Effect of laser intensity and dynamics of plasma on laser induced breakdown spectroscopy

TL;DR

This paper investigates how laser intensity and plasma dynamics influence LIBS signal enhancement, demonstrating significant improvements through magnetic and spatial confinement, with theoretical analysis aligning with experimental results.

Contribution

It presents a comprehensive study on LIBS signal enhancement using magnetic and spatial confinement, including theoretical analysis and experimental validation.

Findings

Magnetic confinement doubles LIBS signal.

Combined magnetic and spatial confinement enhances LIBS signal by an order of magnitude.

LIBS signal saturation correlates with electron-ion collision frequency and plasma instability.

Abstract

Laser-induced breakdown spectroscopy (LIBS) show enhancement in its signal, when the laser-induced plasma is confined/decelerated under the effect of an external steady magnetic field or in a small cavity. An enhancement in LIBS signal has been observed ~2 times in the case of magnetic confinement. Combination of magnetic and spatial confinement provide enhancement by an order of magnitude. Theoretical analysis of the decelerated plasma has been found in agreement with the experimental observations. The enhancement in LIBS signal is found dependent on the efficiency of plasma confinement as well as on the time duration of laser. The saturation in LIBS signal at higher laser intensity is found correlated with electron-ion collision frequency as well as on the dynamics and instability of plasma plume. Possibility of further enhancement in emission has also been discussed.