Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Physics

A comparative study of the plasma produced from irradiated nano- ZnO and the corresponding bulk targets was conducted via OES- technique. A pulsed Nd:YAG laser working at the fundamental wavelength of 1064 nm was utilized to irradiate both targets under the same experimental conditions in open air. The laser fluence was detuned in the range from 33.2 J/cm2 down to 2.5 J/cm2 keeping spot size fixed at 0.9 ± 0.1 mm as well as both of gate and delay times at the level of 1 {uF06D}s. The spatially integrated amount of emitted light from either plasma under the different experimental conditions were analyzed and recorded using an Echelle type spectrograph in conjunction with a time gated ICCD camera. Moreover, the plasma temporal profile was monitored at a different delay times ranging from 1 to 7 {uF06D}s at a fixed gate and laser fluence values. The LIBS analysis utilizing the Zn I-lines was carried out at the wavelengths of 328.26, 330.29, 334.55, 468.06, 472.2, 481.01, and 636.38 nm. An apparent enhanced emission from Zn I-lines emerged from the nano-target based plasma over the bulky one, was noticed and studied in terms of the recommended plasma parameters namely electron density, temperature and relative concentration of the present element

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