ryan.short@LIGO.ORG - posted 16:53, Tuesday 29 August 2023 - last comment - 17:11, Tuesday 29 August 2023(72533)
Lockloss @ 23:50 UTC
Lockloss @ 23:50 UTC - no immediate obvious cause.
H1 had relocked to NLN by 23:18 UTC after SQZ team ran their checks, but the range was significantly lower (~120Mpc), so investigations were ongoing into the loss of sensitivity. H1 was not observing between reaching NLN and this lockloss.
Winds have picked up this afternoon, now over 30mph, although unsure if this would be the cause of the lockloss. It will make relocking challenging, however.
The hourly forecast (link) suggests we should have similar / worse than right now wind for the next several hours, and then the wind will start to calm down (a bit, not a lot) around 8pm or 9pm. I've suggested to RyanS that if the IFO doesn't lock in the next few tries, that he leave the IFO in DOWN for 2-3 hours until the wind starts to come down.
Separately, we had a surprising amount of trouble locking this afternoon, but much of that time was before the wind picked up. We don't really know why we were able to successfully lock the one time we did. I'm hopeful that once the wind calms down, locking will be straightforeward, but it may not be.