AN ION FOCUSSING AND CONVEYING DEVICE AND A METHOD OF FOCUSSING AND CONVEYING IONS

摘要

An ion focussing and conveying device (10) comprises a plurality of electrodes (12) in series. Means is provided to apply a first alternating voltage waveform to each electrode (12), the phase of the alternating voltage in the first waveform is applied to each electrode (12) in the series being ahead of the phase of the first alternating voltage waveform applied to the preceding electrode (12) in the series by less than 180 DEG , preferably by 90 DEG or less, such that ions are focussed onto an axis of travel and impelled along the series of electrodes (12).