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40 m Laboratory Upgrade Progress Report LSC meeting at LIGO Livingston observatory

40 m Laboratory Upgrade Progress Report LSC meeting at LIGO Livingston observatory Osamu Miyakawa, Caltech LIGO-G040081-00-R 40m Team : A. Weinstein, S. Kawamura, M. Smith, S. Vass, B. Taylor, J. Heefner, B. Abbott, L. Goggin, F. Kawazoe, S. Sakata, and R. Ward. Objectives.

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40 m Laboratory Upgrade Progress Report LSC meeting at LIGO Livingston observatory

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  1. 40m Laboratory Upgrade Progress Report LSC meeting at LIGO Livingston observatory Osamu Miyakawa, Caltech LIGO-G040081-00-R 40m Team: A. Weinstein, S. Kawamura, M. Smith, S. Vass, B. Taylor, J. Heefner, B. Abbott, L. Goggin, F. Kawazoe, S. Sakata, and R. Ward 40m Progress, LSC meeting, Mar. 2004

  2. Objectives • Develop lock acquisition procedure of detuned Resonant Sideband Extraction (RSE), • Characterize noise mechanism, • Verify optical spring effect, • Develop DC readout scheme, • etc. for Advanced LIGO, LCGT, and other future GW detectors 40m Progress, LSC meeting, Mar. 2004

  3. Target Sensitivity ofAdvanced LIGO and 40m 40m Progress, LSC meeting, Mar. 2004

  4. ETMy ITMy PSL ETMx ITMx BS MC Important Achievement (1)Installation of FP Michelson September, 2003 • Four TMs and BS: installed 40m Progress, LSC meeting, Mar. 2004

  5. ~ Important Achievement (2)Lock Acquisition of FP Michelson November 2003 • FP Michelson locked • Arms locked independently, and switched to common/differential servo • Digitally controlled suspensions • Finesse ~ 1200 • Seismic motion ~ 10 - 100 times noisier than LIGO site • UGF ~ 300Hz (limited by A/D and D/A speed) ETMY ITMY POY I ITMX ETMX Laser BS PC SP POX AP RF I Q Q I 40m Progress, LSC meeting, Mar. 2004

  6. Important Achievement (3)Spectrum of FP Michelson November ~ December 2003 • Displacement spectrum obtained • With all the whitening/de-whitening filters (2 of 4 orders) ON • No feedback to laser frequency • 2 months noise hunting • Noise is limited by electronic noise of de-whitening filter and frequency noise. De-whitening filter Frequency noise 40m Progress, LSC meeting, Mar. 2004

  7. ETMy ITMy PSL ETMx PRM ITMx BS MC SEM Important Achievement (4)Installation of PRM and SRM BS SRM February 2004 • Power Recycling Mirror (PRM) , Signal Recycling Mirror (SRM) installed • FPMI re-locked after installation PRM Bright port Dark port X arm Y arm 40m Progress, LSC meeting, Mar. 2004

  8. Other Achievements • Simple and reliable calibration for PSL frequency noise • Mode matching • ~ 1% tolerance • Estimation of loss on mirror • ~ 90ppm (design 35ppm) • Optical lever • Helped the installation of PRM and SRM • Input matrix of suspension • Third Pockel’s-cell for 166MHz modulation • Two peak photo detector (133MHz, 199MHz) for double demodulation • Replacement of NPRO and re-alignment of power amplifier • Total power ~12.5W 40m Progress, LSC meeting, Mar. 2004

  9. Signal Extraction Matrix ETMy L=(Lx Ly)/2 L=Lx Ly l=(lx ly)/2 l=lx ly ls=( lsx lsy)/2 Ly • Calculated by FINESSE (A. Freise: http://www.rzg.mpg.de/~adf/) • PO: light from BS to ITMy ITMy lsy ETMx PRM Laser ly ITMx BS lx Lx lsx SEM PO SP AP 40m Progress, LSC meeting, Mar. 2004

  10. Length Tolerances • Acceptable cavity length deviations from the ideal points: 6 cm for l 3 mm for l 3 mm for ls • Direct length measurement for PRC and SRC Error of the cavity length PR and SR ~ +/-1mm Example: Signal matrix with l deviation of 1 cm S. Kawamura, “Signal Extraction Matrix of the 40m Detuned RSE Prototype”, LIGO-T040010-00-R (2004) 40m Progress, LSC meeting, Mar. 2004

  11. Double Demodulation • Double Demodulation used for l+, l-, and ls • Demodulation phases optimized to suppress DC and to maximize desired signal [S.Kawamura, “Signal Extraction Matrix of the 40m Detuned RSE Prototype”, LIGO-T040010-00-R (2004)] 40m Progress, LSC meeting, Mar. 2004

  12. ETMy 1. lock central part using beat signal between f1 and f2 2. lock arm cavities ITMy ETMx PRM ITMx BS SEM Lock Acquisition of Detuned RSE • Central part: not disturbed by lock status change of arm cavity • Question: Not disturbed by flash of SBs or SBs of SBs in arms? • Promising: TAMA using 3rd harmonic demodulation in PRFPMI 40m Progress, LSC meeting, Mar. 2004

  13. Lock Acquisition of Central Part Ideal Procedure:Lock one by one [for example] Step 1: Lock l+ robustly Step 2: Lock l- robustly Step 3: Lock ls • Find primary signal not disturbed by the other two DOFs • Find secondary signal not disturbed by the residual DOF ITMy PRM ITMx BS Step 1 Step 2 Step 3 SEM 40m Progress, LSC meeting, Mar. 2004

  14. Quality of l+ Signal (dc=0, l+:Max) Error sig. 40m Progress, LSC meeting, Mar. 2004

  15. l+@SP, no offset • Signals for f1 resonance appear 40m Progress, LSC meeting, Mar. 2004

  16. Dependence of l+ Signal on Demodulation Phases 88 Error sig. Error sig. 40m Progress, LSC meeting, Mar. 2004

  17. Quality of l+ Signal (Symmetric, dc0) 88 Error sig. 40m Progress, LSC meeting, Mar. 2004

  18. l+@SP, Symmetric • Four SBs resonate at different points • Good signal obtained when +f2 resonates • Signal for –f2 resonance has an opposite polarity • Disturbed when +f2 and –f2 resonate at the same point • Signals for f1 resonance can be cancelled by proper DDM phases, which coincide with the phases for symmetric signal 40m Progress, LSC meeting, Mar. 2004

  19. l+ Signal lockable surface • l+ lock points makes one surface • Gain change<3 40m Progress, LSC meeting, Mar. 2004

  20. l+ Signal lockable surface • Lock point surface covers pretty much (~80%) of all the l-, ls parameters • Feedback l+ signal to laser frequency for fast locking (Feed around) 40m Progress, LSC meeting, Mar. 2004

  21. Quality of l- Signal Error sig. 40m Progress, LSC meeting, Mar. 2004

  22. Dependence of l- Signal on ls • No good signal obtained except for ls around resonant 40m Progress, LSC meeting, Mar. 2004

  23. l- Signal Divided byAP signal with different Dem. Phase Hint: H. Grote at GEO Divided by Error sig. Error sig. 40m Progress, LSC meeting, Mar. 2004

  24. Dependence of Dividedl- Signal on ls 40m Progress, LSC meeting, Mar. 2004

  25. Dependence of Dividedl- Signal on l+ 40m Progress, LSC meeting, Mar. 2004

  26. Quality of ls Signal Error sig. 40m Progress, LSC meeting, Mar. 2004

  27. Dependence of ls Signal on l+ • No good signal obtained except for l+ around resonant 40m Progress, LSC meeting, Mar. 2004

  28. Looking for Good Signal … Have tried many things, but not significant improvement… • f1-dem, f2-dem • Dither • For l+: Single sideband f2, AM f2 NR pm, am, single sideband f3: (f2-f3)-dem, (f1+f3)-dem On the surface of l+ • For l-, ls: Signal divided by the following: 2f1-dem, 2f2-dem, DDM with different dem phases, (f2-2f1)-dem On the surface of l+ 40m Progress, LSC meeting, Mar. 2004

  29. Summary • Lots of achievements; experiment on 40m going very fast and smoothly • Almost ready to try lock acquisition • Lock acquisition: not so easy • Need more investigation for lock acquisition Hope we succeed in locking detuned RSE very soon! 40m Progress, LSC meeting, Mar. 2004

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