EPOXY-RESIN DEVELOPMENTS FOR LARGE SUPERCONDUCTING MAGNETS IMPREGNATION

The future detectors ATLAS and CMS of the Large Hadron Collider at CER N will use two huge superconducting magnets. Both are now under design , and their electrical insulation could be realized using epoxy resin and a wet impregnation technique. Because of their large dimensions, a nd the indirect cooling of the superconductor, the strengths of the re sin and of the resin/conductor interface are of major importance. A ne w generation of epoxy resins for vacuum/pressure impregnation methods has been tested, and compared with some classical and well-known epoxy resins used in impregnation techniques. In order to understand the me chanical behaviour at 4 K, the complete evolution from liquid state to low temperature service condition is considered. The paper will prese nt some results on the mechanical properties, the density and the chem ical shrinkage occurring during the polymerization and the thermal con traction between room temperature and 4 K for these different types of epoxy resins. (C) 1998 Elsevier Science Ltd. All rights reserved.