Anderson's Flux Creep Model and Irreversibility Lines in Superconductors

Based on Anderson's flux creep model, the process of flux relaxation in superconductors is analyzed in this paper.It is found that the transition of magnetic reversible property to magnetic irreversibility in superconductors can be predicted when the ratio of pining potential to thermal excitation energy decreases to a certain value.The irreversibility line correlates to the disappearance of critical state in superconductors.