Late entry for yesteday's maintenance

WP13675 CRS PROC

Jim, Arnaud, Dave:

Two sets of changes were made to h1crsproc. The first was separating the VEL and THETA filter-modules, this did not require a DAQ restart. The second was reversing this change, adding filter-modules and math parts. This did require a DAQ change

We took the opportunity to move all of h1crsproc's files to the new userapps/crs subsystem. Prior to this only the crs/h1/models/h1crsproc.mdl was in this area. Files moved are:

crs/common/models/crs_block.mdl

crs/h1/burtfiles/h1crsproc_safe.snap

crs/h1/filterfiles/H1CRSPROC.txt

TJ moved all the the CRS Guardian code

crs/common/guardian/CRS_HAM3.py

crs/common/guardian/CRS_LASER.py *

crs/common/guardian/crs_stat_main.py

All the appropriate symbolic links to these files were made.

* - A minor change was made by TJ to make this truely common, a hardcoded IFO=H1 was removed.

There were actually 3 restarts of h1crsproc. The second was because I had forgotten to move crs_block.mdl to the new crs/common/models/ directory, so a new rev-update was needed to set the new path in the rev lock JSON file.

Adding CRS_LASER Guardian node to DAQ

Dave:

The new CRS_LASER was added to H1EPICS_GRD.ini. DAQ and EDC restart was required

Beckhoff Restart To Add LVEA Cheta Chassis

Daniel:

Daniel restarted the Slow Controls system, adding 12 units to DEV1 to readout the Y Arm Cheta Chassis. No DAQ restart was required. The CDS overview was updated with the new slave counts.

DAQ Restart

Jonathan, Erik, Dave:

The DAQ was restarted for the new h1crsproc model and adding CRS_LASER to EDC. 

The 0-leg was restarted first, with the EDC being restarted immediately afterwards. As was seen before, both FW0 and FW2 crashed and required manual restarting. We strongly think the EDC restart is causing this problem, investigation continues.

The 1-leg was restarted last with no crash of FW1 (and no EDC restart).

TITLE: 10/07 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 9mph Gusts, 7mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.15 μm/s 
SHIFT SUMMARY:
Mostly a quiet night. 
Comissioners pushed forward on making it easier to lock. 
Lockloss from the IMC which went into fault a few times near 1:50 UTC.  
IMC is now relocked.

SR3 Heater turned  Off at 155 UTC. 
ISC_Lock set to down for the night.

I locked us in PRMI and checked the POP X phasing (PRC1 sensor in PRMI). I drove a PRCL line and phased POP X to put the signal in I phase. Screenshots attached with SDF.

Then, I moved PRM and watched the buildups and POP X I signals. I saw that the signals crossed zero as expected. I engaged PRC1 and the loops converged and buildups maximized. As a final check, I also ran the MICH loop and saw that both loops converged.

Yesterday, I rephased all the WFS using the X arm IR, including some poor phasing in the AS 45 WFS segments, 92179. I rechecked the response of MICH in the AS B RF45 Q signals in DRMI lock, and it looks great, signals cross zero and maximize the buildups. Therefore, we can use the same MICH sensing matrix in DRMI as in O4.

However, when I went to engage the MICH loop, we had a lockloss so I probably have a sign wrong somewhere. I will check up tomorrow.

Use MICH and PRMI are now both TRUE in PRMI. All loops are still FALSE in DRMI, but I am optimistic that with the proper phasing, we can close most of them at the next opportunity. Guardians loaded. Note, this means PRMI ASC can run without any operator intervention.

Unrelated, we had a lockloss due to the IMC dropping out (but not the JAC!), don't know why. Tagging IOO for FYI.

Looks like the spot position on PR2 is about 0.3 mm above center in pitch and 0.5 mm to the left of center if facing optic HR side. This is different than what Louis measured a few weeks ago in alog 91701 and also different from the beam spot in O4.

I locked on PRMI and injected into pitch and yaw on PR2 while adjusting the A2L gain on M3. I looked for the moment when the transfer function sign flipped as indication that I had reached a minima. Screenshots attached. I determined the following gains minimize the pitch/yaw coupling to PRCL:

P2L: -0.2, Y2L: -0.3.

Following the calculation I used here, I measured the numbers reported above. The directions are based off of comments from a script by Jenne:

"# Y2L signs mean that if you are viewing the optic from above looking down on the optic, with forward = HR face of optic and backward = AR side of optic, then +Y2L gains mean beam is on the left of center. -Y2L gains mean the beam is to the right of center.

FAMIS 85074 H1 ISI CPS Noise Spectra Check - Weekly

Sheila, Louis, Elenna, Daniel

Between maintence day and mode hopping troubles, we did some troubleshooting of ALS/TR CARM handoff today.  

• Based on Daniel’s suggestion we checked the IMC OLG.  We have nearly the same settings as described in 89438, (5dB IN1 gain both times, 6dB fast gain in March, 5dB fast gain now)  but the ugf is 65 kHz now compared to 38kHz in March, so the gain is nearly doubled for reasons that we don’t understand. (instructions for using SR785: 76751 ) We turned the IMC servo IN1 gain to 1 (reduced from 5dB), and Elenna remeasured, the ugf is now 38kHz (link plot).  I edited the IMC_REFL1 gain in lscparams.  The UGF is now 38 kHz. 
• We measured the MCL crossover again, (without the gain reduction we were doing yesterday). It is now closer to the reference, which makes sense with the lower IMC gain. (screenshot)
• We measured the ALS COMM OLG by injecting into the common mode board (plot), this shows a ugf just barely above the MCL crossover. For comparison we looked at figure 5.23 in  Staley Thesis, this OLG was then 5.3kHz.  We changed the H1:LSC-REFL_SERVO_IN2GAIN from 17dB to 27dB, and remeasured (add plot) (this gain increase is not added to the guardian).  
• Elenna and I measured the COMM PLL OLG, it is around 8kHz (photo).  Comparing this to figure 5.15 in Alexa’s thesis, the gain is very low.  We found an alog from Stefan in 2018, 44150 where this was lowered.  It seems like this is probably OK. 

The gain increase didn't allow the TR_CARM handoff to go smoothly.  

No new damage. First image is EX, second image is EY. The central panel at EY that tore it's gromets out shortly after install doesn't show any new damage, but the 4th, 5th and 6th wire from the bottom are all completely torn away from their gromets, should probably start looking at replacing that panel. But this is not new. Third image is a little difficult to see, but it shows these middle 3 wires not connected to the pannel if you zoom in. And a lot of raven poop, birds like this fence.

TITLE: 10/06 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 8mph Gusts, 5mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.15 μm/s 
QUICK SUMMARY:

H1 is currently Acquiring PRMI.
The Comissioning team is troubleshooting TR_CARM issues. 

Jennie W, Marc

This morning I shorted the inputs of pins 5,6,7,8,18,19,20,21 on the input of the SPI AA interface chassis located on SEI-C2 in slot 27.  I looked at the dark noise to determine if it was the AA chassis causing the QPD B noise problems.

The noise on segment 4 looks low under this configuration (yellow dotted line) , whereas when everything is plugged in again segment 4 has elevated dark noise as we saw last week (pink solid line).

Following this the conclusion was that the problem is with the TIA chassis.

Marc and I pulled this chassis and he looked at the output noise of each cathode/anode output on the SR785.

Comparing all 8 differential channel outputs on this chassis, they all stabilised at -48dBVpeak resolution whereas segment 4 stablised at -40dBVpeak, indicating it had excess noise relative to the other channels. In this case 'stabilised' means the measurement was not saturating the signal analyzer.

He then replaced the op-amps U1, U5 and U3 in turn and no difference was observed in the output noise spectra. Once the U4 op-amp was replaced the SR785 stopped saturating.

Looking at its spectra it looks like this op-amp slowly went bad starting somewhere around the 1st September (black dotted line) and was much worse by 24th September(green solid line).

The measurement from after the op-amp was replaced (light blue solid line) shows the problem has been fixed.

Also measured the other 3 segments before (first three traces) and after (last three traces) this change to check nothing was broken in the process of this fix and to show the baseline dark noise we expect.

J. Kissel

As we explore the relationship between HAM3 - HAM2 differential motion with the SPI, it's forcing us to re-understand some ISI fundamentals. Brian made claims that we *shouldn't* use the ISI super sensors as metrics for the real displacement of the platform in LHO:92129, and points us to some math in T2500279. I wanted to back up the math with some plots of platform motion to help better visualize the math.

You can find plots of the current blend filters in use, in their dimensionless comparable form, from LHO:70527.
- the X/Y blend frequency is 0.18 [Hz] with broad gain peaking of around 1.5x to 2x from 0.03 - 0.6 [Hz].
- the RX/RY blend frequency is 0.375 [Hz] with more focused gain peaking of 4x from 0.1 to 1 [Hz].

Let's start with RX, since that's a relatively simple feedback loop, with no sensor correction complicating the math.
(RX-1) RX ASD (Blend Inputs vs. Blend Outputs vs. Super Sensor)
    - The input to the blend filters are shown in SOLID light blue (CPS) and green (GS13), compared with their sensor noise scaled to the RX degree of freedom (same color, just in dot-dot line style). Above ~1 Hz, the CPS is limited by its sensor noise, but also arguably below 0.1 Hz. Below 0.15 Hz, the GS13 is limited by its sensor noise. This implies that 
    - As we apply the blend filters to those input signals, we see what Brian describes in Section 2 of his document:
        . There's a hefty amount of gain peaking between 0.1 and 1 Hz [Hz] from the complementary blends, reporting a factor of ~4x more motion than at the input.
        . The CPS output is virtually identical in amplitude to the GS13 output up to 10 Hz.
        . The sum of the two blended outputs is "essentially zero" -- this is what we strive to understand.
    - There two channels, H1:ISI-HAM2_BLND_RX_FADE_OUT and then H1:ISI-HAM2_BLND_SUPS_RX -- test points in series just after the sum -- and just downstream's H1:ISI-HAM2_ISO_RX_IN1 that are equivalent and identical. 
    These two test points being identical to the ISO input is only true for DOFs where there's no input from the SUSINF external "sensor correction," either SUS offloading or CPS DIFF or SPI, as is true for the RX DOF -- knowing this will become important for DOFs that employ, e.g. CPS DIFF like the X DOF. I show the SUPS_RX and ISO_RX_IN1 channels here just confirm that there's nothing wild or crazy going on like "the signal changes as you exit up and out of a level in the simulink model," and to show that there's no external input from SUSINF. 

(RX-2) RX TF COH (Blend Outputs vs. Super Sensor)
    - This shows the linear coherence between each output to the blends and the super sensor.
    - assertion The CPS output's coherence is only non-zero where the CPS are actually measuring real platform motion where that signal appears above the sensor noise, between 0.1 and ~1 Hz.
    - The coherence of the GS13 output matches the coherence of the CPS below 10 Hz. assertion That implies that the GS13s are measuring the exact same thing as the CPS in this frequency region, whether it be real platform motion, or CPS sensor noise * the blend CPS filter.
     
(RX-3) RX TF PHA(Blend Outputs vs. Super Sensor)
    - This shows the (unwrapped) phase of the TF between the CPS blended output and the GS13 blended output w.r.t. the super sensor.
    - At least below ~3 Hz [Hz] it's obvious that the blended output of the CPS is exactly 180 [deg] out of phase with the blended output of the GS13
        Spot check of RX TF Phase at 0.5 [Hz]
            DISP OUT / SS       = 529.8 [deg] 
            INERT OUT / SS      = 349.8 [deg] 
            Difference          = 180 [deg]
      One can only trust the spot check at most frequencies if the blend filters are truly complementary. If they're not, then you've gotta be conscious of the "deviation from complementary" in the comparison. This will become important for DOFs where we push hard on the performance, like the X DOF.
    - Thus, the two signals, measuring exactly the same thing with the same amplitude below ~10 Hz, and when added together, given their phase relationship, you get a super sensor signal that's "essentially zero."

(RX-4) RX TF MAG (Blend Outputs vs. Super Sensor)
    - This shows magnitude of the TF between the CPS blended output and the GS13 blended output w.r.t. the super sensor.
    - Again, below ~10 [Hz], the GS13 and CPS blended outputs has the same transfer function magntiude w.r.t. the super sensor.
    - This -- especially is essentially a measure of the loop suppression
    - assertion where the TF is incoherent, the TF magnitudes loop suppression is reporting that the platform motion is dominated by suppressing sensor noise. In the case of the GS13s, its an independent measure of this loop-suppressed CPS noise that's dominating the platform motion.