3 ms·
is that because R is never quite 0, meaning that higher A causes heat which raises the temperature above the superconducting level?
by clort 10y ago
is that because R is never quite 0, meaning that higher A causes heat which raises the temperature above the superconducting level?
- Panoramix 10y agoAFAIK the resistance is truly 0. However, there is a critical magnetic field, which if exceeded will destroy the superconducting state. Therefore a current large enough to generate this field will also destroy the superconductivity.
- WJW 10y agoThis is correct. Resistance in a superconductor is exactly zero. However if the current reaches a critical level the superconductor will ["quench"](https://en.wikipedia.org/wiki/Superconducting_magnet#Magnet_quench https://en.wikipedia.org/wiki/Superconducting_magnet#Magnet_...) and rapidly drop out of the superconducting state. When that happens, it regains its normal resistance and because there is still a lot of current going through it, the material will heat up rapidly, thus pushing it away from superconductivity even further. This can damage or even destroy the coil if the energies involved are large enough.