TWO-DIMENSIONAL ION TRAP WITH RAMPED AXIAL POTENTIALS

摘要

The invention provides a two-dimensional ion trap (200), comprising a plurality of elongate electrodes (220, 225, 230, 235) positione between first and second end electrodes (210, 215), the plurality of electrodes and first and second end electrodes defining a trapping volume A controller (270) in electrical communication with the plurality of elongate electrodes (220, 225, 230, 235) and the first and second end electrodes (210, 215) is configured to progressively vary a periodic voltage applied to at least one of the plurality of elongate electrodes (220, 225, 230, 235) to cause ions to be radially ejected from the ion trap (200) in order of their mass to charge ratios Concurrently, the controller (270) is configured to progressively vary a DC offset of least one of the first and second end electrodes (210, 215) with respect to the plurality of elongate electrodes (220, 225, 230, 235).