Results of AC loss tests on twisted and untwisted HTSC tape exposed to external field

• Published in: IEEE transactions on applied superconductivity Vol. 11; no. 1; pp. 2437 - 2440
• Main Authors: Hardono, T., Cook, C.D., Darmann, F.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.03.2001; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Anisotropic magnetoresistance; Applied sciences; Calorimetry; Eddy current testing; Electrical engineering. Electrical power engineering; Exact sciences and technology; Exposure; Filaments; Frequency; Joining; Loss measurement; Magnetic anisotropy; Magnetic field measurement; Magnetic losses; Materials; Mathematical analysis; Multifilamentary superconductors; Perpendicular magnetic anisotropy; Superconducting magnets; Superconducting tapes; Superconductivity; Testing
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/77.920355

This paper presents the results of magnetic loss tests on twisted and untwisted 37 multifilament tapes exposed to an alternating field at power frequencies. The losses are measured using calorimetric methods, which are capable of measuring losses in short tapes with the accuracy of several microwatts per centimeter of tape. The losses of the tape due to the longitudinal field of the untwisted tape agree well with theoretical calculations. The measurement results on the twisted filament tape, with 50-mm twist pitch, show that the losses are slightly lower than that in the untwisted tape. This is due to the reduction of the coupling losses between the filaments in the tape. It is also shown that in this presence of normal fields, the losses are about one order higher than for longitudinal fields because of the anisotropic properties of the superconducting parts and because of the existence of eddy current loss in the silver sheath.