This morning we checked the locking point and the offset on the QPD centering of the IMC cavity. 

We first realized a scan of the locking point and find that, after the work on PSL/INJ of the last days, it changed by almost 2V (from -1.2V to +0.72).

Moreover, since yesterday night we got unlock due to SSFS oscillation at around 6Hz, we studied the coupling between the SSFS and the INJ AA loop by performing the scan of the offset on the INJ_AA  QPD (the same as sunday).

We found that in particular one of the offset on a QPD increased again. 

The new measurements are:

FF H 1362050516 : optimal wp is -0.48

FF V 1362050783 : optimal wp is -0.095 (see fig. 1 as exemple)

NF H 1362048400 : optimal wp is 0

NF V 1362048400 : optima wp is -0.065

these have been updated in ISYS_Acl. Apparently, this solved again the issue of SSFS/IB.

We will check next days the evolution of both.