The Virgo interferometer

Caron, B.; Dominjon, A.; Drezen, C.; Flaminio, R.; Grave, X.; Marion, F.; Massonnet, L.; Mehmel, C.; Morand, R.; Mours, B.; Sannibale, V.; Yvert, M.; Babusci, D.; Bellucci, S.; Candusso, S.; Giordano, G.; Matone, G.; Mackowski, J. M.; Pinard, L.; Barone, F.; Calloni, E.; Difiore, L.; Flagiello, M.; Garufi, F.; Grado, A.; Longo, M.; Lops, M.; Marano, S.; Milano, L.; Solimeno, S.; Brisson, V.; Cavalier, F.; Davier, M.; Hello, P.; Heusse, P.; Mann, P.; Acker, Y.; Barsuglia, M.; Bhawal, B.; Bondu, F.; Brillet, A.; Heitmann, H.; Innocent, J. M.; Latrach, L.; Man, C. N.; Phamtu, M.; Tournier, E.; Taubmann, M.; Vinet, J. Y.; Boccara, C.; Gleyzes, P.; Loriette, V.; Roger, J. P.; Cagnoli, G.; Gammaitoni, Luca; Kovalik, J.; Marchesoni, Fabio; Punturo, M.; Beccaria, M.; Bernardini, M.; Bougleux, E.; Braccini, S.; Bradaschia, C.; Cella, G.; Ciampa, A.; Cuoco, E.; Curci, G.; Delfabbro, R.; Desalvo, R.; Divirgilio, A.; Enard, D.; Ferrante, I.; Fidecaro, F.; Giassi, A.; Giazotto, A.; Holloway, L.; Lapenna, P.; Losurdo, G.; Mancini, S.; Mazzoni, M.; Palla, F.; Pan, H. B.; Passuello, D.; Pelfer, P.; Poggiani, R.; Stanga, R.; Vicere, A.; Zhang, Z.; Ferrari, V.; Majorana, E.; Puppo, P.; Rapagnani, P.; Ricci, F.

The Virgo gravitational wave detector is an interferometer with 3 km long arms in construction near Pisa to be commissioned in the year 2000. Virgo has been designed to achieve a strain sensitivity (SNR = 1) of a few times 10(-23) Hz-(1/2) at 200 Hz, A large effort has gone into the conception of the mirror suspension system, which is expected to reduce noise to the level of 10(-21) Hz(-1/2) at 10 HZ. The expected signals and main sources of noise are briefly discussed; the choices made are illustrated together with the present status of the experiment.