Gonzalez An improved, double-pendulum suspension system for the test of masses in gravitational wave detectors will be designed and a prototype will be built. It will provide a feasible way of suspending and controlling the test masses in the LIGO detector environment. Different sensors of the pendulum modes and actuators on the pendulum masses will be designed and tested on the prototype.
Several interferometric gravitational wave detectors are now in construction around the world. They use various different ways of suspending the test masses so that they can be isolated from seismic noise and treated as free masses for the gravitational field in the widest possible frequency range. A choice of a suspension design represents a delicate balance between seismic isolation, thermal noise, reliability and control design. The initial design for the LIGO detectors is the simplest pendulum design. The effort at Penn State, integrated with the work of other groups in the LIGO Science Collaboration, will provide a design and a prototype of a better suspension system that will increase the sensitivity of the LIGO detectors at low frequencies by reducing the seismic and thermal noise contributions. ***
