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Vibration measurements with and without Monalisa 15/07/09 Benoît BOLZON (LAPP) David Urner (Oxford) Paul Coe (Oxford) 1 Benoît BOLZON
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2. Comparison of Monalisa vertical vibrations on the wood prototype: - with no pressure - with pressure but no regulation - with pressure and regulation Goal: influence of regulation (too dangerous on real set-up) Outline 1. Relative motion calculation using representative absolute motion 3. Impact of Monalisa on vibrations (3 directions) between: - Shintake and QD0 with and without pressure - QD0 and QF1 with pressure Comparison of measurements with/without Monalisa Measurements without MONALISA have been repeated two weeks ago with cooling water flowing inside FD 4. Conclusion
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3 1. Calculation of relative motion using representative absolute motion measured at ATF2
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Choice of a representative ground motion measured at ATF2 Choice of a high ground motion during shift period Friday 12/12/08 at 3pm Above 0.2Hz: 218nm Above 1Hz: 128nm Amplitude almost the same during 4 hours of shift Choice of ground motion at 3pm representative 4 Relative motion calculation by taking this ground motion PSD gm H(k)= TF (SM/FD) PSD x (k)=TF (FD/floor) *PSD gm
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2. Comparison of Monalisa vibrations put on the wood prototype : - With no pressure - With pressure but no regulation - With pressure and regulation 5 Wood prototype only Wood prototype with Monalisa on it 3 MG102S accelerometers: On Shintake On QD0 On the floor
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Vibration transmission between Shintake and QD0 Coherence Transfer Function (TF) Magnitude Phase 6 No additional vibrations (TF magnitude) No change in phase (TF phase and coherence) With the regulation system:
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7 Relative motion of Shintake to QD0 No influence of pressure and regulation on relative motion If put on the real set-up which is really more rigid, results can not be different
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8 3. Impact of Monalisa on vibrations between: - Shintake and QD0 with and without pressure - QD0 and QF1 with pressure Comparison of measurements with/without Monalisa Vibration measurements between Shintake and QD0 Vibration measurements between QD0 and QF1
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9 Vibration transmission between Shintake and QD0 Vertical direction Almost same coherence: - With/without Monalisa - With/without pressure Only difference: QD0 resonance slightly lower due to Monalisa weight - No Monalisa: 65.3Hz - With Monalisa: 60.3Hz With Monalisa: Same transfer function with/without pressure
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10 Vibration transmission between Shintake and QD0 Vertical direction No pressure Transfer function measurements done during 4 hours the night (quiet) Frequency resolution: 0.016Hz Time resolution: 19 minutes Pressure Time Frequency Amplitude Frequency Amplitude Time Vibration measurements (with pressure in Monalisa) done simultaneously with frange measurements of SM Same transfer function (with and without pressure) over time
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11 Vibration transmission between Shintake and QD0 Vertical direction Below 4Hz: increase of relative motion due to not enough high SNR (coherence very close to 1: relative motion should not increase) Relative motion above 4Hz (should be the same than above 0.1Hz) : Relative motion above 4Hz: - No Monalisa: 5.0nm - Monalisa with pressure: 5.7nm - Monalisa without pressure: 5.8nm Almost no change compared to tolerances
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12 Vibration transmission between Shintake and QD0 Direction parallel to the beam Almost same coherence: - With/without Monalisa - With/without pressure Only difference: QD0 resonance slightly lower due to Monalisa weight - No Monalisa: 18.0Hz - With Monalisa: 16.6Hz With Monalisa: Same transfer function with/without pressure
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13 Vibration transmission between Shintake and QD0 Direction parallel to the beam Same relative motion with/without Monalisa (even better with Monalisa above 7Hz) Same relative motion with/without pressure in Monalisa
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14 Vibration transmission between Shintake and QD0 Direction perpendicular to the beam Almost same coherence: - With/without Monalisa - With/without pressure QD0 resonance almost the same: - No Monalisa: 20.4Hz - With Monalisa: 19.2Hz With Monalisa: Same transfer function with/without pressure SM resonance higher with Monalisa (59.6Hz 55.0Hz): good!
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15 Vibration transmission between Shintake and QD0 Direction perpendicular to the beam Same relative motion with/without Monalisa (even better with Monalisa above 10Hz) Same relative motion with/without pressure in Monalisa
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16 Vibration transmission between QD0 and QF1 Vertical direction With Monalisa: QD0 and QF1 resonances slightly appear (factor 5) since QD0 resonant frequency is slightly lower (due to Monalisa weight) Without Monalisa: QD0/QF1 resonances almost do not appear (very thin peak) since: their frequencies are almost the same QD0/QF1 move in phase (very close to each other)
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17 Vibration transmission between QD0 and QF1 Vertical direction Relative motion increase of 2nm with Monalisa due to QD0/QF1 resonances (decrease of QD0 resonant frequency) : very low! Solution: put a mass on QF1 to decrease its resonant frequency down to QD0 resonant frequency
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18 Vibration transmission between QD0 and QF1 Direction parallel to the beam With Monalisa: QD0/QF1 resonances slightly appear (factors 5) since QD0 resonant frequency is slightly lower (due to Monalisa weight) Without Monalisa: QD0/QF1 resonances almost do not appear (factors 2/3) since: their frequencies are almost the same QD0/QF1 move in phase (very close to each other)
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19 Vibration transmission between QD0 and QF1 Direction parallel to the beam Relative motion increase of 15nm with Monalisa due to QD0/QF1 resonant frequencies Very low increase compared to tolerances (500nm)
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20 Vibration transmission between QD0 and QF1 Direction perpendicular to the beam With Monalisa: QD0/QF1 resonances slightly appear (factors 5 and 3) since QD0 resonant frequency is slightly lower (due to Monalisa weight) Without Monalisa: QD0/QF1 resonances almost do not appear (factor 2) since: their frequencies are almost the same QD0/QF1 move in phase (very close to each other)
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21 Vibration transmission between QD0 and QF1 Direction perpendicular to the beam Relative motion increase of 25nm with Monalisa due to QD0/QF1 resonant frequencies Very low increase compared to tolerances (500nm)
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22 4. Conclusion
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23 With GM/flowing cooling water, relative motion of SM to QD0: ToleranceWithout Monalisa With Monalisa (Press/No press) Vertical 7 nm5.0nm5.7nm/5.8nm Perpendicular to beam ~ 500 nm16.7nm Parallel to the beam ~ 10,000 nm17.2nm Tolerances still achieved with Monalisa (almost no influence) N.B: No influence of the regulation system With GM/flowing cooling water, relative motion of QF1 to QD0: Without Monalisa With Monalisa and pressure Vertical 5.0nm7.0nm Perpendicular to the beam 8.9nm34.2nm Parallel to beam 10.9nm26.2nm In vertical direction: almost no influence of Monalisa In horizontal directions: still acceptable because of the large tolerances A solution: put a mass on QF1 to get same resonances than QD0 ones This is not an issue!!
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24 Analysis of transient vertical vibrations during pumping with Monalisa put on wood prototype ANNEXES
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25 Transfer function between Shintake and QD0 Vertical vibrations stationary during pumping when Monalisa put on the wood If put on the real set-up which is really more rigid, results can not be different (or can be even better) Frequency resolution: 2Hz Time resolution: 1s
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