1. Advanced Virgo Giovanni Losurdo Advanced Virgo Coordinator for the Virgo Collaboration

2. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 2 ADVANCED VIRGO (AdV) PROJECT GOALS  Upgrade Virgo to a 2 nd generation detector. Sensitivity: 10x better than Virgo  Be part of the 2 nd generation GW detectors network. Timeline: in data taking with Advanced LIGO

3. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 3 MAIN REQUIRED UPGRADES Signal Recycling (SR) Non degenerate rec. cavities 200W laser Higher finesse 3km FP cavities Heavier mirrors Waist in the cavity center Larger central links Cryotraps Monolithic suspensions

4. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 4 TUNEABILITY  AdV can be “tuned”. Changing the SR mirror transmittance allows to shape the sensitivity curve  The tuneability can be exploited to optimize the detector for different astrophysical sources (BNS, BBH, millisecond pulsars,supernovae)

5. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 5 STEPS TOWARDS TARGET  The design sensitivity will be achieved in “steps”: − The commissioning activity will start in “low power” configuration − The opportunity of starting without SR will be considered  Even with low input power and without SR AdV can have a relevant science impact BNS (Mpc)BBH (Mpc)h@1 kHz AdV REF1497531.8e-23 5 W in11713741.8e-21 30 W in13910041.6e-22 no SR1073112.2e-23

6. DESIGN OVERVIEW See “Advanced Virgo Preliminary Design”, VIR-089A-08

7. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 7 OPTICAL CONFIGURATION MAIN FEATURES  Signal recycling  Non degenerate recycling cavities  Larger spot on the mirrors

8. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 8 OPTICAL CONFIGURATION - SR SIGNAL RECYCLING  WHY?: Allows shaping of the detector sensitivity  Requires one more SA (tower base available)  Adds complexity, commissioning more difficult

9. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 9 OPTICAL CONFIGURATION -NDRC NON DEGENERATE RECYCLING CAVITY  WHY?: Avoid high order modes to be resonant − much “cleaner” ITF dynamics − reduces sensitivity to misalignments, thermal effects, ROC errors − provides more control signals  Requires: − larger vacuum links − extra seismic isolation for injection and detection benches  Promises to simplify commissioning

10. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 10 OPTICAL CONFIGURATION – SPOT SIZE LARGER SPOT SIZE  WHY?: Reduces mirror thermal noise and thermal effects on input mirrors  Requires larger vacuum links and larger beam splitter

11. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 11 PRE-STABILIZED LASER  AdV laser to provide up to 200 W  High power stage bases on the LZH design for the Adv LIGO laser  Pre-stabilized in frequency and amplitude

12. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 12 INJECTION SYSTEM  Input mode cleaner: 144 m suspended triangular cavity  Large Faraday isolator with thermal compensation (DKDP crystal)  Non degenerate PR cavity: the matching telescope is moved inside the cavity. The PRM and the folding mirror must be suspended on the injection bench

13. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 13 MIRRORS HEAVIER TEST MASSES  WHY? Cope with larger radiation pressure  Require payload modification and silica fibers optimization  Reference design: − 35 cm Ø, 20 cm thick, 42 Kg FP mirrors − Flatness requirements: 0.5 nm − Larger BS − 2010 state of the art coating  Corrective coating might allow to further improve the flatness and give more flexibility  63 kg mirrors considered − technically feasible, though payload modifications more risky − science gain limited by newtonian/susp thermal noises

14. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 14 MIRRORS - FEATURES All the choices needed to purchase the large test masses have been made. Some features of the small mirrors of the REC cavities TBD/TBC

15. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 15 MIRRORS - PRODUCTION PLAN Detailed revised DRAFT Planning if starting on 01/07/2009: estimation based on real delay for the manufacturing of the silica and on the real time necessary for the VIRGO+ substrates polishing Overall estimated time: 2 yrs + 9 mts

16. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 16 THERMAL COMPENSATION  WHY? Compensate for wavefront distorsion and test mass surface deformation  Reference design: − Ring heater around test masses to correct for ROC − CO 2 laser to correct for wavefront distorsion on recycling cavities − “Compensation plates” needed in front of input test masses  Compensation plates to be suspended from SA

17. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 17 DETECTION DC READOUT  WHY? To reduce shot noise by ~20% and the influence of some technical noises  Requires a new high finesse output mode cleaner SUSPENDED DETECTION BENCH  Must host the SR mirror and the folding mirror (with their suspensions)  Must host the main photodiodes that need to be under vacuum

18. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 18 SENSING AND CONTROL  Reference design: − Auxiliary laser to lock the high finesse cavities − Extended Variable Finesse technique for full lock − Requirements, a set of cavity lengths and mod. frequencies defined − Linear control scheme defined  The reference control strategy requires to move all the long towers in the central building

19. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 19 SUPERATTENUATOR  Vibration isolation provided by the SA is compliant with AdV sensitivity  Main foreseen change: tilt control of the inverted pendulum (inertial platform controlled in 6 d.o.f.)  Tilt control allows to cope with wind generated tilt noise, that can spoil the inertial damping performance with bad weather conditions  Tilt actuation already foreseen in the inverted pendulum design (room for PZT at the base of the legs)

20. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 20 PAYLOAD  The heavier mirror requires to modify the payload  Constraints: − keep the payload weight the same as Virgo’s − low electrical conductivity reference mass  A simplification of the “steering” part is being investigated (MRM)

21. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 21 MONOLITHIC SUSPENSIONS Virgo+ fibers  Engineering of Virgo+ fibers well advanced: − standardized production and reproducible geometry − welding and clamping optimized − flexure points controlled  AdV monolithic suspensions − fiber geometry optimization: use of tapered fibers?

22. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 22 VACUUM – RESIDUAL PRESSURE VIRGO RESIDUAL PRESSURE:  10 -7 mbar (H 2 O+H 2 +HC), 100 worse than LIGO (bake-out)  Residual pressure noise would spoil AdV sensitivity: bake-out needed  Need to separate tubes from towers REFERENCE SOLUTION: CRYOTRAPS  WHY? Allow to bakeout the pipes and not the towers  Major upgrade of the vacuum system

23. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 23 VACUUM – CENTRAL LINKS NEW VACUUM LINKS IN THE CENTRAL AREA  WHY?: lenghts to be changed, diameter to be increased − the position of the towers will be changed by up to 1 m (ISC requirements) − larger beam spot on the input test masses, folded beam path in non-degenerate recycling cavities, require larger diameter links

24. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 24 VACUUM - INFRASTRUCTURES STRUCTURES INVOLVED IN HEAVY MODIFICATION WORKS  vacuum links  scaffoldings braces  cable trays  clean air ducts of the towers  H beams as links between the frames of the ovens  false ceiling of the CR Towers Gallery DISPLACEMENT OF THE TOWERS IN THE CENTRAL HALL TO OPTIMIZE THE ITF CONTROL STRATEGY

25. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 25 INFRASTRUCTURES  Virgo sensitivity is spoiled by machine noise. Hard commissioning/detector work has been done to understand and reduce the couplings  AdV will be 10x as sensitive  noise reduction required  AdV approach: improve the machines isolation and move them far from the experimental halls

26. ORGANIZATION

27. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 27 AdV STEPS  PHASE 1: AdV Conceptual Design (ended fall 07)  PHASE 2: AdV Final Design (to end June 09)  PHASE 3: AdV Construction  PHASE 4: AdV Installation  PHASE 5: AdV Commissioning

28. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 28 PHASE 2 ORGANIZATION AdV coordinator – G.Losurdo OSD – A.Freise Task Manager … ISC – F.Bondu LAS – N.ManINJ – E.Genin DET – E.Tournefier MIR – L.Pinard TCS – V.Fafone SAT – R.Passaquieti PAY – P.Rapagnani DAQ – R.De Rosa VAC – A.PAsqualetti IME – A.Paoli VSC Virgo spokesman/ EGO scientific dir. EGO

29. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 29 Advanced Virgo Coordinator From the Virgo Organization Document  The AdV coordinator coordinates the preparation for AdV. More specifically he is responsible of: − Coordinating the activity of the AdV System Managers (SM) − Coordinating the R&D activity for AdV. − Coordinating the elaboration of the final design. − Making sure that system design issues are worked out.  His goal is to reach a state where the AdV systems are ready for construction (mandate to end in Spring 09)

30. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 30 Subsystem Managers OSD(Optical Simulation and Design)A. Freise(B’ham Univ.) ISC(Interf. Sensing and Control)F.Bondu(OCA Nice) LAS(Laser)N. Man(OCA Nice) INJ(Injection system)E. Genin(EGO) DET(Detection system)E. Tournefier(LAPP Annecy) MIR(Mirrors)L. Pinard(LMA Lyon) TCS(Thermal Comp. System)V. Fafone(INFN Rome 2) SAT(Superattenuators)R. Passaquieti(INFN Pisa) PAY(Payload)P. Rapagnani(INFN Rome) DAQ(Data Acq. and Electronics)R. De Rosa(INFN Naples) VAC(Vacuum)A. Pasqualetti(EGO) IME(Infrastructures)A. Paoli (EGO) The SM are responsible, within their subsystem, for: − preparing the list of tasks, milestones and deliverables − producing precise requirements/specifications; − preparing the case for the selection of the open design options, including detailed planning and financial resources required; − preparing a design and project execution plan, to be integrated in the updated AdV documents, and work out the task breakdown.

31. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 31 NEXT STEPS If project approved and funded: Start Phase 3 placing the order for the mirrors on July 2009 GOALS FOR MAY 09 (NEXT PROJECT REVIEW) 1. Release of the AdV final design 2. Updated cost plan and project execution plan

32. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 32 AdV COST  In fall 2007 the AdV cost was estimated in the “AdV PEP” (VIR-043A-07) 15.8 MEuro (equipment only)  Since then: − New organization, subsystem managers in charge − Relevant changes to the conceptual design  Some of the new design choices may have an important impact on the overall cost (non-degenerate cavities, anthropogenic noise reduction, need for bakeout, …)  Each SM is working to provide an accurate cost plan in the next months (some already have one). The AdV cost plan and spending profile will be presented before the spring review.

33. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 33 AdL: 2nd ITF accepted DRAFT PLANNING 08091011121314151607 PHASE 1: AdV conceptual design PHASE 2: AdV final design PHASE 3: AdV construction PHASE 4: AdV installation Commissioning AdL: 1st ITF accepted AdL: 3rd ITF accepted × place mirrors order

34. AdV 1st Project Review – Cascina, Nov. 3rd, 2008 G.Losurdo – AdV Coordinator 34 CONCLUSIVE REMARKS  A preliminary design of AdV has been released  The forthcoming talks by the subsystem managers will detail the status of the design and show the important progress achieved in the next months  The Virgo Collaboration will release the AdV final design and the updated cost plan before the spring 09 review  GOAL: being in the position to start the construction of AdV on July 1st 2009