Coupling of helium and impurities to the H/D background in magnetically confined plasmas

Alpha particles and impurity ions are coupled to the hydrogen/deuterium background plasma via charge exchange processes. The corresponding change of the charge state distribution of the "radiating test particle" is identified to be of similar nature like the particle transport. Traditional analysis in terms of diffusion and convection coefficients (D, V) is therefore difficult to interpret as the neutral density distribution is not well known, charge exchange processes are treated as a free parameters and excited state contributions are diverging. A self-consistent excited states coupling approach (SCESCA) of impurity and plasma background atomic kinetics is proposed which removes these difficulties. SCESCA provides an ideal basis for a pure diffusion analysis in space which is requested to test global effects of turbulent transport theories. Simulations for argon and helium are carried out which are contrasted to the data.