Javad Fileh kesh - Physics research center, Imam-Hosein University, Tehran, Iran
Javad Khalilzadeh - Physics research center, Imam-Hosein University, Tehran, Iran
Mohammad amin Bassam - Laser Research Center, Malek-Ashtar University of technology, Tehran, Iran

Laser-Induced Breakdown Spectroscopy (LIBS) is a powerful optical emission spectroscopy analytical tool capable of sampling solids, liquids and gases for research and industrial applications[1]. the analytical performance of the LIBS technique depends strongly on the choice of experimental conditions that influence the laser-produced plasma characteristics[2]. the excitation properties of the LIBS plasma are strongly dependent on the pressure of the surrounding atmosphere, which can have a strong effect on the detection of elements in a solid[3]. In this experimental work, in order to optimizing Laser Induced Breakdown Spectroscopy analysis results, various ambient N2 gas (18 different pressures) were examined. the optimum pressure was achieved, noting to signal intensity and signal to noise ratio. quantitative analysis has been at this optimum and 1 atmosphere pressures, resulting in this data that are in good agreements with XRF methods. results also show that the sensitivity and LOD at optimum pressure with respect to atmosphere pressure were improved.