Improved experimental set-up for calorimetric AC loss measurements on HTSs carrying transport currents in applied magnetic fields at variable temperatures

To utilise an high-temperature superconductor (HTS) in an electro-technical device, an optimal operating current and an optimal operating temperature need to be determined. For this purpose the AC losses should be measured under application-like conditions. To perform such measurements we have designed and constructed a calorimetric measuring system which now has been in operation for a few years. During this time the system has gradually been improved. In this paper we describe the system in its present state and discuss the technical improvements in detail. The improvements include the possibility to inject a transport current and to apply a magnetic field in any direction perpendicular to the current path. Is addition the measurement of the AC losses is averaged over the sample length. Experimental results of the AC losses due to combinations of transport currents and magnetic fields in different orientations at various temperatures are presented for two BSCCO/Ag tapes. (C) 2001 Elsevier Science B.V. All rights reserved.