Segmented linear ion mobility spectrometer driver

Abstract

An ion mobility spectrometer or separator is disclosed comprises plural groups of electrodes, each group of electrodes comprising: (i) a first electrode connected to a first independently controllable voltage supply; (ii) one or more intermediate electrodes; and (iii) a second electrode connected to a second independently controllable voltage supply, wherein the first electrode, the one or more intermediate electrodes and the second electrode are interconnected by a series of resistors or other components so as to form a resistive divider so that the potential of the one or more intermediate electrodes is determined by the voltages supplied by the first and second voltage supplies and the resistance of the resistors; a drift region; a first device arranged and adapted to pulse a packet of ions into the drift region so that the ions are caused to separate temporally and assume one or more ion distributions; and a control system arranged and adapted: (i) to cause at least some of the independently controllable voltage supplies to supply voltages to at least two adjacent groups of electrodes so as to substantially continuously subject at least part or substantially the whole of the one or more ion distributions to a first non-zero voltage gradient or a first non-zero constant or linear electric field as the one or more ion distributions progress along the drift region; and (ii) to cause at least some of the independently controllable voltage supplies to supply voltages to groups of electrodes other than the at least two adjacent groups of electrodes to create, maintain or apply a second different voltage gradient or a second different electric field across one or more portions of the drift region which are distal from the one or more ion distributions.