This engineering diagram shows the Alcator C-Mod tokamak. From the center outward: The toroidal plama (light orange) is inside the vacuum chamber (light grey). Magnetic coils surround the chamber (red, brown, green) providing the magnetic field. The magnets are encased in a strong Inconel superstructure ( Inside the Inconel structure light grey cylinder, purple bolts, blue). The entire structure is supported on three posts (orange) and encased in a cryostat (clear) and a concrete radiation igloo (clear).