Status of GEO600
Benno Willkefor the GEO600 team
ESF Exploratory Workshop
Perugia, September 2005
ESF 05 / GEO, B. Willke
ESF 05 / GEO, B. Willke
container cluster 2005
Workshop Central Building
Bathrooms
OfficesControl Room / Visitor Center
ESF 05 / GEO, B. Willke
Tube / Trench
ESF 05 / GEO, B. Willke
Clean Room / Control Room
ESF 05 / GEO, B. Willke
Triple Pendulum Suspension
ESF 05 / GEO, B. Willke
Thermal Noise / Monolithic Suspension
Silicate (Hydroxy- Catalysis) Bonding
Weld
ESF 05 / GEO, B. Willke
reaction pendulum
ESF 05 / GEO, B. Willke
12W Laser
modecleaner
interferometer with „dual recycling“
detektor
GEO 600 – optical layout
ESF 05 / GEO, B. Willke
Dual Recycling Length Control
ESF 05 / GEO, B. Willke
< 10 Hz
> 10 Hz
< 0.1Hz
Michelson length control
Reaction Pendulum:
3 coil-magnet actuators at intermediate mass, range ~ 100µm
Electrostatic actuation on test mass bias 630V, range 0-900V= 3.5µm
ESF 05 / GEO, B. Willke
Alignment Control
Alignment Control
differential wave-front sensing
spot position control
4 degrees of freedom at MC 1
+4 at MC 2+4 at MI (common mode)+2 at MI (differential mode)+2 at Signal-Recycling cavity
16 + 20 = 36
ESF 05 / GEO, B. Willke
GEO 600 design sensitivity
ESF 05 / GEO, B. Willke
102
103
10-21
10-20
10-19
10-18
10-17
Frequency [Hz]
h(t
) [H
z-1/2
]
Jan 02
Aug 02 (S1)
Jan 04 (S3)
Sept 05
Feb 05 (S4)
Aug 04
Evolution of the GEO 600 Sensitivity
ESF 05 / GEO, B. Willke
GEO600 Duty Cycle
date run name duty cycle
longest lock
Jan 2002 E7 75% 3h 40min
Aug 2002 S1 98% 121h
Nov 2003Jan 2004
S3-I (7days)S3-II(14 days)
95%98%
95h
Aug 2004 –Jan 2005
over night runs
(51 days)
94%
Mar 2005 S4 97% 52h
ESF 05 / GEO, B. Willke
S4
Feb 22nd – March 23rd, 708 hours Two manned shifts/day (5-21 UTC), 1 „Expert-On-Duty“ 8-8UTC Fully automated overnight shifts; SMS alarms to ‚E-O-D‘
Locking status DAQS (DCUs running, frame making, timing, calibration) Temperatures Vacuum
Instrumental duty cycle 97.5%, 95% w/o noisy period, 72%>10h
Longest lock 52h
ESF 05 / GEO, B. Willke
detector characterization
Sensitivity Min/max spectrum of
h(t) 15 BLRMS of h(t) Inspiral monitor Spectrogram of h(t)
Calibration Data quality Chi2 Calibration
parameters
Bursts (HACRmon) Time frequency
distribution SNR distribution Duration Bandwidth
Lines (Linemon) Line cataloguing Harmonic
identification Sideband
identification
ESF 05 / GEO, B. Willke
Typical S4 Sensitivity
ESF 05 / GEO, B. Willke
Calibration
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On-line optical TF measurements
actuator optical
CAL P and Q
h
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Calibration
radiation pressure
calibrator
?
ESF 05 / GEO, B. Willke
Photon Pressure Calibrator
Good agreement with ESD calibrationWavelength: 1035 nm @ 20°CMax. power: 1.4 W, FWHM= 0.66nm
ESF 05 / GEO, B. Willke
Optical Gain
ESF 05 / GEO, B. Willke
Calibrated EP Quadrature Signals
h [1
/sqr
t(H
z)]
ESF 05 / GEO, B. Willke
Combining hP(t) and hQ(t) – results
h [1/sqrt(Hz)]
Get the best of hP and hQ plus a little extra!
Get the best of hP and hQ plus a little extra!
ESF 05 / GEO, B. Willke
Laser
Michelson Interferometer
Output Mode Cleaner
Mode Cleaners
10W 1.6W
1500W (typ.) 2000W (max) atBeam Splitter
5W
~40mW
T=0.09%
Power Recycling Cavity:
Mode matching >85%Finesse 8300Linewidth 30 Hz
4/0.09%*1.6 = 7000
increase of power recycling factor
ESF 05 / GEO, B. Willke
Thermal lensing in BSoutput mode pattern (PRMI)
Directly after relocking
f=20km
A few minutes after relocking
f= 8km
→ α≈0.3 +/- 0.05ppm/cm
ESF 05 / GEO, B. Willke
GEO 600 design sensitivity
ESF 05 / GEO, B. Willke
Tuning signal recycling to 300 Hz
lock acquisition at 5kHz
tuning needs to adjust of 6 parameters (look-up table)
improved input file for simulations and how to transfer results to experiment
achieved downtuning to 200Hz
MI AA instability could be fixed
ESF 05 / GEO, B. Willke
Interferometer Readout - Sidebands
phasemodualtor
laser beam splitter
mirror
mirror
photodetector
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Schnupp – Modulation
phasemodualtor
laser beam splitter
mirror
mirror
photodetector
ESF 05 / GEO, B. Willke
Gravitational Wave Side Bands
phasemodualtor
laser beam splitter
mirror
mirror
photodetector
ESF 05 / GEO, B. Willke
Detuned Signal Recycling
phasemodualtor
laser beam splitter
mirror
mirror
photodetector
ESF 05 / GEO, B. Willke
Unbalanced Sidebands
PRC
SRCbroad-band
SRCdetuned to1.1 kHz
MI-sidebandsSR-sidebands broadband
SR-sidebands1.1kHz detunedcarrier
-119 * fPRC
-72 * fPRC
72 * fPRC
119 * fPRC
0
72 D ( 765Hz) D (1.26kHz) D (1.26kHz) 72 D ( 765Hz)
2.2kHz 1.1kHz1.86kHz 2.3kHz
SR-sidebands2kHz detuned
ESF 05 / GEO, B. Willke
Signal Recycling digital
digital loop allows for steep filter
noise contribution reduced by up to a factor of 200
ESF 05 / GEO, B. Willke
Sqrt circuits in MI loop
ESD: F U^2
Sqrt circuits are necessary to give full linear force range for acquisition.
Drawback: sqrt circuits are noisy 1µV/sqrt(Hz)(=100µV/sqrt(Hz) @ ESD)
ESF 05 / GEO, B. Willke
MI loop whitening / dewhitening
dewhiten
dewhiten
dewhiten
Whiten
Whitening right after mixer:zero 3.5 Hzpole 35 Hz
Dewhitening for both split passes
Passive dewhit-ening done in HV path (0-1kV)
ESF 05 / GEO, B. Willke
sensitivity improvements since July
ESF 05 / GEO, B. Willke
102
103
10-21
10-20
10-19
10-18
10-17
Frequency [Hz]
h(t
) [H
z-1/2
]
Jan 02
Aug 02 (S1)
Jan 04 (S3)
Sept 05
Feb 05 (S4)
Aug 04
Evolution of the GEO 600 Sensitivity
ESF 05 / GEO, B. Willke
Current vs. Design sensitivity
102
103
10-24
10-23
10-22
10-21
10-20
10-19
10-18
10-17
Freq. [Hz]
ASD
[h/ H
z]GEO600 Theoretical Noise Budget
SeismicSuspension TNSubstrate TNCoating TNThermorefractiveShot 350HzTotalShot Sept 1 h(t) Sept 1
ESF 05 / GEO, B. Willke
Non-stationary Noise
ESF 05 / GEO, B. Willke
Near Future
finish commissioning increase circulating power find source of optical losses in PR cavity increase MI loop gain between 1-10 Hz improve RF circuitry optimize stability
join S5 in overnight/weekend mode until commissioning is finished
fully join S5
ESF 05 / GEO, B. Willke