In order to take the reference before switching on the PR RH, Antonino performed the scan with the green laser from 14:59:10 to 15:08:18 UTC.

Then, we experienced some issues to lock the CITF related to the drift of SDB2 (fixed by Romain). Once the CITF locked, the PR RH has been switched on with the power of 5 W at 16.52 UTC. From the simulations we expect Delta RoC= -3.6 m (RoC=1477 m→ 1473.4 m). Concerning the thermal lensing we expect  2.34e-5 dioptres.

During the thermal transient, the ITF has been kept locked in CITF as already did in yesterday shift for the SR RH test (entry 55826) and, at around 20 UTC, ISC people started to try to lock the ITF at CARM null (see fig.1).

We tuned the phase of the 169MHz, which turned out to be the same as yesterday. We didn't have to tune the gains during the CARM offset reduction by much. We tried to reach CARM offset 0 once but we unlocked. We are unsure of the phase of DIFFp so WE LEFT THE LINES THAT CLOSE DIFFP IN DRIFT CONTROL IN CARM STEP3 COMMENTED for the time being (2322-2323). The recovery will continue tomorrow.

In the end a new scan with the green laser has been performed by Antonino between 21.12 UTC and 21.21 UTC.

We left the cavities locked on the IR and PR RH on.