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FIZIKA A 4 (1995) 2, 449-456
 
NITROGEN LASER BEAM INTERACTION WITH TITANIUM SURFACE
VIŠNJA HENČ-BARTOLIĆ*, ŽELJKO ANDREIĆ+, DAVOR
GRACIN+, HANS-J. KUNZE++ and MIRKO STUBIČAR**
*Department of Applied Physics, Faculty of Electrical Engineering and
Computing, University of Zagreb, Unska 3, 10000 Zagreb, Croatia,
+Ruđer Boškovć Institute, Dept. of Physics, Bijenička 54, 10000 Zagreb,
Croatia,
++Ruhr Universität Bochum, Institut für Experimentalphysik V,
Universitätstrasse, 44780 Bochum, Germany
**Department of Physics, Faculty of Science, University of Zagreb, Bijenička
32, 10000 Zagreb, Croatia
Received 7 April 1995
Revised manuscript received 14 August 1995
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.
UDC 533.9
PACS 52.50.Jm, 61.80.Ba
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