Conditioned TM2 up to 48kV in ITW. Some sparks and current is not very stable. Drawing about 178uA at 48kV.

TM2 TiC#6 post run electrical check has been done at TCS. See attachment

PIE on TiC#6 was done in the NHC. The target assembly looked brand new when we took it out, no heating spots or deposits (pictures on docushare). Online we measured a 400kOhm connection between TGHT-TBHT-COIL to HV common (TGHT and COIL shorted in TM2 service tray) and anode was unstable above ~300V. After the module move and before the target removal David found TGHT-TBHT-COIL was a dead short to HV common and the anode was at 39kOhms to HV common.

1. Wanted to see if the TGHT-TBHT-COIL short was on the COIL. Measured with ohmmeter the COIL lines to HS and got about 700Ohms. But with the target lying down the COIL lines drop and touch the heat shield so to do this measurement Chad had to lift the lines, which could cause them to touch something else. So not sure how reliable this measurement was. It jumped around a lot, saw 0L occasionally.

2. Measured both target legs and tantalum gas line to HS, got about 5kOhms repeatedly using the ohmmeter.

3. Meggered across the gas line insulator to the gas line going into the target and got open circuit at 250V, so the gas line wasn't coated.

4. Target container looked vaguely red in the areas where the target material was, otherwise still no deposits on the inside. The container was not overly crystalized as seen on the legs and end caps.

5. Some sparking marks on the EE and some slightly asymmetric deposits

Continuing Aug. 22 2023:

6. Found what looks like a hole in the insulation on the COIL, maybe the cause of our short? Found a corresponding line mark on the copper plates that hold the coil down but not sure if it is related. Pics on docushare.

7. Grid looks perfectly new. Where was that current going?

8. Copper plates that hold coil were loose and bolts that hold coil in just fell out as well.

9. What can be seen of the anode wire looks good.

 TiC #6 moved from north hot cell to spent target vault placed in pail #232 put in spot 6A and the field was 151mSv/hr when removed from the north hot cell. See attached PDF for details about spent target vault.

 TM4 with target TiC#5 installed has been leak checked and electric checked on NHC.

 TM4 was connected in ITE.  pics attached FYI.

Yesterday and today module conditioning was done on Tm4 in ITE. This is the first ramp up after the shutdown and ITE is planned to run at high voltages for the first weeks. The module is behaving well - went up to 40kV yesterday, stayed there for an hour, and up to 46kV today. Current draw is 113uA at 46kV. No serious sparking.

Tuesday, May 23, 2023, 09:32 :  Ramping up again, easy to 45kV. Drawing 132uA at 49kV. Still behaving quite well.

When I tried to raise the anode voltage in cathode bias mode on May 23 evening, I found the target or tube shorted to HV common. Investigations in the faraday cage today showed the same. I removed all the new electronics (resistors, gemovs, etc) from the power supply to no effect, so I disconnected the TGHT supply and pushed it away from the busbars. There was still a short. David Frank and I then went down to the pit and disconnected everything to measure the module. The module itself showed no short, and the bus bars in the chase for TGHT showed no short, though the ones for TBHT still showed the short.

David and Frank reconnected the module and I disconnected the TBHT supply in the faraday cage, then I found no shorts to TGHT/TBHT. When I reconnected everything there were still no shorts. There must have been a short in the TBHT line in the faraday cage, and another short in the TGHT line in either the faraday cage or on the module top. Both these shorts got resolved by taking everything apart. Still not sure how it happened.

Next I found I could not raise the anode voltage above 230V, it looked like it was current limiting but since the current limit was high, I figured it had something to do with the new electronics installed. I disconnected them all the in cage and that solved the problem, and then reconnecting the gemovs that go from the PSU terminals to HV common caused the problem again, so I left those disconnected.

argon is being supplied at 6 psi to TM4. 

 TM4 with TiC#5 was disconnected in ITE and moved to NHC.

 TM4 with spent target TiC#5 electric check after moving from ITE to NHC.

 TiC#5 moved to the spent target vault from the north hot cell. Placed in pail#279 in spot 3A, 40mSv/h when removed from NHC. See attached PDF for further details.

The TiC#5 post irradiation inspection was done on Wed. June 14 and Mon. June 19. This target didn't have any obvious issues but it didn't produce much beam. The inspection revealed that the container was quite embrittled and showed significant damage, though it was not broken. The FEBIAD grid looked fine, despite the large anode current draw (indicating that current was flowing elsewhere). The gas line looked fine though the gas injection to this target looked as if it wasn't connected. But there was a plug on the unused line, so it must have been correct. No other obvious signs that would explain the poor performance. Pictures are can be found here https://documents.triumf.ca/docushare/dsweb/View/Collection-37913

Electrical test of TM#3 with TiC#4 attached. See PDF.

TiC#4 has been installed onto TM3

TM#3 with TiC#4 has been moved from the south hot cell to the conditioning station.

 The TiC#4 target that is on TM3 was conditioned to 25kV today with the EINZEL lens at 12.5kV. There was one spark shortly after reaching 25kV that reset the bias PS and another one  after the module sat at 25kV for ~30 minutes. Attached is the strip tool data and screen shot. Prior to starting the conditioning the power on the chiller needed to by cycled as the VFD on the fans had tripped due to a recurring inrush problem.

TM#3 with TiC#4 has been moved from the conditioning station to the east target station.

TM#3 with TiC#4 has been moved from the east station to the south west silo.

TM#4 with TiC#4 has been moved from the east target station to the south hot cell.