Ion families identified in the distribution function represented in Fig. 7. Panel a: contour lines for the core distribution in the plane identified by the radial direction, R, and the magnetic field vector. Contours have been computed after integration of the VDF along the direction perpendicular to this plane. Panels b and c refer to the proton beam and alpha populations, respectively. Solid straight line in each panel show the direction of the local magnetic field vector. The contribution from the s/c velocity has not been removed.