Zeus Magnets Construction Status Report

Abstract

The construction progress status of the superconducting magnets for the ZEUS detector, commissioned by INFN Frascati and to be installed in the HERA e- p+ring (DESY, Hamburg), is reported. The first one is a double layer, two densities, aluminum stabilized coil 1849 mm in inner dia., 2487 mm in length and 32.6 mm thick, with a central field of 1.8 T and high particle transparency. The second one is a compensating magnet, wound by a copper stabilized Nb-Ti cable. Its coil has a central field of 5 T, inner dia. 370 mm, a length of 1200 mm and is inserted into a cold iron yoke. The main problems encountered during the large coil construction and the geometrical accuracy obtained are reported. Four splices among the high purity aluminum stabilized cable length were made. An outer support cylinder, 18 mm thick, was shrink fitted around the coil and then the temporary inner mandrel was removed. The distribution of mechanical stresses was measured in the different configurations. A large aluminum alloy vacuum chamber with high radiation transparency was built. The compensating coil is ready to be installed inside its stainless steel cryostat. The cryostat critical features are the high design pressure (20 bar) and the heavy cold mass.