AC losses in superconducting Nb{sub 3}Sn and NbTi CIC conductors

Journal Article · Mon Jul 01 04:00:00 EDT 1996 · IEEE Transactions on Magnetics

DOI:https://doi.org/10.1109/20.511465· OSTI ID:287719

Oliva, A B ^[1]; Baudouy, B J.P.; Miller, J; Van Sciver, S W ^[2]

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1. Ansaldo Energia, Genova (Italy)
2. Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Lab.

AC losses measurements and calculation on large scale Cable-in-Conduit (CIC) conductors have been carried out at NHMFL. In particular samples of the Nb{sub 3}Sn and NbTi conductors developed for the NHMFL 45-T Hybrid Magnet superconducting outsert have been tested. A calorimetric technique involving superfluid helium (He II) has been used. The samples have been tested with applied field variation rates varying in the range between 0.01 T/s to 30 T/s. From results it appears that for most of the samples, at high field variation rates, the coupling currents are so intense to locally saturate the superconducting strands. As no theories describing the saturation regime in CIC conductors exist, the authors tried to extend the theories developed for monolithic conductors to the more complicated CICC geometry. It emerges by defining an effective coupling time constant and an effective radius for the conductor that it is possible to fit the data with good accuracy. Effective coupling time constant and an effective radius for the conductor that it is possible to fit the data with good accuracy. Effective coupling time constants between 3 ms and 200 ms, depending on the strands surface condition and the cable void fraction, have been measured for the Nb{sub 3}Sn conductors, while a time constant of 16 ms has been determined for the NbTi sample. The experimental results and the theoretical analysis are reported in the paper.

• OSTI ID: 287719
• Report Number(s): CONF-950691--
• Journal Information: IEEE Transactions on Magnetics, Journal Name: IEEE Transactions on Magnetics Journal Issue: 4Pt1 Vol. 32; ISSN IEMGAQ; ISSN 0018-9464
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
AC LOSSES
CALORIMETRY
DESIGN
ELECTRIC CONDUCTORS
EXPERIMENTAL DATA
NIOBIUM ALLOYS
SUPERCONDUCTING CABLES
SUPERCONDUCTING COMPOSITES
SUPERCONDUCTING MAGNETS
THEORETICAL DATA
TIN ALLOYS
TITANIUM ALLOYS