Issue 6, 2025

Space-like pion off-shell form factors in the Bethe-Salpeter approach

S. G. Bondarenko$^{1,2}$, M. K. Slautin$^{1,2}$

In the paper, the off-shell electromagnetic pion form factors in the Bethe-Salpeter formalism are considered. The separable kernel of the first rank quark-antiquark interaction is used to solve the equation analytically.The semi-off-shell pion form factors 𝐹1 and 𝐹2, which are related to each other by the Ward-Takahashi identity, are calculated. The obtained off-shell form factors as well as static properties of the pion are compared with the results of other authors

$B^- \rightarrow \mu^+ \mu^- e^- \bar{\nu}_e$ decay in orthogonal amplitudes method

D. S. Ostapovich

In the present paper partial widths and differential ditributions of $B^- \rightarrow \mu^+ \mu^- e^- \bar{\nu}_{e}$ and $B^- \rightarrow e^+ e^- \mu^- \bar{\nu}_{\mu}$ decays were calculated, utilizing the orthogonal amlitudes method. Virtual photon emission by the light quark (VMD model), virtual photon emission by the heavy quark and bremsstrahlung were accounted for in calculations. The results obtained are in a satisfactory agreement with experimental constraints.

Определение характеристик пластиковых сцинтилляционных детекторов

P. G. Filonchik$^{1,2}$, D. N. Grozdanov$^{2,3}$, Yu. N. Kopach$^2$, P. S. Prusachenko$^2$, N. A. Fedorov$^2$, I. N. Ruskov

В Объединённом институте ядерных исследований (ОИЯИ) в Лаборатории нейтронной физики им. Франка (ЛНФ) в группе TANGRA проводится эксперимент по исследованию угловых корреляций в реакции неупругого рассеяния нейтронов с энергией 14,1 МэВ на ядрах углерода. Для регистрации нейтронов использовались 10 длинных (1 метр) пластиковых сцинтилляционных детекторов производства компании EPIC CRYSTAL. Их особенностью является наличие двух фотоэлектронных умножителей (ФЭУ), благодаря чему они обладают позиционной чувствительностью. В настоящей работе были выполнены измерения характеристик этих детекторов: пространственное разрешение и коэффициент затухания.

The effect of the addition of neptunium on the duration of the fuel campaign in the BN reactor

V. A. Pavlovich, M. A. Kharkov, V. O. Skulkin

The aim of the work is to evaluate the possibility of using neptunium as fuel for the BN-600 reactor and its subsequent effect on the length of the fuel campaign. To carry out the calculations, neutron physics and thermophysical models of fuel assemblies of reactors were created. Neptunium was added to the main fuel homogeneously in various proportions ranging from 1 to 20% in the form of NpO2 oxide. The characteristics under consideration are the neutron multiplication coefficient in an infinite medium, and the spatial temperature distribution in the fuel element. The homogeneous addition of neptunium to the fuel has a negative effect on Keff. Adding a fraction of neptunium oxide of more than 5% is impractical. The addition of neptunium also had a negative effect on the energy release values, but to a lesser extent. When neptunium is added, the temperature of the BN-600 fuel rods changes by 2-3% at the fuel assembly inlet and outlet.

S. A. Kotov, Z. V. Naumova, T. S. Kudryavtseva, V. V. Davydov, O. I. Suchkova

One of the tasks of applied physics is to develop new methods for the use of condensed media, which are waste from various industries. In this case, several problems are solved, both related to ecology in its various applications, and to the production of various elements using physico-chemical processes. The paper considers rolling scale, which is formed in large quantities during the operation of metallurgical enterprises. One of the possible options for recycling rolled scale (recycling) is related to the possibility of its use as a sorbent in liquid purification and filtration systems. Morphological, chemical, and phase features of rolled scale are considered to determine its potential for sorption activity. Using spectral studies, a comparative analysis of magnetic and non-magnetic fractions was carried out, and differences in the content of iron-containing phases and impurity elements were revealed. It is established that the microstructure and composition of the material are determined by the conditions of its formation and directly affect the adsorption characteristics. The presence of magnetite and a porous structure contributes to the formation of an active surface for the deposition of chemically active elements on it, such as phosphorus, zinc and other dangerous elements that are not removed by mechanical filtration.