Three dimensional characterization of laser ablation craters using high resolution X-ray computed tomography

Laboratory X-ray computed tomography is an emerging technology for the 3D characterization and dimensional analysis of many types of materials. In this work we demonstrate the usefulness of this characterization method for the full three dimensional analysis of laser ablation craters, in the context of a laser induced breakdown spectroscopy setup. Laser induced breakdown spectroscopy relies on laser ablation for sampling the material of interest. We demonstrate here qualitatively (in images) and quantitatively (in terms of crater cone angles, depths, diameters and volume) laser ablation crater analysis in 3D for metal (aluminum) and rock (false gold ore). We show the effect of a Gaussian beam profile on the resulting crater geometry, as well as the first visual evidence of undercutting in the rock sample, most likely due to ejection of relatively large grains. The method holds promise for optimization of laser ablation setups especially for laser induced breakdown spectroscopy. [Display omitted] •Laser ablation induced craters made on aluminum and rock samples were characterized using CT scan.•The measurements by the CT scan were very similar to the theoretical simulation used to describe the laser induced craters.•The CT scan serves as a useful technique for examining the shape of the craters and enables accurate measurement.•The high resolution CT undercut crater images can reveal fine details that can be useful for spectroscopic investigations.