'OpsInfo' and 'Lockloss' tags have been added to the LHO and LLO aLOGs. CDS Bugzilla 941 for reference.
Activity Log: All Times in UTC (PT) 07:00 (00:00) Take over from TJ 07:46 (00:46) ETM-Y saturation 08:24 (01:24) ETM-Y saturation 09:22 (02:22) ETM-Y saturation 09:33 (02:33) Reset timing error on ETM-X 09:53 (02:53) ETM-Y saturation 10:42 (03:42) ETM-Y saturation 12:19 (05:19) ETM-Y saturation 12:39 (05:39) ETM-Y saturation 13:05 (06:05) LLO – Going down for maintenance 13:33 (06:33) Power Hit – Short duration power loss 14:15 (07:15) Richard – Going to End-Y to check end station and reset ESD high voltage 14:26 (07:26) Fire Systems Maintenance on site to test hydrants 14:30 (07:30) S&K Electrical on site 14:48 (07:48) Richard – Back from End-Y 14:50 (07:50) Richard – Going to End-X to check end station and reset EDS high voltage 14:55 (07:55) Ken – Going to End-Y to pull cables from End Station to Ion Pump 14:57 (07:57) Karen & Christina – Cleaning in the LVEA 15:00 (08:00) Turn over to Travis End of Shift Summary: Title: 10/20/2015, Owl Shift 07:00 – 15:00 (00:00 – 08:00) All times in UTC (PT) Support: Richard, Peter Incoming Operator: Travis, Shift Summary: 13:33 (06:33) – Lost power to site for a couple of seconds, but long enough to shut down most systyems. Starting site recovery. Peter working PSL recovery. Richard working on site recovery.
The power went out this morning. I went to restart the laser. Pretty much all the alarms on the status screen were set. TwinSafe reported that it was okay. The interlock box status LED did not light up in either the on or off position. I reset all the serial ports on the Beckhoff computer and things came good again. The regular startup was invoked. Laser came up. I engaged the output of the high voltage power supply. None of the servos were locked by the time I got back to the Control Room, as this requires a front end model restart.
A 0634 this morning the Bonneville Power Administration had power dip. Not sure what was happening yet, but this caused a site wide 1 second outage at LHO. We are in the process of restoring systems.
at 13:33 (06:33) lost power to the site for a couple of seconds. Working on recovering the site.
Other than a few ETM-Y saturation's the first half of the shift has been quiet. IFO has been locked in Observing mode for past 13 hours. Range is 75Mpc.
Environmental conditions have deteriorated somewhat over the past 4 hours. The wind is still light (3-7mph) to gentle (7-12mph) breeze, with some gusts up near 20mph. Microseism is elevated but flat over the past 12 hours. The was a 5.4 mag EQ in Chile (R-Wave arrival ~ 10:53 (03:53)).
Reset timing error on H1SUSETMX at 09:33 (02:33).
Title: 10/20/2015, Owl Shift 07:00 – 15:00 (00:00 – 08:00) All times in UTC (PT) State of H1: At 00:00 (00:00) Locked at NOMINAL_LOW_NOISE, 22.5W, 78Mpc. Outgoing Operator: TJ Quick Summary: Wind is a light to gentle breeze; microseism is slightly elevated. IFO in Observing mode. All appears to be normal.
TITLE: 10/19 [Eve Shift]: 23:00-7:00 UTC (16:00-0:00 PDT), all times posted in UTC
STATE Of H1: Locked. Observing @ ~76 MPc.
SHIFT SUMMARY: Locked and Observing my whole shift, a few saturations here or there, environment calm. I still haven't gotten the chance to reset the ADC error, I'll pass that on to Jeff.
INCOMING OPERATOR: Jeff B.
Log:
I will clear this when we are not in Observing, as we currently are and with double coincidence.
Kyle, Gerardo Today we applied Ultratape against the spool and both sides of the stiffener around the entire periphery, in effect, bagging the inaccessible space between the stiffener ring and the spool. Next, we made a small incision and inserted a 1/4" poly tube to allow us to pump the inside of this "tape bag". The overall seal wasn't very effective due to the lack of access in the area of interest - between the spool and the support gusset which is also the area of the leak - but we were able to achieve < 300 torr inside the tape bag. As expected, the Y-mid pressure responded accordingly. So, at this point we have the leak location narrowed down to approx. 1" x 3" at the overlap of the spool seam weld and stiffener stitch weld (poor fabrication technique!) We have some ideas of how to better access this area which we will need to do before applying epoxy or equivalent to seal the leak.
Photos of test setup.
Outstanding detective work! Well done guys. And thank heaven it weren't a gate valve... PS I think we should at least consider running a fusion bead from the inside instead of goop. Section can be vented, right?
Very good that the leak was found. Suggest that the test for ferritic steel be applied to the region around the leak. The test rig for ferritic steel is currently at LLO. It was last used by Tomeka Lewis and Harry Overmier. Useful to know if we are in trouble all around or this location was an anomoly.
Laser Status:
SysStat is good
Front End power is 32.13W (should be around 30 W)
Frontend Watch is GREEN
HPO Watch is RED
PMC:
It has been locked 11.0 days, 20.0 hr 27.0 minutes (should be days/weeks)
Reflected power is 1.917Watts and PowerSum = 25.65Watts.
FSS:
It has been locked for 0.0 days 3.0 h and 30.0 min (should be days/weeks)
TPD[V] = 1.512V (min 0.9V)
ISS:
The diffracted power is around 9.125% (should be 5-9%)
Last saturation event was 0.0 days 3.0 hours and 30.0 minutes ago (should be days/weeks)
Things to note:
The usual LRA out of range andVB program online warngins are red on SYSSTAT.adl
O1 days 29, 30, 31
model restarts logged for Sun 18/Oct/2015 No restarts reported
model restarts logged for Sat 17/Oct/2015 No restarts reported
model restarts logged for Fri 16/Oct/2015 No restarts reported
TITLE: 10/19 [DAY Shift]: 15:00-23:00 UTC (08:00-16:00 PDT), all times posted in UTC STATE Of H1: Locked. Observing @ ~76 MPc. SHIFT SUMMARY: Recovered easily from single lock loss. No apparent corresponding seismic cause. Evan and Sheila took time after recovery to work on measurements at ISCT6. Kyle and Gerardo working on leak checking at mid Y. Joe and Chris working on sealing concrete enclosure over X arm. Kiwamu fixed SDF value for H1:PSL-ISS_SECONDLOOP_SIGNAL. INCOMING OPERATOR: TJ ACTIVITY LOG: 15:02 UTC Jeff B. checking TCS chillers in mechanical building 15:16 UTC Jeff B. back 15:20 UTC Crew heading out to work on X arm concrete enclosure approximately four doors past mid X. 17:10 - 17:17 UTC Stepped out of control room ~18:39 UTC Corey in control room giving tour to two people 19:28 - 19:48 UTC Stepped out of control room 20:11 UTC Kyle getting part out of LVEA 20:21 UTC Kyle back, reports light is on in room immediately after card reader 20:25 Evan and Sheila moving computer from PSL racks to ISTC 6 20:33 UTC Joe driving up X arm to work on beam tube sealing 20:54 UTC Betsy to LVEA to turn on CDS wifi for Evan and Sheila 20:55 UTC Kyle and Gerardo to mid Y for leak checking 21:11 UTC Betsy to LVEA to check on wifi/issue logging into computer 21:18 UTC Betsy back 21:29 UTC Evan and Sheila done ~21:52 UTC Kyle and Gerardo back 22:02 UTC Kyle and Gerardo heading back to mid Y 22:15 UTC Joe back from beam tube enclosure, Chris still there. 22:31 UTC John to mid Y to join Kyle and Gerardo
Attached is the whiteboard plan for tomorrow's Tuesday Maintenance period. Basically, we'll drop the lock first thing in order to misalign ETMs for an SRY characterization study, then roll through some ISS 2nd loop characterization. As shown on the whiteboard, people needing to go to the end stations should do so which the SRY study is going such that End station charge measurements can go on unadultured. After all of this, relocking will resume and commissioners will spend some time on jitter and upconversion studies. See picture for additional scheduled tasks.
Darkhan, Sudarshan, GregM, RickS
The plots in the first attached multi-page .pdf file use SLMtool data (60-sec. long FFTs) taken during the month of Oct. so far.
The first page shows the time-varying calibration factors.
The next eight pages have two plots for each of the four Pcal calibration lines (36.7 Hz, 331.9 Hz, 1083.7 Hz, and 3001.3 Hz).
The first of each set shows the calibrated magnitudes and phases of the strain at each frequency (meters_peak/meter).
The second plot in each set shows ratios (mag and phase) of the three methods (Cal/Pcal, GDS/Pcal, and Cal/GDS). The center panels (GDS/Pcal) are most relevant because we expect discrepancies arising from the CAL_DeltaL_External calculations not including all the necessary corrections.
The plots in the second multi-page .pdf file show the GDS/Pcal ratios at the four Pcal line frequencies over the time period from Oct. 7 to Oct. 11, with histograms and calculated means and standard errors (estimated as standard deviation of the data divided by the square root of the number of points).
Note that these time-varying factors (kappa_tst and kappa_C) have NOT been applied to the GDS calibrations yet, so we expect the GDS/Pcal comparisons to improve once they are applied.
The difference of ~9% in 3 kHz line (mean value) probably comes from the foton IIR filtering which is ~10% at 3 kHz i.e., the front-end DARM is 10% higher than the actual value. SInce online GDS (C00) is derived from output of front-end model, it would also show similar difference. However the offline GDS (C01 or C02) corrects for this and hence expect not to show this difference.
As part of Wednesday's commissioning excercises, we looked at the coupling of input jitter into DARM.
I injected band-limited white noise into IM3 pitch (and then IM3 yaw) until I saw a rise in the noise floor of DARM.
We can use the IM4 QPD as an estimate of the amount of jitter on the interferometer's S port. On the AS port side, we can use the OMC QPDs as an estimate of the AS port jitter, and DCPD sum indicates the amount of S port jitter coupling into DARM.
One thing of note is that the jitter coupling from IM3 to DARM is mostly linear, and more or less flat from 30 to 200 Hz:
The upper limit on IM3 jitter that one can place using the IM4 QPD seems to be weak. At 40 Hz, projecting the quiescent level of the IM4 yaw signal to the DCPD sum suggests a jitter noise of 2×10−7 mA/rtHz, but this is obviously not supported by the (essentially zero) coherence between IM4 yaw and DCPD sum during low-noise lock. Of course, this does not rule out a nonlinear coupling.
As for AS port jitter, the coupling is seen more strongly in OMC QPD B than OMC QPD A.
The test excitation for yaw was 6 ct/Hz1/2 at 100 Hz.
We can propagate this to suspension angle as follows:
This gives 73 prad/Hz1/2 of yaw excitation at 100 Hz, which implies a DCPD coupling of 550 RIN/rad at 100 Hz.
Repeating the same computation for pitch [where the excitation was about 10 ct/Hz1/2 at 100 Hz, and the compliance at 100 Hz is 0.012 rad/(N m)] gives a pitch excitation of 140 prad/Hz1/2, which implies a DCPD coupling of 130 RIN/rad at 100 Hz. So the IM3 yaw coupling into DARM is a factor of 4 or so higher than the IM3 pitch coupling.
These excitations amount to >100 µV/Hz1/2 out of the DAC. Unless the IMs' electronics chains have an outrageous amount of input-referred noise, it seems unlikely that electronics-induced IM jitter is anywhere close to the DARM noise floor. Additionally, the seismically-induced motion of IM3 must be very low: projections of the HAM2 table motion suggest an IM3 suspension point motion of 10 prad/Hz1/2, and this motion will be filtered by the mechanical response of the suspensions before reaching the optics.
... and added OpsInfo task to H1 and LHO sections.