aLIGO LHO Logbook

H1 SUS

edgard.bonilla@LIGO.ORG - posted 17:17, Tuesday 15 April 2025 - last comment - 12:26, Wednesday 16 April 2025(83940)

In air measurements for PR3 and SR3 OSEM calibration using the ISI

Edgard, Oli

We took measurements to get the above-resonance OSEM response of the PR3 and SR3 suspensions to characterize the gaines. This is a follow up to the in vacuum measurements on 80863, and to the estimated calibrations from 83605.

For PR3, the measurements were taken with

- all of the M1 damping loops at a gain of -0.2 (instead of the nominal -1).
-The coil driver filter in state 1 (similar to the measurements that Jeff took).
- The ISI state was ISOLATED, but HEPI is locked, so we circumvented guardian by sliding off the Isolation Gain on HEPI. This should not affect the measurements for the OSEM calibration.

The results are saved in:
/ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/PR3/Common/Data/

         2025-04-15_1431_H1ISIHAM2_ST1_WhiteNoise_PR3SusPoint_L_0p02to50Hz.xml
         2025-04-15_1431_H1ISIHAM2_ST1_WhiteNoise_PR3SusPoint_T_0p02to50Hz.xml
         2025-04-15_1431_H1ISIHAM2_ST1_WhiteNoise_PR3SusPoint_V_0p02to50Hz.xml

The similarly named _tf.txt files are stored in the same folder, and they export the measured M1 transfer functions using the [ L T V R P Y ] order.

Comments related to this report

oli.patane@LIGO.ORG - 17:26, Tuesday 15 April 2025 (83941)SEI

Link

SR3 Measurements:

all of the M1 damping loops at a gain of -0.2 (instead of the nominal -0.5)
The coil driver filter in state 1
SEI state was ISOLATED, but HEPI is locked, so we circumvented guardian by sliding off the Isolation Gain on HEPI

I had a hard time trying to take data at first (no matter the excitation amplitude we were seeing no movement on the ISI sensors), and we figured out that it was because the SUSPOINT matrix for HAM5 ISI had never been populated! We found the correct matrix values in $(USERAPPS)/isc/common/projections/ISI2SUS_projection_file.mat as ISI2SUSprojections.h1.sr3.EUL2CART, and used /ligo/svncommon/SeiSVN/seismic/Common/MatlabTools/fill_matrix_values.m to fill them in. Then I was able to run the transfer functions.

Data files can be found at /ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/SR3/Common/Data/2025-04-15_2100_H1ISIHAM5_ST1_WhiteNoise_SR3SusPoint_{L,T,V}_0p02to50Hz.xml, and have been committed to svn as r12227.

oli.patane@LIGO.ORG - 10:31, Wednesday 16 April 2025 (83954)

Link

This morning we decided to do the rest of the DOFs for the SUSPOINT to M1 measurements of PR3 and SR3.

For SR3:

Same setup as before:

all of the M1 damping loops at a gain of -0.2 (instead of the nominal -0.5)
The coil driver filter in state 1
SEI state was ISOLATED, but HEPI is locked, so we circumvented guardian by sliding off the Isolation Gain on HEPI

Data files can be found at /ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/SR3/Common/Data/2025-04-15_2100_H1ISIHAM5_ST1_WhiteNoise_SR3SusPoint_{R,P,Y}_0p02to50Hz.xml, and have been committed to svn as r12232.

edgard.bonilla@LIGO.ORG - 12:26, Wednesday 16 April 2025 (83955)

Link

For PR3:

Same setup as before:

all of the M1 damping loops at a gain of -0.2 (instead of the nominal -0.5)
The coil driver filter in state 1
SEI state was ISOLATED, but HEPI is locked, so we circumvented guardian by sliding off the Isolation Gain on HEPI

Data files can be found at /ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/PR3/Common/Data/2025-04-15_1431_H1ISIHAM5_ST1_WhiteNoise_SR3SusPoint_{R,P,Y}_0p02to50Hz.xml, and have been committed to svn as r12249.