Magnet insulation with resistance to high levels of radiation

Large, capital intensive magnets, superconducting or resistive, are essenti al components of fusion devices and high energy physics (HEP) accelerators. Magnets built for these applications need to be reliable, possess long mea n time between failures (MTBF), and be able to be manufactured using cost-e ffective materials and fabrication processes. Electrical insulation is ofte n the weak-link in the design of magnets, due to its sensitivity to high ra diation doses, embrittlement at cryogenic temperatures, and limitations in fabricability. Current magnet insulation materials provide sufficient electrical insulatio n, suitable mechanical properties at magnet operating temperatures, flexibl e processing for cost-effective coil fabrication and assembly, and reasonab le cost. However, they degrade to unacceptable levels of performance when e xposed to high levels of radiation. Recent work performed by CTD studied the hybridization of insulation chemis try. The goals of this work was to increase radiation resistance of the ins ulation while maintaining suitable properties and enable cost-effective pro cessing techniques. Hybrids of different organic polymers including epoxies , polyimides, bismalimides (BMIs), and other aromatic based polymers were s uccessfully demonstrated. Furthermore, hybridization of inorganic with orga nic materials was also demonstrated. The former materials are well suited f or magnets manufactured from resistive conductors or NbTi, while the latter materials are well suited for Nb,Sn and potentially HTS conductors because these materials enable a wind, insulate, and react fabrication scenario, A discussion of new hybridized radiation resistant insulation materials wil l be presented, Data will include anticipated end-of-life performance after exposure to high levels of radiation.