Use of superconductors with varied characteristics for optimized design of large-bore High-field magnets

An iterative design procedure for optimum placement of vapor-deposited Nb3Sn ribbon superconductors in high-field large-bore modular magnets is described. The mechanical strength, current-carrying capabilities, and electromagnetic stability of the ribbons are independently adjustable to produce the various conductors required. An existing 8.4-cm-bore 8-tesla magnet is used to illustrate a modular-type construction. Use of the iterative process to satisfy sometimes conflicting mechanical, electromagnetic, and cryogenic requirements is detailed in a review of the design of a 15-cm-bore 15-tesla superconductive magnet which is now under construction.