抄録
The force-free magnetic field equation ∇×B=αB has been solved analytically in a toroidal coordinates system for the axisymmetric torus which is antisymmetric with respect to equatorial plane without the approximation of large aspect ratios. A set of fundamental solutions are presented each of which asymptotically approaches that for the cylindrical configuration when the aspect ratio goes to infinity. With this set of fundamental solutions, the eigenvalues of the force-free magnetic field are calculated for tori of circular and elliptical cross-section. It has been shown that the antisymmetric eigenvalue increases with decreasing aspect ratio.
