1992 Volume 68 Issue 6 Pages 600-615
It is shown that the plasma equilibrium equation of Grad-Shafranov type is obtained in the system with a closed helical magnetic axis, however only when its torsion is kept constant along the axis. The simple analytical solution of the equation is derived and the method for high beta plama confinement is suggested. The solution is compared with that of a tokamak system in order to clarify the characteristic feature of the system with a helical magnetic axis.