Interaction between fast particles and turbulence

A systematic study of high energetic alpha particle interaction with microinstability driven turbulence (ITG) is presented. The alpha particles are considered to be passive, thus not modifying the fine structure of the turbulence, and modelled as Maxwellian distributed. Both the turbulent fields and the evolution of the alpha distribution are computed by means of an Eulerian, flux tube code. It is shown how significant transport of high pressure distributions can occur, and how the direction and the intensity of the particle flux is sensitive to the choice of the temperature scale length of the alpha distribution, due to thermodiffusive phenomena. The diffusivity of an ITER-like case is studied, starting from an analytical treatment of the density and temperature profiles, which we show to be significant. New interpretative tools, by means of a single particle following code, are also presented. © 2008 American Institute of Physics.