Analysis on magnetic torque of superconducting sphere with high rotating speed in uniform magnetic field

On the basis of the classic electromagnetic field theory and London equations, a calculation model was founded for the magnetic torque of a superconducting sphere with high rotating speed in a uniform magnetic field. By taking account of the interaction of the London moment produced by the rotating superconducting sphere with the applied magnetic field, calculation method of the magnetic torque was derived from the magnetic induction expressed in terms of spherical harmonic functions and the boundary condition of superconducting sphere. In addition, a calculating example is shown. The theoretical model for toque calculation is valuable for the farther research on the dynamic behavior of superconducting sphere with high rotating speed.