jeffrey.garcia@LIGO.ORG - posted 10:37, Thursday 31 May 2012 - last comment - 16:14, Friday 01 June 2012(2991)
H2 SUS ITMY, 2012-05-29 Measurements
J. Garcia, S. Steplewski We made a set of TOP transfer function measurements on ITMY Tuesday. This was the first time we tested ITMY since this chamber was pumped down. Measurements were clean and the results match up reasonably well with the (fiber) model - although this is a wire rehang after the fiber break. The .mat files are located in: ~/SusSVN/trunk/QUAD/H2/ITMY/SAGM0/Data/ ~/SusSVN/trunk/QUAD/H2/ITMY/SAGR0/Data/ The .pdf files are located in: ~/SusSVN/trunk/QUAD/H2/ITMY/SAGM0/Results ~/SusSVN/trunk/QUAD/H2/ITMY/SAGR0/Results
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Attached is another plot that shows the ITMY TOP transfer function taken In-Vacuum compared to that taken In-Air. Aslo plotted are the wire (for M0) and thincp (for R0) models for reference.
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Mark Barton, Szymon Steplewski We changed the parameters in the Mathematica model for the QUAD suspension for ITMY to reflect the fact that the glass test mass is suspended from steel wires after the fiber break. These changes have resulted in noticeably better agreement between the measurements and model for several degrees of freedom. The TOP Pitch to Pitch mode around 1.4 Hz has shifted to higher frequency (from about 1.31 Hz to 1.44 Hz), while the Pitch mode near 0.56 Hz is practically unchanged, which is where we want it according to the design requirements. The TOP Longitudinal to Longitudinal plot also shows some nice improvement in the mode around ~1.5 Hz, which matches up a little more with the "wirerehang" model now. There is now a new wirerehang Mathematica model in the SUS SVN under ~/trunk/Common/MathematicaModels/QuadLite2Lateral/mark.barton/20120601TMproductionTMrehang/ which was built from elements of the fiber model under ~/trunk/Common/MathematicaModels/QuadLite2Lateral/mark.barton/20120601TMproductionTM/ We have added 'wirerehang' to the list of case models for plotting in Matlab, so the different cases are now: 1. 'wire' 2. 'fiber' 3. 'erm' 4. 'thincp' 5. 'wirerehang'
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