Displaying reports 1-20 of 88951.Go to page 1 2 3 4 5 6 7 8 9 10 End
Reports until 19:51, Wednesday 19 August 2026
LHO General
thomas.shaffer@LIGO.ORG - posted 19:51, Wednesday 19 August 2026 (91604)
Ops Day Shift End

TITLE: 08/19 Day Shift: 1430-2000 UTC (0730-1300 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Oli
SHIFT SUMMARY: GV6 & 8 were opened this morning, so we now have a full IFO to commission. Commissioners have been hard at work aligning to the arms. 
LOG:                                                                                                                                                                                         

Start Time System Name Location Lazer_Haz Task Time End
16:32 SEI Jim, Huyen LVEA - H2 y CRS wrapping 17:56
16:32 DAS Reinhardt LVEA y Fiber checks 19:55
16:39 FAC Randy LVEA y Craning scissor lift and 3IFO container 18:00
17:09 VAC Gerardo LVEA y Isolating turbos then opening GV6 & 8 18:05
17:16 JAC Jennie LVEA Y JAC table meas 18:03
17:16 DAS Jenne LVEA y Checking in with Reinhardt 17:30
17:29 PEM Robert, Miranda LVEA y Check on acc. name 17:36
18:03 SQZ Camilla, Ryan S LVEA y HAM7 area cleanup 19:19
18:19 ISC Jennie Opt Lab n Plug in power meter 18:45
19:08 SAF Jackie Ends n Taking pictures of first aid kits 20:08
19:20 ISC Camilla Opt Lab n Clean up 19:29
H1 ISC (SUS)
elenna.capote@LIGO.ORG - posted 19:10, Wednesday 19 August 2026 (91602)
Successful commission of BS M3 feedback for MICH

Louis and I immediately started where we left off yesterday with BS M3 commissioning. Louis copied over the LLO filter design that sets up the BS feedback with a 7 Hz crossover between M2 and M3, 82200 (thanks LLO for doing the heavy lifting here!).

I copied these filters into my matlab model so we could confirm we understand what it is doing. This plot shows the modeled feedback with the locking and drivealign filters applied. The LLO design is applied to M2 and M3, such that the crossover is roughly 7 Hz as expected. I applied our current M1 offloading scheme, and the M1/M2 crossover is still 30 mHz.

This looks good to us, so we proceeded to copy over the filters to the BS sus banks. I first locked MICH dark using the old feedback design without the lowpass filters so we had much more phase. This provides a reference for us to make sure we do the switchover correctly.

Louis and I engaged the correct filters in ISCINF M3 L, M3 lock L, M3 drivealign L2L and M2 lock L. Here is a screenshot of the old M2 filter design, and here is a screenshot of the settings we used to test the new feedback. I want to note that one difference is I found that we need a gain of -1 overall in BS M3 drivealign to get the phase correct.

I did touch up the MICH alignment before locking, since the arm team is working on aligning the arms now that gate valves are open (spoiler alert).

We successfully locked MICH dark, no issues! I measured the MICH olg again, and saw that we were almost exactly where we wanted to be in the gain, and the phase is a little different but not drastically so.

Masayuki noted in a previous alog that the MICH gain is a bit low, it would be better to have a 10 Hz UGF. Therefore, I bumped up the gain by a factor of 3 and remeasured. Looks good! This plot compares all three MICH dark olgs.

Louis has updated the ALIGN_IFO guardian with these new settings and is working through ISC_DRMI. In addition to the filters in the BS sus, we are updated the MICH dark and MICH bright gains to be 3x higher (so plus/minus 7200 instead of 2400).

As a note, ALIGN IFO does not use M1 feedback, we expect to test this when we lock PRMI/DRMI. However, I don't predict any issues, as the crossover should still be the same.

I have accepted new settings in the SDF as well, screenshot.

Below are the foton strings that we copied over:

BS_M2_LOCK_L

FM1: zpk([-4.398229715026552+i*5.654866777052986;-4.398229715026552-i*5.654866777052986], [-344.8589087698574+i*562.4185982606715;-344.8589087698574-i*562.4185982606715; -2513.274122871833],21314144.89497595)

FM2: zpk([0+i*754.0107241782374;0-i*754.0107241782374], [-114.2660735869546+i*205.9572881820654;-114.2660735869546-i*205.9572881820654], 0.09757621338967941)

FM4: zpk([],[-50.26548245743591],50.2654824574367)

BS_M3_DRIVEALIGN

FM1: zpk([],[],298.5382618917961)

FM2: zpk([0],[-50.26548245743591],1.003192)

FM3: zpk([0+i*1.232546515546514;0-i*1.232546515546514;0+i*2.235392999096904;0-i*2.235392999096904], [-0.1284339970099986+i*2.497529352797497;-0.1284339970099986-i*2.497529352797497; -1.722920509773179+i*2.801700651589354;-1.722920509773179-i*2.801700651589354], 0.9928357135551715)

FM10: zpk([0+i*2021.046153045786;0-i*2021.046153045786;0+i*4405.443648178848;0-i*4405.443648178848], [-457.9243327239894+i*601.6182012226579;-457.9243327239894-i*601.6182012226579; -132.3004333168722-i*1248.734723957288;-132.300433316874+i*1248.734723957288], 0.01013394010636035)

Images attached to this report
H1 AOS
khanh.vu@LIGO.ORG - posted 17:48, Wednesday 19 August 2026 (91598)
New WFS Balancing Measurement

As promised, this morning I took a new measurement of the JAC reflected beam on wavefront sensors A and B. This time, we unlocked the JAC, which provided a cleaner beam for centering in both pitch and yaw. The results were much better, with the relative differences between segments reduced to below about 10%.

As a sanity check, we compared the measured and calculated G1/G4 ratios for WFS A and WFS B, as shown in the attached table. For WFS A, the discrepancy is about 10%, while for WFS B, it is only about 2%. We think the remaining error may come from beam clipping when we attempted to recenter the beam between the two halves, the approximately 1 mm gap between the quadrants, or pitch-yaw cross-coupling.

Overall, this measurement gives us an estimate of the uncertainty associated with this technique for measuring the relative segment gains.

Images attached to this report
H1 ISC
elenna.capote@LIGO.ORG - posted 16:59, Wednesday 19 August 2026 - last comment - 19:57, Wednesday 19 August 2026(91593)
PRMI locking, attempt to commission BS M3

Long day, short alog

We continued to try to lock PRMI today. After consulting with Sheila, we moved IMs1-3 back to the alignment they had during the arm peek last week. Ryan S has noted the osem values for each alignment, so we can switch back and forth between these two configurations. Then, Louis and I reverted IM4, PR2, PRM, SRM, SR2, BS to their alignments during a DRMI lock last week. I also moved SR3 to its current alignment (TCS team had moved it back to old O4 alignment for HWS work).

This alignment was very bad for flashes, so I iterated between initial alignment work on PRX and MICH, and running a PRMI lock. We found that it was very difficult to lock PRMI, both because the alignment was poor and the beamsplitter was moving a lot. Once we turned back on BS oplev damping, PRMI locking was more frequent due to less BS motion, allowing us to better touch up the alignment. However, there was then a large 6 Hz oscillation. After checking many things, it turns out the oplev damping is causing this oscillation, both PRCL and MICH are stable. So, we need oplev damping to lock but we can't keep it on or we will unlock.

After talking with Sheila again, I moved to try commissioning the BS M3 feedback as a way to help this problem. Louis and I tried measuring the beamsplitter plant with the offloaded feedback to M2 and M1 and then M3 and M1. We found that we needed about a gain of -300 on M3 to replicate the M2 plant. However, we could not lock MICH dark with this feedback.

We tried many different things after this which I won't detail, but Keita and I performed a different type of measurement that confirmed the work Louis and I did earlier was correct. When we locked again, we saw that the issue is that the DAC rails. Looking at the master outs on M3, the saturation occurs below 10 Hz. I see that we should replicate the LLO feedback that is distributed between M2 and M3 with a crossover of 7 Hz. See 82200. I will pick this up tomorrow.

Editing to add spectrum of BS M3 master out with length feedback applied and the appropriate gains. I put a horizontal line roughly at 134e6 DAC counts, which is where we expect the saturation to occur on our 28 bit DACs. A crossover of 7 Hz as LLO has would work well. Louis is copying their filters over now.

Images attached to this report
Comments related to this report
ryan.short@LIGO.ORG - 19:57, Wednesday 19 August 2026 (91605)ISC

The two configurations Elenna notes for the IM alignments are as follows (all values in terms of suspension OSEMs):

  Pre-EQ (8/10) Arm peek (8/11)
IM1 P 2865 P 2879
Y -1027 Y -1025
IM2 P 161 P 43
Y 421 Y 412
IM3 P 269 P 259
Y -1216 Y -1215

As of 1pm local time today (August 19th), we are in the pre-EQ (8/10) IM configuration.

LHO General
thomas.shaffer@LIGO.ORG - posted 14:33, Wednesday 19 August 2026 - last comment - 21:17, Wednesday 19 August 2026(91595)
Ops Day Shift Start

TITLE: 08/19 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: CALM
    Wind: 4mph Gusts, 1mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.07 μm/s 
QUICK SUMMARY: Dust alarms in the PSL overnight, but they quickly dissapated. There was a verbal alarm at 0828UTC "Check corner station HEPI pumps", I don't initially see any issues but I'll continue to investigate.

Plan today is continued corner station commissioning unless we get the arms opened.

Comments related to this report
thomas.shaffer@LIGO.ORG - 14:55, Wednesday 19 August 2026 (91596)SEI

Sure enough there was a brief pressure dip in the CS HEPI pump pressures that it immediately recovered from. The 4 pumps and the supply and return all see it.

Images attached to this comment
thomas.shaffer@LIGO.ORG - 16:55, Wednesday 19 August 2026 (91599)

Looking into this a bit further, pump 4 sees the largest pressure change. Local IPS sensors on HAM3 see this change, but Jim said that their locationmon channels did not see it.

Images attached to this comment
patrick.thomas@LIGO.ORG - 21:17, Wednesday 19 August 2026 (91606)
Looking at the plots, it appears that the drive signal sent from the PLC to the VFD increases in response to the drop in pressure, so would indicate a response rather than a cause.
LHO General
ibrahim.abouelfettouh@LIGO.ORG - posted 02:15, Wednesday 19 August 2026 (91594)
OPS Eve Shift Summary

TITLE: 08/19 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

IFO is in IDLE with IMC Locked and Power at 2W

Evening was spent trying to comisson BBSS M3 stage as a way to aid with alignment. Keita, Louis and Elenna have some next steps to try tomorow. See alog 91593.

After they were finished and per Jennie's instructions I changed the JAC Heater POWER_SET from 1.465 to 3. Then, I informed Huyen that Seismic overnight tests can begin.

LOG:

Start Time System Name Location Lazer_Haz Task Time End
14:54 FAC Kim EX - Technical cleaning 16:21
15:01 FAC Eric Outbldgs - AHU checks 16:47
15:52 PEM Robert LVEA - Looking at fiber locations 17:33
16:01 VAC Travis LVEA - Moving pump from HAM1 to HAM6 16:30
16:32 FAC Kim LVEA - Technical cleaning 17:36
16:34 PSL Jason PSL Y Parts search 16:50
16:41 SEI Jim CER - HAM3 ISI measurement 18:24
16:48 FAC Chris LVEA - Safety checks 17:37
16:53 TCS TJ, Camilla LVEA Y Checking HWS and CO2 tables 19:46
17:33 PEM Robert, Reinhardt MER/LVEA - Running DAS fibers (Robert out at 23:52 UTC) 00:29
17:56 FAC Kim FCES - Technical cleaning 18:55
18:08 TCS Jennie LVEA Y Looking for RF source 18:19
18:11 VAC Travis, Gerardo LVEA - Valve in HAM6 turbopump 18:24
18:26 TCS Fil LVEA - Troubleshooting CO2 laser 19:46
18:47 AOS Betsy LVEA - Checks in W-bay 19:08
19:34 FAC Randy LVEA - Pulling 3IFO ISI container lid 22:30
19:48 SUS Jason OptLab - Checking oplev lasers 21:39
20:08 VAC Gerardo LVEA - Starting leak detector on BSC8 23:31
20:14 AOS Betsy LVEA - W-bay cleanroom move 21:25
20:19 VAC Travis LVEA - Leak checking and cleanroom move 23:25
20:29 AOS TJ LVEA - W-bay cleanroom move 21:09
20:56 SEI Shoshana, Huyen, Jim LVEA - H2 PSL - CRS cleanup 22:37
21:25 TCS Camilla, TJ LVEA Y CO2Y troubleshooting 22:48
22:11 EE Jackie MER - Replacing BHD chassis 23:12
23:29 TCS Camilla OptLab - Tidying up 23:54
00:10 PEM Robert EX Y Finding glasses 00:23
01:54 VAC Gerardo LVEA Y HAM6 Turbopump valve 02:08
H1 DAQ
jonathan.hanks@LIGO.ORG - posted 23:38, Tuesday 18 August 2026 (91591)
WP 13504 investigating higher rate of transport issues

Since enabling irqbalance on dc0 we seen less CRC errors (only around restart times for the last few days).

Today we enabled irqbalance on dc1.  Unlick on dc0 there was a small (but visible) dip in the average cpu use.

We will continue to watch this.

LHO General
ryan.short@LIGO.ORG - posted 23:36, Tuesday 18 August 2026 (91588)
Ops Day Shift Summary

TITLE: 08/18 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Were were able to get PRMI locked again today for a bit after more alignment work, and then some commissioning of the BBSS was done after that. The HWS and CO2 systems were worked on and some 3IFO checks were done as well. Dust alarms have been going off most of today in the optics lab. The LVEA remains Laser HAZARD.
LOG:

Start Time System Name Location Lazer_Haz Task Time End
14:54 FAC Kim EX - Technical cleaning 16:21
15:01 FAC Eric Outbldgs - AHU checks 16:47
15:52 PEM Robert LVEA - Looking at fiber locations 17:33
16:01 VAC Travis LVEA - Moving pump from HAM1 to HAM6 16:30
16:32 FAC Kim LVEA - Technical cleaning 17:36
16:34 PSL Jason PSL Y Parts search 16:50
16:41 SEI Jim CER - HAM3 ISI measurement 18:24
16:48 FAC Chris LVEA - Safety checks 17:37
16:53 TCS TJ, Camilla LVEA Y Checking HWS and CO2 tables 19:46
17:33 PEM Robert, Reinhardt MER/LVEA - Running DAS fibers 00:17
17:56 FAC Kim FCES - Technical cleaning 18:55
18:08 TCS Jennie LVEA Y Looking for RF source 18:19
18:11 VAC Travis, Gerardo LVEA - Valve in HAM6 turbopump 18:24
18:26 TCS Fil LVEA - Troubleshooting CO2 laser 19:46
18:47 AOS Betsy LVEA - Checks in W-bay 19:08
19:34 FAC Randy LVEA - Pulling 3IFO ISI container lid 22:30
19:48 SUS Jason OptLab - Checking oplev lasers 21:39
20:08 VAC Gerardo LVEA - Starting leak detector on BSC8 00:08
20:14 AOS Betsy LVEA - W-bay cleanroom move 21:25
20:19 VAC Travis LVEA - Leak checking and cleanroom move 00:17
20:29 AOS TJ LVEA - W-bay cleanroom move 21:09
20:56 SEI Shoshana, Huyen, Jim LVEA - H2 PSL - CRS cleanup 22:37
21:25 TCS Camilla, TJ LVEA Y CO2Y troubleshooting 22:48
22:11 EE Jackie MER - Replacing BHD chassis 23:12
H1 IOO
khanh.vu@LIGO.ORG - posted 23:20, Tuesday 18 August 2026 (91589)
WFS Balancing

Jennie Wright, Masayuki Nakano, Khanh Vu

Masayuki’s Math

We previously made an attempt to balance the JAC’s reflected beam on the WFS quadrants. However, Masayuki realized that this might not be a fair measurement because the voltage is defined as Voltage = Gain x Power, and the gain can be different for each segment.

To obtain a quantity that can be compared between segments, we instead excite the beam. For example, we can move the beam to the upper half of the WFS (Segments 1 and 2) so that no light lands on the lower half (Segments 3 and 4). If we then drive the beam in yaw with a sine wave, the total power on Segments 1 and 2 must be conserved. Therefore, any change in power on one segment results in a corresponding negative change on the other segment.

The powers on Segments 1 and 2 can then be written as:

P1 = P1_DC + ΔP sin(wt)

P2 = P2_DC - ΔP sin(wt)

Since Voltage = Gain x Power,

V1 = G1 x (P1_DC + ΔP sin(wt))

V2 = G2 x (P2_DC - ΔP sin(wt))

At the excitation frequency, the amplitudes of the power changes on the two segments are equal and opposite. Therefore, taking the ratio of the measured AC amplitudes gives the gain ratio G1/G2.

Applying the same procedure, we can measure G1/G2, G2/G3, G3/G4, and G1/G4. However, we can also infer G1/G4 from the first three ratios:

G1/G4 = (G1/G2) x (G2/G3) x (G3/G4)

Comparing this inferred value with the directly measured G1/G4 gives us a consistency check.

Measurement Procedure

We performed this measurement by injecting an excitation into the JM1 suspension system. Before doing so, we opened the ASC loops and paused the JAC Guardian. We used the picomotors to move the beam onto different halves of the wavefront sensors.

For precision, we monitored the DC signals from the individual segments. Using the same example, when positioning the beam on the upper half, we moved it until there was essentially no signal on Segments 3 and 4. We then balanced the beam in yaw so that the DC signals on Segments 1 and 2 were approximately equal. An example dtt for this step is attached below.

The excitation was a sine wave at 11 Hz with an amplitude of 12. For the upper and lower halves, we injected in yaw. For the left and right halves, we used pitch excitation. The power spectrum plot is also attached below.

Results

We measured the segment responses at 11 Hz and divided the corresponding amplitudes to obtain the gain ratios. The results are shown below.

For WFS A, the directly measured G1/G4 does not agree well with the value inferred from the other three ratios. For WFS B, the directly measured and inferred G1/G4 values agree considerably better.

However, the calculated results themselves do not seem physically reasonable, since they imply that the gains of different segments can differ by as much as a factor of 10.

Next Step

We suspect that this issue comes from performing the measurement while the JAC was locked. In this condition, the reflected beam contains significant higher-order-mode content, making it difficult to position and balance the beam cleanly on the WFS quadrants.

We will therefore repeat the measurement tomorrow with the JAC unlocked.

Images attached to this report
H1 IOO (OpsInfo)
jennifer.wright@LIGO.ORG - posted 23:01, Tuesday 18 August 2026 - last comment - 18:41, Wednesday 19 August 2026(91587)
Increased JAC heater gain

JAC Heater ran out of range this afternoon and the JAC unlocked. We started this lock stretch (first x cursor) already at a pretty high PZT offset so I might add a upper limit to how high a voltage we should lock at.

I have increased the gain magnitude in the heater control servo from -0.1 to -0.15 to try and stop this happening again before this evening when we will increase the power set value from 1.5 W to 3W to give us more headroom above ambient temperature for the servo.

Images attached to this report
Comments related to this report
jennifer.wright@LIGO.ORG - 16:35, Wednesday 19 August 2026 (91597)

Here is a plot including the control signal. With the lockloss at the first cursor and the gain change at the second.

The JAC locked again at a much lower voltage and so stayed locked until the planned increase in the set power to 3W last night caused some locklosses.

The system looks underdamped from this step response so I will test some changes to the controller over the weekend.

Images attached to this comment
jennifer.wright@LIGO.ORG - 18:41, Wednesday 19 August 2026 (91603)

I aaded an upper limit to the SCANNING state in the JAC_LOCK guardian it will only scan up to 300V instead of 330V, this should prevent the cavity locking near the upper limit of the PZT.

Loaded and committed the guardian.

H1 TCS
camilla.compton@LIGO.ORG - posted 12:53, Tuesday 18 August 2026 - last comment - 23:21, Tuesday 18 August 2026(91585)
CO2X Turned on and alignment to irises checked, Issues with CO2Y

TJ, Fil, Camilla

We turned on CO2X laser without issues. TJ had to turn on Outputs of power supplies on the mezzanine. We searched for home of the rotation stage and checked that the beam was aligned to both irises before the periscope. Leaving laser on at minimum power. Guardian did successfully lock laser. 

For CO2Y, we were unable to turn it on. We checked SMA connections on laser head, BNC and TNC connections between RF driver and laser and tried turning on in PWM mode with the PWM driver. Fil then swapped chassis D1700745 to a spare. This did not help. TJ then swapped the RF cables t the TCS-X rack for X and Y. X laser stayed working, Y laser still not working. Fil checked the AA chassis. Fil and TJ looked at swapping the power supplies at the mezzanine but this was complicated and the power supply appeared to be behaving normally. 

 

 

Comments related to this report
camilla.compton@LIGO.ORG - 23:21, Tuesday 18 August 2026 (91590)

This afternoon we swapped the chassis back. We then swapped the small square-wave RF box to the spare. And then swapped the RF driver briefly to the spare, this is not matched and we did attach cooling lines but had on for ~30seconds. Neither of these things helped so we swapped back to originals. We then noticed that the rocker switch was off on the D1300649 chassis inside the CO2Y enclosure. Turned this on and everything was fine.

CO2 Y laser turned on fine. We searched for home of the rotation stage with downstream beam dump and checked that the beam was aligned to the upstream iris before the periscope (we bumped the downstream iris while changing cooling lines). Leaving laser on at minimum power. Guardian did successfully lock laser. 

H1 TCS
camilla.compton@LIGO.ORG - posted 21:31, Monday 17 August 2026 - last comment - 12:19, Tuesday 18 August 2026(91567)
Ring heater test on ITMX and ITMY this evening. 2W/segment 4 hours.

TJ, Camilla

I put SR3 into it's O4 alignment (P 458, Y -135) changed from (P 524, Y -135), checked no saturating pixels (ITMX stayed at 1Hz frame rate, ITMY increased to 5Hz), took new HWS references and started the HWS code.

We are running a ring heater test with 2W/segment for 4 hours this evening. Using scripts below on tmux sessions:

Ring heaters should be back to nominal by ~1am. Purpose of this is to check HWS alignment before we align the CO2s (using HWS). 

Comments related to this report
camilla.compton@LIGO.ORG - 09:33, Tuesday 18 August 2026 (91580)

TJ, Camilla ITMY HWS signal looks great. ITMX HWS signal looks noisy, the power on the CCD camera is much smaller than expected, expect this needs realigning after the BS is different. 

Images attached to this comment
camilla.compton@LIGO.ORG - 12:19, Tuesday 18 August 2026 (91586)
We took the plate of HWS ITMX. With the O4 SR3 alignment, the IX HWS will need realigning, photo attached.
With the new SR3 alignment, we get the HWS beam back but we are clipped, photo, so would probably need to realign either way. This makes sense that this combination of SR3 and BS works together to give a return HWS beam. 
Wil not realign until SR3 location is decided, it is easiest for us to realign using ALS.  
 
With new SR3 alignment, ITMY HWS beam power changed ~0.1%. 
Images attached to this comment
LHO VE (VE)
gerardo.moreno@LIGO.ORG - posted 18:01, Friday 14 August 2026 - last comment - 01:45, Wednesday 19 August 2026(91555)
BSC8 PT-180 Gauge Removed and Replaced

(Travis, Gerardo)
We removed the old gauge a BCG-450 and installed a new one a BPG-552.  Since the gauge at this location does not play role with relays and such, the old pigtail did just fine, provided the power to the new gauge.  The new gauge is powered on and connected to the same EtherCAT cable as the one that that we removed.  Dead volume of this assembly is getting pumped down with a small can turbo pump and an aux-cart, and a very long flex hose, and probably will continue to pump over the weekend.
No issues were encountered while replacing the gauge.

Images attached to this report
Comments related to this report
gerardo.moreno@LIGO.ORG - 16:43, Monday 17 August 2026 (91571)VE

(Travis, Gerardo)
Aux-cart and all other accessories have been removed from this gauge.
We need to leak check the conflat on this new gauge.

gerardo.moreno@LIGO.ORG - 01:45, Wednesday 19 August 2026 (91592)VE

(Travis, Gerardo)
Today we leak checked the 2 3/4" CF joint for the new gauge at PT-180.  The leak detector did not detect a leak above the background, we connected the leak detector at the XBM main turbo pump and we sprayed the joint with copious amounts of helium.  Helium background of 6.0X10-10 Torr*l/sec.

Images attached to this comment
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