Stability of multi-core MgB2/Ti/Cu/SS wires

Stability of 19-filaments MgB2/Ti/Cu/SS wires carrying the transport currents has been examined. Properties of two identical wires annealed at 600 °C/2.5 h and 800 °C/0.5 h were compared. It was found that annealing conditions influence not only the current carrying capacity of MgB2 filaments but also affect the inter-diffusion at Ti/Cu and Cu/SS interfaces, which is worsening the electrical and thermal conductivities of composite elements. Consequently, differences in wire’s resistances and I–V quenches were measured, which are correlating well with experimentally estimated minimum quench energy and normal zone propagation velocity.