Characterization and Qualification of Cyanate Ester/Epoxy Insulation for NSTX-U Fusion Magnets

In recent years, CTD has pioneered the development of radiation-resistant, cyanate ester-based resins suitable for insulating superconducting and normal magnets for fusion energy applications. These materials have been shown to exhibit very good radiation resistance, excellent mechanical properties, and good processing characteristics. More recently, a cyanate ester/epoxy formulation was qualified for use in constructing the ITER Toroidal Field coils. This product, designated CTD-425, has also been selected for use in upgrading the center stack for the National Spherical Torus Experiment (NSTX), in building the correction magnets for the Wendelstein 7-X stellarator in Germany, and is under consideration for use in the upgrade to MAST being constructed in the UK. CTD has worked closely with the Princeton Plasma Physics Laboratory and others to qualify the CTD-425 for these new applications. This paper will discuss the test methods and test philosophy used to qualify CTD-425 for use in NSTX and how this qualification procedure can be useful for future fusion and other magnet systems.