Energy assistance in laser induced plasma spectrometry (LIPS) by a synchronized microsecond-pulsed glow discharge secondary excitation

Abstract

The design and preliminary experimental results are presented of a new LIPS chamber permitting the creation of a sub-sputtering threshold glow discharge (GD) environment that is pulsed synchronously with an ablation laser. The new dual GD-LIPS synchronous scheme provides significant signal enhancements (up to 75×) when compared to LIPS or GD under identical conditions. The possible contributions of the gas pressure, discharge gas and secondary excitation on the commented enhancement are discussed. Our experiments suggest that all of the material ablated by the ablation laser is efficiently excited and used to its full potential. Under the described conditions, it is possible to lower the laser energies needed for the excitation/ionization thresholds of materials to those required solely for ablation of the sample surface, thus creating the possibility of improving lateral and depth resolutions in the spatial characterization of material.