1. 1 ILIAS Birmingham, 10/07/2008 H. Heitmann The Virgo+ shutdown

2. 2 ILIAS Birmingham, 10/07/2008 H. Heitmann Performances before V+ shutdown

3. 3 ILIAS Birmingham, 10/07/2008 H. Heitmann Virgo progress

4. 4 ILIAS Birmingham, 10/07/2008 H. Heitmann Virgo sensitivity: May 2008 Spikes: relaxation of magnet waterglass glueing

5. 5 ILIAS Birmingham, 10/07/2008 H. Heitmann Recent upgrades

6. 6 ILIAS Birmingham, 10/07/2008 H. Heitmann The cryotrap Brewster window (SR-DT) introduces noise Several attempts to mitigate scattered light Baffles in detection and SR towers, near the Brewster, … Final decision: remove it Avoid spoiling of central area vacuum from detection tower => cryotrap Cryotrap installation shutdown 10 days Interferometer locked immediately afterwards Nice success of the vacuum group Detection tower Signal recycling To ext. detection bench

7. 7 ILIAS Birmingham, 10/07/2008 H. Heitmann Cryotrap functioning Duration of functioning 3 days Refilling takes 1 hour Project of increasing functioning time to >= 1 week Before the next science run

8. 8 ILIAS Birmingham, 10/07/2008 H. Heitmann DAQ room air conditioning upgrade Air conditioning systems affects the Virgo sensitivity DAQ room is just in front of the detection lab the noise of its (oldest) air conditioning system has been found directly in the dark fringe AC ON AC OFF Central hall AC Water pump of CE CleanRooms AC  Laser lab DAQ room (+CE hall) North End AC

9. 9 ILIAS Birmingham, 10/07/2008 H. Heitmann DAQ room air conditioning upgrade Acoustic isolation of the DAQ => reduce noise in central area AC SR DT DT lab New AC system outside DAQ Microphone sees a noise reduction wrt. to the previous situation. before after AC off Hz

10. 10 ILIAS Birmingham, 10/07/2008 H. Heitmann Thermal compensation system Thermal lensing in the input mirrors has had a strong impact on commissioning Complicated locking procedure for surviving thermal transient Bistabilities arise during transition Be sure to catch the good state for continuing locking We want to go from 8 to 25 Watt in Virgo+ Much higher power => no hope to survive thermal deformations => Thermal compensation system needed CO2 laser ring system designed and realized by Roma Tor Vergata group with support by EGO

11. 11 ILIAS Birmingham, 10/07/2008 H. Heitmann TCS layout Electronics Chiller

12. 12 ILIAS Birmingham, 10/07/2008 H. Heitmann TCS optical layout

13. 13 ILIAS Birmingham, 10/07/2008 H. Heitmann TCS in-vacuum optics In vacuum steering mirrors needed

14. 14 ILIAS Birmingham, 10/07/2008 H. Heitmann TCS in-vacuum optics In vacuum steering mirrors needed

15. 15 ILIAS Birmingham, 10/07/2008 H. Heitmann TCS status CO2 laser problems One of the two lasers arrived broken from the company (Access Laser) Sent back but delivered again out of order Probably an undetected CO2 gas leakage Sent back to the company a second time WI TCS commissioning started Still many things to be learned, but: First encouraging results (see Enrico’s talk) To be done Power stabilization to be realized in the next months Central spot needed for reducing thermal transient time? Continue commissioning as soon as interferometer available again

16. 16 ILIAS Birmingham, 10/07/2008 H. Heitmann The Eddy current issue Increase of thermal noise due to Eddy current dissipation Too strong SmCb magnets + aluminum reference mass Noise level Virgo sensitivity: subject to discussions Magnetic noise coupling from external perturbations Solution 1 Ferromagnetic hats proposed for reducing magnetic field Solution 2 (chosen) In-place substitution of magnets with smaller ones Endoscopic procedure with tube, vacuum aspiration of dust etc. Worked well, except re-gluing of one FS support with “water glass” => glitches in WI? NE magnet substitution => No more Eddy current problems expected in Virgo+

17. 17 ILIAS Birmingham, 10/07/2008 H. Heitmann Upgrades during the Virgo+ shutdown

18. 18 ILIAS Birmingham, 10/07/2008 H. Heitmann Virgo+ shutdown Was scheduled for 3 rd of June May 9 th incident => shutdown anticipated by 3 weeks Required rearrangement of infrastructure works due to need of clean rooms Shutdown: Virgo+ packages High power laser + corresponding optics New control and DAQ electronics Environmental noise mitigation NE tower recovery

19. 19 ILIAS Birmingham, 10/07/2008 H. Heitmann Laser amplifier I Amplifies 20 W slave laser => 50 (up to 65) W Integration started 22/05 Old Virgo layout This part has been removed

20. 20 ILIAS Birmingham, 10/07/2008 H. Heitmann Laser amplifier II Much denser optical setup

21. 21 ILIAS Birmingham, 10/07/2008 H. Heitmann Pre Mode Cleaner PMC was designed for filtering of technical laser noise at 6 MHz Also guarantees a good beam shape

22. 22 ILIAS Birmingham, 10/07/2008 H. Heitmann mirror piezo Corundum ½ sphere Spider Zeroduractuator Brewster window Front mirrors Vacuum tank 0.35m - Triangular zerodur cavity * avoid thermal control - low mechanical Q - Controlled by 1 piezo * Corundum half sphere glued on piezo * Pushing a “telescope spider” shaped support * 6x12 diam. mirror, glued on spider -> Avoid piezo bending transfer to mirror displacement) ( simulation by F. Richard) - Vacuum tank, Brewster window 126mm 74mm Glued mirrors Mirror glued on piezo PMC mechanical scheme

23. 23 ILIAS Birmingham, 10/07/2008 H. Heitmann PMC on its cradle PMC tank PMC mounting

24. 24 ILIAS Birmingham, 10/07/2008 H. Heitmann External injection bench Super-polished optics for avoiding scattered light Polished by General Optics / coated by LMA, Lyon From laser To ITF

25. 25 ILIAS Birmingham, 10/07/2008 H. Heitmann Suspended injection bench Faraday isolation factor will go down with higher power (therm. lens) => insertion of remotely controllable waveplate for isolation improvement + compensation plate, if necessary

26. 26 ILIAS Birmingham, 10/07/2008 H. Heitmann Input mode cleaner mirror Old MC mirror was not good Too light (80x30 mm) radiation pressure forces reference mass suspension coil cables Bad optical quality; backscattering in opposite direction

27. 27 ILIAS Birmingham, 10/07/2008 H. Heitmann New MC payload New MC mirror payload Heavier (1.4 kg) Better optical quality

28. 28 ILIAS Birmingham, 10/07/2008 H. Heitmann Control and DAQ Electronics package Big change in electronics during shutdown Obsolete components Better design (differential ADC inputs,…), lower noise Better performance (global control speed, more filters,…) 1. DAQ electronics (LAPP, Annecy) Real time PCs, interconnected with Mux/Demux boards New ADCs, timing system Installation ongoing; to be finished during shutdown 2. New DSP for suspension control (Pisa) Much more powerful (6 DSP on one chip) Step-by-step installation, in parallel with old system Install new DAQ system check that new data is same as old one Install new global control system check that new Gc output is the same as old one Check compatibility of new system with suspension control (DSP) => when all tests positive, go to new system

29. 29 ILIAS Birmingham, 10/07/2008 H. Heitmann Suspension control STAC/Council June 200829 DAQ Room Computing Room Mode Cleaner Build. Mx/Dx RIO-B DSP Sc DSP Sa ADC PSD Platform RT PC NE/WE Terminal Building RIO-A Laser Lab Detection Lab Mx/Mx Mx/Dx IB DSP Sa DSP ScRIO-B ADC PSD RT PC RIO-A Mx/Dx PR/BS/NI/WI/ SR DSP Sa DSP ScRIO-B ADC PSD RT PC RIO-A Mx/Dx OB DSP Sa DSP ScRIO-B ADC PSD RT PC RIO-A Mx/Dx DSP SaDSP Sc RIO-B ADC PSD RT PC RIO-A Camera DACs ADCs Mx/Dx

30. 30 ILIAS Birmingham, 10/07/2008 H. Heitmann ISYS control STAC/Council June 200830 DAQ Room Computing Room Mode Cleaner Build. Mx/Dx RIO-B DSP Sc DSP Sa ADC Coil ADC PSD Platform RT PC NE/WE Terminal Building RIO-A Laser Lab ADC Env,Qt ADC SSFS,IMC ADC RFC,BMS RIO-A Lo:Vb:Qa Detection Lab RT PC CaRT RT PC ISYS RT PC DET Mx/Dx IB DSP Sa DSP ScRIO-B ADC PSD ADC Coil RT PC RIO-A PR/BS/NI/WI/ SR OB Camera RIO-A DSP Bc BMS DAC Camera DACs DAC ADCs

31. 31 ILIAS Birmingham, 10/07/2008 H. Heitmann ITF control STAC/Council June 200831 DAQ Room Computing Room Mode Cleaner Build. Mx/Dx RIO-B DSP Sc DSP Sa ADC Coil ADC PSD Platform RT PC NE/WE Terminal Building RIO-A Mx/Dx RIO-A Lo:Vb:Qa RIO-B B7Pos ADC B7ADC Q7 Laser Lab ADC Env,Qt ADC B2,B2_3f ADC SSFS,IMC ADC RFC,BMS RIO-A Lo:Vb:Qa Detection Lab ADC PiADC Mc ADC B1,B1pADC B1_2f,B1sADC B5,B5_2f RT PC CaRT RT PC ISYS RT PC tx,tyITFRT PC zITF RT PC DET Mx/Dx IB DSP Sa DSP ScRIO-B ADC PSD ADC Coil RT PC RIO-A Mx/Dx PR/BS/NI/WI/ SR DSP Sa DSP ScRIO-B ADC PSD ADC Coil RT PC RIO-A Mx/Dx OB DSP Sa DSP ScRIO-B ADC PSD ADC Coil RT PC RIO-A Mx/Dx DSP SaDSP Sc RIO-B ADC PSD ADC Coil RT PC RIO-A ADC Q5 ADC Q2 ADC Q1p Alignment RIO-A Calibration ADC Mx/Dx Camera RIO-A DSP Bc BMS DAC Camera DACs DAC 2 Cameras 2 DACs RIO-B1*,B5 Pos 4 Cameras RIO-A Lo:Vb:Qa 4 DACs RIO-A Lo:Vb:Qa 2 DACs ADCs ADC SFP,TCS ADC Ph.Cam

32. 32 ILIAS Birmingham, 10/07/2008 H. Heitmann Environmental noise reduction The reduction of the environmental noises is a “never ending story” During the shutdown a series of tests and actions is going on The major ones are the displacement of the laser lab electronics to a new “EE room” the displacement of the detection photodiodes under vacuum

33. 33 ILIAS Birmingham, 10/07/2008 H. Heitmann The EE (electronics equipment) room A part of the laser lab electronics racks will go to its own room Acoustically isolated Laser chiller has a separate room Laser lab EE room MC

34. 34 ILIAS Birmingham, 10/07/2008 H. Heitmann Photodiodes under vacuum 34 Photodiodes, the pre- amplifier, the motors and supports will go under two vacuum proof boxes, air filled (electronics cooling) Putting photodiodes under vacuum for reducing environmental noise coupling through scattered light

35. 35 ILIAS Birmingham, 10/07/2008 H. Heitmann The boxes Boxes are in steel (3mm thick) and their behavior in vacuum has been FEM studied at LAPP. The additional weight should be compliant with a minor retuning of the suspension

36. 36 ILIAS Birmingham, 10/07/2008 H. Heitmann Summary – upgrades already made Cryotrap installation For getting rid of “Radio Brewster” DAQ room airconditioning improvement For reducing environmental noise Thermal compensation system Installed, but laser broken; to be commissioned Magnet weakening Results to be seen after restart

37. 37 ILIAS Birmingham, 10/07/2008 H. Heitmann Summary - Virgo+ shutdown upgrades Injection system optics Laser amplifier – installed, long term observation going on Pre-Mode cleaner – installed, locked Low scattering optics on ext. bench - optics delivered Faraday isolation, remote tuning - to be installed Mode cleaner curved mirror with marionette+reference mass Installed: MC has been relocked Laser lab electronics equipment room Infrastructure works finished; electronics to be migrated Photodiodes under vacuum To be installed after whole ITF has been relocked again New DAQ electronics Ongoing; to be finished before relock New suspension electronics To be done in a second time

38. End

39. 39 ILIAS Birmingham, 10/07/2008 H. Heitmann Cryotrap: Residual gas analysis RGA installed on trap (SR side) Before (blue) and after (black) the DT opening, and compared to DT (blue) air H2H2 water Contamination 1E-10 mbar Part. pressure (mbar)