While the ITF was locked in DC readout this afternoon, we enabled the computation of the B1 DARM dither signal and engaged the B1 DARM beam drift control of SDB1 (Fig.1). This has the effect of increasing the optical gain by almost a factor 2, while the bench alignment changed by almost 10 urad in TX and by 1 or 2 urad in TY.

Accordingly after the unlock, the B5 QD2 offsets were updated (H=+40 and V=+200).