Experimental determination of a nonlinear dynamic model of plasma turbulence using feedback control

A new and convenient method to experimentally determine nonlinear dynamical models of plasma turbulence is described. It is based on a novel use:of fe edback control which generates information about the model without introduc ing additional unknowns. The method is applied to an E X B turbulence in th e Columbia Linear Machine to determine the linear eigenfrequencies and nonl inear coupling coefficients of a three wave coupling model-directly: from-e xperimental data.