# VIRGO

# Collaboration:

- Italy: Firenze, Lab. Naz. Frascati, Napoli, Perugia, Pisa, Roma1, Urbino(Firenze)
- France: ENS (Lyon), ESPCI (Paris), LAL (Orsay), LAPP (Annecy), OCA (Nice)).

Laboratory: EGO, Cascina

National Responsible: F. Vetrano (Urbino/Fi)

Home page of the experiment: http://www.virgo.infn.it/

1. Goal of the experiment

The scientific goal of the experiment, after the end of the construction and the commissioning of the interferometric gravitational antenna Virgo (a suspended Michelson interferometer, with 3 km Fabry-Pérot cavities as orthogonal arms), is to reach sensitivity enough, to take data, to develop analysis strategy, in order to be able to detect gravitational waves from astrophysical and/or cosmological sources, provided their amplitudes are those by currently accepted theoretical models.

2.

Activities during 2001

Virgo experiment is beginning its activity in 2002, but it was preceeded by a long Special Project (1994-2001), which was entirely devoted to the construction of the antenna with all related infrastructures. The construction and the commissioning of the Central Interferometer (a suspended 6 m Michelson interferometer without Fabry-Pérot cavities) are now approaching the end, and the commissioning of CITF has been a good fundamental learning for the way along with we will move towards Virgo-3km, showing fundamental characteristics of detector noise against which we are (and we will be) fighting.

Milestones 2002

Completion of the towers at the end of the interferometer | 31-05-2002
Debugging of the interferometer | 30-09-2002
Full planning of the interferometer Commissioning | 31-11-2002
Conclusion of the tests for distributed calculus on the FI/Urbino- PG-NA-Roma1 clusters for Virgo data analysis | 31-12-2002

3. INFN contribution to the experiment in terms of manpower

Manpower: 83 researchers (62.8 FTE), 19 technicians (8.5 FTE)

Budget for the Year 2002: 1108,5 kEuro

4. Publications in refereed journals (Year 2001): 8

5. Conference talks (Year 2001): 9

6. Number of undergraduate and doctoral theses on the experiment: 12

7. Leadership roles in the experiment

- National Spokesperson of the Italian Virgo Collaboration is Flavio Vetrano from Urbino University & Florence INFN Section.
- International Spokesperson of the French-Italian Virgo Collaboration is Adalberto Giazotto from Pisa INFN Section.

8. Innovative instruments

- inertial sensors (accelerometers) both for translation and rotation, of very high sensitivity under U.H.Vacuum conditions, operating from very low-frequency up to 1kHz
- heat treatment (400ºC, open air) for stainless steel up to an intrinsic outgassing rate lower than 10-14 mbar l/s/cm2
- production of suspension wires with high breaking strength (5 Gpa) and very low internal loss angle (lower than 10-7)

9. Competing experiments

LIGO (USA)