Semi-global simulations of the magneto-rotational instability in core collapse supernovae M. Obergaulinger, P. Cerdá-Durán, E. Müller and M. A. Aloy A&A, 498 1 (2009) 241-271 Published online: 11 March 2009 DOI: 10.1051/0004-6361/200811323