Laser Induced Breakdown Spectroscopy (LIBS)
Laser-induced breakdown spectroscopy (LIBS) is an elemental analytical technique with the ability to detect and quantify elemental composition (both heavy and light elements) in a solid, liquid or even gas state. LIBS involves the creation of a high temperature plasma above the sample. This plasma is created by laser pulse from a laser source. When the micron-sized laser beam is focused onto the sample surface, a small volume (micrograms) of the sample mass is ablated. When the laser pulse/plasma creation is complete, the plasma starts to cool. It’s during this process that the electrons of the atoms and ions at the excited electronic states fall down into natural ground states. This causes the plasma to emit light with characteristic spectral peaks. The emitted light is collected and transmitted to the spectrometer/CCD package for LIBS analysis. Each element in the periodic table has a number of unique LIBS’ spectral peaks. These peaks are collected and integrated to calculate concentration of materials, such as metal alloys.
LIBS, unlike the other popular analytical technique of X-ray Fluorescence (XRF), is inherently more sensitive and better suited for light element detection – such as aluminum (Al), lithium (Li), magnesium (Mg), and beryllium (Be). However, reliable LIBS analysis of materials with these elements, especially at the point-of-need, has been very limited and typically confined to a laboratory environment -until now. Recent technological advancements, such as miniature, solid state micro-lasers as well as small, compact spectrometers have made the design of handheld LIBS possible and rapidly expanded the use of this versatile technique into field operations – such as alloy sorting and analysis. Its ability to analyze light elements in the field translates into the identification of even more metals and alloys than afforded by traditional use of XRF for this application.