Reports until 09:27, Thursday 03 July 2025
H1 SUS (OpsInfo)
elenna.capote@LIGO.ORG - posted 09:27, Thursday 03 July 2025 - last comment - 14:41, Thursday 03 July 2025(85526)
ETMY violin mode 20 ringing up, flipped gain sign

Sheila, Matt, Elenna

In the midst of trying to diagnose various PI issues, we noticed DCPD sum was slowly increasing, but not from PIs. We eventually figured out it was ETMY violin mode 20. The gain was set to -1. I flipped it to +1 and then mode started being damped down.

Comments related to this report
elenna.capote@LIGO.ORG - 14:41, Thursday 03 July 2025 (85538)

Sheila updated the ETMY ring heater again to 1.5 W, and it looks like ETMY mode 20 phase has flipped back, and a damping gain of -1 is working once again.

It appears that gains of both -1 and +1 are not damping the mode now. Corey is trying different phase filters.