%0 Journal Article
%J Physical Review B
%D 2011
%T Theory of flux cutting and flux transport at the critical current of a type-II superconducting cylindrical wire
%A Clem, J. R.
%K critical-state model
%K cylinder
%K force-free configurations
%K HARD SUPERCONDUCTORS
%K helical vortex instability
%K line
%K longitudinal magnetic-field
%K losses
%K surface
%K vortices
%M ISI:000291432700008
%P 214511
%R 10.1103/PhysRevB.83.214511
%U ://000291432700008
%V 83
%X I introduce a critical-state theory incorporating both flux cutting and flux transport to calculate the magnetic-field and current-density distributions inside a type-II superconducting cylinder at its critical current in a longitudinal applied magnetic field. The theory is an extension of the elliptic critical-state model introduced by Romero-Salazar and Perez-Rodriguez. The vortex dynamics depend in detail on two nonlinear effective resistivities for flux cutting (rho(parallel to)) and flux flow (rho(perpendicular to)), and their ratio r = rho(parallel to)/rho(perpendicular to). When r < 1, the low relative efficiency of flux cutting in reducing the magnitude of the internal magnetic-flux density leads to a paramagnetic longitudinal magnetic moment. As a model for understanding the experimentally observed interrelationship between the critical currents for flux cutting and depinning, I calculate the forces on a helical vortex arc stretched between two pinning centers when the vortex is subjected to a current density of arbitrary angle phi. Simultaneous initiation of flux cutting and flux transport occurs at the critical current density J(c)(phi) that makes the vortex arc unstable.
%Z 775BVTimes Cited:0Cited References Count:49
%8 06/09
%@ 1098-0121