If you need to reach the Control Room, please use TeamSpeak or MatterMost as the VOIP phone system is currently down at least in the OSB.
The HWUT picket has been down for a couple of days following some malfunctioning (Reported in [LHO aLog 79076]). We also saw the spurious signals at Stanford. This station's malfunctioning means the picket fence is not giving the intended forewarning for events originating in South/Central America.
We'll find a replacement picket soon and upload a revised code during the week.
Please post any additional requests in here, or feel free to message me directly.
This morning I took a dew point measurement of the corner station purge air, same setup like here. After measurement purge air was restored to all chambers.
Dew point measurement is -43.6 oC.
End of the day dew point measurement, -43.5 oC.
Closes FAMIS26274, last checked in alog79075
Laser Status:
NPRO output power is 1.825W (nominal ~2W)
AMP1 output power is 65.08W (nominal ~70W)
AMP2 output power is 138.7W (nominal 135-140W)
NPRO watchdog is GREEN
AMP1 watchdog is GREEN
AMP2 watchdog is GREEN
PDWD watchdog is GREEN
PMC:
It has been locked 12 days, 22 hr 28 minutes
Reflected power = 18.92W
Transmitted power = 108.0W
PowerSum = 127.0W
FSS:
It has been locked for 4 days 19 hr and 1 min
TPD[V] = 0.7416V
ISS:
The diffracted power is around 2.0%
Last saturation event was 5 days 20 hours and 13 minutes ago
Possible Issues:
PMC reflected power is high, its been drifting up since 07/09 (2 tuesdays ago).
Daniel resynced the MSR atomic clock to the timing system 16:27 Friday 19th July 2024 PDT.
I have removed my large tolerance of 0.9999 seconds which I had used to 'green up' the corner station timing system.
Tony mentioned that the Verbal alarm had requested a check of the PSL chiller. When I went in there, the water level was close-ish to the Min value. I added 125 mL of water.
Mon Jul 22 08:05:47 2024 INFO: Fill completed in 5min 43secs
Gerardo confirmed a good fill curbside.
The MSR UPS reported a power problem and went onto battery power for 3 seconds at 12:50:08 Sun 21 July 2024 PDT.
TITLE: 07/22 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 10mph Gusts, 7mph 5min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.07 μm/s
QUICK SUMMARY:
Verbals has a Check PSL Chiller alert from 14:22 UTC
IFO currently down for OFI maintenance.
Expected work today:
H6 - Continue inspection of WFS and shutter (take photo with fast shutter up).
Start setup AUX laser systems, prioritize HAM5 alignment laser
Confirm pointing still retained settings, oplev.
Using SQZ beam delivered from HAM7, make OFI Measurements in-situ:
Measure loss after each component inc. SRM with power meter.
Get Danny signoff on updated AUX SOP
Finish Setup AUX laser system in HAM5, use SR
Group mtg to determine OFI optic swap order of operations.
Sun Jul 21 08:06:17 2024 INFO: Fill completed in 6min 13secs
Over the past few days the MX weather station has been reporting diminished high temps. The attached plot shows all four out-building weather station temps, MX is in red.
Sat Jul 20 08:05:07 2024 INFO: Fill completed in 5min 3secs
TCs spiked to below the trip temps, but didn't flatten out. Pressure spike looks normal though.
After everyone was done at HAM5/6/7 chambers, and with soft covers on HAM5 and HAM6, I closed the purge air to HAM7 and closed the relay tube gate valve, aluminum foil was restored to cover the entire bellows port. HAM6 purge was closed via its purge valve.
HAM5 and HAM6 are currently being purged on a dialed back flow from the purge valve near HAM4 that feeds the ourput mode cleaner tube, soft covers are billowing out. Flow needs to be restored before any activities take place on any of the 3 chambers.
AUX laser that is to be injected in HAM5 from SRM HR side for later alignment work was prepared in the lab. It's smaller than the real IFO beam but it will do OK. In the 1st attachment, left is the SRM transmission path, green is measured in the lab, red is a fit, blue is the IFO. Assumption was made that the distance from SRM HR to the collimator telescope of the laser is 1.5m, it turns out that it's probably more like 2m or so, but it's not a huge deal. Right is the SRM reflection going to SR2.
We placed the telescope, a metal mirror and a BS roughly in place in HAM5 but didn't adjust it because SOP was not fully signed in time. We left these components inside and closed the chamber for today.
Tagging EPO.
TITLE: 07/19 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
SHIFT SUMMARY:
16:25 UTC HA:M4 and HAM7 ISI are Isolated.
HAM 7 Tripp. 18:02 UTC
Untripped an SRM watch dog.
Inchamber work started to happen today:
See Camilla's Alog shows that the Fast Shutter has been exposed to high temperatures and colorization.
Camilla and Jenne W. have been working on SQZ QPD centering. Seems like SQZr team now has light on their PDs again and will return on monday to continue their work.
HAM7 inchamber crew (TJ and Kieta) came out of chamber after installing the AUX laser but have not turned it on.
Gerardo is going into the LVEA to close up the HAM entries with temporary covers to minimize contamination.
Atomic clock failed again, Daniel is currently addressing that issue.
LOG:
| Start Time | System | Name | Location | Lazer_Haz | Task | Time End |
|---|---|---|---|---|---|---|
| 14:45 | RUN | Teachers | Y-arm | N | Teachers from LEXC running the arms. | 15:45 |
| 15:15 | VAC | Gerardo | LVEA | N | Purge air Skid & Dew point inspection | 15:37 |
| 15:45 | FAC | Karen & Kim | LVEA HAM5,6,7 | N | Technical Cleaning | 16:58 |
| 15:59 | Surf | Oli, Milly, Sabi | EY, MY, MX , EX | N | Plant Biology study | 18:13 |
| 16:01 | VAC | Gerardo | LVEA HAM7 | N | Preping HAM7 gate valve port work | 16:12 |
| 17:02 | SAFE | TJ | LVEA | Yes | Transitioning to LASER HAZARD & working on OFI | 17:37 |
| 17:09 | SAFE | LASER HAZARD | LVEA | YES | LVEA IS LASER HAZARD | 03:49 |
| 17:16 | VAC | Travis | LVEA | yes | Checking pumps | 17:27 |
| 17:34 | OFI | Betsy | LVEA HAM 6&7 | Yes | Working on OFI | 19:33 |
| 17:49 | PCAL | Francisco | PCAL Lab | Yes | Swapping the LHO PS4_PS5 Spheres for a measurement | 18:02 |
| 18:01 | SAFE | Richard | LVEA HAM 6&7 | Yes | Checking on OFI crew . | 18:14 |
| 18:02 | VAC | gerardo | LVEA | Yes | Checking VAC status in the LVEA | 18:15 |
| 19:09 | TOUR | Amber +5 | LVEA | YES | Tour into the LASER HAZARD LVEAwith teachers | 19:45 |
| 19:33 | OFI | Keita | Optics Lab | N | Wroking on OFI issue | 19:33 |
| 20:38 | OFI | TJ, Keita | Optics Lab & LVEA | Yes | Working on burnt OFI issues | 23:17 |
| 20:59 | SQZ | Camilla & Jenne, Naoki | SQZT7 & HAM5 | Yes | Working on SQZ beam alignment | 23:25 |
| 21:37 | OFI | Betsy | LVEA | Yes | Working on OFI issues. | 22:22 |
| 22:39 | Shutter | Betsy | Mx | N | Looking for fast shutter parts | 23:09 |
| 23:26 | VAC | Gerardo | LVEA | Yes | Putting covers over the HAM entrances and openings. | 23:56 |
This morning, TJ and I took FTIR samples of aras around the HAM5 OFI KTP burn event area and the HAM6 Fast shutter suspicious heat mark.
Report (and eventual results) posted to: https://dcc.ligo.org/E2400268
Relative Humidity reader on the table inside of HAM5 was reading 5% when we got in, 9% an hour into work with the cover open, 2 people.
Vicky, Camilla
Took ZM4,5,6, SRM alignment and PSAMs back to their values on 2024/07/17 20:18 to 20:23 UTC as in 79193. Plot here. We hope this will allow the SQZ beam through the OFI. SDFs for ZMs attached but not saved (incase we want to revert them if SQZ beam not seen), SRM optical align alignments were 2240, -3436 before as not svn monitored. SRM WD was tripped, Tony reset this.
SQZ OPO is seed dither locked but I can't see the most of the beam power on the SQZT7 diode. Vicky pointed out I should use the RLF QPDs to check for FC1, ZM1,2,3 pointing, they looked bad but there was some light on the QPDs, moved alignment sliders to get the FC1, ZM1,2,3 osems to be the same as 2024/07/17 20:18 to 20:23 UTC. This made the beam completely off the QPDs so I reverted, plot and sdf attached. We started walking the beam with FC1 and ZM3 as in 75509. Then Daniel asked if we had the TECs on...d'oh. after the TECs were turned on we had the QPDs saturating and I reverted all ZM1,2,3 and FC1 changes.
After lunch: Can reduce SEED power and check centering on QPDs. Can open SQZT7 and check the beam is going though the irises.
Jennie, Camilla, Naoki, TJ
Put SEED back to 75mW, IR PD still had 0.79mW (expect (1.3mW), we tried reverting ZM4,5 to the values this morning, before I corrected for the vent, this dropped the power further.
Only 0.7mW was making it to SQZT7. We dropped SEED power for 75mW to 5mW, started well centered on QPDA but -0.7 off QPDB_PIT, plot. We moved ZM3/FC1 to improve this to 0.88mW . We are normally +0.3 off in PIT, see attached. Later, once we were on SQZT7, Naoki noticed that this alignment wasn't good enough as SK beams were not co-aligned. Photo attached.
On SQZT7 we used ZM4 to align to first iris and ZM5 to align to second iris, now H1:SQZ-OPO_IR_PD_DC_POWERMON increased to 0.96mW, still now 1.3mW we're expecting. Opened Beam divertor, TJ then checked that the SQZ beam was making it to SRM and back through the OFI! We can even see SQZ light on AS_C, plot attached. Not easy to take a photo of the beam on the KTP yet.
The SQZ alignment we liked is attached, sdf'ed and was what we had at 2024/07/19 23:00UTC.
Next week, we can decide to keep this alignment or improve the SK co- alignment and realign ZM4,5 path. We should then take our set of power measurements through the OFI/SRM.
This morning I took a dew point measurement of the corner station purge air at the purge valve for the output mode cleaner tube, the following chambers were using the purge air, HAM5 with two soft covers on, and HAM6 with one soft cover. HAM7 was not drawing any purge air.
Dew point measurement is -41.5 oC.
And attached is the end of the day measurement. Dew point of -43.2 oC.
I ran the DARM offset step code starting at:
2024 Jun 13 16:13:20 UTC (GPS 1402330418)
Before recording this time stamp it records the PCAL current line settings and makes sure notches for 2 PCAL frequencies are set in the DARM2 filter bank.
It then puts all the PCAL power into these lines at 410.3 and 255Hz (giving them both a height of 4000 counts), and measures the current DARM offset value.
It then steps the DARM offset and waits for 120s each time.
The script stopped at 2024 Jun 13 16:27:48 UTC (GPS 1402331286).
In the analysis the PCAL lines can be used to calculate how the optical gain changes at each offset.
See the attached traces, where you can see that H1:OMC-READOUT_X0_OFFSET is stepped and the OMC-DCPD_SUM and ASC-AS_C respond to this change.
Watch this space for analysed data.
The script sets all the PCAL settings back to nominal after the test from the record it ook at the start.
The script lives here:
/ligo/gitcommon/labutils/darm_offset_step/auto_darm_offset_step.py
The data lives here:
/ligo/gitcommon/labutils/darm_offset_step/data/darm_offset_steps_2024_Jun_13_16_13_20_UTC.txt
See the results in the attached pdf also found at
/ligo/gitcommon/labutils/darm_offset_step/figures/plot_darm_optical_gain_vs_dcpd_sum/all_plots_plot_darm_optical_gain_vs_dcpd_sum_1402330422_380kW__Post_OFI_burn_and_pressure_spikes.pdf
The contrast defect is 0.889 ± 0.019 mW and the true DASRM offset 0 is 0.30 counts.
I plotted the power at the antisymmetric port as in this entry to find out the loss term between the input to HAM6 and the DCPDs, which in this case is (1/1.652) = 0.605 with 580.3 mW of light at the AS port insensitive to DARM length changes.
From Jennie's measurement of 0.88 mW contrast defect, and dcpd_sum of 40mA/resp = 46.6mW, this implies an upper bound on the homodyne readout angle of 8 degrees.
This readout angle can be useful for the noise budget (ifo.Optics.Quadrature.dc=(-8+90)*np.pi/180) and analyzing sqz datasets e.g. May 2024, lho:77710.
Table of readout angles "recently":
|
|
|
alog | ||
| O4a | Aug 2023 | 46.6 mW | 1.63 mW | 10.7 deg | lho71913 |
| ER16 | 9 March 2024 | 46.6 mW | 2.1 mW | 12.2 deg | lho76231 |
| ER16 | 16 March 2024 | 46.6 mW | 1.15 mW | 9.0 deg | lho77176 |
| O4b | June 2024 | 46.6 mW | 0.88 mW | 8.0 deg | lho78413 |
| O4b | July 2024 | 46.6 mW | 1.0 mW | 8.4 deg | lho79045 |
##### quick python terminal script to calculate #########
# craig lho:65000
contrast_defect = 0.88 # mW # measured on 2024 June 14, lho78413, 0.88 ± 0.019 mW
total_dcpd_light = 46.6 # mW # from dcpd_sum = 40mA/(0.8582 A/W) = 46.6 mW
import numpy as np
darm_offset_power = total_dcpd_light - contrast_defect
homodyne_angle_rad = np.arctan2(np.sqrt(contrast_defect), np.sqrt(darm_offset_power))
homodyne_angle_deg = homodyne_angle_rad*180/np.pi # degrees
print(f"homodyne_angle = {homodyne_angle_deg:0.5f} deg\n")
##### To convert between dcpd amps and watts if needed #########
# using the photodetector responsivity (like R = 0.8582 A/W for 1064nm)
from scipy import constants as scc
responsivity = scc.e * (1064e-9) / (scc.c * scc.h)
total_dcpd_light = 40/responsivity # so dcpd_sum 40mA is 46.6mW
The Phones are back to working again