Effect of incoherent optical pumping of plasma in laser-induced breakdown spectroscopy

Abstract

• Incoherent optical pumping of LIP to improve the LIBS method is proposed. • The SSR enhancement of the Cu I persistent lines by more than 2 was confirmed. • The absorbed energy in the expanding plasma is estimated by numerical simulation. • The Boltzmann method was used to study the evolution of LIP electron temperature . The optical pumping of laser-induced plasma (LIP) by incoherent light of a small, fast-discharge, low-energy xenon flashlamp is proposed. The experimental results confirm the enhancement of the intensity of the persistent spectral lines of atomic copper by a factor of more than 2 with 1.5 J flashlamp discharge energy. The peak absorbed pumping energy in a spherically expanding plasma with a radius equal to the radial position of the observation point is of the order 10 mJ. The experimental findings are based on an unoptimized setup without any optical devices for guiding or focusing the pumping radiation. This idea demonstrates that the non-resonant optical pumping of LIP by flashlamp, or some other pulsed white light source can be employed to improve the sensitivity of the laser-induced breakdown spectroscopy (LIBS) method.