HIGH POWER TW/PW LASER IRRADIATION

摘要

The present invention refers to the method used to form diamond nano-sized structures on certain substrates made from interest materials for nuclear fusion using lasers in impulses. The present invention uses short laser beams (fs, ps) produced with a repetition rate of 1- 10 Hz, and wavelength from around 750 nm until around 850 nm, the most frequent at a frequency of 800 nm in vacuum or gaseous atmosphere (air or deuterium).;The mixed films containing Be, C, W were obtained using the thermionic vacuum arc method (TVA). These films have thicknesses of 0.1 - 10 µm and interact directly with single or multiple laser beams as well as with the plasma produced by indirect laser beam irradiation in ambient gases as air or deuterium. The laser pulses produce diamond or fullerene nanostructures on the irradiated mixed materials surface.;By this method, the irradiated material is processed in a non-thermal mechanism. Multiphotonic interactions and collision ionizations combination creates plasmas in the impact areas of shorter term than the kinetic electron energy that can be transferred in the material. The produced plasma is not in thermal equilibrium, the irradiated material being changed from initial solid state in totally ionized plasma in such a short time that the thermal equilibrium can not be reached. As a result, a negligible thermal transfer to the layers outside the interaction area occurs. The transition of this non-thermal regime to the thermal regime depends on the irradiated material and it is in the range 1 to 20 ps. Due to the fact that the unexposed area heating is negligible, the adjacent material composition is substantially unaffected by the irradiation process proposed in the present invention.