Applications of the double-pulse laser-induced breakdown spectroscopy (LIBS) in the collinear beam geometry to the elemental analysis of different materials Céline Gautier a, ⁎ , Pascal Fichet a , Denis Menut a , Jean Dubessy b a CEA (Commissariat à l'Energie Atomique) Saclay, Nuclear Energy Division, LRSI (Laboratoire de Réactivité des Surfaces et des Interfaces), Bâtiment 391, 91191 Gif-sur-Yvette, France b CREGU-G2R UMR 7566, Université Henri Poincaré, Nancy 1, BP 239, 54501 Vandoeuvre-lès-Nancy Cedex, France Received 13 July 2005; accepted 20 January 2006 Available online 3 March 2006 Abstract Double-pulse laser-induced breakdown spectroscopy studies were performed on different types of materials (synthetic glasses, rocks, steels). Two Nd:YAG lasers emitting at 532nm were combined in the collinear beam geometry to carry out double-pulse experiments at atmospheric pressure in air. For all matrices, the influence of the delay between the two laser pulses was systematically investigated from temporal and spectral analyses. Furthermore, the correlation between the excitation energy levels of the emission lines and the increases in intensity induced by the double-pulse scheme was described for each material. A comparison of the studies displayed different behaviors of the materials in the double- pulse experiments. An interpretation of the results is provided on the basis of the determination of the plasma temperatures in the single- and double-pulse configuration with the Saha–Boltzmann plot method. It also gave an insight into the potentialities and the limitations of the double- pulse laser-induced breakdown spectroscopy (LIBS) for analytical purpose so that the materials can be classified in terms of effectiveness of the double-pulse approach. © 2006 Elsevier B.V. All rights reserved. Keywords: Laser-induced breakdown spectroscopy (LIBS); Double-pulse; Aluminum; Glass; Steel; Rock; Matrix effect; Echelle spectrometer 1. Introduction Laser-induced breakdown spectroscopy (LIBS) is based on the spectral analysis of emission lines of elements inside a plasma induced by the focusing of a pulsed laser beam [1]. This analytical technique enables the determination of elemental compositions of different types of materials [2,3]. LIBS can be used in hostile environments using remote sensing methods, such as for nuclear applications [4–7]. LIBS is also an interesting technique for in situ field applications, such as for geological [8–11] or environmental issues [12,13]. But, elements of nuclear or geological interest, such as halogens [14–16] or sulfur [11,17], are not easily detected by LIBS owing to the high excitation energy levels of their emission lines Spectrochimica Acta Part B 61 (2006) 210 – 219 www.elsevier.com/locate/sab ⁎ Corresponding author. Tel.: +33 1 69 08 79 55; fax: +33 1 69 08 86 91. E-mail address: gautier@carnac.cea.fr (C. Gautier). Fig. 1. Schematic diagram of the experimental setup for the double-pulse experiments in the collinear geometry. 0584-8547/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.sab.2006.01.005