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Status of GEO600

Status of GEO600. Joshua Smith for the GEO600 team. Optical Layout. Since Last Meeting Sept-Jan. Sensitivity improvement Better grasp of noise sources Maturing detector characterization and noise analysis programs Transition to observatory operation Mehr platz…. “GEO City”. Workshop.

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Status of GEO600

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  1. Status of GEO600 Joshua Smith for the GEO600 team Cascina, January 24, 2005

  2. Optical Layout Joshua Smith, Cascina, January 24, 2005

  3. Since Last Meeting Sept-Jan • Sensitivity improvement • Better grasp of noise sources • Maturing detector characterization and noise analysis programs • Transition to observatory operation • Mehr platz… Joshua Smith, Cascina, January 24, 2005

  4. “GEO City” Workshop Central Building Offices Control Room / Visitor Center Bathrooms Joshua Smith, Cascina, January 24, 2005

  5. Scattered Light • Sept 27-Nov16 • Various experiments to identify excess noise • Mirror misalignment, different DC alignments • Tapping of optics, bellows, tubes • Acoustically “quiet run” • Bellow damping • Output beam through spatial filters and optical fiber • Output optics in vacuum • Filter experiments* • Nov 17-Nov 29 • Reducing scattering* Joshua Smith, Cascina, January 24, 2005 * talk by S. Hild

  6. Projections to hQ(t) 04.12.04 Post-scattering Noise Hunting • Dec 4-Dec 12 • Noise projections, noise hunting reveal limiting noise sources • Detection + shot noise • Dark port ampl. Noise Joshua Smith, Cascina, January 24, 2005

  7. Increased Laser Power Naïve Picture: 2 Power(carrier) = sqrt(2) Amp(carrier & MISB) Signal = Amp(carrier)*amp(MIsb) = 2 Power on HPD = 2 Shot = sqrt(2) Dark = 1 Win sqrt(2) with shot Win 2 with dark noise • Dec 16-20 • 0.57 transmission filters in front of all photo-diodes • Increase injected laser power • 35 W into first Modecleaner • 11.7 W into Power Recycling Cavity • 270450 W at the Beamsplitter • 3050 mW at the detector output • ?% MI sideband • ?% SR sideband • ?% Carrier Joshua Smith, Cascina, January 24, 2005

  8. Dark Port Amplitude Noise Moving RF Amplifier • Dec 23-Jan 17 • Dominant noise coupled via MI modulation path • Decreased modulation depth 2x • Amplitude stabilized 15MHz FMI • Better gain distribution, cabling reduced pickup on 10m sending path P Q Joshua Smith, Cascina, January 24, 2005

  9. Decreased MI Mod. Depth • Dec 29 • Factor 2 Naïve Picture: 0.5 Power(MISB) = 0.7 Amp(MISB) Signal = Amp(carrier)*Amp(MISB) = 0.7 Power on output diode = 0.5 (Mostly MISB ) Shot = 0.7 Dark = 1 Pickup = 1 Ideas: - Nonlinear dependence of EOM or RF amplifier noise on signal size? Joshua Smith, Cascina, January 24, 2005

  10. Michelson Feedback Noise • Jan 5-8 • Problems addressed: • Square-root circuit • ESD Bias voltage • Gain distribution • Pickup • Slight improvement around 100 Hz • Problems remaining: • Further reduction of bias to reach design sensitivity • Will increase bilinear upconversion and beats Joshua Smith, Cascina, January 24, 2005

  11. Crossing 10-21/rt(Hz) Joshua Smith, Cascina, January 24, 2005

  12. Decreased SR Mod. Depth • Jan 19 • Factor 3 • SR control loop noise not limiting • FSR AM coupling to the carrier or FMI due to the “noisy” removal of light at the Signal Recycling EOM? Joshua Smith, Cascina, January 24, 2005

  13. GEO Sensitivity History Joshua Smith, Cascina, January 24, 2005

  14. Jan 14 `05 vs. 1kHz Design Joshua Smith, Cascina, January 24, 2005

  15. GEO Summary Reports Lock List Duty Cycle Sensitivity Calibration Stationarity Glitches Lines Data Quality www.geo600.uni-hannover.de/georeports/ Joshua Smith, Cascina, January 24, 2005

  16. Overnight & Weekend Runs Consist of 1500 Hours total, during which >93% Duty Cycle Inspiral Range History Joshua Smith, Cascina, January 24, 2005

  17. Noise Projection Automation • Semi-automatic Projections • Measure “snapshot” transfer functions • Measure noise FFTs live and simultaneously • TF amplitude and phase checks at noise calibration lines • During measurement • Long-term Joshua Smith, Cascina, January 24, 2005

  18. Noise Projections  Vetoes Joshua Smith, Cascina, January 24, 2005

  19. Near term Install crystal oscillators Oscillator amplitude + phase noise Increase to full laser power Shot noise + detection noise Hardware freeze mid Feb. Monitors, alarms Channel quality Noise projections Join LSC S4 Medium term Install final PR mirror Reach design sensitivity Future Plans Joshua Smith, Cascina, January 24, 2005

  20. Injected Sideband Power Normalized: C = 1 MI = .035  .017 SR = .044  .015 PR = .006 Joshua Smith, Cascina, January 24, 2005

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