Hello all,

TM2's first performance in the Conditioning Station with the new source tray was not great, with sparking and HV degradation beginning to occur at 30kV:
https://elog.triumf.ca/TIS/RH-ISAC/1039

This is perplexing, because the module without the source tray performed well at the TCS:
https://elog.triumf.ca/TIS/RH-ISAC/829

AND the new source tray performed well at the test stand (i.e. not inside the module):
https://elog.triumf.ca/TIS/Test-Stand/447

Upon inspection back at the Hot Cell last week after the failure, David Wang was observant enough to notice that one of the steerer coax wires (ground plane) was essentially touching one of the FEBIAD gas lines (HV plane) in the new source tray installation (photo attached).  Closer inspection by a group consisting of Anders, Alex, and myself revealed some apparent tracking and damage to the wire sheath.
https://elog.triumf.ca/TIS/RH-ISAC/1045

We believed at this point that the bad HV performance of TM2 was due to this problem.  The wires were originally arranged loose as it was believed it would be easier to install them in the Hot Cell this way.  However, it turned out to be a bad decision, as the wires at ground ended up becoming stray and touching the HV surface.

To correct the problem, the old wires were removed, and a new steere wire bundle was made using a PEEK material sheath.  This new sheath bundle was installed over the last day or so.  The penning gauge wire was kept separate from the steerer wire bundle.  You can see the new wire bundle and penning gauge wire in the attached photo, now with a healthy clearance to the FEBIAD gas lines.

Chad has been instructed to re-install the Einzel lens wire, install the new ZrC target, and replace the containment box in preparation for transport back to the TCS for another HV test.  If anybody would like to see the source tray today before ~3pm, I have asked Chad to wait for my final OK to put the containment box back on the module.

I apologize for this problem.  We are hopeful the solution we have installed will improve the HV performance.  Much work over the last 2+ years was put into building and installing this source tray by many contributors inside and outside of Remote Handling, and we want this module to succeed more than anybody!

Thanks and best regards,

Grant