oli.patane@LIGO.ORG - posted 20:07, Friday 03 October 2025 (87291)
Ops EVE Midshift Status
Observing at 151 Mpc and have been locked for over 6.5 hours. Nothing to report
Observing at 151 Mpc and have been locked for over 6.5 hours. Nothing to report
Jennie W, Keita,
Since we don't have an easy way of scanning the input beam in the vertical direction, Keita used the pitch of the PZT steering mirror to do the scan and we read out the DC voltages for each PD.
The beam position can be inferred from the pictures setup - see photo. As the pitch actuator on the steering mirror is rotated the allen key which is in the hole in the pitch actuator moves up and down relative to the ruler.
height on ruler above table = height of centre of actuator wheel above table + sqrt((allen key thickness/2)^2 + (allen key length)^2) *np.sin(ang - delta_theta)
where ang is the angle the actuator wheel is at and delta_theta is the angle from the centre line of the allen key to its corner which is used to point at the gradations on the ruler.
The first measurement from our alignment that Keita found yesterday that minimised the vertical dither coupling is shown. It shows voltage on each PD vs. height on the ruler.
From this and from the low DC voltages we saw on the QPD and some PDs yesterday Keita and realised we had gone too far to the edge of the QPD and some PDs.
So in the afternoon Keita realigned onto all the of PDs.
Today as we were doing measurements on it Keita realised we still had the small aperture piece in place on the array so we moved that for our second set of measurements.
The plot of voltage with ruler position and voltage with pitch wheel angle are attached.
Keita did a few more measurements in the verticall scan after I left on Friday, attached is the updated scan plot.
He also then set the pitch to the middle of the range (165mm on the scale in the graph) and took a horizontal scan of the PD array using the micrometer that the PZT mirror is mounted on. See second graph.
From the vertical scan of the PD array it looks like diodes 2 and 6, which are in a vertitcal line in the array, are not properly aligned. We are not sure if this is an issue with one of the beam baths through the beamsplitters/mirrors that split the light onto the four directions for each vertical pair of diodes or if these diodes are just aligned wrongly.
TITLE: 10/03 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 149Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY: One lockloss due to an earthquake today that kept H1 down for a while, but relocking after that was mostly straightforward; not much else to report today. H1 has now been locked for 3 hours.
LOG:
| Start Time | System | Name | Location | Lazer_Haz | Task | Time End |
|---|---|---|---|---|---|---|
| 22:52 | SAF | Laser HAZARD | LVEA | YES | LVEA is Laser HAZARD | Ongoing |
| 14:38 | FAC | Randy | X-arm | N | BT inspection | 19:37 |
| 17:34 | ISC | Keita | Opt Lab | Local | ISS array work | 19:26 |
| 17:41 | PEM | Anamaria | CER | N | Checking an accelerometer | 17:44 |
| 17:50 | JAC | Corey | JAC Lab | N | JAC table work | 20:29 |
| 18:23 | ISC | Jennie | Opt Lab | Local | ISS array work | 19:26 |
| 18:48 | PEM | Robert, Anamaria, Alicia, Rene | LVEA | - | PEM things | 19:26 |
| 19:26 | PEM | Robert | LVEA | - | Placing shaker near BSC8 | 19:42 |
| 21:33 | JAC | Corey | JAC Lab | N | JAC table work | 23:07 |
| 21:34 | ISC | Keita, Jennie | Opt Lab | Local | ISS array work - Jennie out @ 22:08 | 22:24 |
TITLE: 10/03 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 20mph Gusts, 15mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.19 μm/s
QUICK SUMMARY:
Observing at 153 Mpc and have been Locked for 2.5 hours
Robert, Anamaria
Following up on tests done at L1, we wanted to do the same tests at H1 and compare. We see similar large shelves when we shake RX and RY at 0.2 Hz. This mechanism is not directly limiting DARM since we have to inject a lot to see it, but it allows us to estimate how much light is around the BS area available for scattering into DARM.
The stranger difference between the sites is that the ratio of the first shelf to the second shelf for H1 is much smaller, circa 10, so implies a second reflective path that's still fairly in line (eg like the R0 ESD reflections).
I drove 100 cts into the the corresponding ISO filter bank.
RX injection start: Oct 2 17:41:39 utc
duration: 8 min
RY injection start: Oct 2 17:58:20 utc
duration: 2 min (lost lock shortly after so weren't able to get more data)
dtts can be found in /ligo/home/anamaria.effler/ddt/ with suggestive names. I had also copied over the equivalent L1 dtts in the same directory.
Robert will folow up with some more tests.
Closes FAMIS#26659, last checked 87238
HAM5, HAM6, HAM8, ITMX ST1, ITMY ST1 - bit of extra noise between 5-8 Hz in all sensors
BS ST1 - excess noise between 5-8 Hz in vertical sensors
ETMX ST1 - excess noise between 20-30 Hz in V3
Closes FAMIS#27426, last checked 87179
Corner Station Fans (attachment1)
- All fans are looking normal and within range.
Outbuilding Fans (attachment2)
- All fans are looking normal and are within range. You can see when EX fan 2 was turned off three days ago due to its noise increasing (issue fixed).
FAMIS 27397
Laser Status:
NPRO output power is 1.861W
AMP1 output power is 69.83W
AMP2 output power is 138.5W
NPRO watchdog is GREEN
AMP1 watchdog is GREEN
AMP2 watchdog is GREEN
PDWD watchdog is GREEN
PMC:
It has been locked 10 days, 2 hr 57 minutes
Reflected power = 25.18W
Transmitted power = 104.1W
PowerSum = 129.3W
FSS:
It has been locked for 0 days 2 hr and 15 min
TPD[V] = 0.5335V
ISS:
The diffracted power is around 3.9%
Last saturation event was 0 days 4 hours and 21 minutes ago
Possible Issues:
PMC reflected power is high
Fri Oct 03 10:07:45 2025 INFO: Fill completed in 7min 41secs
I have written a new script called guardian_modified_not_loaded which lists those Guardian nodes using a source file which has been modified but not loaded into that node.
The reason this is important is that when a guardian node is restarted, it reads the latest userapps files which could differ from what was being used before the restart.
Running the script today, for example, shows that lscparams.py and sqzparams.py, which are used by many nodes, have been modified and only loaded into a few nodes.
We plan on running this script regularly, and especially before a scheduled reboot of h1guardian1.
Current stats are: number of source files = 270, number of guardian nodes = 173, total nodes file count = 1761
Loaded 270 opt/ file checksums from /opt/rtcds/lho/h1/data/guardian_files/current
Loaded 173 nodes from /opt/rtcds/lho/h1/data/guardian_files/current.yaml
No node_exceptions.yaml file found - no exceptions applied
================================================
Node Status File
================================================
ALS_COMM NOT LOADED lscparams.py
ALS_XARM NOT LOADED lscparams.py
ALS_YARM NOT LOADED lscparams.py
CAMERA_SERVO NOT LOADED lscparams.py
H1_MANAGER NOT LOADED lscparams.py
IMC_LOCK NOT LOADED lscparams.py
INIT_ALIGN NOT LOADED lscparams.py
ISC_DRMI NOT LOADED lscparams.py
LASER_PWR NOT LOADED lscparams.py
LOCKLOSS_SHUTTER_CHECK NOT LOADED lscparams.py
OMC_LOCK NOT LOADED lscparams.py
SEI_CONF NOT LOADED lscparams.py
SEI_ENV NOT LOADED lscparams.py
SQZ_ANG_ADJUST NOT LOADED sqzparams.py
SQZ_CLF_LR NOT LOADED sqzparams.py
SQZ_FC NOT LOADED lscparams.py
SQZ_MANAGER NOT LOADED lscparams.py
TCS_ITMX_CO2_PWR NOT LOADED lscparams.py
TCS_ITMY_CO2_PWR NOT LOADED lscparams.py
TEST NOT LOADED lscparams.py
THERMALIZATION NOT LOADED lscparams.py
NOT LOADED sqzparams.py
TMS_SERVO NOT LOADED lscparams.py
VIOLIN_DAMPING NOT LOADED lscparams.py
================================================
24 file(s) NOT LOADED
I have added a seismic activity bar, similar to the wind speed bar, to the upper right of the CDS Overview. Attached shows the bar during the current earthquake.
Similar to the wind speed, the bar fills from the left, start green then gets increasingly red.
This bar is logarithmic, each point is approximately a factor of about 2.5 from the last. The range is 1.0e+01 to 1.0e+05 BLRMS.
The bar is comprised of circles ("little earths") rather than squares.
DTS Environment Repositioned On CDS Overview.
To make room for the Seismic bar, I removed the DTS environment section. This has now been added back as a "system widget" in the FMCS section (see attached).
The "DTS ENV" block will turn RED if the server room temperature exceeds 80F. The block will turn MAGENTA if the dts_env_ioc GPS time falls behind by 10 minutes or more.
Clicking on the "DTS ENV" block will open the DTS Detail MEDM (attached).
Lockloss @ 16:44 UTC after 12.5 hours locked - link to lockloss tool
M6.1 EQ out of Kamchatka followed by a M5.1 aftershock. I dropped observing at 16:26 UTC as it was coming in to engage the hi-gain ASC, which seemed to help for a while until the aftershock hit and peakmon reached about 2300 counts. Holding H1 in 'DOWN' until the ground settles.
H1 back to observing at 20:34 UTC. Ran an alignment after the ground motion calmed down, then while locking, two locklosses during DRMI acquisition made for a longer overall relock time. MICH_FRINGES was needed after the second DRMI lockloss.
Had issues with FAMIS, so was not able to check this until today. Looks like the SUS Charge measurements ran this past Tuesday morning.
(A procedure note: when I ran the printing command, it would generate the ETMx plot, but that was it.....until I saved the plot to the desktop and then closed the generated .png plot. Then it would continue with the other plots (one at a time)---took me a bit to figure that out!)
Attached are the plots for all four Test Masses. Closing FAMIS 28425.
TITLE: 10/03 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 3mph Gusts, 2mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.21 μm/s
QUICK SUMMARY: H1 has been locked for over 10 hours. S251003at earlier this morning at 13:23 UTC.
S251003at from this morning was retracted.
Also ran range comparison checks comparing this lock stretch to the last as our range is a bit better. Seems like DARM looks better overall above ~60Hz; Sheila says this is probably just because the squeezer is "better" today. Report attached.
TITLE: 10/03 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
INCOMING OPERATOR: Corey
SHIFT SUMMARY: Observing at 155 Mpc and have been locked for over 30 minutes. We recovered from the lockloss really quickly (59 minutes!) and I didn't need to intervene.
LOG:
23:30 UTC Observing and locked for almost 4 hours
01:59 GRB-Short E606552
03:22 Lockloss
04:21 NOMINAL_LOW_NOISE
04:24 Observing
Yesterday I went into the optics lab and re-measured the coupling between input beam motion and PD array. While taking measurements I noticed that the injection could not be seen on the AC readouts of the PDs (example) so I tuned the temperature of the laser via changing the resistance of the controller, I went from ~10kOhms up to 13 kOHms and down to 8kOhms and while I found places where the noise reduced see example of noisy trace here, I couldn't find anywhere with the controller where the trace renamed stably in the non-noisy state. I then decided to tune the pump current down from 130mA to ~100mA and eventually found a somewhat stable place. I still had to wait through some periods of noise to trigger the measurement of the PDs.
I alos increased the modulation ampltitude to 80 mVpp. The counts on the QPD LCD readout were 10672, see image.
When the laser is in its quiet state the AC PD traces should comfortably fit on the screen of the osclloscopes with a 5mV scale, with the laser noisy this is more like 100mV, I also use 100mV scale for the QPD, I didn't change it when I reduced the noise on the laser.
The noisy state for the QPD outputs is here, the quiet state is here.
For each measurement I used a capture range of 400ms on the time axis of the scope and 125 000 samples selected on the 'ACQUIRE' menu.
The final measurements are:
PD 1 - 4 measured at AC: T0012ALL.CSV
PD 5 - 8 measured at AC: T0014ALL.CSV
QPD X, Y and SUM channels measured at AC: T0013ALL.CSV
The two DC measurements are going to be averaged so I didn't wait for a quiet time to measure them.
PD 1 - 4 measured at DC: T0011ALL.CSV
PD 5 - 8 measured at DC: T0010ALL.CSV
To save you need to click on the menu button and change the resolution to be'Full', the format to be CSV and the channels captured to be 'ALL', the file number will roll over every time you save so you don't need to enter it manually.
The code to produce this plot is in my optics lab code repo.
The graph of the TF from horizontal dither on the input mirror to horizontal dither across the array, shows that we are not getting much coherent modulation of the light intensity on the PDs at 100Hz which is the dither frequency. Either my code is wrong or I need to increase the dither amplitude for the mirror.
The maths to work this out was
A time series = abs(dither in direction horizontal to bench on QPD in V)/ (motion horizontal to bench volts on QPD/mm moved horizontal to bench on QPD)
B time series = AC voltage on each PD / mean of DC voltage on each PD
TF = CSD (B, A) / PSD (A, A)
I used gwpy for the calculations this time.
The attached plot shows each PD in the array as a different colour with magnitude on the top and phase on the bottom.
We realised in the analysis that we should be using :
H_amp on QPD = Xcos theta + Y sin theta where theta is the angle between the X axis of the QPD and the horizontal scan direction of the beam worked out from our previous calibration measurments, 14 degrees.
This gives a different value for the couplings. All the PDs other than PD6 did not have coherences 0.9 or over so I only attach the final TF for PD6. We increased the dither amplitude after this to improve the measurement of the other PDs.
Camilla, Sheila
We did a series of quick measurements related to filter cavity backscatter, a follow up with plots will come soon.
Injection for linear coupling (varies from day to day, we are repeating to see how much it changes, 1st screenshot):
Fringe wrapping (scattered amplitude seems slightly lower than in 2024 when moving ZM2, slightly higher when moving ZM5):
Open loop gain (also varies from day to day):
FC2 M1/M3 cross over:
Here's the plot of the fringe wrapping measurements in displacement units. It can be compared to a similar measurement made on ZM4 + 5 at LLO: 60856. Over email Peter asked some questions about the power levels needed to explain this.
Power level heading towards HAM7 from OFI:
The power on the DCPDs is 47mW, and there is 12pW retro-reflected off the filter cavity, so the total isolation provided by OFI + SFI2 + SFI1 is 2.5e-10 in power ratio, or 96dB. The OFI isolation ratio was measured to be 43dB in 79379. If this is true it would imply that one of the SFIs is providing less than the 30dB isolation assumed in T1800447, and we should have 2uW of carrier light headed towards SFI2.
Our readback of the 1% pick off of light from the interferometer heading towards SFI2, B:PD1 (OFI PD A) says that we have 0.03mW on it, meaning 3mW from the IFO going towards SFI2, about 1mW of this would be carrier based on (87114),which seems too high.
The responsivity of this PD was checked in 60284, and later double checked because it seemed low (the settings are still the same). The similar PD OFI PDB has a measured responsivity of 0.25A/W and the excelitas website lists a peak responsivity of 0.6A/W at 850nm for these PDs. (ffd-200h-si-pin) If we think that this calibration was mistaken and the real responsivity is more like OFI PD B, 0.25A/W, there is 0.72 mW of light from the OFI heading towards SFI2, ~240 uW of carrier, the OFI isolation would only be 23dB, and the SFIs must be providing something like 36 dB each.
Reflectivity:
If my interpretation of the fringe wrapping measurements into power are correct (12 nW of power is retroreflected from the path that includes ZM5), we are reflecting 50ppm of the carrier scattered toward HAM7 using the (recalibrated) 240uW value from OFI PDB, or 0.6% if we believe the isolation ratio measurement for the OFI and use the 2uW value. B:BS1 is a 1%, so the maximum reflectivitiy we could get from scatter in the B:PD1 path would be 0.01%. This means that the B:PD1 path can't explain the reflectivity needed if there is 2uW headed towards HAM7, and even if there is 240uW heading towards HAM7 this PD seems unlikely to explain the scatter, since it would need to reflect half the light that's incident on the PD. Camilla did alog the check of the alignment (and the beam dump catching the retro-reflection off this diode: 65006)
