Charged particles in a cup-trap: trapping principles and nonlinear dynamics simulation

In the present work we consider features of localization of charged particles in a vertical linear quadrupole electrodynamic trap with a single end-cap electrode (‘cup-trap’). We qualitatively describe the end-cap field effect on the radial trapping process and numerically calculate the stability diagrams in the trap. Depending on the axial oscillations dynamic regime the shift and splitting of the stability region on the diagram have been found. The conditions of the stability diagram splitting in terms of trap and axial initial parameters have been determined.