Re: Superconducting tesla coil...

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Jim Lux <jimlux-at-earthlink-dot-net> 

Having done experiments along these lines, for those contemplating using 
LN2 and immersing a TC....

At 05:55 PM 10/2/2003 -0600, you wrote:
>Original poster: The MCP <ejkeever-at-comcast-dot-net>
>Heck, liquid nitrogen isn't *that* expensive, is it?

LN2 == Milk as far as cost goes... $.50/liter... $100 gets you a big GP45 
dewar (that's 45 gallons, folks)




>  But I'd want to be
>careful that my components have similar thermal expansions. Use something
>with a large theremal expansion coefficient as your winding on something that
>doesn't, and you'll get broken/stretched wire as the wire shortens and tenses
>up.

Precisely the problem you'll have... particularly things that are plastic, 
aren't when cooled to 77K...


>Other than that, you'll have to construct a vessel around the coil to contain
>the LN2.

Styrofoam is your friend... Those inexpensive plastic water coolers from 
Home Depot work quite well to hold LN2.  However, seal up the hole where 
the spout is at the bottom before filling.. if it starts to leak, you'll 
never be able to patch it.  Putty or epoxy works fine.

I'd try using something like sonotube in a larger sonotube (or 5 gal 
plastic buckets) with the space between filled with "foam in a can" or 
expanded vermiculite/perlite



>Reminds of an interesting reference from Ben Bova's Moonwar. They refer to the
>mass driver as using "cryogenic aluminum" magnets rather than
>supercondcucting magnets. When was the book written; The first high-temp
>superconductor was created in the early 80's, right?


High power magnets have used LN2 cooling for many years.