Superconductor ring: shielding currents in different directions

[annaphys]

In this photo you see on the right-hand side that the outer wall current is negative and the inner wall current is positive. That is, they are directed in different directions. But if the applied magnetic field is in the z direction as shown, then shouldn't they both be in the same direction do to the fact that j_s = -j = rotB? That is the shielding current goes in the opposite direction of the current caused by the magnetic field. Why is it so that the currents are in different directions?

 

[annaphys]

Another question, why is rotB=mu*j_s? Shouldn't j_s would against the magnetic field so it should that rotB= mu*j where j = -j_s?

 

[annaphys]

Nevermind I understand it. My assumption from the beginning was wrong. There isn't a continuous homogeneous mag field in the photo just the trapped field.