Application of Response Surface Methodology to laser-induced breakdown spectroscopy: Influences of hardware configuration

Response Surface Methodology (RSM) was employed to optimize LIBS analysis of single crystal silicon at atmospheric pressure and under vacuum conditions (pressure ∼ 10− 6 mbar). Multivariate analysis software (StatGraphics 5.1) was used to design and analyze several multi-level, full factorial RSM experiments. A Quality Factor (QF) was conceived as the response parameter for the experiments, representing the quality of the LIBS spectrum captured for a given hardware configuration. The QF enabled the hardware configuration to be adjusted so that a best compromise between resolution, signal intensity and signal noise could be achieved. The effect on the QF of simultaneously adjusting spectrometer gain, gate delay, gate width, lens position and spectrometer slit width was investigated, and the conditions yielding the best QF determined.