| 主权项 |
1. An ion transport device which is arranged, for the purpose of transporting ions from a first region with a relatively high gas pressure atmosphere to a second region with a relatively low gas pressure atmosphere, in a third region with an atmosphere with gas pressure between that of those two regions, the ion transport device comprising:
a) a first ion transport unit which is arranged on the inlet side from which ions fed from said first region enter, the first ion transport unit comprising multiple ring electrodes arrayed along the ion optical axis and a funnel structure wherein the inside diameter of the opening of the ring electrodes on the inlet side is greater than the inside diameter of the opening of the ring electrodes on the outlet side; b) a second ion transport unit which is arranged after said first ion transport unit, and wherein an even number of four or more virtual rod electrodes, the second ion transport unit comprising a plurality of electrode plates arrayed along the ion optical axis, are arranged about the ion optical axis, and the inscribed circle of the electrode plates contained within each of the virtual rod electrodes within the plane orthogonal to the ion optical axis decreases gradually from the inlet side to the outlet side; c) an aperture electrode which is arranged between said first ion transport unit and said second ion transport unit and has an opening in the center through which ions transit; and d) a voltage generator configured to apply a voltage comprising a superimposed high frequency voltage and direct current voltage to the ring electrodes contained in said first ion transport unit and to the electrode plates contained in said second ion transport unit, and to apply a direct current voltage to said aperture electrode. |
