Effect of Local Defects on HTS Fusion Magnets Performance

Local defects in the manufacturing of high temperature superconducting cable-in-conduit conductors are known to be present at different stages of the conductor production. The impact of such defects on the performance of one module of the hybrid option of the EU DEMO Central Solenoid is investigated here using the H4C code. For such analysis, the modeling of each strand is needed, since the defect leads to a strong nonuniformity of the current distribution in the conductor cross section, which in turn causes temperature differences in the cross section during the propagation of a quench. The analysis allows to assess the level of damage in strand(s) before inducing a quench. In case a quench is initiated, the model is used to follow its propagation to assess the hotspot temperature. It is also observed that a quench is induced in the low temperature superconducting third layer starting from a quench initiated in the first layer, via interlayer thermal coupling.