[WBP2] Bulk, Assembled Conductors, AC Loss

[WBP2-22] Sensitive Measurement of AC Loss Characteristics of Short Straight HTS Tapes by Reducing Background Losses in the Pickup Coil Method

*SHUMA Kawabata¹ (1. Kagoshima University (Japan))

Keywords:

HTS,AC Loss Measurement,Measurement Sensitivity

For practical applications such as power cables and transformers using high temperature superconducting (HTS) tapes, it is necessary to reduce the losses of HTS tapes. We have investigated the reduction of background loss, which is the apparent loss that occurs even where there is no specimen in the pickup coil, in order to improve the sensitivity of the AC loss measurement for HTS tapes using the pickup coil method. The purpose of this study is to quantify the relationship between the parameters of the pickup coil pair and the background loss for high sensitivity measurements of the AC loss characteristics of short straight HTS tapes, and to clarify the improvement in sensitivity due to an increase in the specimen volume occupancy in the pickup coil. In this study, various pickup coil pairs symmetrically arranged in the magnet for applying the external magnetic field were fabricated according to the measurement specimen, and the effect of reducing background losses was evaluated. The high sensitivity of AC loss measurements on short straight HTS tapes due to increased specimen volume occupancy in the pickup coil was also investigated. The AC losses of Bi-2223 tape as a measurement specimen were measured with various pickup coil pairs and the background losses per unit volume of the specimen were compared. The measurement results showed that the background losses relative to the AC losses of the specimen were lowered due to the increased specimen volume occupancy in the pickup coil, and the measurement sensitivity of the AC loss improved.