Reducing the risk of insulating magnets

Insulating magnets is often an irreversible process that occurs late in magnet fabrication after most of the capital investment has been made; if the insulation fails, the coil is scrapped. Industry experience shows that much of the risk associated with insulating magnets can be eliminated with careful selection of the insulating material, understanding how it needs to be processed, and performing a detailed design of tooling and equipment used in the insulating process. In support of these efforts many magnet designers have performed pre-coil-insulating screening test programs. These tests evaluate the performance characteristics of the insulation, define relevant processes and processing parameters for applying the insulation, and help identify important design details necessary for the coil tooling and equipment used to insulate the magnets. A review of different screening tests that have been performed in support of coil insulation efforts will be presented. This review will look at the industry experience with large and small coils, as well as research and commercial coils. Drawing from these industry experiences, suggested guidelines for the magnet designer on how to ensure the selection of the most appropriate magnet insulation material and fabrication method to minimize risk of insulation failure will be discussed.