Crossed fields magnetization of YBCO single-grain bulk superconductors

Abstract

Operando magnetization remains a critical issue for practical applications of single-grain bulk high temperature superconductors (HTSs) as strong trapped field magnets (TFMs). It has been previously proved that the magnetization efficiency can be improved by exploiting flux jumps during the pulsed field magnetization (PFM). In this study, we proposed a novel PFM sequence combining a transverse magnetization followed by a vertical magnetization namely the crossed fields magnetization. It was found the final trapped field distribution greatly depended on the direction of the transverse field exhibiting chirality features. Numerical simulation revealed the redistribution of the induced current during the vertical PFM indicating more intense flux motion will be involved. As a result, the external magnetic field required to magnetize the bulk was reduced by about 10 % at 30 K and the magnetization efficiency was improved.