Effect of advanced nanowire-based targets in nanosecond laser-matter interaction (invited)

An experimental campaign aiming to investigate the effects of innovative nanostructured targets based on Ag nanowires on laser energy absorption in the ns time domain has been carried out at the Laser Energy for Nuclear Science laboratory of INFN-LNS in Catania. The tested targets were realized at INFN-Bologna by anodizing aluminium sheets in order to obtain layers of porous Al2O3 of different thicknesses, on which nanowires of various metals are grown by electro-deposition with different heights. Targets were then irradiated by using a Nd:YAG laser at different pumping energies. Advanced diagnostic tools were used for characterizing the plasma plume and ion production. As compared with targets of pure Al, a huge enhancement (of almost two order of magnitude) of the X-ray flux emitted by the plasma has been observed when using the nanostructured targets, with a corresponding decrease of the "optical range" signal, pointing out that the energetic content of the laser produced plasma was remarkably increased. This analysis was furthermore confirmed from time-of-flight spectra.