Jennie W, Elenna C, Keita K, Ryan S, Daniel S,

This morning JAC lost lock and couldn't re-lock. We solved this by clearing history in the JAC ASC and using the sliders to bring back JM1 osem values to those they had before the lock loss. NB: The process should be to clear history in the four ASC filter banks and in the JM1 suspension LOCK filter banks.

Zooming in on the time when we lost lock it looks like it was mainly DOF1 Y (yaw of PSL PZT) that got pulled away by the ASC as the JAC transmitted power dropped because the PZT ran out of range at the lower end. See zoomed in image here.

Because DOF1 now had a large output signal this then meant that the wavefront sensors were not centred in yaw and so prevented us re-locking as the alignment was so bad.

Here is the long term trends showing when we lost lock, when we cleared history, and when we re-locked.

A better temperature servo should help this.