Geometry optimisation of a transparent axisymmetric ion trap for the MORA project M. Benali, G. Quéméner, P. Delahaye, X. Fléchard, E. Liénard and B. M. Retailleau Eur. Phys. J. A, 56 6 (2020) 163 Published online: 05 June 2020 DOI: 10.1140/epja/s10050-020-00168-y