Taming drift wave turbulence

Drift waves in magnetized plasmas often occur in a turbulent form and are o ften considered as being responsible for anomalous cross-field particle tra nsport. It is thus very appealing to achieve active control of the drift wa ve dynamics. A control scheme acting both in space and in time is developed to synchronize drift wave turbulence. It consists of an arrangement of eig ht electrodes (octupole exciter) in flush-mounted geometry in the edge regi on of the magnetized plasma column. The electrodes of the octupole exciter are driven by sinusoidal signals. Between each two neighbouring electrodes, the phase shift of the exciter signal is kept fixed. It is demonstrated ex perimentally that the exciter signals have strong influence on the differen t drift wave states, i.e. the turbulent states can be synchronized to a sin gle preselected drift wave mode. The efficiency of the spatiotemporal synch ronization is sensitively dependent on both driver frequency and phase shif t.