1. 1 Virgo commissioning status M.Barsuglia LAL Orsay

2. 2 BS The central interferometer Test of the technical choices during end of the construction Spring 2001- Summer 2002 Acquire experience (no prototype in the Virgo community)

3. 3 Suspensions long term operation, robustness. direct measurement of the attenuation at 4 Hz hierarchical control (top stage, reference mass) Digital controls local controls, control of SA resonances, lock acquisition, WFS Output mode-cleaner locking, contrast improvement Local controls Technical choice validation

4. 4 Top stage Last stage Seismic filters Suspension system

5. 5 Detection system

6. 6 OMC locking Transmitted power  signal TEM 00

7. 7 CITF sensitivity during e-runs Sept 2001 July 2002 Alignment control Frequency noise

8. 8 Lock robustness during e-runs E0 1 98% ~ 51 h E1 1 85% ~ 27 h E2 3 98% ~ 41 h E3 4 98% ~ 40 h E4 4 73% ~ 14 h Run #losses duty cycle longest lock ITF stored power ~ 200 W

9. 9 July 2002  September 2003: Upgrade to Virgo mirrors installation arm completion, vacuum ITF upgrades (mode-cleaner, local controls, …) September 2003: Virgo commissioning

10. 10 North arm Lock acquisition output mode-cleaner 3-days engineering run frequency stabilization WFS hierarchical control (top stage, marionetta, reference mass) West arm Recombined ITF full ITF Commissioning plan

11. 11 Interferometer operation: shifts Morning Shift (8h-15h) Evening Shift (16h-23h) Task #2Task #1 1 Interferometer operator 1 Computer operator 1 Interferometer coordinator 1-3 People working on commissioning task #1 1-3 People working on commissioning task #2 Daily meeting (15h-16h) 2 8-hours shifts during commissioning 2 tasks in parallel

12. 12 North cavity locking scheme BS PR ~ 6 W angular control (pitch, yaw) no longitudinal damping 50 Hz BW, digital control Hz |Gain| frequency 1 pole at 0.01 Hz 2 zeros at 10 Hz 2 poles at 800 Hz 1 pole at 1000 Hz

13. 13 Linearized error signal No Linearized error signal m Lock acquisition speed threshold ~ 10 m/s Signals and simulation CorrectionTransmitted P Time domain Simulation (Siesta)

14. 14 locking Locking at the first trial first lock ~ 1 hour frequency noise Transmitted power Frequency noise reduction

15. 15 Lock acquisition statistics with the linearized error signal  24 locking events collected locking and delocking the cavity  23 lock acquisition at the first attempt, only 1 failed locking attempt

16. 16 Relative velocity between the mirrors computed for each locking attempt 8  m/s: maximum velocity for the lock acquisition success 12.5  m/s: velocity of the failed event Failed locking attempt v ~ 12.5 8 2.5  m/s: mean value of the velocity Lock acquisition statistics

17. 17 Output mode-cleaner locking Transmitted P Reflected P  2 StateTemperatureError signal 2 min

18. 18 Output mode-cleaner locking -II 1. Cavity locked with ~ 1% of the light 2. Mode-cleaner locked 3. Control transferred to this phd ~ 99% of the light After OMC Before OMC Sensitivity (m/  Hz)

19. 19 Shot noise Electronic noise (ADC) Frequency noise Control noise ? MC length control noise North cavity noise budget

20. 20 laser 50 Hz 300 kHz Ref Cav 50 Hz

21. 21 Transmitted P during C1 run tests Seismic Noise problem 3 days 14-17 november 2 Long locks

22. 22 large seismic noise during the run @300 mHz (microseismic peak) new inertial control scheme “less inertial” marionetta roll resonance at 300 mHz excited new local controls: sensing coupling roll  yaw Seismic noise problem solution found  new inertial damping filter, in test.

23. 23 Tidals during C1 run 50 m Correction sent to the end test mass

24. 24 North arm Lock acquisition output mode-cleaner 3-days engineering run frequency stabilization WFS hierarchical control West arm Recombined ITF full ITF Commissioning plan

25. 25 laser 50 Hz 300 kHz Ref Cav 50 Hz Frequency stabilization

26. 26 laser 50 Hz 10 kHz 300 kHz Ref Cav 50 Hz 3 actions: - unlock reference cavity - change IMC curved mirror locking point - open second stage of frequency stabilization Frequency stabilization

27. 27 laser 50 Hz 20 kHz. 300 kHz Ref Cav 1 Hz Frequency stabilization Last step: DC control of laser frequency

28. 28 Frequency stabilization: first tests Cavity trans P Test mass corr 2nd stage ON Cavity err sig 2nd stage ON Cavity corr OFF switch oscillations simulink model

29. 29 WFS control matrix optical matrix measured filter ready

30. 30 WSF control

31. 31 WFS control matrix optical matrix measured filter ready will be tested in early january transition from local controls  WSF control

32. 32 2 nd (west) arm locking Transmitted power Error signal cavity locked in a stable way yesterday same algorithm, same filter of north cavity preliminary analysis of 2 cavities optical properties

33. 33 North arm lock acquisition output mode-cleaner 3-days engineering run frequency stabilization WFS hierarchical control (top stage, marionetta, reference mass) West arm Recombined ITF full ITF Commissioning plan

34. 34 Hierarchical control: 3 points

35. 35 Fast corrections (f > 70 mHz) Slow corrections (f < 70 mHz) 3.5 mN Force applied to mirror No feedback to top stage with feedback to top stage Hierarchical control: top stage Done during the CITF commissioning

36. 36 Hierarchical control: marionetta acquire the lock with the reference mass move the control to the marionetta  DAC noise reduction complicated transfer function  simulations

37. 37 North arm Lock acquisition output mode-cleaner 3-days engineering run frequency stabilization WFS hierarchical control West arm Recombined ITF (january) full ITF Commissioning plan

38. 38 Recombined ITF B7 B1p B2B2 B8B8 north arm west arm B5B5 start noise analysis ~ 250 mW

39. 39 Lock acquisition B7 B1p B2B2 B8B8 B5B5 Step 1: lock north arm using pick-off 5 Done Step 2: lock west and mich

40. 40 Recombined ITF: simulation Trigger north satisfied north cavity locked Trigger west&mic satisfied west cavity lockedmic locked Acq_north ONAcq_west_mic ON

41. 41 North arm Locking, output mode-cleaner (done) 3-days engineering run frequency stabilization, WFS (in progress) hierarchical control (top stage, marionetta, reference mass) West arm (in progress) Recombined ITF (january) full ITF Commissioning plan

42. 42 Lock acquisition LIGO method Time-Domain simulation (Siesta) Now transition 3  4 Lock acquisition for full ITF State 2 locked State 3 locked

43. 43 North arm Lock acquisition (done) output mode-cleaner (done) 3-days engineering run (done) frequency stabilization (in progress) WFS (in progress) hierarchical control (january) West arm (done) Recombined ITF (starts december 29 th ) full ITF (?) Science (?) Summary