Input mirrors have been moved in transversal directions (X and Y) in order to zero the alignment error signals from the demodulation of the arm transmitted power at the LF angular dithering lines of the input mirrors. See pic 1.
The movement has been used to calibrate such errors in um. In fact, when centering loop and PR trasverse/BS steering loops are active, these error signals give a measurement of the distance between input beam and input mirror centers.
After the change the ITF has been relocked up to carm null twice. (see pic2)
We didn't observe relevant change in the ITF behaviour during either lock acquisition and at carm null. The presence of occasional jumps was still spoiling the quality of the lock.
During both locks the PR_TY set point adjustment loop was automatically activated. While at the beginning it seems to work fine, it starts showing a strange behaviour after a while (in the case of the second lock the strange behaviour started in the same moment of a jump) (see pic3). The commands to automatically activate the loop are commented in metatron.
We also commented the SR angular loop engagement at carm null as in the past it was observed that the error signal is not reliable at the beginning of the lock.
We switched on CITF and let Ilaria switch PR RH on (fig 4). We left CITF locked for the night with the autorelock engaged.