Apparently wind is still an issue. After a brief lull, sustained winds are back above 40 mph.
No issues coming back up. Winds are still 30+ mph with a few 50 mph gusts, but we managed to get back to NLN. PI mode 23 has been giving a bunch of alarms since the winds started, but they quickly ring back down (on the order of seconds). Also have received a few Tidal X and Y error messages, but they don't seem to be affecting locking.
Lockloss likely due to high winds, which were gusting to 50 mph at the time of the lockloss.
Locked in Observing for 11.5 hours. Wind has picked up significantly since the beginning of the shift (now approaching 40mph) and the range has started to suffer as a result (~50 MPc). No issues otherwise.
Another GRB alert at 15:30 UTC.
TITLE: 03/18 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 67Mpc
OUTGOING OPERATOR: Ed
CURRENT ENVIRONMENT:
Wind: 10mph Gusts, 9mph 5min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.25 μm/s
QUICK SUMMARY: No issues handed off. Observing for the past 7 hours.
TITLE: 03/18 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Observing at 68Mpc
INCOMING OPERATOR: Travis
SHIFT SUMMARY:
LOG:
12:12UTC GRB alert. Livingston contacted for confirmation of alert. Both IFOs observing.
7:20 Lockloss - ?
7:57 NLN
7:59 Checked a2l measurement - looked fine
8:00 accepted damping diffs for ITMY and ETMX as per the whiteboard notes
8:01 Intention Bit: Undisturbed 71Mpc
No alignments necessary. Had to spend time at Locking ALS to avoid repeated locklosses at FIND_IR. No further issues.
TITLE: 03/18 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Observing at 69Mpc
OUTGOING OPERATOR: Patrick
CURRENT ENVIRONMENT:
Wind: 4mph Gusts, 3mph 5min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.26 μm/s
QUICK SUMMARY:
No news is good news
Spoke too soon.....
TITLE: 03/17 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC STATE of H1: Observing at 69Mpc INCOMING OPERATOR: Ed SHIFT SUMMARY: In observing the entire shift. No issues or changes in status to report. Note Cheryl's alog about SDF changes for bounce mode damping if we lose lock. LOG: ~03:39 UTC Unidentified noise in control room. Sounded vibrational. Lasted for about a minute. HVAC?
No change in status or issues to report.
I analyzed the HWS data for the lock-acquisition that occurs around 1173641000. The "point source" lens appears very quickly (within the first 60s) and then we see a larger thermal blooming over the next few hundred seconds. I've plotted the data below (both gradient field and wavefront OPD). There are a few obviously errant spots in the HWS gradient field data. Since I'm still getting used to Python, I've not managed to successfully strip these off yet. However, it is safe to ignore them.
Check out the video too. Next step is to match a COMSOL model of thermal lensing with a point absorber to the data to get a best estimate of the size of absorber and the power absorbed (preliminary estimates are of the order of 10mW).
FYI: this measurement compares the system before, during and after a lock-acquisition (ignore the title that says "lock-loss"). The previous measurement, 34853, looked at lens decay before, during and after a lock-loss.
For your amusement I've attached a GIF file of the same data. My start time is 79 seconds prior to Aidan's "current time".
The integrated gradient field data for H1ITMX is contained in the attached MAT file. It shows the accumulated optical path distortion (OPD) after 2.75 hours following the lock acquisition around 1173640800. This is the total accumulated OPD for a round trip through the CP+ITMX substrates, reflection off ITMX_HR and back through ITMX+CP substrates.
Note: this image is inverted. In this coordinate system, the top of the ITM is at the bottom of the image.
Here is the wavefront data with the superimposed gradient field. The little feature around [+30mm, +20mm] does not appear in the animation of the wavefront or gradient field over much of the preceeding 2.75 hours. My suspicion is that this is a data point with a larger variance that the other HWS data points, rather than a true represtation of wavefront distortion.
I fitted, by eye, a COMSOL model of an absorber (14mm diameter Gaussian, ~25mW absorbed) to the measured HWS data. I then removed this modeled optical path distortion to get the following residual (lower left plot). I then fitted a COMOSL model of 30mW uniform absorption to this model and subtracted it to get the residual in the lower right plot.
Here's the total fitted distortion from the sum of two COMSOL models (point absorber + uniform absorption):
TITLE: 03/17 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 69Mpc
OUTGOING OPERATOR: Cheryl
CURRENT ENVIRONMENT:
Wind: 6mph Gusts, 4mph 5min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.18 μm/s
QUICK SUMMARY:
No issues to report.
| ETMX | 9.776 Hz |
| ITMY | 9.831 Hz |
Under such high sustained wind speeds (>40 mph), I would recommend switching the beam-direction rotation loops on Stage 1 ISIs to 90 mHz blends instead of the 250 mHz blends. This is not automated, I think, so you may have to do it by hand for each chamber: rX on ETMY, ITMY and rY on ETMX and ITMX. Jim and Rich had showed that this was helpful under high winds.
I texted Jim for some more advice related to Krishna's suggestion. He informed me that he is on his way to the site. I will wait for him to arrive before making any changes to the SEI configuration. Stay tuned.