High pressure differential pumping particle beam mass spectrometry system

Abstract

The invention discloses a high-pressure differential pumping particle beam mass spectrometry system, comprising: a vacuum and sampling module, a mass spectrometer module, and a beam chopping lock-in amplification module, wherein the vacuum and sampling module includes: a vacuum chamber, a molecular pump and an ionization vacuum Meter and sampler, the sampler is used to introduce the sample to be measured into the vacuum chamber, the mass spectrometer module includes: ionization chamber, quadrupole, detector and data acquisition and processing unit, the beam chopping lock-in amplification module includes: beam chopping sheet and motor, The beam chopping piece and the motor are located in the vacuum chamber, and the motor drives the beam chopping piece to rotate around the center of the beam chopping piece. The part of the beam chopping piece is located between the sampler and the ionization chamber; the light-emitting diode and the photodiode correspond to the light-emitting diode and the photodiode The ground is arranged on both sides of the beam chopping plate for providing a synchronous reference signal; and a lock-in amplifier, the lock-in amplifier is electrically connected with the data acquisition processing unit and the photodiode respectively. The system has the advantages of compact structure, accurate and reliable, and good portability.

Description

technical field [0001] The invention belongs to the field of analytical instruments, in particular to a high-pressure differential pumping particle beam mass spectrometry system. Background technique [0002] A mass spectrometer is a measurement device used to test the chemical composition of gases in a vacuum, and generally consists of an ionization chamber, a quadrupole, a detector, and a data acquisition and processing unit. The gas molecules in the vacuum are ionized into ions by the electrons thermally emitted by the filament in the ionization chamber, and the data acquisition and processing unit controls the quadrupole to select the corresponding ions to collect the ion current to know the chemical composition and content of the corresponding molecules in the vacuum. In order to reduce the collision loss during ion transmission and ensure the normal operation of the electron multiplier detector, the working pressure of the mass spectrometer is generally required to be ...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art, such as too strong background signal, low signal-to-noise ratio, and inaccurate measurement results.

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