采用Nd∶YAG脉冲激光器输出单脉冲序列激光重复作用于土壤样品表面同一位置使其形成熔穴,由光栅光谱仪和ICCD采集每个激光序列脉冲的等离子体发射光谱,研究了激光诱导熔穴对土壤样品等离子体辐射特性的影响。实验结果显示,在熔穴的约束作用下,Cr和Pb元素的谱线强度和信背比都随激光序列脉冲个数的增加呈先增大后减小的变化趋势;熔穴约束的最佳尺寸为直径1.0 mm、深度2.5 mm。随着激光脉冲个数的增加,FeⅠ422.64 nm自吸程度逐渐降低直至消失。研究结果表明,在熔穴孔径的约束作用下,谱线强度和信背比大幅提高,等离子体电子温度升高,有效地降低了谱线的自吸程度。 The Nd: YAG pulse laser output single pulse laser repetitively applied to the same position on the surface of soil samples to form a melting point. The plasma emission spectra of each laser pulse were collected by grating spectrometer and ICCD. The effect of laser induced melting on soil Effect of Sample Plasma Radiation Characteristics. The experimental results show that the line intensity and signal-to-background ratio of Cr and Pb elements increase first and then decrease with the increase of laser pulse number under the constraint of melting point. The optimum size It is 1.0 mm in diameter and 2.5 mm in depth. With the increase of the number of laser pulses, the self-priming of FeI422.64 nm gradually decreased until it disappeared. The results show that under the confinement of the melted aperture, the intensity of the line and the signal-to-background ratio are greatly increased, and the plasma electron temperature is increased, effectively reducing the degree of self-absorption of the line.