Advanced Virgo BASELINE DESIGN

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1 advanced Advanced Virgo BASELINE DESIGN Giovanni Losurdo INFN Firenze Advanced Virgo Coordinator for the Virgo Collaboration

2 ADVANCED VIRGO (AdV) Upgrade of Virgo+, minor modifications to the facilities and to the SA Sensitivity goal: about 10x better than Virgo Main foreseen changes: higher power (optical readout noise) heavier mirrors (optical readout noise) better coatings (thermal noise) signal recycling (shape the curve) beam waist position (thermal noise) ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 2

3 ONGOING AdV R&D SUMMARY (I) Mirror coating Mirror cleaning Fiber laser and IMC New modal optics Optical config. design (Post ham) Prototyping/locking (CALVA) Optics for high power Detection system ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 3

4 ONGOING AdV R&D SUMMARY (II) Tiltmeter IP upgrade Marionette RM Cleanliness Ribbons for monolithic susp. (Glasgow) Electrostatic act. ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 4

5 STATUS AdV conceptual design completed Internal review in progress Due to STAC (advisory panel) and EGO Council (funding agencies) by the end of the month Waiting for the funding agencies approval New organization being setup. From Working Groups to WBS. Next two years to prepare the AdV technical design. ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 5

6 AdV BASELINE

7 LASER BASELINE: 200 W SOLID STATE LASER AMPLIFIER (LZH for Advanced LIGO) Nice Group is already collaborating with LZH for the Virgo+ amplifier. ALTERNATIVE OPTION: FIBER LASER AMPLIFIER (R&D Nice Limoges): promising research line stabilization to be done non linear effects and polarisation maintaining to be investigated at HP ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 7

8 INPUT OPTICS BASELINE: 144 m SUSPENDED RESONANT IMC: Virgo like solution. Problem of small angle diffused light to be addressed. EOM FARADAY: Advanced LIGO solution. ALTERNATIVE OPTION: AdvLIGO Faraday FIBER LASER IMC (R&D Nice Limoges): promising research line, would be a major simplification. AdvLIGO EOM ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 8

9 SIGNAL RECYCLING BASELINE: WIDEBAND SR Optical parameters to be defined. The base for the SR tower is there! ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 9

10 OPTICAL LAYOUT DETECTION OPT. LAYOUT BASELINE: TEM 00 WAIST IN THE CAVITY CENTER LARGER BEAM: requires changing the vacuum links in the central area. see talk by A.Freise DET. BASELINE: PHOTODIODES IN VACUUM DC DETECTION ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 10

11 MIRRORS BASELINE: 35 cm diam. 20 cm thick, 42 Kg SUBSTRATES STATE OF ART COATINGS ALTERNATIVE OPTION: EVEN HEAVIER TEST MASSES (60 Kg?) Useful if fiber geometry is optimized ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 11

12 SUPERATTENUATOR IP BASELINE: VIRGO DESIGN with STIFFER IP LEGS TILTMETER AND IP 6 DOF CONTROL MECHANICS: NEW MARIONETTE REFERENCE MASS MIRROR ACTUATION: COIL MAGNET PAIRS ALTERNATIVE OPTION: ELECTROSTATIC ACTUATORS: noise specs to be demonstrated ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 12

13 SUSPENSIONS BASELINE: FUSED SILICA CYLINDRICAL FIBERS ALTERNATIVE OPTION: FUSED SILICA RIBBONS DUMBBELL FIBERS Virgo+ studies: The dummy mirror suspended with silica fibers ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 13

14 AdV BASELINE SUMMARY heavier mirrors (42 kg) new IP tilt control high finesse ( 1000) larger beam waist signal recycling new payload fused silica suspensions high power SSL (200 W) DC detection ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 14

15 SENSITIVITY CURVE preliminary BNS range: 121 Mpc BBH range: 856 Mpc 1 khz sens.: SR mirror transmittance: 0.04 Input mirror transm: Finesse: 885 PR factor: 23.5 Power on BS: 2.9 kw ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 15

16 BNS/BBH inspiral range vs t IN t SR Lower FP cavity finesse t SR t IN Lower SR mirror transmittance BLUE = BNS inspiral range RED = BBH inspiral range ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 16

17 AdV sensitivity vs Fiber geometry The ribbon choice reduces considerably the contribution of suspensions thermal noise Dumbbell fibers can also improve the performance The benefits on the sensitivity are limited by radiation pressure, newtonian and CONTROL NOISE (unmodelled so far) fiber geometry Finesse cylindrical 885 ribbon G 23.5 P BS 2.9 kw BNS BBH ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 17

18 HEAVIER MIRRORS? If ribbons are used, low frequency sensitivity can be further improved by using thicker mirrors (30 cm diam., 63 kg mass) The low frequency sensitivity is then limited by newtonian noise (model uncertain) and coating brownian noise fiber geometry BASELINE ribbon 63 Kg mirr Finesse 885 G 23.5 P BS 2.9 kw BNS BBH ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 18

19 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.: ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 19

20 CONCLUSION A baseline design for AdV has been proposed 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 See next talk by A.Freise and P.Puppo for more details ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 20

21 INVITATION AdV is moving towards a new phase: the preparation of the TECHNICAL DESIGN There are many things to do and we are open to enlarge the Collaboration for Advanced Virgo ILIAS Annual Meeting Tubingen, Oct 9, 2007 G.Losurdo INFN Firenze 21