Superconducting tesla coil

From:  Scott Stephens [SMTP:stephens-at-enteract-dot-com]
Sent:  Sunday, April 05, 1998 3:35 AM
To:  tesla-at-pupman-dot-com
Subject:  Re: Superconducting tesla coil

>Tesla List wrote:
>> ---------- Forwarded message ----------
>> Date: Sun, 29 Mar 1998 13:38:30 EST
>> From: ESchulz531 <ESchulz531-at-aol-dot-com>
>> To: tesla-at-pupman-dot-com
>> Subject: Superconducting tesla coil
>> Just as an idea what would happen if you used superconductive wire for the
>> secondary and the primary?  Q would go towards infinity, so how would you
>> it?  There would be no losses due to resistance so you could use really small
>> wire and have lots of insulation.

>>I wander if anybody on the list has funding to try this?

Some heavy ion particle accelerators use superconducting resonant coils made
from Niobium Titanium alloy. They are around 1" bar bent into a kind of
spiral, in a barrel of liquid Helium. They buzz around 70MHz, and are in a
phased array to accelerate heavy ions flying through them. They said it took
a million $$$ a day to keep them cool with liquid helium. The cryostats sing
a little tune when valves turn the He on to dissipate heat buildup.

Also, near-microwave filters used in cellular phone base stations are now
using high TC (thats Temperature-Critical) superconductors for high Q
(1000-10,000 I think) input filters. It is cost effective to use
stirling-cycle coolers to refridgerate them, because cellular RF spectrum
(900MHz) is limited and valuable. Using high Q filters made from
superconducting ceramics allows channel spacing closer than 21 10KHz
channels. More channels, more phone calls, more $$$. Conventional components
could be used but would mean many elements and tuning and component
tolerance nightmares. These filters, sadly, can't handle high power. Type 2
superconductors, I think, can't handle the high fields type 1 low-TC's do.

But since your Q drops to 10 when your burning air into ozone plasma, who
needs a superconductor? Unless, you wan't to store a hell of a magnetic
impulse ;-)

My favorite application for appropriate superconductors would be 2 large
flat pancakes, that would form a resonant cavity. Energy is coupled into the
cavity. As the field strength in the cavity grows, the pointing vector field
force forces the plates apart. An elevator ride into space. Just keep those
plates parallel!