Huazhong University of Science and Technology

Yongfeng Lu

Xiaoyan Zeng

Xiangyou Li

Zhongqi Hao

Jiaming Li

Lianbo Guo

Xinyan Yang

Ran Zhou

Yun Tang

Ping Yang

Rongxing Yi

Meng Shen

The present invention belongs to the technical field of elemental analysis, and more particularly, relates to a dynamic calibration method for echelle spectrometer in laser-induced breakdown spectroscopy, comprising: S1: collecting a standard light source by using an echelle spectrometer; S2: in combination with a calibration function, calculating a pixel position coordinate ({circumflex over (x)},&#x177;) corresponding to a spectral wavelength &#x175;; S3: performing dynamic searching and filtering near the pixel position coordinate ({circumflex over (x)},&#x177;) to obtain a set D of all pixel position coordinates, and adjusting all original intensity values in the set D to obtain intensity values F(I), and S4: calculating a spectral line intensity value after dynamic calibration by summing the adjusted intensity values F(I), thereby completing dynamic calibration of the result of the echelle spectrometer. The method in the present invention can overcome the shortcoming, i.e., the existing echelle spectrometer is only calibrated before measurement without solving the spectral line drift during use, increasing the absolute intensity of the wavelength and reducing the detection limit of the quantitative analysis, as well as improving the precision of the quantitative analysis of an element to be analyzed.

Dynamic calibration method for echelle spectrometer in laser-induced breakdown spectroscopy

The present invention belongs to the field of laser plasma emission spectrometry, and in particular relates to a method for improving the detection sensitivity on a carbon element in laser-induced breakdown spectroscopy. The method specifically comprises the following steps: ablating the surface of a sample to be tested by using a laser beam emitted so as to rapidly heat the surface of the sample and the ambient air close to the surface of the sample into plasma, atomize carbon in the sample and nitrogen in the ambient gas, and combine carbon with the nitrogen into C&#x2014;N radicals; tuning a wavelength-tunable laser to a wavelength needed by stimulated absorption transition of C&#x2014;N radicals, and outputting a laser beam to radiate the plasma so that stimulated absorption transition of C&#x2014;N radicals is carried out, then fluorescent signals are emitted with spontaneous radiative transition; collecting and recording an emission fluorescence spectrum of the C&#x2014;N radicals; and qualitatively or quantitatively analyzing on carbon element. By adopting the method provided by the invention, in a case of hardly affecting the matrix spectrum, C&#x2014;N radical signal can be enhanced in high selectivity, thereby avoiding the interference generated by the matrix, and spectrum signals of the carbon element in the plasma can be enhanced, thereby improving the detective sensitivity of LIBS on carbon element.

Method for improving detective sensitivity on carbon element in laser-induced breakdown spectroscopy

Provided is a method for inhibiting self-absorption effect of a LIBS, comprising ablating a to-be-measured sample via a pulse laser thereby generating plasma, and selectively stimulating the plasma using a wavelength-tunable laser beam enabling transition of particles in a ground-state in the plasma to high energy state as stimulated absorption, thereby improving a stimulated absorption transition efficiency of the particles in a ground-state, and preventing plasma spectrum from being influenced by self-absorption effect. The invention is capable of eliminating the self-absorption effect without introducing external interference, obtaining original characteristics of emission spectrum from the center of the plasma, and essentially inhibiting and finally eliminating the self-absorption effect of laser plasma by making use of intrinsic physical property of plasma.

Method for inhibiting self-absorption effect in laser-induced breakdown spectroscopy

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Hubei, China

Yongfeng Lu