ATLAS End Cap Toroid Final Integration, Test and Installation

The ATLAS Experiment at LHC, CERN will utilize a large, superconducting, air-cored toroidal magnet system with a long Barrel Toroid and two End Cap Toroids. Each End Cap Toroid contains eight racetrack coils mounted as a single cold mass in a cryostat vessel of approximately 10 m diameter and 5 m length. The operating current is 20.5 kA at 0.25 GJ stored energy and a peak field of 4.1 T in the windings. This paper presents the status of the End Cap Toroid Project. Final integration of the two cold masses, 120 tons each, into their respective vacuum cryostats is described. The specialized techniques, procedures and tooling infrastructure required for these operations are explained. Pre-installation cooldown to 85 K is reported. Installation of the toroids in the ATLAS cavern 100 m underground will be described. The final interfacing to the Barrel Toroid and services in the cavern will be reviewed along with preparations for final test and commissioning.