Jeff K, Betsy, Rahul

Making a late entry for SRM rubbing investigation which happened last Thursday (see alog 79425). We went to HAM5 chamber and closely inspected SRM and all the EQ stops for any signs of rubbing. I couldn't see any of them touching/rubbing the chain, also at some places it was hard to see since the suspension is covered in shroud. However, at two places I felt the EQ stops were too close for my comfort, hence I very slightly adjusted them (to create a visible air gap) - first at optic barrel EQ stop and second at the metal upper mass stage. 

Using a dental mirror I also checked the LF and RT bosem flags and found that that LF BOSEM flag is very close to the top LED/PD, with both offsets ON and OFF (was hard too spot any difference) - I am attaching a picture which I took on Jeff's phone. I did not adjust the LF bosem - since we didn't wanted to change the alignment.

Closes FAMIS#21186, last checked 76673

Cooling (attachment1)
Everything looking good!

Environment (attachment2)
Everything looking good!

Laser (attachment3)
Everything looking good

Stabilization (attachment4)
FSS_TPD_DC has drifted down to ~0.65, which is lower than it''s been in a while, and PMC REFL has continued to rise and is now sometimes surpassing 20.2

Mon Aug 05 08:05:25 2024 INFO: Fill completed in 5min 22secs

TITLE: 08/05 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 5mph Gusts, 3mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.06 μm/s
QUICK SUMMARY:

IFO is in MAINTENANCE for VENTING

This week we plan on closing remaining doors (HAM5) and prepping to pump down.

There was an emergency air instrumet issue Sunday Evening: alog 79443

Gerardo M., Janos Cs.

After the aLog of Dave (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=79442), we came onsite and found that the instrument air supply is not operational. In the reservoir tank the pressure was still ~80 psi, but the device 'as it is' was not operational; so the solenoid valve wasn't open to the system, and in general the whole system was off - which explains Dave's aLog 79442. When we arrived on site, GV6, GV7, and GV8 were already soft-closed.
The following actions have been taken:
- The instrument air supply was isolated from the instrument air system
- A compressed air cylinder was hooked up to the system in the mechanical room (see picture), and we were slowly ramping up the air pressure, and so all the GVs opened up
- GV7 was intentionally soft-closed after this, to prevent any undesirable X-manifold pressure raise, if GV7 decides to close
- The X-manifold turbo was switched on, and after its pressure went below the pressure in the manifold, it was valved in. Now it is holding the X-manifoild's pressure at 3-4E-8 Torr. It will remain like this until the pumpdown (upside of the whole story that we will have the X-manifold turbo as an additional firepower during pumpdown)

Other considerations:
- As the instrument air system consumes the air very fast (from 1500 psi to 1000 in half an hour - note here that it opened all the GVs, so it won't be this bad all along), GV6 and GV8 can close before morning
- To mitigate this potential issue, Nitrogen or compressed air cylinders will be hooked up to GV6 and GV8 directly, to minimize the losses (especially, if the air supply cannot be fixed quickly)
- After the GVs soft closed in the beginning of this whole story, the pressures in the beamtube and in the CPs didn't change drastically, they followed the typical daily pressure cycles

Alarms have just been sent for low compressed air pressure in signal H0:VAC-MR_INSTAIR_PT199_PRESS_PSIG

24hour trend attached.

Sun Aug 04 08:03:48 2024 INFO: Fill completed in 3min 45secs

Short fill, but pressure spike looks good. Gerardo signed it off as a good fill.

Sat Aug 03 08:05:13 2024 INFO: Fill completed in 5min 10secs

TITLE: 08/02 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Nobody
SHIFT SUMMARY:

IFO is in MAINTENANCE for VENTING

HAM6 doors on as of 17:50 UTC.

Ryan C checked and turned on dust monitors - all except for known PSL102 are on. alog 79427.

LOG:

Closes FAMIS 26277

Laser Status:
    NPRO output power is 1.821W (nominal ~2W)
    AMP1 output power is 65.08W (nominal ~70W)
    AMP2 output power is 137.6W (nominal 135-140W)
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN
    PDWD watchdog is GREEN

PMC:
    It has been locked 24 days, 1 hr 50 minutes
    Reflected power = 19.12W
    Transmitted power = 107.6W
    PowerSum = 126.8W

FSS:
    It has been locked for 15 days 22 hr and 23 min
    TPD[V] = 0.6675V

ISS:
    The diffracted power is around 2.3%
    Last saturation event was 16 days 23 hours and 36 minutes ago

Possible Issues:
    PMC reflected power is high
    FSS TPD is low
 

SEI seismometer mass check - Monthly - Closes FAMIS 26492

I've also attached the WD_ALL Mini Screen of what states the SEI platforms were in (FAMIS calls for DAMPED or ISOLATED but since we're venting, some of these are in different variants of damped or isolated.

T240

Averaging Mass Centering channels for 10 [sec] ...
2024-08-02 13:21:31.272178
There are 27 T240 proof masses out of range ( > 0.3 [V] )!
ETMX T240 2 DOF X/U = -0.632 [V]
ETMX T240 2 DOF Y/V = -0.461 [V]
ETMX T240 2 DOF Z/W = -0.522 [V]
ITMX T240 1 DOF X/U = -1.764 [V]
ITMX T240 1 DOF Y/V = -0.302 [V]
ITMX T240 2 DOF X/U = -0.476 [V]
ITMX T240 2 DOF Y/V = -0.35 [V]
ITMX T240 2 DOF Z/W = -0.469 [V]
ITMX T240 3 DOF X/U = -1.844 [V]
ITMX T240 3 DOF Y/V = -0.387 [V]
ITMY T240 1 DOF Y/V = -0.472 [V]
ITMY T240 1 DOF Z/W = -0.611 [V]
ITMY T240 2 DOF Z/W = -0.629 [V]
ITMY T240 3 DOF X/U = -1.345 [V]
ITMY T240 3 DOF Y/V = -0.349 [V]
ITMY T240 3 DOF Z/W = -1.75 [V]
BS T240 1 DOF X/U = -0.594 [V]
BS T240 1 DOF Y/V = -0.928 [V]
BS T240 1 DOF Z/W = -0.457 [V]
BS T240 2 DOF X/U = -0.542 [V]
BS T240 2 DOF Y/V = -0.424 [V]
BS T240 2 DOF Z/W = -0.626 [V]
BS T240 3 DOF X/U = -0.712 [V]
BS T240 3 DOF Y/V = -0.676 [V]
BS T240 3 DOF Z/W = -1.191 [V]
HAM8 1 DOF Y/V = -0.505 [V]
HAM8 1 DOF Z/W = -0.812 [V]

All other proof masses are within range ( < 0.3 [V] ):
ETMX T240 1 DOF X/U = -0.133 [V]
ETMX T240 1 DOF Y/V = -0.112 [V]
ETMX T240 1 DOF Z/W = -0.159 [V]
ETMX T240 3 DOF X/U = -0.1 [V]
ETMX T240 3 DOF Y/V = -0.226 [V]
ETMX T240 3 DOF Z/W = -0.103 [V]
ETMY T240 1 DOF X/U = 0.022 [V]
ETMY T240 1 DOF Y/V = 0.09 [V]
ETMY T240 1 DOF Z/W = 0.148 [V]
ETMY T240 2 DOF X/U = -0.098 [V]
ETMY T240 2 DOF Y/V = 0.152 [V]
ETMY T240 2 DOF Z/W = 0.049 [V]
ETMY T240 3 DOF X/U = 0.155 [V]
ETMY T240 3 DOF Y/V = 0.041 [V]
ETMY T240 3 DOF Z/W = 0.089 [V]
ITMX T240 1 DOF Z/W = -0.092 [V]
ITMX T240 3 DOF Z/W = -0.289 [V]
ITMY T240 1 DOF X/U = -0.25 [V]
ITMY T240 2 DOF X/U = -0.08 [V]
ITMY T240 2 DOF Y/V = -0.185 [V]
HAM8 1 DOF X/U = -0.287 [V]
Assessment complete.

STS

Averaging Mass Centering channels for 10 [sec] ...
2024-08-02 13:24:48.269297
There are 2 STS proof masses out of range ( > 2.0 [V] )!
STS EY DOF X/U = -3.98 [V]
STS EY DOF Z/W = 2.725 [V]

All other proof masses are within range ( < 2.0 [V] ):
STS A DOF X/U = -0.679 [V]
STS A DOF Y/V = -0.648 [V]
STS A DOF Z/W = -0.561 [V]
STS B DOF X/U = 0.287 [V]
STS B DOF Y/V = 0.996 [V]
STS B DOF Z/W = -0.446 [V]
STS C DOF X/U = -0.848 [V]
STS C DOF Y/V = 0.865 [V]
STS C DOF Z/W = 0.506 [V]
STS EX DOF X/U = -0.136 [V]
STS EX DOF Y/V = -0.016 [V]
STS EX DOF Z/W = 0.076 [V]
STS EY DOF Y/V = 0.037 [V]
STS FC DOF X/U = 0.24 [V]
STS FC DOF Y/V = -1.064 [V]
STS FC DOF Z/W = 0.627 [V]
Assessment complete.

Closes FAMIS#26320, last checked in 79324

Corner Station Fans (attachment1)
- Both MR_FAN2 accelerometers show the fan becoming noisier very erratically starting yesterday (08/01) at ~07:16UTC, so just after midnight Pacific time (attachment2). It looks like accelerometer 2 isn't getting as loud in the last 12 hours as it had been getting before that, but is still jumping around a lot. Accelerometer 1 however, looks like every time it jumps up, it's a bit louder than the previous time. Definitely should be checked out!
- MR_FAN6 1 starter getting a bit noisier 07/31 14:51UTC(attachment3), but it's a consistant noisy, and looking back at last week(attachment4), the noise levels had been similar last week before they were (I assume?) corrected.
- MR_FAN5 2, which had been pretty noisy last week, finally went down in amplitude five days ago
- All other fans are looking normal and within range.

Outbuilding Fans (attachment5)
- All fans are looking normal and within range.

(Chris S., Eric O., Travis S., Tyler G., Gerardo M.)
Both doors, ∓X, were installed on HAM6.  No issues were encountered during the installation process.

TITLE: 08/02 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 10mph Gusts, 6mph 5min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.05 μm/s
QUICK SUMMARY:

IFO is in MAINTENANCE for VENT

Pardon the accidentally late alog (that never made it out of draft).

HAM6 Doors are back on as of 17:50 UTC.

As Ryan C reported yesterday, LVEA dust 5 is reporting a low battery and dust 6 stopped running 16:28 Wed 31jul2024 PDT. Attachment shows MEDMs and 7 day trends of 300nm particulate counts.

I was running the TFs for SRM to confirm that the suspension is good before we close HAM5, but the transfer function for L was a noticable amount lower in magnitude as compared to the measurements taken on July 17th right before we vented HAM5(pdf). We reran L but this time with the OPTICALIGN offsets turned ON, and the results matched our pre-vent measurements, which seemed strange and prompted looking into whether the RT OSEM has a problem. I've looked back at the state of SRM when the July 17th transfer functions were run, and T, V, R, P, and Y were run in DAMPED and OPTICALIGN offsets were OFF(T&R, V&Y, P). HOWEVER, when the L transfer function was run, SRM was ALIGNED and OPTICALIGN offsets were ON (P: 4254, Y: -9231)(L pre-vent). So that's why today's regular (offset OFF) L didn't match the pre-vent L, and why my second measurement of L with the offset on did match.

Yaw is the only other dof that was affected by the offsets being ON vs OFF, but the pre-vent Y measurements were taken with the offsets OFF, and these match with today's offset OFF measurements so we're all good there.

I'm not sure if there are still concerns about the RT OSEM on SRM M1, now that we know why L matches the pre-vent L, so I'm not sure if these results clear us for closing HAM5 or not.

Main set of measurement results (2024-08-01_2000) - SRM DAMPED, OPTICALIGN offset OFF:

$(sussvn)/HSTS/H1/SRM/SAGM1/Results/2024-08-01_2000_H1SUSSRM_M1_ALL_TFs.pdf

Second set of measurement results (2024-08-01_2200) - SRM DAMPED, OPTICALIGN offset ON:

$(sussvn)/HSTS/H1/SRM/SAGM1/Results/2024-08-01_2200_H1SUSSRM_M1_ALL_TFs.pdf

Full comparison of Pre-Vent, Post-Vent offset OFF (main) set, and Post-Vent offset ON set

$(sussvn)/HSTS/Common/Data/allhstss_2024_July17vAug01_H1SUSSRM_M1_PreVsPostOFIVent_ALL_TFs.pdf

SUS HAM 5-6 System Wiring Diagrams D1002740
Grounding and Shielding at LIGO T1200131

Things to note:

1. HAM6 ISC cabling was not checked for ground loops
2. Short found on the OFI (cable SUS_SQ_30). Pin 13 shorting to ground. In-chamber ground NOT resolved.
3. All cables listed below passed testing:

SUS_HAM5_001 (SR3 Top)
SUS_HAM5_002 (SRM/SR3 Shared)
SUS_HAM5_019 (SR3 Middle)
SUS_HAM5_020 (SR3 Bottom)
SUS_HAM5_003 (SRM Top)
SUS_HAM5_025 (SRM Middle)
SUS_HAM5_026 (SRM Bottom)
SUS_ZM6_21 (ZM6)
SUS_HAM6_10 (OMC Top/Left)
SUS_HAM6_11 (OMC Right/Side)
ISC_236 (OM1)
ISC_237 (OM2)
ISC_238 (OM3)

J. Kissel, B. Weaver

Picking up from the recommendations from LHO aLOG 60494 and LHO aLOG 60498 regarding what to do with the HXTSs H1 SUS SRM and H1 SUS SR3 OSEMs "issues" respectively, Betsy and I followed the recommendations for both SUS today, and centered all OSEM values such that they're at mid-range when the SUS are at the position they are when in-vacuum, during nominal low noise.

For SR3, this was *very easy*, and just involved re-centering the M1 SD OSEM. Since SD is not involved in any alignment control, we merely need the flag position to sit in the middle of the calibrated range. So, Besty backed out the OSEM from its previous position at -76 [um], to ~0 [um].

For SRM, this was more of a process, but the process outlined in LHO:60494 actually worked really well.

To the end user, though it may *appear* as though alignment of H1 SUS SRM has changed, if one solely looks at the DC position of OSEM sensors to reflect mechanical alignment, but this is not the case. Today's exercise proves (albeit crudely and imprecisely) that the actuation strength of the coil-magnet systems of the BOSEMs is roughly constant across/within the range the of the LED / PD shadow sensor system, and assuming such we successfully centered the OSEM sensors around the position of the flags when the coil magnet systems are steering the SUS into the place that the IFO is happy during nominal low-noise.

I attach detailed notes of all the steps along the way, and I'll add a comment to this log that has the "in vacuum, during nominal low noise" trends that I used to inform where we want the SUS to be. The trends were taken from a ~24 hour stretch in May 2021, *after* we swapped ITMY and the IFO was aligned around a "point absorber free" ITMY.
Note, because there is signficant low frequency DAC request from the global length and alignment loops when in nominal low noise, I recreated that additional requested DC position adjustment (beyond just the slider values) from global control by adding OFFSETs in 

Also of interest during this process was gathering the second ever open light current values for the M1 BOSEMs. As mentioned in LHO:60494, I dug up the first and only measurements from 2014 in LHO:60477, and we now have a definite measure of the decay of these 6 BOSEMS over 7.5 years. In short, there is ~20% decay in open light current. But, that doesn't mean I want to replace them -- my gut tells me "we still have time."
Full data listed in the table below, with the new open light current (OLC) value in bold.
              OLC 2014    OLC 2014      OLC 2021   OLC 2021     2014-2021    2014-2021    (2014-2021)/2014     
              [ADC ct]    [PD uA]       [ADC ct]   [PD uA]      [ADC ct]     [uA]         [%]
SRM M1 T1     26908       68.431        20585       52.35         6323       16.08        23.499
SRM M1 T2     25472       64.779        18996       48.309        6476       16.469       25.424
SRM M1 T3     28670       72.912        22119       56.252        6551       16.66        22.85
SRM M1 LF     27764       70.608        20831       52.976        6933       17.632       24.971
SRM M1 RT     26272       66.813        21110       53.686        5162       13.128       19.648
SRM M1 SD     25516       64.891        18715       47.595        6801       17.296       26.654

Note: even though we *measured* new open light current values, we did *not* update the compensating offset or gain.
I'll need to think a bit more about that that means in terms of systematic error in the OSEM displacement calibration.