Crystal magnetic structure in axisymmetric plasma accretion disks

A general class of stationary magnetic configurations which can exist in (thin) plasma accretion disks is identified by solving analytically the coupled nonlinear equations that describe the radial and the vertical equilibrium conditions of the disk. These configurations are characterized by a "crystal" structure consisting of a sequence of toroidal current filaments that can involve null points of the poloidal magnetic field. The obtained solutions are valid in the limit where the magnetic energy density is smaller than the thermal energy density (beta > 1). In view of studying magnetic disk configurations from which jets can emerge, and for which the limit where beta similar to 1 is important, the relevant equilibrium equations are derived and their symmetries are pointed out. (c) 2005 American Institute of Physics.