Central mass feedback control using the discrete Alfvén wave spectrum

The dispersion relation of the shear Alfvén wave depends on several internal plasma parameters, including the central effective mass. By frequency tracking a discrete Alfvén wave during the plasma current flat-top, a real time estimate of the central effective mass is obtained. Using this measured mass, the effective mass and the electron density can be separately feedback controlled, via independent hydrogen and deuterium filling valves.