Axialisation, cooling and quenching of Ba+ ions in a Penning trap Ch. Lichtenberg, G. Marx, G. Tommaseo, P. N. Ghosh and G. Werth Eur. Phys. J. D, 2 1 (1998) 29-32 Published online: 15 April 1998 DOI: 10.1007/s100530050106