Re: Superconducting magnifier

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: Re: Superconducting magnifier
From: Tesla List <tesla-at-stic-dot-net>
Date: Sun, 9 Nov 1997 13:14:16 -0600
Approved: tesla-at-stic-dot-net

From: 	Ted[SMTP:tedric-at-generation-dot-net]
Sent: 	Sunday, November 09, 1997 3:19 AM
To: 	Tesla List
Subject: 	Re: Superconducting magnifier

>From: 	Jim Lux[SMTP:jimlux-at-earthlink-dot-net]
>Sent: 	Tuesday, November 04, 1997 10:13 AM
>To: 	Tesla List
>Subject: 	Re: Superconducting magnifier
>
>
>> As I understand it the superconducting effect is destroyed by intense
>> magnetic fields because they destroy the electron coupling. Since
>> powerfull feilds are the aim in Tesla coils, I don't think that any sort
>> of superconducting system could work, sorry to dash your hopes, but
>> that's physics for you.
>
>I don't think the magnetic field in a tesla coil would be high enough to
>quench the superconductor.  Your problem would be constructing a dewar that
>is insulating electrically for the voltage required, and will still hold
>the LHe or LH2, and not pick up too much frost on the outside. Perhaps a
>little creative glass blowing? And, as I recall, most LHe dewars have a
>radiation baffle(s) inside as well as LN2 layers. I am not up on the latest
>in LHe dewar technology though; with all the superconducting MRI's there
>has been a lot of development on LHe cryostats and refrigerators.
>
>However, submerging the tesla coil in LN2 might be interesting. LN2 is a
>fairly good insulator, it is cheap ($.30/gal in large quantities, $2.00/gal
>in small) and at 77K, the resistance of the copper windings will be very
>low, so you should get real low losses and very high Q, which should give
>you good performance.


Jim,

I realize the insulation problem too, but it can be solved by using Teflon
since it is useful at sustained temperatures as low as -200 C. Although it
is costly, a thin container is all that is needed. If one is willing to pay
for the superconductor, I don't think price will be too much a concern for
him/ her. Outside the container, polyethylene foam will be used. And the
whole thing will be protected in a high density polyethylene shell. Also,
forget polycarbonate (if you want to use it), it will shatter like glass at
-20 C, and -40 C for the high quality one. 

Insulation is not my biggest concern, I will rather spend more time on other
problem such as the heating effect (Peltier Junctions?) between the
connection of the secondary and ground. 

Right now, I am pondering over this: "Liquid oxygen is magnetic and is an
insulator (no eddy current). Will using liquid oxygen as core material
improve the coupling? And what about using an oudin coil to power an extra
coil?"


Ted