Estimation and Exploratory Regulation of Confinement-Time Based Plasma Performance in the DIII-D Tokamak Experiment.

The global confinement time is a critical parameter for characterization of plasmas in magnetic confinement fusion experiments. A practical nonlinear ensemble Kalman filter is developed for estimation of the global energy confinement time. The filter implementation runs in real time and provides quality estimates enabling novel modes of tokamak plasma feedback. Open and closed loop experimental results are reported for the regulation of a confinement time based plasma performance metric, using the total plasma current as actuator.