Patent ID: 8907272

Claim:
An apparatus for transporting ions within a mass spectrometer comprising: a plurality of electrodes, a plurality of surfaces of which comprise a plurality of non co-planar rings defining a set of respective ion apertures whose diameters decrease from a first end to a second end along a first direction parallel to an axis of the apparatus, the set of ion apertures defining an ion channel through which the ions are transported; and a Radio Frequency (RF) power supply for providing RF voltages to the plurality of electrodes such that the RF phase applied to each electrode is different from the RF phase applied to any immediately adjacent electrodes, wherein the electrodes are disposed such that gaps are defined between each pair of successive electrodes, the gaps being oriented such that a gas flow input into the first end of the apparatus is exhausted through the gaps in one or more directions that are non-perpendicular to the axis.