Drobnych V. Differential characteristics of excited particles emission under the ion bombardment of metals: methods, experiment, theory.

The dissertation is devoted to investigation of emission of excited particles under the ion bombardment of metal surfaces in vacuum. The new approach (Doppler Tomography) to the investigation of this and related phenomena is developed. Doppler Tomography allows to obtain the exhaustive experimental information on the flux of sputtered, scattered and desorbed atoms and ions by means of separation of the particles by velocity vectors and electron states, including nonstable ones. The theoretical foundations, software applications and apparatus basis of Doppler Tomography were developed. This allowed to obtain the complex of data on the single and three dimensional velocity distributions of excited particles sputtered and scattered under the ion bombardment of metals. It is stated, that in the case of ion bombardment of metals emission of excited atoms essentially differs from the emission of excited ions by their differential characteristics and the regularities of the behavior of the last under the alte ration of experimental conditions. It is showed that this is conditioned by the following difference in the mechanisms of excited neutral and ionized particles emission: the excited ions acquire the excitation in atomic collisions on the surface, they are knocked out at the initial stage of the development of the collision cascades and reflected from the surface as a result of single scattering acts on the surface atoms (when the last are heavier then the bombarding ions), whereas the excited atoms acquire the excitation through the electron exchange mechanisms and the significant part of them are knocked out in the base regime of sputtering of metal, moreover this mechanism becomes the dominating one under the bombardment of the surface along the normal. It is showed that in the case of ion bombardment of metals the mechanism of excitation of emitted atoms is realized mainly through the following processes: resonant and non-resonant single electron transitions between the metal levels and levels of particle, single electron transitions within the particle levels and also Coulomb interaction of the electrons, captured by particle. Accounting of these processes in the quantum-mechanic simulation of the evolution of the multielectron system "metal - emitted particle" allows to explain the experimentally observed efficiency of excitation of secondary atoms and the shape of dependencies of excitation and ionization probabilities of the secondary atoms on their velocities. Two new optical methods of surface diagnostics with ion beams are proposed. One of them is based on the measurement of differential characteristics of the flux of scattered excited particles. It is an optical analog of the known method of spectroscopy of scattered ions. It allows to analyze the first monolayers of the surface. The another method is based on the measurement of both integral and differential characteristics of the flux of secondary atoms, which undergo the excitation by laser radiation with specially selected parameters. The method all ows to carry out the standardfree highsensitive quantitative element analysis of materials.