thomas.shaffer@LIGO.ORG - posted 09:48, Wednesday 01 May 2019 - last comment - 17:20, Thursday 02 May 2019(48897)
Briefly out of Observing for small change
LLO informed us that they would be out of observing for ~20 min while they damped violin modes. Virgo was also down, so we got the okay to make a small change.
1639 Out of Observing
1645 Observing
Comments related to this report
jenne.driggers@LIGO.ORG - 11:35, Wednesday 01 May 2019 (48898)
I took this opportunity to change the MICH and SRCL feedforward, with some new fits to the data I took on Friday after we'd thermalized with the SR3 heater at 4W (alog 48792).
Unfortunately, I don't think it's actually better. In the attached figure, blue is a reference from earlier in this lock, and red is after I'd switched both MICH and SRCL feedforward filters to the new fits. The MICH coherence went down, but that could be just because the SRCL made things a bit worse? We lost about 3 Mpc with the new feedforward.
Images attached to this comment
jenne.driggers@LIGO.ORG - 17:20, Thursday 02 May 2019 (48950)
This afternoon, while working on some ASC things, I reverted the SRCL FF to the old nominal Feb28 filter. I don't see a change in the DARM spectrum, but the coherence between DARM and SRCL has decreased. MICH is still using the new fits.
I took this opportunity to change the MICH and SRCL feedforward, with some new fits to the data I took on Friday after we'd thermalized with the SR3 heater at 4W (alog 48792).
Unfortunately, I don't think it's actually better. In the attached figure, blue is a reference from earlier in this lock, and red is after I'd switched both MICH and SRCL feedforward filters to the new fits. The MICH coherence went down, but that could be just because the SRCL made things a bit worse? We lost about 3 Mpc with the new feedforward.
This afternoon, while working on some ASC things, I reverted the SRCL FF to the old nominal Feb28 filter. I don't see a change in the DARM spectrum, but the coherence between DARM and SRCL has decreased. MICH is still using the new fits.