Re: Can a standard copper core motor be replaced with superconductive wire?

Dear Thomas!

Yes, one can, in principle, replace the copper wire in a motor with superconducting material. You would have to go through a significant amount of `engineering' problems, though.

First of all, there is the problem of cooling the motor below T_c during its time of operation. Second, there is the problem of limited current and magnetic field `endurance' of the superconductor. If the current or the magnetic field gets too large, superconductivity will break down, with, depending on the parameters, sometimes hazardous consequences.

Wire made of High-T_c superconductors is available, though I do not know at which price.

The force between a superconductor and a permanent magnet depends on many parameters, including the magnetic moment of th magnet, but also the shape of it, so I cannot give a general answer to that question. The force between permanent magnets of some specific shape has been treated before in this forum, though.

Liquid hydrogen is a somewhat dangerous coolant - mixing it with oxygen in any way would, as you surely know, produce a very efficient explosive. It has a temperature of about 20K, which is unnecessarily low for High-T_c superconductors. Liquid nitrogen is a much better and safer choice here.

Here are some links which may get you going on the subject of superconductivity and its practical applications, including motors and such:

http://www.ncsl.org/programs/esnr/supercon.htm
http://www.superconductors.org/
http://www.eren.doe.gov/superconductivity/what.html

Hope that helps,
Georg.