Study of the Basic Properties of REBCO-coated Conductors for HTS Coil Technology

— Evaluation of Delamination Characteristics and Numerical Prediction of Flux Flow Characteristics —

Abstract

In order to operate conduction-cooled HTS coils wound with REBCO-coated conductors stably without thermal runaway, the coil should not have any degraded area in the winding, and the flux flow characteristics should be calculated numerically. However, the delamination characteristics of short wire, which are considered to be a significant factor in degradation, are inconsistent with the results of thermal stress analysis. Therefore, we newly proposed a method for evaluation of the allowable design range of the coil without degradation. This method is characterized by use of the test results of small model coils differing in the ratio of outer diameter and inner diameter. Additionally, we measured the flux flow characteristics of a dry coil and performed numerical calculation for turn-to-turn. The calculated values were in good agreement with the measured ones.