Stability of Superconductor

Magnesium diboride, MgB₂ is a tempting superconducting material in real technical applications due to its relatively simple structure and high critical temperature. It is widely believed that MgB ₂ conductors could deliver the wire performance required for applications operating at 20-30 K in the $1 to $3 per kA-m range in the near future. The material is suitable especially at low field DC applications such as MRI devices and induction heaters. However, the critical current determination of MgB₂ coils is challenging. This is due to the fact that most conductors include ferromagnetic constituents in matrix metal and therefore computing a so called engineering permeability is necessary. In addition the electromagnetic behavior can be either isotropic or anisotropic depending on the conductor configuration. In this paper the anisotropic engineering permeability is studied in detail and quench is analyzed in three MgB ₂ model solenoids