Design of a full-scale magneplane vehicle

The design of a full-scale 140-passenger Magneplane vehicle is described, emphasizing its cryogenic aspects. The vehicle has an overall length of 50m and maximum width of 3.8m. Its gross weight is just under 45,000 kg. The cross-sectional profile and structure of the fuselage are modeled after modern commercial Jet aircraft such as the Boeing 707. Sixteen elliptic superconducting pancake coils are placed in the bottom 120° arc of the vehicle with a center-to-center spacing of 2.75m. With all coils energized at 1.25×10⁶A-turns each, a lift force of 5×10⁵N will be produced at high speeds for a separation distance of 25cm between the surfaces of the coils and the levitation strips. A hollow conductor is proposed for the superconducting coils. It is a niobium-titanium multifilament, aluminum stabilized and stainless-steel reinforced composite with a rectangular cross-section, having overall dimensions of 2.5cm by 1.25cm, with an equivalent 1-cm diameter hole. Supercritical helium is circulated through the coils to keep them in a cryogenically stable condition. Each coil is enclosed in its own vacuum envelope together with its thermal shield, persistent switch and necessary structural support. The coolant passes continuously through hollow passages in a number of parallel paths, maintaining a set temperature. The stability of the conductor during its normal excursion has been analyzed to choose a coolant flow rate which allows a certain portion of the coil to become resistive, and remain so for a limited duration of time, without forcing the entire coil to quench. The behavior of the normal-zone propagation as a function of coolant flow rate, as well as pressure drop and frictional heat generation through the conductor, have been studied for the present geometry.