1. Advanced Virgo advanced Giovanni Losurdo – INFN Firenze Advanced Virgo Coordinator for the Virgo Collaboration Requires the font “calibri”. DOWNLOAD

2. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 2  SCIENCE and INTERNATIONAL CONTEXT  AdV BASELINE DESIGN  ORGANIZATION AND COST PLAN OF THE TALK

3. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 3  SCIENCE and INTERNATIONAL CONTEXT  AdV BASELINE DESIGN  ORGANIZATION AND COST PLAN OF THE TALK

4. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 4 GW TELESCOPES LIGO – Livingston, LA VIRGO, Pisa, Italy GEO600, Hannover, Germany LIGO – Hanford, WA A network of 4 (5) GW detectors For the first time, one session dedicated to GW at the AAS conference (Jan 08)AAS conference Advanced LIGO/Virgo presented by a Virgo member INFN labs in the the Virgo Collaboration: Firenze/Urbino Genova Napoli Padova/Trento Perugia Pisa Roma 1 Roma 2

5. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 5 Triangulation allows to pinpoint the source The network allows to deconvolve detector response and signal waveform  measure signal parameters SCIENCE WITH A NETWORK False alarm rejection requires coincidence Longer observation time, better sky coverage

6. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 6 SCIENCE WITH A NETWORK SIMULATION: burst at the galactic center  Detector angular response not isotropic  The network improves the sky coverage  Triple coincidence allows to measure the source direction with an accuracy of ≈1° (SNR=10) LIGO-Virgo contact group LIGO Hanford Virgo

7. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 7 SCIENCE WITH A NETWORK Advanced Virgo will contribute to the search for a cosmological background: above 100 Hz the SNR for a Virgo/LIGO couple is higher than the one got with the 2 LIGOs Distribution of SNR 4 as a function of the frequency for several pairs of advanced detectors.

8. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 8 THE ASTROPHYSICS: COALESCING BINARIES  NS-NS are standard sirens. 10 events of simultaneous detection with GRBs would allow to measure H 0 to 2-3% [Dalal et al., Phys.Rev.D, 2006]  BH-BH binaries can be sources with high SNR and allow precise waveform measurements, testing GR predictions in strong field regime  A significant rate of detection of coalescing binaries will constrain the binary population synthesis models. A non-detection will have a big impact on the theories of binary evolution  In NS-BH coalescence, the tidal disruption of the NS determines the waveform cutoff and provides information on the NS equation of state [Vallisneri, Phys.Rev.Lett., 2000]

9. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 9 LOW FREQUENCY SENSITIVITY  NSNS, NSBH, BHBH: extreme spacetime curvature probed by GW emission, last stable orbits (LSO) most important  High mass systems have a lower f LSO, so cumulate SNR at low frequency  Promising detectable signals − higher harmonics of high mass BHBH systems with f LSO < 1 Hz − Pulsar emission Advanced Virgo

10. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 10 THE ASTROPHYSICS: PULSARS  Due to EM or GW spin-down, the rotation frequency of NS (10 9 in the galaxy) decreases and tends to exit the sensitivity band of earth interferometers. This is what we observe, e.g., for known pulsars (about 2000 objects up to now).  Having a good sensitivity at low frequency is important because many NS could emit in the 5-50 Hz band even if the expected amplitude is small (it scales as f 2 ) Minimum detectable amplitude (at 1%fap, 10%fdp) for AdV (1 yr observation time) vs amplitude of the GW signals emitted by known pulsars, assuming all the observed spin-down is due to GW emission.

11. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 11 GW TELESCOPES TODAY  LIGO at design sensitivity: technology demonstrated  Virgo is not far. Getting closer to design at low frequency.

12. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 12 VIRGO RECENT PROGRESS After VSR1 run commissioning activity focused on low frequency range. Sensitivity rapidly improving. Exciting progress expected from the next actions

13. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 13 1st GENERATION DETECTORS 1 ST GENERATION INTERFEROMETERS CAN DETECT A NS-NS COALESCENCE AS FAR AS VIRGO CLUSTER (15 MPc) LOW EXPECTED EVENT RATE: 0.01-0.1 ev/yr (NS-NS) FIRST DETECTION: POSSIBLE BUT UNLIKELY

14. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 14 FROM DISCOVERY TO ASTRONOMY 10 8 ly Enhanced LIGO/Virgo+ 2009 Virgo/LIGO Credit: R.Powell, B.Berger Adv. Virgo/Adv. LIGO 2014 GOAL: sensitivity 10x better  look 10x further  Detection rate 1000x larger 2 nd generation detectors: Advanced Virgo, Advanced LIGO Intermediate step: Virgo+, Enhanced LIGO

15. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 15 ADVANCED DETECTORS SENSITIVITY NS-NS detectable as far as 300 Mpc BH-BH detectable at cosmological distances 10s to 100s of events/year expected!

16. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 16 ACHIEVING THE SENSITIVITY GOAL High frequencies: shot noise Mid frequencies: mirror thermal noise Low frequencies: seismic noise Low frequencies: wire thermal noise Achieving a sensitivity 10x better is ambitious. Act on different noise sources: new ideas and a wide R&D program have been necessary

17. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 17 ADVANCED LIGO  NSF Budget signed by the US President. Advanced LIGO ranked as a top scientific project. Expected start-up few weeks after the final formal approval of the NSF executive board (end of March 08)  Positive NSF “readiness review” (Nov 07)  Installation to start in 2011.  All three detectors up in 2014.

18. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 18 ADVANCED VIRGO (AdV) GOALS:  Sensitivity: about 10x better than Virgo  Timeline: be back online with Adv LIGO

19. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 19  SCIENCE and INTERNATIONAL CONTEXT  AdV BASELINE DESIGN  ORGANIZATION AND COST

20. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 20 SUPERATTENUATOR BASELINE:  MECHANICS: VIRGO DESIGN with MODIFICATIONS − Stiffer IP legs − New payload design (MRM), improve cleanliness  CONTROL: 6 dof IP CONTROL (with TILTMETERS)  MIRROR ACTUATION: COIL-MAGNET PAIRS ACTUATORS ALTERNATIVE OPTION: ELECTROSTATIC ACTUATORS - R&D in progress. Advantages and drawbacks to be evaluated.

21. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 21 SUSPENSIONS BASELINE: MONOLITHIC PAYLOAD FIBER GEOMETRY OPTIONS: − The AdV sensitivity is calculated with cylindrical fibers. − More efficient geometries will probably be used (dumbbell fibers or ribbons). Virgo+ activity: dummy mirror suspended with silica fibers

22. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 22 OPTICAL CONFIGURATION BASELINE: DUAL RECYCLED INTERFEROMETER (RSE) – Exact tuning to be defined HIGH FINESSE FP CAVITIES – Reference solution F=885. Optimal value to be defined The base for the SR tower is there

23. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 23 LASER BASELINE: 200 W SOLID STATE LASER AMPLIFIER (LZH) – steady progress! Nice Group is already collaborating with LZH for the Virgo+ amplifier. ALTERNATIVE OPTION: FIBER LASER AMPLIFIER: promising research line, R&D going on

24. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 24 INPUT OPTICS BASELINE: 144 m SUSPENDED RESONANT IMC: Virgo-like solution. − Problem of small angle diffused light to be addressed. ALTERNATIVE OPTION: FIBER LASER IMC − major simplification − locking strategy to be defined

25. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 25 BEAM - DETECTION see talk by A.Freise OPTICAL LAYOUT BASELINE:  TEM 00  WAIST IN THE CAVITY CENTER  LARGER SPOT SIZE ON CORE OPTICS: − requires changing the vacuum links in the central area. DETECTION BASELINE:  PHOTODIODES IN VACUUM  DC DETECTION

26. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 26  PIPE Ø = 600 mm  VALVE Ø = 500 mm

27. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 27 MIRRORS MIRRORS ALTERNATIVE OPTION: 35 cm Ø, 30 cm thick, 63 Kg FP mirrors Useful if fiber geometry is optimized BASELINE:  35 cm Ø, 20 cm thick, 42 Kg FP mirrors  Larger BS (55 cm Ø – TBC)  STATE OF THE ART COATINGS

28. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 28 COATINGS  Sensitivity affected by coating mechanical losses  Coating optical absorption determine thermal lensing  Higher finesse put more severe constraints on the coating specification (e.g. reflectivity, asymmetry and uniformity)  Need to continue the R&D − R&D in progress all over the world − Virgo on the frontline − Several Virgo groups interested in pursuing coating research Adv LIGO Adv Virgo

29. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 29 INFRASTRUCTURES  Anthropogenic noise enters the Virgo noise budget. Big progress already done in understanding the coupling mechanisms.  AdV will be 10x as sensitive  NEED TO REDUCE THE NOISE  Possible solutions require infrastructure modifications

30. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 30 AdV BASELINE - SUMMARY heavier mirrors (42 kg) high finesse (≈1000) larger beam waist DC detection signal recycling new IP tilt control new payload fused silica suspensions high power SSL (200 W)

31. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 31 BNS range: 121 Mpc BBH range: 856 Mpc 1 kHz sens.: 6 10 -24 /√Hz SENSITIVITY CURVE - preliminary DESIGN PARAMETERS: − SR mirror transmittance: 0.04 − Input mirror transm: 0.007 − Finesse: 885 − PR factor: 23.5 − Power on BS: 2.9 kW Reference AdV sensitivity curve. Not a frozen optical design. Useful to start studying the impact of the various noise sources.

32. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 32 TWO-STEP STRATEGY? We are considering the idea of a two-step strategy: − Start AdV WITHOUT SR mirror and learn to operate the power recycled interferometer with high power − Add the SR mirror afterwards  A good “intermediate” sensitivity can be achieved, even better with heavier mirrors Power rec AdV BNS range: 97 Mpc BBH range: 265 Mpc 1 kHz sens.: 2 10 -23 Dual rec AdV BNS range: 121 Mpc BBH range: 859 Mpc 1 kHz sens.: 6 10 -24

33. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 33  SCIENCE and INTERNATIONAL CONTEXT  AdV BASELINE DESIGN  ORGANIZATION AND COST

34. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 34 AdV NEXT STEPS VACVacuum SATSuperattenuators PAYPayload MIRMirrors TCSThermal compensation LASLaser INJInjection system DETDetection system OSDOptical simulation and design ISCInterferometer sensing and control DAQElectronics, software and data acquisition DAMData management IMEInfrastructure modifications for env. noise reduction 1. Realization of the Conceptual Design and PEP 2006-07 2. Realization of the Technical Design 2008-2009 3. Completion of R&D and procurement of the parts2009-11 4. Assembly and integration2011-12  Early 2008: appointment of the SMs  Mid 2008: subsystem breakdown and work plans  Fall 2008: first AdV review − to review the subsystems plans and activities − to take a final decision on the open options with the biggest impact on the design

35. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 35 AdV BASELINE COST SUBSYSTEMESTIMATED COST (k€) VAC960 SAT1105 PAY720 MIR4100 TCS335 LAS550 INJ630 DET270 DAQ420 IME1060 TOTAL10150 +30% contingency13195 +20% taxes15834  Not included so far: − expenses for labor/travels − expenses for computing & data analysis − escalation factor  The open options might change the overall cost − e.g.: the cost of the mirrors can be 1.5x if the 60 kg option is selected  A more refined cost model will be possible when the subsystem plans will be ready

36. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 36 COMPUTING (PRELIMINARY)  Online computing at EGO: AdV sensitivity just scaled with respect to Virgo, therefore similar costs can be estimated, satisfied with O(100) computing nodes  Offline requests: larger in the Adv LIGO-AdV era because of − wider band of Adv LIGO with respect to LIGO − extra costs due to the network analysis, including Monte Carlo.  Exact estimation difficult at the moment. In the ball park of 10 TFlop/s to perform analysis roughly in the same time as acquisition.

37. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 37 CONCLUSIVE REMARKS  A baseline design and a preliminary execution plan for AdV have been presented (CSN2, STAC and EGO Council)  Possible changes to the baseline will be considered (on the strength of the R&D progress) and discussed next year within a new AdV organization  More R&D/prototyping is needed. Funding has been frozen by the Council, reason of concern  Management structure being setup. Moving towards the technical design We need AdV to stay in the GW network when the science will start!

38. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 38 FROM THE STAC REPORT  The question is not: "if" but "how one should build AdV?"  The STAC welcomes the reorganization of AdV effort into a project-oriented system with identified subsystems and subsystem managers.  The presented baseline is a description base of a proposal good enough to constitute a starting point for a more detailed proposal.  The STAC is worried about the news about planned cuts in EGO funding and strongly suggests restoring funding in order to reduce the risks in the evolution of the instrument.

39. advanced CSN2 – Roma, Jan. 30th, 2008 G.Losurdo – INFN Firenze 39 FROM THE COUNCIL REPORT  The Council (…) recognizes the importance of the AdV program which will allow entering into the domain of gravitational wave astronomy.  The Council supports the AdV project and takes note of the proposed milestones. Adding new collaborators would certainly make the funding easier and this should be actively pursued. The Council also took note of the need to involve the funding Institutions in order that a decision on its funding be taken timely as the work plan indicates and as needed to have AdV operative at the same time as Advanced LIGO.