[en] Nowadays, the level of technological progress, the foundations of which were laid in previous decades, has made it possible to practically master the use of near-earth orbits and conduct separate research trips beyond them. Further steps, including expanding the functionality of space vehicles in near-Earth orbits, the creation and regular operation of a lunar space base, large-scale planetary and other bodies of the solar system exploration, and sounding of deep space, requires, first of all, a sharp increase in the capabilities and efficiency of space transport systems. A further increase in the flow rate of the working fluid requires an increase in its specific energy content, that is, conversion to a plasma state, which is implemented in ion engines. In ion engines, ion beams are accelerated in an electric field organized by electrodes. The volume charge in the accelerating gap is not compensated; this serves as one of the restrictions on the current density in such a beam. In the present work, we took hydrogen, deuterium, helium, nitrogen, argon, krypton, xenon as the working fluid, for which the dependences of the optimal ion emission current density on the distance and voltage between the electrodes of the accelerating gap, breakdown voltage of distance between the electrodes, specific thrust of the specific impulse, specific impulse of the mass number of ions and others were calculated, and the most promising and effective working fluid was determined. (paper)

[en] This work covers a method of non-destructive layer profiling of ultra-thin films on solid. The method is based on solution of the problem of elastic and inelastic photoelectron scattering in multilayer inhomogeneous films. An example of depth profiling of an air-oxidized ultra-thin chromium film on a silicon substrate is given. (paper)