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aLIGO Photon Calibrators Calibration Pablo Daveloza University of Texas at Brownsville and

aLIGO Photon Calibrators Calibration Pablo Daveloza University of Texas at Brownsville and B. Abbott, J. Berliner, C. Conley, S. Shankle, T. Steckler, R. Savage. Overall Concept. Pcal Receiver. End Test Mass. Pcal Transmitter.

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aLIGO Photon Calibrators Calibration Pablo Daveloza University of Texas at Brownsville and

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  1. aLIGO Photon CalibratorsCalibration Pablo Daveloza University of Texas at Brownsville and B. Abbott, J. Berliner, C. Conley, S. Shankle, T. Steckler, R. Savage LVC Meeting - Rome, Sept. 10-14 2012

  2. Overall Concept Pcal Receiver End Test Mass Pcal Transmitter Power-modulated auxiliary lasers induce modulated displacement of End Test Masses. Two-beam configuration to minimize impact of elastic deformation of surface of optic. LVC Meeting - Rome, Sept. 10-14 2012

  3. Overall concept • aLIGO Photon calibrator (Pcal) • System capable of being the primary calibration method for aLIGO • Provide reference periodic test mass displacements via photon radiation pressure • Conceptually simple, one-step calibration method • Displacements on order of what is expected for gravitational waves • Relies on accurate measurement of modulated laser power - measurement standard calibrated at NIST • Reference displacements at 50, 400, 1100 Hz with a SNR of 20, and 2000 Hz with a SNR of 10 • one for each ETM LVC Meeting - Rome, Sept. 10-14 2012

  4. History • Used in Glasgow, GEO, Virgo, etc. • Glasgow 2001, ……. • Initiated for LIGO by Fritschel, Sigg, et al. more than 10 years ago • Developed by Goetz, Savage, et al. during iLIGO • Calibration of the LIGO displacement actuators via laser frequency modulation - Class. Quantum Grav. 27 (2010) 215001 (10pp) • Established confidence in accuracy of FSM calibration at the ±5% level • Accurate calibration of test mass displacement in the LIGO interferometer – Class. Quantum Grav. 27 (2010) 084024 (11pp) • Upgraded for eLIGO by West and Savage and operated continuously during S6 • Showed that long-term stability of voice coil actuation coefficients AND photon calibrators is better than ?? 0.1% - Sottile, Berliner, Savage … • – Characterization of the Photon Calibrator data from LIGO’s sixth Science Run • Baseline calibration method for aLIGO • Photon Calibrator subsystem (R. Savage lead) under the Auxiliary Optics subsystem (AOS) LVC Meeting - Rome, Sept. 10-14 2012

  5. Comparison betweendifferent calibration method LVC Meeting - Rome, Sept. 10-14 2012

  6. Pcal: 2 beams vs. 1 beam Single, centeredPcal beam Two-beam Pcal LVC Meeting - Rome, Sept. 10-14 2012

  7. Overview of method power modulated laser 2P cos(theta)/mc omega^2, etc. LVC Meeting - Rome, Sept. 10-14 2012

  8. Lessons learned local elastic deformation - Hild reference, iLIGO measurements, two-beam concept - plot from Goetz and Savage bulk elastic deformation - Mahmuda radius, modes, plots from Daveloza et al. aLIGO implications - plot from Amaldi talk, reference publication of talk LVC Meeting - Rome, Sept. 10-14 2012

  9. aLIGOCalibration Accuracy • aLIGO requirement: • “The amplitude of the sinusoidal radiation-induced displacements of the ETMs shall be accurate within 5% and 16 microseconds over 2 sigma confidence intervals.” • Pcal subsystem not responsible for calibration only accuracy of induced displacement • Science requirement: • “Lindblom” • requirements from other analysis groups • S5 result (calibration accuracy), Goetz and Savage Cal. compar plot • S6 result • error analysis from Pcal paper • importance of absolute power calibration LVC Meeting - Rome, Sept. 10-14 2012

  10. aLIGO Performance Requirements for laser(this could go in the second talk) relative power noise harmonic suppression timing LVC Meeting - Rome, Sept. 10-14 2012

  11. Absolute power calibration Transfer of Gold Standardto Working Standard In-chamber measurement of optical efficiency LVC Meeting - Rome, Sept. 10-14 2012

  12. Pcal timing synchronization LVC Meeting - Rome, Sept. 10-14 2012

  13. 2011 NSF Review Comment “AOS:• TCS and Pcal design completion should be given high priority to bring the Auxiliary Optical Systems in sync with the excellent progress being made on the other subsystems.” • Pcal Final Design Review completed January 2012 • I. Romero, mechanical designer at Caltech, worked full-time on Pcal mechanical designs. • In-vacuum beam paths, periscope support structure, pylon locations, etc. • In-vacuum hardware designs now being detailed by Scott Shankle at Caltech • Procurement underway – lasers, mirrors, breadboards, in-vacuum mounts, etc. LVC Meeting - Rome, Sept. 10-14 2012

  14. Functional Requirements 5% absolute length modulation accuracy, for modulation frequencies from 10 Hz to 2 kHz. Three simultaneous excitations with SNR > 20 with 1-second DFTs (~ 50 Hz, ~ 400 Hz, ~ 1 kHz) ~ 2 kHz excitation with SNR > 20 with 60-second DFTs. Swept-sine measurements of interferometer response from 10 Hz to 1 kHz with good SNR in less than 1 hour. Noise Requirements: Harmonic noise < 10% of aLIGO design sensitivity with 60-second DFTs RPN-induced displacement < 10% of aLIGO design sensitivity. LVC Meeting - Rome, Sept. 10-14 2012

  15. Absolute Power Calibration • Pcal internal power monitors calibrated by: • Gold Standard power sensor that is calibrated at NIST • Working Standard power sensors calibratedby Gold Standard • Integrating spheres with InGaAs photoreceivers • Developed in consultation with J. Hadler at NIST LVC Meeting - Rome, Sept. 10-14 2012

  16. Gold/Working Standard Calibration LVC Meeting - Rome, Sept. 10-14 2012

  17. Elastic Deformation of Test Mass Drumhead iLIGO Pcal spots Butterfly • Comsol finite element modeling(P. Daveloza) • Locate two beams at radial positions that minimize excitation of the drumhead mode • 111.6 mm for a 170.1 mm radius aLIGO ETM LVC Meeting - Rome, Sept. 10-14 2012

  18. Hardware Configuration LVC Meeting - Rome, Sept. 10-14 2012

  19. aLIGO Transmitter Layout • Based on eLIGO design • Symmetric design for Left/Right symmetries • Breadboard: 2” thick; off-the-shelf (TMC, e.g.) • Laser: CrystaLaser 2W Nd:YLF. • Detectors: B. Abbott design for eLIGO Pcal ISS. Need new package design for mounting to integrating spheres LVC Meeting - Rome, Sept. 10-14 2012

  20. Pcal Transmitter Pylon Openings in 19” rack format for mounting Pcal electronics AnSys FEA analysis complete (K. Holtz) Copy design of Opt. Lev. Pylons (R. DeSalvo, et al.) Drawings complete, submitted for internal review before procurement LVC Meeting - Rome, Sept. 10-14 2012

  21. Receiver Module • Breadboard: ½” thick alu.; off-the-shelf (ThorLabs) • 4” integrating sphere – same as Working Standard and Gold Standard • Room for periodic calibrations with Working Standard – 2” mirror on kinematic mount LVC Meeting - Rome, Sept. 10-14 2012

  22. Optical Lever Receiver Pylon RODA with Optical Levers LIGO-M1200020 for Receiver Plyon location - approved LVC Meeting - Rome, Sept. 10-14 2012

  23. H1, L1 Optical Paths Updated periscope assembly LVC Meeting - Rome, Sept. 10-14 2012

  24. Added ScopeETM Camera Periscopes Receive-side view Transmit-side view • Views partially blocked byArm Cavity Baffles • Locate steering mirrors as close to BT centerline as possible LVC Meeting - Rome, Sept. 10-14 2012

  25. Pcal Photodetectors • GAP2000 InGaAs photodiodes • 2 mm diameter in TO-5 case • AD 829 Op. amp for transimpedance amplifier • Use existing eLIGO PSL ISS PDs for OFS sensor • 6 plus spares required • 3” -> 4” optical height spacers exist • Re-package for mounting to integrating spheres for power sensors • New circuit board and housing • 15 plus spares required eLIGO ISS PD LIGO-D030452 B. Abbott LVC Meeting - Rome, Sept. 10-14 2012

  26. Channel List/DAQ Configuration LVC Meeting - Rome, Sept. 10-14 2012

  27. References Accurate calibration of test mass displacement in the LIGO interferometers, E. Goetz et al., Class. Quant. Grav., Vol.27, pp. 084024-33, 2009. Precise calibration of LIGO test mass actuators using photon radiation pressure, E. Goetz et al., Class. Quant. Grav., Vol. 26, pp. 245011-23, 2009. Calibration of the LIGO displacement actuators via laser frequency modulation, E. Goetz and R. L. Savage, Jr., Class.Quant.Grav., Vol. 27, pp. 215001-10, 2010. Accurate measurement of the time delay in the response of the LIGO gravitational wave detectors, Y. Aso et al., Class. Quant. Grav., Vol. 26, pp. 055010-22, 2009. Calibration of the LIGO Gravitational Wave Detectors in the Fifth Science Run, J. Abadie et al., Nucl.Instrum.Meth., Vol. A624, pp. 223-240, 2010. Optimal calibration accuracy for gravitational-wave detectors, L. Lindblom, Phys. Rev. D 80, 042005, pp. 1-7, 2009. LVC Meeting - Rome, Sept. 10-14 2012

  28. LIGO-India ImplicationsAOS Photon Calibration • Reduced scope: No installation-phase testing of H2 equipment • New scope: none • Procurement decision: Do we buy the lasers for India now, or wait five years? • Non-Project activities: • determining best approach for storage and shipping of equipment • design/fabrication of storage/shipping containers • Moving and storing hardware • Procurement of additional operational spare laser and other components such as AOMs, electronics, etc. for India • What is sent: All H2 equipment • Not sent: in-air cabling LVC Meeting - Rome, Sept. 10-14 2012

  29. Cost Breakdown Baseline budget $1,128 k without ETM Camera Periscopes LVC Meeting - Rome, Sept. 10-14 2012

  30. AOS Pcal Schedule Highlights • Final design completed Feb. 15, 2012 • Hardware procurement underway • Pylons out for quotes • Lasers ordered • Breadboards, mirrors, mirror mounts – 50% ordered or quoted. • Periscope support structures – drawing detailing in progress. • Electronics – discussions with R. Abbott regarding procurement LVC Meeting - Rome, Sept. 10-14 2012

  31. AOS Pcal Critical Path • Procurement of in-vacuum periscope assemblies behind schedule • Currently still detailing design drawings • Pre-alignment now planned at LHO, with clean ship to LLO • Current schedule has L1 X-arm installation set for Sept. 7, 2012. We are confident that we will be ready before this date. LVC Meeting - Rome, Sept. 10-14 2012

  32. AOS Pcal Tracking Milestones Production start delayed by completion of FDR. Expect to meet installation dates on official Current schedule. LVC Meeting - Rome, Sept. 10-14 2012

  33. AOS Pcal Performance and Variances • SV: Procurement of lasers (most expensive item) will be phased • First unit 4-6 weeks from Apr. 1. Order balance after few weeks evaluation. • CV: Insignificant (due to purchase of CDS racks, by others) • EAC: Based on FDR updated cost estimate • VAC: + $281k (design optimization, less expensive lasers, etc.) LVC Meeting - Rome, Sept. 10-14 2012

  34. AOS Pcal Contingency Adjustments • Don’t expect to require more money for hardware. • May require more time (money) for manpower. • Mechanical designer to complete in-vacuum hardware designs/procurement • Interfaces with SLC, OL, etc. • Electronics design and fabrication • Optical follower servo, photodetectors, interfaces, etc. • Concerns: • Availability of manpower in AOS labor pool for mechanical design, electronics design, fab and testing, and installation. LVC Meeting - Rome, Sept. 10-14 2012

  35. Summary of AOS Pcal Status • In procurement phase • Pylons, lasers, breadboards, optics, mounts, etc. • In drawing detailing phase (still) • In-vacuum periscope support structures • Transmitter and receiver enclosures, misc. small items • Expect to meet official Current schedule dates • Expect to keep hardware costs within updated (FDR) budget • May require additional manpower for mechanical design, and electronics design, fabrication, and testing LVC Meeting - Rome, Sept. 10-14 2012

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