"Jim Stewart" wrote in message
...
Umm, no. There's a surprisingly low critical
current density where the superconductivity
disappears.

As I recall the critical field is up around 20T in the tougher
superconductors, I don't know what field is present at and slightly inside
the conductor's surface for a given current and diameter though. Suppose I
should drag out our old friends Biot-Savart and Mr. Integral...

Tim

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