VIRGO Second part

Advanced VIRGO and the INFN VIRGO activity in 2010 Fulvio Ricci

OPENING A NEW ASTRONOMICAL WINDOW 10 8 ly Enhanced LIGO/Virgo 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, GEO HF

ACHIEVABLE SENSITIVITY NS-NS detectable as far as 300 Mpc BH-BH detectable at cosmological distances 10s to 100s of events/year expected!

Ad Virgo in a nutshell 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) Larger central vacuum links Large cryotraps

MAIN PROJECT MILESTONES  Oct 09: AdV project start  Jun 10: Release of the Technical Design Report  Jul 11: Virgo+ shutdown / start AdV installation  Mar 14: End of Sub-Sytem pre-commissioning and first light injection in the arms  Dec 14: AdV project end: first 1 hour lock 6

MIRRORS First important orders ready Robot: reviewed and approved Technical Readiness Review of mirror substrates under way. Substrates: – Offer received – Order to be placed after the formal approval (Oct 6) Polishing to start in the second half of

Vacuum after the mirror production the vacuum system is on the critical path of the project First cryo-trap ready in factory (proto)Nov ’10 Comment: first trap will be fully tested in factory. The production of the remaining three will follow Towers displaced in new positionsFeb ’12 Comment: it shall be done early after the stop, constraining all the other activities in the central hall Enlarged links installedMay ’12 Comment: central vacuum chamber completed Control system installation startJun ’12 The 4 traps installed Nov ’12 Comment: traps in vacuum at 77K, both tube arms available

How we will use the budget for the Adv VIRGO construction: 2009 ORDERS 9 Foreseen expenditures: ≈2.8 ME PS - Subject to formal approval of the project by the Council…

CRUCIAL POINTS STILL OPEN  After formal approval: put baseline and related documents under configuration control –Configuration control board not yet in place  Optical design finalization  Impact of Non Degenerate Recycling Cavity on Payload structure (suspension for multi-mirrors)  TCS finalization (compensation plate ) and impact on the input mirror payloads  Assessment of fiber laser progress (review in October or early November) 10

Cryotraps and noise study: the present VIRGO lesson Bubble noise from cryotrap – When refilled, boiling liquid nitrogen shakes the cryotrap and introduces noise through diffused light – Noise reduces with time constant of about 1 day – Cryotrap refill level reduced to reduce the excess of noise.

12 Optical Design Study Moving from principle to technical design Main open issues: – non degenerate recycling cavities: we are studying the impact on the infrastructure and the solutions to suspend the extra mirrors – thermal compensation: we have to assess the efficiency of the proposed solution and the impact on the payload dynamics

13 Thermo Compensation System for Adv Virgo Red dots: shielded heating ring Green rays: CO 2 heating beams Blue rays: sensing beams Compensation plates will correct thermal effects in the SRC Shielded heating rings will compensate HR surface deformations Hartmann sensors will be used to monitor TM and CP phase profile In the case of Advanced Virgo, The positioning of CPs in the PRC is a delicate issue due to its strong impact with the suspension systems and it will have to be investigated in collaboration with the other involved Subsystems LIGO approach and reference solution for Adv VIrgo

The Ad VIRGO payloads Mirrors with double mass 20 k  40 kg - New fibers - New bonding and improved diagnostic Critical payloads in the present OSD reference solution : a) FP input mirror payload should include the compensation plate Danger: - spoiling the low acoustic dissipation of the suspension - increasing the control system complexity b) Beam splitter payload: two extra mirror to be suspended in the beam splitter tower Requirements: - seismic and acoustic attenuation - low thermal noise contribution - alignment control -diffused light reduction Main difficulty: lack of space in the tower The conceptual study and the simulation is started already. Prototypes are required to finalize the Technical Design

SUPERATTENUATOR  Tiltmeter PZT THE CASE FOR IMPROVED CONTROL − Virgo inertial platform controlled in 4 d.o.f. − Wind induced ground tilt proved to be a problem − AdV: implement tilt control (6 dof) − PZT useful on the short towers also to increase the vertical attenuation

A full scale superattenuator is under to test the 6 dof control strategy New Inverted Pendulum (IP) legs (monolithic). Installation of the piezo actuators. Tilt meter and in general new sensor test The facility can host later the new payload prototype The SAFE facility Cascina The experimental West arm Safety structure + I.P. I.P + Intermed.f ilters + Payoload

Summary of highest priorities for the 2010 INFN-VIRGO request Support for our development activity for completing the technical design of Ad Virgo Support for the data analysis activity on the VSR2 collected data Support our mission on site (M.I.) Support our collaboration with LIGO on DA (M.E.) All our requests are not included in the Ad VIRGO construction budget and are not supported by the EGO budget!

The Internal Mission Justification We checked that we have a mean value of 25 INFN-FTE on site during the 225 working days of the year - 15 from Pisa (25 € /day including travel exp. ) - 10 from the other INFN section (150 € /day including travel exp. ) 225*(25* *150 ) = € We need also to support the interaction among the italian groups ( accel. and phase cam.: Pd/Trento/Legnaro/Pi/Na, pay act.: FI/Urb –Pg-Rm1, suspen. Tilt: Pi-Tov, coat. Ge-Pg-Fi/Ur/Tn) Without the INFN man power VIRGO is dead !

2010 MILESTONES reported on the INFN –web page  : Construction start of the cryotrap protype  : Realease of the Final Technical Design for Adv.VIRGO  : Start of the mirror superpolishing 19

END Thanks for your attention