Posted on 05/13/2009 2:55:08 PM PDT by shove_it
lol
You mean they're going to use DC? ≤]B^)
Actually, they could.
Theyll reduce the voltage until the current they need to get the power tranmission they want creates just about a critical magnetic field within the conductor; i.e., the maximum field the conductive material will stand and still remain superconductive.
What that current density is for the materials they plan to use your corrsepondent knoweth not.
The rules for underground cable change when going from hi-tension to superconducting. Traditionally, the problem with underground is the insulation against hundreds of KV.
Since superconducting cables won’t be using that kind of potential, the challenge shifts to keeping the cable cryogenic, which is a whole lot easer to do underground than up in the air.
This is certainly true. The last time I looked they were getting superconductivity in materials a bit above liquid nitrogen. That's still pretty cold. I'm sure they are doing better now.
Back when I was just a young engineer we were using lead (yes just plain old ordinary lead) as a superconductor to provide a magnetic shield for a cryogenic ruby maser. That required liquid helium temperatures but that was OK since that was the temperature (a few degrees Kelvin) required for the maser itself.
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