Started with Anode at 25V and coil at 0A, bias at 30kV. (attachment 1)
Ramped coil to 60A (0.4V) (attachment 2)
Ramped bias to 51kV, but then TP6 turned off and there was a momentary 0.2A decrease in the TGHT current. No spike in BIAS current seen, maybe TP6 is turning off for another reason? (attachment 3)
At 57kV, a small spark, heard outside the vacuum, sounding like it comes somewhere near the blue racks which hold the power supplies. It has sounded like that to me before. Did not turn anything off but bias current spiked from 110uA to 280uA. (attachment 4)
At 57.5kV another spark, taking down TP1B and TP6, as well as the CB1 steerers and TPS:Q1/2. TGHT current dropped momentarily from 581A to 240A, or so says EPICS. Maybe just a communications effect? Voltage for TBHT also dropped but nothing seen on TBHT. Coil current and voltage also showed small effects. (attachment 5)
After 10mins at 60kV, spike in bias current with slight spike in EE current but no other effects.
After 20mins everything has been stable, will turn the bias back to 30kV. As I turn the bias voltage down, the EE current ramps up. No change to EE voltage... (attachment 6) |