Two-dimensional self-similar plasma streams with an azimuthal magnetic field

A series of two-dimensional magnetohydrodynamic equations is formulated for the expansion of a plasma stream with an azimuthal magnetic field. An explicit analytical expression is found for the case in which the adiabatic index of the plasma is gamma = 4/3. The applicability of the analytical expression to an equilibrium plasma configuration (like the tokamak) is demonstrated. 6 references