Optimization of Signal-to-Noise Ratio for Fine Aerosol LIBS

Abstract

This thesis focuses on the optimization of the Signal-to-Noise Ratio (SNR) for fine aerosol Laser-Induced Breakdown Spectroscopy (LIBS). The objective is to investigate the impact of particle diameter and energy levels with specific gate delays on SNR. The energy levels studied include 1.5 mJ, 2 mJ, and 3 mJ, while the particle diameters examined are 400 nm, 500 nm, and 600 nm. The analysis includes a reference point of 2 mJ, 500 nm for particle diameter, and 500 ns gate delay. The thesis begins with an introduction to LIBS as a state-of-the-art spectroscopic technique and highlights the importance of optimizing SNR in LIBS technology. It provides an overview of aerosols, their size range, morphology, and composition, emphasizing the characteristics of fine aerosol particles and their relevance to LIBS analysis. The principles of LIBS and the physics of plasma formation are discussed, including the concept of double-pulse LIBS. The experimental methodology, including the setup of the LIBS system and data acquisition and processing techniques, is described in detail. The experimental results and discussion section present the analysis of spectrum plots, distribution of parameters, the effect of particle diameter on various parameters and gate delays, the relationship between energy levels and gate delays, and the assessment of successful hits. Meaningful deductions are made based on the findings, highlighting the interplay between energy, gate delay, particle diameter, and SNR optimization.

In conclusion, optimizing SNR in fine aerosol LIBS is crucial for improving the accuracy and sensitivity of the analysis. The analysis of particle diameter, energy levels, gate delays, and successful hits provides valuable insights into the factors influencing SNR. Future work involves exploring additional parameters and advanced data processing techniques, as well as expanding the application of fine aerosol LIBS in various research fields.