Документ взят из кэша поисковой машины. Адрес оригинального документа : http://zebu.uoregon.edu/~uochep/talks/talks08/G080214-00.pdf Дата изменения: Wed Jan 21 23:02:15 2009 Дата индексирования: Tue Oct 2 11:29:08 2012 Кодировка: Поисковые слова: voyager

S5 Upconversion DQ Flags

Masahiro Ito U of Oregon L-V Meeting March 19, 2008

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Upconversion flags
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Upconversion flags by coil current (0.1-40Hz)

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Flag the times that low frequency seismic signals disturb the IFO sensitivity H1:SUS-ETMY_COIL_LL Flags for S5 2nd year done Re-run with updated scaling function in progress

Compressor noise at optics roll mode frequency (~18Hz) H2:DARM_ERR, H0:LVEA_SEISZ Compressor motor noise at LHO staging building in progress

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Flag by coil current

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Use H1:SUS-ETMY_COIL_LL for coil current Find conversion factor from selected coil peaks to H1:DARM_ERR signal Make a fit curve to the conversion factors -> Scaling function, w(f) Calculate band limited RMS data with the scaling function

Make a threshold for the scaled BLRMS

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Peaks in the H1:SUS-ETMY_COIL_LL spectrum

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Finding how coil current at different frequencies affects H1:DARM_ERR
11/9/06 - 11/19/06 Slope of the fit line becomes conversion factor from coil to H1:DARM_ERR at this frequency

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A fit to slopes for the different frequencies gives a scaling function of ~f^0.5 in current amplitude (~f in RMS^2)
X Slopes for test segments

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Most of the flags in the high micro-seismic peak period
74.3% of flags in Dec. 2006

RMS

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RMS

2

RMS

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Less flags in low micro-seismic peak period
0.314% of flags in Jul. 2007

RMS

2

RMS

2

RMS

2

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Updating scaling function

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The scaling function for the first run of S5 didn't include the second mechanism of the upconversion (>10Hz) -> Require an updated scaling function Use data for entire S5 to generate the updated function

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Updated scaling function

Second structure of upconversion included

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To do
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Estimate the noise in terms of strain or displacement Make flags for entire S5 with revised scaling function

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Threshold by strain/displacement amplitude Threshold based on running statistics Multiple thresholds Include ITM damping currents

Study overlap with other flags Make flags for LLO

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......

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Flag for compressor noise (in progress)

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A source of upconversion noise Compressor motor at the LHO staging building ~30 minutes period repeats several cycles The seismic noise at optics roll mode frequecy 17~18Hz Appeared in H2:DARM_ERR at ~17.27Hz, ~34.54Hz (2nd harmonic)

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Compressor noise frequency drift down with ~30-min. period

elog: 4/21/2007 by R.Schofield
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Two roll mode peaks in the GW channel at 17-18Hz
17.6Hz 17.27Hz
H2 Strain Sensitivity

Strain/Sqrt(Hz)

Frequency (Hz)
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DARM_ERR gets peaks when seismic signal at roll mode frequency

17.6Hz roll mode

17.27Hz roll mode
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Summary

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Coil upconversion flags for S5 2nd year is available as "COIL_UPCONVERSION" Generation of the coil upconversion flags with updated scaling function for entire S5 is in progress Upconversion flags with thresholds other than 1% dead time are planned Compressor noise flag for H2 is under investigation for channels and bands that efficiently flag the event

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