Checked the baffles for the CRS on the constructed unit, everything fit fine. Spent time doing alignment for the other two constructed HoQIs. 01-SN008 aligned with 87% fringe visibility, this required the retroreflector on the baseplate to be rotated a bit as it wasn't quite in the correct position. 01-SN007 spent a long time trying to align (this was also worked on the other day with limited success), couldn't get above 60% FV so we decided to take it apart and redo it with the dowel pins in place. After taking it apart we found that the QWP was damaged by the metal screw, honestly quite impressive that it was still seeing 60% FV! See photos. The sin PD cable is also damaged and will need to be fixed before we use this HoQI. Assembled the remaining HoQIs including the dowel pins. Need to clean the final HWPs to finish this assembly. Additionally, 01-SN006 has no PDs as it is using the faulty assembly from before, 02-SN006 connector needs to be flipped. Current HoQI status: 2 aligned on CRS, 1 aligned, 2 with faults, 3 (mostly) constructed waiting to be aligned. pic 1 - broken sin pd pic 2 - broken QWP pic 3 - serial number for broken sin pd assembly
A set of spare cables was fabricated and will be sent to replace the one mentioned here, and the one mentioned in this alog: 90495
Shipping FRS: https://services1.ligo-la.caltech.edu/FRS/show_bug.cgi?id=38287
J. Oberling, R. Crouch
Yesterday we measured the initial position of the BBSS in the WBSC2 chamber, results shown in the 1st picture. Our goal is to match the position deviations we had on the test stand for the BBS SUS cage, as that was the SUS cage position we aligned the BBS optic with; all alignment moves after the SUS cage were positioned were done with the SUS chain itself, the cage did not move again, so matching the cage deviations should correctly position the BBS optic. As a reminder, the test stand deviations are shown in the 2nd attachment.
Based on this we will move the cartridge assembly with HEPI by approximately +2.5 mm along the X axis, +0.5 mm along the Y axis, and a CW rotation of ~500 µrad.
Shiela, Begum, Camilla, Madi E2600157
Morning:
Starting at FC alignment from Friday, 90527.
Tried to make the beam the correct ~5.5” height at ZM2 with A:M1 and then use ZM2 to get correct height at ZM3 (~6.25") but ZM2 did not have enough range. We railed it by only going halfway. Instead, we used A:M3 for beam height at ZM3 and then ZM3 for retroreflected beam. Did this only in PITCH (used YAW offset to help check retro-refection). Took height measurements (~6.25" at FC1 and ZM3, 5.85") This is not perfect at ZM2 but we'll check for any astigmatism when beam profiling. Attached alignments.
Tried to use B:M1 and BM4 to realign to ZM4 iris. However, beam could not be near centered on B:L1 aperture and fully transmit SFI2 (was a clipped after SFI2).
Realized beam height wasn’t level after OPO. High at A:L1 and low at A:DC2. We then used A:M1 pitch to center art A:L1 and then SFI1 aperture. And A:M2 to center on A:L2 aperture. We again checked if we could now get the correct height at ZM2 without railing ZM2 to get bean to ZM3, no. So adjusted A:M3 in PIT. After this was done, we realized PIT and YAW must be cross coupled as the beam was yaw'ed towards +X at the ZM3 iris. Paused.
Afternoon:
Looked again at the beam through A:L2 aperture and Sheila thought it was high. Begum and I then counted turns of the A:M1 and A:M2 mirror knobs before the beam clipped on the SFI1 and A:L2 apertures (checked that's where it was clipping with power meter) and then centered on each aperture.
Once we were happy with this. We again used A:M3 for beam height at ZM3 and then ZM3 for retroreflected beam. Did this only in PITCH (used YAW offset to help check retro-refection). The beam is still off in yaw at the ZM1 iris. Think this is from our initial A:M1 and A:M2 PIT moves.
We weren't 100% happy with our height measurements as think the beam was a little low at ZM3 <6.25", ZM2 5.8", FC1 6.25". We also think that the beam isn't centered on ZM2, photo. Another reason to think this is that when we try to move the retrofection to each side of the outgoing beam, it only moves to one side.
Beam scans:
We then stopped alignments to think about what to do with yaw and took beam profile measurement before and after ZM2 with the Phasics camera and TCS FLIR laptop. Took profiles and three locations between ZM1-ZM2 and two locations ZM2-ZM3. In one of the locations between ZM2-ZM3 we adjusted the ZM2 PSAMS from 3.15V (nominal) to 1.15V (minimum), 6.05V (maximum) and 4.51V (somewhere else in the middle).
TITLE: 06/09 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: 28mph Gusts, 21mph 3min avg
Primary useism: 0.06 μm/s
Secondary useism: 0.19 μm/s
QUICK SUMMARY:
BBSS in-chamber + SEI work is in full swing, ITMy in-chamber First Contacting this morning, ISS PD Array alignment continues, CRS work continues, HAM7 in-chamber work for SQZ, and SPI is on deck at HAM3. CEBEX has brick walls which look over 10'.
Have had a windy morning with starting at around 2am locally and gusts up to 45mph.
Today:
Up next:
Start HEPI spring loading, recheck FARO shots, move per what FARO says we need to move
Suspend the BBSS, take Top TFs, then work on M2 and M3 stage OSEMs.
Erik V, Jennie W, Tony S
Summary: Jeff and I need a solution for SPI installation in order to communicate offsite to team members about alignment. Erik and Tony found a solution using the Blueman application. Just now we have this working on
TITLE: 06/08 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:
ISS PD Array alignment continued, ITMy First Contact prep (for 3hr First-Contact-ing tomorrow), some FARO work for BBSS, cabling in BSC2, etc.
LOG:
J. Kissel, F. Clara WP:13296 %%%%%%%%%%%%%%% Executive Summary: Following up after last week's completion of SUS-R2 (LHO:90500), all HAM3 in-air electronics cables and optical fiber patch cords to/from SUS-R2 or TCSY to the chamber have been "pulled," i.e. routed fully to each end of their connections. This leaves *only* the HAM2 ISIJ QPD connection to its transimpedance amplifier in SUS-R1 as the last cable to be landed in the ex-vacuo part of the SPI electronics wiring and optical fiber network. %%%%%%%%%%%%%%% Details Here's the status summary of each of the HAM3 cables and patch cords Fil and I pulled today. SPI Picomotor Cable SPI_HAM3_013 Description :: This cable connects drive CHs 5, 6, 7, and 8 of the TCSY / CO2Y Picomotor Controller "G" (driven by Corner 2 ECAT Chassis) to the HAM3 D6 12x D25 feedthru into port F11. Status :: Now connected at controller and at flange. Strain relief at flange is not yet final. SPI PD Concentrator Cable SPI_HAM3_015 Description :: This cable bus routes the SPI HAM3 ISIK Transceiver PD and QPD signals (IFO_REF_A, IFO_REF_B, IFO_MEAS_A, FBR_PWRIN_REF, FBR_PWRIN_MEAS, IFO_MEAS_B, QPDB_Q1, QPDB_Q2, QPDB_Q3, QPDB_Q4) from HAM3 D6 port F10 to the "PD Input" port of the S2500712 D1002481-v4 "Variant 2" of the SPI transimpedance amplifier (TIA) chassis in SUS-R2 U4. Status :: Now connected at TIA and at flange. Strain relief at flange is not yet final. SPI_PSL_001 Optical Fiber Patch Cord Description :: This optical fiber patch cord connects the fiber collimator SPI-FC1 fiber output of the SPI Pick-off Path in the PSL to the "PSL IN" fiber input port on the front-panel of S2500058 D2400156 SPI Laser Prep Chassis in SUS-R2 U6+U7. Status :: NOT ENERGIZED (thanks to newly installed Uniblitz Shutter; LHO:90490). BUT -- shielded with standard orange protective tubing and now brought down from the cable tray (2nd story of "high" tray running above the input arm) and landed at the Laser Prep Chassis. Neither strain relief nor routing through rack is final. SPI_REF_001 and SPI_MEAS_001 Optical Fiber Patch Cords Description :: This pair of optical fiber patch cords connect the modulated at 80.0 MHz [MEAS] and (80.0 MHz - 4096 Hz) = 79.995904 MHz = "80- MHz" [REF] light from the SUS-R2 U6+7 Laser Prep Chassis fiber output ports to the HAM3 D4-1J1 [S3228003 MEAS] and D4-1J2 [S3228002 REF] fiber feedthrus (D2500175). Status :: NOT ENERGIZED (no laser input from PSL, nor are the AOMs being driven with any RF). BUT -- shielded with standard orange protective tubing and routed in the "low" cable tray system that runs from SUS-R2 to the feedthrus underneath the -X side of the chamber. They're connected at the SUS-R2 U6+7 Laser Prep Chassis fiber output ports, but they're dangling at the feedthru end because we haven't finished upgrading the feedthrus (see LHO:90511). References The SPI Pathfinder has been integrated into lots of different subsystems, so there's a ton of disparate systems drawings that are need to follow its signals from "soup to nuts." Optical Fiber [1] D1300348 As-built PSL/IO Table Layout [2] D2400110 Optical Fiber Routing Diagram RF electronics and PD Electronics [3] D2400111 SPI Wiring Diagram [4] D1002874 HAM3 Flange Layout [5] G2401479 Systems-level Slides for HAM3D4_12xD25 and HAM3D6_FiberFeedthru plans [6] SUS-R2 Rack Layout w.r.t. SPI [7] E1100591 (Heliax) RF Signal Distribution System Picomotor Drive [8] E1100892 TCS Wiring Diagram [9] D1900511 ISC Wiring Diagram [10] D1100683 EtherCAT (Beckhoff) System Diagram [11] E1200072 Picomotor Channel Inventory [[Very-out-of-date -- see unresolved IIET:32610]]
Pictures of SPI Picomotor Cable SPI_HAM3_013
Pictures of SPI PD Concentrator Cable SPI_HAM3_015.
Pictures of SPI_PSL_001 Optical Fiber Patch Cord, SPI_REF_001 and SPI_MEAS_001 Optical Fiber Patch Cords
Ibrahim, Anamaria
This morning we:
- set up the FC fabric on the drum;
- lowered the ITMX ACB to take its wedge, and then used it to swing the ITMY ACB out of the way;
- inserted the peek "Kurt fingers" between ITMY and its CP in preparation for installing the FC jig this afternoon.
This afternoon we:
- set up the jig around the test mass;
- tightened the drum with the fabric onto the test mass while watching the fibers on camera;
- added the grid+mesh for pressing, as well as picos on the ring of the drum;
- added the funnel and hose setup, connected to the spigot.
We will add more details and photos later. For now we are dumping photos in the common FC google drive. Folders named by date and activity.
First attachment shows that the ISS array PDs suddenly lost the beam (bottom left) right after the IM1 LL OSEM jumped (top left) on Friday, meaning that the problem was not just the OSEM sensing, somehow the alignment was affected by this.
This morning Rahul physically inspected IM1 and checked cables and electronics but nothing was wrong. He pulled the LL OSEM and nothing was wrong either. He put it back on, centered the OSEM depth (only for LL) and everything looked normal.
We locked JAC and suddenly we got the flashes on ISS array back, see the second attachment.
Though this is good, it's also frustrating that we don't understand what happened. My theory is that somehow something (OSEM bobbin thing?) was charged and pulled the closest metal electrostatically, changing the DC alignment.
We'll see if we can center REFL ASC sensors as well as ISS QPD. If we can, we'll proceed to close out.
FYI, following is the IM1 OSEMINF before the jump, right after the jump and now. UR experienced 500 counts jump and clearly got back after Rahul's job. Changes for UL and LR were much smaller but they got closer to the pre-jump position, too. Don't pay much attention to the 1000 counts difference for LL now VS pre-jump because it was reset.
| Before the jump on Friday | After the jump on Friday | After Rahul reset the OSEM | |
| UL | 16647 | 16577 | 16695 |
| LL | 9032 | 2492 | 10709 |
| UR | 14790 | 15292 | 14798 |
| LR | 7154 | 7022 | 7169 |
To investigate the issue on IM1 (LL AOSEM inmons dropped to 2000 counts from 9k approximately) I did the following things,
1. In HAM2 chamber, at first I thoroughly inspected IM1 for any signs of rubbing - found none and the pendulum looked free. The suspension was set to SAFE state during this time.
2. Unplugged LL AOSEM and connected healthy UL AOSEM cable to check for inmons - was still reading 2k. Hence, this ruled out any issue with LL in vacuum cable.
3. Took the AOSEM out of the suspension, visually inspected the LED and PD - looked all healthy. I also inspected the magnet on the optics for any damage - found none, everything looked fine.
4. As a backup I had spare AOSEM in hand for replacement.
5. I took open light counts of the LL AOSEM (now that it was plugged out of IM1) - the reading shows 19k counts which was good. This meant that there was nothing wrong with the LL AOSEM or the electronics chain.
6. I plugged that LL AOSEM back into IM1 and centered the flag/magnet to around 10k counts (50% open light).
7. Took chamber side transfer function measurements - all three dof. looked healthy, peaks and magnitude were good. The coherence was not so great due to the noisy environment.
Then I declared that IM1 is healthy and back in action.
What could have happened? - I think the flag magnet on LL could have been faintly touching or stuck and then set free, thus leading to a sudden drop in the inmon values. The second theory is that the AOSEM itself moved very slightly - its only held by a single set screw and does not have rails for moving them in and out.
TITLE: 06/08 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: 3mph Gusts, 1mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.08 μm/s
QUICK SUMMARY:
Lots of items today: Continue finishing up ISS PD Array aligningment (then ground loop checks?), HAM3 SPI cabling/flange work + SPI main install, FARO for BBSS around HAM3, ITMy First Contact in-situ, HAM7 in-chamber.
Big M7.8 EQ ~15hrs ago (nothing tripped...although we have lots of SEI +SUS down for in-chamber work).
CEBEX crew continues laying brick (seeing about wall of 5-7 brick high this morning).
Friday June 5th we completed the assembly for the CRS that is going in HAM3. First thing we checked the alignment of the HoQIs, Fringe visibility: SN005 86% SN007 85% We swapped out the photodiodes and cables in SN007 due to damage in one of the cables which meant the wire was exposed risking grounding issues should this touch any of the metal parts. The fringe visibility after this was at 72%. The HoQIs were completed with the baffles and top cover. SN007 cover is incorrect and the correct parts were not out of C&B so the wrong cover is on it at the moment this will be switched when we have the clean part. They were fixed to the CRS and aligned to it. SN007 is on the right and SN005 is on the left. Fringe visibility with the CRS fixed was as follows SN007 sin 82% cos 80% mcos 82% SN 005 sin 83% cos 75% mcos 83% The CRS was released and the fringe visibility for both left and right was checked, they were >80%, not all PDs were recorded but eg SN007 mcos was 82%
(Gerardo M., Brandon P. (RMC Tech), Jordan V. (buddy))
Today the second oil pump was replaced on the Kobelco unit, no issues to report. For previous work see aLOG 90318.
The purge air was isolated at the dryer towers and at the point of delivery before starting work. Brandon shut off the compressor and stopped the dryer system, then removed and replaced the oil pump. Kobelco compressor was re-started, oil measured, compressor was turned off to add oil up to nominal value, then the compressor was started and load tested. No issues noted. Brandon handed over the system. I started the dryer towers back up, no issues noted. Dew point from the local reading at the towers remained below -51 oC since the dryer system remained with both towers "loaded", and since there was no demand both remained pressurized. After an hour with both the compressor and the dryer towers running at nominal, I opened the purge air to the LVEA lines. After 45 minutes I took a couple of measurements.
Measurement results:
Purge air is purging into the opened volumes. Once again, please don't waste the purge air, if you can please keep those C3 door covers closed. Thank you!
Leaving site now.
RM2 was nicely relieved by rotating IM1 in YAW, ASC REFL sensors were centered, RM2 only used 40% of DAC range, people==happy (ASC-REFL-centered-20260605.png).
ISS QPD was nicely centered, it was easy, people==happy (iss_CENTERED.png).
Then suddenly we found that the IFO REFL beam is clipped at the bottom of the IFO REFL baffle, ISS array was totally out of whack, forward-going beam from IM2 was not centered on the retroreflection check iris between IFI input baffle and IFI HWP baffle, people!=happy.
Turns out that something bad happened to IM1 about 10 minutes after ISS was centered (IM1_bad.png). Without any change in the drive, H1:SUS-IM1_M1_OSEMINF_LL jumped by negative 172 counts causing apparent positive 1570urad jump in DAMP_P and DAMP_Y. UR changed by 12 counts, which is like O(100urad) type change.
This doesn't necessarily mean that IM1 moved that much, maybe one OSEM was bumped while we're trying to put the cover on the ISS, but the thing is that this must have caused physical rotation somehow because we see the beam moved downstream of IM1.
We tried to diagnose the IM1 but found no obvious touching, transfer functions didn't look wrong, EQ stops have gaps, magnets look as if they're OK.
You don't have to read further, below is our memo to remember what was done.
We've made another YAW move (of positive 300urad) for IM1, i.e. [P,Y]=[517, -687] -> [517, -387] to relieve RM2 further.
Based on calculation, also moved IM2 and IM3 to roughly align things. IM2 [P,Y]=[0, -588.7] -> [0, -19] IM3 [P,Y]=[35.3, -415] -> [35.3, -86].
Checked the IFI output baffle and noticed that it seems to have an offset in -X direction relative to DKDP baffle. The beam was well centered on DKDP baffle, but was too much in +X direction on the IFI output baffle.
Moving IM2 further, [P,Y]=[35.3, 381] to split the difference. Distance between the forward-going beam and the parking beamdump pickoff was ok.
This resulted in large IM3 Yaw step (IM3 [P, Y] = [35, 654]) to bring the beam close to the nominal position in front of PRM. Horizontally, the beam was off by 0.5+-1mm in negative Y direction. Nominal beam height at the measurement point for PRM 159.05mm. Measured 157.1+-1mm.
IM4 Yaw moved by positive 350 ([IM4 [P,Y]=[761, -205]) to set the beam position in front of PR2. Horizontally, the beam was off by 0.5+-2mm in positive Y direction. Nominal beam height at the measurement point for PR2 168.56mm, measured 169.8+-2mm.
Centered the retro-reflection check iris to the forward-going beam between IFI input and IFI HWP baffle. Aligned PRM to center back-propagation on that iris.
PRM [P, Y] = [-1185, -270].
Centered refl asc sensors. This worked really well, RM2 DAC was only using 40% of its range after centering ASC REFL sensors. Even though this was one attempt, I'm comfortable enough to say that we'll be fine.
Moved on to center ISS array. We removed the ISS array cover from the assembly to use the input aperture tool to make things easier. Large hole aperture as well as medium was used, didn't bother to use the small aperture. We used two pico mirrors (had to use hand because no driver is connected until the IOT2L is back). Iteration between two mirrors was easy and the centering was done by 22:37 UTC.
RM1 P, Y = -196, 209 (13% of DAC range)
RM2 P, Y = 609, -602 (40% of DAC range)
Happily we put the ISS array cover back on. Unknown to us, something happened to IM1 at around 22:46 UTC.
Remaining task:
solve IM1 mystery?
shoot the pic of pico mirrors to see how much range we have.
center IM4_TRANS
take aperture photo for IFI inpjt and IM4 baffle, recenter IM4 baffle if necessary.
ground check.
I post this picture showing the separate osem trends for IM1 and also the CPS Z and RX motion of the chamber. The big step in LL IM1 osem was coincidental with noise in Z and RX of HAM2 ISI so we think it was when we were leaning into the chamber to p6ut the cover on the ISS. Later on there is a step change in the Z and RX motion, I think this was when Rahul actually stepped into chamber to screw the cover screws down. I conclude that whatever happened was when we were leaning past the IM1 from outside the chamber.
I ran the rubbing scripts from this LHO alog #77383 for IM1 but wasn't sure how to interpret the results, reference time was midnight last night. The only one that looks really different is the yaw degree of freedom.
Annamaria drove some signals through each IM1 OSEM in turn to check for rubbing.
Time of test 02:00 UTC
| Response in each OSEM | UL push | UR push | LL push | LR push |
|---|---|---|---|---|
| UL | 17.7 | 0.6 | 8 | 10 |
| UR | 0.4 | 17 | 10.7 | 7 |
| LL | 6.6 | 7.5 | 15 | 1 |
| LR | 11 | 8 | 1 | 18 |
We used an actuation of 60000 counts offset added ther the COILOUT filter bank. We can't see any obvious imbalance in the response of the four osems.
Annamaria also ran an undamped TF in pitch, shown here compared to a reference measurement from 2024. This doesn't really seem to show any obvious rubbing.
Summary: As Keita said above we are confused as to what exactly is wrong with IM1.
Begum, Ryosuke, Camilla, Madi
Summary: Were able to retroflect the beam off FC1 (when placed at O4 sliders) with ZM2 and ZM3 but the beam height is incorrect, as expected, VOPO optics will need to be moved to fix this.
Attached alignment for good alignment towards IFO, on ZM4 iris and SQZT7 IR PD irises. Both when OPOs is unlcoked and locked. When OPOS is locked beam doesn't go though closed irirses so isn't perfectly aligned but it is close enough.
Our Friday's alignment for FC retrorefection (with non-ideal) beam height: