Study of Spark Discharge Assisted to Enhancement of Laser-Induced Breakdown Spectroscopic Detection for Metal Materials

In this work, laser triggered spark discharge was combined with laser-ablation under Air and Ar gases to investigate the characteristics of laser-ablated plasma emission. The experimental results show that the optical emission intensity is significantly enhanced by electric discharge compared to without discharge and the spectral emission time of plasma is much longer than that without discharge. The enhancement effect is more apparent in the presence of Ar ambient. In addition, the plasma temperature and electron density as well as limits of detections (LOD) have been determined. The better LOD can be attributed to the improvement of plasma. The higher plasma temperature and electron density indicate that the enhanced mechanism in emission intensity is predominated by the further excitation/ionization of the laser-ablated material by the spark discharge due to the energy deposition in the plasma.