Displaying reports 1-20 of 88487.Go to page 1 2 3 4 5 6 7 8 9 10 End
Reports until 01:39, Saturday 18 July 2026
LHO VE (VE)
gerardo.moreno@LIGO.ORG - posted 01:39, Saturday 18 July 2026 (91115)
Attempt at Helium Leak Checking

(Travis, Gerardo)

I chose the wrong viewport to start leak checking. 

Travis and I decided to use the XBM turbo station to leak check the new joints affected by the vent.  At the turbo station we substituted the helium leak detector in place of the nominal local scroll pump at the the exhaust of the XBM turbo, and then the Vertex and YBM turbo stations were valved-out of the main vacuum envelope.  Once the setup was established the leak detector reported a background of 1.0x10-10 Torr*l/sec.  I started spraying the first viewport, but I picked the new CHETA viewport.  Anyways, in short, I manage to saturate the leak detector, why? Because the CHETA vp is an O-ring viewport, and helium can permeate thru O-rings with ease, and I was spraying for regular CF joints, like if I was using a garden hose, in time the leak detector signal went up to 2.4x10-09 Torr*l/s, we stopped leak checking and valved in the other two turbos, and valved out the leak detector from the XBM turbo station via an O-ring valve, and restored its scroll pumping.  We'll try again Monday.

H1 SEI
arnaud.pele@LIGO.ORG - posted 21:04, Friday 17 July 2026 (91111)
Corner sensor correction on overnight

The corner isi sensor correction was turned on at 20:45 PT and will be running overnight in order to evaluate the possible improvements from the new HAM3 CPS. It had been left off to avoid noise reinjection from people working in the LVEA, but should be ok to have on during the weekend. Having the sensor correction ON for some time will allow to compare the ISI spectra with last year's, before the CPS change, in the same control state.

A quick check of the HAM2-3 (X, Y, Z) was done before / after the change to verify there is no issues (fig 1 - blue is before, red is after). The IMC stayed locked during this transition (control signal in fig 2 - blue is before, red is after).

Images attached to this report
H1 IOO (IOO)
keita.kawabe@LIGO.ORG - posted 19:00, Friday 17 July 2026 - last comment - 22:41, Friday 17 July 2026(91110)
IMC locking (Ryan, Jennie, Elenna, Keita)

Something is really wrong but we haven't figured out what exactly that is.

As of now, IMC_LOCK guardian locks IMC automatically if we wait long enough. The problem as of now is that the FSS is hit hard when H1:IMC-REFL_SERVO_COMBOOST is enabled IF the residual low frequency component of the IMC lock error signal  (H1:IMC-I_OUT_DQ) is big. In such a case FSS is unlocked and sometimes FSS autolocker goes into a loop of state 2 to state 3 to state 2. (The problem was made worse by the JAC guardian's behavior to unlock itself whenever FSS is unlocked, and that the JAC auto locker somehow kept trying to lock to the fringe at a very low PZT voltage and immediately unlocked, but these JAC problems were solved now. See alog 91105.)

However, IMC doesn't lock with nominal gains. I had to considerably reduce MC2 gain: Overall gain was reduced by a factor of 0.035 (H1:SUS-MC2_M3_ISCINF_L_GAIN=0.035), and the M3 gain was further reduced by a factor of 0.2 (H1:SUS-MC2_M3_DRIVEALIGN_L2L_GAIN=0.2). M2 and M1 gain are nominal. (Probably the overall gain should be set upstream like   H1:IMC-MCL_GAIN or H1:IMC-L_GAIN, but that's not what I did.)

Once IMC is fully locked, IMC stayed locked unless we started changing gains too much and/or injecting huge signal. Also, fully locked, I can flip the COMBOOST switch OFF and back ON quickly without killing FSS.

We measured the IMC crossovers but they were all very wrong. 

On Monday we should measure the overll OLTF on the floor to see if the fast path is still good. If it is we can focus on diagnozing the MC2 actuation, otherwise there could be a deeper problem.

Comments related to this report
keita.kawabe@LIGO.ORG - 21:39, Friday 17 July 2026 (91112)

I left IMC with the IMC_LOCK guardian in LOCKED state about 3 hours ago. IMC unlocked twice since then due to JAC unlocking but both times JAC and IMC relocked on their own.

It seems that JAC temperature keeps drifting up, causing the JAC body length to expand. PZT driver cannot keep up and eventually JAC unlocks.

Since I'm not yet sure where exactly IMC transmission is landing, I put IMC_LOCK and JAC_LOCK to DOWN and changed the PSL power to 200mW.

Images attached to this comment
keita.kawabe@LIGO.ORG - 22:41, Friday 17 July 2026 (91114)

JAC temperature started rising on 07/14 afternoon PDT, reason unknown.

JAC heater was turned on yesterday (07/16 1300-ish PDT) which increased the temperature change rate for a while, but as of now the rate seems to be back to 07/14 level.

Images attached to this comment
H1 SQZ
daniel.sigg@LIGO.ORG - posted 17:53, Friday 17 July 2026 (91106)
ZM5 calibration box

PSAMS ZM5 strain gauge calibration:

Replaced the 82.5K resistor between pins 12 and 11 with a 61.9K one. 

Readback now ranges from -0.8V to +8.5V for PZT voltages 0 and 200V, respectively.

H1 IOO (ISC)
jennifer.wright@LIGO.ORG - posted 17:32, Friday 17 July 2026 - last comment - 18:26, Friday 17 July 2026(91105)
JAC scan voltage start changed

Keita, Elenna, Ryan,

 

Keita noticed that the JAC was sometimes finding a resonance at a very low voltage offset on the PZT actuator and running out of range when it tried to lock near as it was near the bottom rail of the PZT voltage. See the photo for an example, the scan just keeps rampign from 0, finding a resonance but not lockign successfully.

They changed this from 0V to 50V to avoid this problem. This is channel H1:JAC-PZT_DRIVER_SCAN_START for reference and is set by the guardian to the correct value of 50V in the 'SCANNING' state.

Images attached to this report
Comments related to this report
jennifer.wright@LIGO.ORG - 18:12, Friday 17 July 2026 (91107)

Daniel also changed the  H1:JAC-TRANS_A_DC_NOMINAL value from 0 to 0.0042. This was to give us a normalised cureent of around 1 on the JAC-TRANS_A beckhoff screen. This means that our trigger on level of 0.5 allows us to only trigger on larger fringes and not all the higher order modes.

This value looks like it was 0 before the power outage but was non-zero in March/April when we were commissioning. I think we must have missed this when we set the scan parameters in the guardian after initial commissioning in May 2026 and if the JAC is well aligned enough this is not so much of a problem as the HO modes are very small.

Images attached to this comment
jennifer.wright@LIGO.ORG - 18:15, Friday 17 July 2026 (91108)

I also removed the checker form the PSL decorator state in the JAC guardian that checks whether the FSS is unlocked and if so sends the JAC guardian to fault. Keita/Ryan hypothesised this was causing the JAC to unlock every time the FSS did.

Once I commented this out Keita observed that this FSS unlock is happening when the 'BOOST' filter is engaged in the common mode board by the IMC guardian. I will recheck this offline.

Images attached to this comment
jennifer.wright@LIGO.ORG - 18:26, Friday 17 July 2026 (91109)

Accepted JAC sdfs, the rets should be set by the guadrian.

Images attached to this comment
H1 IOO (ISC)
khanh.vu@LIGO.ORG - posted 16:57, Friday 17 July 2026 (91102)
JAC Commissioning - ND filters not needed
Jennie Wright, Khanh Vu

Below is a summary of the work we did on the JAC IOT1 table today, July 17th.

For JAC commissioning, we had planned to install a higher-attenuation ND filter on the JAC Trigger PD and turn down the power on the JAC REFL A PD. Our concern was that the power in the Trigger PD path might be too high and cross its trigger threshold. We came in to measure the beam power with and without the ND filter.

With ND filter: 12.51 mW between the ND filter and beam splitter; 2.1 mW in front of the REFL PD.
Without ND filter: 0.39 V on TrPD; 6 mW on REFL PD.

The power on REFL PD is not too high even without the ND filter and with JAC unlocked, so we decided to check our calculations.

Using existing data from when the JAC was locked vs. unlocked (attached below), we found a visibility of 65.9/922.2 = 0.07. This is higher than my previous calculation of 0.056, but since the numbers are so small, the fluctuation is acceptable. A higher visibility also allows a larger error margin, which is preferable for ensuring the power does not get too high during a run.

The calculated power on REFL PD at 65 W locked is 13 mW, and the calculated voltage on TrPD is 0.89 V. These numbers look good even without ND filters, so we don't need to change or install them.
Images attached to this report
H1 General
anthony.sanchez@LIGO.ORG - posted 16:31, Friday 17 July 2026 (91103)
Friday Ops shift report.

TITLE: 07/17 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:
While the Earthquake slowly rolled through the site CDS took some time to do some updates and restart the Data concentrator 18:02 UTC 
19:48 UTC CDS seemed to recover.

Ryan C and I were wondering why ISC_LOCK wouldn't get to idle. He traced it through ISC_Lock log and found that the ETM X&Y ESD drivers has not recovered from the power outage. Marc went down there to rest the High voltage. But they still are not working properly and there is a very slow barely noticeable increase to the  H1:SUS-ETMX_M0_FASTIMON_F1_OUT16 channles that seems to be growing. Rahul has been contacted and he's going to look at it and he may leave it in safe if it continues to grow in amplitude.

IMC locking team has been trying to get it locked but has been running into chris-crossed-overed settings and are still activley working on locking IMC.


VAC Team have made gains in getting the vacuum pressures to continue to go down, so Pump down Continues!

Jack team is cleaning up for the weekend.

LOG:                                                                                                                                                                                                                                                                          

Start Time System Name Location Lazer_Haz Task Time End
14:38 FAC Kim & co LVEA y Technical Cleaning and resuply 15:09
15:57 FAC Kim LVEA Y Technical Cleaning & ReSupply 17:24
16:12 PSL Jason Control RM N Tweeking Ref Cav and PMC 16:53
16:32 JAC Jennie & Khanh Optics lab/ LVEA Y Looking for power meters. 16:56
17:02 SUS Ryan C Control Rm N Transfer functions on ZMs 17:20
17:04 pcal Tony PCAL lab yes Recovering PCAL lab from Power outage & Setting up new measurement. 17:54
17:20 SUS Rahul, RyanS LVEA Y HAM7 work, ZM alignment, Rahul Out first 18:27
17:21 SEI Jennie LVEA Y Unshutter SPI 17:24
17:29 FAC Mitch LVEA Y Turn OFF Bier Garten cleanroom 17:45
17:47 VAC Gerardo LVEA Y Setup AUX cart by GV2 18:47
18:02 VAC Travis, Gerardo LVEA y Setting up Leak detector 22:53
18:38 CDS Jonathan MSR N DAQ  & Data concentrator restarts 20:09
19:07 Jac Jennie LVEA yes Workign on Jac? 19:20
19:19 JAC Jennie, Khanh LVEA Y JAC table power measurements 20:28
20:54 TCS Madi Optics lab N Workin on lens checks with Eye safe laser. 23:26
21:18 EE Marc EX & EY N pressing the ESD HIgh Voltage rest button 21:58
21:45 Safety Richard LVEA y Checking on the Vacuum Crew status 22:19
22:08 SUS Daniel LVEA y Straining the ZMs 22:14
22:57 CDS Jonathan Remote N Restarting the DAQ stat service 23:22
23:30 JAC Jennie, Khanh LVEA y Cleaning up. 00:00

 

H1 CDS
jonathan.hanks@LIGO.ORG - posted 13:59, Friday 17 July 2026 - last comment - 17:05, Friday 17 July 2026(91101)
WP 13402 cleanup and daqd restarts

As part of WP 13402 we did some daqd restarts today.  These were to pull in changes to the EDC to reflect the reconfiguration of the DAQD system and the additional channels generated by the safety system update.

In addition on review of the system wiring, we switched the location of two fibers on h1daqdc1 to keep it consistent with the fiber layout on h1daqdc0.   The fibers where the link to the front end data stream, and the live data stream to the NDS2 systems.

This was the first time that we had done a channel list change since updating the daqd config.  This found an error in our puppet configuration.  Normally when the data concentrator machine starts up it grabs the channel list from the main copy, and stores a copy of the channel list that all the other daqd in its leg refer to.  This keeps a stable copy of the channel list that only updates on restarts.  During the puppet reconfiguration, this addition to the startup sequence got lost and was not applied on h1daqdc1.  It didn't show itself until we did the restarts with a new channel list, at this point the frame writers where disagreeing on the channel list.  This has been fixed in our puppet config now.

After some minor cleanups, a fiber re-arrangement, and several restarts and debugging the daqd system is running, the edc is connected to all its channels.

Comments related to this report
jonathan.hanks@LIGO.ORG - 17:05, Friday 17 July 2026 (91104)

With these changes done, I also did some updates to the daqstat ioc and medm screens.  Now it properly reports the daqd system is in good health which greens up the CDS overview a bit.

H1 SQZ (SQZ, SUS)
rahul.kumar@LIGO.ORG - posted 11:44, Friday 17 July 2026 (91097)
HAM7 alignment work - ZM4 (Yaw) mechanically offloaded and the beam looks great on SQZT7 table.

Ryan Short, Rahul Kumar

We mechanically offloaded SUS ZM4 (PSAMS) in Yaw dof. (rotating the suspension cage clockwise on the table) to relive it's alignment slider values which were taking up too much of DAC output (20k counts approx.).

At first we marked the beam position on the periscope and the two irises on SQZT7 table. We then set the Yaw sliders to zero on ZM4. The beam moved a little but was still pointing on the periscope and was not too bad on the two irises. Then, I rotated ZM4 (clockwise) until the beam returned to its nominal position (Ryan kept an eye on the beam position on the iris). The beam looked great on the periscope as well. We then checked how the beam looked on ZM4, ZM5 and the beam divertor in HAM7 chamber and they looked well centered on the optic. 

I re-attached all five dog clamps on ZM4.

Ryan is still fine tuning the alignment using sliders - however, the DAC output on both ZM4 and ZM5 are now around 10k and 12k respectively.

H1 ISC (IOO, ISC)
keita.kawabe@LIGO.ORG - posted 11:18, Friday 17 July 2026 - last comment - 13:48, Friday 17 July 2026(91096)
IMC-MC2_TRANS whitening/awhitening mismatch

IMC_LOCK guardian thinks that the IMC is never locked even when it momentarily locks because IMC-MC2_TRANS_NSUM_OUTPUT is smaller than threshold.

I noticed that the MC2_TRANS_NSUM_OUT_DQ stayed negative all the time when the IMC was flashing (mismatched_whitening2.png).

I checked the whitening of the segments and somehow stage 1 whitening was on but the anti-whitening was off (mismatched_whitening.png).

I pressed "OFF" and then "ON" for stage 1 on the MEDM screen to make the whitening/awhitening in sync again. I made the stage 1 whitening OFF after this.

I haven't checked when the problem started but most likely at the time of power outage.

I'll ask the operator to check if there are other mismatches.

Images attached to this report
Comments related to this report
anthony.sanchez@LIGO.ORG - 13:48, Friday 17 July 2026 (91100)

Kieta's great attention to detail noticed a whitening filter bank that did not have a matching anti-whitening filter.

So Ryan C. and my self populated a Spreadsheet that has all the LSC Whitening Sensors on it with their filterbank's whitening status.
It shows which Whitening filters are on, which Anti-Whitening filters are on. And if they don't match for what ever reason they turn red.

H1 SQZ (SQZ, SUS)
rahul.kumar@LIGO.ORG - posted 17:06, Thursday 16 July 2026 - last comment - 10:21, Friday 17 July 2026(91078)
HAM7 beam alignment work.

Sheila, Camilla, Ryan S, Cory (Fellow), Rahul

Given below is the summary of beam alignment work we performed in HAM7 today.

After locking the SQZ beam and the OPO we first checked the alignment on the OPO - it looked good and there was no clipping anywhere. Then we checked the beam on ZM4 and ZM5. Camilla measured the incoming beam on ZM4 to be 5.5inches approximately and it looked well centered on the iris in front of it.

On ZM5 the beam was very high on the optic (we had to remove the face baffle to be able to see the beam on the PSAMS mirror). At first we tried using  ZM4 sliders to center the beam on ZM5, but ran out of range. Hence, we mechanically adjusted ZM4 in pitch (using the pitch adjuster) to bring the beam down on ZM5 and center it (Camilla took pictures for reference). 

The beam from ZM5 to the beam divertor was off in both pitch (beam too low) and yaw (too wide as well, almost missing). We first adjusted ZM5 in yaw (mechanically) to center it on the beam divertor - we also had to push it slightly (less than 3mm) side ways for this purpose. With Yaw looking good on the beam divertor, we tried using sliders for Pitch but quickly ran out of range. I then used the mechanical pitch adjuster, but even that was not enough (ran out of range here too). Hence, I added 50grams of weight to the rear side of ZM5 intermediate mass to pitch it up (by 0.5inch) on the beam divertor. This worked and the beam looked good both in pitch and yaw on the beam divertor. 

Finally Ryan S checked the beam on the periscope and the two irises on SQZT7 table. It was off in Yaw - so I applied a negative yaw (clockwise rotation) on ZM5 mechanically (again the sliders were not enough for this big move) using dog clamps and round end screws (for better yaw control). While I rotated ZM5 in Yaw, Ryan S held an IR card on the periscope (SQZT7 table) and Camilla kept an eye on the beam, telling us when to stop. Once we were satisfied in both pitch/yaw on the periscope, Ryan S looked at the two iris in SQZT7, and he was happy with it as well.

I dogged down ZM5 and also re-attached the face baffle before closing the curtains on HAM7 chamber. Camilla started using sliders to fine tune the alignment.

Tomorrow morning I will take health checks on both ZM4 and ZM5 suspensions. 

Comments related to this report
ryan.crouch@LIGO.ORG - 10:21, Friday 17 July 2026 (91095)

I ran some quick TFs on ZM4 and ZM5 (3 avgs, 0.02 bw) this morning, and they are both looking good.

H1 AOS (IOO, ISC)
keita.kawabe@LIGO.ORG - posted 15:14, Thursday 16 July 2026 - last comment - 10:03, Friday 17 July 2026(91079)
Relocking JAC (Jennie, Keita)

Alignment into JAC was not great. Since JAC wasn't thermalized yet (heater was turned on merely 30minutes or so before we started aligning) and the fringes weren't staying put relative to the PZT voltage, I injected more than 250Vpp (with an appropriate offset) into JAC PZT to make sure that more than FSR is scanned and manually aligned JM1 and PSL PZT until 10/01 mode became less than 10% of 00 mode. Didn't bother to refine further. Attached shows the JM1 and PSL PZT alignment offsets.

I zero-ed the dark offset of JAC_REFL_A_RF43.

We had to turn on FM10 ("W_in_HAM2" which is not calibrated in reality) which was disabled at some point.

JAC guardian was able to lock JAC after the above.

We are able to see flashing in MC TRANS camera now, seems like it's mainly off in yaw but we can see 00 mode once in a while. Nothing in MC REFL camera, we'll work on IOT2L next.

Images attached to this report
Comments related to this report
keita.kawabe@LIGO.ORG - 18:01, Thursday 16 July 2026 (91086)

IOT2L alignment 1st round (Jennie, Elenna, Keita)

Without doing any fine alignment, IMC REFL diode was centered using the steering mirror after the bottom periscope mirror. Shifted one of the beam dumps a bit as I felt like one of the beam dumps for blocking the wrong polarization beams (or maybe AR reflections) was too close to the main beam.

IMC WFS sensors were centered using pico mirrors.

IMC REFL camera was centered using the last steering mirror.

After this, we found that JM3 needed to be rotated in PIT (which means YAW in the IMC coordinate) to roughly align the JAC output into IMC.

  before I started after roughly aligned
H1:SUS-JM3_M1_OPTICALIGN_P_OFFSET -54 85
H1:SUS-JM3_M1_OPTICALIGN_Y_OFFSET 297 297

Attached video shows how the MC REFL beam goes dark when IMC is locked for a few seconds. As you can see the alignment is already pretty reasonable. This is just manual lock via fast path, no boost no feedback to MC2 no nothing. IMC guardian doesn't want to lock IMC (yet).

I disabled all ASC output to mirrors and set the H1:IMC-WFS_GAIN to zero so LOCK state should not confuse you about the alignment even if ASC is "turned on".

Non-image files attached to this comment
ryan.short@LIGO.ORG - 18:40, Thursday 16 July 2026 (91089)

Jennie and I continued trying to lock the IMC for a bit this evening after Keita's attempts, but weren't successful.

We did discover, however, that an MC2 length excitation was left running, which may have confused some of the locking attempts when using the Guardian. We killed this excitation and tried the Guardian again, but still no luck. Jennie also discovered when browsing SDFs that the IMC-L gain had been stepped from 1.0 to 0.1 then 0.01 at around 00:30 UTC. We assumed this was part of Keita's locking attempts, but since it was not mentioned as necessary in any logs and it had been 1.0 for several years, we put the gain back to 1.0 and tried the Guardian once more. Sadly, this didn't seem to help either. We're leaving the IMC-L gain here and if someone else deems it should be different, they're welcome to change it back. 

keita.kawabe@LIGO.ORG - 10:03, Friday 17 July 2026 (91094)

MCL gain was me (sorry).

Excitation was me, too (sorry again) but it was 1 ct pk-pk and has zero effect on locking.

LHO VE (VE)
travis.sadecki@LIGO.ORG - posted 13:03, Thursday 09 July 2026 - last comment - 17:32, Friday 17 July 2026(90967)
HAM7 A1F1 and A2F1 viewports removed and blanked off

Per FRS 38164, the unused viewport located at A1F1 and A2F1 on HAM7 have been removed and blanked off.  These viewports are being moved to HAM3, so serial number, etc. will be recorded in a separate aLog.

Images attached to this report
Comments related to this report
jordan.vanosky@LIGO.ORG - 08:45, Friday 10 July 2026 (90983)VE

The HAM3 A1F3 viewport was a coated ZV-800 which had many small scratches on the vacuum side of the window, we replaced this with the HAM7 Uncoated ZV-800 SN R136. The A1F4 viewport was a D1100999 High Quality viewport (O-ring sealed), it was determined that this port no longer needs the high quality viewport and was then swapped with the other removed viewport from HAM7 (ZV-800 Uncoated R134).

Per Betsy, both of these ports are only used for views inside the chamber, so Uncoated viewports could be used to replace the two coated viewports which were removed.

The viewports removed from HAM3 will be inspected on the bench and if they pass inspection criteria they will be put into spares inventory.

Images attached to this comment
melina.fuentes-garcia@LIGO.ORG - 17:32, Friday 17 July 2026 (91098)

After confirming with Jordan, the comment above has a small typo: The viewport that came off of HAM7 port A2F1 is recorded in LHO's inventory lists (LIGO-T1200220 and LIGO-E2400096) as SN R146 (not R136 as listed above).

As a visual indicator of these swaps: 

HAM7 A2F1 SN R146 → (removed and moved to) → HAM3 A1F3

HAM7 A1F1 SN R134 → (removed and moved to) → HAM3 A1F4

Displaying reports 1-20 of 88487.Go to page 1 2 3 4 5 6 7 8 9 10 End