Impurity Transport in Cylindrical Plasmas

A 1-D plasma transport code for cylindrical geometries is presented. The code is particularly well suited for configurations where magnetic flux surfaces are in rapid motion as in conducting liner experiments. A multi-species flux plasma model is derived, and, in particular, the cross magnetic field drifts of high Z impurity ions are considered. The code is based on a finite difference scheme involving numerical Lagrangian cells that move with the E X B drift velocity. The motion of the cells is determined by the pressure balance requirement. In each time step dissipative effects are considered separately, so that the pressure adjustment can be treated as an ideal adiabatic process. Test run results of the ideal adiabatic compression of a plasma by an infinitely conducting liner are given to show the effectiveness of the pressure adjustment algorithm. The effects of classical transport have been included in a test run of the evolution of a Tokamak type plasma with PLT parameters. A modest penetration of iron ions toward the center of the plasma column is found. An algorithm for neutral particle streaming into the plasma from the wall is described. (Author)