ibrahim.abouelfettouh@LIGO.ORG - posted 08:57, Thursday 19 June 2025 - last comment - 19:21, Thursday 19 June 2025(85178)
Locklosss 15:55 UTC
Lockloss whilst running simulines. Since this has happened in the last two weeks, caused by the sweep, and there are no immediate other causes, it is probably what caused the Lockloss. We were in Observing for nearly10 hrs.
I wasn't able to confirm for sure that the lockloss was caused by the calibration sweep. It looks like the QUAD channels all had an excursion at the same time, before the lockloss was seen in DARM(ndscope1). It does look like in the seconds before the lockloss, there were two excitations that were ramping up (H1:SUS-ETMX_L2_CAL_EXC_OUT_DQ at ~6 Hz(ndscope2) and H1:SUS-ETMX_L3_CAL_EXC_OUT_DQ at ~10Hz(ndscope3)). Their ramping up is not seen in the QUAD MASTER_OUT channels, however, so it's hard to know if those excitations were the cause.