Patent ID: 9184039
Filing Date: 2015-11-10
Classification: H01J

Abstract:
1. A mass analyser comprising: an ion guide comprising a plurality of electrodes having apertures through which ions are transmitted in use; an AC or RF voltage applied to at least some of said plurality of electrodes such that, in use, a plurality of axial time averaged or pseudo-potential barriers, corrugations or wells are created along at least a portion of the axial length of said ion guide; and one or more transient DC voltages or potentials or DC voltages or potential waveforms applied to at least some of said plurality of electrodes for driving or urging ions along or through at least a portion of the axial length of said ion guide so that in a mode of operation ions having mass to charge ratios within a first range exit said ion guide whilst ions having mass to charge ratios within a second different range are axially trapped or confined within said ion guide by said plurality of axial time averaged or pseudo-potential barriers, corrugations or wells.