TITLE: 02/04 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 6mph Gusts, 5mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.43 μm/s 
QUICK SUMMARY:

Work continues in chamber

Reminder that the LVEA is LASER SAFE EXCEPT around HAM1/2 and at height.

Functionality test for the corner station turbo pumps, see notes below:

Output mode cleaner tube turbo station;
Scroll pump hours: 7287.3
Turbo pump hours: 7309
Crash bearing life is at 100%

X beam manifold turbo station;
Scroll pump hours: 3389.9
Turbo pump hours: 3394
Crash bearing life is at 100%

Y beam manifold turbo station;
Scroll pump hours: 4160.3
Turbo pump hours: 2829
Crash bearing life is at 100%

FAMIS tasks 31332, 31340 and 31348.

Jennie W, Masayuki N, Keita K, Betsy W

Today we worked on improving the mode matching of the HAM1 output beam to the IMC. We also noticed the beam was going through the EOM and clipping somewhere inside so had to move the EOM up and sideways by a small ampunt to fix this. We will need to redo the RF electrical testing and the modulation depth testing for the EOM.

We improved the mode-matching of the HAM 1 output beam to the IMC by moving the lens L2 further away from JM2. We did 3 moves of 1 inch each and regained the alignment into IMC each time by using JM3 and JM2 to regain the pointing. At the end of this process we had a mode-mis-match of 1.1 % into the IMC.

After this a clipping of the beam was spotted by Keita somewhere between JM2 and JM3. We traced this down to the beam clipping somewhere inside the EOM crystal. This was fixed by shimming up the EOM at three points, after this we checked the mode-mis-match and it was 0.7%.

Then we realised there was still some clipping in pitch and so moved the EOM towards the -Y side of the table slightly. After these moves the mode mismatch was still 0.63 %.

Then after some alignent checks Keita and Masayuki have realised we need to rotate the EOM relative to the beam. This will require a sawn-off allen key as one of the 3 bolts required to yaw the EOM on its base is too near the sma connector elbows.

Camilla informed me that the non-magnetic tools might have one clean sawn-off 1/4 " allen key so left these in a tote bagged up on the + Y side outside the clean room.

Randy, Sheila, Betsy, Kar Meng, Camilla

After Sheila and Kar Meng found an issue with FC QPD A segment 3 88991, and after discussion with Ali James, Sheila went into chamber to test it.

Started with flashlight to confirm A vs B. Then after unplugging QPDs at SQZ rack, Sheila removed the diode detector holder D2000384 from the enclosure D2000246 (marked part #4). Once the cables were plugged back in at the rack, the signals on segments 1, 2, and 4 fell to zero but the segment 3 signal stayed railed at +30. This shows the issue is most likely inside the sealed enclosure, which is not a trivial fix. We attempted to swap the in-vac cables on the diodes to be sure the issue isn't in the in-vac cables or feed-through the cable was hard to removed so we stopped. Finished with a flashlight test again.

After consulting Safety on the technique, we employed a plank on the stationary fork lift to add an extra seating-perch in order to reach and troubleshoot the issue.  Photo attached of Sheila "surfing". 

TITLE: 02/04 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:  Lots of work towards finishing up in HAM1 and HAM7, including some surfing! LVEA is still LASER SAFE except behind the curtasins by HAM1/2 and at height.
LOG:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              

Fil, Rahul

Out of chamber investigation

This morning Fil and I unplugged Tip Tilt PM1 cable going to its Satamp and connected it to Tip Tilt JM3 and found no change in its Bosem counts (was still low for UL and UR, like before). We connected JM3 to PM1's electronics chain and it was looking good. We also checked the long grey cable and found it to be healthy. Thus we came to this conclusion that in-air electronics chain is healthy for PM1.

In-chamber investigation

During lunch time when the chamber was empty, I took the OLC of all four BOSEMs for PM1 and found their values to be lower by 20% (last taken in April 2025).

This tells me that either the in-vacuum cable is not working properly or all four Bosems are malfunctioning. I need more in-chamber time to further investigate this issue.

Closes FAMIS27833, last checked in alog88799

Values added to spreadsheet. 

WP13007 TW1 offload

Oli, Dave:

I started the offload process this morning. The first step is to freeze the past 6 months of raw minute trend data on TW1 and start writing current data to a new directory. While the copy is proceding, which takes 24 hours, NDS1 needs to serve the raw minutes from their temporary location. To this end, at 11:20 I reconfigured NDS1 daqdrc and restarted the rts-daqd.service. Oli recovered the control room FOM ndscopes after this restart.

The annual maintenance was done on the chillers at both End Stations this morning. 

Tue Feb 03 10:07:42 2026 INFO: Fill completed in 7min 39secs

Dave confirmed a good fill curbside.

Last Checked Jan6 (alog 88698).

NOTES:

• LAB2 looks OFF (noted last back in Sept)--will send a note to RyanC on this one.
• PSL 101 & 102 (0.5um particles) pretty much zero the last month, but do have 10min of 10 counts a couple times.
• DR1  (0.5um particles) also pretty much zero the last month, but has had some dust counts 3x in the last month.

TITLE: 02/03 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 10mph Gusts, 7mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.47 μm/s 
QUICK SUMMARY:

Reminder that the LVEA is LASER SAFE EXCEPT around HAM1/2 and at height.

Summary

We improved the IMC mode matching by repositioning JM2 and JM3 based on the calculation from yesterday. The mode mismatch was reduced from about 10% to ~2% after iterative alignment and mirror position optimization. Further improvement is expected with additional calculations and tuning, which will be continued tomorrow.

Details

We worked on improving the IMC mode matching following the calculation from yesterday. As a first step, JM2 was moved by approximately 3 inches; the new position is shown in the attached photos. The alignment to the IMC was performed using the newly placed iris in front of JAC_L2 and the iris after the output periscope, as described in the previous alog. By centering these two irises, the alignment could be brought to the level where IMC flashes were visible. From that point, adjusting JM3 allowed us to easily reach an alignment where the TEM10 content was at the ~10% level.

After achieving a reasonable alignment using a scratched mirror, we replaced it with a newly cleaned narrow-angle mirror for JM2. The scratched mirror was moved to JACR_M1. As a note, the scratch was oriented on the +y side; by keeping the beam closer to the −y side, the impact of the scratch was minimized.

With this configuration, the mode mismatch improved from about 10% to approximately 4%. Since the calculation suggested that further improvement should be possible, we continued tuning by adjusting the JM3 position. Based on the previous calculation indicating an offset in JM3, we first moved JM3 by about 1/2 inch in the −x direction (increasing the L1–L2 distance). This resulted in a degradation of the mode mismatch to about 6%. We then moved JM3 in the +x direction by a total of 1.5 inches (i.e., 1 inch further from the original position), effectively shortening the L1–L2 distance. With this adjustment, the mode mismatch recovered to approximately 2%.

We stopped the work at this point and plan to perform updated calculations tomorrow to guide the next iteration of tuning.

Used 1W into JAC.

9 (26.8dBm into EOM), 45 (27dBm) and 118MHz (10.76dBm) -> Used a single bounce beam from ITMX and scanned OMC. Successful for 9 and 45, nothing visible for 118. Detailed will be posted later.

24MHz (IMC, 14.2dBm) -> Scanned IMC length and tried to find something in IMC transmission. Nothing visible.

43MHz (JAC, 12.2dBm) -> Scanned JAC, saw nothing in JAC transmission. Boosted RF  power with an amp to 29.67dBm -> m=0.092. Without the amp modulation index would be 0.012.

Jennie W, Jason O, Masayuki N, Keita K, Jim W,

Summary: To check the function of the new EOM in chamber we made a measurement of the modulation indexes by locking the IMC and aligning the beam to AS_C with SR2. We couldn't get a good measurement of the sideband heights but this is probably due to the RF power being down by a factor of 100 from nominal. Will check with EE/Daniel on Monday.

First order of business was checking for stray beams at 100mW input power. Jason moved the BD we already placed for JM2 as we had moced this mirror position yesterday. We also put a new beam dump right after unused JAC port (output side there is tranismission through the curced mirror).

After this we turned the power up to 1W.

Lastly we found a stray beam exiting the table in the -Y direction, this was traced to the JAC REFL path. The REFL beam was hitting the side of a beam dump (near the -X side/PSL of the table) which is meant to cath a beam reflecting off the SEPTUM plate. This beam reflected off the beam dump causing a stray beam. We re-aligned the REFL path so the beam does not do this and instead bounces off the three REFL path steering mirrors and heads into a previously placed beam dump for this purpose on the -Y side of the table. This path will have to be re-aligned in order for the beam to get onto the IOT1 table.

No further stray beams were found so Jason de-energised the waveplate.

Photos to come.

After realising that the beam did not reach the AS_C,A and B QPDs yet we came to the control room to re-align to the output port. This is with the ITMY, PRM and SRM mirrors mis-aligned to allow us to mode scan the OMC in the 'single bounce' IFO configuration.

After Jim re-isolated HAM4,5 and 6 and BSC2 for us we were able to use SR2 to bring back the alignment to AS_C and then turn on the DC centering loops for AS_A and AS_B.

The OMC ASC did not work at first as the suspensions were railed. I cleared the ASC history, this did not help. We cleared the locking filter banks for OM1-3 and this unrailed the outputs and allowed us to turn on the OMC ASC.

We took an OMC scan at 1W input power, shown here. Roughly calibrated into MHz with the known FSR.

We cannot identify the 45MHz or 9MHz peaks, but after checking we realied that these RF driver powers were lowered 15 days ago. See image.

We will come back to this Monday.

Jason put back the rotation stage, locked it out and closed the light pipe.

J. Wright, J. Oberling

As part of WP 13006, we added another beam dump and moved one to ensure all stray beams that we could find were properly dumped.

We added the required beam dump on the unused output port of the JAC, to dump the unused beam here.  We also moved the beam dump that catches the leakage beam through JM2 so that it continues to dump this leakage beam in JM2's new location (needed to move JM2 as a result of EOM installation).  See the 2 attached pictures.

While scanning for other stray beams, I noticed a beam on the outside of the large beam dump that was temporarily relocated to the +X side of the new JAC input periscope.  This was traced to the JAC REFL path.  Turns out that when the REFL path was installed, the beam was erroneously reflected off of this beam dump on its way from JACR-M1 to JACR-M2.  To fix this we had to loosen the dog clamps for JACR-M1 and physically rotate it until the beam was centered on JACR-M2 (there wasn't enough range in the yaw actuator).  We then had to loosen and physically rotate JACR-M2 so that the REFL beam was once again captured in its temporary beam dump (dump located on the -Y side of the ISI).  Both mirrors were re-secured to the table.  Unfortunately, this means that we will have to revisit REFL path alignment to the new IOT1 table.

Today Rahul and I worked on reducing the last bit of clipping in HAM7.  The power budget shows a couple of percent more loss than we've expected previously, but I don't think we can improve it much right now so this is good enough. QPDA segment 3 is railed. 

This morning we found that we had some loss on B:L2, see Rahul's power budget alog as of lunchtime: 88971.  In hindsight, this was also possible in the power budget that Kar Meng reported before the suspension work this week, 88847. We translated the beam in the -Y direction in the SFI2 aperture, so it would make sense that we might need to translate the lens in the -Y direction.  However, there is no space to move it because the mount is already as close as it can be to SFI2 (photo).  So, we translated the beam using B:M3, using the power meter to judge when we were improving the alignment.  We found that this aperture is very small, there isn't much of a plateau where we aren't clipping.  

After doing what we could to reduce the yaw clipping here we did a careful power budget with the thorlabs power meter, we seem to have  8% loss to SQZT7, 11-14% loss from output of the OPO to the homodyne, which is a bit worse than past measurements ( 65066): 

• Opo 0.97-1mw
• Input to sfi1 0.97 mW
• Output sfi1 0.95 to 0.97 mW
• Hitting zm1 0.95 to 0.97 mW
• Return from filter cavity after sfi1 0.92 to 0.97 mW
• After BL1 0.93 mW
• Input to sfi2 0.92-0.94 mW
• Output from sfi2 0.91-0.92 mW
• After B:L2 0.86-0.91mW 
• After bm4 0.86-0.90 mW
• On the table bottom of the periscope 0.87-0.89 mW
• Before the homodyne 0.86 mW
• Refl power 24mW

We attempted to move B:M3 in pitch to see if we could reduce clipping on B:L2 that way, but that did not improve the transmission.  In pitch we also saw that we increased the clipping with small moves in either direction.  I will try to look up the beam size and aperture size next week to see if this makes sense.  

We adjusted B:B4 and ZM4 a bit to align onto the two irises on SQZT7. 

We also walked the two picomirrors used to center the FC QPDs, with the seed beam which saturates the diode.  From the control room I reduced the power and was able to mostly center, but it seems that QPDA segment three has been railed at 33.9 since November 29th.  

After we finished up, I went back to check the FCGS alignment onto SQZT7, which was not good, so I went back in for a few minutes to get that beam onto the filter cavity reflection diode.  I also had a look at the red + green co-alignment, which looks similar to what Kar Meng posted in 88859.  

We also checked that the new cable routing doesn't block the beam onto H:PD1, we couldn't see the beam but we think it looks like a clear path.  Rahul also took a photo of where the beam exits SFI2.