Feedback-modulated ion beam stabilization of a plasma instability

A novel remote suppressor consisting of an injected ion beam has been used for the stabilization of a plasma instability. Plasma instabilities can, for the first time, be remotely suppressed by modulating the ion beam with an appropriately phased and amplified feedback signal derived from a sensor probe. A collisionless curvature-driven trapped-particle instability has been successfully suppressed down to noise levels using this scheme. The ion beam causes only a small perturbation to the plasma, on the order of 1%, so that the plasma equilibrium parameters are not significantly affected.