CONDITIONS FOR THE EXISTENCE OF STEADY-STATE STELLARATORS

Low collisonality methods developed earlier [Phys. Plasmas 1, 394 2 (1 994)] are extended and applied to the characterization of steady state , toroidally confined non-symmetric plasmas. A magnetic field is assum ed which is a small perurbation of one with exact magnetic surfaces an d zero shear. However, exact magnetic surfaces are not required. Two t ypes of conditions on the system are found. In analogy with tokamaks, conditions of energy flux balance and particle flux balance are obtain ed. The fluxes are of magnitude comparable with those in a tokamak. An other class of constraints relates to properties of the magnetic field B. In addition to the condition of very small shear [Phys. Plasmas 2, 3595 (1995)] and the condition that on a flux surface Sigma\B.del B\( -1) be a function of B [Phys. Plasmas 4, 575 (1997)], as extended, a h ierarchy of increasingly restrictive conditions on B are found. The co nsequence of these constraints is explored very briefly. (C) 1998 Amer ican Institute of Physics.