On the Dipole-Induced Resonance Motion in a Paul Trap

The problem of resonant motion induced by the dipole component of the antisymmetric potential function in a radiofrequency Paul trap is investigated here. We show that, at low-level additional rf-voltage, the line-shape and the increasing rate of its amplitude, for the ion-excitation phenomenon, can be derived from the dipole approximation of the antisymmetric term in the potential energy. This approximation does not take into account the observed line-shift.