Today the voltage was raised from 65kV to 65.7kV. After about 10min at this level TM3 started current limiting. TM3 was not sparking when this happened.

ISAC OPS turned it OFF and then tried to ramp it back ON, but could not do it due to the current limiting.

I turned OFF/ON the PS (locally) 20ming ago and and then tried to get it back from the Control Room, but around 4-5kV it started current limiting.

Turned everything OFF on EPICS for the time being. We'll investigate on Monday.

Over the night the sparking rate at 65kV was from 6 to 2 sparks per hour. It tripped OFF once over the night: backing valves closed, tripping the turbos, tripping IG1 and turning OFF the BIAS. At that time ISAC OPS got it back smoothly.