3D magnetic optimization of dipole ends with rectangular cross-sections Etienne Rochepault, Guy Aubert, Pierre Vedrine and Frédéric Bouillault Eur. Phys. J. Appl. Phys., 64 2 (2013) 24507 Published online: 08 November 2013 DOI: 10.1051/epjap/2013120414