Optimization of cavity size for spatial confined laser-induced breakdown spectroscopy

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Materials Science

Background:

• Spatial confinement in small cavities is a known method to boost signal intensity in laser-induced breakdown spectroscopy (LIBS).
• Understanding the impact of cavity dimensions on plasma characteristics is crucial for optimizing LIBS performance.

Purpose of the Study:

• To investigate the effect of small cylindrical cavities on the optical emission intensity and signal stability of laser-induced plasmas.
• To determine the optimal cavity dimensions for enhanced signal quality in LIBS analysis of brass samples.

Main Methods:

• Laser-induced plasmas were generated from brass samples.
• Aluminum plates with prefabricated cylindrical cavities of varying diameters and heights were placed near the sample surface.
• Optical emission intensity and signal stability (relative standard deviation) were measured and analyzed.

Main Results:

• Both plasma emission intensity and stability were significantly influenced by cavity diameter and height.
• Emission intensity initially increased with cavity diameter (1.5 mm to 6 mm) before decreasing.
• Optimal cavity sizes were found to improve both line intensity and stability of the confined plasma emission.

Conclusions:

• The use of small cylindrical cavities can effectively enhance the signal intensity and stability of laser-induced plasmas.
• An optimized cavity size was identified for improved LIBS signal quality on brass samples.
• This study provides valuable insights for enhancing LIBS analysis through spatial confinement.