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Issue 2, 2022

Radiophysics, electronics, acoustics

Acoustic field of a source moving perpendicular and along the interface with a sharp impedance drop

Acoustic field of a source moving perpendicular and along the interface with a sharp impedance drop

Yu. M. Zaslavsky$^1$, V. Yu. Zaslavsky$^{1,2}$

Memoirs of the Faculty of Physics 2022. N 2.

The acoustic field generated by a pulsating source moving in the atmosphere along and perpendicular to the water-atmosphere interface at a subsonic speed is investigated. Calculated relationships are derived for the amplitude, frequency, and duration of a sound pulse recorded in both media in the vicinity of the interface. The spatial distribution of the amplitude of the acoustic field in the atmosphere and in the liquid is presented in the form of a two-dimensional relief to demonstrate its features and dependence on the speed and direction of motion of the sound source. The relationship between the characteristics of acoustic radiation and the average depth in the water area is analyzed.

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Physics of nuclei and elementary particles

Centrality dependence of particle emission in nucleus-nucleus collisions at the nucleon and quark levels

Centrality dependence of particle emission in nucleus-nucleus collisions at the nucleon and quark levels

G. O. Ambaryan$^3$, V. L. Korotkikh$^1$, G. H. Eyyubova$^2$

Memoirs of the Faculty of Physics 2022. N 2.

A theoretical analysis of the particle multiplicity as a function of centrality is made with respect to particle emission sources (wounded nucleons, quarks) in a wide energy range from RHIC to LHC. The Monte Carlo Glauber model is used for heavy ion collisions. It is shown that scaling in terms of the number of wounded quarks is fulfilled at all energies. This effect is associated with an increase of the wounded quarks pairs in the transverse plane with a decrease of the colliding nuclei impact parameter. A wounded quark emits the same number of particles regardless of the colliding nuclei impact parameter.

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Radiophysics, electronics, acoustics

Development of an equivalent circuit of a ring resonator with a working mode of oscillation E020, for use in one-dimensional programs for calculating a multibeam klystron with non-identical electron beams

Development of an equivalent circuit of a ring resonator with a working mode of oscillation E020, for use in one-dimensional programs for calculating a multibeam klystron with non-identical electron beams

R. A. Kosarev$^1$, I. A. Freydovich$^2$

Memoirs of the Faculty of Physics 2022. N 2.

Annotation. The article presents an equivalent circuit of a ring resonator operating on the E020 vibration mode. A comparison of the results of modeling resonators using three-dimensional programs of electrodynamic modeling (CST Studio Suite) and using an equivalent circuit is carried out. The equivalent circuit is based on the idea of a ring resonator as a waveguide rolled into a ring. The electromagnetic field in a waveguide is described using an equivalent long line. The equivalent circuit is intended for use in programs for calculating the parameters of a klystron with non-identical conditions for the interaction of electron beams.

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Physics of Earth, atmosphere, and hydrosphere

Study of the albedo of marble and sand

Study of the albedo of marble and sand

B. M. Ibrahim$^1$, Yu. P. Pyt'ev$^2$, A. A. Samah$^1$, O. V. Falomkina$^2$

Memoirs of the Faculty of Physics 2022. N 2.

In this paper, the intensity of solar radiation incident and reflected from the surfaces of marble and sand is studied in detail. The albedo values of these surfaces are calculated on the basis of radiation intensity measurements performed using a luxmeter. The measurements were carried out for marble and sand surfaces during two days of the summer months at two points in the vicinity of Baniyas on the Mediterranean coast in the province of Tartus, in Syria: in the town of Alqurdiye and at the station "Baniyas". The albedo values are calculated based on the measurement results. The results are compared, graphical curves are constructed that reflect the changes in albedo depending on time.

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