GWA-WG 1 G Losurdo INFN Florence H

GWA-WG 1 G. Losurdo – INFN Florence H. Grote – AEI Hannover on behalf of WG 1

WG 1 mission q 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 q Activity started in 2004 (first meeting in July 2004) q Many progress in 2. 5 years, but the commissioning of Virgo and GEO is not over. WG 1 remains a precious environment for exchanging expertise ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 2

The group S. Hild H. Grote (co-chairman) H. Lueck J. Smith A. Freise M. Barsuglia H. Heitmann P. La Penna G. Losurdo (co-chairman) L. Taffarello M. Visco GEO 600 Virgo Bars Not a closed group: we invite many people involved in commissioning to attend and talk ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 3

Meetings held so far 1 st meeting, 2 nd meeting, 3 rd meeting, 4 th meeting, 5 th meeting, 6 th meeting, 7 th meeting, 8 th meeting, 9 th meeting, Cascina, Jul 7 -8 2004 Hannover, Sep 23 -24 2004 Cascina, Jan 24 -26 2005 Hannover, April 7 -8 2005 Telecon, Jul 14 2005 Perugia, Sep 19 -20 2005 Hannover, Dec 12 2005 Frascati, Mar 20 -21 2006 Potsdam, Jul 21 -22 2006 10 th meeting, Cascina, Nov 13 -14 2006 ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 4

GEO/Virgo commissioning progress Virgo: 4 months to upgrade the input bench GEO: last 6 months In science run (S 5, 24/7) ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 5

WG 1: 4 -years execution plan MILESTONES DELIVERABLES YEAR 1 04 -05 Working group set-up GEO/Virgo noise sources comparison YEAR 2 05 -06 GEO/Virgo joint noise characterization Development of common characterization algorithms YEAR 3 06 -07 GEO/Virgo joint noise characterization Implementation of common characterization algorithms Annual report GEO/Virgo joint noise characterization Annual report Recommandations report for short term improvements YEAR 4 07 -08 ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 Annual report Recommandations report for short term improvements G. Losurdo – INFN Firenze 6

WG 1: last year meetings content q Dec. 2005 – Hannover – – – q Mar. 2006 – Frascati – – q Installation of the new injection bench and mode matching at Virgo Alignment noise. Sources of high frequency noise Power line harmonics. Magnetic couplings to test mass motion Suspension control issues Special invited talk: “Measurements of small forces at very low frequencies” Tools for noise analysis The “owl” noise at GEO – brainstorming Jul. 2006 - Potsdam – – Alignment noise Automation issues Glitch measurement and removal Thermal lensing and simulation tools ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 7

3 rd year milestones GEO/Virgo joint noise characterization Implementation of common algorithms ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 8

GEO data read with Virgo data. Display A. Freise ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 9

Virgo data to be read with GEO data viewer J. Smith, M. Hewitson Features: Time-series Spectrum (ASD, AS, PSD, PS) Coherence Transfer function Spectrogram Heterodyne Bicoherence IIR filtering (highpass, lowpass, bandpass, pole-zero) Resampling à Can read GEO, Virgo, LIGO frames à Install as test software at Virgo in Nov. ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 10

Laser power noise in Virgo/GEO J. Smith, G. Vajente Noise coupling estimated primarily with formulas/models in Virgo, measurement in GEO. The projects can learn from each other. ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 11

GEO glitch monitor q Finds and parameterizes excess power events. – q This is the most useful glitch tool used in GEO. – q Has led to numerous reductions in glitches. Tested/debugged for about 6 yrs. – – q DB mining allows coincident analysis, etc. Parameter estimation tested and tuned with injections and real events. Saves re-inventing the wheel !! Might be useful for Virgo J. Smith ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 12

Monitor of non-stationary noise q Online computation of band-limited RMS and line identification q Time series Offline analysis – – q Time series Spectral analysis Coherence with interferometer channels Identification of non-stationarity sources Might be useful for GEO Spectra Coherences G. Vajente ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 13

Noise budget Noise projections and automated noise budget now used in both experiments. GEO uses almost entirely measured transfer functions Virgo uses also modelled TFs ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 14

Special activities A few parallel projects have been carried on within the WG 1 framework, dealing with commissioning-related topics: q The windmills project q The beam centering project q The alignment optimization project q The joint noise characterization project (talk by J. Smith) WINDMILLS 1 st telecon, May 12, 2005 Team meeting, Cascina, 7 -9 June 2005 Seismic survey, GEO 600 site, July 25 -29 2005 2 nd telecon: August 25, 2005 BEAM CENTERING ALIGNMENT 1 st meeting, Birmingham, August 2006 JOINT NOISE CHARACTERIZATION 1 st report, Cascina, September 11 -22 2006 2 nd report, Cascina, October 16 -20, 2006 1 st meeting, Napoli-Cascina, June 10 -14, 2005 ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 15

The Windmills project q Costruction of two windmills stations near Virgo proposed. Concern for seismic disturbance q The wind park next to GEO 600: chance to study the windmills seismic wave field in a soft soil similar to the Virgo one. q Seismic survey on GEO 600 site using two stations run in coincidence q Built a model of noise spectral composition and soil attenuation used to predict effects of the wind parks at Virgo, and define a safety distance of 5 km from Virgo buildings q Positive reaction of both windmill companies, which modified projects layout to comply with our request. q Joint VIRGO-GEO 600 document: VIR-NOT-PIS-1390 -317 (I. Fiori L. Giordano S. Hild G. Losurdo E. Marchetti G. Mayer F. Paoletti) ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 16

The beam centering project q Centering of beam used for wavefront sensing on the quadrants is essential for the robustness of the alignment system q Virgo quadrants are centered with a low bandwidth (<0. 3 Hz) control – – Not enough to reduce rms considerably Noisy system q GEO uses a commercial galvanometer scanner with custom mechanics and electronics. q 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 GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 17

The alignment optimization project q Sensing matrix optimization – q Use the distribution of the matrix’ row vectors in the system's parameter space. Compute the separation of the diode signals in the space of the mirror angular movements. Controllability: – q A. Freise, M. Mantovani Study of the dependence of the controllability of a simple system (a FP cavity using the Ward and the Anderson technique) on the parameters of the optical readout in order to validate and check the performance the chosen test method Alignment noise propagation in Virgo under study VIRGO configuration: Result of the study on the controllability on a complex configuration as the VIRGO alignment system. The minimum separation between the 'best' sub-set of signal vectors is shown as a function of Gouy and demodulation phase (for the NE diodes). The chosen alignment control system can thus control all the required degrees of freedom and it can improved by tuning the parameters of the optical readouts. ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 18

Conclusive remarks q WG 1 still very useful for the commissioning of Virgo and GEO q Meetings focused on noise hunting q Beside ordinary meetings, a set of “parallel” projects spread out of WG 1 q A fellowship for Virgo-GEO joint noise characterization has been granted within WG 1: precious to fulfill the last milestones of the 4 -years project ILIAS GWA Annual Meeting - London, Oct 26 th, 2006 G. Losurdo – INFN Firenze 19