At the beginning of the shift we unlocked the ITF in order to re-acquire LN2.

Before re-locking, we added in DRMI_LOCK.py, DOWN state, the instructions to set to 0 the new elements of BS_TX/Y sensing matrix relative to B1s quadrants and reloaded the metatron node.

At 16:51:00 UTC the ITF unlocked due to glitches on B7(Fig.1). They are perfectly timed with errors on SNEB_Fb (16:50:35 and 16:51:03). This happened again at 17:09:40.

We alerted Alain Masserot and he solved the issue.

After we reached LN2, we turned on the line at 3.1 Hz on BS_TX and attempted to measure the TF between BS_TX and B1s_QD1_Y. After measuring the coefficient we attempted the hand-off, but B1p drifted away as a result.

During the re-lock we examined the transfer function with longer time windows, to get a more accurate measurement (fig.2). At 3.1 Hz, with good coherence, the ratio between the two channels is +0.32, which gives a weight for B1s_QD1 equal to +3.12. The first measurement gave a coefficient with the wrong sign, which explains the drift of B1p.

There was no time to try again, we leave the ITF locking up to LN3_SQZ.