Dependence of Sputtering Coefficient on Energy and Incidence Angle of Bombarding Particles. Energy Spectrum and Average Energy of Sputtered Particles by the Example of a Tungsten Target

An overview of the functional dependences (formulas) for describing the properties of atomic particles sputtered during ion bombardment of the surface of a solid body is presented. The dependence of sputtering coefficients on the energy and angle of incidence of the bombarding particle is considered. The energy spectra and average energies of sputtered particles are presented. Formulas for calculating the quantities under consideration are proposed by the example of a target made of tungsten and hydrogen isotopes as projectiles. These data are necessary to estimate the entry of sputtered tungsten atoms as an impurity into a hot plasma using transport codes. When the tungsten impurity concentration is higher than the critical one, it is impossible to carry out a controlled thermonuclear reaction with the planned energy output in the ITER tokamak reactor. Sputtering coefficients also play an important role in simulating the entry of impurities into plasma facilities as a result of the interaction between hydrogen fuel atoms and the materials of the divertor and the first wall.