الفهرس 
Cover EnglishOnly 14 pages are availabe for public view
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Abstract
One of the most important aspects in laser cleaning of artworks is the possibility for monitoring and controlling the cleaning process. This ensures that the cleaning intervention is satisfactory without any damage to the underling original surface. In this work, two lasers have been employed for laser cleaning test, Q-switched ns mode and short free running μs mode. Optical pulses generated by Nd: YAG lasers are used to probe the high absorbing layer of crust from surface of a lower absorbing marble substrate. The cleaning tests on marble proved the prospective of introducing plume-imaging technique as straightforward and inexpensive tool for the determination of the critical point for a safe surface cleaning. The potential of plume imaging has been investigated as a real time monitoring technique for the control of laser cleaning processes of cultural heritage objects with emphasis on encrusted stonework. The new technique of plume imaging that based on the Coupled charge Device (CCD) camera has been exploited to follow up the emitted plume intensity from the irradiated surface. Thus, the intensity of the emitted plumes that can be changed from layer to layer is used to monitor the cleaning of stones. This technique makes it possible to determine at what laser pulse the substrate of marble is reached. Laser induced breakdown spectroscopy (LIBS) is also employed to study the stratigraphy of the encrusted marble. LIBS technique is used to provide an advantageous methodology as it offers a reliable instant response and simultaneously may give important stratigraphy information. LIBS measurements have been performed by the fundamental wavelength (1064 nm) of Nd: YAG laser for the elemental analysis and performing the cleaning processes of ancient Egyptian pottery. Different analytical ii techniques such as X-Ray Diffraction (XRD), Scanning Electron Microscopy and Energy Dispersive X-Ray analysis (SEM-EDX) have been used in the present work to provide important physical and chemical insight to the structure of the samples. A complementary study is used to perform the morphological surfaces before and after cleaning by Optical Microscopy (OM). The analytical study demonstrates the potential of LIBS technique for performing rapid on site analysis of archeological pottery which leads to quick characterization and mapping of the samples.