Long duration plasma control in the fully metallic tokamak WEST

WEST is a metallic tokamak designed for long pulse operation with actively cooled components. The main missions of WEST include high fluence plasma divertor exposure and long pulse H-mode demonstration in a full tungsten environment. Achieving long duration and high performance plasma discharges, while ensuring machine protection, requires features such as specific controllers to keep the plasma in a steady state for several minutes. This paper presents the plasma current and loop voltage controllers implemented into the WEST Plasma Control System to achieve plasma of 1000 s. A simple circuit equation is used to model the tokamak and then the controllers are designed accordingly; their parameters are identified using the WEST database. The controller is then tuned and tested in simulation before being deployed on WEST. Experimental results are presented to illustrate the efficiency of the controller.