New suspension system for the gravitational wave bar detector AURIGA

We report on the design of the new suspension system for the gravitational wave bar detector AURIGA. The system was designed with the aid of finite element modeling simulations with the goal of achieving at least -240 dB of vibration reduction at 900 Hz in a cryogenic environment, while preserving a high mechanical quality factor. We report room temperature measurements of the suspension core stage, mode frequencies, and attenuation and we discuss them on the basis of the simulation predictions. The suspension system is currently installed in the detector, which is properly working at the operating temperature of 4.2 K. The observed improvements related to the suspension design are reported and discussed. (c) 2005 American Institute of Physics.