Robert, Dave:
h1pemex was changed, the newly installed AMON subsystem which reads the current to ground signal now drives the 4th channel of the 20bit-DAC via the GDS_3/DACOUTF_3 filter module chain.
h1pemey was modified to fix a typo I had made to the DACOUTF_3 filtermodules, it was missing the underscore.
Both models were restarted at 15:55, followed by a DAQ restart at 16:01-16:06
I created MEDMs for the new DAC drive system. I'll work with Ryan S on integrating this with his "GDS DAC DRIVE" screen, currently I've added buttons to the bottom of Ryan's MEDM to open mine.
TITLE: 02/12 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: Dave did some CDS restarts early in the day, alog89133, and alog89130 and again at the end of the day. Secondary microseism has gone up quite a lot in the past 9 hours, presumably from the 10.5m (windy.com) waves crashing into the Juneau/Ketchikan area north of Washington state. VAC team left an AUX cart pumping down by HAM4. HAM1 alignment and EOM crystal work continued today.
LOG:
| Start Time | System | Name | Location | Lazer_Haz | Task | Time End |
|---|---|---|---|---|---|---|
| 22:49 | SAF | LVEA is Laser SAFE | LVEA | NO* | LVEA is Laser SAFE *BIFURCATED HAM1/2 | 16:49 |
| 16:17 | FAC | Kim | LVEA | N* | Tech clean | 17:51 |
| 17:14 | EE | Marc, FIl | MSR, Mez, LVEA | N* | Cable pulling for BHD | 00:01 |
| 17:18 | FAC | Mitch | LVEA | N* | Checks | 17:35 |
| 17:22 | FAC | Richard | LVEA | N* | BSC2, HAM3/4 area checks | 17:35 |
| 17:24 | ISC | Jason | LVEA | Y | HAM1 JAC work | 18:50 |
| 17:27 | ISC | Keita | LVEA | Y | HAM1 | 18:55 |
| 17:33 | ISC | Jennie | LVEA | Y | HAM1 work | 20:08 |
| 17:58 | FAC | Randy | LVEA | N* | Talk to Fil and Marc | 19:02 |
| 18:14 | FAC | Richard | LVEA | N | BSCs 1,2,3 checks | 18:50 |
| 18:15 | FAC | Kim | EndY | N | Restock garb | 18:15 |
| 18:39 | ISC | Betsy | Optics lab then HAM1 | N, Y | Check in with crew, parts dropoff | 20:08 |
| 18:53 | VAC | Gerardo, Jordan | HAM4/5 | N* | Swap ion pump, Gerardo out at 1930 back in 2000 | 20:18 |
| 18:55 | ISC | Camilla | LVEA | Y | HAM1 | 20:04 |
| 18:56 | ISC | Keita, Elenna | Optics lab | N | EOM, Keita out 2022 | 20:20 |
| 18:56 | ISC | Camilla | Optics lab | N | eom | 18:56 |
| 19:34 | VAC | Travis | LVEA | N* | Talk to VAC crew | 19:43 |
| 19:53 | VAC | Travis | LVEA | Y | Help swap pump | 20:18 |
| 21:02 | FAC | Randy | LVEA | N* | BSC2 platform work, height laser hazard | 21:40 |
| 21:04 | ISC | Keita, Elenna | Optics lab | N | EOM | 23:00 |
| 21:29 | VAC | Jordan | LVEA | Y | HAM4/5 pump work | 22:32 |
| 21:31 | VAC | Gerardo | LVEA | Y | Join Jordan | 22:32 |
| 21:44 | SQZ | Camilla | LVEA | N* | SQZ bay | 22:00 |
| 22:05 | ISC | Jason, Jennie | LVEA | Y | HAM1 work, Jennie out 23:30 | Ongoing |
| 22:20 | SQZ | Sheila, Camilla | Optics lab | N | Checks, Sheila out at 23:08 | 23:35 |
| 22:34 | PEM | Robert | EndX | N | Ground work, back to CS at 00:00 then back out | Ongoing |
| 22:36 | ISC | Betsy | Optics lab, HAM1 | N/Y | Parts, help teams out | 23:55 |
| 23:00 | ISC | Keita, Elenna | LVEA | Y | HAM1 in at 23:00, Elenna out 00:22 | 01:09 |
Jennie W, Jason O, Keita K, Betsy W, Camilla C
Summary: EOM alignment and position captured, moved to opics lab for crystal replacment, JAC-REFL path alignment in progress.
This morning Jason, Keita and I checked the centering of the HAM1 irises after the JM3 alignment Olli and I did on Tuesday. We didn't move the irises right after JM3 as this seemed centred. We did reposition the iris right before the HAM2 septum plate in x and y.
This, along with the alignment of the IMC Olli, Jenne and I did on Tuesday, captures where the beam was with the current EOM installed.
Keita marked the EOM base position with a dog clamp and removed it to the optics lab for crystal replacement. The shims for the EOM and the screws that hold it to the table are in a foil packet on the +Y - X HEPI pier.
Betsy, Camilla and I rechecked the REFL path and spent some time moving JACR-M2 to centre it on the incoming and outgoing beams. Then we pitched down this mirror so the outgoing beam hit the upper periscope mirror. After this Betsy had some concerns that we were too close to where the JM3 tip-tilt will sit (we are currently using a siskiyou mount for this mirror). So we yawed the JACR-M2 mirror so the beam hits the viewport slighly more to the right (as viewed from -Y side). Looking at the placement on the viewport simulator, the beam is low and right on the viewport, whereas it comes to the table, high and right in the bellows hole. This table it almost at the top of its adjustment range, so Jason and I plan to go in this afternoon and see it we can move up the table feet so the beam can move up in the viewport a bit. Betsy and I measured the tilt of the beaM from JACR_M2 off the table. The heigh is 103 mm at the table hole 8 inches from the -X edge and 8 inches from the +Y edge. It tilts up to 113mm at the last hole in this row on the -Y side.
Betsy and I also checked the pitch of the beam entering and leaving JAC after the EOM was removed. The input beam to the JAC was 102 mm above the table, the output beam before the L1 lens was the same height, and the beam height just before JAC_M3 was also 102mm. There is not a large distance between the JAC and JAC_M3 steering mirror so it is hard to get a good measurement of any small pitch in the beam. Pictures for this alog are coming.
EOM crystal was swapped, EOM was tuned in the lab and put back in place in HAM1. Tuning is good. First look at the beam looks good, no ghosts.
We extracted the EOM from HAM1 after the position of the EOM base was marked with three dog clamps.
In the lab, the EOM pivot plate was separated from the EOM base (which was a major pain again), then the EOM top structure was separated from the pivot plate.
Before unmounting the old crystal, three set scews in the face plate were screwed in to contact the electrode board, and then very slightly backed off. After this, we lifted the board/side assy from the front plate to expose the crystal on top of the face plate, swapped the crystal (in our setup, the distance between the crystal edge and the front plate edge close to the output side was set to ~7.5mm due to 0.5mm shim washer we use between the front plate and the input side plate), and put the board/side assy on. This was much easier than before due to the aforementioned set screws. Elenna will post some pictures.
In the afternoon the EOM was tuned in the lab and put back into HAM1. We didn't bother to tap things around this time.
EOM was transferred to HAM1. Tuning measurement was repeated in chamber, no big change from the lab measurement and they're good (see pictures).
With EOM in place, we locked JAC and confirmed that the wedge orientation of the crystal was correct (because the beam was mostly deflected in YAW toward +Y direction). We also saw that the beam deflection was different from the old EOM in PIT as well as YAW (more difference in PIT according to Jason).
No fine alignment of the EOM was done for today, but we quickly raised the power to 1W and neither Jason nor I were able to find any clear ghost beams, unlike with the old crystal.
Below is a table of RTP crystals at LHO (see alog 89125, alog 89115).
| RTP crystal S/N, batch | Status |
| 10252007, Old | Good, in HAM1 |
| 10252003, Old | Chipped. Probably never used. |
| B1913109, New | Uninstalled, ghost beams |
| B1913108, New | Never used, ghost beams |
Jennie W, Jason O, Tony S, Olli P
Yesterday we put the viewport simulator on the -Y door of HAM1 to enable us to check the JAC REFL path, we had to move the in-vac mirrors for this path a couple weeks ago because the beam hit the side of a beam dump before hitting the second steering mirror after the JAC input coupler and so was mis-aligned.
The viewport simulator has tape marking the centre of the real viewport for this beam that was put in last time we had it up on this door.
We also rolled up the IOT1 table and plugged it in.
We had to move the table in -x direction from its ground markings as the periscope was too far right in the relative to the bellows hole and the viewport simulator, we also moved JACR-M1 as it was one row of holes too far in plus x direction.
The beam hit too high on the periscope, so it was missing the mirror by an inch, this will need to be corrected with pitch on the in-vac steering mirrors.
Pictures of the JACR-M1 move. First is the mirror position before the move, second is after the move, and third is a zoomed out view showing the input area of the JAC (temporary JM1 to be replaced with a tip-tilt suspension, JACR-M1, and JACR-M2).
Closes FAMIS#39854, last checked alog88973.
MR_FAN4_170_1 had a slight noise increase a little over a day ago, MR_FAN2_170_{1,2} are both seeing lots of spikes.
The EX fans all increased in noise around 15:30 UTC this morning.
Today Randy T and I ran power for the Cross Flow HEPA fans on the platform around BSC2. The fans are on and turned down to low at the moment. We also moved the dust monitor from the floor to the platform to monitor dust counts to have a better understanding before pulling the dome.
Thu Feb 12 10:13:15 2026 INFO: Fill completed in 13min 11secs
Travis confirmed a good fill curbside. He removed an ice ball from the end of the discharge line pipe.
Dave, EJ, Ryan C.
Following the h1pemey install this morning I realized that this was the only model on h1iscey built against the latest RCG5.5.2 (all others were still at 5.5.0).
With Ryan's permission I rebuild h1iopiscey, h1iscey, h1caley, h1alsey with rev-lock to ensure identical software using RCG5.5.2 and restarted all the models at 09:41.
No DAQ restart was required.
WP13027, WP13029
Robert, Ryan C, Dave:
I installed new h1pem[cs, ex, ey] models this morning. Changes are:
. OSC+NOISE_GEN signal-injection section for DAC drives
. New AMON ground current monitor signals
. Fix GDS_n indexing at end stations
Note that the temporary "ADC" channel names for the ground current monitor could not be removed because they are being sent by the DAQ Broadcaster to GDS. These should be either changed to the new names (and CS added), or they should be removed.
| EX | H1:PEM-EX_ADC_0_09_OUT_DQ |
| EY | H1:PEM-EY_ADC_0_14_OUT_DQ |
A DAQ restart was required. This generally went OK, but FW0 restarted itself after running about 8 minutes.
In the event MER in-rack work causes issues with h1sush7 SWWD, I have bypassed h1seih7 SWWD for the duration of the work.
The vane position of the fan inside air handler 1 at End X was changed from 100% to 70% in order to increase the airflow through the fan. This was changed to more closely match the settings at End Y. End Y temperature trending has been consistent while End X has had moderate variation in comparison.
TITLE: 02/12 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: 3mph Gusts, 1mph 3min avg
Primary useism: 0.05 μm/s
Secondary useism: 0.28 μm/s
QUICK SUMMARY:
TITLE: 02/12 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: HAM1 work continues, HAM7 is pumping down.
LOG:
| Start Time | System | Name | Location | Lazer_Haz | Task | Time End |
|---|---|---|---|---|---|---|
| 22:49 | SAF | LVEA is Laser SAFE | LVEA | NO* | LVEA is Laser SAFE *BIFURCATED HAM1/2 | 16:49 |
| 16:10 | FAC | Kim | LVEA | N* | Tech clean | 17:30 |
| 17:10 | SQZ | Keita | Optics lab | LOCAL | EOM | 19:15 |
| 17:17 | EE | Marc, Fil | LVEA, CER | N* | Pulling cables | 00:46 |
| 17:28 | FAC | Mitch | LVEA | N | Checks, WEST BAY | 17:46 |
| 17:30 | FAC | Kim | EndX | N | Tech clean | 18:48 |
| 17:40 | ISC | Betsy | LVEA | N* | Parts | 17:48 |
| 17:49 | SQZ | Betsy | Optics lab | LOCAL | Join Keita | 19:15 |
| 17:54 | ISC | Camilla | LVEA | N* | Bring out dog clamps | 18:49 |
| 17:59 | SQZ | Elenna | Optics lab | LOCAL | Join Keita | 19:15 |
| 18:06 | FAC | Randy | LVEA | N /Y | BSC2 tent, at height hazard | 18:24 |
| 19:01 | ISC | Jason, Oli, Jennie | LVEA | Y | HAM1, refl path, Viewport simulator | 20:00 |
| 19:21 | FAC | Eric | EndX | N | Chiller yard checks | 19:35 |
| 21:20 | SQZ | Keita | Optics lab | LOCAL | EOM? | 23:32 |
| 21:33 | ISC | Jason, Jennie, Tony | LVEA | Y | HAM1 work, refl alignment | ongoing |
| 21:59 | VAC | Gerardo, Jordan | LVEA | N* | HAM4 annulus ion work, height laser hazard | 23:16 |
| 22:14 | FAC | Mitch | LVEA | N | West bay checks | 23:09 |
| 22:26 | FAC | Richard | LVEA | N* | Safety checks | 22:50 |
| 22:35 | SQZ | Betsy | Optics lab | LOCAL | Join Keita | 23:36 |
| 00:29 | ISC | Betsy | LVEA | Y | HAM1 | Ongoing |
18:15 UTC HAM7 SEI SW watchdog trip from a H7 crash, FE & ADC errors on IOPSUSH7 SUSFC1, SUSSQZIN SUSAUXH7, IPC and DK error on SEIH7.
Dave restarted everything ~20 minutes later
Following alog 89115, we found that the old batch crystal from that alog (S/N10252003) had a big chip at one corner. It is pretty bad we don't want to use that.
Betsy found another old batch (S/N10252007, "inspected 12/21/11" and UF tag dated 4/21/09), so we A-B-ed that one with the spare new batch (S/N B1913108).
The beam path was made as level as possible at 3" height using a beam leveling tool (a black metal thing with a tiny aperture at each inch of height).
We put the crystal on a platform that is roughly 2" 29/32 (which is about 2.4mm lower than 3"). The crystal is 4x4x40mm so that's about the right height.
We spent some time to make YAW alignment as good as we can for each of the crystals.
We scanned the beam in PIT from top to bottom (or bottom to top), each extreme is where the beam is almost clipped (but not actually clipped) by the top or the bottom face of the crystal.
Look at the attached, the new batch (left column) clearly shows multiple beams even though the focus is not as sharp as the old batch photos. As we misalign in PIT, the dark place moves relative to the main beam and the contrast changes too, but multiple ghost never went away. At the extrema (very close to the top or bottom edge) it looked as if the beam is better but I'm not sure it actually was.
The old batch (right) didn't show such a behavior. The beam shows something like a diffraction pattern but no separate ghost beams. Everything moved with the main beam. Not sure if the diffraction pattern came from the aluminum surface or EOM, but clearly this is MUCH better than the new batch.
Note, due to the apparatus (the steering mirror is 20" upstream of the EOM), we haven't searched in a huge PIT angle space, it's actually roughly +-4mrad or so, the angle is not negligible but it's more parallel displacement scan than an angle scan.
Also note, when the crystal was put in place it seems that there's some vertical deflection which was different for the old and the new. On the top two pictures, there's no change in the input alignment into the crystal.
Based on this observation, I'd say using the old batch makes sense. LHO people (Jennie, Rahul, Betsy and myself) had a brief conversation with Masayuki and MichaelL and we all agreed that that's the way to go.
Attached is the picture of the chip on the spare "older" crystal S/N10252003 The other picture shows the box labels of the EOM crystals and stat at LHO, namely: 10252003 chipped 10252007 to be swapped into the JAC EOM 2 newer ones which are having some scatter issues as Keita has written about
Jennie W, Jason O, Keita K.
As reported in this alog (#89073) from Masayuki and Keita, after we turned the power in HAM1 up to 1W we found a series of vertically spread ghost beams aroubnd the main beam after the EOM and before JM3.
These could not be removed by translating, yawing or pitching the EOM position relative to the beam. It was decided in a larger meeting with EOM design personnel that we would first check if the crystal was cracked or damaged anywhere in case this is the cause.
First photo shows the EOM from above, using a green torch to illuminate the beam path. I can't see any scatter from defects or cracks in the crystal.
Second photo shows possibly a chip at the corner, but this should not affect the beam as its right at the edge.
Third and fourth show side view with illumination from the top at an angle.
In summary we did not see any 'smoking gun' to cause these ghost beams.
Very rough power estimate for the ghost beam(s) is ~O(1%)
Jennie and Jason set up another temporary iris between JM2 and JM3, centered it with 1W into HAM1 to carefully block the ghost beams without blocking the main beam, then changed the power to 100mW (for safety) and measured the power at various places. Measurement accuracy cannot be great (Jennie and Jason says the numbers were jumping around as it was difficult to hold the power meter head at a fixed position mid-air) but I would say the power in the ghost beams is ~O(1%).
| JAC out | ~105mW |
| Between JM2 and the iris (includes wrong-pol beam) | 104~105mW |
| After the iris (wrong pol as well as ghosts blocked) | 99~100mW |
| Wrong-pol beam | 1~3mW |
| Background light (no beam) | 1~2uW |
Where do they go?
After opening the temporary iris that we just put in all the way, the iris just downstream of JM3 was already blocking some of the ghost beams as well as the wrong polarization beam (JM3iris.jpg). Vertical beams don't look vertical because the iris is not a flat plane and we have a large parallax here. Anyway, it seems that we can block further if we want to from the top and the bottom.
The picture of the last iris on HAM1 shows that something is blocked on the left (+Y) side (outputiris.jpg). Looks like the iris is clipping something on the right but the camera couldn't be positioned to have a good view for both sides.
The last picture (after_last_iris.jpg) shows the beam right after the last iris on HAM1. You can see that some ghost beams are still coming through.
With this beam injected into HAM2 and misaligning MC2, we looked into IOT2L to see the MC REFL beam. We weren't able to find ghost beams there, though Jason and I felt that the beam is not super clean.
One question Jason had was whether or not the diverging beams that originate from the EOM location are supposed to keep diverging after lenses.
The beam after the second lens is actually not diverging. According to this plot, we suppose to be able to find the splitted beams in the IOT2 table.
EPO taggin'.
Randy, Ibrahim
Randy and I put the BBSS in the can today, as shown by pictures.
Following LLO's advice from their experiences in alog 79950, we were able to use the aluma lift to can the BBSS. What we did in order:
1. Strip locked-mass BBSS of all cables, check for looseness, bring alum-a-lift into position to lift BBSS from lifitng bars
2. Undo dog clamps to let lift take suspension load, ensure suspension is secured on the lift. Move BBSS out of test stand - as LLO said, very small clearance.
3. Prepare temporary platform for lift fork adjustment
4. Set BBSS on temporary platform - this part was successful but needed extra blocks to avoid interference with Y-bracks on the Lower Structure.
5. Adjust forks to be allow for canning without bottoming out, relift.
6. Put into wiped-down can and check for looseness. Rewipe, check for particulate and ensure secure fit
7. Close doors.
See pictures below.
EPO taggin'.
(Jordan V., Gerardo M.)
-Late entry
On Friday we removed and replaced the ion pump for HAM3. We replaced the copper gasket twice, the first gasket seal had a bad leak, it was hard to see the mating surfaces due to visibility issues (laser safety goggles and not enough light).
After installing a second gasket, we started pumping down the annulus system and pressure went down fast. Last pressure reading at the aux-cart was 4.63x10^-05 Torr.
BTW, we have other 4 (four) ion pumps to replace.
EPO taggin'.