An ion transport device of a mass spectrometer, comprising: a plurality of pole rods arranged in first (506B, 604B, 706B, 804B) and second rows (506A, 604A, 706A, 804A), the second row (506A, 604A, 706A, 804A) parallel to the first row (506B, 604B, 706B, 804B), each pole rod of the first row forming a pole rod pair (112, 300, 400) with a corresponding pole rod of the second row, the pole rod pairs (112, 300, 400) defining a plurality of ion transport cells, each ion transport cell uniquely corresponding to a contiguous group of a fixed number of pole rod pairs, such that no two ion transport cells share a common pole rod pair; and a controller configured to apply voltages in a repeating voltage pattern (500, 600, 700, 800) to the pole rods of the first row (506B, 604B, 706B, 804B); wherein the controller is further configured to apply a common voltage to the pole rods of the second row (506A, 604A, 706A, 804A) thereby creating a plurality of potential wells capable of capturing ions, wherein each ion transport cell receives the same pattern of voltages; move the repeating voltage pattern (500, 600, 700, 800) along the pole rods of the first row (506B, 604B, 706B, 804B) to move captured ions within and between the plurality of ion transport cells along the ion transport device; and apply at least one ejection voltage to one or more electrodes (114, 116) to cause ions to be ejected from the ion transport device; characterised in that the common voltage to the pole rods of the second row (506A, 604A, 706A, 804A) is a fixed voltage. a plurality of pole rods arranged in first (506B, 604B, 706B, 804B) and second rows (506A, 604A, 706A, 804A), the second row (506A, 604A, 706A, 804A) parallel to the first row (506B, 604B, 706B, 804B), each pole rod of the first row forming a pole rod pair (112, 300, 400) with a corresponding pole rod of the second row, the pole rod pairs (112, 300, 400) defining a plurality of ion transport cells, each ion transport cell uniquely corresponding to a contiguous group of a fixed number of pole rod pairs, such that no two ion transport cells share a common pole rod pair; and a controller configured to apply voltages in a repeating voltage pattern (500, 600, 700, 800) to the pole rods of the first row (506B, 604B, 706B, 804B); wherein the controller is further configured to apply a common voltage to the pole rods of the second row (506A, 604A, 706A, 804A) thereby creating a plurality of potential wells capable of capturing ions, wherein each ion transport cell receives the same pattern of voltages; move the repeating voltage pattern (500, 600, 700, 800) along the pole rods of the first row (506B, 604B, 706B, 804B) to move captured ions within and between the plurality of ion transport cells along the ion transport device; and apply at least one ejection voltage to one or more electrodes (114, 116) to cause ions to be ejected from the ion transport device; apply voltages in a repeating voltage pattern (500, 600, 700, 800) to the pole rods of the first row (506B, 604B, 706B, 804B); wherein the controller is further configured to apply a common voltage to the pole rods of the second row (506A, 604A, 706A, 804A) thereby creating a plurality of potential wells capable of capturing ions, wherein each ion transport cell receives the same pattern of voltages; move the repeating voltage pattern (500, 600, 700, 800) along the pole rods of the first row (506B, 604B, 706B, 804B) to move captured ions within and between the plurality of ion transport cells along the ion transport device; and apply at least one ejection voltage to one or more electrodes (114, 116) to cause ions to be ejected from the ion transport device;