Laser-induced plasma spectroscopy
The laser-induced plasma spectroscopy - short LIPS or LIBS (for engl. Laser-Induced Breakdown Spectroscopy ) - is a laser spectroscopic method with which the element-specific composition of a sample can be determined. Due to its comparatively simple application, it is widespread (among other things, for rapid analysis of metals in scrap yards with a handheld laser spectrometer ). It is a variant of atomic emission spectrometry .
Working principle
By bombarding a sample with short laser pulses, a small volume of the sample is vaporized and ionized to form a plasma ( laser ablation ). When the plasma decays, light is emitted which is characteristic of the elements it contains. The spectrum of the radiation is recorded with a spectrometer .
The atomic composition of the sample can be determined from the intensity spectrum. With time-resolved measurements of the spectrum, it is also possible to detect molecular bands.
Advantages over other analysis methods
Laser-induced plasma spectroscopy often does not require any sample preparation and is relatively non-destructive. It enables the qualitative and - with appropriate calibration - the quantitative determination of the atomic composition of a sample simultaneously for a large number of elements. The material to be examined can be solid, liquid or gaseous and electrical conductivity is not required. By removing material from the laser radiation, non-representative cover layers can be removed and / or depth profiles of a sample can be recorded.
disadvantage
Both the generation and guidance of the laser beam and the detection of the plasma light are more or less complex systems. Spark spectrometers, in which the plasma is generated by an electric arc, are therefore not only more robust, but also significantly cheaper.
In the case of inhomogeneous materials (e.g. ores), only the material components that are within the laser beam are included in the measurement result.
Areas of application
An instrument called a ChemCam is used by the Curiosity rover on Mars.
Individual evidence
- ↑ LAC: Laser-Induced Plasma Spectroscopy (LIBS)
- ↑ SECOPTA GmbH Berlin: LIBS (Laser Induced Breakdown Spectroscopy) ( Memento of the original from January 5, 2017 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
