[Chris K]

Originally Posted by Yamamaya42

From what I understand, it takes a vacuum pump setup an order of magnitude higher than what you have used before.
https://en.wikipedia.org/wiki/Ultra-high_vacuum
Something I believe that ETF inherited from Hawkeye, and even after that, the inside of the neck is flashed with a very reactive material like barium, zirconium, titanium, and aluminum, and so on, anything to soak up what the pump could not pull out, or what is stuck to the elements.
As far as the gun itself, that's the hard part, replace the tired cathode, with the correct active surface on it, that also must be activated, the grids may be reused in most cases, put it all carefully back together hope that it all lines up, no cracks or leaks. Risky Business !

Thanks for the info and the link although I doubt the extent of vacuum associated with UHV is needed. UHV is more for high energy physics applications and it's hard for me to believe the machinery and sealing surfaces shown in the video can pull anything close to UHV levels. That being said, I agree with you typical lab vacuum pumps, even in series probably won't cut it. The ETF has one of these evac pumps? The one in the video was 2 stage. I'll need to look at the closeup of the gauges again to check the levels. Unfortunately, the camerawork in the video is pretty poor with significant operations being performed out of frame. I received a PM from the individual at RACS in Paris who did the training and I'm going to open a discussion via email with him. He related Nick's situation and responsibility challenges so I better understand the current state of the project.