Virgo
Antenna in Càscina
The
structure of the Virgo Antenna is now complete: an overall view is shown in the
figure; the goal in sensitivity of the full Interferometer (a suspended
Michelson with perpendicular arms constituted by two 3 km Fabry-Pérot resonant
cavities) is represented below. A very sophisticated structure (the
Superattenuator, a tower 10 m high) has been designed in order to suspend test
masses (mirrors and beam-splitter). A
power recycling cavity and a 144 m long Mode Cleaner guarantee a high power
injection and a pure TEM00 for the beam generated by a 20 W Nd:Yag
laser (l
= 1064 nm). The Commissioning of the Central Interferometer (a suspended 6 m
Michelson, without 3 km arms) is now ended: sensitivity reached during
engineering runs is shown in the last figure.