Dielectric, thermal and mechanical properties of insulation systems for quench heaters for the protection of superconducting magnets

Abstract High dielectric strength, low thermal resistance and mechanical robustness are conflicting requirements on the insulation system between the superconductors in magnet coils and the quench heaters placed on the coil for active protection in case of a quench. To investigate possibilities to further improve the performance of quench heaters for future superconducting magnets, we have characterised polyimide, PEEK and fibre reinforced PEEK films that can be used to produce large flexibly quench heater circuits. The dielectric strength (at RT and at 77K), low temperature thermal conductivity, tensile strength (at RT and at 77K) and the force needed to puncture the different materials are compared.