Proton distribution function as a function of radius at 100 TeV (blue-dashed line) and 1 PeV (red-solid line). The dash-dotted vertical line marks the superbubble radius, which separates the low-diffusion and interstellar-medium diffusion zones. The solid vertical lines indicate the positions of molecular clouds in the model. The relative normalisation between the two displayed proton distributions changes strongly at small radii, which results in energy dependent morphology (see Fig. 9).