The knowledge that has been developed for the ICF modellingis applied in the domain of laser processing of various materials and for improving the technology of processes assisted by laser.
Metal ablation by ultra short laser pulses
We have developed an evolution model that allows one to calculate the flux of ejected matter in the low intensity regime, near the ablation threshold. It takes into account the non-equilibrium phase transition, plasma recombination, recondensation of vapours and fragmentation of shocked liquid layers. It was demonstrated that micrometric particles in the ablated matter are originated from the liquid phase fragmentation and the nanoparticles could be generated by vapour condensation in the nucleation process. The theoretical model has been compared with the results of experiments carried out at CELIA in collaboration with SXP group. The research studies in this direction were further developed with the PEPSI group. We analyzed the damages generated in optic elements located in the LMJ experiment chamber by the target remnants after the laser shot. More recently another experiment on the optical damage has been conducted on the Alisé laser at CESTA.
Formation of cavities, liquid jets and contribution to the Laser Induced Forward Transfer
Nanocavity formation in silica and water by tight focusing of intense femtosecond laser pulses has been studied with a recently developed numerical model. The modelling results are compared with experimental results obtained in collaboration with E. Gamaly (ANU) and S. Juodkazis (Hokkaido University). The equation of state for water in the low temperature regime has been developed in collaboration with the CEA/CESTA. These studies are extended to the laser interaction with transparent materials in a confined geometry. It is demonstrated with numerical simulations that nanometric jets could be generated in some specific conditions, even in solid materials. This work is conducted in support of experiments of our colleagues from INSERM (U577) in Bordeaux.