Patent ID: 7675031
Filing Date: 2010-03-09
Classification: H01J

Abstract:
1. A mass spectrometer having a multipole ion guide device, comprising: an electronic controller; a plurality of main electrodes operably connected to the electronic controller and an RF power source for applying RF voltages in the multipole ion guide device under operation of the electronic controller; at least one auxiliary electrode connected to a DC voltage source via the controller, the at least one auxiliary electrode disposed between at least two adjacent ones of the main electrodes, the at least one auxiliary electrode comprising: electrical elements including at least one array of finger electrodes and a plurality of resistors interconnecting respective finger electrodes of the at least one array; and a substrate supporting the finger electrodes and the resistors; wherein the voltage source applies a static DC voltage to the electrical elements such that the finger electrodes present a monotonically progressive voltage gradient on respective finger electrodes of the array along a length of the auxiliary electrode.