A simple explanation is given as follows. Once inside the quadruple, the ions oscillate in the (x), and (y) dimensions as a result of the high-frequency electric field.
A simple explanation is given as follows. Once inside the quadruple, the ions oscillate in the (x), and (y) dimensions as a result of the high-frequency electric field.

Figure 25. The Quadrapole Mass Spectrometer
The stability of the oscillating ions are determined by the magnitude of two parameters (a) and (q) which are defined by the following equations:
