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