Ž . Spectrochimica Acta Part B 56 2001 23712383 Parametric study of a fiber-optic laser-induced breakdown spectroscopy probe for analysis of aluminum alloys Awadhesh K. Rai b , Hansheng Zhang a , Fang Yu Yueh a , Jagdish P. Singh a, , Arel Weisburg c a Diagnostic Instrumentation and Analysis Laboratory, Mississippi State Uni ersity, 205 Research Boule ard, Starkille, MS 39762-7704, USA b Department of Physics, G.B.Pant Uni ersity of Ag. & Technology, Pantnagar-263145, India c Energy Research Company, 364 Decker Aenue, Staten Island, NY 10302, USA Received 27 April 2001; accepted 30 July 2001 Abstract Ž . In the present work we demonstrate a fiber-optic laser-induced breakdown spectroscopy FO LIBS system for delivering laser energy to a sample surface to produce a spark as well as to collect the resulting radiation from the Ž . laser-induced spark. In order to improve the signalbackground SB ratio, various experimental parameters, such as laser energy, gate delay and width, detector gain, lenses of different focal lengths and sample surface, were tested. In order to provide high reliability and repeatability in the analysis, we also measured plasma parameters, such as electron density and plasma temperature, and determined their influence on the measurement results. The performance of FO LIBS was also compared with that of a LIBS system that does not use a fiber to transmit the laser beam. LIBS spectra with a good SB were recorded at 2-s gate delay and width. LIBS spectra of six different Al alloy samples were recorded to obtain calibration data. We were able to obtain linear calibration data for Ž . numerous elements Cr, Zn, Fe, Ni, Mn, Mg and Cu . A linear calibration curve for LIBS intensity ratio vs. Ž concentration ratio reduces the effect of physical variables i.e. shot-to-shot power fluctuation, sample-to-surface . distance, and physical properties of the samples . Our results reveal that this system may be useful in designing a high-temperature LIBS probe for measuring the elemental composition of Al melt. 2001 Elsevier Science B.V. All rights reserved. Keywords: Aluminum alloys; Laser-induced breakdown spectroscopy; Fiber optic; Calibration Corresponding author. Tel.: 1-662-325-7375; fax 1-662-325-8465. Ž . E-mail address: singh@dial.msstate.edu J.P. Singh . 0584-854701$ - see front matter 2001 Elsevier Science B.V. All rights reserved. Ž . PII: S 0 5 8 4 - 8 5 4 7 01 00299-3