The behaviour of type II superconductors

Publisher Website
Google Scholar
Abstract
By treating the flux lines in a type II superconductor as a compressible fluid Friedel et al. (1963) have shown that, for a non-uniform distribution of lines, the force per unit length acting on one line is (φ04π). dH(B)/dx. Here B is the induction at x and H(B) the external field which would be in equilibrium with B if the material were reversible. The flux lines in an irreversible type II superconductor in the critical state of Kim et al. (1963) are in virtual equilibrium under the forces due to the flux concentration gradient and a pinning force F. F arises from the interaction between the flux lines and structural defects in the material. It follows that F = (φ0/4π)(dH/dB) a(dB/dx) s, where (dH/dB) a is the gradient of the reversible B/H curve and (dB/dx) s the field gradient in the specimen.

This publication has 3 references indexed in Scilit: