Patent ID: 6727495
Filing Date: 2004-04-27
Classification: G01N

Abstract:
An ion mobility spectrometer comprising:a drift tube in said ion mobility spectrometer having a central axis and first and second ends; an ion source for directing ions into the first end of the drift tube; a plurality of ring electrodes arranged along the central axis of the drift tube providing a linear potential gradient along the central axis of the drift tube, each having an internal region defining a radial space perpendicular to the central axis of the drift tube; and an RF voltage source coupled to the plurality of ring electrodes and generating an oscillating RF potential within the internal region of each of the ring electrodes, the oscillating RF potential influencing radial motion of the ions within the drift tube so that the ions remain within the radial spaces defined by the internal regions of the electrodes while moving axially to the second end of the drift tube.