Measurement of atomic transition probabilities with laser-induced breakdown spectroscopy using the 3D Boltzmann plot method

This work presents a method for the determination of atomic transition probability of the emission lines of a given element using the 3D Boltzmann plot method. The method exploits the third (temporal) dimension of a classical 2D Boltzmann plot for the determination of the plasma parameters. As an example and test of the proposed method, we acquired several time-resolved spectra during laser ablation of pure tungsten sample at different energies. The time interval in which the conditions of Local Thermal Equilibrium can be guaranteed was estimated. The results lead to a criterion for the selection of preferred atomic spectral for the measurements of plasma parameters. The effect of self-absorption on the measured transition probabilities is also evaluated and discussed.