Present SA performance vs. AdV & ET Specs S.Braccini for Virgo Suspension group

1. Present SA performance vs. AdV & ET SpecsS.Braccini for Virgo Suspension group

2. Passive Attenuation

4. 2 Hz Long Pendula Ground Resonances f-2N Transmission Frequency (Hz) Soft Springs Mirror

5. Magnetic Antisprings 8 m Blade Springs

6. Rumore Termico Ground Seismic Noise Mirror Seismic Noise

8. DL(f) = h(f) / 3000

9. TFmax = DL(f) /(LSD Ground Seismic Noise) LSD Ground Seismic Noise = 5 x 10 -7/ f 2

10. Same Exercise for ET sensitivity

11. DL(f) = h(f) / 10000

12. TFmax = DL(f) /(LSD Under-Ground Seismic Noise) LSD Ground Seismic Noise (Kamioka) - 5 x 10 -9/ f 2 (Duzel Mine much better)

13. Same Exercise for ET-Xylophone sensitivity

14. DL(f) = h(f) / 10000

15. TFmax = DL(f) /(LSD Ground Seismic Noise) LSD Ground Seismic Noise (Kamioka) - 5 x 10 -9/ f 2

16. Valid both for horizontal and vertical seismic noise

17. SA design e freccette Filter Chain TF measurements (without Pre-Isolator !)

18. SA design e freccette CITF Measurements around 2, 4, 9 Hz @ 4.1 Hz < 6 ×10e-8

19. SA design e freccette CITF Measurements around 2, 4, 9 Hz @ 2.25 Hz 5 ×10e-6

20. High Sens Range Larger stability allows longer measurements

21. Displacement (m .Hz-1/2) Transfer Function < 10-10 SA design e freccette Top frequency (Hz) Mirror

22. TF < 1.7 x 10-12 TOP 1.2 x 10-6m Hz-1/2 MIRROR Stressed Measurement T = 41943 s High Sens Range 2 x 10-18m Hz-1/2

23. TF = 1.26 x 10-11 ! !

24. AdV ET-Xylophone 1.26 x 10-11 + Pre-Isolator

25. SA design e freccette SA design e freccette Possible Bypass X-excitation

26. X - Excitation Results Bypass Indication ?

27. Red = Line Detected Blue = Line Not Detected Purple = Upper Limit not useful (too large)

28. Upper Limit Detected 53 113 AdV ET-Xylophone IP Guarantees for this ! Already compliant for ET (Remind that we are speaking of Upper Limits !) Without Pre-Isolator (Just filter chain !)

29. Vertical TF measurements (Coupling included in the measurement)

30. Vertical Measurements

31. Vertical Upper Limit Vertical Detected 60 AdV ET-Xylophone F0 Guarantees for this UPPER LIMIT (!) compliant for ET Without Filter Zero (Just filter chain !)

32. Preisolator makes safety margin wide in AdV

33. SA are compliant also for ET starting from 4 Hz.... What happens below?

34. HORIZONTAL @ 2.25 Hz 5 ×10e-6 Remarkable Attenuation also at 2.25 Hz

35. VERTICAL @ 2.25 Hz 1.5 ×10e-6 Remarkable Attenuation also at 2.25 Hz

36. Stage by Stage Measurement (and Model) TF Model Meas. No Maybe Yes 2 3 4 f

37. ET Design Programme Cut-off 3-4 Hz  No Design Study Cut-off 1-2 Hz  Design Study SCIENCE CASE & NEWTONIAN NOISE TO BE DISCUSSED AT ERICE MEETING

38. N  1 Hz     2 Hz ------------------------- {3, 1.6*10-7, 5.4*10-10}  {4, 4.8*10-8, 3.3*10-11}  {5, 2.6*10-8, 3.4*10-12}  {6, 2.3*10-8, 6.7*10-12}  {7, 2.1*10-8, 2.6*10-12} Optimized at 1Hz Courtesy G. Cella ~50 m Horizontal G.Cella

39. 2 Independent full simulations in progress

40. Actuation Noise

41. V V V V 0.2 0.2 Magnete Bobina -0.2 -0.2 Lunghezza cavità l/100 Locking

43. M g PendoloInvertito GiuntoFlessibile 30 mHz

44. Accelerometers RESIDUAL SWING < 0.1 mm DSP DAC Actuators ADC

45. Motors Sensors Coil Drivers Sensors Coil Drivers Sensors Coil Drivers Superattenuatore • Acc. Sens: • -10-9 m/s2 • 0 – 100Hz • f.s. 1g Control Electronics System Position & Damping • DSP: • 96 bit • - 60 MFLOPs • DAC: • -8 Chan. • 20 bit • 500 KHz • ADC: • -8 Chan. • 16 bit SAR • - 200 KHz

46. Hierarchical Control

47. MIRRORACTUATION WIND SEA

48. Tilt

49. Direct Measurement on the ITF !! A.Gennai (VIR 029-A09)

50. Distribution and (its integral) of the maximum of the absolute values of marionetta correction voltage computed on 200 s-long interval (all VSR1 run, itf in science mode)