Eric, Ryan S, Camilla, Sheila

All week we have been working on getting a set of OMC scans and beam profile measurements for different psams.  We have both sets of data now, with plots and scripts coming soon next week.  

OMC scans

We started with a script that Begum gave us from HAM6 work at LLO.  We set up ASC loops to go from ASA and AS B DC signals to ZM4 and ZM5 (as described in 90742).  We struggled a while to lock the OMC on the seed beam in air, hampered by 90754.  With that noisy OMC lock, yesterday Camilla manually aligned OM3 and the OMC suspension carefully to maximize the 00 transmission.  We then added offsets to H1:OMC-ASC_QPD_{A,B}_{PIT,YAW}_OFFSET, which is not the usual location for OMC QPD offsets.  We will need to get rid of these offsets before we go back to locking. 

OMC A offset: PIT 0.088 YAW: 0.133  OMCB offset: PIT 0.27 YAW: -0.22

We found that we were able to move the psams, whih misaligns the OMC terribly, run the centering loops to the ZMs, then run the OMC QPD loops to bring the 1st order peaks back down to a couple % of the 00 peak repeatedly.  We spent some time modifying and then debugging the script that Begum shared with us.  

It takes in a list of ZM4 and ZM5 strain gauge values, moves the psams servos target to that point and waits 30 seconds with the ZM centering loops on (it doesn't check the acutal value of the strain gauge, perhaps this would be a good thing to add next time).  It then turns on the OMC QPD loops for 20 seconds.  It then takes a 100 second ramp of the OMC PZT, and saves the times and ZM strain gauge targets into a yaml file.  

There is a template you can use to watch all this at userapps/sqz/h1/Templates/ndscope/OMC_psams_scans_monitor.yml  The script that runs these sweeps is at sqzutils, or /ligo/gitcommon/squeezing/sqzutils/omc_scans_sweep_psams.py  There is also a script there that loads the data, identifies the peaks and estimates mode mismatch and misalignment there, analyze_psam_omc_sweeps.py.  A preliminary plot is attached (apologies for the color choices and linear y scale here).  

M2 profile measurements

Eric and Ryan S took a series of M2 profiler measurements of the beam on SQZT 7 today, doing the alignment procedure at each strain gauage setting (they didn't adjust ZM alignments).  Their data is in here, we will post some plots of this next week.

Note about ZM5 strain guage

While Eric and Ryan were making beam profile measurements, they ran into a situation where ZM5 would not go the strain guage setting of 2.  I was able to get it to go to 2 manually, but noticed that there were times when the strain gauge voltage dropped to zero, similar to a problem seen at LLO HAM6 recently.  We should follow up on this next week.

After getting IAS sign off from Keita, Betsy and Jason yesterday, Mitch and I went to BSC2 to start reattaching the actuators. We finished that this afternoon, according to dial indicators on the chamber we haven't moved from the locked position, but stops are still engaged. Actuators are valved in,  and I have set the alignment targets for HEPI to the current value. IPS readouts should be meaningful again for trends, just remember that they have been disconnected basically since the cartridge was pulled from the chamber, so doing alignment comparisons between before that time and now are pretty pointless. On Monday, I plan to unlock, look at lock/unlock offsets, then use the loops to servo to this locked position. If locked to unlocked shift is large, it may mean we will want to do another round of spring adjustments, but I should be able to do those from above, using the IPSs. 

TITLE: 06/26 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

Main activities today were: SQZ measurements in lvea + control room, connecting actuators for BSC2 hepi, ham3 baffling...
LOG:

• 1508-2130 Beginning Y-arm asphalt sealing for Y1.  Made it about 0.5km today. (randy.tyler)
• 1553 Re-run of SQZ sweep measurement (~40min) with SQZ injected beam (sheila.eric.ryanS)
• 1557 reboot of nuc20 for new cds overview (dave)
  • 1607-1629 reboot of nuc30 due to disk space (erik)
• 1620 Let Big D construction thru gate (MY+ camera is pretty dirty and hard to view)
• 1625-1650 troubleshoot pressure gauge HAM4 (jordan.jacob)
• 1645-1714 grounding studies @EX (robert)
• 1730-2032 HEPI actuator @bsc2 (jim.mitch)
• 1719-1728 troubleshoot (round2) pressure gauge HAM4 (jordan.jacob)
• 1759-1933 tour of the roof observation deck + lvea (robert+interns)
• 1815-1829 staging parts at HAM2 + checking pressure gauge at HAM4 (jordan)
• 1823-1935 beam profile measurements @isct7 (sheila.eric.ryanS)
• 2013-2029 quick trip to SUSR2 rack (jeff)
• 2015 troubleshoot (round3) pressure gauge HAM4 (jordan.jacob)
• 2028-2144 more beam profile measurements @sqzt7 (ryanS.eric)
• 2053-1610 removing viewports (qty2) from HAM2 (jordan.jacob.owen)
• 2111 setting up for baffling work at HAM3 (robert.disha)
  • 2122 disha joining
• 2120-2242 Finishing touches on bsc2 hepi actuators (jim.mitch)
• 2130-2257 SPI Optics lab clean-up (jeff)
• 2228-2255 Quick lvea tour (elenna+detchar group)
• 2240 VerbalAlarm changed to remove the HAM3 CPS glitch alarm we had been getting every few minutes for the last 30+hrs
• 2245-2322 HEPI pump troubleshooting (jim)

Jordan, Jake Z, Owen H

Per FRS Ticket 38164, two viewports were removed off of HAM2 and replaced with Class A 10" CF blanks.

On the East Door, port A2F2 was an uncoated ZV-800 (SN 66), and on the West door A1F1 was a ZV-800 Coated SN (R009). These two viewports will be inspected on the bench and put into spares inventory if all looks okay and passes inspection criteria.

These two blank flanges will be added to the list for leak checking during pumpdown.

After this week's HAM3 CPS work, had been hearing "HAM3 CPS Glitch" verbal alarms every few seconds, so volume reduced on Verbal.  To allow us to hear Verbal, RyanS made an edit to the tests.py file to remove the alarm for HAM3's CPS Glitches (he commented this change in the file). 

This specific alarm will need to be restored--after the CPS work is complete.

I updated the some of the medms for the blends for HAM2&HAM3 to include the SPI and CRS, added INERT_MID

Blend of four sensors: /opt/rtcds/userapps/release/isi/common/medm/hamisi/ISI_CUST_BLEND_SUPSENS_FOUR.adl

Made new block for a blend with four sensors: opt/rtcds/userapps/release/isi/common/medm/hamisi/new_FADER_4PART.adl

The blocks for 2 sensors and 3 sensors (new_FADER_PART.adl, new_FADER_3PART.adl) currently have T240 labeled instead of SPI, I didn't want to mess with those blocks, as they are used for other chambers and it's still labeled T240 in the model, but for the 4PART I did switch T240 to SPI

Made new blend fade medm screen for HAM2 & HAM3: opt/rtcds/userapps/release/isi/common/medm/hamisi/ISI_CUST_H23_BLEND.adl

Made overview screen for HAM2&HAM3:opt/rtcds/userapps/release/isi/common/medm/hamisi/ISI_CUST_H23_FADE_OVERVIEW.adl

The only thing changed was to switch which screen the ST1 BLEND FADE button takes you to the new medm.

I added and commited all these to the SVN and updated the sitemap to link the them for HAM2 and HAM3

TITLE: 06/26 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 17mph Gusts, 12mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.08 μm/s 
QUICK SUMMARY:

• Cooler, breezy & cloudy morning; there was a M6.5 EQ a few hours ago in Philippines.  DetChar meeting formally ended yesterday (so not leaving kitchen door unlocked).
• Due to RDO Fri, SQZ work may be a primary activity for the day.  There is a plan to run measurements with the purge air turned off today (which would mean NO in-chamber work). 
• Local laser hazard in East Bay continues for SQZ HAM7 work (rest of LVEA is laser SAFE except for at height).  
• CPS work continues (I know this because Verbal Alarms is overtaken by the "HAM3 CPS Glitch" every few seconds.) 
• Assume BSC2 HEPI actuator work is also ongoing into next week
• HAM3 Baffling is also still ongoing (baffles in-chamber, but still need final positioning, when allowed--BBSS prevented this Thurs).
• Other ongoing work:  CRS, SPI, EX electrical ground studies, B&K work in-chamber work, and possibly close-out  & seal-up chambers next week(?)

(Jordan, Owen, Jake, Gerardo)

The annulus sytem for HAM1 and HAM2, shared volume, was pumped down initially with a single aux cart (Hi cube), then to speed thing up a second aux cart (another Hi cube) was added via the HAM2 AIP port.  After a couple of days the ion pump controllers appears to be able to keep up with the pressure, see attached trend plot.

(Jordan, Owen, Jake, Gerardo)

The cryotrap cooldown continues, we continue to pump on the cryotrap volume with a turbo pump, the turbo is backed with a SS500 aux cart.

Small changes were the removal of the calibrated leak from the RGA tree, along with the removal of other components in preparation to install an incoming small ion pump next week.

Current pressure in the cryotrap volume is 7.38X10^-10 Torr.

Shoshana, Jim, Arnaud

The x6 HAM3 new CPS boards have been set to the following configuration (as per E2200455): 

• Chassis ungrounded from PCB (P3 jumper removed) - To avoid ground loops (see p33 of the user manual)
• All boards set to slave (P26,27,28 jumpers removed) - This is because the LHO CPS are linked to an external timing chassis and don't need a master board (as per Jim)
• Phase set to 0 (P2 jumper on) - This setting is because the targets are now independant from each other (see point #1 in page 27 of the user manual)

There was some glitching noticed on the channels that were in range prior to this work, which was fixed after this setting change (see attached). Two of the cards were set to Master before and Jim is confident this would have created problems. 

Left to do : 

1- Label the cards at the front of the boards with module SN and corner #
2- Disconnect the grounding to the chamber of the crate on the +Y side 
3- Label the in-air lemo cables with H1, V1, H2 ...
4- Update ICS with the new boards SN
5- Gather the cards that were removed from WHAM3 to send back to microsense for recalibration with a new set of sensors (RMA)

The tracking spreadsheet for this ECR was updated here: E2500184 

(Jordan, Gerardo)

We inspected the 5 viewports on the west door of HAM2.

We found on viewport A1F4 the typical smudge or print left by first contact the print appears to be on the inside, but not the vacuum side (this VP has two windwos).  We also noted a scratch on the outside window (not under vacuum), around 1 O'clock and about 3/4" away from the edge, we contacted Keita who was walking by the area and we asked him if the location of the smude/scratch were on the path of beam, no they are not.  BTW, VP4 is a high quality wedged viewport, a double window, type D1101714.

Then on A1F2 ZV-800 viewport we noted some scratches, something was dancing on the window, since it appears as a single scratch with multiple turns.  This viewport was removed and replaced with a spare ZV-800 type.  SN of new unit is 0098, old scratched and full of particulate viewport serial number 63.

All other viewports nothing to report, A1F1, A1F3, A1F5.

Arnaud, Marie, Jeff, Oli

Compared to the BSFM, the cross coupling in the BBSS from P to Y is mught higher (This plot shows ~ 2 orders of magnitude, but I don't want to confirm that yet since the data fudge for the BSFM might be incorrect).

I made a comparison of the last few BBSS P to Y measurements and compared them to an old BSFM P to Y measurement.

We found that the P to Y cross coupling looks a lot like just Y to Y (bright blue), so there is much more Y than there should be.

There is still some more work to be done to absolutely confirm this, but current in progress results can be found in /ligo/svncommon/SusSVN/sus/trunk/BBSS/Common/Results/comparetripleparams/2026-06-25_BBSSvsBSFM, r13050.

Following on from alog 90738, we last had the corner alignment with the BBSS at PIT +115 and YAW -1557.  We decided to offload this YAW to the HEPI so the team embarked on that yesterday, likely another alog from IAS/SEI on that move later.  Today we went and looked at the corner beam pointing with Keita refining the BBSS alignment to PIT +107, YAW +441 (see his alog coming). 

So now, Jim and Mitchell are embarking on Actuator attachment at the piers.  We will relook at the BBSS cage position with the FARO shortly after they are complete, and then re-peek at the corner alignment likely early next week.

Meanwhile, the BBSS PIT to YAW cross coupling investigaton continues...

Jeff, Arnaud, Betsy, Oli

Yesterday we checked the coil response for the BBSS QOSEMs. We did this at the BBSS M1 QOSEM satamp. Everything is looking good and as we expected.

We did this by putting the BBSS in SAFE, then unplugging the db15's that go to the coil drivers. In their place Jeff plugged in a fancy breakout board that separated out each of the 4 channel pins. The resistance of each of the reading device channels is listed below:

 With this channel breakout board we then went channel by channel to measure voltage. We turned the master switch ON so counts can head out from the COILOUTF filter bank. For each channel, we noted the COILOUTF filter bank gain sign, and if there was any voltage read out when no offsets were put in. Then we put an OFFSET in the COILOUTF filter bank and noted the voltage that we were reading. We did this for multiple OFFSETs for each channel. After testing each channel, with an offset still on, we would check the other channels to see if anyone else was seeing anything more than their default reading with no offsets, which they never saw anything different from that. Here is that data:

You can see that the voltage signs are all consistant with the sign of the OFFSET * COILOUTF gain, and the values are all pretty consistant as well.

After we were done reading out the voltages for SUS_BS_85, we put offsets of -20,000 in F1, F2, and F3 and checked the voltages on all three channels. All three channels read the same voltage as they had when we had tested them individually at -20,000 counts. That table is below.

Jeff, Betsy, Arnaud, Oli

Yesterday afternoon we went to the BBSS QOSEM satamp and checked the coil resistance. We did this by putting the BBSS in SAFE and then unplugging the Satamp to Duopus cables one by one. Each of these three cables have the pins for two QOSEMs, split as CH1 + CH2, CH3 + CH4, and CH5 + CH6. Each cable was unplugged and then the pins for each coil probed. Below are the results. These values are all pretty similar.

Today Gerardo and I removed the unused HAM ISI Oplev viewports from the VP7 ports of both the -X input manifold and the +Y output manifold.  The ports were blanked off with 10" CF blanks.  I noted a series of 3 scratches on the angled flat of the flange, but the knife edge itself wasn't noticeably deformed.  See pics.  

Note to VAC: These will need to be leak checked during pumpdown.

Below is the analysis for data taken on the FC path: between ZM1 and ZM2 and between ZM2 and ZM3, with Nanoscan, see Camilla's log 90573. As a reminder, ZM1 are flat optics, ZM2 is a PSAM with variable curvature, FC1 HR side is flat, AR side is curved with RoC ~1m. 

The data suggest that the OPO mode is slightly different from O4 OPO, and also strongly suggest a new optimal ZM2 PSAM voltage can be found within the range. 

We measured the beam profile at 5 different points after ZM1 with A:L2 lens at its nominal 0 position (sled that the lens lives on is flush to its translation stage on both front and back edges). At the last point with A:L2 at 0, we realized it would be pertinent to measure beam profiles for the two extremities of the A:L2 translation stage: -13 mm, which is closer to ZM1 by 13 mm and +17 mm, which is 17 mm further from ZM1. We then proceeded to take 5 measurements (again downstream from ZM1) for each of these lens positions. The nanoscan screenshots for each measurement are attached in the .zip folder. 

The attached gif shows the beam waist position estimation extracted from the beam profile scans downstream ZM1, for all three A:L2 positions. The "target" and "O4 x/y" come from Keita's log 59515. The overlap plot attached shows the field overlap in percentage for all three A:L2 positions, with target and O4 beam parameters. With A:L2@0, the overlaps are above 99%, which bodes well for the FC mode matching prospects. There could potentially be a better mode matching solution to the "target" or "O4" for A:L2 between 0 pos and -13mm pos. However, the following measurements betwen ZM2 and ZM3 suggest fine-tuning of A:L2 position will not be necessary. 

We also measured beam profile between ZM2 and ZM3 for three different points, setting ZM2 PSAM voltage to 4 different values at each point. The "nominal" O4 strain gauge (S.G.) for ZM2 has been 3.15 V, which corresponds to ~ 60 or 90 V pzt supply voltage depending on which direction one scans from. The edges of the psam range are 0 V and 196 V, which corresponds to ~1.2-1.3 V and ~6.04 V S.G. respectively. In the interest of more uniform sampling of the available psam curvatures, we also chose to sample 4.5 V S.G. (~120 V or 150 V). 

This table shows experimental data mapped to radii of curvature of the ZM2 mirror, using Camille's E2100298. The exact PZT strain gauge/ PZT supply voltage that gives a certain RoC is affected by the hysteresis curve i.e. sweep direction.

Attached gif for propagation between FC1 and ZM2 show esimated beam parameters for all four SG cases: 1.3, 3.1x, 4.4x and 6.0x V. The exact values for the strain gauge varied from one beam profile position to the next, however it should be good enough to tell if we have enough range on ZM2 or not.

The gif switches between different SG values once every 2 second, the lefthand plot is useful in looking at the beam divergence near FC1 while the righthand plot is a zoom-in around the beam waist. Looking at the estimated beam waist position for 1.3 V and 3.1x V cases switching across the "FC x/y waist", "VOPO target waist", ''O4 x/y waist", we can guess there could be a better mode matching solution between these two SG values. "FC x/y waist" comes from the Finesse eigenmode solution for the FC path (thanks Kevin Kuns!), target and O4 values are the same from the above-mentioned Keita log, assuming ZM2 curvature to be 0.85025 m (3.15V SG), and the following distances between the optics: A:M3 --> ZM1: 158.2 mm, ZM1--> ZM2: 1498.625 mm, ZM2 --> ZM3: 1821.497 mm, ZM3--> FC1: 1000.261 mm. Camilla extracted these distance values from D1900365-v1.

Knowing the applied PZT voltage and the corresponding RoC, we can use the measurements at 3.1x V and 1.3 V to estimate the mode matching we would obtain if we swept the RoC between that of these strain gauge values. The attached FC mode matching projection plot is computed by taking beam parameter estimated from the beam size measurements for 3.1x V, propagates the beam back to ZM2, unapplies the estimated RoC (decreasing RoC value was used informed by data, indicated in bold in the above table), then reapplies the RoC between these two values, after the overlap with the FC eigenmode is calculated. This projection suggests that mode-matching points with >99% overlap for both x and y axes are accessible. Clearly, there is varying astigmatism with strain gauge setting, see beam profile plots where 3.1x and 6.0x V shows beams with smaller astig. than the other two points. Since the PSAM characterization data gives only a single RoC number rather than separate x/y effective curvatures, the projection should be interpreted as approximate. In practice, the final optimization should be done empirically.

The effect of the astigmatism is also apparent in this defocus vs beam size at FC1 plot that shows mode matching contours. The calculation is made at the FC1.p2.o plane in Finesse.

J. Kissel

Quick summary of status and things done before the weekend:
    2026-05-14 
       - Secured new D2400143-v6 breadboard to 1"Dx6"L posts
       - w/ J. Freed Helicoiled most holes
  
    2026-05-15
       - Finished helicoiling and confirmed all holes have helicoils.
       - Brought out IXM100 mounts that are to replace CVM100 mounts, confirmed left vs. right-handed assignment
       - Fit-checked (success!), then installed new version of 45 deg periscope adapters to M_M4 and M_M5 mounts. 
       - Aligned periscope adapters as best possible by eye
       - Migrated over and re-cabled up all photodiodes per wiring diagram and cable routing defined in LHO:90228.
       - Migrated R_F1 and M_F1 fiber collimators, confirming and adjusting alignment of slow-axis w/ vertical flat.
       - Re-connected optical fiber input to each collimator.
       - Re-introduced beam on to breadboard confirming that NPRO and Laser Prep Chassis still work as good as we left it. 
       - Measured raw power from R_F1 and M_F1 fiber collimator output using S121C power meter.
       - Aligned R_F1 and M_F1 fiber collimator output using 
           - D2500080 alignment iris target assemblies
           - D2400143-v6 holes 89 + 101 for R_F1 and 101 + 80 for M_F1 and 
           - S121C behind the "far" iris, maximizing power throughput.
       - Migrated R_P1 and M_P1 thin-film polarizers.
       - Measured P-pol (TRANS) and S-pol (REFL). 
       - Migrated D_R_P1 and D_M_P1 beam dumps.

Optical power going into the mock PSL input fiber is ~195 [mW] as we left it, and internal laser prep chassis reads 7.8 [V] implying that input power to the chassis is the same 173 [mW] we set it to, to match the real PSL input (see LHO:89693).

RF power on power monitors from prep chassis are as expected, in the 750 +/- 10 [mV] range.

Measuring power with our trusty S121C with ThorLabs PM100-D readout (confirmed to be measuring at 1064 [nm] wavelength):