A couple months ago (86253) I posted a huge list of all of the results from the satamp swaps that we had done up to that point. We've done some more swaps, so I have more results.
Swapped Sept 23, 2025 (87103)
PRM M2, M3
SRM M2, M3
BS M2
ITMX L1
ITMY L1
ETMY L1
PRM
swapped stages as of now: M1*, M2, M3 (* means swapped prior to 09/23)
M2
Data:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PRM/SAGM2/Data/dampRegress_H1SUSPRM_M2_1442053782_1200.mat r12671
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PRM/SAGM2/Data/dampRegress_H1SUSPRM_M2_1442692939_1200.mat r12671
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PRM/SAGM2/Results/allDampRegressCompare_H1SUSPRM_M2_NoiseComparison_1442053782vs1442692939-1200.pdf r12671
M3
Data:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PRM/SAGM3/Data/dampRegress_H1SUSPRM_M3_1442053782_1200.mat r12672
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PRM/SAGM3/Data/dampRegress_H1SUSPRM_M3_1442692939_1200.mat r12672
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PRM/SAGM3/Results/allDampRegressCompare_H1SUSPRM_M3_NoiseComparison_1442053782vs1442692939-1200.pdf r12672
SRM
swapped stages as of now: M1*, M2, M3
M2
Data:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SRM/SAGM2/Data/dampRegress_H1SUSSRM_M2_1442053782_1200.mat r12673
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SRM/SAGM2/Data/dampRegress_H1SUSSRM_M2_1442692939_1200.mat r12673
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SRM/SAGM2/Results/allDampRegressCompare_H1SUSSRM_M2_NoiseComparison_1442053782vs1442692939-1200.pdf r12673
M3
Data:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SRM/SAGM3/Data/dampRegress_H1SUSSRM_M3_1442053782_1200.mat r12674
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SRM/SAGM3/Data/dampRegress_H1SUSSRM_M3_1442692939_1200.mat r12674
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SRM/SAGM3/Results/allDampRegressCompare_H1SUSSRM_M3_NoiseComparison_1442053782vs1442692939-1200.pdf r12674
BS
swapped stages as of now: M1*, M2
M2
Still a bit noisy, but these were the quietest times we have where we didn't have anything coming out of DRIVEALIGN
Data:
/ligo/svncommon/SusSVN/sus/trunk/BSFM/H1/BS/SAGM2/Data/dampRegress_H1SUSBS_M2_1432488116_720.mat r12687
/ligo/svncommon/SusSVN/sus/trunk/BSFM/H1/BS/SAGM2/Data/dampRegress_H1SUSBS_M2_1443899058_720.mat r12687
Results:
/ligo/svncommon/SusSVN/sus/trunk/BSFM/H1/BS/SAGM2/Results/allDampRegressCompare_H1SUSBS_M2_NoiseComparison_1432488116vs1443899058-720.pdf r12687
ITMX
swapped stages as of now: R0*, M0*, L1
L1
Data:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL1/Data/dampRegress_H1SUSITMX_L1_1442007359_1200.mat r12675
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL1/Data/dampRegress_H1SUSITMX_L1_1442833698_1200.mat r12675
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL1/Results/allDampRegressCompare_H1SUSITMX_L1_NoiseComparison_1442007359vs1442833698-1200.pdf r12675
ITMY
swapped stages as of now: R0*, M0*, L1
L1
** There is an issue with the satamp (S1100129) we swapped in here. There is elevated noise above 10 Hz, as can be seen in the plots. There are also spikes in noise above 10 Hz in the 'after' traces that aren't seen in the 'before' traces. This noise is seen in every 'after' time I tried, but not seen in any 'before' times. The issue looks to be in the UR channel (diaggui1, diaggui2). We will be trying to fix this by power cycling the satamp, otherwise we will swap it out with another satamp.
Data:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGL1/Data/dampRegress_H1SUSITMY_L1_1442007359_900.mat r12681
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGL1/Data/dampRegress_H1SUSITMY_L1_1442892252_900.mat r12681
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGL1/Results/allDampRegressCompare_H1SUSITMY_L1_NoiseComparison_1442007359vs1442892252-900.pdf r12681
ETMY
swapped stages as of now: R0*, M0*, L1
L1
Data:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMY/SAGL1/Data/dampRegress_H1SUSETMY_L1_1442052701_1200.mat r12686
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMY/SAGL1/Data/dampRegress_H1SUSETMY_L1_1443890298_1200.mat r12686
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMY/SAGL1/Results/allDampRegressCompare_H1SUSETMY_L1_NoiseComparison_1442052701vs1443890298-1200.pdf r12686
Swapped Sept 30, 2025 (87225)
PR2 M2, M3
SR2 M2, M3
PR2
swapped stages as of now: M1*, M2, M3 (* means swapped prior to 09/30)
M2
Data:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PR2/SAGM2/Data/dampRegress_H1SUSPR2_M2_1442539459_1200.mat r12682
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PR2/SAGM2/Data/dampRegress_H1SUSPR2_M2_1443551029_1200.mat r12682
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PR2/SAGM2/Results/allDampRegressCompare_H1SUSPR2_M2_NoiseComparison_1442539459vs1443551029-1200.pdf r12682
M3
Data:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PR2/SAGM3/Data/dampRegress_H1SUSPR2_M3_1442539459_1200.mat r12683
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PR2/SAGM3/Data/dampRegress_H1SUSPR2_M3_1443551029_1200.mat r12683
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PR2/SAGM3/Results/allDampRegressCompare_H1SUSPR2_M3_NoiseComparison_1442539459vs1443551029-1200.pdf r12683
SR2
swapped stages as of now: M1*, M2, M3
M2
Data:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM2/Data/dampRegress_H1SUSSR2_M2_1443134194_1200.mat r12684
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM2/Data/dampRegress_H1SUSSR2_M2_1443463761_1200.mat r12684
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM2/Results/allDampRegressCompare_H1SUSSR2_M2_NoiseComparison_1443134194vs1443463761-1200.pdf r12684
M3
Data:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM3/Data/dampRegress_H1SUSSR2_M3_1443134194_1200.mat r12685
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM3/Data/dampRegress_H1SUSSR2_M3_1443463761_1200.mat r12685
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM3/Results/allDampRegressCompare_H1SUSSR2_M3_NoiseComparison_1443134194vs1443463761-1200.pdf r12685
With help from TJ, I migrated a majority of the ASC filters controlled by ISC_LOCK into an lscparams dictionary called asc_filters, and edited the filter engagement/disengagement commands in the guardian to call from this dictionary. Along the way, I also edited the lscparams asc_gains dictionary, and removed commented out code that seemed unnecessary or out of date.
New practice: each dictionary entry in asc_filters includes ALL filter bank settings that should be ON at a given time, so all filters to be engaged as well as OUTPUT, DECIMATION (INPUT as well, if it is supposed to be on). When filter changes are made, we can use the command ezca.get_LIGOFilter([DOF]).only_on(*lscparams.asc_filters[DOF][P/Y][NAME]). The names of the filter settings are named after the guardian state in which they are engaged, with some small edits if one guardian state has multiple filter engagement steps.
Example:
In PREP_ASC_FOR_FULL_IFO, CSOFT P filters are set up, but the input is left off until engagement in ENGAGE_SOFT_LOOPS. Then, after the loop is engaged and converged, FM1 is disengaged. Finally, in POWER_25W, FM3 is engaged as a boost.
The dictionary is set up as:
'CSOFT':{'P':{'PREP_ASC_FOR_FULL_IFO': ['FM1', 'FM6', 'FM7', 'OUTPUT', 'DECIMATION'],
'ENGAGE_SOFT_LOOPS': ['FM1', 'FM6', 'FM7', 'INPUT', 'OUTPUT', 'DECIMATION'],
'ENGAGE_SOFT_LOOPS_final': ['FM6', 'FM7', 'INPUT', 'OUTPUT', 'DECIMATION'],
'POWER_25W': ['FM3', 'FM6', 'FM7', 'INPUT', 'OUTPUT', 'DECIMATION'],
},
In PREP_ASC:
ezca.get_LIGOFilter('ASC-CSOFT_P').only_on(*lscparams.asc_filters['CSOFT']['P']['PREP_ASC_FOR_FULL_IFO'])
ezca.get_LIGOFilter('ASC-CSOFT_P').only_on(*lscparams.asc_filters['CSOFT']['P']['ENGAGE_SOFT_LOOPS']) # turn on input
ezca.get_LIGOFilter('ASC-CSOFT_P').only_on(*lscparams.asc_filters['CSOFT']['P']['ENGAGE_SOFT_LOOPS_final']) # turn off FM1
ezca.get_LIGOFilter('ASC-CSOFT_P').only_on(*lscparams.asc_filters['CSOFT']['P']['POWER_25W']) # engage resG
Therefore, when we make adjustments to ASC filters or gains, we will need to edit the dictionaries in lscparams. This will ensure that any changes also get picked up by the seismic guardian.
These are things that are not yet controlled by this dictionary:
TJ is currently editing the seismic guardian to create the ASC higain state and then a state that takes ASC back to its lownoise state. Now, we can pull the gain and filters settings from these dictionaries!
Two errors:
I made a typo that called "SRC2" instead of "SRC1", luckily this just caused a guardian error and not a lockloss. Fixed.
I missed a DHARD P filter engagement in RESONANCE, which meant that the guardian disengaged this filter later on. This surprisingly did not cause an error until LOWNOISE_ASC, when the final loop shaping engaged and caused a lockloss. Fixed.
Success after second locking attempt. I checked in the changes to lscparams and ISC_LOCK into the SVN.
WP12827 HLTS Estimator h1sus[pr3,sr3]
Jeff, Edgard, Brian L, Corey, Oli, Jonathan, Erik, Dave:
We installed Stanford's new h1sus[pr3,sr3] models and new MEDM screens. Each model added 255 slow and 37 fast channels to the DAQ. All the fast channels are acquired at 512Hz.
DAQ Restart
Jonathan, Dave:
The DAQ was restarted for the above model changes. No major issues, but both GDS needed a second restart.
Tue07Oct2025
LOC TIME HOSTNAME MODEL/REBOOT
10:03:55 h1sush2a h1suspr3 <<< PR3
10:04:46 h1sush56 h1sussr3 <<< SR3
10:06:34 h1daqdc0 [DAQ] <<< 0-leg
10:06:45 h1daqfw0 [DAQ]
10:06:46 h1daqtw0 [DAQ]
10:06:47 h1daqnds0 [DAQ]
10:06:55 h1daqgds0 [DAQ]
10:07:27 h1daqgds0 [DAQ] <<< 2nd gds0 restart
10:10:46 h1daqdc1 [DAQ] <<< 1-leg
10:10:55 h1daqfw1 [DAQ]
10:10:56 h1daqtw1 [DAQ]
10:10:58 h1daqnds1 [DAQ]
10:11:05 h1daqgds1 [DAQ]
10:11:44 h1daqgds1 [DAQ] <<< 2nd gds1 restart
The front bearing on the de-energized fan at End X was replaced this morning. The fan was jogged to ensure the vibration was resolved.
M. Todd, C. Compton, S. Dwyer
I followed the steps layed out in alog 87316, and ran into OM suspension saturations before getting to start my measurement. I turned off the centering loops and cleared the integrators (you have to turn off OMC ASC and hit graceful clear history as well). Then turning them back on they seemed fine. I turned on the OMC ASC and set the LSC offset appropriately and then went out and turned off the sidebands.
We took scans for ITMX and ITMY about 25 minutes after the unlock, so we call this the HOT-ish (tepid) scan with CO2s on.
We then waited an hour with the ITMs realigned so that the HWS could track the defocus before taking another set of OMC scans.
We then turned the CO2s off and left the HWS aligned to watch the defocus change from them. ITMX HWS did not show a lot of change so upon examination it seems the SLED source is either dying or the CO2 is misaligned. TJ and Camilla are working on replacing the source to see if that will remedy things.
After an hour with the CO2s off we repeated the scans for each test mass for the final measurements.
Analysis will follow in a comment but I've attached the DTT screenshot below.
Matt, TJ, Sheila, Camilla
Today Sheila and Matt have been doing some IFO/CO2/OMC scan tests, in doing this we noticed the CO2X looked very misaligned, plots of CO2. However the SLED has degraded v. quickly since it was last swapped May: 84417, and even the IFO beam plots (120s and 7minutes) look a little strange and clipped.
We plan to replace this SLED before we decide if the CO2X is really misaligned or not. Procedure to realign CO2s with picos is: 68391, most recently blasted 2W for 2mins and waited ~10mins between pico moves. Last checked Oct 2024 80834 for ITMY and March 2024 for ITMX 75987
After TJ and I replaced the ITMX SLED 87353, the ITMX CO2 alignment looks a lot better now, I don't think it needs to be adjusted.
I blasted 2W of CO2 for 2 minutes on ITMX and ITMY in turn, attached is HWS images, red cross is IFO beam position we want OC2 centered around.
J. Oberling, R. Short
After the PSL pump diode operating current increase earlier this morning, we performed a rotation stage calibration. The curve is attached, as well as the SDF update. New parameters:
Tue Oct 07 10:04:49 2025 INFO: Fill completed in 4min 46secs
Gerardo confirmed a good fill curbside.
J. Oberling, R. Short
This morning we tweaked the operating current of the PSL 4S-HP amplifier pump diodes; this was done with the ISS OFF. The tweaks can be seen in the attached plot. End numbers:
With the ISS back ON, we had to decrease the RefSignal to -2.01 V to put the diffracted power % back at our usual 4% (this is due to the increase in power out of the PMC).
To end, we took the opportunity to tweak the beam alignment into the RefCav. We started with a TPD of ~0.533V, and ended with a TPD of ~0.55V.
A rotation stage calibration will need to be performed due to the increased power out of the PMC.
Did the Dust Monitor Check and a new (to me atleast) problem would be for DR2 (Diode Room 2).
TITLE: 10/07 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 2mph Gusts, 1mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.13 μm/s
QUICK SUMMARY:
First things first, at Camilla's request, I did a PAUSE for TCS_ITM[x/y]_CO2_PWR Guardians---this was for a possible Matt T. test (he just walked in and was hoping for a recently-thermalized H1, but H1is only at NLN for 1.25hrs (he's contacting Sheila).
Other than that, preparing for Maintenance!
P.S. There was a dust alarm for one of the Optics Labs when I arrived
Notes On H1 Overnight: NO Wake-Up Calls; Lockloss down from 1131-1331utc (due to earthquake dropping H1 +L1); Reacquisition AUTOMATIC (no alignment run); H1 was then locked about 90min before it was intentionally unlocked for Maintenance.
Workstations were updated and rebooted. This was an OS packages update. Conda packages were not updated.
TITLE: 10/07 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
INCOMING OPERATOR: TJ
SHIFT SUMMARY:
Super Event Candidate: S251006dd !
Other than that it was a very quiet night, H1 has been locked for 10 hours without issue.
Note to the morning ops:
Please pause the Co2_PWR guardian before lockloss this Tuesday, see mattermost.
LOG:
No Log
Made a modification to the library parts needed for adding an OSEM estimator to the Length degree of freedom for the HLTS models. The change comes with an addition of a few DQ channels, listed on the.txt attached. This work is part of the ECR summarized here: E2500251.
The library parts modified live in /opt/rtcds/userapps/trunk/sus/common/models/ , they are HLTS_MASTER_W_EST.mdl and SIXOSEM_T_STAGE_MASTER_W_EST.mdl.
The changes were committed to the userapps svn under revision 33319.
Summary of changes:
SIXOSEM_T_STAGE_MASTER_W_EST.mdl
Changed the ADD block to fork the Longitudinal drive into a light-damping and an estimator path, in line with the rest of the estimator infrastructure already in place for Pitch and Yaw. Notably, we added epics outputs ADD_L_ISC_MON and ADD_L_EST_MON in addition to the old ADD_L_TOTAL_MON inside the ADD block.
Added a testpoint for the total longitudinal drive inside the ADD block. ADD_L_TOTAL
Changed the input wiring to the DELAY block so the estimator L drives are the ones that go into the block and back to the EST subsystem.
HLTS_MASTER_W_EST.mdl
List of new DQ channels:
The attached text file lists both the PR3 and SR3 channels that we will be adding with the aforementioned model changes.. All new DQ channels are sampled at 512 samples/second.
I have updated the MEDM screens to include the Length estimator, and I've fixed a few little things along the way.
You will need to $ svn up the ...userapps/trunk/sus/common/medm/ directory to get the changes
I've updated these screens:
sus/common/medm/
hxts/SUS_CUST_HLTS_OVERVIEW_W_EST.adl
estim/ESTIMATOR_OVERVIEW.adl
estim/FADE_CONTROL.adl
estim/CONTROL_6.adl
updated the SUS_CUST_HLTS_OVERVIEW_W_EST.adl screen
- fixed the indicator for the estimators. Green = ON, grey = off
- added Len estimator
- moved things just a bit so that everything fits
- left the 3 estim indicators as separate buttons because they launch separate related displays.
updated ESTIMATOR_OVERVIEW.adl
- fixed channel names for the indicator on the fader switch (was ...SWITCH_FADE_blah_blah_MON, now is ...SWTICH_MON_blah_blah)
This model change happened a while ago. I guess we missed the MEDM update then
fixed the FADE_CONTROL.adl screen with new names per the ESTIMATOR_OVERVIEW
(these are in revision 33320)
I also fixed the state indicators in the CONTROL_6 screen and the ESTIMATOR_OVERVIEW screen
The indicator is GREY if the output button is OFF
In the MEDM text file it looks like this:
"basic attribute" {
clr=7
}
"dynamic attribute" {
vis="calc"
calc="(A&1024) == 0"
chan="$(IFO):SUS-$(OPTIC)_M1_EST_$(DOF)_FUSION_MODL_SUSP_T_2GAP_SW2R"
This needs to be the top layer.
if the output is ON, then the display is green/ red if the state is good/bad.
The state indicator updates to the MEDM repo are -r 33321 for the CONTROL_6 screen and -r 33322 for the ESTIMATOR_OVERVIEW screen
share and enjoy!
M. Todd, S. Dwyer
I'm sure there are other sources for this instruction set, but it will serve me later having written this out -- lending some muscle memory hopefully. We are interested in taking several OMC scans over the next couple weeks to estimate mode-matching of various cavities to the OMC in comparison to our models.
Going to sitemap > ASC > IFO Align Compact , you can find shortcuts for each of the suspensions. We will want to take both the ETMs to misaligned as well as the PRM and SRM. If we want to do a single bounce with ITMX, we misalign ITMY and vice-versa.
To misalign an optic from IFO Align Compact, click on the full optic suspension shortcut with the corresponding optic name (e.g. overlapping squares + "ETMX"). At the top of the suspension screen, take the guardian state to misaligned.
Going to sitemap > ASC > ASC Overview > DC Centering (middle screen), turn on the inputs to DC3 and DC4 pitch and yaw loops.
Make sure that the inputs to the centering loops start to go to zero and the outputs are not blowing up to infinity.
Then go to sitemap > OMC > OMC Overview > fast shutter and ensure that the status reads open, otherwise, hit open.
Going to sitemap > GRD > ISC Overview find the OMC guardian and take it to ASC_QPD_ON
Going to sitemap > OMC > OMC control, set the MASTER GAIN to 0.02 and bring the LSC offset to the far left ( -50.0 ).
Going out to the PSL racks, in the far right stack towards the bottom find the EOM drivers labeled 9MHz and 45MHz and flick the switch on the panel to OFF
Then below the RF Combiner Amplifier, unplug the cable going to the BNC port label 118 MHz.
An example can be found in my templates /ligo/home/matthewrichard.todd/Templates/omc/20251006_OMC_scan.xml
Open the template with DTT and save it as another copy, naming it with whatever date you are running it plus any notes.
[Note] This should be done at 10W nominally, so take the LASER_PWR guardian to POWER_10W before running the measurement (ensuring the IMC is locked).
This is an alog I started before the power outage, because we were worried that the filter cavity backscatter was the reason for our intermittent squeezer noise. (We now realize that the noise we are looking for is not from the filter cavity 87071.)
The overall message is that the filter cavity backscatter seems low compared to DARM, but there is a source of scattered light upstream of SFI2.
Filter cavity length
I've constructed a model of the filter cavity length loop using the foton filters for PRM in the CAL-CS model. As noted in 78728 we need to modify the analog gains for M3 for FC2. I've used a filter cavity pole of 34 Hz, and adjusted the sensor gain to get the model to match the measured open loop gain (plot). The measurement used in that plot has poor coherence below 5 Hz, which explains why the model doesn't seem to fit there. This model also matches the cross over measured by injected at M1 LOCK L well (plot).
The next plot shows the uncalibrated error signal (measured at LSC DOF2 IN1), with the loop correction applied (error_spectrum * (1-G)), and a line which I've added as a crude estimate of sensor noise. You can see that there seems to be a bump in sensor noise around 100 Hz that isn't included in my rough estimate, I am not sure what that is.
The next plot shows calibrated length noise.
Backscattered power
Using the measurement of excitations on ZM2 in 86778,we can estimate the amount of backscattered light that is reaching the filter cavity. The DCPD spectra, calibrated into RIN and with the DARM loop removed are plotted here and here with different FFT lengths. Next time if we do this measurement with a lower frequency and higher amplitude excitation we will be able to use a longer FFT length for the plot and still se
I've made a model of the noise caused by backscattered light using equation 4 (and 5) from P1200155. The excitation was a 1Hz 100 count excitation into test L, in the osems this showed a peak to peak amplitude of 0.37 um, and to go from optic motion to path length change we need roughly a factor of 4 since ZM2 is at a low angle of incidence and it is double passed. To match the shelf frequency in the measurement I had to increase the amplitude used in the model by a factor of 3.4. Using a QE of 100% gives a PD responsivity of 0.858 A/W, and 46.6mW of power on the OMC PDs. This model doesn't include any phase modulation from any other elements in the optical path, but the real measurement does, which is why the measurements shows a nice shelf but the model shows a series of peaks when I use a longer FFT. I think would be less apparent if we make the measurement with a lower frequency higher amplitude excitation next time.
The result of this shows that we have 12 pW of scattered light passing ZM2, since backscatter that reaches the filter cavity should all be reflected back towards the IFO along with the squeezing this means that we have 12 pW of scattered carrier from the OFI reaching the filter cavity. Comparing this to table 1 of T1800447 this is a lower scattered light power reaching the diodes than expected, for a similar level of carrier light reaching the DC PDs, which suggests that all three Faradays are providing the isolation level expected or slightly better. When driving ZM5, we get 12 nW of power scattered back to the interfometer, suggesting that there is a scattering source where we would not expect one to be. This seems most likely to be upstream of SFI2, since we only expect nW of total scattered light downstream of SFI2. If you are interested in looking at a diagram of possible scatters there is a VIP layout here, the beam which leaves B:M5 goes to a PD mounted on the ISI which is called B:PD1 and is intended to monitor light scattered from the OFI towards the squeezer.
Coupling and noise projection
The last two plots here show the results of a filter cavity noise injection, similar to what Naoki did in 78579. This suggests that this noise is large enough to include in our noise budget, but not nearly large enough to explain the excess noise we see in DARM when the filter cavity error signal is seeing extra noise.
The code and data to produce this are in sheila.dwyer/SQZ/FilterCavity/fc_lsc_model.py
I posted this as a comment on the wrong alog on Friday, adding it here now. Also see follow up measurements with changes to SFI2 temperature, and the comparison measurement from LLO 87309
Power level heading towards HAM7 from OFI:
The power on the DCPDs is 47mW, and there is 12pW retro-reflected off the filter cavity, so the total isolation provided by OFI + SFI2 + SFI1 is 2.5e-10 in power ratio, or 96dB. The OFI isolation ratio was measured to be 43dB in 79379. If this is true it would imply that one of the SFIs is providing less than the 30dB isolation assumed in T1800447, and we should have 2uW of carrier light headed towards SFI2.
Our readback of the 1% pick off of light from the interferometer heading towards SFI2, B:PD1 (OFI PD A) says that we have 0.03mW on it, meaning 3mW from the IFO going towards SFI2, about 1mW of this would be carrier based on (87114),which seems too high.
The responsivity of this PD was checked in 60284, and later double checked because it seemed low (the settings are still the same). The similar PD OFI PDB has a measured responsivity of 0.25A/W and the excelitas website lists a peak responsivity of 0.6A/W at 850nm for these PDs. (ffd-200h-si-pin) If we think that this calibration was mistaken and the real responsivity is more like OFI PD B, 0.25A/W, there is 0.72 mW of light from the OFI heading towards SFI2, ~240 uW of carrier, the OFI isolation would only be 23dB, and the SFIs must be providing something like 36 dB each.
Reflectivity:
If my interpretation of the fringe wrapping measurements into power are correct (12 nW of power is retroreflected from the path that includes ZM5), we are reflecting 50ppm of the carrier scattered toward HAM7 using the (recalibrated) 240uW value from OFI PDB, or 0.6% if we believe the isolation ratio measurement for the OFI and use the 2uW value. B:BS1 is a 1%, so the maximum reflectivitiy we could get from scatter in the B:PD1 path would be 0.01%. This means that the B:PD1 path can't explain the reflectivity needed if there is 2uW headed towards HAM7, and even if there is 240uW heading towards HAM7 this PD seems unlikely to explain the scatter, since it would need to reflect half the light that's incident on the PD. Camilla did alog the check of the alignment (and the beam dump catching the retro-reflection off this diode: 65006)
Daniel looked at some of the excelitas website catalog and he thinks that our measurement of 0.06A/W could be a reasonable responsivity for the OFI PD A. LLO's responsivity for this PD is set to 0.065A/W.
This morning we opened the squeezer beam divererter while Matt was doing single bounce OMC scans, (87342) when there was 9.25W incident on PRM.
9.25W on PRM * 0.0299 PRM transmission * 0.25 (2 BS passes) * 0.03234 = 22.4mW expected arriving at OFI. AS_C_NSUM is calibrated into Watts arriving at HAM6, which says 22.9mW for this time.
OFI PD A reports a 1.1uW increase in measured power when the beam diverter opens (first attachment), meaning that there is about 100uW from the OFI sent to HAM7 in single bounce, or 0.4% of the light arriving at the OFI is sent to HAM7 according to this PD, or 23dB of isolation for this port. The 43dB measurement I referenced above is isolation for HAM6 scatter, and it doesn't apply to the light sent to HAM7.
So, this suggests that perhaps we can trust this OFI PD readback, and perhaps there is about 1mW of carrier sent to HAM7 when we are in full lock. This means that we need a reflectivity of 10ppm to explain our fringe wrapping measurement; if the scattering happens behind the 1% beam splitter it should have a reflectivity of 10% to explain what we see.
LLO has 50mA on the OMC PDs, compared to 40mA here, their OFI PD A reports 0.01mW power in full lock, 3 times less than what we see here.
Firstly I am very sorry for the length of this alog
I needed to finish up the comparisons for the satamps that were swapped on Tuesday (86207), as well as rerun almost all of the other comparison damp regression plots for every suspension that has had its satamp swapped out for ECR E2400330, either with different times or with the loop suppression divided out. There were also multiple changes made to the damp_regression_compare.m file. So I've gone and done that, so here are the results in this master post. I will link to the old results when applicable. They are out of order as compared to when their satamps were swapped.
damp_regression_compare.m
Now creates a plot of the ratios, lists important IFO info, and saves some of the variables to a .mat file
found in /ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/damp_regression_compare.m
newest version is r12583
Input
IM1
Results:
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM1/SAGM1/Results/allDampRegressCompare_H1SUSIM1_M1_NoiseComparison_1437330256vs1438626136-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM1/SAGM1/Results/allDampRegressCompare_H1SUSIM1_M1_1437330256vs1438626136-1200.mat
Data:
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM1/SAGM1/Data/dampRegress_H1SUSIM1_M1_1437330256_1200.mat
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM1/SAGM1/Data/dampRegress_H1SUSIM1_M1_1438626136_1200.mat
r12561
IM2
Results:
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM2/SAGM1/Results/allDampRegressCompare_H1SUSIM2_M1_NoiseComparison_1437330256vs1438626136-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM2/SAGM1/Results/allDampRegressCompare_H1SUSIM2_M1_1437330256vs1438626136-1200.mat
Data:
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM2/SAGM1/Data/dampRegress_H1SUSIM2_M1_1437330256_1200.mat
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM2/SAGM1/Data/dampRegress_H1SUSIM2_M1_1438626136_1200.mat
r12562
IM3
Results:
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM3/SAGM1/Results/allDampRegressCompare_H1SUSIM3_M1_NoiseComparison_1437330256vs1438626136-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM3/SAGM1/Results/allDampRegressCompare_H1SUSIM3_M1_1437330256vs1438626136-1200.mat
Data:
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM3/SAGM1/Data/dampRegress_H1SUSIM3_M1_1437330256_1200.mat
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM3/SAGM1/Data/dampRegress_H1SUSIM3_M1_1438626136_1200.mat
r12563
IM4
Results:
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM4/SAGM1/Results/allDampRegressCompare_H1SUSIM4_M1_NoiseComparison_1437330256vs1438626136-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM4/SAGM1/Results/allDampRegressCompare_H1SUSIM4_M1_1437330256vs1438626136-1200.mat
Data:
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM4/SAGM1/Data/dampRegress_H1SUSIM4_M1_1437330256_1200.mat
/ligo/svncommon/SusSVN/sus/trunk/HAUX/H1/IM4/SAGM1/Data/dampRegress_H1SUSIM4_M1_1438626136_1200.mat
r12560
MC1(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/MC1/Results/allDampRegressCompare_H1SUSMC1_M1_NoiseComparison_1437192600vs1437240215-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/MC1/Results/allDampRegressCompare_H1SUSMC1_M1_1437192600vs1437240215-1200.mat
r12557
MC2(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/MC2/SAGM1/Results/allDampRegressCompare_H1SUSMC2_M1_NoiseComparison_1436631330vs1438441235-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/MC2/SAGM1/SAGM1/Results/allDampRegressCompare_H1SUSMC2_M1_1436631330vs1438441235-1200.mat
Data:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/MC2/SAGM1/Data/dampRegress_H1SUSMC2_M1_1438441235_1200.mat
r12554
MC3(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/MC3/Results/allDampRegressCompare_H1SUSMC3_M1_NoiseComparison_1437115850vs1437282002-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/MC3/Results/allDampRegressCompare_H1SUSMC3_M1_1437115850vs1437282002-1200.mat
r12558
PRM(original results)(added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PRM/SAGM1/Results/allDampRegressCompare_H1SUSPRM_M1_NoiseComparison_1435154988vs1435435046-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PRM/SAGM1/Results/allDampRegressCompare_H1SUSPRM_M1_1435154988vs1435435046-1200.mat
r12559
PR2(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PR2/Results/allDampRegressCompare_H1SUSPR2_M1_NoiseComparison_1435154988vs1436654703-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PR2/Results/allDampRegressCompare_H1SUSPR2_M1_1435154988vs1436654703-1200.mat
r12556
PR3(original results)
Results:
/ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/PR3/SAGM1/Results/allDampRegressCompare_H1SUSPR3_M1_NoiseCompare_H1SUSPR3_M1_NoiseComparison_1435348334vs1435435046-1200.pdf
r12533
/ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/PR3/SAGM1/Results/allDampRegressCompare_H1SUSPR3_M1_1435348334vs1435435046-1200.mat
r12565
BS(original results)(added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/BSFM/H1/BS/SAGM1/Results/allDampRegressCompare_H1SUSBS_M1_NoiseComparison_1435062667vs1435435038-1200.pdf
r12535
/ligo/svncommon/SusSVN/sus/trunk/BSFM/H1/BS/SAGM1/Results/allDampRegressCompare_H1SUSBS_M1_1435062667vs1435435038-1200.mat
r12567
Data (new before time):
/ligo/svncommon/SusSVN/sus/trunk/BSFM/H1/BS/SAGM1/Data/dampRegress_H1SUSBS_M1_1435062667_1200.mat
r12535
Output
SRM(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SRM/SAGM1/Results/allDampRegressCompare_H1SUSSRM_M1_NoiseComparison_1435154988vs1435435046-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SRM/SAGM1/Results/allDampRegressCompare_H1SUSSRM_M1_1435154988vs1435435046-1200.mat
r12568
SR2(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM1/Results/allDampRegressCompare_H1SUSSR2_M1_NoiseComparison_1435482383vs1436080373-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM1/Results/allDampRegressCompare_H1SUSSR2_M1_1435482383vs1436080373-1200.mat
r12569
SR3(original results)
Results:
/ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/SR3/SAGM1/Results/allDampRegressCompare_H1SUSSR3_M1_NoiseComparison_1435348334vs1435435046-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/SR3/SAGM1/Results/allDampRegressCompare_H1SUSSR3_M1_1435348334vs1435435046-1200.mat
r12570
OMC
Results:
/ligo/svncommon/SusSVN/sus/trunk/OMCS/H1/OMC/SAGM1/Results/allDampRegressCompare_H1SUSOMC_M1_NoiseComparison_1437330259vs1438454240-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/OMCS/H1/OMC/SAGM1/Results/allDampRegressCompare_H1SUSOMC_M1_1437330259vs1438454240-1200.mat
Data:
/ligo/svncommon/SusSVN/sus/trunk/OMCS/H1/OMC/SAGM1/Data/dampRegress_H1SUSOMC_M1_1438454240_1200.mat
/ligo/svncommon/SusSVN/sus/trunk/OMCS/H1/OMC/SAGM1/Data/dampRegress_H1SUSOMC_M1_1437330259_1200.mat
r12582
SQZ
FC1
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/FC1/SAGM1/Results/allDampRegressCompare_H1SUSFC1_M1_NoiseComparison_1437766177vs1438449277-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/FC1/SAGM1/Results/allDampRegressCompare_H1SUSFC1_M1_1437766177vs1438449277-1200.mat
Data:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/FC1/SAGM1/Data/dampRegress_H1SUSFC1_M1_1437766177_1200.mat
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/FC1/SAGM1/Data/dampRegress_H1SUSFC1_M1_1438449277_1200.mat
r12572
FC2
Results:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/FC2/SAGM1/Results/allDampRegressCompare_H1SUSFC2_M1_NoiseComparison_1437766177vs1438449277-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/FC2/SAGM1/Results/allDampRegressCompare_H1SUSFC2_M1_1437766177vs1438449277-1200.mat
Data:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/FC2/SAGM1/Data/dampRegress_H1SUSFC2_M1_1437766177_1200.mat
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/FC2/SAGM1/Data/dampRegress_H1SUSFC2_M1_1438449277_1200.mat
r12573
ITMs
ITMX M0(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGM0/Results/allDampRegressCompare_H1SUSITMX_M0_NoiseComparison_1435482383vs1436080373-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGM0/Results/allDampRegressCompare_H1SUSITMX_M0_1435482383vs1436080373-1200.mat
r12574
ITMX R0(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGR0/Results/allDampRegressCompare_H1SUSITMX_R0_NoiseComparison_1435482383vs1436080373-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGR0/Results/allDampRegressCompare_H1SUSITMX_R0_1435482383vs1436080373-1200.mat
r12575
ITMY M0(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGM0/Results/allDampRegressCompare_H1SUSITMY_M0_NoiseComparison_1435482383vs1436080373-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGM0/Results/allDampRegressCompare_H1SUSITMY_M0_1435482383vs1436080373-1200.mat
r12576
ITMY R0(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGR0/Results/allDampRegressCompare_H1SUSITMY_R0_NoiseComparison_1435482383vs1436080373-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGR0/Results/allDampRegressCompare_H1SUSITMY_R0_1435482383vs1436080373-1200.mat
r12577
ETMs
ETMX M0(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGM0/Results/allDampRegressCompare_H1SUSETMX_M0_NoiseComparison_1435060998vs1436769334-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGM0/Results/allDampRegressCompare_H1SUSETMX_M0_1435060998vs1436769334-1200.mat
r12578
ETMX R0(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGR0/Results/allDampRegressCompare_H1SUSETMX_R0_NoiseComparison_1435060998vs1436769334-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGR0/Results/allDampRegressCompare_H1SUSETMX_R0_1435060998vs1436769334-1200.mat
r12578
ETMX L1(original results)
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGL1/Results/allDampRegressCompare_H1SUSETMX_L1_NoiseComparison_1435060998vs1436769334-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGL1/Results/allDampRegressCompare_H1SUSETMX_L1_1435060998vs1436769334-1200.mat
r12579
ETMY M0(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMY/SAGM0/Results/allDampRegressCompare_H1SUSETMY_M0_NoiseComparison_1436521059vs1438453617-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMY/SAGM0/Results/allDampRegressCompare_H1SUSETMY_M0_1436521059vs1438453617-1200.mat
r12580
Data (new after time):
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMY/SAGM0/Data/dampRegress_H1SUSETMY_M0_1438453617_1200.mat
r12548
ETMY R0(original results) (added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMY/SAGR0/Results/allDampRegressCompare_H1SUSETMY_R0_NoiseComparison_1436521059vs1438453617-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMY/SAGR0/Results/allDampRegressCompare_H1SUSETMY_R0_1436521059vs1438453617-1200.mat
r12580
Data (new before and after time):
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMY/SAGR0/Data/dampRegress_H1SUSETMY_R0_1436521059_1200.mat
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMY/SAGR0/Data/dampRegress_H1SUSETMY_R0_1438453617_1200.mat
r12550
TMSs
TMSX(original results)(added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/TMTS/H1/TMSX/SAGM1/Results/allDampRegressCompare_H1SUSTMSX_M1_NoiseComparison_1435150628vs1437199319-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/TMTS/H1/TMSX/SAGM1/Results/allDampRegressCompare_H1SUSTMSX_M1_1435150628vs1437199319-1200.mat
r12553
TMSY(original results)(added loop suppression)
Results:
/ligo/svncommon/SusSVN/sus/trunk/TMTS/H1/TMSY/SAGM1/Results/allDampRegressCompare_H1SUSTMSY_M1_NoiseComparison_1437213557vs1437257352-1200.pdf
/ligo/svncommon/SusSVN/sus/trunk/TMTS/H1/TMSY/SAGM1/Results/allDampRegressCompare_H1SUSTMSY_M1_1437213557vs1437257352-1200.mat
r12581
More satamp comparison plots here: 87351
For PRM (M2, M3), SRM (M2, M3), BS (M2), ITMX (L1), ITMY (L1), ETMY (L1), SR2 (M2, M3), PR2 (M2, M3)