Особенности возбуждения линий главной серии атомов подгруппы цинка электронным ударом. II. Цинк

Using the technique of crossed beams of slow electrons and zinc atoms, the excitation functions of four spectral lines of Zn I principal series corresponding to the 4snp 1Po1  4s2 1S0 transitions for n = 4, 5, 6, 7 are measured. Their wavelengths are 213.9, 158.9, 145.8, 140.4 nm, respectively. In the energy range 11–18 eV, these functions revealed the manifestation of the effect of collision interaction of electrons (slow scattered and fast emitted) during the decay of the autoionization state. At incident electron energies of 11–13 and 15–18 eV, this interaction leads to an additional population of the initial levels for these lines and, correspondingly, to the formation of maxima on their excitation functions due to the capture of the scattered electron at the indicated excited levels. The terms of autoionizing states of the atom responsible for the observed maxima are established. The combined effect of the decay of these autoionizing states and the post-collision interaction is expressed in the energy shift of the maxima on the excitation functions relative to the positions of the corresponding autoionizing states. In the classical approximation, the effective widths of the electronic decay of autoionizing states are estimated by direct calculations. For the estimations, exact and approximate formulas are used. The latter are valid for various relations between the magnitude of the post-collision shift of the maxima on the excitation functions and the electron binding energy at the atomic level. They are used to determine the effective widths when the experimental shifts are approximated by the least squares method.

Особенности возбуждения линий главной серии атомов подгруппы цинка электронным ударом. I. Кадмий

Using the technique of crossed beams of slow electrons and cadmium atoms, the excitation functions of three spectral lines of its principal series (166.9, 152.7, 146.9 nm) outgoing from the 5snp 1Po1 levels were measured (n = 6, 7, 8, respectively). In the range of electron energies 12–18 eV, a manifestation of the post-collision interaction of slow scattered electrons and fast electrons ejected during the decay of autoionizing states was found in these functions. This process, at incident electron energies of 11.8, 12.4, and 16.6 eV, leads to additional population of the initial levels of spectral transitions and, correspondingly, to maxima on the excitation functions due to the capture of a scattered electron to these excited levels. The terms of autoionizing states of the atom responsible for the observed maxima on the excitation functions of spectral lines are established. In the classical approximation, by two methods – direct calculation and least squares approximation – estimate the effective widths of the electronic decay of autoionizing states, the combined action of which leads to an energy shift of the maxima. Approximate calculation formulas are used, which are valid for various relations between the post-collision shift of the maxima on the excitation functions and the binding energy of atomic levels.

EXPERIMENTAL INSTALLATION FOR RESEARCH OF PHOSPHORS LUMINESCENCE EXCITATION, STIMULATION AND EXTINGUISHING BY ATOMIC AND MOLECULAR BEAMS

Gas plasma technologies are becoming increasingly important on an industrial scale. They contribute to the production and processing of materials using the heating of the initial products in the plasma jet or their transfer to the plasma state. Therefore, the main goal of the work is to study the efficiency of an experimental setup for studying the excitation of stimulation and quenching of phosphorus luminescence in atomic-molecular beams. To achieve this goal, we analyzed the dissociation of gases in a high-frequency inductive discharge in the main circuits of modernized generators. The article presents the design, construction, hardware of the installation for the study of excitation, quenching and stimulation of the crystal phosphors by various methods when exposed to their surface single or crossed beams of gas molecules and atoms of thermal energy. Fragments of the kinetics and photoluminescence spectrum of yttrium oxide doped with europium in the beam of oxygen atoms were established.

Optimal Design of Grillage Structures with Steel Crossed Beams using Genetic Algorithms

The optimal problem in the structural design is an important issue in the engineering design. Various authors have analyzed the optimization of steel structures using algorithmic approaches. These techniques are generally grouped in deterministic or meta-heuristic techniques. From the introduction of structural optimization in the 1960’ up to now, various methods have been proposed. A genetic algorithm, is built and applied in this study using MatLab soft R2017a to a crossed beams system. The structural analysis is done with the direct stiffness method with constraints verification based on EuroCode 3:2005 criteria. Results are reported in the study.