抄録
A solution of the magnetohydrostatic problem of finding the equilibrium configuration of a plasma in a slightly bending torus tube with circular cross section is reported. Both the plasma and the tube wall are assumed to be perfectly conducting. The ratio of the tube radius to the radius of curvature, R, of the tube axis is assumed to be so small that its square is negligible. The method is an application of a perturbed cylindrical coordinate system, in which the line element ds is given by
ds2=(1−ξR−1rcosθ)2dr2+(1−ηR−1rcosθ)2r2dθ2+(1+R−1rcosθ)2dz2,
ξ and η being functions of γ satisfying ξ=d(rη)⁄dr. A result is the following. If an axially symmetric plasma cylinder with the material pressure monotonically decreasing towards the plasma surface is slightly bent into a torus, then two isobaric surfaces are closer in the more distant part from the torus axis than in the less distant part.
