow it to be easily used by researchers for a variety of systems, enabling its quick application to any current or future tokamak.