High-speed spectrally-resolved imaging of the laser ablation plasma

Summary form only given. The paper is devoted to the experimental investigation of the laser ablation. Free surface of the liquid phase gallium-indium alloy in vacuum was served as the ablation target. For the ablation, compact Nd-YAG laser pumped by LED was used, generating the irradiation pulse with energy content of 0.28 mJ/pulse at the FWHM duration of 2.7 ns. Method of spectrally-resolved frame imaging was realized for the visualization the luminescence of different plasma species. 4-channel intensified frame camera HSFC-Pro with the minimum exposure time of 3 ns was used. Three channels of the camera were equipped with the narrow-band interference optical filters for the registration the line radiation originated from different gallium components: neutral atoms, single- and double-charged ions. Spectral-spatial structure of plasma glowing was analyzed as well as the dynamics of expansion of plasma including the expansion of differently-charged components. It was demonstrated that the expansion velocity of heavy plasma components increases with the charge state of particles. Quantitatively, the results are in a good agreement with the data of mass-energy analysis performed earlier.