Vortex Dynamics in Bulk High Temperature Superconductors Estimated by Microwave Absorption

Vortex dynamics was investigated by the transient modulated microwave absorption after the field sweep stop and the field reversal on the weak- and strong-link granular YBCO. There are differences among the static, quasi-static and dynamic transient flux distributions. The fluctuating signal caused by a flux jump was first observed in Bi2212. The time constants of these vortex dynamics were estimated.