Improving the Limit of Detection in Laser-Induced Breakdown Spectroscopy and Measuring the Associated Plasma Parameters

H. Hegazy

Abstract: The current study aimed to measure the plasma parameters corresponding to the improved limit of detection and precision for the technique of laser-induced breakdown spectroscopy (LIBS). In this study, the plasma was generated by focusing a 6 ns pulsed NdYAG laser at the fundamental wavelength of 1064nm and at the second harmonic wavelength of 532nm on an aluminium (Al) target in air at atmospheric pressure. The emission spectrum was recorded using an Echelle spectrometer equipped with an ICCD camera. The thermometric lines used for the determination of plasma temperature based on the Boltzmann plot were O I and Mn I spectral lines. Additionally, the Stark broadening method was employed for electron density measurements. Several spectral lines, such as the Ha line for hydrogenic species and O I, Al II, and Si I lines for non-hydrogenic species, were used to determine the electron density from the Stark full-width at half-maximum (FWHM).

Keywords: Laser-Induced Breakdown Spectroscopy, LIBS, Laser-produced Plasma Temperature and density, and Optical Emission Spectroscopy