Abstract
The influence of the flux flow on a.c. loss and magnetic penetration process in superconductors has been investigated. Asymptotic solutions of magnetic and electric fields and a.c. loss are presented in the form of a power series of [Lambda], the normalized frequency of the external a.c. magnetic field. The results show that the flux flow retards the response of inner magnetic field to the external one, which results in a deviation from the critical state model and a non-hysteretic loss. In the cases of H0>Hp, the deviation from the critical state is in the order of the second power of [Lambda]. The induced electric field and the macro-penetration depth are decreased by the slowdown of the flux movement, giving a negative contribution to the a.c. loss. However, the negative contribution is compensated by the increase of the current density, leading to a net increase of the a.c. loss. As a result, the a.c. loss exhibits a positive dependence on the frequency and the amplitude of the external magnetic field.