High-Shear-Strength, Radiation-Resistant Electrical Insulations for Plasma Confinement Magnets

The United States Department of Energy is developing several devices to advance the development of fusion energy. Plans for future major fusion machines will undoubtedly utilize superconducting magnets which operate at 4K or below. Magnets for smaller fusion research devices may also be built using normal copper conductor magnets that operate at temperatures up to 422 K (150C). The availability of electrical insulations with higher shear strengths and radiation resistance, and the ability to operate at extreme temperatures will be critical in achieving this goal. High-strength electrical insulations will be developed to address the needs of future fusion energy devices. These insulators will be designed to provide high mechanical strength and radiation resistance, and will be compatible with state-of-the-art magnet fabrication processes. In Phase I the addition of polyimide to cyanate ester-epoxy blended resin showed improved shear properties as well as reduced heat of reaction (energy released) during the curing of the material. In addition, nanomaterial fabric treatments were used to improve the shear fatigue performance of composites made with these resins. The Phase II effort will continue to improve and optimize the performance of these resins and the application of nanomaterial fabric treatments for use with resins for VPI processing, as well as to explore their application to ceramic/polymer hybrid insulation system and for insulating coatings for high temperature superconducting materials and tapes. Commercial Applications and Other Benefits: In addition to providing improved products for use in the construction of fusion magnets, the advanced electrical insulations to be produced in this will likely also used be used in medical devices such as cancer therapy and imaging systems, high-field accelerator magnets, and motors and generators that operate under extreme conditions.