Weibull statistical analysis of quench current of ac superconducting wires and coils

Quench of superconducting wires can be regarded as probabilistic phenomena due to local instability in the wire. This paper describes statistical scattering in quench current of a.c. superconducting wires and coils using Weibull statistics. Experimental results revealed that, in some cases, the scattering was expressed by mixed Weibull distribution with different shape parameters. These results suggested that there could exist not only intrinsic instabilities with small scattering in quench current, but also other kinds of weak points with large scattering. Probabilistic aspect of quench was also verified and localized and precursory quench phenomena observed. (C) 1997 Elsevier Science Limited.