Beamsplitter transfer functions have been running over the weekend in order to fix any issues during the day if needed.
The attached pdfs show :
- Comparison between last TF damping on and model
- Comparison between last TF damping off and model
- Comparison between LHO damping on/off and LLO phase 3a (feb 2013) TFs
- Zoomed version of 3.
Vertical degree of freedom is noisier than expected between 1.5 and 3Hz (3rd page of each pdf).
Gerardo went into the chamber, checked the EQ stops, and nothing is apparently touching. When the chamber will be free tomorrow during the day, I will run quick DTT measurements for the vertical degree of freedom, between 1 and 3Hz and see if it's still noisy. There were no need of taking the night for full measurements since the other DOFs are fine. I let the night to Vincent for ISI tfs if needed.
I ran a DTT transfer function on the vertical degree of freedom of the beamsplitter this morning
New TF looks nicer than the old one from April 12th, meaning the beamsplitter is healthy and passed Phase 3a testing
Will run a full set of TF tonight, for our record.
Data of the DTT measurement has been saved in a matlab structure named :M1VtoM1V_20130422.mat under SusSVN/sus/trunk/BSFM/H1/BS/SAGM1/Data and has been commited to the svn
Last measurement on the beamsplitter has been taken monday night April 22nd with damping on and off, before pumping down BSC2 chamber.
- 2013-04-22_1050735424_H1SUSBS_M1_ALL_TFs.pdf shows comparison between transfer function damping on and model
- 2013-04-22_1050717632_H1SUSBS_M1_ALL_TFs.pdf shows comparison between transfer funcion damping off and model
- allbsfms_13_04_22_Phase3a_H1BS_ALL_TFs.pdf shows comparison between model, last LHO measurement April 22nd 2013 and LHO April 12th.
- allbsfms_13_04_22_Phase3a_H1BS_ALL_ZOOMED_TFs.pdf is the zoomed version of the previous plot
One thing to notice :
Vertical degree of freedom remains noisy around 2Hz, as on April 12th, even though dtt transfer function from aLOG 6158 doesn't show any issues. It could be that when taking TF with matlab, the drive for that frequency band is not high enough. I will try with higher gains in the MATLAB_TFs.m script and see if it changes anything.