Cascina, January 24, 2005 Status of GEO600 Status of GEO600 Joshua Smith for the GEO600 team
Jan 15, 2016
Cascina, January 24, 2005
Status of GEO600Status of GEO600
Joshua Smith for the GEO600 team
Joshua Smith, Cascina, January 24,
2005
Optical LayoutOptical Layout
Joshua Smith, Cascina, January 24,
2005
Since Last Meeting Sept-Jan 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
““GEO City”GEO City”
Workshop Central Building
Bathrooms
OfficesControl Room / Visitor Center
Joshua Smith, Cascina, January 24,
2005
Scattered LightScattered 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*
* talk by S. Hild
Joshua Smith, Cascina, January 24,
2005
Post-scattering Noise HuntingPost-scattering Noise Hunting
Dec 4-Dec 12–Noise projections, noise hunting reveal limiting noise sources
Detection + shot noise Dark port ampl. Noise
Projections to hQ(t) 04.12.04
Joshua Smith, Cascina, January 24,
2005
Increased Laser PowerIncreased Laser Power
Dec 16-20– 0.57 transmission filters in
front of all photo-diodes– Increase injected laser power
35 W into first Modecleaner
11.7 W into Power Recycling Cavity
270450 W at the Beamsplitter
3050 mW at the detector output
– ?% MI sideband
– ?% SR sideband
– ?% Carrier
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
Joshua Smith, Cascina, January 24,
2005
Dark Port Amplitude NoiseDark Port Amplitude Noise
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
Moving RF Amplifier
Joshua Smith, Cascina, January 24,
2005
Decreased MI Mod. DepthDecreased 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
Michelson Feedback NoiseMichelson 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
Crossing 10Crossing 10-21-21/rt(Hz)/rt(Hz)
Joshua Smith, Cascina, January 24,
2005
Decreased SR Mod. DepthDecreased 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
GEO Sensitivity HistoryGEO Sensitivity History
Joshua Smith, Cascina, January 24,
2005
Jan 14 `05 vs. 1kHz DesignJan 14 `05 vs. 1kHz Design
Joshua Smith, Cascina, January 24,
2005
GEO Summary ReportsGEO 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
Overnight & Weekend RunsOvernight & Weekend RunsConsist of 1500 Hours total, during which >93% Duty CycleConsist of 1500 Hours total, during which >93% Duty Cycle
Inspiral Range History
Joshua Smith, Cascina, January 24,
2005
Noise Projection AutomationNoise 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
Noise Projections Noise Projections Vetoes Vetoes
Joshua Smith, Cascina, January 24,
2005
Future PlansFuture Plans
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
Joshua Smith, Cascina, January 24,
2005
Injected Sideband PowerInjected Sideband Power
0.08 0.085 0.09 0.095 0.1 0.105 0.11 0.115 0.12 0.1250.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
0.22reflected light from MPR, DRMI unlocked
carrier peak 3.24V
Normalized:
C = 1
MI = .035 .017
SR = .044 .015
PR = .006