Designing, fabricating, and testing cost effective structural composite for the SSCL magnets

Particle accelerators like the Superconducting Super Collider (SSC) use superconducting dipole magnets to bend the particle bunches around the 54-mile ring and superconducting quadrupole magnets to focus the particles. The heart of these magnets is the superconducting niobium-titanium copper cable which carries extremely high current because the internal resistance is zero at liquid helium temperatures. With these high currents,the magnets generate large magnetic fields on the order of 6.7 Tesla. The superconducting cable is insulated with a wrap of polyimide film on the first layer and a second layer wrap of either a polyimide film with adhesive or a fiberglass epoxy prepreg. The insulated cable is wound into long coils and cured. All coil materials must withstand temperature extremes from 220{degree}C (428{degree}F) to {minus}269{degree}C ({minus}452{degree}F) at loads as high as 104 MPa (15 ksi). In addition, all magnet components must survive for 25 years with a total radiation dose of 1000 MRad. The parts at the end of a coil are used to support and restrain the conductors during magnet energization. The most common end part materials used to date have been G-10 and G-11 fiberglass and epoxy tubes and laminates in NEMA grades and CR type. Developments in polyimides like bismaleimides, copolymers like the newly developed PT resins and advanced epoxy blends like CTD101 and CTD102 are materials of choice for magnet components because of their radiation resistance. An extensive testing program is currently underway by the SSCL to measure the radiation degradation of these and many other materials.