1. Status of Virgo a short update Michele Punturo

2. A bit of History July 29 – August 13 2005 –C6 run Duty cycle: Locking 89%, Science Mode 86% September 14-19 2005 –C7 run Duty cycle: Locking 70%, Science Mode 65% 19 September 2005 –Shutdown of the interferometer and start of the ISYS upgrade

3. Upgrade motivations 1/2 Large frequency noise in the ITF –When the power recycling mirror is aligned large fringes are seen Cavity effect between the IMC and the PR Due to the large amount of light scattered in the IMC The insertion of a Faraday Isolator at the IMC output was needed to interrupt the light path from the ITF to the IMC Locking was impossible in this condition –Temporary solution adopted decreasing by a factor 10 the light injected in the IT »Increase of shot noise »Increase of electronic noise

4. Upgrade motivations 2/2 Structures at ~40, ~54, ~80 and 150 Hz More evident when the sensitivity improves Many of them were due to the modes of the IB Visible on the spectrum because of a mismatch between f mod and IMC length Excited by the control noise C6 C7 (beginning)

5. Upgrades Laser LB B2 Q2 1 Q2 2 RFC_DT IMC IMC_D1T Q1 2 Q1 1 B1p B5 B1s BS WI WE NINE PR RFCIB Q8 2 Q8 1 B7 Q8 1 Q8 2 B8 WB NB L=6m L=5.6m L=6.4m L=3km OMC OB EB

6. New IB

7. New PR Internal modes of the composite PR were affecting the locking of the ITF PR transfer function Standard Virgo size PR mirror installed

8. Others upgrade Other changes: –New Brewster window (IT/PR link) –New auto alignment system for the Input Mode Cleaner –Laser lab work –Update the layout of the benches –New injection tower flange –Cabling and electronic rack displacement –Laser electronic upgrade –Environmental Monitoring –Linear alignment hardware upgrade –New and low noise RF generator –DAQ upgrade –…

9. Current status The suspension in tower of the main components has been completed the 18th of November The ISYS towers have been closed the 19/12/2005 after a long integration activity (alignment, local control reactivation,…) –Vacuum Failure in a picomotor: tower opened again the 3/01/2006 Locking of the IMC on 00 mode the 05/01/2006 11/01/2006: –Starting of the IMC autoalignment Still failures in the picomotors Light start to be injected in the ITF

10. Noise budget in C7