TITLE: 04/11 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 158Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY: A power glitch this morning cause the EY HEPI pump to trip off, but after it was recovered, we finished initial alignment (and fixed SRY), then all the way up. We've been locked for 5.5 hours.
LOG:

• 1741 Observing

TITLE: 04/11 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 157Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 12mph Gusts, 7mph 5min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.17 μm/s
QUICK SUMMARY: H1 has been locked and observing for over 5 hours.

• Wind is low and microseism is trending down
• All systems look good

In last night's lock, the range steadily increased overnight, this looks like it is a result of the cleaning being better tuned for a thermalized IFO than for early in the lock.

We have for a long time had a reference of 165 Mpc on the front wall, which is from a time of OM2 warm.  This was the range reported by H1:CDS-SENSMON_CAL_SNSW_EFFECTIVE_RANGE_MPC, which did not have time dependent calibration corrections applied.  The range with calibration corrections applied at that time was H1:CDS-SENSMON_CLEAN_SNSC_EFFECTIVE_RANGE_MPC, closer to 160 Mpc. 

The attachment shows the spectrum and range comparison of last night to our previous reference time. 

In order to reduce the duct static pressure of the hot and cold decks, we reduced the airflow rate from 15,000 CFM to 13,000 CFM. This lowered the static pressure in both ducts by roughly .05" which helped reduce the airflow noise in the control room. Currently one of the dual duct VAVs in the control room also has a degraded control board which will be replaced once available and should help further reduce the airflow noise. 

J. Kissel, F. Clara

Continuing along the design process for SPI, I asked Fil what we typically do for optical fiber "patch panels," where we want to modularize long optical fiber runs. He showed me this example of a fiber patch panel that uses off-the-shelf optical feedthrough parts. Note, as is specifically visible in IMG_4258.jpg, there is no optical element within the feedthrough. Hence, the feedthrough just serves the purpose of aligning the to connecting fibers for a (potentially lossy) brief fiber-to-air-and-back transition.

This isn't the only way we do it; for comms fibers like what goes from the timing master in the MSR to the timing fanout in the CER, we do somethin like what's shown in IMG_4254.jpg.

Alternatively, when optical fibers enter / exit a laser table (e.g. SQZT0 or the ALS ISCTEX or ISCTEY tables) we build our own labeled panel, that holds an off-the-shelf thorlabs feedthrough -- for example, the LO beam for the SQZ'er's panel is D1700147 which uses the Thor Labs part #ADAFC4.

FAMIS25985

ITMX ST1 was looking a bit higher, but perhaps not an issue yet. Everything else looks good.

Sheila, Jennie W

We have some a series of peaks inthe DARM spectrum from 25-34 Hz, some of which have broad shoulders, which have been with us for a long time but are now more prominent due to improvements in low frequency sensitivity. 

I took a 2mHz resolution spectrum from a time with good range last night (165 Mpc).  I tried searching all of these frequencies on the alog but found none of them.

In the resonances wiki there is a ERM mode listed at 25.6281 (calculated not measured).  There is a BS roll mode (R3) calculated as 25.9175 Hz with a link to 49643, which suggests it is 26.06 Hz

Jennie searched Gabriele's Bruco from last night, and found that there are PRCL coherences for some of these peaks.  I retook the 2mHz spectra for a comparison of the times before and after the PRCL offset was first tuned, you can toggle between this and this screenshot to see the difference.  Since this PRCL offset was first put in, we have changed the BS camera spot position which brought back the board PRCL coherence this offset was getting rid of (76814).  The PRCL offset did seem to reduce the broad noise in DARM around these peaks, as you can see in the third attachment with with more binning. 

Following up from my alog77064 saying that this needed to change, today I moved SRY triggering from POP_A_DC to AS_C_NSUM with new trigger threshold of upper=0.005 and lower=0.004. This worked well and gave us a quick, well aligned DRMI during main locking. The Acquire_SRY state used to lower the trigger thresholds after a few minutes for times that we had less power on POP_A, I've removed the lowering but added a notification to check the alignment or triggering.

I've updated ALIGN_IFO to reflect this and committed to the SVN. I anticipate we might need to fine tune these thresholds over the coming weeks.

The ETMY HEPI pump tripped this morning around 14:35 UTC (7:35am PST) potentially from the CS power glitch? I ended up going out to the Yend mech room and reset the VFH panel to reset the HEPI pump controller. The light was still on when I first checked the panel, I pressed the green ON button first which did not fix the issue, I then cycled it off and back on, pressing the red then green button, confirming that the light went off and on which Jim confirmed to have fixed it. Jim then brought back the pressure to 70PSI from  the Beckoff_Pump_Controller medm.

Thu Apr 11 10:12:01 2024 INFO: Fill completed in 11min 57secs

Jordan confirmed a good fill curbside

BruCo scan from a good range time from last night: https://ldas-jobs.ligo-wa.caltech.edu/~gabriele.vajente/bruco_1396823046_GDS_CALIB_CLEAN/

Some highlights:

• there is coherence with PRCL between 15 and 40 Hz, and also with REFL_LF (RIN). This is similar to what we oberved before, and we managed to fix this by tuning the PRCL offset
• there is some coherence with CHARD_Y and INP1_Y at low frequency. This could be improved by trying the new HAM1 FF, since for both CHARD_Y and INP1_Y we expect some improvement using the new FF filters (note that we are not doing any HAM1 FF to Y now).
• there is little coherence with DHARD_Y at low frequency, so maybe the AS WFS offset is still ok

The last two plots show what improvement in sensitivity we should be able to get by reducing the above noise couplings, and which of the above noises contribute most at each frequency. Those plots are produced by offline subtraction with NonSENS

The MSR UPS went onto battery backup for 2 seconds at 07:35:02 due to an AC power glitch.

TITLE: 04/11 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Aligning
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 3mph Gusts, 2mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.15 μm/s
QUICK SUMMARY: 17 hour lock ended about an hour ago. H1 is currently running an alignment, but stuck at green locking with no light on Y arm. HEPI and both ISI statges at EY have tripped during locking, not sure of the cause yet.

Starting around 00:20 UTC (5:20pm PDT) this evening, the air has been much louder in the control room. Called Bubba to ask about it, and he says it's related to Eric's work today on the AHU-3 VAV (alog77092) and that the temporary ducting may have come undone. Other than it being louder in the control room, the duct should be fine and will be addressed in the morning.

I have not noticed a noticeable change in the IFO range since this noise increase, but I'll tag PEM and DetChar just in case.

HAM1 ASC FF was off from 1396381762 to 1396382969 (20 minutes starting 90 minutes into lock). Using this data I could retune the feed forward filters that subtract HAM1 motion from the ASC signals.

I based the attached jupyter code on an older version, and automated the subtraction training for all pitch and yaw ASC signals (CHARD, INP1, PRC2, DC1 and DC2).

Looking at the filters that are loaded now, we used to do the FF only for the pitch degrees of freedom. The subtraction seems to be doing something good in yaw too, so I suggest we upload and try the yaw feedforward filter.

The first plot shows the expected subtraction predicted by NonSENS. The second plot shows the absolute value of the transfer functions.

Finally, the attached text file contains the foton filter definitions for all the feedforward filter banks. I haven't upload those flter to foton, and not tried them yet. Before each filter there is the name of the filter bank where it should be loaded, for example H1:HPI-HAM1_TTL4C_FF_CART2ASCP_1_1

WP 11805
ECR E2400083

Lengths for possible SPI Pick-off fiber. Part of ECR E2400083.

PSL Enclosure to PSL-R2 - 50ft
PSL-R2 to SUS-R2 - 100ft
SUS-R2 to Top of HAM3 (flange D7/D8) - 25ft
SUS-R2 to HAM3 (flange D5) - 20ft