Global models for radio-frequency ion thrusters Patrick Dietz, Andreas Reeh, Konstantin Keil, Kristof Holste, Uwe Probst, Peter J. Klar and Chris Volkmar EPJ Techn Instrum, 8 1 (2021) 10 Published online: 19 July 2021 DOI: 10.1140/epjti/s40485-021-00068-5