Alcator C-MOD toroidal field magnet assembly

The Alcator C-MOD toroidal field magnet is a cryocooled copper magnet incorporating several unique design features. Each rectangular magnet turn comprises four separate components, inner and outer vertical legs and upper and lower radial arms. The inner vertical legs of the magnet are bonded together into a wedged self-supporting unit. The radial arms and outer vertical legs carry the magnetic loads to an external superstructure against which the toroidal magnet forces are reacted. Although the superstructure is a massive structure (up to 0.66 m thick), these forces cause substantial deflection of the superstructure, resulting in several millimeters of motion at the connection between the parts of each turn. The electrical connections at each corner of the magnet are made with sliding joints utilizing silver-plated felted and sintered copper pads. These sliding electrical contacts carry the full toroidal field magnet current of 0.26 MA. The manufacturing processes for the various magnet components are outlined, and the assembly of the toroidal field magnet components into the tokamak is described