21. 11. 2012. Семинар: Jörg Hermann

 

У среду, 21. новембра 2012. године у у 12 сати у сали Звонко Марић Института за физику у Београду одржаће семинар

Dr Jörg Hermann
LP3, CNRS - Aix-Marseille University, Luminy, Marseille, France

Properties of plasmas produced by laser ablation with single and double pulses

Abstract. Pulsed laser ablation has attracted a strongly increasing interest over the past two decades. The advances in the understanding of laser-material interactions as well as the technological progress in compact and reliable laser systems made laser ablation promising for many applications such as thin film deposition, nanostructuring of materials, surface treatment, nanoparticle generation and material analysis. Due to the high power density of focused laser radiation, pulsed laser ablation leads to the formation of a plasma characterized by large initial values of temperature and density. The plume undergoes fast expansion during which the temperature and density rapidly decrease. Recent investigations demonstrated that the irradiation with so-called “double-pulses” may improve the properties of the laser-induced plasmas in the view of different applications. In the present paper, we discuss the physical mechanisms responsible for the plume changes that occur when an additional delayed laser pulse is applied.