<title>Selection of radiation parameters of lasers used for artwork conservation</title>

Abstract

The study of the interaction of high power lasers with a solid-state matter is as old as the laser itself. The processes in which dominate ablation depend primarily on the laser power density and wavelength. Cleaning of surfaces of historical objects and artworks with pulsed laser radiation is an universal technique. However, it requires high precision in selection of parameters of pulsed laser radiation particularly for cleaning of unique artworks. The paper presents influence of laser radiation parameters on velocity of encrustation removal from artworks and heritage architectural objects. The influence of laser fluence, pulsewidth and pulse repetition rate on parameters of graphite layer ablated from aluminium substrate (temperature, pressure density and velocity of removal) is discussed on the basis of developed numerical model. In conclusion, selected experimental results of influence of laser wavelength and fluence on velocity of encrustation removal for different heritage objects are given as well as remarks on laser cleaning process are presented.