ABSTRACT
Superconducting electromagnets are valuable for three reasons: they provide by far the highest available fields; they avoid the very heavy dissipation of conventional electromagnets; and the very high current density means that they are much smaller and lighter for a given application. An area in which superconductors have a major advantage is in the design of narrow band-pass filters on communications satellites. Filters involve complex combinations of resonant elements, and are designed on the basis that the conductors in them are perfect. Low-friction magnetic bearings involve some of the same principles as magnetic levitation of vehicles and have a number of applications in large-scale machinery and in special instruments. Superconducting magnets are featured in plans for future fusion re-actors and in magnetohydrodynamic generators attached to the hot front-ends of gas-fired power stations.
