Ion lens system for adverse pressure gradient transmission

Abstract

The invention relates to an ion lens system for adverse pressure gradient transmission. The ion lens system comprises first electrostatic lens groups and second electrostatic lens groups which are sequentially connected in series in an incident direction of an ion beam, the number of lenses of the first electrostatic lens groups is greater than or equal to three and is an odd number; each electrostatic lens in the first electrostatic lens groups is coaxially arranged, the voltage applied by the odd-numbered first electrostatic lens is U1, the voltage applied by the even-numbered first electrostatic lens is U2, and U1 is not equal to U2; and the number of the lenses of the second electrostatic lens groups is larger than or equal to two, all the electrostatic lenses in the second electrostatic lens groups are coaxially arranged, a through hole is formed in the center of each second electrostatic lens group, and the hole diameter of each through hole is gradually decreased in the incidentdirection of the ion beam. The ion lens system can accurately adjust the voltage of each electrostatic lens in the ion transmission process, reduces the ion flux loss during voltage gradient transmission, is coupled with a reverse voltage injector, and achieves the effective transmission of ions under the reverse voltage gradient.

Description

technical field [0001] The invention relates to an ion lens system for reverse pressure gradient transmission, which belongs to the technical field of ion optics. Background technique [0002] An electrostatic lens generally refers to a device that focuses or forms an image of an electron beam by an electrostatic field generated by a charged conductor. It is widely used in electronic devices, such as cathode ray oscilloscope tubes, electron microscopes and gas phase reaction instruments. The ion lens system consists of multiple electrostatic lenses. A certain DC voltage is applied to the conductive electrodes of several rotationally symmetrical electrostatic lenses to form a rotationally symmetrical electrostatic field. The main function of the ion lens system is to send most of the ions in the ionization chamber to the target equipment with a small divergence angle, such as mass analyzer, reaction tube, ion trap, etc. [0003] The reverse pressure gradient refers to the ...

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Problems solved by technology

[0004] At present, ion lens systems are mostly used in high vacuum without pressure gradients. There is no good solution for how to effectively focus and transmit ions when there is an adverse pressure gradient.

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