10meter Interferometer Results

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10-meter Interferometer Results
M. Woods (special thanks to Steve Myers and Tim
Slaton) Jan. 31, 2000
Commissioning Setup System Noise Monte Carlo
simulation Temperature sensitivity Study of
frequency sweeping, matching interferometer arm
lengths Stability and response with piezo
excitation on one end mirror
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Optical Anchor Overview
Optical Anchor Schematic
Interaction Region Schematic
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Interferometer Schematic
l1 L1 dl1 l2 L2 dl2 dl dl1 - dl2
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(No Transcript)
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Measuring the displacement, dl (cont.)
In practice, we do the following
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Laser Requirements
1. Laser Power want photon statistics
adequate up to 100 Hz Nggt (dF)-2 for T
0.01s
2. Laser Intensity Stability DI/I lt dF
3. Laser Frequency Stability let (l1-l2) lt 1cm
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Environmental Requirements
a airSTP 1.1 x 10-4 HeSTP 1.3 x 10-5
Let dn be change in relative index of refraction
for 2 arms dP, dT be changes in relative
pressure, temperature for 2 arms
dP lt 2.7 x 10-4 Torr (air) 2.3 x 10-3
Torr (He) dT lt 1 x 10-4 oK (air) 9 x
10-4 oK (He)
(but slow drifts are acceptable)
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10-meter Interferometer
Test Setup in Sector 10 Alignment Room
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Photodiode Array Mean Signals
Beam B
Beam A
Beams A and B
Nov. 2, 1999 Runs 5A, 5B, 5AB
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rms 0.2nm
Measured Displacement over 100 seconds
Nov. 2, 1999 Run 5AB 256 Hz DAQ
Photodiode Signals over 100 seconds
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Power Spectra for Photodiode Array Signals
Nov. 2, 1999 Run 5AB
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Integrated Power Spectra for Photodiode Array
Signals
Nov. 2, 1999 Run 5AB
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Nov. 2, 1999 Run 5AB
Displacement Power Spectra and Integrated Power
Spectra
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Photodiode Array Mean Signals Monte Carlo
Simulation
Beam A
Beam B
Beams A and B
Run MC001
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Input Displacement over 100 seconds
Reconstructed displacement over 100 seconds
Run MC001 10nm ramp over 100 seconds 0.2nm input
jitter per point 256 Hz DAQ
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Residual displacement vs input displacement with
10 error in photodiode spacing
Residual (measured - input) displacement vs input
displacement (photodiode spacing correct)
Monte Carlo simulation
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Run MC001
Photodiode Signals over 100 seconds
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Run MC001
Displacement Power Spectra and Integrated Power
Spectra
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Measured Displacement over 100 seconds
Nov. 21, 1999 Run 3AB 256 Hz DAQ
Photodiode Signals over 100 seconds
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Power Spectra for Photodiode Array Signals
Nov. 21, 1999 Run 3AB
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Nov. 21, 1999 Run 3AB
Displacement Power Spectra and Integrated Power
Spectra
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Measured Displacement over 15 hours
Nov. 4, 1999 Run 2AB 1 Hz DAQ
Photodiode Signals over 15 hours
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Nov. 2, 1999 Run 1AB 1 Hz DAQ (Avg 100 pts
offline)
Nov. 11, 1999 Temprun1 0.5 Hz DAQ (Avg. 100 pts
online)
Sector 10 Room Temperature over 20 hours
Sector 10 Room Temperature over 40 hours
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Studying Temperature Effects on Interferometer
Stability
B
A
Nov. 11, 1999 Run 2AB
Nov. 11, 1999 Run 3AB
30 seconds into run, put 1 fingertip on one of
the 3 beamlines (A,B,C) for 30 seconds. (C is
the common beamline before the beamsplitter.)
C
Nov. 11, 1999 Run 4AB
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Studying Frequency Sweeping effects of Laser with
and without mismatch in lengths of interferometer
arms
1 length mismatch
No length mismatch
Nov. 11, 1999 Run 10AB
Nov. 11, 1999 Run 6AB
Prior to these runs, the laser was turned off for
60 seconds and then on for 60 seconds. Then the
run is started. This results in laser not being
frequency-stabilized during run.
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Piezo installed on end mirror for Interferometer
Arm B
Nov. 21, 1999 Run 9AB
Nov. 21, 1999 Run 11AB
10 Hz Sine Wave
10 Hz Square Wave
2560 Hz DAQ for 1-second for these 2 runs
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SUMMARY
System Resolution/Noise - typically IPS(1Hz) lt
0.5nm this is adequate for initial
prototyping and interfacing with quad
simulator - have demonstrated adequate
resolution/noise for 10-meter arms and
with anchoring of optics to floor - these good
results are achieved in a good lab setting, ie.
Sector 10 Alignment Room -- IPSfloor(3Hz) lt
10nm, and very good temperature stability
(lt0.3degC over 24 hours) - for actual IR
installation, expect will need vacuum in the
interferometer arms (or at least very good
thermal isolation) MonteCarlo simulation gives
reasonable modeling of results Demonstrated use
of laser frequency sweeping to study matching of
interferometer arm lengths Demonstrated good
sensitivity and low noise with piezo actuator on
an end mirror For future - Tom Mattison is
taking over this interferometer operation - it
is ready for development of piezo excitation /
feedback and for integration with a quad
simulator