Advanced model for the interaction of a Ti plume produced by a ns-pulsed laser in a nitrogen environment

The expansion of a titanium plume evaporated by a ns laser pulse and expanding in nitrogen environment has been investigated by means of a numerical model. The 2D fluid dynamic equations have been coupled with a chemical model implementing the state-to-state kinetics of nitrogen molecules, focusing on the role of molecular vibration in the plasma evolution. The calculated vibrational distributions considerably depart from the Boltzmann one, showing overpopulated tails. Large differences with results obtained considering macroscopic models have been predicted.