July 24, e2e LIGO 1 meeting
e2e simulation group activity summary
e2e modeling
1) LSC modeling by Luca
2) Curvature mismatch
* validation and bug fix completed for FP
* moving toward PRM
3) signal generation (Kathy : SURF student)
* detector orientation and correlation
* data file which e2e will read
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Next actions
1) Mechanics model
* obtain ground motion spectrums of LHO and LLO (day&night) (Robert)
* combine 6x6 stack transfer function
* compare with Engineering run data to validate the model (Stan, Luca)
* can the different of the locking status of LLO between day and night
simulated ?
2) Simulation of today's noise curve
* noisy LSC
* measured noise of later going into RM
* calculate the noise curve from the dark port output
3) PRM mode study
* compare data, FFT and e2e to find how many modes are necessary
4) Inclusion of mirror imperfections
* GaryLynn will provide data by the end of August
* lower order mode decomposition matrix
* cavity asymmetry
5) release of new e2e package by mid August
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Alfi : Graphical User Interface of e2e
A design and development of a new version has started.
One major goal is to make it more stable and less picky about OS/versions
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Brief summaries by Luca, Biplab and Virginio
1) LSC modeling : Luca
2) PSL noise study : Biplab
3) Mechanics modeling : Virginio (quadruple adv. LIGO suspension)
Luca Matone : Modeling of realistic noisy LSC
List of measurements done so far on the 2k reflection port:
o Demodulator Board (I)
- Noise floor measured;
o Whitening Board
- Noise floor measured for different gain settings;
- TF with whitening filters on/off;
o Anti-Aliasing Board
- TF with AA filter enabled (Nergis 2000);
o Anti-Imaging Board
(- theoretical TF from schematics);
o Digital filters
- TF measured and traced the corresponding TF coefficients of
+ 0.1:10;
+ 1k:10,100;
+ 15:150;
+ 1:20;
+ 13HzRG;
+ 1k:10;
+ 2kBW;
- traced the filter coefficients of
+ inverse of Whitening board;
+ inverse of De-Whitening Board : dewhite1, dewhite2,
dewhite3, dewhite4;
+ stopband (SB and Cheby);
o Anti-Image (output) and Whitening Board (input) (PENTEK 6102)
- TF w/o Whitening filters on, w/o AA;
- Noise floor;
o De-Whitening Board
(- theoretical TF from schematics and from inv(dewhite));
o Noise floor of H2:LSC-REFL_I when
- light on PD is blocked;
- whitening filter enabled/disabled;
Measurements still to be done:
o Anti-Imaging Board TF and noise floor;
o Stopband digital filters TF;
o De-Whitening Board TF and noise floor;
Biplab Bhawal : Study of PSL FSS noise due to higher order modes:
(with Brad Zamft and Rick Savage)
* Studied the effects of the presence of higher order modes in input
beam on frequency sensor noises.
* The Reference cavity of FSS of PSL is a symmetric one and so all
higher order modes in both carrier and sidebands get reflected from
it and fall on RFPD and beat with each other to give rise to signal
which may be falsely assumed to be due to frequency shift and so
acts as a source of noise.
* Studied the effects of PD motion or shift (longitudinal and transverse)
and also nonuniformity in its responses with some realistic parameters.
* Our estimate, for example, in case of a 3 beam-width PD whose response
function looks like a tilted surface with 1% variation across it and
which is moving transversely with 1e-8 m/rtHz motion, is about one order
of magnitude lower than the LIGO design requirement ( 1e-2 Hz/rtHz at 1 kHz).
In other studied cases this level is lower and, especially for longitudinal
motion of PD, it's of the order of the shot-noise limit (4e-5 hz/rtHz)
or below it.
Detector Experts
Robert Schofield
Integration of environmental effects into the e2e model.
Spectra for normal seismic, acoustic, etc. environments
at LHO and LLO have been assembled into a document available at:
http://www.ligo.caltech.edu/~dhs/Adv-LIGO/T010074-01-D.pdf
Links to some original time series are also included.
Measurements of transfer functions to the interferometer have begun.
Day and
night different << surf
correlation
tilt <<
Peter King
Data gathering for the LLO PSL will commence shortly. Until late
last night the laser was not available and earlier the laser was not
available outside the hours of 9pm to 8am. In any case, I hope to finish
the following measurements before the end of this week.
i. laser free-running intensity noise
ii. relative intensity noise (RIN) just before suspended modecleaner
iii. RIN transmitted by the MC
iv. free-running frequency noise
v. frequency noise as measured by the MC - provided we manage to
pump down this week
David Reitze
IO e2e - Most of the activity at Hanford has been centered on restoring
the 2K MC to a quiet operating state (leveling), upgrading MC electronics
(installation of bounce mode notch filters, reparation of other
components). High power operation has been tested and work; new
OSEMS are ~ 300 times less senstive to to 1.06 um light. Efforts at
LLO are underway to realign and relock the MC.