[Jenne, Stefan, Georgia, Matt, Elenna, Ryan S]
We have made it almost through the "Max Power" state of the guardian! During the last power up step from 55 to 60W we had a fast lockloss. It appears to be about 16 Hz and in the DARM loop itself. Since we are down and reset the green references, we are running an initial alignment. Once that completes, we will try locking again, possibly with a slow power up by hand and measurements of the DARM loop gain. The violins are a bit high but Ryan engaged the 2W damping settings and they were coming down well.
We reran initial alignment with the new green references. We used the guardian to lock the interferometer without human intervention. Except Gabriele touched the PRM alignment while DRMI was locked to improve the POP18 buildup. We realized that while we were powering up to 25W the spot on the OMC trans camera was drifting in yaw. The OMC suspension started to saturate. At 25W we switched DARM back to RF by reverting the LSC input matrix by setting the OMC to DARM input matrix element to zero. The AS_A_RF45Q to -1E-6. We took the OMC guardian to down and gracefully cleared the history of the OMC SUS. We're not sure why the OMC_ASC failed. Gabriele and Camilla are looking into it. The error signal seems to have frozen between CHECK_VIOLINS_BEFORE_POWERUP and POWER_10W.
We are leaving the interferometer down.
More trends of OMC alignment signals
It looks to me like the OMC QPD were saturating