[en] The experimental and theoretical data on energy distributions of reflected hydrogen atoms are compared with computer simulations based on BCA Monte Carlo code. It is shown that analytical theories fail to describe the dependence of energy spectra parameters on the angle of incidence for small angle scattering of the beam at the energy about few tens of keV. The computer simulations reasonably agree with experimental data. The restriction in computation of the maximum value of scattering angle in each collision results in good agreement of energy spectra of reflected particles with an analytical model

[en] A computer code incorporating real surface reliefs for calculations of integral and differential parameters of particle reflections from solids is briefly described and validated by comparing with experiments and known analytical solutions for ideally smooth surfaces. Calculations of the angular distributions of deuterons reflected from rolled SS surfaces and grinded W samples show differences depending on the angle of irradiation relative to the direction of the relief structure. A comparison of calculations with experimental data on 100 eV deuteron reflection from grinded W shows reasonable agreement for the experimentally investigated interval of angles. Some new features of angular distributions in the plane of incidence and in the perpendicular plane are found. So, the possibility of more accurate account of reflected particles contributing to hydrogen recycling near real PFC of fusion devices is demonstrated

No abstract available

[en] Investigations of the influence of carbon and hydrocarbon layers on the trapping and reflection of hydrogen isotopes by tungsten were carried out with BCA based computer code SCATTER. It is shown that for small layer thickness the trapping efficiency depends on the hydrocarbon film composition. At layer thickness of a few nanometers energy dependence of the trapping efficiency has a non-monotonous character with a minimum at primary energies about 100-1000 eV and continuous increment with energy at higher energies. The possible reason of this effect is briefly discussed. Comparison between the trapping efficiencies of different hydrogen isotopes in a C-W target is also presented

[en] Two mechanisms of the recoil sputtering are investigated. The first one is connected with recoils generated by the inward flux of incoming ions while the second one - with those generated by the backward flux of ions reflected from the bulk of the target. It is shown analytically that the ratio of the yields given by the two mechanisms is equal to 2 and does not depend on the energy and direction of the recoil emission, the angle of incidence and energy of primary ions, the atomic masses of the projectile and the target atom. Computer simulations for 1-30 keV Ar ions incident on Pt target at grazing angles are rather in good agreement with the analytical theory

No abstract available

[en] The features of changing the energy spectra of particles reflected from Mo target at small angle scattering of molecular and atomic ions of hydrogen isotopes in the energy range of 1-30 keV are studied. The clearly expressed maximum with the considerable spectra broadening in the range of low energy are observed on energy dependencies of the relative half-width of energy spectra of particles reflected from a molybdenum target for protium and deuterium. This peculiarity is explained by means of the simple model of the Coulomb dissociation of molecular ions falling on the target. The expression for spectra broadening at the expense of the molecular effect for heteronuclear ions falling on the target is presented as well as the comparison of theoretical and experimental is fulfilled

No abstract available

[en] Modeling of argon cleaning of tungsten coated by carbon film was performed taking into account the back flux of carbon. The rise of the argon energy from 200 to 1000 eV accelerates the tungsten surface cleaning. Increase of the carbon flux on the surface does not change the character of the cleaning but decreases it rate

No abstract available