l | ll[ll I 1-'1,'i |; ii"&'l [LI,~I PROCEEDINGS SUPPLEMENTS ELSEVIER Nuclear Physics B (Proc. Suppl.) 54B (1997) 167-175 The VIRGO Interferometer For Gravitational Wave Detection B. Caron, A. Dominjon, C. Drezen, R. Flaminio, X. Grave, F. Marion, L. Massonnet, C. Mehmel, R. Morand, B. Mours, V. Sannibale, M. Yvert Laboratoire de Physique des Particules (LAPP), IN~P3.CNRS, 74941 Annecy-Le-Vieux Cedex, France D. Babusci, S. Bellucci, S. Candusso, G. Giordano, G. Matone Laboratori Nazionali deU'INFN (LNF-INFN), 00044 Frascati, Italy J.-M. Mackowski, L. Pinard Universitd Claude Bernard, IPNL, IN2P3-CNRS, 69622 Villeurbanne Cedex, France F. Barone, E. Calloni, L. Di Fiore, M. Flagiello, F. Garuti, A. Grazlo, M. Longo, M. Lops, S. Marano, L. Milano, S. Solimeno Dipartiraento di Scienze Fisiche dell'Universit~ e INFN Sezione di Napoli, 80125 Napoli, Italy V. Brisson, F. Cavalier, M. Davier, P. Hello, P. Heusse, P. Mann Laboratoire de i'Accdldrateur Lindaire, Universit~ Paris-Sud, IN2P3-CNRS, 91405 Orsay CEDEX, France Y. Acker*, M. Barsuglia, B. Bhawal, F. Bondu, A. Brillet, H. Heitmann, J.-M. Innocent, L. Latrach, C. N. Man, M. Pham-Tu, E. Tournier, M. Taubmann, J.-Y. Vinet Laser Optique Orsay, Universitd Paris-Sud, INPP3-CNRS, 91405 Orsay CEDEX, France C. Boccara, Ph. Gleyzes, V. Loriette, J.-P. Roger Laboratoire de Spectroscopie en Lumi~re Polarisde, Ecole Supdrieure de Physique et Chirnie lndustrielle, 75005 Paris, France G. Cagnoli, L. Gammaitoni, J. Kovalik, F. Marchesoni, M. Punturo Dipartimento di Fisica dell'Universit~ e INFN Sezione di Perugia, 06100 Perugia, Italy M. Beccaria, M. Bernardini, E. Bougleux t, S. Braccini, C. Bradaschia, G. Celia, A. Ciampa, E. Cuoco, G. Curci, R. Del Fabbro, R. De Salvo, A. Di Virgilio, D. Enard t, I. Ferrante, F. Fidecaro§, A. Giassi, A. Giazotto, L. Hollowayt, P. La Penna, G. Losurdo, S. Maneini, M. Mazzoni t, F. Palla, H.-B. Pan, D. Passuello, P. Pelfer t, R. Poggiani, R. Stanga t, A. Vicere', Z. Zhang Dipartimento di Fisica deil'Universitd, INFN Sezione di Pisa e Scuola Normale Superiore, 56010 S. Piero a Grado, Italy V. Ferrari, E. Majorana, P. Puppo, P. Rapagnani, F. Ricci Dipartirnento di Fisica dell'Universitd "La Sapienza" e INFN Sezione di Roma 1, 00185 Roma, Italy The Virgo gravitational wave detector is an interferometer with 3 km long arms in construction near Pisa in Italy. The accessible sources at the design sensitivity and main noises are reviewed. Virgo has devoted a significant effort to extend sensitivity to low frequency re~ching the strain level/~ = 10-21 Hz -1/2 at 10 Hz while at 200 Hz h = 3- 10-z3 Hz -1/2. Design choices and status of construction are presented. *INSU-CNRS, France. ?INFN Firenze, Italy. IOn leave from ESO, Garching, Germany. §To whom correspondence should be addressed. IUniversity of Illinois, Urbana-Champaigne, USA. 0920-5632/97/$17.00 © 1997 Elsevier ScienceB.V. All rights reserved. PII: S0920-5632(97)00109-6 1. INTRODUCTION Observation of light deviation by the Sun in 1919 [1] was a spectacular confirmation of the pre- dictions of General Relativity Theory. This the- ory had also been able to interpret in a natural way the precession of Mercury orbit perihelion. Still the measurements were at the 10% level (ex-