 Monday, February 26, 2018, 09:13, Carla Babcock, , , , , , , , Running list of changes to the ISAC test stand for >60kV operation 6x
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1. Al corona shield installed over end of the HV duct to suppress discharges from the sharp edge of the duct.
2. Some moving and shortening of cables to keep them from running close to different voltages.
3. Changed the angle bracket on the 3M bias-EE resistor chain to a plate, same position. |
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Friday, February 23, 2018, 08:50, Aaron Schmidt, , , , , , , , New Al Corona
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| Friday, February 23, 2018, 08:50 |
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Tuesday, February 20, 2018, 09:04, Carla Babcock, , , , , , , , Trying HV with rubber corona shield
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Tuesday, February 20, 2018, 09:01: Sparks at 62.5kV after a couple minutes. Sounds like they were in the EE spark gap but don't appear on the EE read
current. Ozone smell around 61kV, so there are still some discharges.
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Monday, February 19, 2018, 14:01, Carla Babcock, , , , , , , , Attempts to get to higher voltages, summarized.
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The test stand holds up to 63kV, however at voltages over 54kV there are small discharges, rising to a continuous level around 60kV. The best guess right
now is that these are coronal discharges coming from the end of the HV duct to the faraday cage. The only way to fix this would be to round out the edges
of the duct, or to move the duct farther away. Since I have heard small discharges in other places, we may need to make a variety of modifications. Things |
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Monday, February 19, 2018, 08:30, Carla Babcock, , , , , , , , TMSTP6 off
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| Found TMSTP6 off, restarted it, seems fine now (drawing 0.8A) |
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Friday, February 16, 2018, 15:21, Carla Babcock, , , , , , , , Cleaned HV cage - trying bias again
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I vacuumed inside the HV cage, though it has many small areas that are difficult to access so I am not sure how great a job I did.
Turned the bias up and again at 55kV I hear small sparks near the end of the HV duct that brings the cables from the rack. Cannot see anything.
If it is really sparking where it sounds like sparking, it must be from the edge of the duct to the faraday cage. |
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Tuesday, February 13, 2018, 16:47, Carla Babcock, , , , , , , , Ramping to 63kV - some sparks
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Sparks at 62kV on the bias.
Turned it down, turned it back up and got a spark at 60kV.
Now up to 63kV, no sparks so far (5 mins). Left EE @ -3100V and EZL @ 28.5kV |
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Tuesday, February 13, 2018, 12:17, Carla Babcock, , , , , , , , Ramping up bias to 60kV with conditioning station supply
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Ramped up to 60kV with the new power supply, same as what we did last time with the standard test stand bias supply (see entry #627 ). Much more instability
on the bias current readout (see attached screen shot), develops around 54kV. As well, the old supply read out 37uA at 60kV while the new supply reads
out ~85uA. This could just be an EPICS read back issue though. |
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Friday, February 09, 2018, 08:57, Carla Babcock, , , , , , , , TSGBIASSAFETY ok interlock
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Friday, February 09, 2018, 08:25 Disconnected the AC power chain from the old bias supply but now cannot turn on the new bias supply
in EPICS because the "TSGBIASSAFETY ok" interlock is tripped. No idea what this means - maybe it checks for AC power?
Friday, February 09, 2018, 08:48 Reconnected power to old bias supply, does not fix problem. Talked to Mike, he thinks it is |
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Thursday, February 08, 2018, 16:54, Carla Babcock, , , , , , , , EZL strange behaviour
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Thursday, February 08, 2018, 16:54
Testing the HV bias I found that the einzel lens was behaving strangely. When I tried to put it higher than 1kV, the current would start spiking
from 12uA to > 100uA. The voltage would jump around quite a bit as well (+/- 100V). Everything seems the way it was before, except the EZL power supply |
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Thursday, February 08, 2018, 14:44, Carla Babcock, , , , , , , Done, Conditioning station power supply integrated into EPICS
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| The 75kV power supply is now in EPICS under the usual TSG:BIAS controls. The upper limit has been set to 70kV to protect the transformer. |
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Wednesday, February 07, 2018, 08:46, Aaron Schmidt, , , , , , , , BIAS Power supply installation
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Wednesday, February 07, 2018, 08:40: A 75 kV Glassman power supply was installed in the rack for use in further HV testing.
-The 75kV power supply is linked into the keyed interlock system. The key & switch labelled BIAS/EZL will unlock it.
-The PS is currently not connected to the epics controls and can only be adjusted manually. |
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Monday, February 05, 2018, 09:17, Aaron Schmidt, , , , , , , Problems/Solutions, Epics loss
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Monday, February 05, 2018, 09:10: the epics program was in 'White-out'. Turbo pumps tripped.
Unplug, re-plug PLC.
Monday, February 05, 2018, 09:16: Restart Turbo pumps on chamber & beamline. |
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Wednesday, January 31, 2018, 12:58, Aaron Schmidt, , LP-SIS, , , (Blank), 42752-3, In progress, HV test 4
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Wednesday, January 31, 2018, 12:53: Power/sources on.
Wednesday, January 31, 2018, 12:58: BIAS / EZL / EE @ 40 / 17 / 2
Wednesday, January 31, 2018, 13:02: BIAS / EZL / EE @ 40 / 17 / 2 |
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Wednesday, January 31, 2018, 09:53, Aaron Schmidt, , , , , (Blank), 42752-3, Done, Wire moved.
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Wednesday, January 31, 2018, 09:50: A wire (B - F) was too close (Almost touching) to the EZL and had visible sparks during HV tests 1 & 2. The wire
was adjusted to sit higher. and away from the EZL |
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Tuesday, January 30, 2018, 06:51, Aaron Schmidt, , LP-SIS, , , (Blank), 42752-3, Done, HV test 3
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Tuesday, January 30, 2018, 06:50: BIAS / EZL / EE @ 30 / 13 / 1.5
Tuesday, January 30, 2018, 06:52: Auto ramping TGHT / TBHT to 580 / 200 A @ 2A per min.
Tuesday, January 30, 2018, 06:58: Optics on / set |
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Monday, January 29, 2018, 10:07, Aaron Schmidt, , LP-SIS, , , (Blank), 42752-3, Done, Power outage / HV test 2
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HV test 2 cancelled. 9:38: BIAS/EZL/EE @ 30/13/1.5 kV
Monday, January 29, 2018, 09:40 (Roughly) Power went out completely
Monday, January 29, 2018, 10:00: Power up TS |
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Friday, January 26, 2018, 13:59, Aaron Schmidt, , LP-SIS, , , (Blank), 42752-3, Done, HV test 1
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Friday, January 26, 2018, 14:00: BIAS/EZL/EE ramp up.
Friday, January 26, 2018, 14:06: BIAS/EZL/EE @ 30/13/1.5 kV.
Friday, January 26, 2018, 14:09: BIAS/EZL/EE @ 35/13/1.5 kV. |
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Friday, January 26, 2018, 11:10, Aaron Schmidt, , , , , , , Done, Helium tank replacement
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Friday, January 26, 2018, 11:08: New Helium tank installed inside the Test Stand.
-The 'Full' tag remains. The He tank was not opened.
-The old tank was placed beside the Test Stand beneath/beside the power switch. |
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Monday, January 22, 2018, 09:04, Aaron Schmidt, , , , , , , Done, Power outage & Controller replacement.
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Computer, TS, epics, restarted. Power checks
Monday, January 22, 2018, 09:00: ISAC PLC TLCIOC Restarted.
Turbo pumps restarted. |
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