It was recalled that a risk of overheating arose if the stability of an MgB2 coil was lost. This was due mainly to the low thermal conductivity of the matrix metal, which was typically Fe or Ni. Due to a strong chemical reaction, Cu could be used in contact with MgB2 only in specific cases: in situ preparation, and low formation temperature. However, recent developments in the manufacture of MgB2 conductors had resulted in stabilized MgB2 tapes. A computational study was made of the stability of a MgB2/Ni/Fe/Cu tape. Firstly, the effective material properties of the tape were computed. Based upon these material properties, the basic quenching characteristics (minimum propagation zone, minimum quench energy and normal zone propagation velocities) were calculated for tapes at 15, 20 and 25K. The tape unit cell model was used in the calculations. The computed stability results were compared with measured data for a monofilamentary MgB2/Cu/Ni tape and commercial LTS and HTS. According to the results, the basic computed quenching characteristics were between those of LTS and HTS materials.

Stability Considerations of Multifilamentary MgB2 Tape. A.Stenvall, A.Korpela, R.Mikkonen, G.Grasso: Superconductor Science and Technology, 2006, 19, 184-9