Reduced charge state equations that describe Pfirsch Schluter impurity transport in tokamak plasma

The paper discusses the impurity transport in a tokamak in the Pfirsch Schluter regime. A reduced charge state method is developed for the set of coupled equations that describe the poloidal variation of the heat flux and the third Laguerre polynomial expansion of the distribution function. A comparison is made with analytic equations in the disparate mass limit, and the influence of the cross terms of the coupled equations, which have been neglected in earlier work, on the transport coefficients of a hydrogen helium plasma is discussed. (C) 2000 American Institute of Physics. [S1070-664X(99)03010-4].