aLIGO LHO Logbook

H2 SUS

szymon.steplewski@LIGO.ORG - posted 22:42, Friday 24 August 2012 - last comment - 14:32, Monday 27 August 2012(3989)

measured H2 mechanical suspension resonances

In July 2012 the top masses of the quadruple suspensions ITMY and ETMY were excited in order to obtain power spectra from the 24 OSEM sensor readback channels (6 on main chain top, 6 on reaction chain top, 4 on L1 stage, 4 on L2 stage). From these measurements the frequencies of 22 (between 0.1 - 6.0 Hz) out of the 24 mechanical resonances were found. These have been recorded in the aLIGO wiki https://lhocds.ligo-wa.caltech.edu/wiki/mark.barton/ResonanceTest

This wiki page is designed so that when the resonant frequencies of the other suspensions (HSTS , HLTS, BS) or other quadruple suspension resonances are measured they can be easily added to this catalogue of known measured and predicted frequencies. The idea is to have a list of identified features in the spectra of certain known channels, as was done in iLIGO: http://blue.ligo-wa.caltech.edu:8000/iLIGO/H1_Resonances (LVC login). The list may prove useful to aLIGO commissioners or detector characterization scientists trying to track down glitches.

The data and templates for these measurements resides in:

/ligo/svncommon/SusSVN/sus/trunk/QUAD/H2/ETMY/SAGL2/2012-07-25_top_actuation_ETMY_4times_power.xml

/ligo/svncommon/SusSVN/sus/trunk/QUAD/H2/ITMY/SAGL2/2012-07-25_top_actuation_test.xml

Comments related to this report

mark.barton@LIGO.ORG - 04:35, Saturday 25 August 2012 (3990)

Link

Mark B.

Note that while the wiki page https://lhocds.ligo-wa.caltech.edu/wiki/mark.barton/ResonanceTest has been stocked with real SUS data, it is a prototype at an address intended to be temporary and will almost certainly be moved, if it's not reworked as something else entirely, e.g., a full-on database. Do please kick the tires and give me feedback. If you already have data you'd like to add, that could be useful as a test but please ask first. All care will be taken to preserve submissions made during the prototyping period, but there are no guarantees. A further alog comment will be posted here when it's ready for prime time, hopefully in a few days.

mark.barton@LIGO.ORG - 14:32, Monday 27 August 2012 (4000)

Link

The page has now gone live at its production address: 

https://lhocds.ligo-wa.caltech.edu/wiki/Resonances . 

It's intended for recording all LHO resonances (including H1 and H2=OAT, but not L1 or I1).

Note that it now has two script-generated subpages,

https://lhocds.ligo-wa.caltech.edu/wiki/Resonances/SortedBy_fmeas
https://lhocds.ligo-wa.caltech.edu/wiki/Resonances/SortedBy_ftheory

with the same data sorted by f_meas and f_theory. 

The Python scripts used are described at

https://lhocds.ligo-wa.caltech.edu/wiki/Resonances/Scripts

and the scripts themselves are in the attachments.