Molecular-dynamics simulations of cold single-species and multispecies ion ensembles in a linear Paul trap

The properties of cold ion plasmas with large numbers (>200) of laser- and sympathetically cooled species are modeled in detail using molecular dynamics simulations. We describe how to extract temperatures and ion numbers from CCD images. The identification of the ion species by excitation of their oscillation modes is discussed. The sympathetic cooling efficiency, effects of the rf micromotion and of collision heating by a neutral background gas are analyzed, in part experimentally.