الفهرس 
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Abstract
The Laser Ablation technique (LA) is one of the physical methods for creating nanoparticles (NPs) by removing layers from the target by using a pulsed laser. Laser Ablation in Liquids (LAL) is a form of LA. The size and shape of NPs created by LAL are very sensitive to the laser parameters and the type of liquid. LAL is being used to create contaminant-free colloidal NPs with unique properties. Many factors influence the substance’s absorbance of the incident laser beam, which leads to the creation of NPs, as well as the control of size and shape. Among them are laser pulse energy, laser wavelength, ablation times, laser polarization, angle of incidence, and material properties.
In this study, the results of producing silver nanoparticles (Ag-NPs) colloids in distilled water is presented by LA from a bulk silver metal using the 2nd harmonic of Nd: YAG high power laser. The particle size, morphology, and absorption spectrum of the Ag-NPs colloids are derived from the transmission electron microscopy (TEM) and ultraviolet-visible (UV-Vis) spectrophotometer. The TEM of Ag-NPs image shows a like-spherical shape at different ablation times and different pulse energies, whereas at ablation laser pulse energy>100 mJ and when the angle between the laser beam and the silver bulk was changed from 900 to 600, it reveals different nanoshapes.. The Ag-NPs size distribution was found to be shifted to the quantum dots (10 nm) with the increase of the LA time and reach an average size of 7.5 nm at 30 minutes ablation time with laser pulse energy of 100 mJ. Also, in the case of 30 minutes ablation time and laser pulse energy of 100 mJ, the obtained nanoparticles have a size distribution falling into two ranges of 1-10 nm (55%) and 10-20 nm (45%).