1. Virgo Commissioning: Status and Plans October 24th 2005 Matteo Barsuglia, LAL/CNRS

2. Status at the Prague meeting
Interferometer in the recycled (full) configuration with 0.7 W (reduced power)
Last data taking: C5 (dec 2004, 5 days)
Main commissioning activities: interferometer control set-up and tuning
Linear alignment
Hierarchical control
Automation
Problems of interferometer bistabilities

3. Reduced power: motivations
Laser Frequency (Hz)
fringes
Short term solution: put attenuator between the IMC and the ITF
 Power attenuated (8 W0.8 W)

4. Final solution: Faraday isolator and new bench
Brewster dielectric polarizers
Rotator
Installation of the new bench on going

5. C5 sensitivity (Dec 2004) Recycled interferometer 0.8 W input power
Typical locking time: 1 hour

6. The interferometer bistabilities
Present continuously since january 2005
Interferometer internal power (a.u.)
Continuous interferometer unlocks
No science operations
No standard commissioning work
Problem solved in july 2005 with:
1. Better photodiode centering
2. Special alignment of the injection bench
3. Special tuning of a demodulation phase of a signal involved in the interfererometer control
The effects 2,3 can be explained with a presence of spurious beams, stray light, or beam clipping at the injection bench level
Actions taken for the new injection bench
1 sec

7. Last months summary Problem of bistabilities solved
Automatic alignment completed
Hierarchical control completed
First phase of detector automation completed
Progress in noise hunting
Two data taking (C6 14 days, C7 5 days)

8. Linear(automatic) alignment/1

9. Linear alignment/2 Fluctuations Drifts Internal power
Dark fringe power (W)
Fluctuations
100 sec
Drifts
1 hour

10. Linear alignment/3
Linear alignment completed: 10 degrees of freedom controlled with the full bandwitdh

11. Linear alignment/4
C6 (august 2005)
C5 (december 2005)
1 day

12. Interferometer internal power
Hierarchical control
Actuators noise
f < 10 mHz
Motivation: re-allocate the control force on upper stages to reduce actuator noise
Interferometer internal power
Force on marionetta
Force on mirror
10 mHz < f < 10 Hz
f > 10 Hz

13. Detector automation
Hundreds of operations during alignment/locking of ITF
 One single script to bring the detector in science mode in ~5 minutes
Automation status
Interferometer internal power
Marionette
Low noise coil drivers
AA ON
OMC lock
Other noise reductions and calibration
Lock to dark fringe with
variable finesse

14. C6 and C7 summary C6 (july 29th – aug 12th) C7 (Sept 14th sept 19th)
Partial automatic alignment
Science mode duty cycle 86%
Longest lock 40 hours
Best inspiral range 0.54 Mpc
Automatic science mode recovering ~5 minutes
C7 (Sept 14th sept 19th)
Full automatic alignment and full hierarchical control
Science mode duty cycle 65%
Longest lock 14 hours
Best inspiral range 1.65 Mpc
Automatic science mode recovering ~5 minutes

15. C6 and C7 Sensitivities
feedback noises
Shot noise

16. Next steps Change injection bench and increase the power (x10)
Commissisoning of “high power” interferometer
Restart the injection system
Restart the interferometer  January 2006
Check problems with high power (try to reach ~500 W on BS)
Complete ITF control set-up and tuning  February 2006
Start/Continue noise hunting
Priority first on middle-high frequency range (> 50 Hz)
Acoustic, diffused light, actuators noise…

17. Summary 90% of controls reliably working
Progress:
Automatic alignment completed
Full hierarchical control completed
First phase of automation completed
C6 and C7 data takings
1.65 Mpc
detector robust (C6: 86%, C7: 65%)
Detector left locked during nights, first trials
90% of controls reliably working
Science mode with a single script
Assembly of the new injection bench on going
Interferometer restart in January
Commissioning of high power interferometer
Noise hunting