NIST LIBS Database

NIST LIBS Database ?

A. Kramida, K. Olsen, and Yu. Ralchenko
Atomic Spectroscopy Group, Quantum Measurement Division

This interface provides a convenient and straightforward access to the ASD data of relevance to the Laser-Induced Breakdown Spectroscopy (LIBS) applications.

A user can select an arbitrary number of elements for spectra generation with percentage indicating the fraction (in per cent) of the total atom density. The sum of all percentages should be equal to 100. For a given combination of electron temperature and electron density, the ion populations for the lowest three ions of a particular element are calculated using the Saha ionization equilibrium formulas, and the level populations are calculated according to the Boltzmann distribution function accounting for fractional ion populations and selected abundances of the elements. Please note that this Saha-LTE (local thermodynamic equilibrium) approximation is best used for description of low-temperature high-density plasmas (see, e.g., Principles of Plasma Spectroscopy by H.R. Griem). The final spectra are determined using the level populations and radiative transition probabilities (assuming optically-thin steady-state plasma), and the spectral lines are broadened with the Gauss profile accounting for the chosen line resolution. The interface also allows uploading user's data (e.g., experimentally measured spectra) for comparisons with the calculated results.

National Institute of Standards and Technology