Modeling the Resistive Critical Current Transitions of Striated Superconducting Tapes

Striating a high-temperature superconducting tape into an array of narrow filaments is a viable way to reduce thermal losses in ac applications, provided the patterning process yields uniform filaments whose total critical current density scales with that of the pristine tape. To help explain some of the scaling discrepancies that are often encountered during the optimization of such a patterning step, a model was developed to calculate the expected critical current values for tapes simulated with various nonuniform critical current distributions of filaments. These results show that if the filaments are permanently damaged when their critical currents are exceeded, then a particular threshold filament can be identified whose transition to the normal state prompts a subsequent transition of all or most of the tape's remaining superconducting filaments. These critical current and threshold filament values were determined analytically for linear critical current distributions, while Monte Carlo simulations were statistically analyzed for Gaussian distributions.