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  40m Log, Page 344 of 344  Not logged in ELOG logo
ID Date Author Typeup Category Subject
  17304   Wed Nov 23 16:12:00 2022 TegaUpdateCDSI/O chassis parts inventory II

[Tega, JC]

We picked up the following I/O chassis components from Downs CDS testing lab:

Components Quantity
I/O chassis timing interface (missing aLIGO Duotone to IO interface adapter board) 1
Digital I/O PCI Express card 16ch/16ch 1
Adnaco PCI Express Gen 2 Extension System 1
PCIe x4 host interface board 6
OSS expansion Link board x4 1
OSS expansion Link board x4/x8 Gen2 3
aLIGO 16-Bit DAC Adapter board 1
aLIGO 18-Bit DAC Adapter board 12
GSC PMC-PCI adapter board 11
GSC PCIe-PMC adapter board 2
Avago LC transceiver (HFBR-57E0PZ) 9
  17305   Wed Nov 23 16:34:33 2022 KojiUpdateCDSNew donatella testing

Let's use this entry to list of the test results of new donatella.

  • Firefox - OK (typing elog now)
  • sitemap - OK
  • Diaggui (DTT) looks working fine for the current and past data
  • Dataviewer looks working fine for the current and past (slow/fast) data
  • ndscope - fine
  • foton - works fine
  • burtgooey - ?
  17306   Wed Nov 23 17:12:34 2022 RadhikaUpdateALSXARM green laser lock debugging

I tested the mixer by feeding it a 300 kHz signal sourced from a Moku:Go. I kept the LO input the same - 231.25 kHz from the signal generator. The mixer output was a ~70 kHz waveform as expected, so demodulation is not the issue in green locking.

Next I'll align the arm cavities with IR and check to see if the green REFL signal looks as expected. If not, we'll have to invesitage the REFL PD. If the signal looks fine, and we now know it's being properly demodulated, the issue must lie further downstream.

  17307   Wed Nov 23 17:21:44 2022 JCUpdateVACInterlocks may have been tripped due to N2 pressure loss

[Paco, JC]

While changing out one of the N2 tanks today, one of the fitting stripped. This caused a major loss of pressure. I replaced one fitting then realized there was a second leak around the area of the gauge. Paco and I changed this and everything should be back up and running. Thhe interlocks may have been tripped  within the last 2 hours.


  17308   Wed Nov 23 17:28:39 2022 YehonathanUpdateBHDSome more calculations

Fields at the BHD BS. More on this later.

  17310   Thu Nov 24 11:23:35 2022 AnchalUpdateSUSLow noise state

I've turned off HEPA fan and all lights at
PST: 2022-11-24 11:23:59.509949 PST
UTC: 2022-11-24 19:23:59.509949 UTC
GPS: 1353353057.509949

c1ioo model has been updated to acquire C1:IOO-MC2_TRANS_PIT_OUT  and C1:IOO-MC2_TRANS_YAW_OUT at 512 Hz rate.

I'll update when I turn the HEPA on again. I plan to turn it on for a few hours everyday to keep the PSL enclosure clean.

Turned on HEPA again at:

PST: 2022-11-25 12:14:34.848054 PST
UTC: 2022-11-25 20:14:34.848054 UTC
GPS: 1353442492.848054

However this was probably not a low noise state due to vacuum disruption mentioned here.

  17311   Thu Nov 24 15:37:45 2022 AnchalUpdateASCIMC WFS output matrix diagonalization effort

I tried following the steps and the method I was using converged to same output matrix upto 2 decimal points but there is still left over cross coupling as you can see in Attachment 1. With the new output matrix, WFS loop can be turned on with full overall gain of 1.


  • I switched off +20dB FM2 on C1IOO-WFS1_PIT and increased gain C1:IOO-WFS1_PIT_GAIN from 0.1 to 1 to be uniform with other filters.
  • Output matrix change:
    • Old matrix:
      -2.   4.8 -7.3
       3.6  3.5 -2. 
       2.   1.  -6.8
    • New Matrix:
      3.44  4.22 -7.29
      0.75  0.92 -1.59
      3.41  4.16 -7.21
  • I think the main change that allowed the WFS loop to become stable was the 0,0 element sign change.


  • I made overall gain C1:IOO-WFS_GAIN 0
  • Switched of (0:0.8) FM3 on PIT filter modules (IOO-WFS1_PIT, IOO-WFS2_PIT, IOO-MC2_TRANS_PIT)
  • Changed ramp time to 2 seconds on all these modules
  • Used offset of 10000 for WFS2 and MC2_TRANS, and 30000 for WFS1 (for some reason, response to WFS1 step was much lower than others)
  • Measured the following sensor channels
  • First I took 30s average of these channels, then applied the offsets in the three modules one by one and recorded steps in each sensor.
  • Measured step from reference value taken before, and normalized each step to the DOF that was actually stepped to get a matrix.
  • Inverted this matrix and multiplied with existing output matrix. Made sure column norm1 is same as before and column signs are same as before.
  • Repeated a few times.

Note: The standard deviation on the averages was very high even after averaging for 30s. This data should be averaged after low passing high frequencies but I couldn't find the filter module medm screens for these signals, so I just proceeded with simple averaging of full rate signal using cdsultis avg command.

Fri Nov 25 12:46:31 2022

The WFS loop are unstable again. This could be due to the matrix balancing done while vacuum was disrupted. The above matrix does not work anymore.

  17312   Fri Nov 25 12:15:46 2022 AnchalUpdateVACVacuum Gate valves restored

I came today to find that PSL shutter was closed. I orginially thought some shimmer obersvations are underway in the quiet state. But that was not the case. When I tried to open the shutter, it closed back again indicating a hard compliance condition making it close. This normally happens when vacuum level is not sufficient, so I opened the vacuum screena dn indeed all gate valves were closed. This most probably happend during this interlock trip. So the main volume was just slowly leaking and reached to milli torr level today.

Lesson for future: Always check vacuum status when interlock trips.

[Paco, Anchal]

Paco came by to help. We went to asia (the Asus laptop at vacuum workstation) but could not open the medm or find the nfs mounted files. The chiara change did something and nfs mounted directories are not available on asia of c1vac. We rebooted asia and the nfs mount was working again. We can't simply restart c1vac because it runs acromag channels for vacuum system and needs to be done more carefully, a task for Monday.

After restarting asia, we opened the the vacuum control medm screen and followed the vaccum pump down instructions (mainly opening of the gate vales as the pumps were already on). Point to keep in mind, rule of thumb, do not open valve between a turbo pump and a volume if the pressure differential is more than 3 orders of magnitude. Saving turbo pumps is the priority.. Now the main volume is pumping down.

  17313   Fri Nov 25 15:35:23 2022 AnchalUpdateSUSLow noise state

Turned off HEPA at:

PST: 2022-11-25 15:34:55.683645 PST
UTC: 2022-11-25 23:34:55.683645 UTC
GPS: 1353454513.683645

Turned on HEPA back at:

PST: 2022-11-28 11:14:31.310453 PST
UTC: 2022-11-28 19:14:31.310453 UTC
GPS: 1353698089.310453

  17314   Sun Nov 27 15:30:22 2022 ChrisUpdateOptimal ControlIMC alignment controller testing

Five more mode cleaner alignment controllers were tested this morning (remotely). These were designed to run in tandem with the standard controller, instead of supplanting it. Before the test, c1ioo was burt restored back to the settings of the previous test on Oct 28, and in MC TRANS PIT/YAW filter banks the 80 dB gain filters were disengaged and outputs were enabled. Subsequently, all settings were returned to the original values. Each test consisted of five minutes with pitch alignment uncontrolled, five minutes with the standard controller only, and twenty minutes with both controllers enabled. GPS times for each phase of testing are the following:

  • musgo
    • OL start 1353602764
    • CL start 1353603074
    • policy start 1353603410
  • musgo_ghost
    • OL start 1353604697
    • CL start 1353605007
    • policy start 1353605355
  • musgo_stumble
    • OL start 1353606574
    • CL start 1353606884
    • policy start 1353607229
  • musgo_goldfish
    • OL start 1353608446
    • CL start 1353608756
    • policy start 1353609099
  • musgo_late
    • OL start 1353610321
    • CL start 1353610631
    • policy start 1353610971
  17315   Mon Nov 28 11:15:23 2022 AnchalUpdateCDSFront ends DAC Kill (DK) got activated; restored FEs

[Anchal, Paco, Yehonathan, JC]

Last night at 9:15 pm PST (Nov 27th, 2022) some kind of disruption happened to FEs. See attachment 1 to see the changes in FE state words of the IOP models. on c1lsc, c1sus and c1scex, change of 140 happend, that's 2nd, 3rd and 7th bit of the FE word was flipped, which I think is the TIM, ADC and DAC KILL (DK). When we came in morning, IMC suspensions were undamped and not responsive to coil kicks, vertex suspensions the same case, ETMX also same. The c1sus2 modelw as all in red.

To fix this, we restarted all rtcds models on all FEs by sshing into the computers and doing:

rtcds restart --all

Then we burt restored all models to 27th Nov, 3:19 am point doing following on rossa:

~>cd /opt/rtcds/caltech/c1/Git/40m/scripts/cds
cds (main)>./burtRestoreAndResetSUS.sh /opt/rtcds/caltech/c1/burt/autoburt/snapshots/2022/Nov/27/03:19

Note: this issue was previously seen when fb1 was restarted without shutting down the FEs, and once when the martian switch was disrupted while FE models were running.

I'm not sure why this happened this time, what caused it at 9:15 pm yesterday, and why only c1lsc, c1sus and c1iscex models went to DAC KILL state. This disruption should be investigated by cds upgrade team.

  17316   Mon Nov 28 11:21:25 2022 JCUpdatePSLPMC input beam alignment

C1:PSL-PMC_PMCTRANSPD was increased from 0.72 to 0.731

ELOG V3.1.3-