Advanced Virgo Giovanni Losurdo Advanced Virgo Coordinator for

Advanced Virgo Giovanni Losurdo Advanced Virgo Coordinator for the Virgo Collaboration

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

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

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

STEPS TOWARDS TARGET q 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 q Even with low input power and without SR Ad. V can have a relevant science impact BNS (Mpc) BBH (Mpc) h@1 k. Hz Ad. V REF 149 753 1. 8 e-23 5 W in 117 1374 1. 8 e-21 30 W in 139 1004 1. 6 e-22 no SR 107 311 2. 2 e-23 Ad. V 1 st Project Review – Cascina, Nov. 3 rd, 2008 G. Losurdo – Ad. V Coordinator 5

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

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

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

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

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

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

INJECTION SYSTEM q Input mode cleaner: 144 m suspended triangular cavity q Large Faraday isolator with thermal compensation (DKDP crystal) q 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 Ad. V 1 st Project Review – Cascina, Nov. 3 rd, 2008 G. Losurdo – Ad. V Coordinator 12

MIRRORS HEAVIER TEST MASSES q WHY? Cope with larger radiation pressure q Require payload modification and silica fibers optimization q 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 q Corrective coating might allow to further improve the flatness and give more flexibility q 63 kg mirrors considered − technically feasible, though payload modifications more risky − science gain limited by newtonian/susp thermal noises Ad. V 1 st Project Review – Cascina, Nov. 3 rd, 2008 G. Losurdo – Ad. V Coordinator 13

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 Ad. V 1 st Project Review – Cascina, Nov. 3 rd, 2008 G. Losurdo – Ad. V Coordinator 14

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 Ad. V 1 st Project Review – Cascina, Nov. 3 rd, 2008 G. Losurdo – Ad. V Coordinator 15

THERMAL COMPENSATION q WHY? Compensate for wavefront distorsion and test mass surface deformation q 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 q Compensation plates to be suspended from SA Ad. V 1 st Project Review – Cascina, Nov. 3 rd, 2008 G. Losurdo – Ad. V Coordinator 16

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

SENSING AND CONTROL q 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 q The reference control strategy requires to move all the long towers in the central building Ad. V 1 st Project Review – Cascina, Nov. 3 rd, 2008 G. Losurdo – Ad. V Coordinator 18

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

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

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

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

VACUUM – CENTRAL LINKS NEW VACUUM LINKS IN THE CENTRAL AREA q 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 Ad. V 1 st Project Review – Cascina, Nov. 3 rd, 2008 G. Losurdo – Ad. V Coordinator 23

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

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

ORGANIZATION

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

PHASE 2 ORGANIZATION Virgo spokesman/ EGO scientific dir. EGO VSC Ad. V coordinator – G. Losurdo OSD – A. Freise ISC – F. Bondu LAS – N. Man INJ – 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 Task Manager … Ad. V 1 st Project Review – Cascina, Nov. 3 rd, 2008 G. Losurdo – Ad. V Coordinator 28

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

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 Ad. V documents, and work out the task breakdown. Ad. V 1 st Project Review – Cascina, Nov. 3 rd, 2008 G. Losurdo – Ad. V Coordinator 30

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

Ad. V COST q In fall 2007 the Ad. V cost was estimated in the “Ad. V PEP” (VIR-043 A-07) 15. 8 MEuro (equipment only) q Since then: − New organization, subsystem managers in charge − Relevant changes to the conceptual design q Some of the new design choices may have an important impact on the overall cost (non-degenerate cavities, anthropogenic noise reduction, need for bakeout, …) q Each SM is working to provide an accurate cost plan in the next months (some already have one). The Ad. V cost plan and spending profile will be presented before the spring review. Ad. V 1 st Project Review – Cascina, Nov. 3 rd, 2008 G. Losurdo – Ad. V Coordinator 32

DRAFT PLANNING 07 08 09 10 PHASE 1: Ad. V conceptual design 11 12 13 14 15 16 PHASE 3: Ad. V construction PHASE 2: Ad. V final design × place mirrors order PHASE 4: Ad. V installation Commissioning Ad. L: 1 st ITF accepted Ad. L: 2 nd ITF accepted Ad. L: 3 rd ITF accepted Ad. V 1 st Project Review – Cascina, Nov. 3 rd, 2008 G. Losurdo – Ad. V Coordinator 33

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