Sheila, Betsy, Camilla
With the HAM6 +X door off we did an initial inspection of HAM6, looking for anything that could have caused the pressure spikes seen in 78346, 78432.
There was discoloration on the fast shutter, see lower half of the -X part of the "fast shutter cap" and viton piece: part (4) and (10) of D1003318. Photos attached. This was the only thing we could see out of the ordinary.
From the Feb 2024 HAM6 closeout photos in 75791, this photo shows the fast shutter and no discoloration can be seen.
We'll plan to inspect the fast shutter when closed today.
Tagging for EPO.
Fri Jul 19 08:04:09 2024 INFO: Fill completed in 4min 6secs
Gerardo confirmed a good fill curbside.
TITLE: 07/19 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 8mph Gusts, 5mph 5min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.11 μm/s
QUICK SUMMARY:
IFO currently DOWN for maintenace.
LVEA is currently LASER SAFE
Temps in the LVEA have come back down from their peak yesterday.
Expected work today (according to DCC Doc E2400260) :
H6 - Initial inspection of OM1, Refl Beam dump, cables, PDs, beam dumps, etc
H5 - Lock ISI
H5 - Remove OFI Black glass panel shroud pieces from at least +X side and roof. TAKE CARE TO INVESTIGATE any clipping or anything out of nominal.
Remove HAM6 -X DOOR
H6 - Lock ISI
Pull CC wafers reachable in both chambers
H5 - Initial inspection of OFI and SRM optic surfaces, cables, beam dumps, etc
FTIR sample XX areas on table and around any damage areas (5 sample vials).
H5 - Transition to Laser Haz
Setup AUX laser systems, prioritize HAM5 alignment laser
Edit : Neil knows how to make links, now. Tony and Camilla were instrumental in this revelation.
This is an update to my previous post (Neil’s previous post on this topic) about looking for possible explinations why similar seismic wave velocities on-site may or may not knock us out of lock.
The same channels are used in addition to:
SEI- * ARM_GND_BLRMS_30M_100M
SEI- * ARM_GND_BLRMS_100M_300M
Where * is C, D, X, or Y.
I have looked at all earthquake events in O4b, and only ones which knocked us out of lock. This is to simplify the pattern search, for now. Here are the results.
Total events : 29
Events with ISI y-motion dominant : 11 (30-100 Hz) : 8 (100-300 Hz)
Events with ISI x-motion dominant : 3 (30-100 Hz) : 0 (100-300 Hz)
Events with ISI z-motion dominant : 9 (30-100 Hz) : 19 (100-300 Hz)
Events with ISI xy-motion dominant : 1 : 0 (Both axes are similar in amplitude.)
Events with ISI yz-motion dominant : 0 : 1
Events with ISI xz-motion dominant : 0 : 1
Events with IS xyz-motion dominant : 5 : 0
Total SEI- * ARM recorded events : 8
CARM dominant events : 7 : 8
C/XARM dominant events : 1 : 0
Conclusion is that in the 30-100 Hz band, it is equally likely to have either z- or y-axis motion be dominant. In the 100-300 Hz band, the ratio is about 1:2 for z and y motion being dominant during lockloss.
Clearly, common modes are a common (^_^) cause of lockloss.
Note that velocity amplitudes should be explored more.
Today's activities: - The purge air dew point was measured at the purge port: (9:15 am) -42.5 deg C - The relay tube was vented with Nitrogen, and was taken off: at the HAM5 side, the dog leg stayed, and at HAM7, one bellows was left there - The HAM5/HAM6 annulus system was vented with Nitrogen, the AIPs have been turned off - HAM5+X, HAM5-X, HAM6+X doors have been removed. Both HAM5 doors' inner O-ring are needed to be replaced, as they are damaged and worn out - IP19 was valved out at the top of HAM7 - HAM7 was vented, but all doors are staying in place for now - The pressures outside the corner have been stabilized now, and consistently dropping The pressures: - Corner, HAM7: atmosphere - Y-manifold: 3E-8 Torr - CP1: 3.9E-9 Torr - CP2: 5.3E-9 Torr
Mitchell R, TJ S.
We removed the one +X panel, three of the top panels, the +Y panel, and one on the -X side. This should give enough room to work on the OFI below and get power meters into all places needed.
Some panels had minor blemishes on them, I'll have to reference the photos we took when installing to make sure they aren't new.
Dust counts when entering chamber were 0's or 10. They were checked periodically with similar readings.
Tagging for EPO.
On a Tuesday a couple weeks back I went to HAM8 and looked at connections between the shield pins for all of the single axis seismometers on HAM8, both at the rack and at the feedthru on the chamber. For the H1 seismometer I found that pin 9 (labeled as GS13-2 Sig+ on D1002706) is grounded to pin 5, which is the shield, this would explain why the sensor has a gain of 1/2 compared to the other seismometers. None of the other GS13s show this shield connection to signal. However, 2 of the L4C pairs have multiple wires connected to the shield, I haven't run down what they are yet. All of the wires that are connected to shield are connected at both the rack and the flange, so the issue is somewhere in vacuum. Can't really tell more at this point without opening the chamber. I plan to check HAM7 at some point, but that is a borrow from 3ifo.
Mitch and I did some tests on what spare A+ cables we could find in the staging building, 2 D1000227 pigtails and 2 220(?) 25pin extensions. We couldn't find or cause any connections between the shields and signal wires, but it wasn't an exhaustive test. I'm also huddling some GS13s on the table, I will try to see if there are any wire-shield connections with the cables that are plugged into those sensors.
TITLE: 07/18 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:
IFO is in CORRECTIVE MAINTENANCE for VENTING
Productive day where we found the culprit (yet to be seen if there are more) to our OFI issues in the form of a burn on the KTP Optic of the OFI (alog 79223). After this point, there were impromptu meetings discussing how to proceed. A slight shift of priorities was announced and the check-list is as follows (E2400260):
WED JULY 17
THUR JULY 18
FRI JULY 19
Aditionally, all TFs for pe-vent suspensions have submitted ALL_TF and comparison TF reports as comments to their initial alogs: alog 79189, alog 79188, alog 79198, alog 79202
These plans are of course tentative and depend on ongoing decisions in this living (and breathing) document. Well done to the quick, efficient and safe vent crew!
THIS JUST IN: Approximately 3s before hitting enter, the vent crew came back with more pictures of backsplashed debris from the two burn spots in the OFI. Stay tuned for more (alogs).
LOG:
Start Time | System | Name | Location | Lazer_Haz | Task | Time End |
---|---|---|---|---|---|---|
14:48 | FAC | Karen, Kim | LVEA | N | Technical Cleaning | 15:48 |
15:53 | EE | Fil, Camilla | LVEA | N | Pulling off HAM6 Cameras | 16:53 |
16:10 | FAC | Chris, Eric | HAM6 | N | Breaking torque on HAM6 Door Bolts | 19:20 |
16:12 | FAC | McCarthy | HAM6 | N | Ensuring Safety during door work | 18:12 |
16:14 | FAC | Bubba G | EX & EY | N | Resuppling First Aid Kits | 17:26 |
16:16 | VAC | Jordan, Tyler | HAM6 | N | HAM6 Door Bolt Torque breaking | 19:38 |
16:18 | VAC | Travis, Gerardo | LVEA | N | Relay tube VAC work & HAM6 Door crew work. Travis out 19:15UTC | 19:31 |
16:31 | FAC | Tyler | FCES | N | Camera Acquisition | 16:52 |
16:33 | VAC | Jason | LVEA | N | Aux lasers for LVEA vent team | 16:42 |
16:44 | EE | Keita | LVEA | N | Fil BNC Cable HAM6 | 17:10 |
16:57 | FAC | Kim, Karen | LVEA | N | Technical Cleaning | 17:57 |
16:58 | FAC | Fil | LVEA | N | Interlock | 17:58 |
17:11 | SQZ | Keita, Jennie | Optics lab | Local | Work on HAM5/6 laser | 19:38 |
17:23 | SQZ | Camilla | Optics lab | Local | Check if team has all the parts they need | 18:40 |
17:45 | CAL | Tony | PCAL lab | LOCAL | Gather stuff | 18:03 |
18:41 | SQZ | TJ | Optics Lab | Local | Part search Part 2 | 19:08 |
18:41 | FAC | Richard | LVEA | N | Supervision | 19:01 |
18:42 | PCAL | Rick, Guest | LVEA | N | Walking Tour | 19:20 |
19:05 | Betsy | LVEA | N | Check on crew | 19:25 | |
19:39 | EE | Fil | CER | N | ISI WD Cable Reset | 20:28 |
19:43 | PCAL | Rick, Dripta, Emmanuel, Shingo, Dan | EY | YES | PCAL Measurements | 21:54 |
20:23 | FAC | Tyler | LVEA | N | HAM5 -X Door Removal Prep | 21:51 |
20:28 | VAC | Chris, Jordan, Travis | LVEA | N | HAM5 -X Door Removal | 21:51 |
21:32 | SUS | Mitchell, Betsy, TJ, Sheila | LVEA | N | HAM5 Door + OFI | 23:32 |
22:26 | Oli | LVEA | N | Parts dropoff | 22:30 | |
22:42 | Ibrahim | LVEA | N | Sensor calibration | 22:45 | |
23:28 | PCAL | Tony, Emmanuel | PCAL Lab | Local | LHO PS4 PS5 Measurement | 00:28 |
Spare optic SRM07 arrived at LHO yesterday from LLO, after prisms were bonded to it's sides (see LLO alog 71969 for details). After inspecting the optic in bonding lab, I started preparing for bonding the magnet-standoff on the AR side. At first I prepared 8-10 magnet-standoff of both north and south polarity. The magnets were glued to the standoffs using Masterbond EP-30 - as per assembly drawing D0902432_V2.
The optic with AR side facing up (arrow at the top of the optic points towards the HR side) was placed on the gluing jig and aligned with the scribe lines. Once the edge of the optic was well aligned with the jig, metal plungers with the magnet-standoffs were inserted inside (the jig) - after applying the Masterbond EP-30 to the bottom tip of the standoffs using a pin (for reference see pic here). This set up was left for curing for 24hrs approximately, following which the jigs were removed. Given below are the details with pictures for reference,
- SRM07 arrived at LHO in pelican case - image01.
- optic inside the transport can - image02
- optic placed on the optical bench for inspection - image03
- Metal jig were placed on top of the AR side of the optic and aligned with the scribe lines and the optic edge (locked with stops having silica tip ends)- image04
- magnet-standoffs with plungers inserted into the jigs - image05
- magnet standoff prepared in lab - image06
- jigs removed and SRM07 with magnets glued to its AR side is visible - image07 and image08
- Optic with labels showing the four magnets and their polarity - image09 - see controls arrangement poster for reference.
Tagging for EPO.
Looks like there is visible damage on the KTP optic of the OFI.
TBC...
Betsy, Sheila, TJ, Mitchell, Camilla
On second inspection, after TJ and Mitch removed some of the OFI shroud 79227, you can clearly see two crater holes in the KTP wedge on the input (SRM) sideG2100316 OFI doc. The output (OMC) side of the KTP wedge looked smooth. Photo and photo.
There is splatter on the Fused Silica wedge optic, holder and surrounding beam dumps facing the KTP crater holes. Photo and photo. Maybe there was more splatters on the KTP holder too.
Photos of the SRM AR surface looked fine, but it was hard to see: photo
Zoomed out photos of the OFI with shroud removed to aid with planning: here and here.
Additional photos from everyone on googledrive here.
Attached is a view looking through the OFI from the SRM side back towards HAM6. As well as the two crater spots, you can see the black dots of splatter on the FS wedge.
Tagging for EPO.
WP 11989
With HAM6 and HAM7 vented, the Fast Shutter, OMC PZT, PSAM and HAM7 Piezo were powered on. Both high voltage interlock chassis are bypassed from the vacuum interlock system. Shortening plugs were installed to enable the power supplies to turn on. This will need to be removed before pump down. WP will be left open.
The fast shutter chassis in ISC-R3 is powered on but the enable HV switch needs to be toggled up. See attached picture.
Fil, Dave:
Fil tested the corner station ITMY, ITMX HWWDs by disconnecting one of the satellite amp input connectors for a few seconds on each. The HWWDs went into LED-low-current mode (8) as expected.
We performed this test because over the past week ITMY and ETMX HWWDs have been very quiet, whereas ITMX and ETMY remain noisy. I cannot find any correlation in the main mass top drives signals and these quiet times.
At Jims recommendation, I put the corner station ISIs into damped around 17:45 UTC. HAMs 2, 3, 4, and BSCs 1, 2, 3.
As part of the TF A-Team, SR2 and SR3 TFs can be found here under today's date - 07-17-2024
SR2:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM1/Data
SRM:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SRM/SAGM1/Data
PDFs to be posted, edited, commented in soon.
Find attached both the TF Model Comparisons and the ALL_TF Model and Previous Measurements Comparisons
allhsts comparisons: /ligo/svncommon/SusSVN/sus/trunk/HSTS/Common/Data
SRM All_TFs: /ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SRM/SAGM1/Results
SR2 ALL_TFs: /ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM1/Results
SUMMARY: Transfer Functions COMPLETED for ZM6, OM1, & OM2. Leaving in DAMPED guardian state for vent. Will post matlab plots in a comment to this alog later.
Joined team of others (Ibrahim, Jeff, Rahul, RyanC) in getting SUSpension transfer functions in preparation for upcoming vent. We split up the work amongst us. I took on ZM6, OM1 and OM2.
7/18/24 Update NOTE: OM3 measured by Ryan C, OMC measured by Rahul. Their results are posted in a comments below!
Instructions for this work is at: https://awiki.ligo-wa.caltech.edu/wiki/Suspensions/OpsManual/TFs/DTT
For TODAY, this is what I did:
Here are the locations of the files noted above:
Will leave all of these SUSpensions in their DAMPING guardian state (vs ALIGNED).
I ran the first analysis code for the OMs.
Attached are the Matlab-generated plots for ZM6 (with measurements I ran yesterday).
(Ryan already made the plots for OM1 & OM2 which I measured yesterday--Thanks!)
I should note this was my first time running through this procedure for taking SUS transfer functions. I had a few issues which came up (mainly svn-related), but got through some of this yesterday with Jeff's help, and Erik helped me this morning with other svn issues, but for these issues, I opted to not run an SVN update since there was a note for a "conflict". So I skipped the svn steps for plotting.
The Latest H1SUSZM6_M1_ALL_TFs.pdf is now availible
If you want to know where this lives on the CDS machines it can be found here:
/ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/ZM6/SAGM1/Results
I have taken the in-vacuum measurements for OMC (HAM6) and they look great - see screenshots attached below.
The seismic state of HAM5 during this measurement was, ISI_DAMPED_HEPI_OFFLINE and the HEPI was locked yesterday. I put SR3 to DAMPED, made sure the damping outputs were off and the TEST outputs were on. Overall it looks fairly close to the model.
On Roll I saw an extra peak around ~1.04 Hz, and Verticle around ~1.5 Hz (cross coupling from yaw?).
The templates are saved at /ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/SR3/SAGM1/Data
Jennie W, Sheila,
We turned off the 9 and 45 MHZ sideband EOMs and unplugged the 118 MHz modulation at the PSL racks. See this alog for how to do this.
We locked the IMC and mis-aligned ITMX.
DC centering loops 3 and 4 were turned on.
Sheila took the OMC lock guardian to PREP OMC scan and turned on the OMC ASC.
We waited for this to converge then turned it off.
We turned input power up to 10W from 2W and then locked the OMC in length manually by using the PZT offset slider to search for a high peak ~ 15mA.
After finding it we turned on the locking with a gain of 24 and the boost and int filters on (we checked the settings we needed in the guardian as we couldn't get the OMC guardian to lock it for us).
Then we turned off the OMC ASC.
We tuned up the OM3 and OMC alignment slightly to maximise the power on OMC-DCPD_SUM_OUTPUT and minimise it on OMC-REFL_A_LF_OUT16.
OM3 was moved down in yaw only from -108 to -117 and OMC was moved down in yaw from 210.5 to 195.5 and down in pitch from 350.4 to 340.4. The final values for the sliders are here.
Quiet time locked after aligning 16:21:03 UTC - 16:24:13 UTC
OMC-REFL_A_LF_OUT16 = 0.652644 mW
OMC-DCPD_SUM_OUTPUT = 15.6162 mA
Quiet time unlocked 16:25:31 UTC -16:27:35 UTC
OMC-REFL_A_LF_OUT16 = 30.106 mW
OMC-DCPD_SUM_OUTPUT = 0.000456763 mA
We took the IMC guardian offline and shuttered the green light going into both arms at the ISC tables, and with ISC_LOCK guardian in idle so it wouldn't keep trying to relock IMC.
Quiet time dark measurement 16:43:38 - 14:46:19 UTC
OMC-REFL_A_LF_OUT16 = -0.0132979 mW
OMC-DCPD_SUM_OUTPUT = -0.00106226 mA
The scan template is saved as /ligo/home/jennifer.wright/Documents/OMC_scan/2024_04_16_OMC_scan.xml
With the references for the time series of the three pertinent channels as:
Ref 0 OMC-DCPD_SUM_OUT_DQ
Ref 1 OMC-PZT2_EXC
Ref 2 OMC-PZT2_MON_DC_OUT_DQ
I ran Sheila's code from this entry, altered with the measured input/output coupler transmission of the current OMC which can be found on Page 116 on LIGO-T1500060.
The output gives this for the cavity parameters:
Power on refl diode when cavity is off resonance: 30.138 mW
Incident power on OMC breadboard (before QPD pickoff): 30.589 mW
Power on refl diode on resonance: 3.879 mW
Measured effiency (DCPD current/responsivity if QE=1)/ incident power on OMC breadboard: 59.5 %
assumed QE: 100 %
power in transmission (for this QE) 18.203 mW
HOM content infered: 9.763 %
Cavity transmission inferred: 66.439 %
predicted efficiency () (R_inputBS * mode_matching * cavity_transmission * QE): 59.509 %
omc efficency for 00 mode (including pick off BS, cavity transmission, and QE): 65.948 %
round trip loss: 3504 (ppm) Finesse: 335.443
I will cross-check the HOM content inferred by analyaing the C02 mode height from a cavity scan.
The mode-matching inferred from the height of the carrier 02 mode vs. the carrier 00 mode from the scan is 0.0983 mode mis-match = 9.83%.
The mode scan fit and the C02/C20 fit are attached.
The code is on labutils /dev branch
The code for the full scan can be ran using:
python OMCscan_nosidebands9.py 1397320410 80 "Cold OM2, 10W PSL, pre-output loss" "single bounce" --verbose -m -o 2
The code for the C02 fitting can be done using:
fit_two_peaks_no_sidebands9.py
Where the blue trace is the data, the orange is the fit, and the purple is the function plotted with the inital guesses for the fit parameters as a cross-check.
Daniel, Sheila
We turned off the 9 Mhz, 45 MHz, and 117 MHz sidebands in order to do an OMC loss measurement. We used a single bounce beam off of ITMX, with 10W input from the PSL. We spent some time trying to improve the alignment before making OMC scans.
locked: 1370711576 (OMC REFL avg 3.51mW, OMC DCPD sum 15.23mA)
unlocked: 1370711782 (OMC REFL avg 24.73 mW, OMC DCPD sum 0.078 mA)
OMC scan start: 1370712036 duration 100 seconds (2nd order modes are roughly 8% of the 00 mode).
shutter blocked: 1370712337 (OMC REFL avg -0.030 DCPD SUM 8e-4 mA).
Jennie Wright plans to analyze this data to estimate OMC losses.
Here are the plots of ASC-AS_C_NSUM, OMC-QPD_A_NSUM, OMC-QPD_B_NSUM and OMC-REFL_A_LF, during these measurements. ASC-AS_C_NSUM shows between 22.8 and 32.1mW, OMC-QPD_A_NSUM 23.4mW, OMC-QPD_B_NSUM 23.0mW, and OMC-REFL_A_LF 24.8mW. According to Keita OMC-REFL_A_DC has an incorrect calibration and shows 25.2mW. The average of the 2 QPDs would be 23.2mW, which is about 6.5% lower than 24.8mW.
Second screen shots shows a time when the IMC was unlocked. The DC offsets are in the 10s of uW at most.
Using data from the scan I adapted labutils/OMCscan class to plot the fitted scan and adapted labutils/fit_two_peaks.py to fit a sum of two lorentzians functions for distinguishing carrier 20/02 modes.
The first graph is the OMC scan plot, the second is the curvefit for the second order carrier modes.
We expect the HOM spacing to be 0.588 MHz as per this entry and DCC T1500060 Table 25.
The spacing for the modes measured is 0.592 MHz.
From the heights of the two peaks this suggests mode-mismatch of the OMC to be C02+C20/C00 = (0.83+1.158)/(15.32+0.83+1.158) = 11.0% mode mis-match.
From the locked/unlocked powers on the OMC REFL PD the visibility on resonance is 1-(3.51+0.03/24.73+0.03) = 85.7% visibility.
If the total loss is 14.3%, this implies that the other non mode-matching losses are roughly 1.3%.
To run the OMC scan code go to
/ligo/gitcommon/labutils/omc_scan/
and run
python OMCscan_nosidebands.py 1370712036 100 "Sidebands off, 10W input" "single bounce" --verbose --make_plot -o 2
in the labutils conda environment and on git branch dev.
To do the double peak fitting run:
python fit_two_peaks_no_sidebands.py
in the labutils conda environment and on git branch dev.
These scans were done with OM2 cold.
For comparison with new OMC measurements I used Sheila's code to process the visibility, but updated dit to use nds2utils instead of gwpy as I was having trouble using it to get data.
The code is attached and should be run in the nds2utils conda environment on the CDS workstations.
Power on refl diode when cavity is off resonance: 24.757 mW
Incident power on OMC breadboard (before QPD pickoff): 25.239 mW
Power on refl diode on resonance: 3.525 mW
Measured effiency (DCPD current/responsivity if QE=1)/ incident power on OMC breadboard: 70.4 %
assumed QE: 100 %
power in transmission (for this QE) 17.760 mW
HOM content infered: 13.472 %
Cavity transmission infered: 82.111 %
predicted efficiency () (R_inputBS * mode_matching * cavity_transmission * QE): 70.367 %
omc efficency for 00 mode (including pick off BS, cavity transmission, and QE): 81.323 %
round trip loss: 1605 (ppm)
Finesse: 371.769