Original scientific paper
Nitrogen laser beam interaction with titanium surface
Višnja Henč-Bartolić
; Department of Applied Physics, Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, 10000 Zagreb, Croatia
Željko Andreić
; Ruđer Boškovć Institute, Dept. of Physics, Bijenička 54, 10000 Zagreb, Croatia
Davor Gracin
; Ruđer Boškovć Institute, Dept. of Physics, Bijenička 54, 10000 Zagreb, Croatia
Hans-J. Kunze
; Ruhr Universität Bochum, Institut für Experimentalphysik V, Universitätstrasse, 44780 Bochum, Germany
Mirko Stubičar
; Department of Applied Physics, Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, 10000 Zagreb, Croatia; Department of Physics, Faculty of Science, University of Zagreb, Bijenička 32, 10000 Zagreb, Croatia
Abstract
Solid titanium target was irradiated with a N2 laser beam of a maximal energy density of 1.1 J/cm2 per pulse and of a duration of 6 ns. The plasma, formed near the titanium surface, was analyzed by emission spectroscopy, and the irradiated Ti surface was studied by a metallographic microscope. The results of both investigations reveal the influence of resonant absorption of the laser radiation by the generated plasma. The plasma is dense and strongly ionized, with an electron density of 1.5×1018 cm-3 and electron temperature of 2.7 eV. The surface heating was found to be several times more efficient than in the cases when resonant absorption is absent. Most of the observed surface patterns appear to be caused by nonuniform surface heating and a very rapid cooling. The other features are interpreted as a possible consequence of plasma-hot surface interactions.
Keywords
Hrčak ID:
299503
URI
Publication date:
2.5.1995.
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