High stiffness fixation and thermal insulation in a superconducting planar motor

A superconducting planar motor is being investigated to provide higher acceleration potential compared to existing planar motors. Currently used permanent magnets are replaced by superconducting electromagnets, at a temperature below 20 K, providing a higher magnetic field density. Fixation of superconductors is a challenge due to the requirements on stiffness and thermal conductivity, which are conflicting in existing fixation designs. In contrast, an electromagnetic position actuator in closed loop control provides stiffness without a path for thermal conduction. The radiative heat flow through such an actuator is analyzed. Furthermore, a thin thermal insulation is required to achieve a high magnetic field density at the location of the warm motor coils. Two insulation concepts are analyzed and compared based on the remaining heat flow. First order heat transfer equations are solved and the results show the potential of the solutions proposed. Further work entails detailed design and experimental verification