Laser-induced breakdown spectroscopy (LIBS) uses a highly energetic laser pulse to ablate materials and plasmas will be generated. Emission lines from atoms and ions in the plasma will be analyzed to know the kinds and contents of elements in the material. Having the advantages of rapid detection, no sample preparation, and capabilities of on line and remote analysis, LIBS could be used industrial in-line measurement, geological analysis, environmental monitoring, and space applications. Spacial confinement is a cost-effective approach to improve the detection sensitivity of LIBS, and is able to improve the signal intensity, signal-to-noise ratio, signal-to-background ratio, and the accuracy of quantitative analysis.
Under the guidance of Prof. Yongfeng Lu, Prof. Xiaoyan Zeng, and Prof. Xiangyou Li, Changmao Li and Lianbo Guo et al. have studied in deep the laser-induced plasmas under spatial confinements by different hemispheric cavities, and found that there are some connections between the enhancement factors of different elements/lines in plasma under spatial confinement, which could be expressed by two equations developed in this study. The results have described all the factors impacting on the enhancement effect of spatial confinement, and explained in full why the enhancement factors of different elements/lines are different with each other. With the equations developed in this study, enhancement factors of other elements/lines in the plasma can be estimated.
This research has been financially supported by the Major Scientific Instrument and Equipment Development Project (No. 2011YQ160017), and by the National Natural Science Foundation of China (No. 51128501), which has been published on the Journal of Analytical Atomic Spectrometry (Vol. 29, Iss. 4, pp. 638-643, 2014).