Ion swarm data of N4+ in N2, O2 and dry air for streamer dynamics simulation A. Bekstein, M. Benhenni, M. Yousfi, O. Ducasse and O. Eichwald Eur. Phys. J. Appl. Phys., 42 1 (2008) 33-40 Published online: 28 March 2008 DOI: 10.1051/epjap:2008037