Electron densities of models, with parameters as given in Table C.1. The solid, dotted and dashed black lines show the volume-averaged density for the variable B-field, the constant B-field and the K&C model, respectively. The coloured lines show the electron density for the variable B-field model at different radii. The radio electrons (at energies below the “dip”) are modelled with an energy-independent extension, therefore the density drops with radius independent of energy. On the other hand, the density of the freshly injected wind electrons decreases more rapidly for higher energies.