poloidalfield
Poloidal field refers to that portion of a magnetic field whose lines lie in meridional planes of a roughly spherical geometry, i.e., in the radial and polar (r and θ) directions. It is contrasted with the toroidal component, whose lines encircle the axis in the azimuthal (φ) direction. In many contexts the field is described by a poloidal–toroidal decomposition, B = B_p + B_t, where B_p carries the radial and latitudinal components.
In solar and planetary dynamos, the poloidal field plays a central role. The solar magnetic cycle involves
In fusion devices such as tokamaks, the poloidal field is essential for confinement. The toroidal field, produced
Mathematically, poloidal and toroidal fields can be described by a poloidal–toroidal decomposition, B = ∇ × ∇ × (P