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 predicted by currently accepted theoretical models.
The Virgo groups are also involved in some
R&D activities, considered and managed as sub-projects aiming at insuring
2.
Activities during 2002
Virgo experiment is beginning its activity in 2002, but
it was preceded by a long Special Project (1994-2001), which was entirely
devoted to the construction of the antenna with all related infrastructures. The
commissioning of the Central Interferometer (a suspended 6 m Michelson
interferometer without Fabry-Pérot cavities) has been ended in the Summer 2002,
and many engineering runs have been performed: analysis of the produced data is
now completed and furnished fundamental information about locking strategy to be
followed for the 3 km detector too. The Assembly and Integration of the overall
antenna is almost completed, even though for ending tower some activity on
(final) test masses will be finished at the beginning of 2003. For what concerns
R&D activities, LF Facility concluded a first run: acquired data are now
being analyzed. The CRYSTAL sub-project received good financial support only
during last summer: the hardware structure is just started and will be completed
when all components will be delivered from companies. The UVVV activity has been
unfortunately stopped due to problems on the laser: we are now ending all tests
and well be able to recover the delay reaching full operating state in the
first half of 2003.
It is to be underlined that despite the lack of funds
for calculus, some fundamental tests for distributed calculus have been
performed on the clusters of FI/Ub-PG-NA-RM1 Sections.
The Collaboration is now involved in detailed Plan for
the Commissioning of Virgo 3km.
The following achievements have been obtained:
Milestones 2003
Tests on catalytic gluing of fused silica-silicon for suspension wires-mirror system | 30-04-2003 |
Implementation of both classic and adaptive control techniques on isolated mirrors | 30-06-2003 |
Implementation of non-linear alignment and local control on Virgo 3 km | 31-08-2003 |
Implementation and verification of final active filtering loops on every SA in Virgo | 15-09-2003 |
Substitution of the LFF payloads with the final one | 15-09-2003 |
First full tests on substrates for cold mirrors | 31-10-2003 |
Final version and related upgrade of the system for measuring opto/mechanical transfer function on the last stage of SAs | 30-11-2003 |
Run and related analysis on LFF data | 15-12-2003 |
Stability and performance tests on the prototype for adaptive optics control | 31-12-2003 |
Preliminary tests on electrostatic pushers and related electronics on a suspended mirror | 31-12-2003 |
End of debugging and of commissioning crucial phases for Virgo 3 km | 31-12-2003 |
Ending of Assembly and Integration Virgo 3 km | 31-01-2003 |
3. INFN contribution to the experiment in terms of manpower
Manpower: 73 researchers (55.1 FTE), 18 technicians (7.6 FTE)
Budget for the Year 2003: 5.7 % of the CSN2 budget for 2003
4. Publications in refereed journals (year 2002): 7
5. Conference talks (year 2002): 6
6. Number of undergraduate and doctoral theses on the experiment: 12
7. Leadership roles in the experiment
8. Innovative instruments
9. Competing experiments
10.
International
Committee which has reviewed the experiment
Scientific and Technical Advisory Committee (EGO STAC)