The antiseismic suspension for the VIRGO project

Gravitational waves propagating from rapidly accelerating star masses can be detected by means of interferometric techniques. Several interferometric antennas are presently under construction around the world with the aim of gravitational waves detection in the frequency range starting from a few tens of Hz to a few kHz. In the low frequency region (below a few tens of Hz) their detection is limited by seismic noise which can mask the weak signal induced by a gravitational wave impinging on a suspended mirror. In order to overcome this limitation, the VIRGO collaboration has developed and built a sophisticated suspension system to isolate the optical components from the seismic noise. This mechanical system, called SuperAttenuator, is able to inhibit the transmission of any mechanical disturbances starting from about 4 Hz thus extending the detection band in the low frequency region.