Comparison and optimizaiton of gated and ungated libs systems

• Main Author: Sim, Yit Ching
• Format: Thesis
• Language: English
• Published: 2017
• Subjects: QC Physics
• Online Access: http://eprints.utm.my/id/eprint/81422/1/SimYitChingMFS2017.pdf; http://eprints.utm.my/id/eprint/81422/; http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:124858

Laser-induced breakdown spectroscopy (LIBS) is a direct and versatile analytical technique that performs the elemental composition analysis based on optical emission. The performance of the LIBS technique relies on the choice of experimental conditions. High cost, accuracy and precision insufficiency, understanding of experimental conditions are key challenges in LIBS. In this research work, a comparison between gated and ungated LIBS systems is presented to determine the efficiency and applicability of ungated LIBS system in context of quantities analysis of elements. Two different LIBS systems gated (high cost) and ungated (low cost) are compared for quantitative analysis of Ca and Mg elements which are prepared in laboratory with known composition. Optimization of experimental parameters (Gate delay, integration time, and laser energy) has performed for both gated and ungated LIBS systems to compare performance of two systems based on signal to background ratio. The calibration curves are plotted to determine the accuracy and sensitivity of both gated and ungated systems. The accuracy of system is obtained from regression (R2) and sensitivity from the slope of plotted calibration curves at optimized conditions for both LIBS systems. The R2 and slope values obtained from calibration curves show that the gated measurements are better as compared to those values obtained from the ungated measurements. However, the R2 > 0.8 obtained from calibration curves with ungated measurements indicates the potential of ungated LIBS for quantitative investigations which can be further improved by mitigating the influencing factor.