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Message ID: 86     Entry time: Fri Nov 9 00:01:24 2007
Author: waldman 
Type: Omnistructure 
Category: OMC 
Subject: OMC mechanical resonances (Tap tap tappy tap) 
[Pinkesh, Aidan, Sam]

We did a tap-tap-tappy-tap test of the OMC to try to find its resonances. We looked at some combination of the PDH error signal and the DCPD signal in a couple of different noise configurations. The data included below shows tapping of the major tombstone objects as well the breadboard. I don't see any strong evidence of resonances below the very sharp resonance at 1300 Hz (which I interpret as the diving board mode of the breadboard). If I get free, I 'll post some plots of the different breadboard resonances you can excite by tapping in different places.

(The "normalized" tapping response is abs(tap - reference)./reference.)
Attachment 1: Fig1.png  155 kB  | Hide | Hide all
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Attachment 2: Fig2.png  165 kB  | Hide | Hide all
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Attachment 3: Fig4.png  166 kB  Uploaded Fri Nov 9 08:48:17 2007  | Hide | Hide all
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Attachment 4: Fig2.pdf  50 kB  Uploaded Fri Nov 9 08:48:43 2007  | Hide | Hide all
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Attachment 5: Fig1.pdf  50 kB  Uploaded Fri Nov 9 08:48:53 2007  | Hide | Hide all
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Attachment 6: Fig4.pdf  62 kB  Uploaded Fri Nov 9 08:50:42 2007  | Hide | Hide all
Fig4.pdf
Attachment 7: ResonanceData.zip  9.535 MB  Uploaded Fri Nov 9 08:50:55 2007
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