High repetition frequency assisted ablation laser-induced breakdown spectroscopy aerosol detection device

Abstract

The invention discloses a high repetition frequency auxiliary ablation laser-induced breakdown spectroscopy aerosol detection device, which comprises an aerosol beam generation component, a laser-induced breakdown spectroscopy detection component and a detection component, the auxiliary ablation component is used for focusing the high-repetition-frequency laser on the aerosol beam and continuously exciting aerosol particles in the aerosol beam to pre-form plasma; the high-energy excitation part is used for enabling the high-energy pulse laser to be located at the plasma, so that the high-energy pulse laser excites the plasma before puncturing air; the spectral information acquisition part is used for acquiring optical radiation emitted by the excited plasma and acquiring spectral information of the optical radiation; and the data processing part is used for sequentially controlling the output of the high-energy pulse laser and the acquisition of optical radiation, and processing the spectral information to obtain the element composition of the aerosol to be detected and the content information of each element. According to the invention, the utilization rate of laser energy can be effectively improved, and the sensitivity of aerosol elements in detection is improved.

Description

technical field [0001] The invention belongs to the field of aerosol detection technology and spectrum analysis, and more specifically relates to a high repetition-frequency assisted ablation laser-induced breakdown spectrum aerosol detection device. Background technique [0002] Aerosol is a special dispersion system, and its dispersant is solid or liquid tiny particles with a particle size range of 0.01-1000μm. Because of its small particle size, it can exist in the air for a long time and can be transported with air masses for long distances. It has an important impact on regional climate, environmental pollution, and human health. Therefore, the detection of aerosol concentration and type is an important part of environmental monitoring and is of great significance. [0003] Conventional techniques for detection of aerosol collagen position mainly include gas chromatography-mass spectrometry (GC-MS), atomic absorption spectrometry (AAS), ion chromatography (IC), and so ...

AI Technical Summary

Problems solved by technology

When LIBS technology is used for online detection of aerosols, it is necessary to focus the laser on the position of the aerosol beams. Due to the low concentration of aerosol particles in the aerosol beams and the high transmittance of the aerosol beams, the laser and aerosol particles In the early stage of the gas flow interaction, the plasma has not yet been formed. At this time, the material absorbs less laser light, and a part of the energy is not absorbed by the plasma, but directly passes through, resulting in a waste of part of the laser energy. When the laser energy is saturated, the directly transmitted energy is as high as a unit 20% of the pulse energy, when the laser energy is low, the proportion of the laser energy is higher; when the laser energy is high, because the energy density exceeds the breakdown threshold of the air, a large amount of laser energy is absorbed by the air, and only the remaining A small part of the energy is absorbed by the aerosol particles to be measured, resulting in weak spectral signals of the elements corresponding to the aerosol particles in the generated plasma, and strong spectral signals of the elements corresponding to the air, resulting in the problem of poor sensitivity in the detection of aerosol elements

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