Formulation for solving 1D minimum propagation zones in superconductors

The minimum propagation zone (MPZ) and the minimum local energy release required for a quench (MQE) are two very important parameters in superconductors targeted to coil applications. Usually, MQE is determined from MPZ. According to recent experiments, the closed-form expressions presented for these are not applicable to conductors with low n-values, e.g. BSCCO and MgB2, but a numerical model is required. When various conductor configurations are designed it is very time consuming to measure basic conductor stability parameters, such as MQE, for each conductor. This paper presents a numerical model to determine MPZs for conductors with finite n-values. Therefore, the model gives an efficient tool for conductor manufacturers to estimate what kind of disturbances their conductors can tolerate. According to the results, MQEs for the n-value 20 at the normalized operation currents of 0.5, 0.7 and 0.9 are about 25%, 60% and 100% higher than for the n-value 50.