Damping parametric instabilities in future gravitational wave detectors by means of electrostatic actuators

Abstract

It has been suggested that the next generation of interferometric gravitational wave detectors may observe spontaneously excited parametric oscillatory instabilities. We present a method of actively suppressing any such instability through application of electrostatic forces to the interferometers' test masses. Using numerical methods we quantify the actuation force required to damp candidate instabilities and find that such forces are readily achievable. Our predictions are subsequently verified experimentally using prototype Advanced LIGO hardware, conclusively demonstrating the effectiveness of our approach.