Monday, December 14, 2020, 11:30

Switched off all breakers in HV cage. Started HV testing of TM3 prototype.

Monday, December 14, 2020, 12:58

Possible first spark at 18 kV.

Monday, December 14, 2020, 14:51

Nothing interesting since then, up to 33.5 kV now.

Monday, December 14, 2020, 14:56

Possible spark at 34.5 kV. 35.5 kV, 36.5, 37.5, 38.5, 39, 39.5, 40.5, 41, 41.5, 42.5, 43 (bigger current spike), 43.5, 44 (vacuum jumped for a bit), 44.5, 45 (voltage drop and vacuum jump).

Monday, December 14, 2020, 16:14

Holding at 45 kV for 10 minutes. Each of these previous "sparks" occurred just after raising voltage. Will decrease step size to 250 V from 500 V if these get more significant.

Monday, December 14, 2020, 16:19

45.5 kV. Went to observe possible spark while Carla raised voltage. Saw small flash towards bottom left, unsure of depth, but perhaps farther to the back.

46 kV. Sparking maybe in the same location. Carla reduced voltage.

Monday, December 14, 2020, 16:47

47 kV. Sort of unstable every time voltage is raised. Decreasing step size to 250 V.

Monday, December 14, 2020, 17:11

48.75 kV. Decreased current limit to 0.005 mA a couple steps previously to see effects. Seems like the current bumps at the start of each voltage raise have dropped from 0.010 mA to 0.005 mA. This seems to indicate that the current limiting is working and is controlled by EPICS. Pierre thinks the prototype must be pretty clean since the testing has been pretty smooth up to this point.

Monday, December 14, 2020, 17:29

49.75 kV. Heard what sounded like an air piston in the background and also saw a large drop in voltage. Voltage dropped in a similar manner a couple minutes after but without the sound. No effect on the vacuum though.

Monday, December 14, 2020, 17:45

50 kV. Held for 8 minutes and then a sound again occurred that sounded like some sort of pneumatic system; along with this a total drop in voltage, but no change in vacuum Otherwise completely stable. Will hold for another 10 minutes or so and ramp down.

Monday, December 14, 2020, 17:53

50 kV. Stable. Starting ramp down.

Monday, December 14, 2020, 18:11

Voltage ramped down. Vacuum has been at around 1.13e-6 Torr throughout this. Shut off power supply. Dumped data to TM3HVtest-20201214-Prototype_2, and earlier I dumped to TM3HVtest-20201214-Prototype. GoPro is taped to vacuum box window.