Magnetization AC losses of stacks of YBCO coated conductors

This paper presents a study of the magnetization AC loss characteristics of YBCO coated conductors arranged in vertical stacks, which is a common configuration in practical applications such as superconducting coils. The AC losses in applied external perpendicular field are investigated both experimentally and by means of finite-element method calculations. The numerical method is validated by comparison with experimental results, and is also used for calculation of the losses in cases for which our present experimental setup is not suitable due to physical constraints. It is shown that increasing the number of tapes in the stack leads to a decrease of the magnetization AC loss. The inter-tape spacing has been also varied in order to investigate its influence on the AC loss performance of the YBCO stacks. The calculated magnetic field and current density profiles are used to illustrate the loss differences in the various cases.