Modeling and Numerical Simulation for a Spherical Vector-Potential Coil

We proposed a model for a spherical vector-potential coil and investigated the properties of the coil, including the uniform distribution of the vector potential. We modeled a structure in which thin toroidal coils are superposed along a spherical surface. Rather than arranging the toroidal coils in close contact with each other along the surface of the sphere, the layer spacing of the toroidal coils should be constant so that the projection onto the axis of the sphere is equally spaced. When a current was applied to a toroidal coil, no magnetic field was created outside the toroidal coils; instead, a vector potential was present. When the same current was passed through each toroidal coil, the vector potential in the sphere achieved a uniform distribution by superposition. We presented the results of our numerical simulation of the distribution of the vector potential and the induced voltage when a secondary conductor was passed through the coil.