Forms and oscillations modes of ion cloud in the linear RF-only quadrupole traps and in ion traps

Computer modelling of space configurations of ion clouds consisting of different m/z ions and dynamics of their motion in the presence of external (dipolar and quadrupolar) RF-field were analyzed. Forms of ion clouds in ion traps were obtained by molecular modelling. It was shown that stratification of different m/z ions appears as a result of interaction of ion clouds with RF fields and with each other. For ions with high charge q=30 eelectron and mass m=30 000 mproton (electrosprayed protein ions in ion guides and ion traps) at ion densities ∼108 cm-3 stratification takes place even at room temperatures. Coalescence of ion resonance frequencies for light and heavy equally charged ions in Paul ion trap was also demonstrated