CAN PIEZOELECTRIC ACCELEROMETERS BE USED TO ACTIVELY DAMP THE MECHANICAL SUSPENSIONS IN LASER INTERFEROMETRIC GRAVITATIONAL-WAVE DETECTORS

An investigation of the use of mass-loaded piezoelectric accelerometer s for active damping of high Q, mechanical, vibration isolation suspen sions is reported. The transfer function and noise of the acceleromete r are modeled, and the predicted noise compared with measurements. A s ervo which damps the normal modes of a two-stage suspension by sensing the acceleration of, and feeding back to, the intermediate mass is th en modeled. The rms and ''high frequency'' closed loop motions of the isolated mass are calculated. (C) 1996 American Institute of Physics.