The system was vented to  make clearance on the waterlines as a very small continuous discharge was observed.

The inspection revealed some marks on the HS water line (sideview photo). From the the bottom and from real close (zoom and backview photo) the marks are quite noticeable with shinny copper in the middle and dark circles around.

The GND line is routed in such a way that sits on top of the ion gauge chamber (gnd-ig1) this could explain why the vacuum had small oscillation during the current limited events.

Moreover, the GND line has the steerer cables tied to it, this could explain why one of the steerers got affected after the sparks.

Also, the GND line is in contact with a dark grime that goes all the way into the first skimmer (gnd-quad). I think the grime observed inside the test stand might have become conductive, or if this is trace from a previous flashover, this  is good path to flash again.

The EE and the plasma electrode were removed and they show signs of buildup. Cleaned and reinstalled

Monday, February 01, 2021, 08:38 : The anode seems to be shorted but we can still test the  amount of dispersion at the image position, and correlate with energy spread.

Monday, February 01, 2021, 11:27: Bias/EZL/EE @ 30/0/1.5 kV. 

 Monday, February 01, 2021, 11:44: Mass scan in progress. The peaks appear to be shifted. Large peak at  m/q160 and double peak at m/q 100u, where I think it should be 133Cs and 85Rb and 87Rb.

Monday, February 01, 2021, 14:04: HV turned itself off, nothing tripped nor change. Not sure if related to the emittance scan that I was running. Setting it to zero before restarting it.

Monday, February 01, 2021, 20:14: Ramping things down and call it a day. My laptop charger broke and I don't want to leave the HV on.

Wire scanners look fine but the emittance meter was not working. Keiko soft reboot it but to luck. 

AS

Tuesday, February 02, 2021, 08:51: E-rig re-calibrated. Mass scans taken. It appears we have evaporated all the salts. Turning off the HV & auto-cooling @ 3A per min.

Tuesday, February 02, 2021, 12:18: IV4 closed, power/sources off. Turbo pumps off.

Tuesday, February 02, 2021, 12:50: Venting.

Remove, add salts, EE ok.

Tuesday, February 02, 2021, 13:58: Rouging.

Tuesday, February 02, 2021, 14:26: Turbo pump on - TP1B.

Tuesday, February 02, 2021, 14:37: Turbo pump on - TP1A. Ion gauge on.

AS

Wednesday, February 03, 2021, 07:36: Vacuum ok @ 1.01e-06 T.

Wednesday, February 03, 2021, 07:38: Opened FS#5. Vacuum ok.

Wednesday, February 03, 2021, 07:41; Power / Sources on. Optics on.

Wednesday, February 03, 2021, 07:43: Auto-ramping TGHT / TBHT to 350 / 150 A @ 4 A per min.

Wednesday, February 03, 2021, 07:46: IV4 open

Wednesday, February 03, 2021, 07:48: BIAS / EE / EZL @ 20 / -1.0 / 0 kV to start. will go to 30 & 1.5 kV once the TGHT reaches 350 A.

Wednesday, February 03, 2021, 09:40: Auto-ramping TGHT / TBHT to 580 / 230 A @ 2 A per min.

Wednesday, February 03, 2021, 10:55: BIAS / EE / EZL @ 30 / -1.5 / 0 kV. Lot's of sparks on the initial conditioning from 8:30am until almost 10:20. Appears stable now.

 FM

Wednesday, February 03, 2021, 13:01: Spark. The HV bias voltage remained at 10 kV for several seconds. TSG:CBC was @ 2500 V. Likely, a sustained discharge towards the steerer had the HV bias power supply to get current limited

 Wednesday, February 03, 2021, 13:25: HV bias power supply gets current limited as of 15 kV. Setpoints to 0 to allow some discharge. Didn't work. Asking someone on site to have a look on the PS.

No sign whatsoever of a spark  to any device.

Wednesday, February 03, 2021, 18:27: HV has been erratic all day. Waiting for some stabilization allowed the system to reach ~24 kV. Now it has dropped to 20 kV.

Wednesday, February 03, 2021, 18:28: Increasing current limit on the bias PS from 0.015 to 0.02 mA

Wednesday, February 03, 2021, 18:55: Spark in the water lines. Current drop 60% from 0.03 to 0.01 uA. Spark observed in the GND electrode water lines

Wednesday, February 03, 2021, 19:11: Able to reach 28 kV but a spark ocurred.  TSG:CBC adn TSG:Q1 readback 2500 and 1500 V (similarly to the spark at 1 pm). Bias is current limited again, even at the new current limit.

• I think there might a short with one of the steerers cables, or a bit unlikely, to the quad.
• Slow charge up process, that does not discharges.

Wednesday, February 03, 2021, 19:32: Bias/EZL/EE @ 0.000 kV

Wednesday, February 03, 2021, 22:59: Tapped down TGHT/TBHT to 500/200 A to preserve the salts.

AS

Thursday, February 04, 2021, 06:42: Auto-cooling TGHT / TBHT down to 300 / 150 A. 

Thursday, February 04, 2021, 09:14: Optics set to standard settings. Checking BIAS w/ EE & EZL 

Thursday, February 04, 2021, 09:21: BIAS / EE / EZL to 16.5 / -1.0 / 10 kV. Actual on BIAS 14.5 to 15 kV on BIAS:RDVOL & w/ 0.029 mA on BIAS:RDCUR.

Thursday, February 04, 2021, 09:24: BIAS discharge. 16.5 kV on BIAS:RDVOL & w/ 0.004 mA on BIAS:RDCUR.

Thursday, February 04, 2021, 09:32: Brought BIAS up to 19 kV, but then it sparks and dropped to 13.5 kV on BIAS:RDVOL & w/ 0.029 mA on BIAS:RDCUR. Brought the BIAS down to 13 kV, & the current dropped out, then stabilized. Brought it back up to 16.5 kV. Holding 16.5 kV on BIAS:RDVOL & w/ 0.004 mA on BIAS:RDCUR.

Thursday, February 04, 2021, 09:36: BIAS / EE / EZL to 16.5 / -1.0 / 10 kV

Thursday, February 04, 2021, 09:39: Auto-cooling TGHT / TBHT down to 0 A. 

Thursday, February 04, 2021, 09:40: 17 kV - BIAS:RDVOL / 0.005 mA - BIAS:RDCUR.

Thursday, February 04, 2021, 09:45: 17.5 kV - BIAS:RDVOL / 0.005 mA - BIAS:RDCUR.

Thursday, February 04, 2021, 09:51: 18 kV - BIAS:RDVOL / 0.005 mA - BIAS:RDCUR.

Thursday, February 04, 2021, 09:55: 18.5 kV - BIAS:RDVOL / 0.005 mA - BIAS:RDCUR.

Thursday, February 04, 2021, 10:00: 19 kV - BIAS:RDVOL / 0.005 mA - BIAS:RDCUR.

Thursday, February 04, 2021, 10:14: 19.5 kV - BIAS:RDVOL / 0.005 mA - BIAS:RDCUR. 

Thursday, February 04, 2021, 10:20: 20 kV - BIAS:RDVOL / 0.005 mA - BIAS:RDCUR.  

FM

Thursday, February 04, 2021, 12:54:  20.5 kV / 0.006 mA 

Thursday, February 04, 2021, 12:58: 21 kV / 0.005 mA

Thursday, February 04, 2021, 13:02: 21.5kV / 0.006 mA 

Thursday, February 04, 2021, 13:08: 22 kV / 0.005 mA. 

Thursday, February 04, 2021, 13:12: 22.5 kV / 0.006 mA. 

Thursday, February 04, 2021, 13:58: 30 kV / 0.008 mA.

Thursday, February 04, 2021, 14:04: Spark. Bias is current limited.

Thursday, February 04, 2021, 14:39 : Small bright spot at the TGHT or HS cooling lines from the solder of the GND water lines.

Without voltage this is not noticeable. Likely a corona discharge happening at this location and hence limiting the current.

Opening to create clearance. Also to troubleshot the cathode power supply.

Thursday, February 04, 2021, 16:07: Turbos off.

Friday, January 29, 2021, 09:11: CANBUS controller was replaced. Quick systems check ok. Sources, HV, & Optics all good.

Friday, January 29, 2021, 10:05: HV & Ramping check.

Friday, January 29, 2021, 10:08:

On Tuesday the hard good vacuum level was changed from 7e-6 T to 1e-5 T to allow larger leak rates when testing FEBIAD.

Also this new level should allow faster heating rates (be mindful and cautious)

Work done as per WP C2021-01-19-9

 Thursday, January 21, 2021, 10:05: Anodeless Negative Bias On Surface Ion  Source, or ANBOSIS (still working on the acronym). installed to test energy spread vs position.

The SIS allow a more forgiving operation while calibrating such that other sources can have these type of measurements.

 Thursday, January 21, 2021, 10:43: Electrical connection make sense inside the source tray both with and without TIS. Anode confirmed to be on HV common through 9-pin.

Thursday, January 21, 2021, 10:46: Roughing.

Thursday, January 21, 2021, 11:17: Turbos on. 

Thursday, January 21, 2021, 11:25: IG1 on. 

 Thursday, January 21, 2021, 12:52: IG1@2.67e-5 T

AS

Friday, January 22, 2021, 07:04: Vacuum @ 4.57e-06T.

Friday, January 22, 2021, 07:07: FS#2 open. Vacuum ok @ 4.57e-06T

Friday, January 22, 2021, 07:13: FS#3 Open. Vacuum ok @ 4.57e-06T

Friday, January 22, 2021, 07:24: FS#4 Open. Vacuum ok @ 4.48e-06T

Friday, January 22, 2021, 07:30: FS#5 Open. Vacuum ok @ 4.48e-06T

Friday, January 22, 2021, 07:39: Reboot IOC (Optics page has a white out)

Friday, January 22, 2021, 07:44: Power / Sources on.

Friday, January 22, 2021, 07:49: Reboot PLC / IOC again. Surface source page ok. Optics page still in white out.

Friday, January 22, 2021, 07:52: Controls to TGHT / TBHT non-responsive. 10 / 5 A on TGHT / TBHT @ 0 / 0 A on epics & the PS.

Friday, January 22, 2021, 08:15: Tested HV. OK on both EZL & BIAS w/ 500 V each, then back to 0 V. TGHT / TBHT still not responding.

AS

Friday, January 29, 2021, 09:52: TS checks ok. Fixed. TGHT /  TBHT @ 10 A each. BIAS / EE / EZL @ 500 / -200 / 300 V to check.

 https://elog.triumf.ca/TIS/Test-Stand/842

Friday, January 29, 2021, 09:53: Auto-ramping TGHT / TBHT to 350 / 150 A @ 2 A per min.

Friday, January 29, 2021, 10:05: BIAS / EE / EZL @ 30 /-1.5/13 kV.

Friday, January 29, 2021, 10:08: Lot's of sparking*** Reduce BIAS / EE / EZL to 20 / -1.5 / 10 kV.

 FM

Friday, January 29, 2021, 11:24: BIAS / EE / EZL @ 29 /-1.5/13 kV.. No Sparks. Ramping up to 30 kV in steps of 100V.

Friday, January 29, 2021, 11:28: Reached 30kV on bias. No sparks after 2 minutes. Previously, the sparks happened within seconds after reaching 30 kV, according to the striptool.

Friday, January 29, 2021, 11:41: There were  five inaudible sparks. They are likely occurring inside as the target-ion source is being heated. Small rise in vacuum occurred and then the spark started.

Friday, January 29, 2021, 11:42: BIAS / EE / EZL to 0.000 kV to allow outgassing

Friday, January 29, 2021, 12:44  Auto-ramping TGHT / TBHT to 500 / 200 A @ 4 A per min.

Friday, January 29, 2021, 13:32: TGHT/TBHT @500/200 A.

Friday, January 29, 2021, 13:44. Spark on top.

Friday, January 29, 2021, 13:48 : BIAS / EE / EZL @ 30 /-1.5/13 kV.

Friday, January 29, 2021, 13:49: Anode gets current limited even at 1 V.  Could this indicate a short, or that the anode is floating?

Friday, January 29, 2021, 13:53: Spark across extraction electrode spark gap.

Friday, January 29, 2021, 14:13: Auto-ramping TBHT to 225 A @ 3 A per min.

Friday, January 29, 2021, 14:32: 10 min ago, the IG6 timed out. Nothing tripped but the epics couldn't restarted. Manually turned Fil1 on controller but didn't work. Fil2 did the trick. Back to normal.

Friday, January 29, 2021, 14:42: Spark gap again. It turned the separator section yellow (except MB1)"

Friday, January 29, 2021, 15:08: Auto-ramping TGHT to 580 A @ 2 A per min. Good vac level set to 3.5e-7T

Friday, January 29, 2021, 15:17: Inaudible spark. First spark after 25 min.

Friday, January 29, 2021, 15:30: Playing with TBHT current. Couple of sparks when playing with the steerers and einzel lens. TGHT auto-ramp waiting for good vacuum.

Friday, January 29, 2021, 16:25: Vacuum reached bad vaccum level. Currentes were step back. No sparks for around 40 minutes.

Friday, January 29, 2021, 16:41: System seems to be dirty. It will likely take the weekend to reach nominal vacuum levels.

I will reduce the HV and keep the heaters on. I will keep an eye during the weekend.

Friday, January 29, 2021, 16:44: 50 minutes without sparks

Friday, January 29, 2021, 16:46:  BIAS / EE / EZL to 0.000 kV to allow outgassing during the weekend.

Saturday, January 30, 2021, 11:59: Vacuum has steadily decrease over time allowing the auto ramp-up routine to make progress.

Saturday, January 30, 2021, 12:00 IG1 @ 3.58e-6T . TGHT/TBHT @  566/230 A. All voltage still at 0 V.

Saturday, January 30, 2021, 12:56: TGHT/TBHT @ 580/230 A. 

Sunday, January 31, 2021, 09:32: TGHT/TBHT @ 580/230 A. IG1@2.59e-6T. 

Sunday, January 31, 2021, 10:48:  BIAS / EE / EZL @ 30 /-1.5/13 kV. No sparks on the way up. Beam is now noticeable on the wire scanners, When I first tried with colder target current no beam.

Sunday, January 31, 2021, 13:31: After around 3 hours, only two sparks have occurred.

Sunday, January 31, 2021, 13:54: Spark. All of them seem to be going to EZL. 

Sunday, January 31, 2021, 15:13: Spark. Separators optics turned yellow. 

Sunday, January 31, 2021, 15:38: Spark. 

Sunday, January 31, 2021, 16:11: Things were looking good so i  decided t o try  a mass scan , however a series of sparks started. I set all biases to 0 and stop the tests for today.

Fernando Maldonado wrote:

Wednesday, October 30, 2019, 14:49: John C. changed the polarity of the anode power supply to negative, and Fernando M. rewired the cabling on the service cap.

 Wednesday, January 20, 2021, 11:26: John Chow verified that the power supply was in negative mode.

Just as side note, I think the PS was in negative mode since the quoted entry from October 30 2019. Given that the SiC/FEBIAD was supposed to run in cathode mode, the test stand was rewired to this. The only rewiring after this was for the P2N.

Fernando Maldonado wrote:

Yesterday, December 1st, I successfully installed and tested the gas system inside the faraday cage. The changes performed were as follows: Remove He gas tank (to make room for new tank) Remove calibrated leak to connect new gas line Remove convectron gauge to install a high range dial manometer.   The tests were done manually and consisted as follows: Gas lines roughed by opening SV1. Tank regulator set to deliver 1 bar SV4 opened to allow the gas to enter the lines Dial manometer verified to  match the pressure set by the regulator Alternatively roughed and pressurized the lines by opening/closing SV1/SV4 Tank lines emptied with SV1 and SV4 open simultaneously.   The test involve the lines up to SV5. The gas line portion from SV5 to the top of the HV cage was not included as it was removed for TM3 HV tests (se entry #822) When the HV tests are concluded I will install a new line that will include a gauge.

 Yesterday, January 13th I added back the gas line from SV5 to the service cap.

I temporarily added a gauge in between to measure the gas pressure. After successful tests I removed it from this location.

Finally, I added the gauge on the service cap, which its desired location (see attached picture). The tests corroborate no pressure losses from the gas bottle up to this location.

I have rewired the test stand (service cap wiring only, not power supply wiring) to anode bias mode as shown in the diagram. This was not how it was wired before, there are several things I have removed that appear to be newer additions. I also removed the burned cable between TBHT(-) and COIL(-), and between the multipin feedthrough and ground (probably related to the other burned cable).

I tried to measure the resistances across the feedthroughs (as opposed to across the resistors themselves) but they all seem wrong. I get 27Ohms across the TGHT and TBHT circuits instead of 100Ohms. Between the TGHT and TBHT I get 100Ohms as expected. Across the coil circuit I get 6Ohms instead of 100Ohms. Probably only the 6Ohms really needs to be fixed, but if the resistors are damaged, then the varistors might be as well.

Restarting TS after holidays & planned power outage.

Monday, January 04, 2021, 08:17: All epics controls in a 'white out' state.

Monday, January 04, 2021, 08:20: Rebooted PLC / IOC. Controls returned.

Monday, January 04, 2021, 08:22: Strip tools started / epics response ok.

Monday, January 04, 2021, 08:23: Switch on TMS:RP2 & TSG:RP1

Monday, January 04, 2021, 08:24: Open PV1 & PV2.

Monday, January 04, 2021, 08:26: Optics, steering, and archivers still in a non-responsive / 'white-out' state.

IOC rebooted on January 6. Controls returned to normal.

Shutting down the ISAC TS for the planned outage on Dec 22.

Monday, December 21, 2020, 07:50: Ion gauges & turbo pumps off.

Monday, December 21, 2020, 07:51: Confirm wire scanner shutoff.

Monday, December 21, 2020, 07:55: Waterlines purged.

Monday, December 21, 2020, 07:57: Backing valves TMS:BV6 & TMS:BV2 off. PV1 & PV2 off. Roughing pumps off.

Ramping up to 75kV. Started drawing current at 63.5kV this time.

Now at 75kV, drawing 5uA of current. Ramp up easy.

Thursday, December 17, 2020, 13:02

Been at 75 kV since about 8:45. A single spark at 11:58.

Thursday, December 17, 2020, 18:10

75 kV. No sparks since that last one 6 hours ago. Current has been slowly decreasing over time, now sitting around 2 uA. Was about 5 uA around the time of the spark. Starting ramp down. Dumped data.

Wednesday, December 16, 2020, 10:30 (Carla) :

Started ramping up about 45 mins ago, now at 50kV with no issues. No sparking, occasional current draw to get to the next voltage step. Test piece is no longer drawing any current, as opposed to yesterday when it was drawing around 4uA at this point. Trace left on insulator must have partially evaporated in the vacuum overnight.

Wednesday, December 16, 2020, 10:34 :

Starting to draw some current at 50.5kV. Drawing 4uA at 55kV.

Wednesday, December 16, 2020, 10:51 :

Back up to 60kV, no sparks so far and no issues, though it is still drawing 5uA of current, as it was yesterday.

Wednesday, December 16, 2020, 12:28 (Alexander)

No sparks at 60 kV for 1.5 hours. Starting voltage increases again at 250 V increments. Currently limiting current to 6 uA. Current draw is 4 uA.

Wednesday, December 16, 2020, 13:20

63 kV. Appears current limited, increased current limit to 7 uA. First spark was at 62.75 kV.

63.25 kV. Seems current limited again but eventually reached a stable voltage after a minute. Increased current limit to 8 uA for next voltage increase.

63.5 kV. Spark.

63.75 kV. Unstable trying to reach voltage, appears current limited. Small spark followed by a big one on the rise of the previous. Second one activated something pneumatic nearby. Reduced voltage by 250 V. Looked at vacuum system but nothing abnormal.

63.5 kV. Spark, not recorded on GoPro. Stable after 5 minutes. Continuing.

63.75 kV. No longer current limited and reached voltage stably. Dumped data.

Wednesday, December 16, 2020, 14:02

64.5 kV. May be current limited again, took over a minute to reach stable voltage.

Note: None of the sparks recorded today so far have produced a response in the vacuum, which is holding steady at 1e-6 Torr.

65 kV. Smooth transition to it. Drawing 5 uA.

65.25 kV. Spark after voltage instability and current draw at 8 uA limit. Moved the Faraday cup, which made a sound. This is the sound I heard earlier. Lower current draw after the spark, back at 5 uA.

Wednesday, December 16, 2020, 15:20

Stable at 65.25 for an hour, no sparks.

Spark at 66 kV. Current limited and unstable voltage for about 2 minutes afterwards, then stable with current back to 6 uA.

Spark at 66.5 kV after some voltage instability and current limiting. Afterwards current and voltage returned to stability.

67 kV, two sparks, one right after the other. The second produced a bump in the vacuum. Reduced voltage. Brought back up easily; current stable at 5 uA.

67.25 kV. Spark. No instability preceding it for a good 20 seconds.

67.5 kV. Spark. Instability before, none after.

Wednesday, December 16, 2020, 16:08

68 kV. Spark. Instability before, none after. Vacuum dropped about 20 seconds after recovering. Current also dropped to 4 mA, at about the same time the vacuum dropped. Dropping current limit to 7 uA.

68.25 kV. Vacuum jumped back up to earlier values and then an eventual spark after some instability. Returned to stability after spark. Current now at 5 uA.

68.75 kV. Spark.

69 kV. Carla went to look inside. Saw some small sparks towards the back between the HV sheath and GND sheath in the small gap side. Very little registered in EPICS, though. Just a couple jumps in current and small dips in voltage. Not visible in GoPro footage.

Wednesday, December 16, 2020, 16:38

69.25 kV. Two sparks. Stable after second. Third spark. Reviewed GoPro footage because third spark was suspicious. Appears on video but not near or on the prototype. Could have been the wire. Dumped data.

69.75 kV. Some instability paired with a change in vacuum for the same duration.

70 kV. Carla went to look. Nothing visible on the StripTool but Carla said she saw small sparks towards the back. Going to leave here for 20 minutes before raising again.

Wednesday, December 16, 2020, 17:12

Held for 20 minutes at 70 kV with no action. Starting voltage increases again.

70.25 kV. Two and a half minutes of voltage instability, raised vacuum, and limited current. All of them stopped and started at the same time. Seems like conditioning to me.

70.5 kV. Carla saw two very faint sparks towards the back on the small gap side. Little appeared in EPICS. Spark followed maybe a minute and a half later. 2nd spark four minutes after that. Before and between those sparks the current was generally at 5 uA. About a minute after the 2nd, the current dropped to 4 uA.

70.75 kV. Short conditioning (response from all 3 monitors) period of about 10 seconds.

71 kV. 2 sparks one minute apart with some conditioning in between and after.

71.5 kV. Spark followed by 2 minutes of conditioning.

71.75 kV. One minute of conditioning.

Wednesday, December 16, 2020, 18:06

72.25 kV. Spark followed by a minute and a half of conditioning.

72.75. About a minute of conditioning.

73 kV. Instant spark followed by about a minute of conditioning.

73.25 kV. 30 seconds of conditioning then a spark. 1 minute of conditioning, then another spark, and conditioning done right after. Second one sounded like it activated the Faraday cup.

73.75 kV. Sporadic and weak conditioning? A few blips in voltage and current over about a minute and a half.

74 kV. Similar to previous but even less significant.

74.5 kV. Two minutes of conditioning.

Wednesday, December 16, 2020, 18:52

75 kV. 30 seconds of conditioning. Spark. 2.5 minutes of conditioning. 2nd spark. 10 seconds. 3rd spark; lowering voltage by 250 V for stability to capture footage of previous 3 sparks. Stable here for 5 minutes.

Wednesday, December 16, 2020, 19:01

75 kV. Nothing happening. Gonna leave for 30 minutes.

Wednesday, December 16, 2020, 19:31

75 kV for 30 minutes. No sparks or any other anomalies. Vacuum has been around 9.5e-7 Torr. Current hovering around 5 uA. Starting voltage ramp down.

Wednesday, December 16, 2020, 19:43

Ramped down. Nothing interesting. Turned power supply off in EPICS. Still on physically such that ramp up tomorrow can start remotely. Dumped data.

Tuesday, December 15, 2020, 11:15

Vacuum at 1.0e-6 Torr. Turned bias power supply on, starting HV ramp at 500 V increments, increasing every 30-50 seconds seconds or so.

Tuesday, December 15, 2020, 12:47

Reached 50 kV. Not a single dip in voltage, significant current bump, or change in vacuum up to this point. Will hold for 10 minutes before continuing.

Tuesday, December 15, 2020, 12:57

Continuing voltage ramp. Decreasing increments to 250 V as this is uncharted territory, and that rate of increase seemed safe yesterday. Will also hold at each voltage for about 2 minutes after no signs of activity.

Tuesday, December 15, 2020, 13:04

Small dip in voltage and wiggle in current at 50.75 kV, no change in vacuum.

Spark at 51.25 kV with change in vacuum; reduced voltage temporarily. Did the same at 51.75 kV. Did the same at 52 kV, but let it sort itself out this time since it didn't seem too violent.

Actual spark at 52.25 kV with big voltage drop, and I saw it happen. On the vacuum gap side, somewhere in the flat plane and close to the middle. Another spark after about 3 minutes of holding. Just missed recording it but I saw it on the feed of the GoPro; maybe in a similar location as the previous. Another 1 minute later, didn't see it this time. The last two had no effect on vacuum.

Tuesday, December 15, 2020, 13:31

5 minutes since last spark. Raising voltage again, this time recording with GoPro. Spark captured at 53 kV. No change in vacuum... until a minute later.

Tuesday, December 15, 2020, 14:46

55 kV. Each time voltage is raised, it takes a couple seconds to reach a stable voltage. During this time the current limit of 0.005 mA seems to be drawn. Will reduce current limit to 0.001 mA to see effect. Dumped StripTool data at 55.25 kV.

Recorded spark at 56 kV. Voltage took longer to recover as a result of the reduced current limit.

58.5 kV. Effect of reducing current limit seems to make it take longer to reach a stable voltage. I think this is a good thing as it should smooth out the conditioning. Sparked here twice, reduced voltage for a bit before bringing back up again.

Tuesday, December 15, 2020, 16:23

60 kV. Sparked twice. Carla observed some: a couple small ones on the face of the insulator as the voltage was recovering from the first spark followed by a large one that went all the way across. Only the larger events seem to be captured by the GoPro.

Tuesday, December 15, 2020, 16:47

Finished holding at 60 kV to 20 minutes with no sparks other than the other two previously mentioned. Resuming voltage increases.

Tuesday, December 15, 2020, 17:02

61.5 kV. Small spark but not full breakdown, then a large spark that cut voltage to 0 V. Voltage dropped relatively slowly to about 48 kV. Lowered the voltage limit to 44 kV. During this entire time, 0.001 mA of current was being drawn. Carla started raising voltage while increasing the current limit as needed to reach the set voltage.

Tuesday, December 15, 2020, 17:44

Back at 60 kV and holding. Drawing 0.005 mA to 0.006 mA though. This is different from earlier when it was holding 60 kV with no current draw.

Tuesday, December 15, 2020, 19:02

Held 60 kV for an hour with current staying constant around 0.005 mA. Ramped down (first ramped down current to see effect) and then ramped down voltage. Shut off power supply.

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.

Test piece installed with Sam, Aaron and Alexander. Ended up shimming the support stand (middle foot) since it seemed to be bowing a bit and distorting the gap between the containment box stand-in piece and the service tray piece. We should measure the gaps when testing is done with the same configuration. Installation was not too hard, installed the whole thing as one piece. Had to remove the middle foot on the long side to get it through the door but otherwise no problems.

Test stand re-wired for HV testing. Wire hooked up to test piece by pinching between two tubes. Verified GND and HV continuity.

The copper tubes to be used in the TM3 test piece may have flux inside them from soldering the end caps on. There are holes along the length for outgassing, and we will try to bake them out in the test stand before installing them. There is still a dummy bake out target installed there, see the photo for how the tubes are loaded in. TGHT ramping started around 3pm.

I had to remove the grounding connections from the TGHT feedthroughs for this, so I redid them such that the tube is attached to the EZL. This target has no tube, so the connection between the tube and target is just through the 100Ohm resistor.

We must re-do the grounding before proceeding with HV tests.

Wednesday, December 09, 2020, 19:38 :

Target heater ramp down started. See attachment for vacuum progression during bake out.

Friday, December 04, 2020, 13:34

Vacuum is at 3.6e-6 Torr and possibly still dropping. Starting HV tests with just a tube and wire hanging down from the feedthrough. Turned on power supply and started raising voltage.

Friday, December 04, 2020, 15:13

Achieved 75 kV. No sparking at any point along the way. Vacuum is around 3.1e-6 Torr. Will hold for about 30 minutes to confirm.

Friday, December 04, 2020, 16:07

Held 75 kV for ~35 minutes. Ramped down and shut off power supply. Vacuum is at 2.7e-6 Torr.

Friday, December 04, 2020, 08:52 :

Test stand roughed down to 29mT overnight. Started turbos for testing later.

Thursday, December 03, 2020, 15:54 :

Got sign off from John Chow to run the system, though the nylon insulator was not ready when he came by. But we went over everything together.

Installed blue nylon insulator with all vacuum surfaces cleaned at least with methanol. No NPT fitting or tube installed, just testing service cap.

Thursday, December 03, 2020, 17:31 :

Tested voltage on the blue nylon insulator up to 75kV, left it at 75 for ~30mins. No sparking, no current drawn except occasionally when changing voltage and only ~1uA then.

Cleaned (but not very well...) the NPT fitting, copper tube, alligator clip and section of copper wire and installed these in the vacuum chamber. Will pump down overnight for testing tomorrow.

See attached photos for insulator setup and wire inside vacuum chamber.

Yesterday, December 1st, I successfully installed and tested the gas system inside the faraday cage.

The changes performed were as follows:

• Remove He gas tank (to make room for new tank)
• Remove calibrated leak to connect new gas line
• Remove convectron gauge to install a high range dial manometer.

The tests were done manually and consisted as follows:

• Gas lines roughed by opening SV1.
• Tank regulator set to deliver 1 bar
• SV4 opened to allow the gas to enter the lines
• Dial manometer verified to  match the pressure set by the regulator
• Alternatively roughed and pressurized the lines by opening/closing SV1/SV4
• Tank lines emptied with SV1 and SV4 open simultaneously.

The test involve the lines up to SV5. The gas line portion from SV5 to the top of the HV cage was not included as it was removed for TM3 HV tests (se entry #822)

When the HV tests are concluded I will install a new line that will include a gauge.