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1 Virgo commissioning status M.Barsuglia LAL Orsay
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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)
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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
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4 Top stage Last stage Seismic filters Suspension system
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5 Detection system
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6 OMC locking Transmitted power signal TEM 00
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7 CITF sensitivity during e-runs Sept 2001 July 2002 Alignment control Frequency noise
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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
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9 July 2002 September 2003: Upgrade to Virgo mirrors installation arm completion, vacuum ITF upgrades (mode-cleaner, local controls, …) September 2003: Virgo commissioning
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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
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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
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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
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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)
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14 locking Locking at the first trial first lock ~ 1 hour frequency noise Transmitted power Frequency noise reduction
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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
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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
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17 Output mode-cleaner locking Transmitted P Reflected P 2 StateTemperatureError signal 2 min
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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)
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19 Shot noise Electronic noise (ADC) Frequency noise Control noise ? MC length control noise North cavity noise budget
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20 laser 50 Hz 300 kHz Ref Cav 50 Hz
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21 Transmitted P during C1 run tests Seismic Noise problem 3 days 14-17 november 2 Long locks
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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.
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23 Tidals during C1 run 50 m Correction sent to the end test mass
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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
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25 laser 50 Hz 300 kHz Ref Cav 50 Hz Frequency stabilization
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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
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27 laser 50 Hz 20 kHz. 300 kHz Ref Cav 1 Hz Frequency stabilization Last step: DC control of laser frequency
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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
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29 WFS control matrix optical matrix measured filter ready
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30 WSF control
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31 WFS control matrix optical matrix measured filter ready will be tested in early january transition from local controls WSF control
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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
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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
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34 Hierarchical control: 3 points
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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
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36 Hierarchical control: marionetta acquire the lock with the reference mass move the control to the marionetta DAC noise reduction complicated transfer function simulations
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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
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38 Recombined ITF B7 B1p B2B2 B8B8 north arm west arm B5B5 start noise analysis ~ 250 mW
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39 Lock acquisition B7 B1p B2B2 B8B8 B5B5 Step 1: lock north arm using pick-off 5 Done Step 2: lock west and mich
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40 Recombined ITF: simulation Trigger north satisfied north cavity locked Trigger west&mic satisfied west cavity lockedmic locked Acq_north ONAcq_west_mic ON
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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
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42 Lock acquisition LIGO method Time-Domain simulation (Siesta) Now transition 3 4 Lock acquisition for full ITF State 2 locked State 3 locked
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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
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