Production and qualification of the 60-kA, aluminum-stabilized conductor for the ATLAS B0 coil

Abstract

For the toroidal ATLAS magnet system, some 90 km of aluminum stabilized conductor are required. The conductor is a Rutherford cable, coextruded with very pure aluminum. The main characteristics of the conductor are: (1) a very large $9 critical current, 60 kA at 5 T and 4.2 K; (2) RRR of the stabilizing aluminum of at least 1000 on the finished conductor; (3) a good bonding between the Rutherford cable and the stabilizer: a shear stress of 20 MPa is required; and$9 (4) 1750 m of unit length. To assure a good quality of the conductor all along the production and to minimize the risk of rejection of such expensive units, a strict quality assurance was established. The paper describes the results 9 of the R&D phase to set all parameters to produce the first two unit lengths necessary for the winding of the B0 coil (a 9 m long model coil of the ATLAS Barrel Toroid). It also describes the control system based on continuous 9 ultrasonic inspection, able to provide images of the cable inside the aluminum that is used to evaluate on line the quality of aluminum to cable bonding. (11 refs)