Patent ID: 9601323
Date: 2017-03-21
CPC Classifications: H01J

Claim:
1. An ion transport apparatus for transporting ions to a subsequent stage while trapping the ions by an effect of an electric field, comprising: a) an electrode group composed of a plurality of ring electrodes arranged in a substantially concentric pattern around an aperture for sending the ions to the subsequent stage, each ring electrode having a radial sectional shape in which at least a portion facing a side from which the ions arrive has a curved shape or a quasi-curved shape formed by a chain of line segments; and b) a voltage application unit for applying voltages to each of the ring electrodes included in the electrode group, in such a manner as to apply two radio-frequency voltages whose phases are inverted from each other by 180 degrees to any two ring electrodes neighboring each other in a radial direction among the plurality of ring electrodes, and simultaneously, to apply a different level of direct-current voltage to each of the ring electrodes so as to form a direct-current potential gradient which urges the ions from an outer ring electrode to an inner ring electrode of the electrode group.