1. ILIAS-GWA WP1 BUILDING UP THE EUROPEAN GW COMMUNITY
H.Grote - G. Losurdo
WP1 co-chairs

2. FROM ILIAS TO ET
The main members of the European GW Community joined their forces in ET
Hard to be conceived a few years ago. Long path walked together in the ILIAS framework
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 2

3. ILIAS-GWA Objectives Increase the level of EU coordination
Maximise return on large investments already made
Enhance the performance of existing detectors
Prepare the future of this discipline in Europe
Improve the exchange of infos on subjects of common interest
Foster the development of common methodologies for joint observations
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 3

4. WP1
Objectives
To speed up the commissioning and the characterization of Virgo and GEO by means of a deeper collaboration between the two teams*
To develop common methods of characterization of interferometric GW detectors to be applied to Virgo and GEO
To provide inputs for establishing priorities for short term improvements of the existing interferometric detectors on the base of the Virgo and GEO characterization
* Two appointed WP1 members come from the resonant detectors community
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 4

5. WP1 – FURTHER ACHIEVEMENTS
Today: A real collaboration among a group of young physicists has been established. Reciprocal confidence has been built.
Tomorrow: the grown-up WG1 fellows will hopefully continue to collaborate and might lead the joint effort for a new EUROPEAN detector.
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 5

6. DETECTORS AT ILIAS STARTUP (2004)
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 6

7. EXECUTION PLAN Extended to 5th year
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 7

8. WP1 ACTIVITY PARALLEL PROJECTS WP1 meetings The windmills project
environmental
noise studies
WP1 meetings
1st meeting, Cascina, Jul
2nd meeting, Hannover, Sep
3rd meeting, Cascina, Jan
4th meeting, Hannover, April
5th meeting, Telecon, Jul
6th meeting, Perugia, Sep
7th meeting, Hannover, Dec
8th meeting, Frascati, Mar
9th meeting, Potsdam, Jul
10th meeting, Cascina, Nov
11th meeting, Hannover, Jan 23-24, 2007
12th meeting, CERN, Mar 29-30, 2007
13th meeting, Cascina, Jun 19-20, 2007
14th meeting, Hannover, Oct 22-25, 2007
15th meeting, Cascina, Mar 5-6, 2008
16th meeting, Birmingham, Jul , 2008
The windmills project
1st telecon, May 12, 2005 Team meeting, Cascina, 7-9 June 2005 Seismic survey, GEO600 site, July nd telecon, August 25, 2005
The beam centering project
1st report, Napoli-Cascina, June 10-14, 2005
interferometer
controls
The alignment simulation project
1st meeting, Birmingham, August 2006
The joint noise hunting project
1st report, Cascina, September nd report, Cascina, October rd report, Cascina, November th report, Cascina, January
Summary report
sensitivity
studies
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 8

9. SOME STATISTICS and curiosities
16 ordinary meetings + parallel projects
Meetings usually held at Cascina/Hannover but also Perugia, Frascati, Potsdam, CERN, Birmingham
10 appointed members (2 students)…
…but 35 different speakers (of which 13 students)
Stefan Hild
FIDELITY AWARD: 15 talks in 16 meetings
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 9

10. NOISE STUDIES
Deep and fruitful discussions on methods for noise hunting (projections, coherence, noise propagation models, time-frequency methods, …)
Noise projection proposed by GEO now widely used
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 10

11. NOISE STUDIES
Stray light (or scattered light) is an important noise source for all of the interferometric detectors, and is hard to foresee and modelize
Extremely small amounts of light power can cause significant problems
Diagnostics:
Search of spurious beams
Acoustic noise injections
Tapping/hammering tests
Noise reduction techniques:
New optical layouts for auxiliary beams
Larger/higher quality optics
AR-coated windows on photodiodes
Beam dumps
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 11

12. THE JOINT NOISE HUNTING PROJECT
A 9 months post-doc fellowship granted within ILIAS-N5 WP1.
J.Smith (GEO) spent 25% of time at Virgo site
Common noise investigations
Virgo alignment noise projections
Virgo laser power noise investigations
GEO noise transfer functions simulation
General noise hunting at both sites
Knowledge exchange
Common algos/Software exchange
GEO algo for glitch parameterization implemented at Virgo
GEO data viewer used at Virgo to listen to “dark fringe music” and for off-line analysis of data
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 12

13. TOOLS EXCHANGE
GEO glitch monitor available at Virgo. Precious “commissioning oriented” tool for understanding detector noise
Every point is a glitch: an excess of power for some short period of time (tens of ms) and a narrow frequency band (tens of Hz)
data quality
detector noise characterization
vetoing
J. Smith - G. Vajente
HACR at Virgo
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 13

14. THE WINDMILLS PROJECT
Costruction of two windmills stations near Virgo proposed. Concern for seismic disturbance
The wind park next to GEO600: chance to study the windmills seismic wave field in a soft soil similar to the Virgo one.
Seismic survey on GEO600 site using two stations run in coincidence
A model of noise spectral composition and soil attenuation was done and used to predict effects of the wind parks at Virgo. A safety distance of 5km from Virgo buildings was defined.
Positive reaction of both windmill companies, which modified projects layout to comply with our request.
Joint VIRGO-GEO600 document: VIR-NOT-PIS (I.Fiori L.Giordano S.Hild G.Losurdo E.Marchetti G.Mayer F.Paoletti)
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 14

15. SHORT TERM IMPROVEMENTS
During commissioning both detectors underwent to upgrades
Deep discussion in the WG, to exchange experience and “warn” about risks
Short term improvements
Virgo new injection bench
Virgo new PR mirror
Virgo new IMC mirror
Suspension control improvements
IMC auto-alignment
Fast centering of quadrants for auto-alignment
Acoustic noise reduction
Scattered light reduction
Control noise reduction
Radio frequency distribution system
Thermal compensation
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 15

16. The beam centering project
Centering of beam used for wavefront sensing on the quadrants is essential for the robustness of the alignment system
Virgo quadrants are centered with a low bandwidth (<0.3 Hz) control
Not enough to reduce rms considerably
Noisy system
GEO uses a commercial galvanometer scanner with custom mechanics and electronics.
Succesfully tested on Virgo: very good suppression of beam fluctuations
Galvo off
Galvo on
R.De Rosa, L. Di Fiore, H.Grote,
H.Heitmann, J.Marque,
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 16

17. TOWARDS ILIAS END
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 17

18. Once fragile, interferometers have become robust and reliable!
ROBUST INSTRUMENTS
18 May - 1 October 2007
Instrumental duty cycle: 84.2%
Science time duty cycle: 81 %
Longest lock: 94 hours
Once fragile, interferometers have become robust and reliable!
1 May - 15 October 2007
Instrumental duty cycle: 94.3%
Science time duty cycle: 91 %
Longest lock: 102 hours
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 18

19. ILIAS-GWA has eased to process of creating a European GW community
CONCLUSIVE REMARKS
After a long commissioning the interferometric detectors of GW are entering the science era
The European GW community has plans for the upgrades from generation 1.5 (Virgo+), 2 (Advanced Virgo, GEO HF), 3 (E.T.)
ILIAS-GWA has eased to process of creating a European GW community
ILIAS-ET Joint Meeting – Cascina, Nov. 25th, G.Losurdo – INFN Firenze 19