title: Flux avalanche in a superconducting film with non-uniform critical current density.
abstract: The flux avalanche in type-II superconducting thin film is numerically simulated in this paper. We mainly consider the effect of non-uniform critical current density on the thermomagnetic stability. The nonlinear electromagnetic constitutive relation of the superconductor is adopted. Then, Maxwell's equations and heat diffusion equation are numerically solved by the fast Fourier transform technique. We find that the non-uniform critical current density can remarkably affect the behaviour of the flux avalanche. The external magnetic field ramp rate and the environmental temperature have been taken into account. The results are compared with a film with uniform critical current density. The flux avalanche first appears at the interface where the critical current density is discontinuous. Under the same environmental temperature or magnetic field, the flux avalanche occurs more easily for the film with the non-uniform critical current density. The avalanche structure is a finger-like pattern rather than a dendritic structure at low environmental temperatures.
authors.affiliation: Key Laboratory of Mechanics on Disaster and Environment in Western China, Ministry of Education of China, Lanzhou, Gansu 730000, People's Republic of China; Department of Mechanics and Engineering Sciences, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China.
authors.forename: Yurong
authors.initials: Y
authors.lastname: Lu
authors.affiliation: School of Mechano-Electronic Engineering , Xidian University , Xi'an, Shaanxi 710071 , People's Republic of China.
authors.forename: Ze
authors.initials: Z
authors.lastname: Jing
authors.affiliation: Key Laboratory of Mechanics on Disaster and Environment in Western China, Ministry of Education of China, Lanzhou, Gansu 730000, People's Republic of China; Department of Mechanics and Engineering Sciences, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China.
authors.forename: Huadong
authors.identifier: 0000-0002-0304-3191
authors.initials: H
authors.lastname: Yong
authors.affiliation: Key Laboratory of Mechanics on Disaster and Environment in Western China, Ministry of Education of China, Lanzhou, Gansu 730000, People's Republic of China; Department of Mechanics and Engineering Sciences, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China.
authors.forename: Youhe
authors.initials: Y
authors.lastname: Zhou
keywords: critical current density; flux avalanche; magnetic field ramp rate; superconducting film