ATLAS Barrel Toroid Warm Structure Design and Manufacturing

The ATLAS barrel toroid magnet is a large air-core toroid that provides the magnetic field needed for the ATLAS muon spectrometer. The barrel toroid structure, named warm structure, holds the eight superconducting coils evenly positioned around the beam axis with an outer diameter of 20 m. The warm structure supports not only the coils but also muon detectors, services and access for the ATLAS experiment. The warm structure withstands about 1400 tons of weight and strong magnetic forces. Physics performance of the muon detectors, and the fact that many design aspects of the toroid and of other related sub-system of the ATLAS experiment are intertwined, impose stringent requirements on the warm structure design. Extensive finite element analyses have been carried out to achieve the final design. Manufacturing feasibilities and facilities have been taken into account. This paper gives an overview on the design and manufacturing of the ATLAS Barrel Toroid Warm Structure