Angular distribution of ejected atoms from Nd : YAG laser irradiating metals

A Nd:YAG pulsed laser is employed to irradiate different metals in vacuum a t the ECLISSE facility of the Laboratorio Nazionale del Sud, Catania, INFN. Laser pulse energy, 9 ns in width, ranges between 100 and 900 mJ. The ejec tion of atoms by means of laser irradiation is studied in terms of angular distribution, laser etching yield and film thickness deposited on a substra te. Light elements (Ni, Cu) show an angular distribution that is larger tha n heavy ones (W, Pb). A theoretical approach, applied to fit experimental d ata, indicates that the distribution depends on the high power of cos theta and that the flow velocity of ejected atom ranges between 27 000 and 88 00 0 m/s and the kinetic energy of ejected species ranges between 0.7 and 4.4 keV. (C) 2001 American Institute of Physics.