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.

Electrical check of the TiC#4 on TM#3 post beam at the south hot cell, see attached PDF for details

When the Containment Box was opened today by Chad for a target change, we found the conductor insulator block B (ITD0054) to be broken close to the right TGHT terminal. Chad was nevertheless able to remove the target. See DocuShare and attached file for photos.

An attempt to replace the insulator will be made tomorrow with a spare.

A small sticky piece, likely off plastic material, was found next to the left main source tray insulator. The piece was removed from the Containment Box. See link above and attachment for photos.

See attached pdf and DocuShare for more photos. It may be possible to clean some of it from the Ground Electrode.

Anders Mjos wrote:

When the Containment Box was opened today by Chad for a target change, we found the conductor insulator block B (ITD0054) to be broken close to the right TGHT terminal. Chad was nevertheless able to remove the target. See DocuShare and attached file for photos. An attempt to replace the insulator will be made tomorrow with a spare. A small sticky piece, likely off plastic material, was found next to the left main source tray insulator. The piece was removed from the Containment Box. See link above and attachment for photos.

 The two insulators ITD0053 and ITD0054 was replaced this morning by Chad. Photos on DocuShare. All bolts torqued with torque wrench see attached PDF for values.

 See attached PDF. The object is not accessible with only the front panel removed. Photos on DocuShare.

TiC#3 sucessfully installed and ready for leak and electrical check.

TM#1 with TiC#3 target has had the electrical performed on it. See attached PDF for details.