In situ analysis of steel under reduced ambient pressure by laser-induced breakdown spectroscopy

We report on rapid in-situ analysis of liquid and solid steel samples under reduced ambient pressure by laser-induced breakdown spectroscopy (LIBS) using a transportable system. LIBS denotes a technique where a pulsed laser beam is used to ablate small amounts of the target material. The characteristic optical emission line intensities of the excited species in the laser-generated plasma plume allow a quantitative chemical analysis of the target material. Over a wide range of parameters the expansion of the plume can be described by a generalized shock wave model. LIBS is a fast, non-contact method, which can be carried out under various atmospheric conditions allowing large working distances between the sample under investigation and the detection system. These properties make LIBS applicable to process control especially for vacuum devices used in metallurgy.