J. Kissel

In the rush and panic of ER9 last week, we neglected to aLOG that we reverted the ETM ESD bias flip that I'd done last Tuesday because -- for some unknown reason -- the sign flip *this* time caused problems for ALS DIFF and subsequently switching to EY later in the acquisition sequence. As such, we didn't gain as much in this week's charge mitigation, as shown by the plots attached below, which includes a new measurement from today. The effective bias voltage is still within the ~10 [V] range, so the reversion did little harm.

Since ER9, we haven't had the time to explore why the flipping failed us. I'll continue to try to push for figuring this out, but we'll see what kind of priority it gets with respect to all other commissioning tasks.