Laser-induced breakdown spectroscopy system (LIBS) had been designed to the determinate of the best ionization laser power for analysis of the writing inks via analysis induced plasma emission. Passively Q-Switched Nd:YAG laser at the fundamental wavelength 1064 nm with different energies (60 mJ,80mJ, 100 mJ, 200 mJ, 300mJ, 400mJ and 500 mJ) with (10 ns) pulse duration, the laser beam was focused via converging lens with focal length (100 mm) that generates different power intensity, optical spectrum analysis system used was within (Si-CCD) array detector, within spectrum range of (200 - 900 nm) with (0.8 nm) optical resolution. Use A4 sheets of commercially available standard white office paper with 2 Ballpoint pens and 1 Gel pen as samples. Show the results that the laser energy (80 mJ) with ( power density, was the best power to generate plasma homogeneous for all component writing inks and ionize it without effect on the paper material. Keywords: LIBS, Laser intensity, Writing inks, White paper, plasma emissions lines, emission line analyses DOI: 10.7176/CPER/61-05 Publication date: July 31st 201
