An Ion Mobility Spectrometry Device Based on Corona Discharge

Abstract

The invention discloses an ion mobility spectrometer device based on corona discharge, which comprises a corona discharge ion source, an ion migration unit and an electrical signal processing unit. The corona discharge ion source includes a discharge wire, a ground electrode, a shielding layer, a gas and sample inlet I, a gas outlet I, and a wire support; the ion migration unit includes an ion migration member, an ion gate, a pulse power supply, a ring metal electrode, Fixed-value resistance, DC power supply, gas outlet II and gas inlet II; the electrical signal processing unit includes a Faraday disk and a shielding metal plate; the Faraday disk is arranged on the inner end surface of the ion migration component, and its diameter is greater than the inner diameter of the ion migration component; The shielding metal plate is arranged on the outer end surface of the ion migration component, wherein there is a certain gap between the Faraday disk and the shielding metal plate, and the diameter of the shielding metal plate is larger than the outer diameter of the ion migration component. The sensitivity of the ion mobility spectrometer can be improved.

Description

technical field [0001] The invention belongs to the technical field of detection, and in particular relates to an ion mobility spectrometer device based on corona discharge. Background technique [0002] Ion mobility spectrometer (IMS) is a trace gaseous chemical substance detection device, which is widely used in military, medical, biological, environmental and other fields. It mainly separates ions with different mobility in the electric field by ionizing gaseous substances, and then obtains the ion mobility spectrum of the sample gas ionization products. The main part of the ion mobility spectrometer is the transfer tube. The ionization source is one of the main components of the transfer tube, and its main function is to ionize the sample gas passed into the transfer tube. Most ion mobility spectrometers currently in use use Ni 63 source of radioactive ions. Ni 63 As a radioactive ion source, it has the advantages of stability and no energy consumption. However, du...

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Problems solved by technology

But in fact, the corona needle tip is relatively easy to oxidize, and when it needs to be replaced, due to the limitation of processing technology and cost, it is difficult to ensure that the curvature of the needle tip used every time is exactly the same

On the other hand, the current of needle tip corona is very small. Although multiple needles can be used to increase the current, it involves the problem of their consistency.

In addition, the traditional needle electrode corona ion source has a large electromagnetic interference, and the grounded metal mesh shielding structure makes many charged ions absorbed by the metal mesh, which also leads to a large loss of ion flow

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