STABILITY, PROTECTION AND AC LOSS OF CABLE-IN-CONDUIT CONDUCTORS - A DESIGNERS APPROACH

Stability margin, ac response (losses and current distribution) and protection issues (hot-spot temperature and maximum quench pressure) are the three primary aspects considered in the design of a superconducting magnet for application in an experimental fusion reactor. This paper reviews these three aspects in particular for cable-in-conduit conductors (CICCs). Their combination, together with the requirements on the performance of the magnet, determines a set of constraints to be satisfied at all operating points. This can be achieved only by means of compromises in the design, e.g. selecting the material fractions in the cable as a function of the specified margin and of the achievable current density. Here are presented some of the basic guidelines to be used for an effective design of a CICC, based in particular on simplified stability and hot-spot models.