Ramped down the bias so David could remove the HV cover and lock out the target hall.

Ramped back up to BIAS / EL = 50kV / 26kV quickly with no sparks.

Monday, June 10, 2019, 15:35 : BIAS / EL = 52kV / 26kV

Monday, June 10, 2019, 15:45 : BIAS / EL = 54kV / 28.5kV. It seems that keeping the EL at 1/2 the bias voltage is right on the edge of what is acceptable - the HV seems to be sparking to the EL instead of to ground (either that or the EM interference from the sparks it producing a reaction in the EL...) I will run the EL higher and see if that helps.

Monday, June 10, 2019, 15:57 : Sat at 54kV for > 10mins, will continue up

Monday, June 10, 2019, 16:11 : At BIAS / EL = 55.8kV / 29kV got some sparks, some to EL and some to ground. Back at 55kV.

Monday, June 10, 2019, 16:24 : Sitting at 56kV for a couple mins

Monday, June 10, 2019, 16:37 : Sitting at 56.3kV bias, a spark tripped off the IG1S, which tripped the turbo and shut down all the HV. Back to zero!