A Kalman Filter for n > 1 Resistive-Wall-Mode Identification and Feedback Control Modeling

The simulation of fusion plasmas is important to the development of plasma discharge feedback and control techniques. In particular, recent progress on the identification of the n=1 resistive-wall-mode and its relationship to feedback control has shown promise. However, as the n=1 mode is feedback controlled, higher toroidal resistive wall modes (RWMs) ¿ i.e, those modes with n>1 ¿ may become unstable and provide a performance-limiting instability. Nevertheless, little work has been performed for the identification and feedback control of these n>1 RWM modes. Therefore, this project will develop a Kalman filter that discriminates noise in RWM mode identification for n>1 modes, as well as for n=1 modes. Phase I will develop a state-space model that serves as the basis for constructing a Kalman filter that is compatible with both n=1 and n>1 RWM modes. The feasibility of real-time RWM identification of n=2 and n=3 modes will be validated by using DIII-D tokamak data. Commercial Applications and Other Benefits as described by the awardee: A Kalman filter for n>1 resistive-wall-mode identification and feedback control modeling should enable the achievement of advanced fusion tokamak plasmas. In addition, the Kalman-filter modeling tool would provide a flexible desktop tool for the modeling of active feedback