Confinement and related transport in Extrap geometry

The properties of the plasma equilibrium are investigated for the Extrap magnetic confinement geometry. An analytical solution for the profiles of the plasma parameters are found under the assumption that the energy is lost primarily in the radical direction by heat conduction and convection. An estimate of the radial particle confinement time is given, showing favorable scaling with plasma density and temperature. The conventional assumption of a uniform current density is shown to be unjustified in the case of an inhomogeneus electron temperature. An analytical expression is found for the pinch radius at different mechanisms of the heat transport. (author)