Stability of Al-stabilized conductors for LHC detector magnets

The magnets actually under design for the Large Hadron Collider detectors at CERN, ATLAS and CMS, are based on Al stabilized conductors. The windings of these magnets are big structures epoxy impregnated and indirectly cooled by two-phase LHe. Energy releases due to epoxy cracking or to friction between cables could quench the whole magnet. In order to prevent this occurrence, the stability against thermal disturbances must be carefully studied. This paper deals with the development of numerical codes which are able to calculate the recovery or the propagation of a 3D normal zone in a nonhomogeneous and anisotropic medium. Three different numerical codes are described. The codes were tested through the comparison of their prediction with the measurements of the minimum energy required to have a quench propagation on the mock-up of the DELPHI magnet at Rutherford Laboratory.<
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