Composite superconductor design for large magnets

The correct specification of superconductor characteristics is of fundamental importance to the performance and optimization of a magnet. This paper presents design criteria for NbTi multifilamentary composite superconductors for large magnets. Expressions are developed relating conductor configuration to current density, magnetic field, superconductor area, temperature, thermal stability criteria, and magnet protection. Optimization of these conductor characteristics in a magnet includes consideration of current density regionalization, or grading, to minimize the required amount of superconductor without impairing performance. Standardization of conductors is proposed.