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Message ID: 1959     Entry time: Thursday, August 08, 2019, 09:33
Author: Carla Babcock 
Category: ITE 
Type: Development 
Module: TM2 
Target/Number: Ta#58 
Subject: TM2 HV conditioning with protons, round 1 

Starting HV tests on TM2 with 50uA of protons.

Tuesday, August 06, 2019, 03:37 : Ramping up 500V every 2mins or so, couple of sparks, then consistent sparks at 34kV. No vacuum response on IG1 for any sparks, even though the current spikes from around 40uA to 1300uA. Brought it down to 28kV to stop sparking. See a response on the EZL frequently.

Tuesday, August 06, 2019, 05:24 : Going above 30kV proves very difficult, lots of up and down, frequent sparks, still no vacuum response. Still seeing an EZL response.

Tuesday, August 06, 2019, 05:58 : Up to 31.5kV on bias, 1046V on EE and 15kV on EZL.

Tuesday, August 06, 2019, 06:50 : Controls are being sticky - not responding well.

Tuesday, August 06, 2019, 07:25 : Sat at 32 kV > 20mins with 2 sparks

Tuesday, August 06, 2019, 08:03 : lots of sparking at 36kV, went back down to 35kV. Current draw is 50uA.

Tuesday, August 06, 2019, 08:10 : lots of sparking after 9 mins at 35kV, had to turn it down to 34kV

Tuesday, August 06, 2019, 08:11 : Still sparking at 34, down to 33

Tuesday, August 06, 2019, 08:31 : At 33kV, sparked twice in 20mins and was going for another when the protons went off.

With protons off, the bias current dropped quickly from 66uA to 40uA and raising the bias to 40kV was not difficult.  Later bias up to 50kV. Still no conclusion on if the sparking was inside or outside of the vacuum. No vacuum response seems to indicate outside, however the influence of protons would indicate inside. To be investigated visually when TM2 comes to the HC.

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