Effect of the distance between focusing lens and target surface on quantitative analysis of Mn element in aluminum alloys by using filament-induced breakdown spectroscopy

Ultrafast laser filament-induced breakdown spectroscopy (FIBS) is a potential technique for quantitative analysis of trace elements. In this work, we investigate the effect of the distance between focusing lens and target surface on the FIBS quantitative analysis of Mn element in aluminum alloys, and several major parameters are calculated such as the linear correlation coefficient (R²), limits of detection (LOD), relative standard deviation (RSD), and root-mean-square error of cross-validations (RMSECV). The results show that the quantitative analysis parameter values before and after filament position are different. The optimal value can be obtained at the filament region, the average values of total 23 positions of R², LOD, RSD, and RMAECV were 99.45%, 1.41 mg/kg, 7.12%, and 0.56%, respectively. Besides, the spatial distributions of quantitative analysis parameter values in filament region are noticeable, and this is essentially due to intensity clamping effect in a filament.