ABSTRACT
This chapter provides certain results of analytical theory of equilibrium of toroidal systems without axial symmetry. It considers the systems with a spatial magnetic axis and longitudinally homogeneous magnetic field along this axis. The chapter presents an explicit form of the metric tensor of the helical column of circular cross-section with a low- and a finite-pressure plasma. It analyses the helical column at a highplasma pressure and explain how the results concerning the tokamak equilibrium should be formally replaced to obtain similar results for helical equilibrium. The chapter shows the presence of finite-pressure plasma effects competing with the vacuum magnetic hill. It also considers confinement systems with a helical magnetic axis. The chapter suggests that in the absence of a longitudinal current and in the limit of negligibly low plasma pressure the magnetic well is negative, which corresponds to the magnetic hill.
