At first we found a good one for the sidebands, dark fringe and sensitivity (maximum 48 Mpc with no squeezing and without PCal lines) but with a bad CMRF (step in hrec at high frequency clearly visible) (see fig.1) .
This configuration has been achieved with the following TCS DAS parameters:
-WI DAS IN: 88 mW
-WI DAS OUT: 133 mW
-NI DAS IN: 335 mW
-NI DAS OUT: 1.491 W.
The alignement set points were:
BS_TY_SET=0
BS_TX_SET=-0.012
PR_TX= 0.004
PR_TY=-0.004
Diffp_TX=0.005
Diffp_TX=0.017
Then with the same TCS configuration we changed the BS _TY_SET to recover a good CMRF. To do this we set BS_TY_SET=-0.007. The sensitivity curve worsened (SDB1 bumps between 300 and 600 Hz and low frequency) (see fig 2).
Then we started to change the working point of the DAS to improve the sideband and dark fringe in that configuration but without success.
We tried to compensate the misalignment of the BS acting with the DAS, but it doesn't seem to be the right action. Maybe it is better to reach a good working point for the fringe and the sidebands and then try to minimize the CMRF by tuning the TCS powers (common mode).
After these tests the ITF unlocked and then it locked again with not-so-different DAS parameters:
-WI DAS IN: 80 mW
-WI DAS OUT: 80 mW
-NI DAS IN: 460 mW
-NI DAS OUT: 1.473 W.
We achieved again 48 Mpc without squeezing and no Pcal lines (see fig.3).
We left the ITF with the current configuration of TCS and the alignment set points saved in metatron.
I switched back the PCals on around 5h31 UTC.