Today, Sheila and I decided to increase the ETMX ESD bias voltage. We would like to operate at a higher bias for a short period to see if the extra actuation range allows us to survive the ETMX glitch locklosses. However, we also wanted to understand what effect this has on our range.
Sheila made small steps to increase the ETMX bias voltage and adjusted the L3 drivealign gain accordingly. After every step, I measured the DARM open loop gain and we adjusted the drivealign gain further to maintain the DARM UGF. Once we doubled the voltage, we further adjusted the drivealign gain to bring kappa TST to one. It's important to note that we saw that the correction factor required to maintain the UGF (at 70 Hz) was slightly different than the correction factor required to bring kappa TST back to 1 (measured at 17.6 Hz).
We took a PCAL broadband measurement at the regular and double bias configurations (documented here). Even with kappa TST near 1, there was a small frequency-dependent difference between the two measurements.
Sheila then took us back and forth from the double bias to regular bias states so we could get some noise comparison times to determine if the noise is worse with double bias.
Times in UTC | Start | End |
double bias | 17:41:58 | 18:03:37 |
single bias | 18:08:20 | 18:17:30 |
double bias | 18:18:37 | 18:26:37 |
single bias | 18:27:40 | 18:35:40 |
I exported the PCAL broadband injections and used them to calibration GDS strain for the four times above into PCAL meters. The noise from 15-400 Hz looks to be the same for each time, so I don't think there will be a significant impact to the sensitivity if we double the bias.
I ran a linear regression fit on the voltage and drivealign data from our steps, using this document as reference. I was able to fit alpha - gamma (slope) and the beta values (y-intercept). I calculate alpha - gamma = 9.14e-10 N/V^2 and beta - beta2 = -4.08e-8 N/V
We are planning to go to this double bias for some time to see if reduces the number of ETMX glitch locklosses.
We've done this change with a guardian shell. I've attached a text file with options that people can use to do these steps, or revert them.
Lockloss at the end of comissioning - looks like an ETM glitch.
Unknown cause lockloss that happened early in comissioning while ramping bias gains, but we are unsure if this is the cause of the Lockloss.
Summary: We can use single bounce scans in the OMC to constrain how the signal recycling cavity mode-matching affects mode-matching to the OMC - still a work in progress.
This is a collection of the single bounce scans we have done with the OMC in O4b and O4c (excluding some we did between April and July after the first OFI damage which might have made this meaasurement give some weird results) :
SR3 | OM2 | ITMX | ITMY | Alog | Mode-mis-match [%] |
---|---|---|---|---|---|
Cold | Cold | Mis-aligned | Aligned | 79229 | 9.83 |
Cold | Hot | Mis-aligned | Aligned | 78727 | 6.62 |
Hot | Cold | Aligned | Mis-aligned | 85693 | 9.63 |
Hot | Cold | Mis-aligned | Aligned | 85693 | 7.06 |
Hot | Hot | Aligned | Mis-aligned | 85698 | 5.1 |
Hot | Hot | Mis-aligned | Aligned | 85698 | 3.08 |
For the single bounce measurements we orginally thought that which ITM the beam bounced off did not affect the mode-matching, but this looks not to be the case so in the following analysis I will only compare measurements where we had ITMX mis-aligned and the beam bouncing off ITMY.
I already used the measurements from the first two rows to estimate the beam parameter just before OM2 in the single bounce configuration in alog #84255.
Since we had the SR3 heater on in the bottom four measurements mentioned above this gives us some points to constrain the mode-matching of the input beam to the signal recycling cavity as well as to the OMC.
The q parameter can be used to define the electric field amplitude transverse to the beam propagation direction z:
U = 1/q ( exp( -jk ( x2 + y2 ) / 2q ))
where k is the wavenumber of the light and x and y are the transverse distances from the center of the beam in the horizontal and vertical directions.
Using the overlap integral:
O(q1,q2) = | U2 U1* |2 / ( |U1|2 |U1|2 )
where U1 is the field amplitude for TM 00 mode of the OMC and U2 is the field amplitude of the mode you are trying to work out the mode-matching to.
One can then define a mode mis-match between the modes U1 U2 :
MM % = (1 - O(q1,q2)) * 100,
In the previous alog I took a grid of possible q-parameters just before OM2 and plotted a contour on this grid showing which of the q values are compatible with the mode-matching I measured for hot OM2 and cold OM2.
Since I have two measurement showing SR3 hot with OM2 both cold and hot I will plot these two countours on the same plot.
The two possible qs this gives us are the overlap of the green and magenta lines - ie. the q parameter could be either of these values when SR3 is hot.
q1 = 0.748 + 0.967i
q2 = 1.44 + 1.01i
FAMIS 31096
No major changes this week, but the FSS RefCav trans TPD jumps I first noticed last week are still happening, so I continued my investigation into their cause.
Thinking these jumps were being caused by some frequency feedback from the IMC or the arms since they don't seem to line up with anything else in the PSL, I trended some IMC signals looking for similar behavior. Sure enough, several IMC electronics signals have trends that follow the jumps in power seen on the FSS TPD, including IMC-F. See final screenshot for a before/after comparison of these signals around last Tuesday's maintenance period when this change began. Also, in looking at more locking examples, I can say that the jumps start occurring towards the end of 'LOCKING_ALS' or during 'FIND_IR' states in main locking and persist until the next lockloss. Again, not sure that anything really needs to be done about this as it hasn't been causing problems that we've noticed so far, but it would be interesting to know why this change started and if it goes away for some reason, so I'll continue to keep an eye on it.
Took a calibration measurement as the first thing for comissioning this morning (since we missed our window over the weekend)
BB Start: 1437750930
BB End: 1437751248
Calibration Monitor Attached
notification: end of measurement
notification: end of test
diag> save /ligo/groups/cal/H1/measurements/PCALY2DARM_BB/PCALY2DARM_BB_20250728T151520Z.xml
/ligo/groups/cal/H1/measurements/PCALY2DARM_BB/PCALY2DARM_BB_20250728T151520Z.xml saved
diag> quit
EXIT KERNEL
2025-07-28 08:20:30,384 bb measurement complete.
2025-07-28 08:20:30,384 bb output: /ligo/groups/cal/H1/measurements/PCALY2DARM_BB/PCALY2DARM_BB_20250728T151520Z.xml
2025-07-28 08:20:30,384 all measurements complete.
This compares the broadband from last Thursday (blue reference) to today (red live).
Broadband Re-run (Part of comissioning)
Start: 1437759350
End: 1437759670
notification: end of measurement
notification: end of test
diag> save /ligo/groups/cal/H1/measurements/PCALY2DARM_BB/PCALY2DARM_BB_20250728T173540Z.xml
/ligo/groups/cal/H1/measurements/PCALY2DARM_BB/PCALY2DARM_BB_20250728T173540Z.xml saved
diag> quit
EXIT KERNEL
2025-07-28 10:40:51,396 bb measurement complete.
2025-07-28 10:40:51,396 bb output: /ligo/groups/cal/H1/measurements/PCALY2DARM_BB/PCALY2DARM_BB_20250728T173540Z.xml
2025-07-28 10:40:51,397 all measurements complete.
The second measurement Ibrahim has posted here was performed when we were at double ESD bias. We corrected the ETMX drivealign L2L gain so that kappa TST would be 1. Even with this adjustment, there appears to be some frequency dependent difference between the measurements.
Using my model for the propagation from OM2 to the OMC I discussed in alog #84255, I made a contour plot for the mode overlap (O(q1,q2 ))c between the mode propagated through cold OM2 to the OMC, q1 and the fundamental mode of the OMC, q2 divided by the mode propagated through hot OM2 overlapped with the OMC mode, (O(q1,q2 ))h .
This is so I could comnpare it to measurements I made of the drop in optical gain, G when the curvature of OM2 was changed. Its hard to predict how much loss in total there is with the full interferomter locked but the optical gain change can tell us the change in optical loss between these two states which we assume to be due to mode-mis-match.
O' / O = (G' / G)2
In the plot I have used overlap ratio percentage, O % on the z axis, the real part of of the q I started with between OM1 and OM2 on the x-axis, and the imaginary part of this q on the y-axis.
O % = (O(q1,q2 ))h / (O(q1,q2 ))c × 100
The white line gives the square ratio of the optical gains measured in full-lock (alog #82559) for each of these states. The code to run this is in OM2_to_OMC_comp_full_IFO.m found at this respository on ligo gitlab.
The white line contains a contour of possible values of the q parameter between OM1 and OM2 for the full-locked state of the interferometer bar any changes since the end of January 2025 when I took these measurements.
The limit on mode-matching to the OMC with OM2 hot is 96.2% of the mode-matching to the OMC with OM2 cold. This means in full-lock our mode-matching should be better with a cold OM2.
The q value before OM2 should lie somewhere on this white curve in full-lock but we don't have any direct mode measurements with the interferometer in full-lock to constrain this yet.
WP 12696
ECR E2400330
Drawing D0901284-v5
Modified List T2500232
The following SUS SAT Amps were upgraded per ECR E2400330. Modification improves the whitening stage to reduce ADC noise from 0.05 to 10 Hz. The EY PUM and UIM SAT Amps were NOT upgraded.
Suspension | Old | New | OSEM |
ETMY MO | S1100098 | S1100088 | F1F2F3SD |
ETMY MO/RO | S1100079 | S1100083 | RTLF/RTLF |
ETMY RO | S1100087 | S1000281 | F1F2F3SD |
TMSY | S1100172 | S1100148 | F1F2F3LF |
TMSY | S1100107 | S1100172 | RTSD |
MC1 | S1100128 | S1100118 | T1T2T3LF |
MC1/MC3 | S1000292 | S1000287 | RTSD/T1T2 |
MC3 | S1000297 | S1100119 | T3LFRTSD |
F. Clara, J. Kissel, O. Patane, M. Pirello
Once the new satamps were installed, I ran the script satampswap_bestpossible_filterupdate_ECR_E2400330.py to update the compensation filters for these suspensions. These 'best possible' compensation gains come from the tests Jeff did on each satamp before installation, which are found in /ligo/svncommon/SusSVN/sus/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Results/.
My input and the corresponding output is below:
oli.patane@cdsws27:/ligo/svncommon/SusSVN/sus/trunk/Common/PythonTools$ py satampswap_bestpossible_filterupdate_ECR_E2400330.py -o TMSY ETMY_M0_R0
All updated filters grabbed for TMSY
TMSY M1 F1 compensation filter updated to zpk([5.3],[0.0969],1,"n")
TMSY M1 F2 compensation filter updated to zpk([5.28],[0.0964],1,"n")
TMSY M1 F3 compensation filter updated to zpk([5.2],[0.095],1,"n")
TMSY M1 LF compensation filter updated to zpk([5.26],[0.096],1,"n")
TMSY M1 RT compensation filter updated to zpk([5.17],[0.0945],1,"n")
TMSY M1 SD compensation filter updated to zpk([5.26],[0.0961],1,"n")
write /opt/rtcds/userapps/release/sus/h1/filterfiles/H1SUSTMSY.txt
Done writing updated filters for TMSY
All updated filters grabbed for ETMY
ETMY R0 F1 compensation filter updated to zpk([5.2],[0.0951],1,"n")
ETMY R0 F2 compensation filter updated to zpk([5.2],[0.0951],1,"n")
ETMY R0 F3 compensation filter updated to zpk([5.25],[0.0959],1,"n")
ETMY R0 SD compensation filter updated to zpk([5.35],[0.098],1,"n")
ETMY M0 F1 compensation filter updated to zpk([5.31],[0.0971],1,"n")
ETMY M0 F2 compensation filter updated to zpk([5.27],[0.0965],1,"n")
ETMY M0 F3 compensation filter updated to zpk([5.22],[0.0955],1,"n")
ETMY M0 SD compensation filter updated to zpk([5.17],[0.0946],1,"n")
ETMY M0 LF compensation filter updated to zpk([5.2],[0.0951],1,"n")
ETMY M0 RT compensation filter updated to zpk([5.28],[0.0965],1,"n")
ETMY R0 LF compensation filter updated to zpk([5.29],[0.0967],1,"n")
ETMY R0 RT compensation filter updated to zpk([5.26],[0.0962],1,"n")
write /opt/rtcds/userapps/release/sus/h1/filterfiles/H1SUSETMY.txt
Done writing updated filters for ETMY
All done! Remember to double check and load in the filters for ['TMSY', 'ETMY_M0_R0']
oli.patane@cdsws27:/ligo/svncommon/SusSVN/sus/trunk/Common/PythonTools$ py satampswap_bestpossible_filterupdate_ECR_E2400330.py -o MC1 MC3
All updated filters grabbed for MC1
MC1 M1 RT compensation filter updated to zpk([5.13],[0.0937],1,"n")
MC1 M1 SD compensation filter updated to zpk([5.25],[0.096],1,"n")
MC1 M1 T1 compensation filter updated to zpk([5.26],[0.0962],1,"n")
MC1 M1 T2 compensation filter updated to zpk([5.18],[0.0947],1,"n")
MC1 M1 T3 compensation filter updated to zpk([5.32],[0.0972],1,"n")
MC1 M1 LF compensation filter updated to zpk([5.12],[0.0938],1,"n")
write /opt/rtcds/userapps/release/sus/h1/filterfiles/H1SUSMC1.txt
Done writing updated filters for MC1
All updated filters grabbed for MC3
MC3 M1 T3 compensation filter updated to zpk([5.32],[0.0972],1,"n")
MC3 M1 LF compensation filter updated to zpk([5.19],[0.0949],1,"n")
MC3 M1 RT compensation filter updated to zpk([5.35],[0.0979],1,"n")
MC3 M1 SD compensation filter updated to zpk([5.19],[0.0949],1,"n")
MC3 M1 T1 compensation filter updated to zpk([5.31],[0.097],1,"n")
MC3 M1 T2 compensation filter updated to zpk([5.24],[0.0958],1,"n")
write /opt/rtcds/userapps/release/sus/h1/filterfiles/H1SUSMC3.txt
Done writing updated filters for MC3
All done! Remember to double check and load in the filters for ['MC1', 'MC3']
After this I loaded in these new filters.
The serial numbers in Fil's and OLD and NEW columns are flip flopped in the main aLOG, LHO:85922. Here's the corrected version with the serial number's columns flipped to reflect reality. Suspension Old New OSEM ETMY MO S1100088 S1100098 F1F2F3SD ETMY MO/RO S1100083 S1100079 RTLF/RTLF ETMY RO S1000281 S1100087 F1F2F3SD TMSY S1100148 S1100172 F1F2F3LF TMSY S1100172 S1100107 RTSD MC1 S1100118 S1100128 T1T2T3LF MC1/MC3 S1000287 S1000292 RTSD/T1T2 MC3 S1100119 S1000297 T3LFRTSD
Here's the characterization data and fit results for S1100098 , assigned to ETMY M0's F1F2F3SD OSEMs (Fil refers to this as ETMY MO F1F2F3SD above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100098_ETMY_M0_F1F2F3SD_20250717.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design ETMY M0 S1100098 CH1 F1 0.0971:5.31 120 zpk([5.31],[0.0971],1,"n") CH2 F2 0.0965:5.27 120 zpk([5.27],[0.0965],1,"n") CH3 F3 0.0955:5.22 120 zpk([5.22],[0.0955],1,"n") CH4 SD 0.0946:5.17 120 zpk([5.17],[0.0946],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm, as it's not used in the compensation filter -- but also because the magnitude of the measurements didn't need me to adjust them; I was able to get a good phase and magnitude fit by just adjusting the zero frequency.
Here's the characterization data and fit results for S1100079 , assigned to ETMY M0/R0's LFRT/LFRT OSEMs (Fil refers to this as ETMY MO/RO RTLF/RTLF above -- note his typo in channel order). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100079_ETMY_M0R0_LFRTLFRT_20250717.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design ETMY M0 S1100079 CH1 LF 0.0951:5.20 120 zpk([5.20],[0.0951],1,"n") M0 CH2 RT 0.0965:5.28 120 zpk([5.28],[0.0965],1,"n") R0 CH3 LF 0.0967:5.29 120 zpk([5.29],[0.0967],1,"n") R0 CH4 RT 0.0962:5.26 120 zpk([5.26],[0.0962],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm, as it's not used in the compensation filter -- but also because the magnitude of the measurements didn't need me to adjust them; I was able to get a good phase and magnitude fit by just adjusting the zero frequency.
Here's the characterization data and fit results for S1100087 , assigned to ETMY R0's F1F2F3SD OSEMs (Fil refers to this as ETMY RO F1F2F3SD above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100087_ETMY_R0_F1F2F3SD_20250717.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design ETMY R0 S1100087 CH1 F1 0.0951:5.20 120 zpk([5.20],[0.0951],1,"n") CH2 F2 0.0951:5.20 120 zpk([5.20],[0.0951],1,"n") CH3 F3 0.0959:5.25 120 zpk([5.25],[0.0959],1,"n") CH4 SD 0.0980:5.35 120 zpk([5.35],[0.0980],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm, as it's not used in the compensation filter -- but also because the magnitude of the measurements didn't need me to adjust them; I was able to get a good phase and magnitude fit by just adjusting the zero frequency.
Here's the characterization data and fit results for S1100172 , assigned to TMSY M1's F1F2F3LF OSEMs (Fil refers to this as TMSY F1F2F3LF above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100172_TMSY_M1_F1F2F3LF_20250717.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design TMSY M1 S1100172 CH1 F1 0.0969:5.30 120 zpk([5.30],[0.0969],1,"n") CH2 F2 0.0964:5.28 120 zpk([5.28],[0.0964],1,"n") CH3 F3 0.0950:5.20 120 zpk([5.20],[0.0950],1,"n") CH4 LF 0.0960:5.26 120 zpk([5.26],[0.0960],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm.
Here's the characterization data and fit results for S1100107 , assigned to TMSY M1's RTSDxxxx OSEMs (Fil refers to this as TMSY RTSD above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100107_TMSY_M1_RTSDxxxx_20250717.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design TMSY M1 S1100107 CH1 RT 0.0945:5.17 120 zpk([5.17],[0.0945],1,"n") CH2 SD 0.0961:5.26 120 zpk([5.26],[0.0961],1,"n") CH3 xx 0.0956:5.23 120 zpk([5.23],[0.0956],1,"n") CH4 xx 0.0957:5.24 120 zpk([5.24],[0.0957],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm.
Here's the characterization data and fit results for S1100128 , assigned to MC1 M1's T1T2T3LF OSEMs (Fil refers to this as MC1 T1T2T3LF above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100128_MC1_M1_T1T2T3LF_20250717.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design MC1 M1 S1100128 CH1 T1 0.0962:5.26 120 zpk([5.26],[0.0962],1,"n") CH2 T2 0.0947:5.18 120 zpk([5.18],[0.0947],1,"n") CH3 T3 0.0972:5.32 120 zpk([5.32],[0.0972],1,"n") CH4 LF 0.0938:5.12 120 zpk([5.12],[0.0938],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm.
Here's the characterization data and fit results for S1000292 , assigned to MC1/MC3 M1's RTSD/T1T2 OSEMs (Fil refers to this as MC1/MC3 RTSD/T1T2 above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1000292_MC1MC3_M1_RTSDT1T2_20250717.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are MC1 M1 S1000292 CH1 RT 0.0937:5.13 120 zpk([5.13],[0.0937],1,"n") MC1 M1 CH2 SD 0.0960:5.25 120 zpk([5.25],[0.0960],1,"n") MC3 M1 CH3 T1 0.0970:5.31 120 zpk([5.31],[0.0970],1,"n") MC3 M1 CH4 T2 0.0958:5.24 120 zpk([5.24],[0.0958],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm.
Here's the characterization data and fit results for S1000297 , assigned to MC3 M1's T3LFRTSD OSEMs (Fil refers to this as MC3 T3LFRTSD above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1000297_MC3_M1_T3LFRTSD_20250721.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are MC3 M1 S1000297 CH1 T3 0.0972:5.32 120 zpk([5.32],[0.0972],1,"n") CH2 LF 0.0949:5.19 120 zpk([5.19],[0.0949],1,"n") CH3 RT 0.0979:5.35 120 zpk([5.35],[0.0979],1,"n") CH4 SD 0.0949:5.19 120 zpk([5.19],[0.0949],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm.
Ivey used the ISO calibration measurements that I took earlier (85906) to calculate what the OSEMINF gains should be on SR3 (85907), and this script also calculates what it thinks the compensation gain in the DAMP filter bank should be.
The next step is to use OLG TFs to measure what values we would use in the DAMP filter bank to compensate for the change in OSEMINF gains, and we can compare them to the calculated values to see how close they are.
I took two sets of OLG measurements for SR3:
- a set with the nominal OSEMINF gains
T1: 1.478
T2: 0.942
T3: 0.952
LF: 1.302
RT: 1.087
SD: 1.290
- a set with the OSEMINF gains changed to the values in 85907
T1: 3.213
T2: 1.517
T3: 1.494
LF: 1.733
RT: 1.494
SD: 1.793
Measurement settings:
- SR3 in HEALTH_CHECK but with damping loops on
- SR3 damping nominal (all -0.5)
- HAM5 in ISOLATED
Nominal gain set:
/ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/SR3/SAGM1/Data/2025-07-22_1700_H1SUSSR3_M1_WhiteNoise_{L,T,V,R,P,Y}_0p02to50Hz_OpenLoopGainTF.xml r12478
New gain set:
/ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/SR3/SAGM1/Data/2025-07-22_1800_H1SUSSR3_M1_WhiteNoise_{L,T,V,R,P,Y}_0p02to50Hz_OpenLoopGainTF.xml r12478
Once I had taken these measurements, I exported txt files for each dof's OLG and used one of my scripts, /ligo/svncommon/SusSVN/sus/trunk/HLTS/Common/MatlabTools/divide_traces_tfs.m to plot the OLG for each dof to compare the traces between OSEMINF gain differences and then divide the traces and grab an average of that, which will be the compensation gain put in as a filter in the DAMP filter bank (plots). The values I got for the compensation gains are below:
L: 0.740
T: 0.732
V: 0.548
R: 0.550
P: 0.628
Y: 0.757
DOF | OLTF measured and calculated DAMP Compensation gains | ISO Calibration measurement calculated compensation gains (85907) | Percent difference (%) |
L | 0.740 | 0.740 | 0.0 |
T | 0.732 | 0.719 | 1.8 |
V | 0.548 | 0.545 | 0.5 |
R | 0.550 | 0.545 | 0.9 |
P | 0.628 | 0.629 | 0.2 |
Y | 0.757 | 0.740 | 2.3 |
These are pretty similar to what my script had found them to be last time before the satamp swap (85288), as well as being very similar to the values that Ivey's script had calculated.
Maybe the accuracy from Ivey's script means that in the future we don't need to run the double sets of OLG transfer functions and can jsut use the values that the script gives.
The compensation gains have been loaded into the SR3 DAMP filter bank in FM7 as well as being updated in the estimator damp banks for P and Y. They have been loaded in but of course, are currrently left off for nominal operations since the OSEMINF gains haven't been updated yet
The OSEMINF gains and these new DAMP compensating gains have been turned on together: 86070
WP 12675
WP 12676
ECR E2400330
Drawing D0901284-v5
Modified List T2500232
The following SUS SAT Amps were upgraded per ECR E2400330. Modification improves the whitening stage to reduce ADC noise from 0.05 to 10 Hz. The EX PUM SAT Amp was NOT upgraded.
Suspension | Old | New | OSEM |
ETMX MO | S1100128 | S1100075 | F1F2F3SD |
ETMX MO/RO | S1100079 | S1100163 | RTLF/RTLF |
ETMX RO | S1100149 | S1100132 | F1F2F3SD |
ETMX UIM | S1000297 | S1100140 | ULLLURLR |
TMSX | S1100098 | S1100150 | F1F2F3LF |
TMSX | S1000292 | S1100058 | RTSD |
MC2 | S1100107 | S1100071 | T1T2T3LF |
MC2/PR2 | S1100087 | S1100147 | RTSD/T1T2 |
PR2 | S1100172 | S1100121 | T3LFRTSD |
F. Clara, J. Kissel
As of 2025/07/25 00:00 UTC, the TMSX satamp box for F1/F2/F3/LF has been swapped from S1100150 to S1100122
See 85980 for more info
Here's the characterization data and fit results for S1100075 , assigned to ETMX M0's F1F2F3SD OSEMs (Fil refers to this as ETMX MO F1F2F3SD). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100075_ETMX_M0_F1F2F3SD_20250710.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design ETMX M0 S1100075 CH1 F1 0.0971:5.31 120 zpk([5.31],[0.0971],1,"n") CH2 F2 0.0973:5.33 120 zpk([5.33],[0.0973],1,"n") CH3 F3 0.0979:5.36 120 zpk([5.36],[0.0979],1,"n") CH4 SD 0.0953:5.21 120 zpk([5.21],[0.0953],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 discusses, I'm intentionally excluding the fit of transimpedance gain from the foton design string, and so I've stopped using the R_TIA_kOhm as a knob in my by-hand fitting of the zeros and poles. Hence, you'll find that from here on, R_TIA_kOhm will almost always be the default 120 kOhm value I've found that works with the measured data and changing only the zero:pole frequency.
Here's the characterization data and fit results for S1100163 , assigned to ETMX M0/R0's LFRT/LFRT OSEMs (Fil refers to this as ETMX MO/RO RTLF/RTLF above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100163_ETMX_M0R0_LFRTLFRT_20250710.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design ETMX M0R0 S1100163 CH1 LF 0.0948:5.18 120 zpk([5.18],[0.0948],1,"n") CH2 RT 0.0954:5.21 120 zpk([5.21],[0.0954],1,"n") CH3 LF 0.0969:5.30 120 zpk([5.30],[0.0969],1,"n") CH4 RT 0.0947:5.17 120 zpk([5.17],[0.0947],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm.
Here's the characterization data and fit results for S1100132 , assigned to ETMX R0's F1F2F3SD OSEMs (Fil refers to this as ETMX RO F1F2F3SD above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100132_ETMX_R0_F1F2F3SD_20250710.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design ETMX R0 S1100132 CH1 F1 0.0943:5.17 120.75 zpk([5.17],[0.0943],1,"n") CH2 F2 0.0960:5.25 121.00 zpk([5.25],[0.0960],1,"n") CH3 F3 0.0963:5.28 121.25 zpk([5.28],[0.0963],1,"n") CH4 SD 0.0970:5.33 120.75 zpk([5.33],[0.0970],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ This sat amp actually needed some fit transimpedance gain, so I report it here. But, again, it's not used in the compensation filter.
Here's the characterization data and fit results for S1100140 , assigned to ETMX L1's ULLLURLR OSEMs (Fil refers to this as ETMX UIM ULLLURLR above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100140_ETMX_L1_ULLLURLR_20250715.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design ETMX L1 S1100140 CH1 UL 0.0943:5.14 120.5 zpk([5.14],[0.0943],1,"n") CH2 LL 0.0965:5.26 120.5 zpk([5.26],[0.0965],1,"n") CH3 UR 0.0943:5.14 120.5 zpk([5.14],[0.0943],1,"n") CH4 LR 0.0961:5.24 120.5 zpk([5.24],[0.0961],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ Similar to S1100132, I found I needed to slightly adjust the transimpedance to get a good phase fit of the zero frequency while getting magnitude scale to the ~1.000 +/- 0.005 level. Again, this won't be used in the compensation filter.
Here's the characterization data and fit results for S1100122 , which -- per LHO:85981, LHO:85980 and after 2025-07-25, has been assigned to TMSX M1's F1F2F3LF OSEMs (Fil refers to this as just TMSX F1F2F3LF above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100122_TMSX_M1_F1F2F3LF_20250724.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design TMSX M1 S1100122 CH1 F1 0.0962:5.26 120 zpk([5.26],[0.0962],1,"n") CH2 F2 0.0971:5.31 120 zpk([5.31],[0.0971],1,"n") CH3 F3 0.0957:5.24 120 zpk([5.24],[0.0957],1,"n") CH4 LF 0.0951:5.20 120 zpk([5.20],[0.0951],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm.
Here's the characterization data and fit results for S1100058 , assigned to TMSX M1's RTSD OSEMs and CH3CH4 are not connected to any OSEM in-vacuum, hence the "xxxx" place holders (Fil refers to this as just TMSX RTSD above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100058_TMSX_M1_RTSDxxxx_20250708.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design TMSX M1 S1100058 CH1 RT 0.0939:5.11 121 zpk([5.11],[0.0939],1,"n") CH2 SD 0.0960:5.25 120 zpk([5.25],[0.0960],1,"n") CH3 xx 0.0955:5.23 120 zpk([5.23],[0.0955],1,"n") CH4 xx 0.0961:5.25 120 zpk([5.25],[0.0961],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is (mostly) the default 120 kOhm, save for CH1.
Here's the characterization data and fit results for S1100071 , assigned to MC2 M1's T1T2T3LF OSEMs (Fil refers to this as just MC2 T1T2T3LF above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100071_MC2_M1_T1T2T3LF_20250710.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design MC2 M1 S1100071 CH1 T1 0.0977:5.34 120 zpk([5.34],[0.0977],1,"n") CH2 T2 0.0956:5.23 120 zpk([5.23],[0.0956],1,"n") CH3 T3 0.0948:5.18 120 zpk([5.18],[0.0948],1,"n") CH4 LF 0.0958:5.22 120 zpk([5.22],[0.0958],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm.
Here's the characterization data and fit results for S1100147 , assigned to MC2/PR2 M1's RTSD/T1T2 OSEMs (Fil refers to this as just MC2/PR2 RTSD/T1T2 above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100147_MC2PR2_M1_RTSDT1T2_20250710.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design MC2 M1 S1100147 CH1 RT 0.0975:5.33 120 zpk([5.33],[0.0975],1,"n") MC2 M1 CH2 SD 0.0947:5.18 120 zpk([5.18],[0.0947],1,"n") PR2 M1 CH3 T1 0.0969:5.29 120 zpk([5.29],[0.0969],1,"n") PR2 M1 CH4 T2 0.0962:5.25 120 zpk([5.25],[0.0962],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm.
Here's the characterization data and fit results for S1100121 , assigned to PR2 M1's T3LFRTSD OSEMs (Fil refers to this as just PR2 T3LFRTSD above). The data was taken per methods described in T080062-v3. The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ plotresponse_S1100121_PR2_M1_T3LFRTSD_20250710.m Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are Optic Stage Serial_Number Channel_Number OSEM_Name Zero_Pole_Hz R_TIA_kOhm Foton_Design PR2 M1 S1100121 CH1 T3 0.0979:5.37 120 zpk([5.37],[0.0979],1,"n") CH2 LF 0.0967:5.29 120 zpk([5.29],[0.0967],1,"n") CH3 RT 0.0958:5.24 120 zpk([5.24],[0.0958],1,"n") CH4 SD 0.0969:5.31 120 zpk([5.31],[0.0969],1,"n") The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/ As LHO:85626 and the above LHO:86028 discusses, R_TIA_kOhm is the default 120 kOhm.