[NewCandle] Vacuum, outgassing, etc.

[Kyle R. Mcallister]

All,

Anyone here with experience working with vacuum?

Questions:

1. Anything good to seal (semi-permanently, should hold 0.1 torr for at 
least a few months) metal to glass? I am no glassblower, so I'd prefer 
not to go down that route.

2. What metals outgas the LEAST in this moderate vacuum environment?

I am capable of pulling a decent vacuum for making homebrew Crookes 
tubes, and have built quite a few. But I'd like to be able to seal it 
off from the pump, and have it standalone. I did this a short time ago 
(read: 1 hour) and the tube still works. Seal off was made by heating a 
glass tube epoxied to the side of the bottle where a hole was drilled. 
The tube softened and collapsed, at which point I used the flame end to 
narrow the dimple further, so I could snap it off. The tube, so far, 
holds vacuum and makes a nice electron beam.

Are there epoxies or other substances (what did they used back in 
Crookes' time??) to seal a 0.1 torr vacuum in?

The cathode is brass, the anode copper. I seem to remember reading that 
they were bad choices. Oops. What's good to use?

--Kyle