I just not too long ago started maintaining the magnet here, and have come
against a question that I've had for some time now. Everywhere I've been,
people use rubber hoses to transfer LN to the magnet dewar from the storage
dewar. Does anyone use anything different? I have used kind of a jacketed
stainless line to get LN into a smaller dewar for pump traps and the like,
but I've never seen a LN inlet fitting (top hat) for an NMR magnet with
something other than a hose barb (or just a straight piece of Al tube), as
opposed to say a flare fitting or a pipe thread.
In case it matters, the system here is a Varian Gemini 2000 with an
aluminum shell Oxford 300 magnet.
Anyway, if anyone has any thoughts on this matter, feel free to e-mail. If
there is enough general interest in the topic I'll summarize.
Bill
P.S. I have this nasty feeling that this issue has been raised before, but
looking back in the past two years I couldn't find it.
Bill Newcomb Argonaut Technologies
Research Associate San Carlos, CA
Analytical instrumentation nuke@argotech.com