Laser heating and ablation at high repetition rate in thermal confinement regime

• Published in: Applied surface science 2006-09, Vol.252 (23), p.8314-8318
• Main Authors: Brygo, François, Semerok, A., Oltra, R., Weulersse, J.-M., Fomichev, S.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; High repetition rate; Impact phenomena (including electron spectra and sputtering); Insulators; Laser ablation; Laser heating; Laser-beam impact phenomena; Modelling; Physics; Radiation effects on specific materials; Structure of solids and liquids; crystallography; Thermal confinement regime
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2005.11.036

Laser heating and ablation of materials with low absorption and thermal conductivity (paint and cement) were under experimental and theoretical investigations. The experiments were made with a high repetition rate Q-switched Nd:YAG laser (10 kHz, 90 ns pulse duration and λ = 532 nm). High repetition rate laser heating resulted in pulse per pulse heat accumulation. A theoretical model of laser heating was developed and demonstrated a good agreement between the experimental temperatures measured with the infrared pyrometer and the calculated ones. With the fixed wavelength and laser pulse duration, the ablation threshold fluence of paint was found to depend on the repetition rate and the number of applied pulses. With a high repetition rate, the threshold fluence decreased significantly when the number of applied pulses was increasing. The experimentally obtained thresholds were well described by the developed theoretical model. Some specific features of paint heating and ablation with high repetition rate lasers are discussed.