Nitrogen transport in ASDEX Upgrade: Role of surface roughness and transport to the main wall

•The transport and deposition of nitrogen in ASDEX Upgrade was studied by the injection of 15N and ion beam analysis of exposed samples.•The N deposition on rough surfaces is increased due to co-deposition of N with other impurities.•The 15N deposition on a sample exposed at the outer midplane is only 2–3 times smaller than the deposition on samples exposed to the divertor plasma.•WallDYN simulations predict N areal densities which are by a factor of 4–20 higher than the ones observed in the experiment.