aLIGO LHO Logbook

H1 SYS (SEI)

jim.warner@LIGO.ORG - posted 15:14, Thursday 14 December 2017 - last comment - 08:28, Friday 15 December 2017(39765)

HAM2 & HAM5 table baffle B&K measurements

I'm posting the BnK measurements of the HAM2 & HAM5 table baffles. I've split the plots up into similar structures (Plus/Minus X/Y beard baffles, Middle beard Baffles, HAM2 table top baffles, HAM5 table top baffles) and equivalent excitations/accelerometer orientation relative to "beamline" (X for HAM2, Y for HAM5). I'm using Jeff's names for the baffles, so Table baffles are the beard baffles. Table Top baffles are the table baffles that typically lie flat on the ISI optics table in front of the suspensions. It looks like I grabbed the wrong data for the MC1 Table Top baffle, so I need to look into that some more.

Most of the well resolved stuff seems to be well damped, I don't think I saw any of the low frequency (50-60 hz stuff) on the first plot in the HAM5 or HAM2 ISI tfs. The sharp 120 hz feature on the HAM5 MinusX table baffle is worrying, but there was probably a lot of loose mass on the table at the time. The HAM5 measurements are from Dec 6, before Hugh and Brijesh balanced that table.

I've put the txt BnK exports in the Seismic SVN at:

/ligo/svncommon/SeiSVN/seismic/HAM-ISI/H1/Common/Data/HAMBnK_measurements/HAM2/

The script I made the plots with is at:

/ligo/svncommon/SeiSVN/seismic/HAM-ISI/H1/Common/Data/HAMBnK_measurements/HAM2_table_baffles.m

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Comments related to this report

hugh.radkins@LIGO.ORG - 08:28, Friday 15 December 2017 (39775)

Link

As far as the HAM5 table goes--I cleaned up the table and bolted down and viton'd the table top masses on Dec1. However, on Dec7, GM found the new ZM2 mirror and the Septum Beam dump needing torquing.