Jennie W, Sheila

Summary: We need to rerun this test with slightly different starting QPD offsets and a different amplitude to get a meaningful measurement of how the optical gain would be affected by changing the OMC alignment.

I started an injection into the OMC ASC loops (which feed back to the OMC and the OM3 pitch and yaw to keep the beams centred to specific offsets on OMC QPD A and B.

With this we can raster the OMC alignment and find which QPD offsets allow us to maximise optical gain.

The injection started at about 20:30 UTC while no squeezing was injected.

I used this template at /ligo/home/jennifer.wright/Documents/OMC_Alignment/20240419_OMC_Alignment_EXC.xml with amplitudes of 3 counts in all four degrees of freedom.

Within one cycle the OMC suspension saturated.

Why did we saturate with an injection amplitude of 3 as this ran the last time we did this test without any saturations?

Decreased amplitude to 1 to run it without saturating the OMC suspension.

Restarted at 20:39:07 UTC roughly.

Stopped injecting after 21:06:00 UTC.

Results inconclusive as changing the QPD in offset does not seem to change the noise injected around the calibration line between 410 to 411 Hz, so maybe we need to have higher injection amplitudes but start raster from different QPD offset set points so we don't staurate the suspension.

Looking at ndscope of the channels when they saturated.

OMC T2 and T3 saturated (this is an18 bit DAC). This is OMC pitch degree of freedom, which corresponds to Y direction in the OMC ASC loop basis.

Looking at the top left plot the POS Y DOF seems to correspond to the time of saturation and is the highest Y channel so we want to put in a +0.5 offset to this before the next time we run this raster to bring the input to the POS Y loop down in magnitude.

TITLE: 05/29 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 145Mpc
INCOMING OPERATOR: Corey
SHIFT SUMMARY:

IFO is in NLN since 17:45 UTC

IFO States for the day has been:

14:25 UTC: OBSERVING

14:45 UTC: Lockloss - after initial alignment, we went into planned comissioning from 16:00 UTC to 19:00 UTC. IFO stayed in down during this time for comissioning tasks. After these, we began to lock again.

17:45 UTC: Reached NLN and went into COMISSIONING

19:11 UTC: OBSERVING after comissioning tasks wrapped up

20:30 UTC: COMMISSIONING impromptu comissioning time coinciding with LLO since neither site had a fully locked IFO during the original alotted time. An hour of comissioning time was agreed upon.

21:34 UTC: OBSERVING

23:30 UTC: Shift End - OBSERVING

LOG:

TITLE: 05/29 Eve Shift: 2300-0800 UTC (1600-0100 PST), all times posted in UTC
STATE of H1: Observing at 148Mpc
OUTGOING OPERATOR: Ibrahim
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 18mph Gusts, 12mph 5min avg
    Primary useism: 0.06 μm/s
    Secondary useism: 0.09 μm/s
QUICK SUMMARY:

H1's been locked almost 5.5hrs and seem a little calmer than yesterday at this time, althought we've had some gusts approaching 30mph.  No items to hand over from Ibrahim for locking tonight (other than possibly proactively run an Initial Alignment if there are ALS or DRMI/PRMI issues

FAMIS 26304, last checked in alog77997

Only notable change was yesterday, where the new fan bearing on CS fan 6 looks to have lowered the noise picked up by the vibrometer.

Sheila, Camilla 

Checking SQZ:

• Single bounce ITMX, OM centering loops on and frozen (turn off inputs)
• Increased SEED injected power from 0.2mW to 76mW (same as April 16th 19:19UTC as in 77518 and 77518 plot)
• SQZ Manager LOCKED SEED DITHER
• ALIGN SRM, misaligned ITMs
• Previously injecting 1.28mW into HAM6 (OPO_IR_PD_LF with BeamDiv closed), now 1.25mW to 1.29mW, so similar power to before. 
• Started with ~360 on AS_C NSUM
• Kept centered on AS_C with ZM4 while moving ZM5 to increase power on AS_C.
• Power was fluctuating a lot and it seems like we were mainly on a plateau.
• Accepted new alignments (scattering in IFO will tell us if they are better or worse, hard to tell if AS_C power really increased), attached in two sdfs, mainly pitch move then yaw.
• Got peaks of 384 on AS_C_SUM, average was 370 (want 380). Still loosing 2-3% from what’s expected. 
• Similar power on AS_A and AS_B ~75.
• Plot attached. 

Checking IFO:

• Single bounce ITMX 10W in, previously had 762e-2 on AS_C_NSUM. Today had 750e-2. 
• With similar power into IMC 9.60W today, 9.61W prevoiulsy.
• Sheila checked the alignment sliders, we are ~15urad off in SR2 PIT witness channel. Everything else looks good  (DC centering not on at time). Plot attached.
• Didn't change IFO alignment, started locking. 

Last night and today we are in a different spot through the OFI.  See Sheila's alog 78096 for the move that was made. 

Overall, SR2 and SRM yaw are much closer to center in this position, however SRM pitch is farther from center.  I did a quick double check of the SRM pit, and indeed this is where it wants to be.

The previous spots (with the previous SR3 alignment) are recorded in alog 77443.

Attached are the saved SDF diffs for both Observe and Safe snap files.

FAMIS 25993, last checked in alog77948

No appreciable difference that I can see compared to last check.

Sheila added a new boost in DHARD to the guardian, and we relocked with it successfully, so I have accepted the SDF diff in Observe.

Wed May 29 10:15:30 2024 INFO: Fill completed in 15min 25secs

Gerardo confirmed a good fill curbside.

FAMIS 28354, last checked in alog77843

Late alog for the in-lock charge measurement taken last Tuesday before maintenance (May 21st). There was no measurement taken this week (IFO was unlocked before maintenance this Tuesday).

J. Kissel 

Remeasured the same remote, DAC-driven measurement of the whole OMC DCPD sensing chain -- the transimpedance amplifier, the whitening chassis, and the front-end compensation for the frequency response of those -- as yesterday, now 24-ish hours after the DCPD transimpedance amplifiers were powered on. 

Finally -- some good news!

As suspected, after the giant inductors thermalized, the low frequency response has restored to the same post-2024-vent ~0.3% magnitude drop below 25 Hz. 
Yesterday, I'd only waited 20 minutes after turning them on when I took the data from LHO:78095.
So -- clearly the thermal time constant for the inductors is longer than 20 minutes!

As I logged in this morning, the  SQZ ASC and FC ASC offload and graceful clear history scripts that I  ran and left open yesterday (whoops) reran. 15:16UTC. Before I could save sdf diffs, we went though DOWN SDF revert. There was nothing in SQZ ASC, but FC ASC got cleared. As squeezing hasn't been in a good alignment over the last 12 hours, this doesn't really matter. But if  we were in observing it would have knocked us out.

Reminder to close scripts once used. CDS is there a way we can disable this from happening?

TITLE: 05/29 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 142Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 5mph Gusts, 4mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.08 μm/s 
QUICK SUMMARY:

IFO just lost lock 14:47 UTC and now relocking

Dust monitors also have a few warnings:

*H1:PEM-CS_DUST_LVEA6      WARNING: dust counts did not change, please investigate
  *H1:PEM-CS_DUST_LVEA10     WARNING: dust counts did not change, please investigate
  *H1:PEM-CS_DUST_PSL101     WARNING: dust counts did not change, please investigate
   *H1:PEM-CS_DUST_PSL102     WARNING: dust counts did not change, please investigate

 
 

TITLE: 05/29 Eve Shift: 2300-0800 UTC (1600-0100 PST), all times posted in UTC
STATE of H1: Wind
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

A bit of a wind storm at the beginning of the shift but luckily strongest winds only lasted about an hour and allowed for locking shortly thereafter.  Had about 4-5hrs of observing during this shift (with another lockloss minutes before the end of the shift).
LOG:

• 0010 Winds drop below ~30mph!
• 0100 NLN
• 0105 nuc30
• 0113 Took SQZ Manager to FDS
  • 0115 Ran SCAN_ALIGNMENT_FDS and then SQZ Angle
  • 0140 Naoki joined me in teamspeak to look at alignment (& camilla also joined).  ZM4 was adjusted in alignment slightly again.
  • H1 range is hovering around 130-140Mpc.
  • 0411 LOCKLOSS (
• Locking notes:
  • ALSx arm took some time to lock as it had trouble staying locked (but eventually made it)
  • PRMI looked off in yaw, and I was not able to get it better by hand.  Ran a Manual Alignmnet of just the PRC.  Unfortunately, DRMI still had issues locking (even with SRM tweaks, so a full Initial Alignment was run).  After this H1 made it to NLN with no problem.
  • 0616 Back to Observing with a range around 150Mpc.
• 0752  Sadly as I typed this summary H1 had another lockloss (this was with calm winds)

J. Kissel
EDIT :: False Alarm -- see comment below!

Since I'm at the "what does it all mean?" stage of madness with the OMC DCPD Transimpedance Amplifier (TIA), I decided to make it worse -- I remeasured the original transfer function that triggered me worrying about the TIA response in after the OMC swap (see LHO:75986). I did this to try to corroborate whether there is a change in the DCPDA response above 1 kHz as mentioned in LHO:78090. 

This transfer function is the remote, DAC-driven measurement of the whole DCPD sensing chain -- the transimpedance amplifier, the whitening chassis, and the front-end compensation for the frequency response of those -- this has been described most recently in LHO:71225. 

I *don't* see a difference above 1 kHz, but I *do* see more difference in response below 25 Hz than I had in 2024-Feb-26.

See the attached transfer functions of the DCPDA chain and the DCPDB chain.

Black is pre-OMC swap, 2023-Jul-11.
Brown is post-OMC swap, 2024-Feb-26.
Red is today, also-post OMC swap, 2024-May-28.
All measurements use the S2300003 whitening chassis, and the compensation from the 2023-Mar era compensation we've been using throughout O4.

The only "oh, well it could just be" that I can think of immediately is that the DCPDs had been powered down from 10:10a to 11:30a PDT today to characterize the measurement setup in analog (see LHO:78090), and these were measured "only" 20 minutes after being powered back on at 11:50a. So -- we'll have to take the measurement again at the next opportunity -- such that the TIA electronics have what we think it the appropriate amount of time to thermalize -- a few hours.

           Just maddening.

Data lives in 
    /ligo/svncommon/CalSVN/aligocalibration/trunk/Common/Electronics/H1/SensingFunction/OMCA/Data/
        20240528_H1_TIAxWC_OMCA_S2100832_S2300003_DCPDA_RemoteTestChainEXC.xml
        20240528_H1_TIAxWC_OMCA_S2100832_S2300003_DCPDB_RemoteTestChainEXC.xml

Andrei, Sheila

We've analyzed the time-traces of the effective range (H1:CDS-SENSMON_CAL_SNSW_EFFECTIVE_RANGE_MPC) along with the alignment channels FC_WFC_A(B) and AS_A(B)_RF42 (see attached figures). We found no observable dependance between those.

On May 13th (as part of my DQ shift), I noticed a line of 4kHz glitches in the glitchgram, and they have appeared every day since then. Checking the summary pages revealed they’ve been intermittently present since Apr 8, 2024 but not previously (I checked from Dec 1, 2023 onwards). Fig. 1 shows an example glitchgram from May 13th. Figs. 2-4 show Omegascans for some of these glitches. I also created a spreadsheet to characterize these glitches, and did not find any pattern or regularity to their appearance.

I checked the aLogs for possible sources and found the SQZ angle was being tuned around the time the glitches started (aLog). I then compared the timing of the glitches to the SQZ: FC ASC channels and found a correlation between the deviation in the output and the strength of the glitches. See Figs 5-7 for examples, as well as the spreadsheet. I will be meeting with the LSC fellows on Tuesday to discuss these.