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The impact of ionizing radiation on space technology

Change in glass K-208 morphology upon irradiation with medium-energy electrons

Change in glass K-208 morphology upon irradiation with medium-energy electrons

A. I. Ustinov

Memoirs of the Faculty of Physics 2021. N 3.

The results of AFM-researches of the glass K-208 samples are presented surfaces irradiated with electrons with energies of 20÷50 keV at a particle flux density φe = 3,0•1010 ÷ 1,0•1011 cm –2s–1. The samples were irradiated in a vacuum chamber at pressure of 10–4 Pa. Shown that changes in morphology of glass K-208 upon irradiation with medium-energy electrons occur due to electrostatic discharges, which resulted in forming microprotrusions and discharge channels, as well as due to forming of gas-filled bubbles.

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Influence of electron irradiation on the weight loss of a polymer composite and its contam-ination by gas release products of the optical glass surface

Influence of electron irradiation on the weight loss of a polymer composite and its contam-ination by gas release products of the optical glass surface

V. K. Meleshko, I. B. Vintaykin

Memoirs of the Faculty of Physics 2021. N 3.

In our work, we present the results of computational and experimental studies of the deposition of gas release products and radiation sputtering of a polymer composite material on the surface of cover glass samples of solar cell elements of a spacecraft under electron irradiation. K-208 glass samples were exposed to electrons with an energy of 30 keV and volatile products released from the EKOM-1 material when heated or under the action of electrons. The average electron flux density was cm-2 s-1, and the pressure in the vacuum chamber did not exceed Pa. Contamination of glass surfaces was controlled by measuring the transmittance of glass samples. The measurements were carried out on a «Cary 500» double-beam spectrophotometer in the range from 200 to 3300 nm with a spectral resolution of 2 nm. The measurement results showed that the largest decrease in the spectral transmittance of glass samples occurred after the simultaneous exposure to electron radiation and molecular fluxes. It was founded experimentally that irradiation of glass with electrons leads to an increase in the rate of accumulation of gas release products on it. This is due to the electrification of glass, which stimulates the deposition of radiation-ionized drugs on it - products of gas release and sputtering of EKOM-1.

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Mechanisms of interaction of the recharging plasma of an electric rocket engine with a radiation-charged dielectric surface

Mechanisms of interaction of the recharging plasma of an electric rocket engine with a radiation-charged dielectric surface

V. V. Valiullin, A. B. Nadiradze

Memoirs of the Faculty of Physics 2021. N 3.

In this paper, an attempt is made to develop a mathematical model of the interaction of the recharge (low-temperature) plasma of an electric rocket engine with a radiation-charged dielectric surface. This model is based on the well-known Fitting dielectric charging model, which describes the transport of non-equilibrium charge carriers in the near-surface layer of the dielectric. Possible physical processes of interaction of ions of the recharge plasma of an electric rocket engine with a radiation-charged dielectric surface are considered. It is shown that as a result of all these processes, holes are formed in the surface layer of the dielectric, on which the excess electrons are then relaxed.

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Medical physics and radiation technologies

Generation of a sterilizing aerosol jet based on a gliding arc electric discharge

Generation of a sterilizing aerosol jet based on a gliding arc electric discharge

N. A. Aristova$^1$, A. A. Makarov$^2$, N. K. Gulko$^2$, I. P. Ivanova$^3$, I. M. Piskarev$^4$

Memoirs of the Faculty of Physics 2021. N 3.

The redox properties of liquids treated by a gliding arc electric discharge have been investigated. Distilled water and aqueous solutions of hydrogen peroxide with a concentration of 0.2 and 0.5% were used as working liquids. For the analysis, the sediment of aerosol mixture was caught. To determine the oxidation yield, the reaction of the sediment sample with a solution of Mohr's salt was used. The reduction yield was determined in the reaction with KMnO4. It was found that distilled water after passing through the discharge region acquires oxidizing properties. The oxidizing properties of hydrogen peroxide solutions are significantly enhanced. The oxidation yield is in the range of 2.2 – 4.8 (100 eV)1, the reduction yield is small, does not exceed 0.1 (100 eV)1. In the reaction with methyl orange (MO) concentration of 8 mg/L, the oxidizing ability of 3% hydrogen peroxide and the discharge-treated liquid are compared. It is shown that the liquid treated by the discharge almost completely oxidizes the MO solution, while 3% hydrogen peroxide has no effect on the MO. The main product formed under the action of a discharge in an aerosol flow is a complex that decomposes by ~95% within a time period of up to 3 days. Decomposition products are peroxynitrite and peroxynitrous acid. Their oxidative potential is much higher than that of chlorine and hydrogen peroxide. Therefore, the aerosol jet that has passed the gliding arc discharge area can be used as a strong disinfectant. This product is environmentally friendly, as active species decompose into water, nitrogen and oxygen.

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High energy physics

SIMULATED ANALYSIS OF JET CHARGE IN PP-COLLISIONS AT THE LHC

SIMULATED ANALYSIS OF JET CHARGE IN PP-COLLISIONS AT THE LHC

I. A. Kochergin

Memoirs of the Faculty of Physics 2021. N 3.

The study of jets charge is necessary to refine the theory of fragmentation in quantum chromodynamics. Also, it can provide an opportunity for improving identification methods in high-energy particle collisions. At the same time, there is a lack of data on jets from heavy flavors. The paper analyzes the weighted charge of the jets from $b$-quarks depending on the method for determining the jet and the method for calculating the electric jets charge by software simulation using the Monte Carlo generator PYTHIA 8.2. Correlations have been established between the type of $B$-meson, type $b$ or $\bar{b}$ quark, and the electric charge of the jet at certain parameters of jet separation and calculation of its charge.

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Nuclear physics

Isospin splitting of the giant dipole resonance of atomic nuclei

Isospin splitting of the giant dipole resonance of atomic nuclei

I. M. Kapitonov

Memoirs of the Faculty of Physics 2021. N 3.

A simple estimate of the magnitude of the isospin splitting of the giant dipole resonance of atomic nuclei based on the concept of isospin symmetry of the nucleon-nucleon interaction is proposed. The obtained value of this splitting exceeds that traditionally used and better describes the experimental data for heavy nuclei.

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Ground State Multiplets with Seniority 2 in Neutron-rich Isotopes of Nickel

Ground State Multiplets with Seniority 2 in Neutron-rich Isotopes of Nickel

D. S. Zhulyaeva$^1$, S. V. Sidorov$^1$, T. Yu. Tretyakova$^{1,2}$

Memoirs of the Faculty of Physics 2021. N 3.

This paper considers neutron pairing interaction in even neutron-rich nickel isotopes $^{70-76}$Ni. The model of zero-range pairing forces is used to study the formation of ground state multiplets with seniority $\nu = 2$ as neutron $1g_{9/2}$ is gradually filled. Mass relation based on masses of four neighbouring nuclei is shown to yield satisfactory splitting of the ground state multiplets, as well as reproduce high-spin excited states in the isotopes under consideration.

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