Copper coils Air gap Rotor aluminum (mounted to capsule) Stator iron (mounted to tube) Figure 23. Magnetic field strength inside linear induction motor 4.3.2. Tube Components (Stator) The stator is mounted to the bottom of the tube over the entire 2.5 miles (4.0 km) it takes to accelerate and decelerate between 300 and 760 mph (480 and 1,220 km). It is approximately 1.6 ft (0.5 m) wide (including the air gap) and 4.0 in. (10 cm) tall, and weighs 530 lb/ft (800 kg/m). Laid out symmetrically on each side of the rotor, its electrical configuration is 3-phase, 1 slot per pole per phase, with a variable linear pitch (1.3 ft or 0.4 m maximum). The number of turns per slot also varies along the length of the stator, allowing the inverter to operate at nearly constant phase voltage, which simplifies the power electronics design. The two halves of the stator require bracing to resist the magnetic forces of 20 lbf/ft (300N/m) that try to bring them together.