Effect of voltage and capacitance in nanosecond pulse discharge enhanced laser-induced breakdown spectroscopy.

The laser ablation fast pulse discharge plasma spectroscopy (LA-FPDPS) technique has demonstrated its validity to enhance the optical emission of laser-induced plasma. It has the potential to improve the performance of traditional LIBS measurement. Very recently, LA-FPDPS with a nanosecond pulse discharge circuit has been developed, which has a better capability to enhance the optical emission intensity of laser plasma compared with that using a microsecond pulse discharge circuit. In this paper, the effect of the discharge capacitance and discharge voltage on the optical emission of soil plasma generated by LA-FPDPS with a nanosecond pulse discharge circuit is evaluated in detail. In addition, the stability of the time delay between the laser firing and discharge, and between the discharge and optical emission, has been carefully investigated.