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DEWARs, SF6 and paper-caps
Hello all,
In my quest for strange but needful artifacts I've decided that I can't
live without a dewar. Seriously, I've planned doing some experiments with
very cold electrodes and efficient cooling.
I've looked at some quite reasonably priced ones and especially UNION
CARBIDE CRYOGENIC Model LR-21 for 125usd sounds truly reasonable if one
does not mention the postal fees to Finland.
Anyway, the real question is how should one test the unit? Apparently they
are vacuum-insulated (?) so the vacuum integrity is a must. Are these
usually ok when there is no visually perceivable damage? Anyone with
experience on using these? how long will, say 5 liters, of liquid nitrogen
or argon stay in the 21 liter container before evaporating completely?
btw: about SF6 - I'm working on that project too. I recently acquired an
excellent paper (doctoral thesis) : "Influence of conducting particles on
the SF6 gas gap breakdown and spacer flashover in gas" written by Mr. Li
Ming. Of course, it's not directly about building capasitors but has loads
of useful information. Cost was 2usd (!) as the local library sold some
old documents; got another excellent book as well : "dictionary and
excyclopedia of paper and paper making" so anyone working with paper-caps
and needing info on paper - feel free to ask.
Thanks a lot for any dewar-notes,
Kristian Ukkonen.
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| Kristian Ukkonen | Do as thou wilt shall be the whole of the law |
| kukkonen-at-alpha.hut.fi |_____ Chance favours the prepared mind |-------
| http://www.hut.fi/~kukkonen | Fear is the mind-killer |---------
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