Influence of Soil Porosity on Characteristics of Laser-Induced Soil Plasmas

Abstract

The influence of soil porosity on characteristics of laser-induced breakdown spectroscopy (LIBS) of metal element Pb in soil is measured and analysed, using Nd:YAG (wavelength of 1064 nm) laser as the excitation source to induce soil plasma in the natural environment of the laboratory. The experimental results show that the spectral line intensity and plasma temperature increase with porosity firstly, and then change slowly. The minimum relative standard deviation of the spectral intensity is at the pressure of 1400 N. The internal standard method and background correction method are used to correct the influence of soil porosity, to some extent, reducing the porosity of the soil.