Stability Problem in 3D Multipole Ion Traps

We suggest a concept of ion trapping in three-dimensional multipole electric fields. In this work, we propose a vibromechanical interpretation of an ion localization stability problem in a three-dimensional octupole radio-frequency electric fields and have made a transition to an equivalent autonomous dynamical system. The conditions for stable ion localization in three-dimensional octupole trap in radio -frequency-only-mode and mixed-mode are determined. The ion's effective potential for the mixed-mode is calculated and the coordinates of the stable quasi-equilibrium points are obtained. The sensitivity of the effective potential configuration to the polarity of the DC component is estimated. The ion's dynamics in an original and autonomous systems is considered, and a method for optimizing the shape of trap's electrodes is proposed. (c) 2022 Elsevier B.V. All rights reserved.