Effect of ICCD gain on the spectral characteristics of laser-induced alloy steel

Abstract

ICCD was one of the main instruments in the experimental system of Laser-induced breakdown spectroscopy (LIBS). It was used to realize photoelectric conversion. Gain was the key parameter of ICCD, and the gain had a great influence on the acquisition of spectra. In this paper, the effect of ICCD gain on the intensity and Signal-to-Background Ratio (SBR) of the laser-induced alloy steel spectra has been investigated. Furthermore, the influence of ICCD gain on the detection sensitivity and detection of limit (LOD) of the trace elements (Mn, Cr)in alloy steel has also been studied. It is found that when the ICCD gain varies from 0 to 4000, both the spectral intensity and background increase with the gain, and the SBR of the spectra first shows a rapid growth trend with the increase of the gain. Then the curve of the SBR with the gain has a tendency of saturation. The internal standard method is used to quantitatively analyze the trace elements (Mn, Cr) in the alloy steel. The results have shown that the ICCD gain affects the detection sensitivity of the elements. With the increase of the gain, the LOD of the two elements is decreasing gradually. When the gain is greater than 2000, the LOD is stable at a certain value. Considering the results of spectral signal and quantitative analysis of the trace elements, the optimal ICCD gain can be set to 2000. The results of this paper will help to further optimize the parameters of the experimental system and improve the analysis performance of LIBS.