Monday, June 10, 2019, 16:59 : TM4 back up to BIAS / EL = 56.1kV / 29.5kV

Monday, June 10, 2019, 17:14 : After 57kV on the bias, things seem to be getting sketchy. The EL voltage and current are a bit jumpy and stepping that voltage up seems to produce a slight spike in the bias current.

Monday, June 10, 2019, 17:31 : At BIAS / EL = 58 / 30.3, looks ok.

Monday, June 10, 2019, 18:11 : Sitting at 59.5kV, could probably push further but will sit here for ~30mins and make sure it is relatively stable. Note 59.5kV set point is really 56.9kV on readout.

Monday, June 10, 2019, 18:18 : some current inconsistencies (not really sparks probably corona discharges...) so went down to 59kV

Monday, June 10, 2019, 18:23 : still getting some sparks at 58kV, going down to 57.5.

Monday, June 10, 2019, 18:37 : went back up to 58, spent 10 mins there but was getting these corona-discharge-type-sparks where the vacuum responds and current is drawn but voltage is maintained. Went down to 57kV, still getting them....

Monday, June 10, 2019, 18:40 : Going down to 56 to see if they stop....

Monday, June 10, 2019, 18:42 : Trying 55 kV now... see attached screenshot for example of sparks

Monday, June 10, 2019, 18:48 : No luck at 55 or 54kV. Going down to BIAS / EL = 50 / 27 for a while to see if this resolves

Monday, June 10, 2019, 19:20 : 30 mins at 50kV, a couple little sparks, but no big deal. Ramping up to 55 and let's see if it is ok.

Monday, June 10, 2019, 19:30 : 55 still not working, going down to 54

Monday, June 10, 2019, 20:16 : Held bias at 54kV for about an hour - dropped it down once to alleviate some sparking. Leaving it at 50kV overnight, ops have instructions to keep an eye on it and shut it off if anything seems strange.