| 摘要 |
<p>A mass analyser is provided comprising an ion guide 2 comprising a plurality of electrodes having apertures through which ions are transmitted in use. A plurality of pseudo-potential barriers, wells or corrugations are created along the axis of the mass analyzer 2. The amplitude or depth of the pseudopotential wells, corrugations or barriers is inversely proportional to the mass-to-charge ratio of an ion. One or more transient DC voltages or voltage waveforms are also applied to the electrodes of the mass analyser 2 in order to urge ions along its length. The amplitude of the transient DC voltages applied to the electrodes is increased with time and ions are caused to be emitted from the mass analyser 2 in reverse order of their mass to charge ratio. Two AC or RF voltages are applied to the electrodes. The first AC or RF voltage is arranged to provide optimal pseudo-potential corrugations, barriers or wells, whilst the second AC or RF voltage is arranged to provide optimal radial confinement of ions within the mass analyzer 2.</p> |
