Status report of the low frequency facility experiment, Virgo R&D

Abstract The low frequency facility, a Virgo RD the goal is to measure the thermal noise of the apparatus above 10 Hz, with a displacement sensitivity as high as 10 −18  m / Hz . Since September 2001 the apparatus, located inside the INFN-Pisa experimental area, has been completely built and put into operation. Vacuum facilities and the control loops have been set up. Transfer functions, necessary to control the cavity, absolute test mass displacement and the first demonstration of the cavity locking are reported.