Effect of ambient pressure on laser ablation and plume expansion dynamics: A numerical simulation
- Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk-Antwerp (Belgium)
A comprehensive numerical model is applied to the study of the effect of ambient pressure in laser ablation, more specifically on the copper target heating, melting and vaporization, and the resulting plume expansion in the helium gas, as well as on plasma formation in the plume. Under the laser pulse condition investigated [5 ns full width at half maximum (FWHM) and 10{sup 9} W/cm{sup 2} peak irradiance], the calculated results show that the characteristics of the surface temperature and the evaporation depth are very similar even when the ambient pressure varies greatly. The influence of the ambient pressure on the fraction of absorbed laser energy is also small. The maximum ablated material vapor density in the plume is influenced slightly by the different pressures. Before 40 ns, the maximum plume temperature for various ambient pressures is in the order of a few 10{sup 4} K. However, the effect of ambient pressure on the plume length is quite large. A specific calculation for a Gaussian-shaped laser pulse with 6 ns FWHM and 2.76x10{sup 9} W/cm{sup 2} peak irradiance is made. The calculated evaporation depth agrees well with the experimental data. Therefore, the model can be useful to predict trends in target and plume (plasma) characteristics, which are difficult to obtain experimentally for various ambient pressures.
- OSTI ID:
- 20787971
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 99; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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