Femto-Newton level testing of free-fall on-ground
The realization of free-fall is central for the experimental detection of gravitational waves and for all experiments aimed at probing the limits of general relativity and the possibility of alternative theories of gravitation. Tidal effects from gravitational waves and deviations from general relativity are expected to be extremely tiny and require very low levels of non gravitational acceleration acting on the test masses. This implies the reduction and control of the disturbances produced by a wide range of physical phenomena, requiring ground-breaking achievements within their relevant fields of science.
Among other general relativity experiments, the Laser Interferometer Space Antenna - LISA - is a joint effort of ESA and NASA to realize the first high sensitivity gravitational wave observatory in space. It aims to observe gravitational waves emitted from galactic and cosmological sources in the frequency range from 0.1 mHz to 0.1 Hz. Testing the possibility of achieving the quality of free-fall required by LISA has been the motivation of the development and realization of a torsion pendulum facility for small force measurements. The realization of this test bench has the aim to conduct an experimental campaign focused on characterization of the disturbances exerted in the mHz and sub mHz frequency region on the test masses.
In this talk I will describe the recent developments of the torsion pendulum facility and recent results of the characterization of single force noise sources.