In article ,
Ian Stirling wrote:
Gregory L. Hansen wrote:

snip
I'm actually kind of disturbed that the LN2 boils off so quickly, I don't
think a good design should do that. But I have what I have.

Are you sure the vacuum (if any) is pumped down right?
Even a small leak will ruin a vacuum bottle.

The liquid helium will last almost two weeks and the liquid nitrogen can
barely last until Monday morning if I fill it on Friday night, and it
holds more nitrogen than helium. So I don't know what the deal is.
--
"Let us learn to dream, gentlemen, then perhaps we shall find the
truth... But let us beware of publishing our dreams before they have been
put to the proof by the waking understanding." -- Friedrich August Kekulé