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40m Laboratory Upgrade to prototype Advanced LIGO optics and controls

40m Laboratory Upgrade to prototype Advanced LIGO optics and controls. MILESTONES: 4Q 2001: Infrastructure complete PSL, 12m MC envelope, vacuum controls, DAQS, PEM. Conceptual design review. Begin procurement of CDS, ISC, etc. 2Q 2002:

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40m Laboratory Upgrade to prototype Advanced LIGO optics and controls

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  1. 40m Laboratory Upgrade to prototype Advanced LIGO optics and controls MILESTONES: • 4Q 2001: Infrastructure complete • PSL, 12m MC envelope, vacuum controls, DAQS, PEM. • Conceptual design review. Begin procurement of CDS, ISC, etc. • 2Q 2002: • All in-vacuum cables, feedthroughs, viewports, seismic stacks installed. • 12m input MC optics and suspensions, and suspension controllers. • 3Q 2002: • Begin commissioning of 12m input mode cleaner. • Acquisition of most of CDS, ISC, LSC, ASC. • 4Q 2002: • Core optics (early) and suspensions ready. Ten Suspension controllers. Some ISC. • Glasgow 10m experiment informs 40m program • Control system finalized • 2Q 2003: • Core optics (late) and suspensions ready. • auxiliary optics, IFO sensing and control systems assembled. • 3Q 2003: Core subsystems commissioned, begin experiments • Lock acquisition with all 5 length dof's, 2x6 angular dof's • measure transfer functions, noise • Inform CDS of required modifications • 3Q 2004: Next round of experiments. • DC readout. Multiple pendulum suspensions? • Final report to LIGO Lab. Primary objective: full engineering prototype of optics control scheme for a dual recycling suspended mass IFO, looking as close as possible to the Advanced LIGO optical configuration and control system • Key features: • Initial-LIGO Pre-stabilized laser • Initial-LIGO Input mode cleaner • Initial-LIGO suspensions • Power- and Signal-recycled Michelson • High finesse Fabry-Perot arms • Detuned signal cavity • Frontal modulation for control of all length & angular degrees of freedom • Output mode cleaner • DC readout of GW signal 40m status, 8/21/02

  2. 40m Laboratory Upgrade - Objectives Primary objective: full engineering prototype of optics control scheme for a dual recycling suspended mass IFO, Looking as close as possible to the Advanced LIGO optical configuration and control system • Key features: • Initial-LIGO Pre-stabilized laser • Initial-LIGO Input mode cleaner • Initial-LIGO suspensions • Power- and Signal-recycled Michelson • High finesse Fabry-Perot arms • Detuned signal cavity • Frontal modulation for control of all length & angular degrees of freedom • Output mode cleaner • DC readout of GW signal 40m status, 8/21/02

  3. Advanced LIGO technical innovations tested at 40m • a seventh mirror for signal recycling • (length control goes from 4x4 to 5x5 MIMO) • detuned signal cavity (carrier off resonance) • pair of phase-modulated RF sidebands • frequencies made as low and as high as is practically possible • unbalanced: only one sideband in a pair is used • double demodulation to produce error signals • short output mode cleaner • filter out all RF sidebands and higher-order transverse modes • offset-locked arms • controlled amount of arm-filtered carrier light exits asym port of BS • DC readout of the gravitational wave signal Much effort to ensure high fidelity between 40m and Adv.LIGO! 40m status, 8/21/02

  4. Differences between AdvLIGO and 40m prototype • Initially, LIGO-I single pendulum suspensions will be used • Full-scale AdvLIGO multiple pendulums will not fit in vacuum chambers • to be tested at LASTI • Scaled-down versions can fit, to test controls hierarchy – in 2004? • Only commercial active seismic isolation • STACIS isolators already in use on all 4 test chambers • providing ~30 dB of isolation in 1-100 Hz range • No room for anything like full AdvLIGO design – to be tested at LASTI • LIGO-I 10-watt laser, negligible thermal effects • Other facilities will test high-power laser: LASTI, Gingin, … • Thermal compensation also tested elsewhere • Small (5 mm) beam spot at TM’s; stable arm cavities • AdvLIGO will have 6 cm beam spots, using less stable cavities • 40m can move to less stable arm cavities if deemed useful • Arm cavity finesse at 40m chosen to be = to AdvLIGO • Storage time is x100 shorter • significant differences in lock acquisition dynamics, in predictable ways • Due to shorter PRC length, control RF sidebands are 36/180 MHz instead of 9/180 MHz; less contrast between PRC and SRC signals 40m status, 8/21/02

  5. Control topology for Advanced LIGO ETMperp Carrier RF Sidebands f1 RF Sidebands f2 ITMperp Input ITMinline ETMinline Symm Port PRM Pickoff SRM Asym Port 40m status, 8/21/02

  6. AdvLIGO and 40m noise curves 40m AdvLIGO (PF, 7/01) 40m status, 8/21/02

  7. Milestones achieved so far • Old IFO dismantled, surplus equipment distributed • Lab infrastructure substantially complete, incl new conditioned power, new 12” cable trays, new CDS racks • Vacuum control system complete (D. Ugolini) • Active seismic isolation system installed, commissioned (Vass, Jones, etc) • Vacuum envelope for 12m MC and output optic chamber installed (Vass, Jones) • All but one optical table in place (Vass, Jones) • Remaining on infrastructure: install seismic stacks for 12m MC and OOC; all in-vacuum cabling; and one more (big) optical table. • DAQ system installed, logs frames continuously (R. Bork) • PSL installed, commissioned; full tuning and characterization in progress (P. King, L. Cardenas, R. Karwoski, P. Russell, D. Ugolini, B. Abbott, SURFs) • Many PEM devices installed, in EPICS and DAQS, and in routine use (vacuum gauges, weather station, dust monitor, STACIS, accelerometer, mics, …) (Ugolini, SURF Tsai). 40m status, 8/21/02

  8. More milestones achieved • Full in-vacuum optical layout complete, incl. Mode matching and steering, optical levers, cameras (M. Smith) • Full out-of-vacuum IFO sensing table layout complete, for 11 output beams; parts lists assembled (M. Smith) • Scattered light control, baffling, isolators (M. Smith) • Design of digital suspension controllers for MC and COC in progress (B.Abbott, J.Heefner) • Computing hardware, networking, software (EPICS, Dataviewer, DMT, etc) largely in place (Bork, Ugolini, Bogue, Wallace) • Optical glass in hand, polishing of MC glass in progress (G. Billingsley) • Specs for polishing and coating core optics ready (G. Billingsley) • SOS suspensions (all but TM’s) constructed (J. Romie) • TM suspensions designed and in construction (J. Romie) • Detailed WBS for construction, and for experiment (T. Frey) 40m status, 8/21/02

  9. Conceptual Design Review • An internal Conceptual Design Review for the 40m Dual Recycling project was held on October 18, 2001. At that time, detailed conceptual designs were presented (with accompanying documentation) for the overall project, the tentative optical configuration and control scheme, the optical layout, all sensing table instrumentation, core suspended optics, mechanical suspensions, digital suspension controllers, and auxiliary optics (stray light control, initial alignment system, optical levers, video monitoring, etc), laboratory infrastructure and vacuum systems, environmental monitoring, data acquisition, computing and networking. Progress on key components was reviewed. The schedule of milestones (above) was again presented and discussed. The review committee was satisfied with the design and the progress, and a few specific concerns were addressed. 40m status, 8/21/02

  10. Milestones Achieved 1 • The laboratory building has been expanded and upgraded, providing room for electronics racks, optical tables, controls consoles, etc. • Power conditioners have been installed for all electronics. New cable trays have been installed. All electronics racks needed for the full interferometer controls have been installed. All optical tables and optical enclosures have been installed. A new control room, with display consoles, has been installed. • Vacuum equipment (pumps, gauges, RGAs) have been upgraded. An Initial-LIGO-like vacuum control system has been built and commissioned. The system is fully operational and in continual use. 40m status, 8/21/02

  11. Milestones Achieved 2 • The existing vacuum envelope has been augmented with a new output optic chamber with seismic stack, a 13 meter mode cleaner beam tube, a small chamber and seismic stack for the end mode cleaner suspended optic (MC2). New IR-coated optical ports, new flexible in-vacuum cables, new welded vacuum electrical feedthroughs, and new cameras and mounts for viewing the beam on the in-vacuum suspended optics have been installed. • In early 2001 a commercial active seismic pre-isolation system (STACIS) was installed on all four test mass chambers and is now in continuous use. • An Initial-LIGO pre-stabilized laser (PSL) was installed in spring 2001. It has been fully commissioned and characterized, and is in continual use. 40m status, 8/21/02

  12. Milestones Achieved 3 • An Initial-LIGO data acquisition system (DAQS) was installed in spring 2001, and has been in continual use. • EPICS slow control system, networking, and computer displays are all installed and in continual use. • A small number of environmental monitoring devices (dust counter, weather station, accelerometers, magnetometers) have been installed and are fully integrated into the EPICS slow control and DAQS systems. • The optics for the 13-meter mode cleaner were produced, polished, and coated. The polishing and coating quality was measured by LIGO optical engineers in March 2002. • The suspensions for the 13-meter mode cleaner were fabricated, cleaned and baked, and assembled, by March 2002. 40m status, 8/21/02

  13. Milestones Achieved 4 Mode Cleaner • During April 2002, the three suspended optics for the 13-meter mode cleaner were hung, tested, and installed into the vacuum envelope. • Digital suspension controllers for the mode cleaner suspensions were designed, fabricated, and finally installed into the laboratory by May 2002. The full digital suspension control system for all 10 suspended optics required for dual recycling will be in place by the end of FY02. • Mode cleaner length and frequency control servo electronics, and optical sensing trains and beam tubes, were installed into the laboratory by late May 2002. 40m status, 8/21/02

  14. Milestones Achieved 5 Mode Cleaner • The mode cleaner was aligned, and first fringes seen, in June 2002. As of August 14, the mode cleaner acquires lock robustly during the night (up to 8 hours observed) using SR560’s in place of MC Servo VCO path. • Lock acquisition is being tuned, and the characterization of the mode cleaner performance is in progress. SURF students are making major contributions to this effort. • The Global Diagnostics System (GDS), including DTT, AWG, and DMT have been installed, and DTT/AWG is in use. • PLOTS! Photos! 40m status, 8/21/02

  15. 13-meter Mode Cleaner lock M=3.0 earthquake at 3:10 AM ~8.7 hours 40m status, 8/21/02

  16. Milestones Achieved 6 Core suspended optics • The core optics for the main dual recycled interferometer were produced and polished, and coating of all pieces (including spares) is in progress as of July 2002. We expect completed pieces to be delivered and measured by LIGO optical engineers by the end of summer 2002. • The mechanical suspensions for the remaining 7 optics, for the main dual recycled interferometer, have been designed, fabricated, cleaned and baked. • We plan to assemble the suspensions, hang the remaining 7 optics, and install them into the vacuum envelope in the fall of 2002. 40m status, 8/21/02

  17. Next 9 months • Install alignment sensing and control on 13m mode cleaner. • Fully characterize 13m mode cleaner performance. • The digital suspension controllers for all 10 suspended optics should be complete by the end of calendar 2002. • Assemble, hang, and install the seven core suspended optics (PRM, SRM, BS, ITMx, ETMx, ITMy, ETMy) by the end of calendar 2002, and have them damped by the controller system. • Fabricate and install all remaining optical sensing equipment on the existing enclosed optical tables, by 2Q 2003. 40m status, 8/21/02

  18. Next 9 months • Fabricate and install auxiliary optics systems: scattered light control, initial alignment system, optical levers, video monitoring. • Fabricate and install the length sensing and control system. • Fabricate and install the alignment sensing and control system. • Data handling: fiber link to CACR? (Currently, we only save all trend frames, backed-up to AIT occasionally). • There may be some necessary augmentation of the DAQS, computing, networking, and environmental monitoring systems. 40m status, 8/21/02

  19. Longer term • The plan is to have all these systems installed, and the process of commissioning them begun, by summer 2003. First experiments in dual recycled configuration response, lock acquisition, and control are planned for summer 2003, and are expected to take at least a year. We expect that LSC members, as well as students, will participate in this most interesting phase of the project. • We will delay until FY04 the implementation of some elements of the project which have not yet been designed in any detail: the output mode cleaner, and the DC demodulation scheme. We also continue to consider the possibility of implementing multiple pendulum suspensions, again at a later stage in the project. 40m status, 8/21/02

  20. Alignment Sensing • SURF Marcus Benna has studied the WFS alignment signals for 40m and AdvLIGO. • He studied ModalModel, but could not succeed in making it work reliably for dual recycling. • He wrote his own, compact Mathematica calculation, comparing against Twiddle for DC fields, and Modal Model for Initial LIGO alignment sensing. • He finds that the sensing configuration (lengths, RF sidebands, pattern of resonances) which were designed for good length sensing, are NOT good for alignment sensing. • D(ETM) and D(ITM) signals are degenerate; the signals only appear in the dark port, and no signal is available in the bright port to break the degeneracy (as in Initial LIGO). • Reducing the sideband contrast (9/180 -> 36/180) may help; more f2 at bright port gives some D(ITM) signal there. • Still under investigation! 40m status, 8/21/02

  21. SURF 2002 • Surjeet Rajendran, Caltech • Analysis of coincident burst data • Marcus Benna, Cambridge University • Dual recycled AdvLIGO Alignment sensing • David Bonfield, Cambridge University • Mode Cleaner servo tuning and characterization • Ilya Berdnikov, Cornell University • Digital suspension controller characterization • Aya Sekido, Tokyo University • Mode matching and characterization of IOO 40m status, 8/21/02

  22. (Some) outstanding issues and action items (40m, AdvLIGO) • Any significant changes in people’s thinking re: optical configuration, controls, CDS architecture?? • IFO design (optics, sensing, control, etc) needs careful review by experts, double-check LSC, ASC calculations – I welcome volunteers!! • 180 MHz PD’s for WFS, LSC. Double demodulation(180  36 MHz). • Develop ASC model with ModalModel. • Design servo filters for LSC, ASC! • Detailed noise model (RSENOISE, Jim Mason) • Lock acquisition studies with E2E/DRLIGO. Develop lock acquisition algorithms, software. • Triple-check thermal effects (Melody) – negligible? • Output mode cleaner – will PSL-PMC-like device be adequate? (For 40m, for AdvLIGO). Suspended? • Offset-lock arms - algorithms, software. • DC GW PD – in vacuum? Suspended? 40m status, 8/21/02

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