Variable gain-phase method for feedback stabilization of multimode plasma instabilities

A method of feedback stabilization of multimode plasma instabilities using only one pair of sensor and controller has been developed. The gain and phase requirements of the feedback structure are obtained from the usual single mode stabilization technique. Then a physically realizable feedback system is derived with this gain-phase characteristics at modal frequencies. The method is applied to multimode weak reactive and dissipative electrostatic plasma instabilities.