Sample project of Laser-induced breakdown spectroscopy for university students. complete project is available below for download
Overview of Laser-induced Breakdown Spectroscopy Project:
Laser-induced breakdown spectroscopy (LIBS) is a laser-based technique that can provide qualitative and quantitative measurements of elements in gas, liquid, and solid samples. It is a technology in which a laser beam is directed at a sample to create a high-temperature micro plasma. . A determination of the background gas on spectral lines and the influence of plasma parameters like temperature and number density are studied. The life-time of the plasma is strongly dependent on the pressure of the background gas. A spectrometer is used to disperse the light emission and detect its intensity at specific wavelengths.
Laser Induced Breakdown Spectroscopy
LIPS (laser plasma spectroscopy) also known as Laser Induced Breakdown Spectroscopy (LIBS), is a relatively new type of atomic emission line Spectroscopy made possible with the advent of the laser in 1961. LIBS was originally Coined by Leon Radziemski and David Cremer’s at LANL (Los Alamos National Laboratory) in New Mexico (USA) in 1981 .
Laser Induced Breakdown Spectroscopy (LIBS) is a technology that uses a short laser pulse to create a micro-plasma on the sample surface. LIBS technology is the formation of high-temperature plasma, induced by a short laser pulse. When a short laser pulse (with typical duration from ns to fs), is focused on a portion of matter, a significant amount of energy is transferred to the lattice, which can result in the formation of a plasma of the irradiated material, a phenomenon usually referred as breakdown at the material surface. The breakdown can occur only if the pulse irradiance exceeds a threshold value which depends on the state of aggregation of the material, an irradiance value of ~1 GW/cm2 is generally considered as an appropriate reference value to yield high-temperature and high-electron density plasma from virtually any kind of irradiated solid targets.
When the laser pulse terminates, the plasma starts to cool down. During the plasma cooling process, the electrons of the atoms and ions at the excited electronic states fall down into natural ground states, causing the plasma to emit light with discrete spectral peaks .The LIB spectra consist of spectral lines which give information about all the constituting elements as well as elements in trace amount present in that sample .
Laser Matter Interaction
The laser-plasma interaction is the transition of the target material into plasma state due to the presence of the laser electric field . Experimentally, laser-induced ionization was observed shortly after the invention of the laser in the sixties already. With advances in laser technology, however, higher intensities, different wavelengths and shorter pulse durations became available. Depending on the laser parameters used, different ionization processes such a Multi-photon ionization, above-threshold ionization and Barrier suppression ionization. The two mechanisms for electron generation and growth which produce breakdown are called multi-photon ionization and inverse bremsstrahlung .
Download Laser-induced Breakdown Spectroscopy Project: