Flux Pinning in a type 2 SC Using an AC Electromagnet

[AniV]

When a supercooled type two superconductor is subjected to a static magnetic field, the superconductor pins to the flux of the field (the mixed-state meissner effect is apparent).

What happens if it is subjected to a continuously changing magnetic field, assuming the superconductivity takes place after the field is introduced (flux already passed through before the superconductor became superconducting, which with DC current would result in a stronger pinning force)?

What would happen if the changing field is not sinusoidal, only changing slightly without ever reaching 0v?

 

[marcusl]

What do you mean by supercooled (which applies to water vapor)? I assume you just mean that it's superconducting? If the field strength changes slowly enough, then you can treat it as though it is a DC field at every time.