CHAIN MODEL FOR THE SPIRAL INSTABILITY OF THE FORCE-FREE CONFIGURATION IN THIN SUPERCONDUCTING FILMS

The developed stage of a spiral instability of the magnetic flux line in a thin film is studied. The instability of a one-dimensional (1D) A ux-line lattice parallel to a thin superconducting film surface and to a transport current is modeled as a transformation of initial linear flux lines into chains of 2D vortices crossing the film and tilted in the held direction. The pitch length of the first instable spiral-like chain structure turns out to be of the order of a film thickness at a ll fields, which leads to a dissipation rate comparable in magnitude w ith the experimental one. [S0163-1829(98)08941-3].