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  17916   Mon Oct 23 22:35:53 2023 PacoUpdateLSCFPMI CARM with CM board

[paco, yuta]

We achieved a ~23 kHz CARM bandwidth this evening when locking FPMI using the CM Board.


  • REFL55_Q_MON to IN1 of CM Board.
    • The REFL55 RFPD demod angle is conveniently 92 deg, so REFL55_I (CARM error point) = REFL55_Q_MON
  • AO to MC Servo Board
  • Moku:Pro Freq response analyzer used to measure the CM Board loop
    •  TP1 (CMB) to IN1 (Moku) and TP2 to IN2 points around the first OUT2 (Moku) to EXC (CMB).
  • The gain sliders we used were REFL1 Gain (+23 dB) and AO Gain (max +18 dB before we see loop oscillations).
  • No Boost could be enabled, regardless of the polarity.
  • Apparently both polarities were good for this lock (why?)

See Attachment #1 for the MEDM screenshot.


The inferred CARM UGF is ~ 23 kHz, as can be seen from Attachment #2 and using the loop algebra described in (40m/17628). Instead of the definition in 40m/17628, we plotted the following for the inferred CARM HBW loop OLTF (with all the other loops off).


Now the OLTF of CARM loop measured at CARM Common Mode Board with all the loops on can be calculated as

G_meas = G_CARM / (1 + G_IMC) / (1 + G_LSC/(1 + G_IMC) )

where G_LSC/(1 + G_IMC) is the OLTF for CARM digital LSC loop, with IMC loop on, which is usual CARM LSC OLTF we measure digitally.
(ORANGE texts added by YM on Oct 25 at 17:40 to update G_CARM definition to clarify; see 40m/17920 for loop algebra)

Attachment #3 shows the calibrated DARM readout with and without the CM Board feedback enabled. We can only assert the noise dropped slightly around 50-100 Hz, but not a lot (which is good in a sense).


  • Check BOOST and Polarity, maybe incorporate an independently measured BOOST transfer function into the model to understand better. 
Attachment 1: CMB_medm_CARM_FPMI_20kHz_Screenshot_2023-10-23_22-40-59.png
Attachment 2: HighBWCARMmodel.pdf
Attachment 3: FPMI_calibrated_noise_20231023_HBW.pdf
  17915   Mon Oct 23 16:41:22 2023 KojiSummaryBHDBHD Platform

Thanks, JC for putting the parts together! I'll start collecting the instruments necessary for the OMC mounting / locking.

  17914   Mon Oct 23 16:32:38 2023 yutaUpdateLSCPRMI 1f carrier locking recovered, but not so stable

[Vittoria, Yuta]

We restored the alignment after c1sus2 crash (40m/17911).
Both FPMI and PRMI sensitivities look consistent with the recent measurements.

What we did:
 - Realigned PMC to get C1:PSL-PMC_PMCTRANSPD of 0.68
 - Realigned IMC to get C1:IOO-MC_TRANS_SUMFILT_OUTPUT of 12900-ish (might be able to tune more)
 - Realigned YARM and XARM. Both arms were not flashing when we started. ITMY OSEM was stuck and YAW kick was applied to unstack. All the related suspensions required quite a bit of alignment tuning especially in pitch.
 - Locked FPMI with REFL55 and AS55, and measured the sensitivity (Attachment #1)
 - Locked PRMI in carrier, and measured the sensitivity (Attachment #2)
 - Resulting alignment is in Attachment #3

 - Stabilize PRMI lock.
 - Measure actuator efficiencies of PR2, PR3, SR2, AS1, AS4, LO1, LO2, and roughly estimate angular actuator efficiencies for all the suspensions.
 - Dither each suspension during PRY, PRX, SRX, SRY locks to see beam spot positions on vertex suspensions to check clipping to prepare for vent.

Attachment 1: FPMI_calibrated_noise_20231023.pdf
Attachment 2: MICH_Sensitivity_20231023.pdf
Attachment 3: Screenshot_2023-10-23_16-32-03_PRMI_FPMI_alignment.png
  17913   Mon Oct 23 15:38:19 2023 KojiUpdateCDSDolphin Fencing Investigation / Full CDS crash / nodus reboot / recovered all

There should be a correct wrapper script such that we don't need to do nonsense like remembering the IP address and the port number.
The timing of disabling and enabling is important too...


  17912   Mon Oct 23 14:42:17 2023 JCSummaryBHDBHD Platform

Today, I spent majority of my time insterting the Helicoils for the Platform Assembly, D2100435. 181 Inserts to be exact.angry and I also got around to setting up the build for up the D2200400, 405, and 406. I expect for the assembling of the BHD platform to be maxed by Friday. (Maxed as in we need to pull parts from which are currently in Vacuum). I want OMC to be added on Friday and for us to begin the following week with alignment of the BHD Assembly.

Tasks which still need to be done

  • Assembly of D2200400, 405, and 406.
  • Bring over OMC and install onto the platform.
  • Alignment of the BHD and OMC.
  • Optic-Fibre input to the cleanroom.


Attachment 1: IMG_7049.jpeg
Attachment 2: IMG_7050.jpeg
Attachment 3: IMG_7051.jpeg
  17911   Mon Oct 23 14:08:57 2023 JCUpdateCDSDolphin Fencing Investigation / Full CDS crash / nodus reboot / recovered all

We used this technique earlier and we came across a mistake while we were following the steps from the elog. (The Wiki is better, here : https://wiki-40m.ligo.caltech.edu/CDS/DolphinSwitch)

When inserting the IP Address for Steps 1 and 4, you must denote the correct machine by its assigned number from Wiki.

./dolphin_ix_port_control.sh --disable # 

Yuta and I made this mistake, used the IP Address of C1SUS2, and DK turned on for c1x04, c1x02, and c1x03.

The systen was brought back up using the technique correctly and all systems were burtRestored to Oct/23/00:19



Dolphin Fencing technique

I believe that the dolphin emits some glitches to the other hosts during the host machine shutting down and starting up.
However, if the dolphin is disabled, that FE process will not run.

Therefore, we need some technique:

  • When you have a real-time host to be restarted, we can disable the dolphin of that machine.
    e.g. If c1lsc has a problem, run the following command on fb1.
    ./dolphin_ix_port_control.sh --disable 2
    This allows us to restart the c1lsc in a safe way.
  • Restart c1lsc in the above example. Go to c1lsc and run
    sudo reboot; exit
  • This above brings you back to the previous host you were (suppose it is fb1). Run ping on that restarting machine.
    ping c1lsc
  • While the c1lsc is shutting down, ping still has the response. Once the restart starts, it makes no response. Then, you can enable dolphin.
    ./dolphin_ix_port_control.sh --enable 2
  • The process comes back automatically. You'll see DK status during the restart. I should disappear once all the models are up.



  17910   Fri Oct 20 15:51:21 2023 JCSummaryBHDBHD Platform

The BHD platform assembly is going well. I have gotten majority of the Helicoils into all of their components. The only Helicoils I have left to insert are those of the breadboard. I have finished assembling 4 of the D220392, and 2 of the D2200409. Next I will be inserting the HeliCoils into the breadboard and working on D200400, D200405, and D200406. If lucky, I will also be able to tackle the Optic Mount Assemblies D2100200 and 2100435 on Monday afternoon as well.


I've attached a photo of the finished components.

Attachment 1: IMG_7033.jpeg
Attachment 2: IMG_7035.jpeg
  17909   Thu Oct 19 13:54:16 2023 PacoUpdateLSCFPMI locking and high BW CM board

[Paco, yuta]

We investigated the situation of the CM board again this morning. We measured the transfer function from IN1/IN2 to TPs/AO and changed the configuration around every time. We noticed slider gains such as REFL1 Gain / REFL2 Gain / AO Gain / SUPER BOOST had absolutely no effect but binary switches such as BOOST / OPTION / G=1, z=1.6 kHz, p=79Hz were working correctly. We also noticed the bit word at the bottom right corner of some sliders was always 0x0, in contrast with the MC Servo IN2 Gain which at -32 dB indicated 0xffe0. This made us look into the modbus related files in c1iscaux under /cvs/cds/caltech/target/c1iscaux where we discovered the latch.py script. After browsing the elog and wiki a little more, we realized there is a logic implemented in this slow channels to prevent sudden gain switchings, but we still don't fully understand how it is running or where? What we did find was that somehow c1iscaux was running a python script (latch.py?), and according to top it has been running for a little over 79 hours (but where/why/how?).

After killing the python3 processes in c1iscaux, we recovered the CM board slider functionality (but why?) and verified the transfer functions are getting the right gains. We also checked the Offset (V) and noted that when sliding to +-10 Volts the resulting offset was +-95 mV. I confirmed through the schematic (+ Koji) that the +- 10 V bias from the slow DAC is reduced by the trim circuit shown in Attachment #1 so this is also working properly. To reflect this, I updated the medm screen to mimic what is done in the MC servo board screen (includes the division from the raw DAC offset to the summing junction in the signal chain), see the result in Attachment #2.

Attachment 1: CMboard_OFFSET_schematicScreenshot_2023-10-19_14-59-48.png
Attachment 2: CMBOARDmedm_Screenshot_2023-10-19_15-27-17.png
  17908   Thu Oct 19 07:14:44 2023 JCUpdateIOO Morning Alignment

Basic Arm Alignment has been done

  • WFS seemed to have railed overnight.
    • The first action I took this mornign was to turn wfs off. Once I saw that I holding well, I ran the 60s WFS Relief script.
  • I align the single arms, C1:LSC-TRY_OUT_DQ transmission to ~1.0 and C1:LSC-TRX_OUT_DQ ~ .8

I'm going to continue working on the BHD platform now.

The first assemblies I am working on are D2200406, D2200154,and D2200392.

  17907   Wed Oct 18 21:21:58 2023 PacoUpdateLSCFPMI locking and high BW CM board

[Paco, yuta]


- We recovered the FPMI lock after aligning YARM, XARM and MICH. For this, the TT1,TT2 PITCH were adjusted quite a bit, but the arm cavity transmission was steady and close to 100%. 

- MICH seemed slightly unstable, so we checked a few things. (1) The noise spectrum showed excess noise around 300 Hz with a forest of high frequency peaks around  seemingly spaced by a constant ~ 9.8 Hz. Reducing the DARM loop gain from 0.044 to 0.030 (UGF reduced from 200 t0 150 Hz) helped in lowering the overall 300 Hz noise (Attachment #1), but the 9.8 Hz peaks remained (Attachment #2). (2) The MICH UGF was 30 Hz, as expected. Furthermore, we noted the IR transmission in both arms was coherent with the AS55_I_ERR signal when FPMI was locked (Attachment #3).

- To try and improve our MICH situation, we tried disabling the BS OPLEV loops but this didn't have an effect. We also tuned  the demod phases for REFL55 and AS55 RFPDs. The changes were made to minimize the CARM content in both signals:
    REFL55 from 96.22 to 94.13
    AS55 from -166.00 to -159.77
which didn't seem to help this issue but made our lock acquisition better.

This issue remained for tonight, and we decided to move on to investigating the CM Board situation.

CM Board

- The expectation is to achieve "mid-BW" CARM loop of a few kHz to couple of 10 kHz with FPMI. This is because the CM board is modified to match the PRFPMI CARM pole (~200 Hz) and is not expected to be stable for a "high-BW" single ARM pole (~4 kHz) at its highest gain configuration. So the goal is to recover the mid-BW ARM/CARM lock (see 40m/17628 for what we did last time in June 2023).

- We first locked YARM using POY11_I_ERR (UGF ~ 200 Hz) and then connected the POY11_I_MON signal from the IQ demod board to the IN1 of the CM board. 
- We decided to also connect REFL55_Q_MON to IN2 (note that because of the ~ 90 deg demod angle above, REFL55_Q_MON conveniently carries the equivalent to REFL55_I_ERR used as the CARM error point). 
- We hooked up the moku pro to TP1, TP2 and (enabled) EXC ports at the first stage and enabled the AO output to MC Board IN2 (which was disconnected for some reason)
- We added input gain to the IN1 (YARM) but didn't really break the lock even when we expected it to break (>+30 dB, >0 dB), so we suspected something was wrong with the board.

- After connecting two test points to a scope, we moved the REFL1_IN_GAIN slider around but couldn't see an effect on the TP1 signal... The boost, polarity and offset seemed to work (although applying a 3 Volt offset had the effect of ~30 mV offset at the scope). 

We suspect the CM board is not working appropriately, so we will continue debugging it tomorrow. 

Attachment 1: FPMI_calibrated_noise_20231018.pdf
Attachment 2: FPMI_calibrated_noise_20231018_forest.pdf
Attachment 3: FPMI_TRXY_ASDC_AS55I_Screenshot_2023-10-18_21-54-28.png
  17906   Wed Oct 18 13:01:52 2023 JCSummaryDaily ProgressLab WiFi

!!We Now Have WiFi Through The Entire Lab!!

Paco and I connected the new routers and expanded the wifi network throughout the lab. These are connected in a "bridge" type of way so that our WiFi doesn't disconnect when we reach the ends. I have also added labels along the ethernet cable to make it easy for us to follow if we run into any issues later on. The Ethernet cable which runs down the Y-Arm is Red and the Ethernet cable which runs down the X-Arm is Blue. The router for the Y- Arm is located on top of the 1Y4 Rack and the X-Arm router is located on the

Attachment 1: IMG_7026.jpeg
Attachment 2: IMG_7028.jpeg
  17905   Wed Oct 18 12:29:19 2023 PacoUpdateSUSOPLEV Whitening Board Fixed and installed (ETMX)

[Murtaza, Paco, Radhika]

We got some LT1128s from downs (Dean) to get this board up and running again. We first did a test replacement on Ch2 (since Ch1 was working) and got the desired transfer function (z=1, p=[10, 1000]) measured up to the test point. We ended up replacing a total of 5 ICs, all 1128s, and the board seems fine now. See Attachments #1-2 showing which ICs we replaced and a snap of the TF measured using 100 mV of source amplitude to avoid saturation.

Wed Oct 18 15:26:38 2023 Updated the dcc entry reflecting these changes cool


Attachment 3 shows the original state, plus the unconnected whitening board installed to the right of the oplev board. Here the oplev board output ribbon cable was sent directly to the AA chassis input 21-24. We then routed the oplev monitors to the whitening board (via 1-->2 pin LEMO cables) and send the whitening board output to the AA chassis input 21-24 [Attachment 4]. We verified the board was drawing current; this concluded the install.

Attachment 1: PXL_20231017_235334773.MP~2.jpg
Attachment 2: PXL_20231017_235837540.MP.jpg
Attachment 3: IMG_5818.JPG
Attachment 4: IMG_5819.JPG
  17904   Wed Oct 18 12:20:26 2023 JCUpdateFrequency noise measurementSpectrogram Using GWpy



I was able to make a spectrogram of Mc Frequency noise using the gwpy package in Jupyter. The channel I grabbed data from was C1:IOO-MC_FREQ_OUT16 because the code didn't seem to like "C1:IOO-MC_FREQ_OUT" very much.

Anyways, I was running into the issue of plotting the spectrogram using TimeSeries.get(~~~~) in mycode. The error i was getting was "TimeSeries has no attibute" It turned out that I was using the wrong plotting function. The correct way was the use the xyz.plot(norm='log', vmin=MinValue, vmax=MaxValue) with 'xyz' being the name you assigned to you spectrogram data. The graph looked odd to me at first, but it turned out that I was using the PSD, so after Sqrt-ing it,  the plot looked a ton of a lot better.


As of now, this code is on Rossa. So next, I have to work on getting this on the big screen in the control room and passively updating every 5 minutes. This means getting the CDS environment CORRECTLY installed correctly on Stella.


Please keep in mind that this is not finished. Proper labels and cooler axes will be added. This is just what I have going as of now. smiley

Attachment 1: MC_F__SPECGRAM.png
  17903   Tue Oct 17 19:35:31 2023 RadhikaUpdateASSReducing XARM-ASS Errors

I resumed work to restore XARM ASS

I manually aligned XARM and calculated the output matrix using scripts/ASS/getASSOutMat.py. This script gives an offset to the ETM/ITM/BS in pitch and yaw and records all error signals to construct a sensing matrix (8 err signals x 6 actuators). Then the ITMX PIT/YAW L error signal rows are removed (as per XASS historical practice) and the resulting square matrix is inverted.

A few times I loaded the output matrix and turned up the ASS servo gain, but this caused error signals to diverge and transmission to drop. I realigned XARM in between each time and recalcuated the output matrix until one looked promising [Attachment 1].

- From a decently aligned state, the servo maintained transmission and controlled error signals began to converge to 0.

- However when I gave an offset to some optic, transmission started to recover but then dropped even as all controlled error signals were minimized [Attachment 2]. A zoomed version of this is in Attachment 3.

     - ITMX PIT L (light blue) / ITMX YAW L (light pink) are uncontrolled

     - ETMX PIT L (dark blue) has a ~0.2 Hz oscillation, but its mean error is roughly 0. This behavior has been present since XASS stopped working, but it is yet to be understood.

The output matrix is successfully reducing the error signals it controls, but transmission is not maximized. I wonder if it's stuck in a local minimum, but I haven't convinced myself that these error signals can be 0 when the beam spots aren't centeredand cavity/beam axes aren't matched. Maybe we need to use the ITMX PIT/YAW L error signals.

Things to try:

1. Assume pitch and yaw are decoupled and calculate a checkerboard output matrix, and debug each angular DOF at a time. I briefly did this today and got the pitch loop to increase transmission, but not the yaw loop.

2. Altering the sensing matrix to include ITMX PIT/YAW L error signals. Then I'll use the same script to compute the output matrix.

Attachment 1: XASS_dense_output_matrix_channels.png
Attachment 2: XASS_dense_output_matrix.png
Attachment 3: XASS_dense_output_matrix_zoomed.png
  17902   Mon Oct 16 20:50:32 2023 PacoUpdateIOOsome IMC WFS tweaks: update - MC_TRANS +80dB FM5 back on

Since the MC_TRANS_PIT and MC_TRANS_YAW control signals were still small even though the sum was ok, I found the C1:IOO-MC_TRANS_PIT/YAW FM5 error point filter which was a +80 dB compensation of the -80 dB C1:IOO-MC2_TRANS_PIT/YAW servo filter was off. This is probably a result of poorly updated snap files so burt missed it after recent model restarts. I will keep an eye on the WFS in the short-term. Attachments #1-3 show the relevant filter locations.

Attachment 1: MC_TransScreenshot_2023-10-17_03-53-42.png
Attachment 2: plus80dB_Screenshot_2023-10-17_03-54-57.png
Attachment 3: minus_80dBScreenshot_2023-10-17_03-55-12.png
  17901   Mon Oct 16 19:37:12 2023 yutaUpdateLSCPRMI 1f carrier locking recovered, but not so stable

PRMI 1f carrier locking using AS55_Q and REFL55_I was recovered, but only stays for ~30 sec so far.

Configuration changes:
 - C1:LSC-PRCL_GAIN was increased to -0.011 from -0.0054 to compensate for PRM actuation decrease by half (40m/17886).
 - MICH actuator was changed to 0.5*BS - 0.915*PRM from 0.5*BS - 0.307*PRM to compensate for BS and PRM actuation changes (40m/17886).
 - These updated parameters are saved in /opt/rtcds/caltech/c1/Git/40m/scripts/LSC/PRMI-AS55_REFL11.yml

 - These changes gave PRCL UGF of ~200 Hz (Attachment #1), which is consistent with past measurements (40m/17696).
 - MICH UGF was ~150 Hz (Attachment #2), which is three times higher than past measurements (40m/17696). BS actuation was changed only by about 40%, som I'm not sure why.
 - C1:LSC-POPDC_OUT is about 1500-1700, when maximum. It fluctuates a lot (Attachment #3), and lock is stable only for 30 seconds or so.
 - PRCL sensitivity looks almost the same as what we measured in August, but has some excess noise above ~70 Hz (Attachment #4).
 - MICH sensitivity looks almost the same as what we measured in August (Attachment #5).
 - Current IFO alignment is shown in Attachment #6.

 - BS damping loops look strange. Too much coupling betwen DoFs. Input matrix needs to be investiaged.
 - Recover PRMI 3f

Attachment 1: Screenshot_2023-10-16_18-36-51_PRCLOLTF.png
Attachment 2: Screenshot_2023-10-16_18-39-43_MICHOLTF.png
Attachment 3: Screenshot_2023-10-16_18-34-42_PRMI1f.png
Attachment 4: PRCL_Sensitivity_20231016.pdf
Attachment 5: MICH_Sensitivity_20231016.pdf
Attachment 6: PRCL_alignmentScreenshot_2023-10-17_02-35-53.png
  17900   Mon Oct 16 08:28:27 2023 JCUpdateVACN2 tripped and Vac locked

The last N2 tank ran out this morning ~3:00am. Since then the Vac system tripped and the shutter closed. I had to head over to the shipping dock and pick up a tank myself, but the system is back up and I am now aligning. I've attached the nominal Vacuum state below. This is what we want to be at whenever bringing the vacuum system back up.     

Attachment 1: Screenshot_2023-10-16_08-29-40.png
  17899   Fri Oct 13 08:42:14 2023 murtazaUpdateSUSOPLEV Whitening Board Missing (ETMX)

[Yuta, Paco, Murtaza]


Chasing the excess noise in TRX, Yuta suspected the whitening-dewhitening situation for the ETMX.
We compared the OPLEV spectrum for the IFO optics to gauge the situation. The spectrum with dewhitening filters (p = 1Hz, z = 10Hz) (FM3, FM4) 
-Active for all optics (Attachment 1)
-Deactive for ETMX (Atachment 2)

Attachment 1: ETMX >1Hz shows the extra dewhitening filter applied which concludes a misisng analog whitening filter (which it is supposed compensate for)

We compared the X-end with the Y-end rack and found the whitening board for ETMX OPLEVs missing (Pentek Generic Input Board).
We found the board but could not determine the reason for the missing board in previous elogs.

We proceeded to check the board for potential damage. To do this, we we evaluated the transfer functions the filters.

- The board schematic does nott exist on D020432 anymore and is moved to D1500270 (The label on the board says D020432)
- The schematic does not record the modified values for the resistors and capcacitors to place the pole-zero pair at 1, 10Hz
- The transfer functions were evaluated using a swept sine measurement from the {input}-> {1st header, 2nd header, tie point} (for example, {J3} -> {J1, J2, T1}) for the first 4 filters (which had existing connections) (Attachemnt 6)
- A good transfer function ( Attachment 3)  is expected with the filter design was obtained on a few ports ; others looked garbage (Attachment 4)
- Attachment 5 shows the good/bad outputs

Summary of QPD filter whitening situations:
 - ETMX and ETMY oplevs have whitening (not now for ETMX) of two 10:1 (D020432, which is actually D1500270)
 - TRX and TRY QPDs have whitening of two 40:4 (D1400415, D1400414)
 - ITMX and ITMY oplevs have whitening of two 10:1 (D020432, which is actually D1500270)
 - BS, PRM, SRM oplevs and MC2 TRANS QPD do not have whitening
 - They are always on and compensated with digital anti-whitening filters (not now for ETMX; for now, ETMX digital anti-whitening filters are turned off to have better oplev damping).

Attachment 1: ETMX_DW_active.png
Attachment 2: ETMX_DW_deactive.png
Attachment 3: IMG_9666.jpg
Attachment 4: IMG_9670.jpg
Attachment 5: IMG_9695.jpg
Attachment 6: IMG_9667.jpg
  17898   Thu Oct 12 18:47:52 2023 yutaUpdateLSCALS DARM CARM locking successful

ALS DARM and CARM locked.
The procedure basically follows what have already been done in 40m/17764 (YARM IR to ALS), 40m/17768 (XARM IR to ALS), and 40m/17819 (CARM IR to ALS).

 - Lock electronic DARM and CARM using POX11_I and POY11_I as we do everyday.
 - Lock both Y and X green.
 - Setup DFD, reset phase tracker phases, as we do everyday.
 - Measure relative gains, including signs, between C1:LSC-ALSY_OUT and C1:LSC-POY11_I_ERR, C1:LSC-ALSX_OUT and C1:LSC-POX11_I_ERR by dithering CARM at 13.3 Hz.
 - Balance them using measured relative gains. (balanceChannels.py)
 - Remove offsets from C1:LSC-ALSY_OUT and C1:LSC-ALSX_OUT using C1:LSC-ALS*_OFFSET. (putAvg.py)
 - Slightly reduce gains (probably not so necessary, but will create more phase margin)
    C1:LSC-DARM_GAIN: 0.044 to 0.04
    C1:LSC-CARM_GAIN: 0.011 to 0.008 

 - Hand off from POX11_I +/- POY11_I to ALSX +/- ALSY.

  - The time series of the last two steps are shown in Attachment #1
    At -30s-ish, CARM was handed off (POX and POY noisier)
    At -20s-ish, DARM was handed off (POX and POY further noisier)
    At -5s-ish, DARM and CARM offsets where added.
 - The procedure is fully automated, and the configuration file live in:
 - DARM sensitivity with DARM locked with ALS DIFF is shown as magenta line in Attachment #2. Compared with IR RF lock in blue, it is noisier above 30 Hz.
 - Using POX11_I as an out-of-loop sensor, residual DARM RMS is about 0.9e-10 m.

 - Fix ETMX oplev QPD whitening situation
 - Try ALS assisted FPMI
 - Restore PRMI 1f 3f locking
 - Lock PRFPMI

Attachment 1: Screenshot_2023-10-12_18-25-37_ALSCARMDARM.png
Attachment 2: Screenshot_2023-10-12_19-00-55_ALSDIFF.png
  17897   Wed Oct 11 22:57:11 2023 PacoUpdateALSOn the residual frequency dependence of the ALS DARM calibration with FPMI

[Paco, Yuta]

Attachment #1 shows tonights OOL ALS noises with the PSL hepa OFF, and arm cavities locked using POX/POY.

This evening during an FPMI lock stretch we took transfer functions from C1:LSC-DARM_IN2 to C1:ALS-BEATXY_FINE_PHASE_OUT (the individual ALS beat sensing points) to reproduce the measurement described by Anchal in (40m/17562) and also reported in his thesis. The diaggui template for this measurement was saved under /users/Templates/ALS/BEATXY_DARM_TF.xml

Anyways the residual frequency dependence shown in Attachment #2 and seems less dramatic as previously described, amounting to <10% over the DFD + phase tracker bandwidth (2kHz) and with a low excitation SNR (~ 2). According to our previous estimate there was > 100% across the same frequency band.

Wait, what?

Recently, we straightened DW switching on ETMY (40m/17875) so the DARM actuation is definitely homogeneous because both ETMY and ETMX are in the same (acquisition) mode. Before ETMY had a weird mix of DW switches. Another possibility is that the previous measurement excited only the YARM length (actuating on ETMY) thus creating a CARM as well as DARM signal which was seen by the ALS beat. This seems like a perfect recipe for confusion.

Hence I will  focus on high bandwidth CARM locking in the context of PRFPMI locking for BHD, and stop this Hi-BW CARM for calibration witch hunt.

Attachment 1: ALS_OOL_Screenshot_2023-10-11_23-05-58.png
Attachment 2: BEAT_DARM_TFs_Screenshot_2023-10-11_23-12-37.png
  17896   Wed Oct 11 21:23:49 2023 yutaUpdateLSCFPMI locking restored after vertex coil driver upgrade

[Murtaza, Vittoria, Paco, Yuta]

We restored FPMI RF locking for the first time after the vertex coil driver upgrade.
RF demodulation angles changed a quite bit.
We observed excess noise in YARM, XARM single arm configurationsno, but not in FPMIyes.

YARM and MC_F noise measurements:
 - The noise spectra were taken when YARM is locked with POY11 using ETMY as an actuator.
 - Compared with the noise spectra taken in August 2023 (dashed lines; 40m/17766) before the upgrade, YARM noise has excess noise around 40-300 Hz, and MC_F has some excess noise around 40Hz (Attachment #1).
 - 60 Hz noise peak in MC_F seems nominal, but in YARM it is about an order of magnitude larger (Attachment #2; it should be about 10 Hz/rtHz or 1.4e-12 m/rtHz with bandwidth of 0.187493 Hz; see 40m/17461). This is not as bad as misconfigured MC1 and MC3 dewhitening; it used to give two orders of magnitude increase at 60 Hz.
 - 60 Hz noise peak in YARM could be because of lack of analog 28 Hz ELP now (see 40m/17466). Turning on/off digital 28 Hz ELP filters in MC1 and MC2 coil outputs didn't change the situation. Turning on/off IMC WFS also didn't change the excess noise.
 - Excess noise in YARM could be from vertex coil driver upgrade.
 - We don't see clear excess noise around 1 Hz, so suspension dampings are probably not so bad.

 - The same story for XARM (Attachment #3 and #4). Now the dashed lines are from August 2022, even before the ETMX coil driver upgrade (happened in June 2023)

IFO alignment:
 - BHDC_A and B seems to be degraded from their nominal values of ~34 to ~27 (see below and 40m/17671). We might need to play with TT1/2 and PR2/3 to do YARM alignment. Or may be LO alignment is not compatible with PRC alignment.
 - TRX also fluctuates too much compared with TRY. This seems to be coming from ETMX motion (see Attachment #5). This was taken at around 4pm, but it will be much better in the night (Attachment #10).

C1:PSL-PMC_PMCTRANSPD 0.6865958929061889 0.0007320942064261143
C1:IOO-MC_TRANS_SUMFILT_OUT 13215.416015625 22.983493891497357
C1:LSC-TRY_OUT_DQ 1.0542557954788208 0.012796686190180762
C1:HPC-BHDC_A_OUT -26.42974987030029 0.5681787139183535
C1:HPC-BHDC_B_OUT -28.60767822265625 0.630590120803355
C1:LSC-TRX_OUT_DQ 0.8131266951560974 0.06610630013789652

FPMI locking:
 - We had to change the following parameters to restore FPMI locking.

C1:LSC-OUTPUT_MTRX CARM to MC2 component to -1.65 (from -0.734, to account for MC2 actuation being about a half now; see 40m/17886)
C1:LSC-AS55_PHASE_R to -166 (from -177.9, to minimize CARM to AS55_Q coupling)
C1:LSC-REFL55_PHASE_R to 96.22 (from 75.92, to minimize CARM to REFL55_Q coupling)
C1:LSC-PD_DOF_MTRX REFL55_I to CARM_B component to 0.4536 (from 0.567, to balance between POX11_I+POY11_I)

 - These new values were obtained using SENSMAT and transfer function measurements between DARM_A and DARM_B (Attachment #6), CARM_A and CARM_B (Attachment #7). Red is measured OLTF, and blue is expected OLTF when using "B" signals (real FPMI RF signals). Red and blue should be equal to hand off.
 - Measured UGF was ~150 Hz for DARM (Attachment #6), ~200 Hz for CARM (Attachment #7), and ~30 Hz for MICH.
 - FPMI noise spectra was measured, and compared with that from January 2023 (Attachment #8). FPMI sensitivity looks the same as before angel. 60 Hz noise is also not worse, probably because of common mode rejection.

 - Investigate ETMX damping
 - Investiage clipping in IFO to make a check list for the vent
 - Investigate excess noise in single arm. Possibly from MC dewhitening filters? (not a problem right now)
 - Restore PRMI 1f and 3f lockings
 - Restore ALSY and ALSX
 - Try high bandwidth CARM (if necessary)
 - Lock PRFPMI with ALS

Attachment 1: Screenshot_2023-10-11_15-42-53_YARMNoise.png
Attachment 2: Screenshot_2023-10-11_15-43-35_YARMNoise60Hz.png
Attachment 3: Screenshot_2023-10-11_15-44-18_XARM.png
Attachment 4: Screenshot_2023-10-11_15-45-03_XARMNoise60Hz.png
Attachment 5: Screenshot_2023-10-11_16-19-26_ETMXmotion.png
Attachment 6: Screenshot_2023-10-11_21-19-57_DARM_OLTF.png
Attachment 7: Screenshot_2023-10-11_21-20-20_CARM_OLTF.png
Attachment 8: Screenshot_2023-10-11_21-06-21_FPMINoise.png
Attachment 9: Screenshot_2023-10-11_21-53-34_ETMXmotion_Night.png
  17895   Tue Oct 10 17:43:39 2023 MurtazaHowToComputer Scripts / Programsligocdsws - XQuartz Troubleshoot

ligocdsws (https://git.ligo.org/christopher.wipf/ligocdsws) is a docker with all the good stuff (cdutils, foton, etc) installed on it.
I hit a few roadblocks while installing it on my laptop (Macbook Pro 2019).
(Side Note: It's a large download ~5GB, install it with good internet connection)
A short summary of navigating them if they're run into.

When the docker is closed, it restores to the original configuration and clears everything except for the contents in the shared folder (/ligocdsws/shared).
Save all files you'd want to use in subsequent sessions in that folder yes


I installed XQuartz from the website using their pkg file. It did not configure correctly. Running xeyes (it displays a pair of eyes to check correct installation), I got the following error.

(base) murtaza@Murtaza ~ % xeyes
Error: Can't open display: /private/tmp/com.apple.launchd.F7ewSnErCw/org.xquartz:0

This was because the display port was set incorrectly. To check it 

(base) murtaza@Murtaza ~ % echo $DISPLAY                          

To find the correct environment variable, you open a terminal from XQuartz. (Run XQuartz->Applications->Terminal). Check the Display port here,

(base) murtaza@Murtaza ~ % echo $DISPLAY                          

This is the correct port. To set it correctly in your system environment, you can write it to your configuration file. Since I'm using zsh, my command looks like,

(base) murtaza@Murtaza ~ % echo 'export DISPLAY=:1' >> ~/.zshrc

(Christopher Wipf suggested installing XQuartz using macports instead: sudo port install quartz-wm)



Once Xquartz is working correctly, you can install ligocdsws using the instructions given on the gitlab repo. 

For users with a copy of ligocdsws installed before this elog was posted (10/10/2023), curl was not installed. The latest update has it installed. To update, you open a new terminal (outside the docker) and delete the environment. 

(base) murtaza@Murtaza ~ % colima delete 

The next time you run ligocdsws, it will download a fresh version of the packages (including curl).  

  17894   Tue Oct 10 17:15:54 2023 MurtazaUpdateSUSPost-Vertex Coil Driver Upgrade Suspension Calibration

Post the vertex coil driver upgrade, we need to make sure everything downstream is working correctly. Starting with checking for the input matrix for the vertex suspensions (MC1, MC2, MC3, BS, ITMX, ITMY, PRM, SRM), a free swing test was run
for the optics. (MC1, MC2, MC3 - 09/28/2023) (BS, ITMX, ITMY, PRM, SRM - 10/10/2023). PRM and SRM were left in misaligned states during the free swing test so the test needs to be run again for these optics.

The free swing test was done in the DOF basis (POS PIT YAW SIDE) (as opposed to kicking one coil) as the rest of the pipeline has been set up to work accordingly. This can be modified post the vent. The duration for each kick was 09/28/2023 - 600s, 10/10/2023 - 1000s respectively.

I am currently considering 1 order of magnitude of separation between the highest and the next highest peak in the spectrum to be good resolution (Given in Table) (suggestions welcome!)

The spectrum, time series for each kick, optic are attached and numbered in the table with the corresponding attachment number.

Due to the absence of a unique peak in the spectrum for ITMX, ITMY, their input matrix needs to be recalculated.

BS 12: GOOD 11: GOOD 10: GOOD
ITMY 15: BAD 14: BAD 13: BAD
ITMX 18: GOOD 17: BAD 16: BAD
Attachment 1: fs_MC3_YAW_09_28.png
Attachment 2: fs_MC3_PIT_09_28.png
Attachment 3: fs_MC3_POS_09_28.png
Attachment 4: fs_MC2_YAW_09_28.png
Attachment 5: fs_MC2_PIT_09_28.png
Attachment 6: fs_MC2_POS_09_28.png
Attachment 7: fs_MC1_YAW_09_28.png
Attachment 8: fs_MC1_PIT_09_28.png
Attachment 9: fs_MC1_POS_09_28.png
Attachment 10: fs_BS_YAW_10_10.png
Attachment 11: fs_BS_PIT_10_10.png
Attachment 12: fs_BS_POS_10_10.png
Attachment 13: fs_ITMY_YAW_10_10.png
Attachment 14: fs_ITMY_PIT_10_10.png
Attachment 15: fs_ITMY_POS_10_10.png
Attachment 16: fs_ITMX_YAW_10_10.png
Attachment 17: fs_ITMX_PIT_10_10.png
Attachment 18: fs_ITMX_POS_10_10.png
  17893   Tue Oct 10 16:04:15 2023 ranaUpdateIOOsome IMC WFS tweaks: update - WFS still look OK
Attachment 1: WFS-Controls.pdf
  17892   Tue Oct 10 14:10:11 2023 PacoConfigurationLSCETMY actuation calibration using ALSY

[Vittoria, Paco]

This work was done yesterday ~ 8 PM. After we aligned YARM and locked using POY11, Vittoria turned on the SRCL osc at 1 kHz and steadily increased the gain while looking at the BEATY demod signal. The noise floor of the BEATY was estimated to be 6.6 Hz/rtHz at 1kHz, and the line appeared with 300 counts with an average magnitude (Tavg= 25 s) of 25.5 +- 1.3 Hz. Using the approximate (overestimated) length of L=40 m and the (also overestimated) frequency of the laser f=281.9 THz, we inferred a displacement magnitude of 3.62 +0.18 - 0.37 pm at 1 kHz. This is in agreement with Yuta's recent calibration coefficient of 10.66e-9 / f^2 m/count from which we expect 3.19 pm at 1 kHz.

After this we aligned XARM and configured the interferometer to lock "electronic" FPMI but were not successful.


  • Lock FPMI, use high-BW Common mode board for CARM feedback
  • Turn on lines.
  17891   Mon Oct 9 15:17:05 2023 ranaUpdateIOOsome IMC WFS tweaks
  • with WFS off, I use MC_ALIGN screen to get erasonable power and better cenetering on mc2 QPD
  • With good alignment, I unlocked MC and aligned DC beams on WFS
  • Re-lock IMC.
  • Turn on WFS w OLD matrix.
  • Let's see how it goes Mon Oct 9 15:18:20 2023

It still works after a couple of hours. Around 6 PM I did some small alignment changes to bring the control signals closer to zero.

So my conclusion is that it wasn't a matrix issue, but just that the alignment was so off that we were out of the linear range or maybe just off the MC2 QPD. Hopefully it behaves well tonight.

Attachment 1: wfs-fb-trend.png
Attachment 2: wfs-err-trend.png
  17890   Mon Oct 9 14:10:50 2023 rana, pacoUpdateIOOIFO ALIGNED (WITH SOME ISSUES)

since the IMC alignement / rework from Sep 26, the IMC WFS has not been working. The outputs seem to be railing after a long time.

Attached is an image of the MC_TRANS QPD. You can see that after the mid Sep electronics rework, we never got the MC back to the original alignment.

We shoud NOT align the beam on there to the QPD center since that is our main MC2 pointing reference.


Attachment 1: mc2-trans-trend.png
  17889   Sat Oct 7 21:39:29 2023 PacoSummaryCalibrationFSR measurement setup

I've been meaning to attempt this method to measure the arm cavity length with negligible systematic error for calibration. I came this evening to assess the situation and make a plan.

The measurement procedure would go something like this:

  1. Lock arm cavity to PSL using POX/POY.
  2. Measure the PM to AM transfer function from the excitation at the PM (e.g. marconi FM-IN or another EOM) to the transmitted AM (Trans PD).
  3. In the presence of an error point offset, the PM to AM TF should have a global minimum at the FSR frequency which can be read with high accuracy.

The issue with this is the FSR is ~ 3.75 MHz but the trans PD at the ends are Thorlabs PD520A, with a maximum bandwidth of 250 kHz. Browsing around the PD cabinet along YARM and the PSL table I found a PD10A (150 MHz bandwidth, but 0.8 mm^2 area). I mounted it but not yet aligned anything to it at the YEND table, right behind the current TRY PD.

Another issue is the measurement itself, given that the excitation needs to happen near the PM which is near the vertex area for the PSL, but the readback is at the end (transmission PDs). I considered briefly the alternative of using the AUX lasers, and indeed we have GTRY and GTRX PDs with ~ 10 MHz bandwidth (PD100A), but the issue is we don't have EOMs for AUX lasers, so we are stuck with the ~ 200 kHz PM from the piezo resonances...

I think the best bet is to proceed with the PSL as the PM, and use PD10A or PD100A if there is one around to calibrate the arm cavity lengths and use a long BNC from a moku or agilent high freq network analyzer to the vertex PM area since we don't necessarily care about the extra delays.

Finally, I couldn't find the cds laptop and wasted some time fiddling with my own laptop and shaky network at the ends. angry

  17888   Fri Oct 6 13:51:15 2023 JCUpdateBHDPosts used for the BHD OFI

Not a fanatic of the "-02 TFP -3.3125 [ D2300352_1inch_post ]" configuration. The previous hole that comes with the original design could leave some semi-sharp edges. (Even if we ask the machinist the break them down).

Koji recommended to check the if we can modify the 6in Pedestal and avoid the issue of the hole. I went ahead and made these modifications and uploaded the new sketch to the [D2300352](https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Identifier&docid=D2300352&version=) as

I still have a couple of modifications to make such as add vent groove at the top.


Attachment 1: Screenshot_2023-10-06_153204.png
  17887   Thu Oct 5 23:32:47 2023 KojiUpdateBHDPosts used for the BHD OFI

The BHD OFI path consists of a few optical components: (Attachment 1)

  1. HWP ROtator
  2. Thin Film Polarizer (x2)
  3. Faraday Rotator
  4. HWP (fixed) Mount
  5. Beam Dump (x2)

They use custom length posts because they have different vertical sizes and also, the beam elevation on the platform is nonstandard (4.2inch).

We are going to make these posts using Newport's 4inch pedestal posts, which we already have.
The posts are machined to have the proper lengths. Additionally, we want to make venting holes and gaps to keep the gas escapting paths.

The 3D models of the posts can be found as D2300352_1inch_post.SLDPRT in the SW Vault (C:\llpdmpro\RnD\40m\BHD Platform\Beam dump) - Attachment 2
This model has four configurations that corresponds to the posts for 1/2/4/5 of the above.

Config: -01 beam dump (Attachment 3)
QTY 5 (2 + 3 spares)

The total height to be shortened to be 3.2inch.

Config: -02 Thin Film Polarizer  (Attachment 5)
QTY 3 (2 + 1 spare)
The total height to be shortened to be 3.3125inch

Config: -03 HWP Rotator  (Attachment 6)
The total height to be shortened to be 3.413inch.

Config: -04 HWP Mount  (Attachment 7)
The total height to be shortened to be 3.075inch.
The top part is made thinner (D=0.7") to fit with the recess on the mount. The height of this part is 0.15".

General Remarks:

  • The top 8-32 hole should be re-drilled and re-tapped. The depth should be ~0.5inch.
  • The upper and lower surfaces have the vent grooves. The original hole may interfere with the new top surface??? Please check. It's OK if we can mount the beam dump head on it.
  • Appropriate vent holes must be made from the side.
  • The top and bottom surfaces may need to be filed (deburred) to recover the flat contact of the top/bottom surfaces.
  • Appropriate chamfer should be applied to remove the sharp edges.
Attachment 1: Screenshot_2023-10-05_230041.png
Attachment 2: Screenshot_2023-10-05_230205.png
Attachment 3: Screenshot_2023-10-05_230441.png
Attachment 4: Screenshot_2023-10-05_230515.png
Attachment 5: Screenshot_2023-10-05_230539.png
Attachment 6: Screenshot_2023-10-05_230612.png
  17886   Thu Oct 5 13:29:58 2023 yutaUpdateSUSActuator calibrations after vertex coil driver upgrade

We calibrated actuators for the first time after the vertex coil driver upgrade.
Most of results look consistent with previous measurements thanks to "V2A" balancing, but PRM and MC2 now have about half of the actuation efficiency we used to have.
Any way, the actuation efficiencies between all the optics are now consistent with each other.

Summary of calibrations today:
AS55_Q in MICH : 1.32e9 counts/m (consistent with previous measurements)
BS     : 69.54e-9 /f^2 m/counts (about 40% higher than the previous measurement) V2A=3.0072*0.773=2.32
(sqrt(2) larger efficiency than ITMs due to 45 deg in MICH)
ITMX   : 14.73e-9 /f^2 m/counts (about 40% higher than the previous measurement) V2A=2.9966*0.218=0.653
ITMY   : 14.50e-9 /f^2 m/counts (about 40% higher than the previous measurement) V2A=3.025*0.218=0.659
PRM    : -19.00e-9 /f^2 m/counts (about 2 times less than the previous measurement) V2A=0.773
ETMX   : 12.20e-9 /f^2 m/counts (about 20% higher than the previous measurement) has x0.414
ETMY   : 10.66e-9 /f^2 m/counts (consistent with the previous measurement) has x0.48
MC2    : -6.35e-9 /f^2 m/counts in arm length (about 2 times less than the previous measurement) V2A=0.105
MC2    : 2.27e-9 /f^2 m/counts in IMC length (about 2 times less than the previous measurement) V2A=0.105
MC2    : 4.73e+4 /f^2 Hz/counts in IR laser frequuency

 - Aligned both arms (YARM ASS seems to be working. TRY ~ 1.05. XARM ASS does not. TRX ~ 0.91).
 - Misaligned ETMs, aligned MICH (MICH seems to be noisier than before...).
 - Run /opt/rtcds/caltech/c1/Git/40m/scripts/CAL/OpticalGain/getOpticalGain.py C1:LSC-ASDC_OUT C1:LSC-AS55_Q_ERR to get MICH optical gain for AS55_Q (see Attachment #1).
 - Calibrated BS, ITMX and ITMY using the method described in 40m/17752 (Attachment #2). MICH was locked with BS, ITMX and ITMY when measuring respective transfer functions.
 - Calibrated PRM using the method described in 40m/17752, using ITMY as reference (Attachment #3 and #4). PRCL was locked with PRM and ITMY when measuring respective transfer functions.
 - Calibrated ETMX, ETMY and MC2 using the method described in 40m/17679 (Attachment #5-#9).

Some notes:
 - I noticed that C1:SUS-ITMX_POS_OFFSET has an offset of 4203. Any reason for this?

 - Measured values divided by "V2A" filters (which are calculated from Old/New ratio in 40m/17860) are the following, and they are more or less the same between suspensions. GOOD!yes
BS     : 69.54e-9 /f^2 m/counts / 2.32 / sqrt(2) = 21.20 /f^2 m/counts
ITMX   : 14.73e-9 /f^2 m/counts / 0.653 = 22.56 /f^2 m/counts
ITMY   : 14.50e-9 /f^2 m/counts / 0.659
= 21.67 /f^2 m/counts
PRM    : -19.00e-9 /f^2 m/counts / 0.773
= 24.58 /f^2 m/counts
ETMX   : 12.20e-9 /f^2 m/counts / 0.414
= 29.47 /f^2 m/counts
ETMY   : 10.66e-9 /f^2 m/counts / 0.48
= 22.21 /f^2 m/counts
MC2    : 2.27e-9 /f^2 m/counts in IMC length / 0.105 = 21.62 /f^2 m/counts

Previous values:
AS55_Q in MICH : 9.2e8 counts/m (40m/17752)
BS     : 50.88e-9 /f^2 m/counts (40m/17752)
ITMX   : 9.50e-9 /f^2 m/counts (40m/17752)
ITMY   : 9.75e-9 /f^2 m/counts (40m/17752)
PRM    : -41.40e-9 /f^2 m/counts (40m/17752)
ETMX   : 10.99e-9 /f^2 m/counts (40m/17679)
ETMY   : 10.99e-9 /f^2 m/counts (40m/17679)
MC2    : -14.27e-9 /f^2 m/counts in arm length (40m/17679)
MC2    : 5.10e-9 /f^2 m/counts in IMC length (40m/17679)
MC2    : 1.06e+5 /f^2 Hz/counts in IR laser frequuency (40m/17679)

 - Find out why PRM and MC2 now has half the actuation efficiency (something related to DAC differential/single-ended 40m/17738?).
 - Check dewhitening status of MC1,2,3

Attachment 1: LSC-AS55_Q_ERR_1380565513.pdf
Attachment 2: actcalibITMBS_20231005.pdf
Attachment 3: PRMActuatorTF_20231005.pdf
Attachment 4: PRMActuatorRatio_20231005.pdf
Attachment 5: ETMXActuatorCalibration_20231005.pdf
Attachment 6: ETMYActuatorCalibration_20231005.pdf
Attachment 7: ETMActuatorCalibration_Raito_X_20231005.pdf
Attachment 8: ETMActuatorCalibration_Raito_Y_20231005.pdf
Attachment 9: ETMActuatorCalibration_Raito_MC2_20231005.pdf
  17885   Wed Oct 4 19:33:23 2023 KojiUpdateBHDThe optical fiber for the BHD/OMC assembly long enough

The optical fiber that Hiroki set up turned out that long enough for the use in the new HEPA optical bench. (Attachment 1)

The fiber was rolled and placed beneath the PSL table. The end is capped. (Attachment 2)

Attachment 1: PXL_20231005_005310288.jpg
Attachment 2: PXL_20231005_005933379.jpg
  17884   Wed Oct 4 17:28:48 2023 KojiSummaryBHDBalance Mass Layout

I went to the Solidworks model of the ITMY invac table and checked where the center of mass is.

The center of mass (COM) of the loaded items is at (+34.0mm, +8.8mm) from the center of the table. (BTW, it is above the table by 115mm). The total mass is 86.2kg.

To bring the COM at the center of the table, we need to place the balance mass(es).
An example solution is shown in the attachment.
It involves two masses (8kg and 2.5kg).
The 8kg one is fixed on the BHD platform behind AS3. The other one will be placed on the table, well away from everything.

Attachment 1: mass_layout.pdf
  17883   Wed Oct 4 10:36:03 2023 MurtazaUpdateSUSSmall Optic Suspension Simulation

The triple suspensions (mode cleaners: PRM, SRM) at the Livingston site have measured excess feedback noise in the local damping filters for the suspensions. 
This exercise is to familiarize myself with python-controls, python-foton using the SOS model and damping filters for one optic at the 40m and then work my way towards the diagnostics for the triple suspension (HSTS)

Simulation of a Small Optic Suspension:

Model: Ian provided the 3 DOF (POS, PIT, YAW) state space model built off the Malik Rakhmanov model in python. A few changes were made to it
- Appended the 'SIDE' DOF to be consistent with the current working state of the system
- Got rid of (1/s) factors in the control and observation matrix

Filters: Damping filters for ITMY were obtained using python-foton. The library is installed correctly on Pianossa, the zpk values (s-plane) for the active filters (30:0.0, Cheby, BounceRoll) were saved as a dictionary and imported on my local device (to avoid installing control, slycot libraries on Pianossa)

The impulse and step response for the open (Attachment 1) and closed loop (Attachment 2) systems are generated and attached.

TO-DO (for SOS):

- Generate the frequency response for the system
- Superimpose the open-loop and close-loop response of the system
- Migrate the notebook to ligocdsws and merge SmallOpticSuspension and GrabFotonFilters notebooks (it has a working library of crtools installed and thus foton works in there)
- Modify code to read the state of the filter (ON/OFF) and obtain the appropriate filter banks for the damping loops
- Inject white noise (e-10m) into the system and model the response 

TODO (for HSTS):

- Save the active damping filters for a triple suspension (HSTS) from Livingston
- Import a HSTS model to python
- Close the loop on the model using the damping filters

Attachment 1: Open_Loop_Suspended_Mirror.pdf
Open_Loop_Suspended_Mirror.pdf Open_Loop_Suspended_Mirror.pdf Open_Loop_Suspended_Mirror.pdf Open_Loop_Suspended_Mirror.pdf Open_Loop_Suspended_Mirror.pdf Open_Loop_Suspended_Mirror.pdf Open_Loop_Suspended_Mirror.pdf Open_Loop_Suspended_Mirror.pdf
Attachment 2: Close_Loop_Suspended_Mirror.pdf
Close_Loop_Suspended_Mirror.pdf Close_Loop_Suspended_Mirror.pdf Close_Loop_Suspended_Mirror.pdf Close_Loop_Suspended_Mirror.pdf Close_Loop_Suspended_Mirror.pdf Close_Loop_Suspended_Mirror.pdf Close_Loop_Suspended_Mirror.pdf Close_Loop_Suspended_Mirror.pdf
  17882   Mon Oct 2 17:17:46 2023 PacoSummaryDAQYEND and XEND acromag

I pulled out the YEND acromag chassis to check how a connection is made. I unplugged it and then opened it without removing any front panel connections, and then I proceeded to wire the XEND acromag chassis at the electronics bench. After the work was done, I pushed it back but I couldn't restart modbusIOC, even after running daemon-reload on c1auxey1. The ETMY watchdogs are down for now, as are the vertex and XEND ones. I tried restarting c1auxey1 but this didn't help, so maybe something was wrong when mounting the NFS? I will continue this restoration tomorrow and then replicate this at the XEND.

UPDATE Tue Oct 3 10:13:17 2023

I fixed this issue by ensuring the nfs mount was working. To do this, from c1auxey1 I ran:

sudo mount -a

and then I restarted the modbusIOC.service. Finally, I damped ETMY.

UPDATE Tue Oct 3 16:17:54 2023

[JC, Paco]

The ETMX acromag chassis wiring is complete (Attachment #1) including the optoisolator bit. JC is completing the front panel arrangement and labels and we should be good to go. I moved a binary output chassis from near the vertex rack to the XEND rack and plan to install it along with the acromag chassis to mirror the YEND rack. Finally, the next step is to correctly deploy the modbusIOC service and paying attention to recent changes, for example those in (40m/17702). Since the wiring is similar to YEND, maybe we can simply copy the db file contents.

Attachment 1: PXL_20231003_180150312.MP.jpg
  17881   Mon Oct 2 15:05:33 2023 VittoriaSummaryPSLPMC Alignment

[Rana, Vittoria]

At 3 pm, we did some PMC alignment, and the transmission value went from 665 to 680.

Also, we aligned the reflected beam.

Now the unlocked value the reflected photodiode sees is ~440 mV, and when it's locked, it sees ~21 mV. Before doing the alignment, the unlocked value was ~400 mV.


  Draft   Thu Sep 28 16:45:54 2023 MurtazaUpdate IFO ALIGNED (WITH SOME ISSUES)

[Rana, Radhika, Murtaza]

WFS Loop Debugging

- We turned on the WFS loops with very small gain (0.01) to see how the error signals behave. There is an existing template to look at the error signals in ndscope (users->Templates->ndscope->IOO->WFS->WFS-overview.yml). We observed C1:IOO-WFS2_IY_DQ stay at a constant offset as we increased the gain to 1.

- The output matrix for WFS (C1IOO_WFS_INMATRIX) was restored to the original value using burtgooey to mitigate the WFSoutMatBalancing.py change 17874.

- (TODO) WFS1 and WFS2 are slightly misaligned as seen on the C1IOO_LOCKMC screen. These need to be aligned when the IFO is unlocked so that the beam is centered on them.

- (TODO) With the PSL shutter turned off, WFS heads should show 0 reading which is not the case. This needs to be corrected for to mitigate the offset readings.

- The electronics upgrade should ideally only affect the suspensions (everything upstream should not need any changes).

- Note: The MC_TRANS error signals look very small in PIT and YAW.

  17879   Thu Sep 28 12:43:02 2023 RadhikaUpdate IFO ALIGNED (WITH SOME ISSUES)

While aligning today I realized the cavAlign step sizes and step factors had not been updated after the upgrade.

Here are the new MEDM command arguments to launch cavAlign. Only factors not equal to 1 are listed. The updates made by me are in red

Optic pair Step size Step factor
PR3-ETMY 1  
TT1-TT2 0.001  
PR2-PR3 1  
TT2-PR3 0.001 1000
PR3-ITMY 1  
SR2-AS1 1  
SR2-AS4 1 3.6
LO1-AS4 1  
PRM-PR2 1  
TT2-PRM 0.001 1000

Interesting notes:

- the factor of 3.6 for AS4 relative to SR2 is interesting - don't know where this comes from.
- LO1-AS4 step size was never updated from 0.001 to 1. I made the change.
- ITMX-ITMY step size for MICH was originally 0.0001. I've set the new step size to 0.1 to reflect this.
  17878   Thu Sep 28 11:30:13 2023 yutaUpdateSUSChecking suspension damping loop polarity conventions

To further homogenize the suspensions, we did the following changes.

 - Changed +/- 13 in SDCOIL_GAIN of SR2,LO1,LO2,AS1,AS4 to +/-1 and increased SUSSIDE_GAIN accordingly
 - PRM SDSEN_GAIN was changed from +0.2 to +1 (see 40m/17877)
 - Moved FM6 "gain_offset" of gain(0.48) to FM1 in ETMY *COIL to align with other suspensions. Also added x0.48 to SDCOIL as well, and adjusted SUSSIDE_GAIN accordingly.
 - "Half shorted" binary inputs to coil drivers for PR2,PR3,SR2,LO1,LO2,AS1,AS4 so that they are always in "Acq" mode. FM9 SimDW filters were turned on accordingly.

Before work today:

2023-09-28 17:10:19 UTC (GPS: 1379956237)
channel\optic   MC1     MC2     MC3     BS      ITMX    ITMY    PRM     SRM     ETMX    ETMY    PR2     PR3     SR2     LO1     LO2     AS1     AS4     
ULSEN_GAIN        +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00 
LLSEN_GAIN        +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00 
URSEN_GAIN        +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00 
LRSEN_GAIN        +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00 
SDSEN_GAIN        +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +0.20   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00 
ULSEN_SWSTAT      37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923 
LLSEN_SWSTAT      37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923 
URSEN_SWSTAT      37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923 
LRSEN_SWSTAT      37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923 
SDSEN_SWSTAT      37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923 
SUSPOS_GAIN     +120.00 +150.00 +100.00 +100.00 +150.00  +50.00  +28.00  +25.00 +150.00  +41.00   +8.00  +10.00  +27.00  +10.00  +10.00  +14.00  +15.00 
SUSPIT_GAIN      +60.00  +10.00  +24.00  +10.00  +14.00   +7.00   +5.00   +1.20  +15.00   +6.00   +2.00   +5.00   +6.00   +4.00   +3.00   +2.50   +3.10 
SUSYAW_GAIN      +60.00  +10.00   +8.00   +3.00  +10.00   +8.00   +4.00   +1.50  +10.00   +6.00   +2.00   +5.00   +6.00   +3.00   +3.00   +3.00   +3.00 
SUSSIDE_GAIN    +100.00 +150.00 +125.00  +10.00  +60.00  +50.00  +50.00   +7.50 +150.00 +300.00  +11.54  +20.00  +10.77   +3.08   +3.85   +6.54   +3.15 
OL_PIT_GAIN       +1.00   +1.00   +1.00   -0.05   +5.00   +3.50   +6.00  +12.68   +1.00   -1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00 
OL_YAW_GAIN       +1.00   +1.00   +1.00   +0.10   +5.00   -4.00   -8.00  -15.85   +1.00   -1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00 
ULCOIL_GAIN       +1.01   +1.07   +0.94   +1.06   -1.10   +1.06   +0.97   +1.09   -1.01   -1.00   -1.00   -1.00   -1.00   -0.94   -1.05   -0.94   -0.98 
LLCOIL_GAIN       -0.95   -0.98   -0.94   -0.98   +0.90   -1.01   -1.04   -1.00   +0.97   +0.81   +1.00   +1.00   +1.00   +0.98   +0.63   +0.99   +0.97 
URCOIL_GAIN       -0.98   -0.98   -1.04   -1.04   +0.93   -0.99   -1.04   -0.92   +1.03   +0.74   +1.00   +1.00   +1.00   +1.00   +1.34   +1.04   +0.98 
LRCOIL_GAIN       +1.06   +0.97   +1.08   +0.92   -1.07   +0.94   +0.90   +0.99   -0.99   -1.05   -1.00   -1.00   -1.00   -1.07   -0.98   -1.03   -1.07 
SDCOIL_GAIN       +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   -1.00   -1.00   -1.00   -1.00  -13.00  -13.00  -13.00  +13.00  -13.00 
ULCOIL_SWSTAT     37889   38657   37889   38657   38657   38657   38657   38657   55041   38688   38400   38400   38400   38400   38400   38400   38400 
LLCOIL_SWSTAT     37889   38657   37889   38657   38657   38657   38657   38657   38657   38688   38400   38400   38400   38400   38400   38400   38400 
URCOIL_SWSTAT     37889   38657   37889   38657   38657   38657   38657   38657   38657   38688    5632   38400   38400   38400   38400   38400   38400 
LRCOIL_SWSTAT     37889   38657   37889   38657   38657   38657   38657   38657   38657   38688   38400   38400   38400   38400   38400   38400   38400 
SDCOIL_SWSTAT     37889   38657   37889   38145   38145   38145   38145   38145   38657   38656   38144   38144   38144   38144   38144   38144   38144 

After work today:

2023-09-28 18:26:55 UTC (GPS: 1379960833)
channel\optic   MC1     MC2     MC3     BS      ITMX    ITMY    PRM     SRM     ETMX    ETMY    PR2     PR3     SR2     LO1     LO2     AS1     AS4     
ULSEN_GAIN        +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00 
LLSEN_GAIN        +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00 
URSEN_GAIN        +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00 
LRSEN_GAIN        +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00 
SDSEN_GAIN        +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00 
**SEN_SWSTAT      37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923   37923 
SUSSIDE_GAIN    +100.00 +150.00 +125.00  +10.00  +60.00  +50.00  +50.00   +7.50 +150.00 +625.00  +11.54  +20.00 +140.00  +40.00  +50.00  +85.00  +40.00 
SDCOIL_GAIN       +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   +1.00   -1.00   -1.00   -1.00   -1.00   -1.00   -1.00   -1.00   +1.00   -1.00 
ULCOIL_SWSTAT     37889   38657   37889   38657   38657   38657   38657   38657   55041   38657   38656   38656   38656   38656   38656   38656   38656 
LLCOIL_SWSTAT     37889   38657   37889   38657   38657   38657   38657   38657   38657   38657   38656   38656   38656   38656   38656   38656   38656 
URCOIL_SWSTAT     37889   38657   37889   38657   38657   38657   38657   38657   38657   38657   38656   38656   38656   38656   38656   38656   38656 
LRCOIL_SWSTAT     37889   38657   37889   38657   38657   38657   38657   38657   38657   38657   38656   38656   38656   38656   38656   38656   38656 
SDCOIL_SWSTAT     37889   38657   37889   38145   38145   38145   38145   38145   38657   38657   38144   38144   38144   38144   38144   38144   38144 

ULCOIL_STAT of ETMY being 55041 is OK. 38657+2**14 = 55041.
Script to produce these tables live in /opt/rtcds/caltech/c1/Git/40m/scripts/SUS/suspension_epics_check.py

Current coil dewhitening filter situations:

Optics Binary Inputs Run/Acq LEDs Enable/Disable LEDs Binary Outputs
MC1, MC3 lower half shorted off (Acquire mode; no dewhitening; FM9 28HzELP is off for now) all ON (Enable) not connected
MC2 lower half shorted off (Acquire mode; no dewhitening; so SimDW should be always ON) all ON not connected
SRM. PRM, ITMX, ITMY, BS lower half shorted off (Acquire mode; no dewhitening; so SimDW should be always ON) all ON not connected
ETMX lower half shorted off (Acquire mode; no dewhitening; so SimDW should be always ON) all ON not connected
LO1, LO2, AS1, AS4 lower half shorted off (Acquire mode; no dewhitening; so SimDW should be always ON) all ON DB9 cable
SR2 lower half shorted off (Acquire mode; no dewhitening; so SimDW should be always ON) all ON DB9 cable
PR2, PR3 lower half shorted off (Acquire mode; no dewhitening; so SimDW should be always ON) all ON DB9 cable
ETMY DB9 cable (BIO now works) off when SimDW is ON, ON when SimDV is off all ON DB9 cable

 - Investigate 60 Hz noise in laser frequency and check 28 Hz ELP situation for MC1,MC2,MC3
 - Fix ETMX acromag

  17877   Thu Sep 28 11:27:24 2023 RadhikaUpdateSUSPRM/SRM damping/alignment

PRM/SRM OSEM input calibration

- I realized I had not yet updated the input OSEM cts2um calibration. For PRM and SRM, I changed each cts2um filter gain from 0.36 ---> 0.0417 (factor of 8.64).

- The coil output filters (V2A) had already been updated according to new actuation calibration.

PRM damping/alignment

- As noted in the previous ELOG, PRM SDSEN gain was 0.2 instead of 1. I turned on damping filters for PRM and noticed SD motion was underdamped. I changed PRM SDSEN GAIN from 0.2 ---> 1. Final PRM damping test in Attachment 1.

- With PRM alignment restored (no PIT offset in output matrix), the PRM oplev is aligned and is recording light.

- I left PRM with a misalignment offset (damping loops on; oplev loops off).

SRM damping/alignment

- I performed a damping test of SRM with the optic alignment restored (no PIT offset in output matrix). This way the OSEMs were not saturated. In this configuration, SRM passed a damping test [Attachment 2].

- However in this configuration, no light was hitting the oplev. I tried to manually align but gave up after I saw no improvement. Which raises the question, was the SRM oplev ever (recently) aligned?

- I left SRM with a misalignment offset, but in this state the OSEMs saturate and the damping loops drive unstable motion. So SRM damping loops are off.


Attachment 1: PRM_damping_kick_2023-09-28.png
Attachment 2: SRM_damping_kick_2023-09-28.png
  17876   Wed Sep 27 21:11:36 2023 yutaUpdateSUSChecking suspension damping loop polarity conventions

[Paco, Yuta]

We checked the polarity of suspension damping loops if they follow the conventions we agreed in 40m/16898.
Suspensions are nicely homogenized nicely yes, with some exceptions (see Attachment #1).

  • ​PRM SDSEN_GAIN is 0.2, but it should be 1.
  • LO1, LO2, AS1, AS SDCOIL_GAIN is +/-13, but it should be +/- 1. (Unless there are reasons for these 13)
  • Let's make coil dewhitening to be off (in Acq mode) for all by default to homogenize (40m/17875). MC1 and MC3 might require 28Hz ELP for 60Hz noise.
  • INMAT should be normalized nicely so that SUSPOS/SIDE_IN will be um and SUSPIT/YAW_IN will be urad. (Are cnts2um in *SEN filters correct?)
  • Gain offsets in *COIL filters (e.g. V2A, x0.414) can be adjusted later to have the same actuation efficiencies between suspensions.

Note that *COIL_GAIN are now +--++ or flipped one in the order of UL/LL/UR/LR/SD.

  - Address the points raised above
  - Make a script to show current EPICs values for all suspensions to check the damping configurations.

Attachment 1: IMG_7498.JPG
  17875   Wed Sep 27 14:01:11 2023 yutaUpdateSUSWhitening/dewhitening check at Yend

[Paco, Yuta]

 We checked whitening and dewhitening situations in all the suspensions, and fixed them for ETMY.

ETMY trans QPD and ETMX trans QPD whitening:
  These QPDs have analog whitening filter of two 40:4s (LIGO-D1400415 and LIGO-D1400414). So, two of 4:40 in FM1 and FM2 of C1:SUS-ETM(Y|X)_QPDx should be always on. FM2s were off, so we turned ON today (see Attachment #1).

Fixing ETMY coil dewhitening BIO switch:
  Binary switching for ETMY coil dewhitening was not working because DB37 cable from Contec 32 BO card was not connected to the Binary Output Interface Chassis (LIGO-D1002593).
  After connecting the DB37 cable with a gender changer (we need a F to F cable), some of the switching worked but not in the correct order. Using a BD37 breakout board, we noticed that the binary switching is doing the switch in the mixed order of coil dewhitening and OSEM whitening. We modified the c1scy model so that the coil dewhitening switches Run/Acq LEDs correctly (Attachment #2 was before, and modified to Attachment #3). OSEM whitening binary switches are now terminated in c1scy model, because OSEM analog whitenings are always on (LIGO-D2100144).
  We also modified c1scx model to match with c1scy, although we don't have the acromag for Xend yet.
  Attachment #4 is the BIO status when ETMX and ETMY are in run mode (coil dewhitening on). ETM(Y|X)_BO_0_0 is for coil dewhitening, and BO_0_1 is for trans QPDs.
  Attachment #5 is the photo of LEDs correctly lit when ETMY is in run mode, after all these modifications.

Summary of Coil Driver situation for all optics:
  See, also, LIGO-D1100687

Optics Binary Inputs Run/Acq LEDs Enable/Disable LEDs Binary Outputs
MC1, MC3 lower half shorted off (Acquire mode; no dewhitening; FM9 28HzELP is off for now) all ON (Enable) not connected
MC2 lower half shorted off (Acquire mode; no dewhitening; so SimDW should be always ON) all ON not connected
SRM. PRM, ITMX, ITMY, BS lower half shorted off (Acquire mode; no dewhitening; so SimDW should be always ON) all ON not connected
ETMX lower half shorted off (Acquire mode; no dewhitening; so SimDW should be always ON) all ON not connected
LO1, LO2, AS1, AS4 all shorted all ON (Run mode; dewhitening ON; so SimDW should be always off) all ON DB9 cable
SR2 all shorted all ON (Run mode; dewhitening ON; so SimDW should be always off) all ON DB9 cable
PR2, PR3 all shorted (DB9 cable was there, but Run/Acq was off and not working, so we shorted them today) all ON (Run mode; dewhitening ON; so SimDW should be always off) all ON after shorting (with DB9 cable in Binary Inputs, ON for all coils and off for N.C. UL/LL/UR/N.C. and N.C./LR/SD/N.C.) DB9 cable
ETMY DB9 cable (BIO now works from the work described above) off when SimDW is ON, ON when SimDV is off all ON DB9 cable

  By the way, for OSEMs, analog 30:3 whitening are always ON, no matter what the BIO situations are (LIGO-D2100144). So FM1 of C1:SUS-xxxx_xxSEN should be always ON.
  Also, since the recent coil driver upgrade, the order of coil outputs in SUS_SINGLE_COIL is UL/LL/UR/LR/SD, and the signs of C1:SUS-xxxx_xxCOIL_GAIN are +--++ (or flipped one). Note that it used to be +-+-+, as the order was UL/UR/LR/LL/SD (40m/16898).

  - Check sign convensions on all the suspensions
  - Check 60 Hz noise related dewhitening situation in MC suspensions (40m/17466)
  - For LO1, LO2, AS1, AS4, PR2, PR3, SR2, make them "lower half shorted" so that analog dewhitening will be turned off similarly to other vertex suspensions.

Attachment 1: Screenshot_2023-09-27_22-35-06_QPDs.png
Attachment 2: c1scy_Screenshot_2023-09-27_13-53-28.png
Attachment 3: after_c1scy_Screenshot_2023-09-27_15-52-19.png
Attachment 4: Screenshot_2023-09-27_22-55-42_BIO.png
Attachment 5: IMG_7497.jpeg
  17874   Tue Sep 26 14:07:00 2023 MurtazaUpdate IFO ALIGNED (WITH SOME ISSUES)

[Paco, JC, Murtaza]


To fix the WFS loops, went through the following steps

With the WFS loop turned off

- We manually aligned the optics MC1, MC2 and MC3 (IOO -> C1IOO_MC_Align) to maximize transmission (MC Trans Sum -> ~13300)

- We manually aligned the QPDS for WFS1 and WFS2 to center the beam by looking at the DC signals (C1IOO_WFS_QPD). The laser was clipping on WFS2

With the WFS loop turned on

- We changed the gains of the WFS filters for all signals (1.0 -> 2.0), this led to faster conversion but clipping on C1:IOO-WFS2_YAW_OUTPUT. The gains were restored to 1.0 and thus left unchanged.

- We increased the reliefMCWFS gain by a factor of 10 by changing the arguments (Execute -> Edit this screen -> Actions -> label/cmd/args -> Arguments) (0.02 -> 0.2) 

- We ran WFSoutMatBalancing.py (17334) to calculate the new output matrix


  17873   Mon Sep 25 17:01:46 2023 MurtazaUpdate IFO ALIGNED (WITH SOME ISSUES)

[JC, Paco, Radhika, Murtaza]


1. WFS Relief
We tried to change the gain to offload the offsets in the reliefMCWFS script but it The gains might need some tuning to get it to work

2. WFS Error Signals Diverging
The error signal C1:IOO-WFS2_I_PIT_MON was staying at a constant offset from 0 using the existing output matrix (C1IOO_WFS_OUTMATRIX). We tried changing the matrix coefficients that may have caused this behavior but it led to divergence in other signals (C1:IOO-WFS1_I_PIT_MON, C1:IOO-WFS2_I_YAW_MON). THIS NEEDS TO BE FIXED

3. BS was aligned using OPLEV readouts and the damping filters were checked. No funny business for BS anymore.

4. The original IFO Align scripts used the suffix "COMM" for each optic. This was changed to "OFFSET" for all arguments by editing the IFO_ALIGN screen (left click-> Execute -> Edit this screen -> !Align -> Label/Cmd/Args)

5. The OPLEV gains for ITMY were unstable and needed some tuning. New gains: C1:SUS-ITMY_OL_PIT_GAIN (14->3.5) and C1:SUS-ITMY_OL_YAW_GAIN (-8->-4). (The upgrade should not have affected this so this could be revisited later).

6. YARM (transmission ~ 1) and XARM (transmission ~ 0.6) were locked successfully!



  17872   Mon Sep 25 15:32:57 2023 JCUpdateIOOIMC Alignment After C1Sus2 Crash This Morning

[Paco, Murtaza, JC]

Fixed C1SUS2 Crash from this morning

What we did:
  - Attempt to restart only C1SUS2
  - Restart All Machines and Burt Restored to Friday @ 7:19 pm


Entering this morning, We were unsure why we were having issues aligning and come to find out that C1SUS2 crashed. Paco attempted to restore by restarted the machine individually and restoring, while this did turn all the machines green on the CDS.MEDM Screen, it did not resolve the issue. So moving forward, please keep in mind that EVEN IF ALL MACHINES SHOW GREEN, OPTICS MAY STILL NOT BE DAMPING. 

Next we continued to restart and reboot the old fashioned way.

I attempted to use the ./restartAllModels.sh script in the "/opt/rtcds/caltech/c1/Git/40m/scripts/cds" directory, but there was an error and the message I got said something along the lines of "Restart medm screen and try again". This was weird and all of the machines were already shutdown. So, to bring them back up, I used the ./startAllModels.sh script. When starting up, i was prompted to provide a burtrestore directory, and I inputted /opt/rtcds/caltech/c1/burt/autoburt/snapshots/2023/Sep/22/20:19.


This worked out and IMC came back to nominal alignment. The primary issue we seem to be coming across now is that C1:IOO-WFS2_PIT_OUTPUT is increasing at a steady rate and this is disrupting our alignment.

  17871   Fri Sep 22 19:38:06 2023 MurtazaSummaryElectronicsVertex Electronics CDS Update


[Koji, Radhika, Murtaza]

Connector on the BS Chamber that feeds to PRM UL/LL/UR coils (PRM 1 in Attachment 1) has pin 5 shorted to pin 1 inside the chamber angry
- To resolve this, a DB25 connector was recycled from the old coil drivers
- pin 5 was isolated by cutting (green cable on the DB25 connector)
- The connector was attached between the chamber and the cable that runs through to the rack (Attachment 1)
- The connector was labelled (Attachment 2)

The PD outputs were read on the PRM SATAMP (Pins 1-4, Pin 5 (Ground))
Pin 1 ~ 5.2V
Pin 2 ~ 5.3V
Pin 3 ~ 6.7V

Pin 4 ~ 0V (Blank Pin)

No need to apply an external bias to Pin 5!

Can be fixed during the next vent!

Attachment 1: IMG_9203.jpg
Attachment 2: IMG_9202.jpg
  17870   Fri Sep 22 19:31:24 2023 KojiUpdateSUSFixed IMC/IFO alignment screens

Fixed IMC/IFO alignment screens

Attachment 1: Screenshot_2023-09-23_02-28-42.png
Attachment 2: Screenshot_2023-09-23_02-28-52.png
  17869   Fri Sep 22 19:05:19 2023 KojiUpdateGeneralPower Outage Sept 21, 2023 ~9AM

Pumping configuration changed. Now TP2 is backing TP1 and TP3 is pumping annuli.


Attachment 1: Screenshot_2023-09-23_01-52-36.png
  17868   Fri Sep 22 18:26:08 2023 RadhikaSummaryElectronicsVertex Electronics CDS Update

[Koji, Radhika, Murtaza]

All upgraded suspensions have reasonable OSEM readings! Ready for damping tests and alignment next week.

We fixed PRM OSEM reading by isolating pin5 of the first DB25 [17871]. This makes the PRM UL unbiased by the PD seems to be receiving some light.

The PRM/BS/ITMX/ITMY SATAMP adapter was removed and the front-end pins were checked for shorting. Indeed, a short was found in the SIDE1-4 ribbon cable inside the sat-amp adapter, from the wires being compressed to one side of the dsub-ribbon adapter at the input joint [Attachment 1]. We reclamped the ribbon and verified there was no shorting and that the pins were properly aligned [Attachment 2]. This means PRM/BS and ITMX/ITMY SIDE signals should no longer be cross coupled.

All OSEM counts looked good after these fixes. Only a few ITMY OSEMS looked low, but Koji checked both PDMON voltages for ITMY, and we confirmed with calibration that the OSEM counts were reasonable.

Attachment 1: PXL_20230923_003545536.jpg
Attachment 2: PXL_20230923_005555079.jpg
  17867   Fri Sep 22 16:20:25 2023 RadhikaSummaryElectronicsVertex Electronics CDS Update

Today we tried to debug the unreasonable OSEM readings (see previous ELOG)

PRM process

Starting state: PRM face + side values bogus (~0)

1. Somehow through retightening connections, PRM LR+SD counts looked reasonable (and positive). Yay!

2. Toggled on and off the PRM SATAMP; removed Ch1-4 and Ch5-8 PRM inputs

    - Result: BS SD becomes negative when PRM SATAMP is on and Ch 5-8 cable is connected.

2. We disconnected the PRM SATAMP and plugged the PRM inputs into the SRM SATAMP. The SRM SATAMP output was routed to the PRM input on the SATAMP adapter.

    - Result: PRM UL/UR/LL readings still 0.

                 BS SD still negative when SRM SATAMP is turned on and Ch 5-8 from PRM are connected.

                   ---> SRM SATAMP gives same results as PRM SATAMP; PRM SATAMP likely not faulty.

3. Replaced PRM chamber connections with satellite test box for channels 1-4.

    - Result: reasonable PRM UL/UR/LL readings ---> Pin 5 shorting on chamber side is causing issues with Ch1-4.

ITMX - ITMY process

Starting state: ITMX SD counts negative, ITMY SD counts negative (depends on ITMX connection)
To test ITMX (SD negative since change), ITMY (SD negative dependent on ITMX)


 We first switched [ITMX, ITMY]  in the following sequence to get the following results (F = average face values, S = side value)(0 = OFF, 1 = ON)

- [0,0] -> ITMX[F,S] = [300, -5000] ITMY[F,S] = [0, -800]

- [1,0] -> ITMX[F,S] = [~, ~] ITMY[F,S] = [1000, -3000]

- [0,1] -> ITMX[F,S] = [-30, -3000] ITMY[F,S] = [~, ~]

- [1,1] -> ITMX[F,S] = [15000, -10000] ITMY[F,S] = [10000, -3000]


A separate test was done to test ITMX-ITMY coupling on ITMY-side






To check if ITMX was faulty from the chamber end for the SIDE DOF, the satellite test box was used for CH 5-8



For the final sanity check for the effect of ITMX on ITMY side sign, we swapped the ITMX and SRM SAT AMPS ({front -> PD OUT 1, 2}, {back -> Ch 1-4, Ch 5-8})




PRM Ch1-4 shorting issue on chamber side (UL/UR/LL)

BS/ITMY/ITMX SD <0 all seem to be caused by SATAMP adapter or downsteam in ADC2


Attachment 1: IMG_9200.jpg
Attachment 2: IMG_9201.jpg
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