Reports until 09:03, Thursday 13 March 2025
H1 General (CAL)
thomas.shaffer@LIGO.ORG - posted 09:03, Thursday 13 March 2025 - last comment - 10:54, Thursday 13 March 2025(83351)
Lock loss 1530UTC

1425916765

This happened at the end of the calibration measurement. This also happened last week (alog83210).

Comments related to this report
ryan.crouch@LIGO.ORG - 09:49, Thursday 13 March 2025 (83352)CAL

The last 3 calibration measurements have ended in locklosses, todays, saturdays and last thursdays (these link to the lockloss tool webpages). The 3 locklosses look fairly similiar but looking at the ETMX signals, todays seemed a little stronger of a lockloss? Compared to Saturday and last thursday.

Last thursdays lockloss alog83239

Images attached to this comment
camilla.compton@LIGO.ORG - 10:54, Thursday 13 March 2025 (83354)CAL, SUS

Looking at the same channels that Vlad did in 82878 and Ryan's above ETMX channels, the 42Hz growing wobble in DARM/ETMX seems to start as soon as the DAM1_EXC is ramped on to it's full amplitude, plot attached. The 42Hz is seen as an excitation into  H1:SUS-ETMX_L2_CAL_EXC_OUT_DQ, plot attached. Maybe the ETM is not fully stable at that frequency?

Looking at a successful calibration sweep Feb 22nd 82973, There was no instability when the 42Hz oscillation was turned onto ETMX L2, plot attached.

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