A test experiment on determining the cluster structure of highly excited states of $^6$Li
A test experiment on determining the cluster structure of highly excited states of $^6$Li
M. V. Mordovskoy, A. A. Kasparov, A. A. Afonin, V. P. Zavarzina, A. S. Kurlovich, V. V. Mitcuk, I. V. Surkova
The paper presents the results of test measurements to determine the possibilities of studying the cluster structure of highly excited states of the 6Li nucleus in the 6Li(n,3He n)3H reaction on the RADEX neutron channel of the Institute for Nuclear Research of the Russian Academy of Sciences. In the experiment, scattered neutrons were detected in coincidence with the decay products of highly excited states (helium-3). The first experimental data on the excitation energy of the 6Li nucleus have been obtained.
Show AbstractCross sections of partial photoneutron reactions: problems of reliability and new data
Cross sections of partial photoneutron reactions: problems of reliability and new data
A. I. Davydov$^1$, V. V. Varlamov$^2$, V. N. Orlin$^2$
The ($\gamma, 1n$), ($\gamma, 2n$), ($\gamma, 3n$) reactions cross sections the majority of which were obtained using beams of quasimonoenergetic annihilation photons were discussed. The significant systematic uncertainties of the experimental results far exceeding the achieved statistical accuracy were considered. The results of experiments for about 50 nuclei from $^{51}$V to $^{209}$Bi were analyzed using objective physical criteria of data reliability. It was shown that in many cases the systematic uncertainties of experimental cross sections were significant and data do not satisfy physical criteria. The experimental-theoretical method for evaluation of cross sections satisfying those criteria was described. The systematic uncertainties of several types due to shortcomings of the method of photoneutron multiplicity sorting used in experiments and specific features of neutron detectors used. The new evaluated reliable cross sections of the partial reactions and total photoneutron reaction $(\gamma, 1n)+(\gamma, 2n)+(\gamma, 3n)$ were presented.
Show AbstractOn the program of photonuclear research using the backward Compton quasi-monochromatic $\gamma$-quanta with tunable $E_\gamma$≲40 MeV
On the program of photonuclear research using the backward Compton quasi-monochromatic $\gamma$-quanta with tunable $E_\gamma$≲40 MeV
S. S. Belyshev$^1$, V. V. Varlamov$^2$, L. Z. Dzhilavyan$^3$, A. A. Kuznetsov$^{1,2}$, A. M. Lapik$^3$, A. L. Polonski$^3$, A. V. Rusakov$^3$, V. I. Shvedunov$^2$
Based on the analysis of development of photonuclear reaction studding at $E_{\gamma}≲40$ MeV and the unique parameters of the Compton source of ${\gamma}$-quanta under projecting, a program of priority photonuclear research using this source is proposed. The program includes research on: structures of giant E1 resonances and pygmy resonances; cross sections for partial photonucleon reactions; nuclear resonant fluorescence; photofission; problems of astrophysics and nucleosynthesis
Show AbstractOn monitoring on the under-development $\gamma$source based on backward Compton scattering for photonuclear research at $E_{\gamma}$ ≲ 40 MeV
On monitoring on the under-development $\gamma$source based on backward Compton scattering for photonuclear research at $E_{\gamma}$ ≲ 40 MeV
S. S. Belyshev$^1$, V. V. Varlamov$^2$, D. L. Zavenovich$^3$, A. A. Kuznetsov$^{1,2}$, A. M. Lapik$^3$, A. L. Polonski$^3$, A. V. Rusakov$^3$, V. I. Shvedunov$^2$
Based on a comparison of the parameters of the projected $\gamma$-source from back Compton scattering and the known ways of monitoring the beams of $\gamma$-quanta themselves to monitor the intensity and energy spectrum of $\gamma$-quanta in their beams at this $\gamma$-source in photonuclear studies in the region from several MeV to ~40 MeV, a system of scintillation plastic and inorganic detectors, as well as a pair magnetic spectrometer, was proposed.
Show AbstractQuestions of mathematical modelling in the study of acid retardation on ion–exchange resins
Questions of mathematical modelling in the study of acid retardation on ion–exchange resins
M. A. Kaznacheev
In this paper, the chemical equilibrium of a multicomponent solution is considered in detail as part of a dynamic model of the acid retardation method. A detailed study of the chemical equilibrium, represented as a system of nonlinear equations, is a key step for building an effective dynamic model in the case of a multicomponent solution. This paper presents an algorithm for efficient calculation of chemical equilibrium using extractive phosphoric acid as an example. This algorithm can be used in a dynamic model to calculate chemical equilibrium at each point of the spatial grid and at each integration step. Moreover, for the concentrations of substances in the experiment on the purification of extractive phosphoric acid, it is shown that the nonlinear system of equations of chemical equilibrium allows one to obtain simple algebraic relations for the connection of the concentration of molecules of the substance with the total concentration of substances of all elements in solution with good accuracy. In addition, it was shown that for each metal, only one type of salt sorption can be considered due to the low concentration of other types, which makes it possible to reduce the number of differential equations in the dynamic model of the acid retardation method.
Show AbstractGap recovery in the time series of CO$_2$ concentration and air temperature using methods of mathematical statistics
Gap recovery in the time series of CO$_2$ concentration and air temperature using methods of mathematical statistics
V. S. Aleshnovskii$^1$, A. V. Bezrukova$^2$, V. K. Avilov$^3$, V. A. Gazaryan$^{1,4}$, J. A. Kurbatova$^3$, O. A. Kuricheva$^3$, A. I. Chulichkov$^{1,5}$, N. E. Shapkina$^{1,6}$
The article is devoted to the problem of recovering gaps in the data series of experimental long-term continuous high-frequency observations of carbon dioxide concentration and air temperature. The study was carried out on the example of the results of observations of an automatic ecological and climatic station located in a tropical monsoon forest on the territory of south Vietnam (Dong Nai Nature Reserve). Omissions in the series of observations, as a rule, are random and are caused by technical malfunctions of the instrument base. Correctly recovered series of observations allow us to estimate the temporal variability of the observed parameters on different time scales. Within the framework of this study, options for recovering the continuity of time series based on the methods of mathematical statistics - autoregression (ARIMA) and the method of linear prediction were considered. A comparative analysis of the accuracy of restoring omissions by various methods is given.
Show AbstractOn the study of reaction yields of $^{13}$C($\gamma$, p)$^{12}$B, $^{14}$N($\gamma$, 2p)$^{12}$B, $^{14}$N($\gamma$, 2n)$^{12}$N through measurements of ($^{12}$B, $^{12}$N) activities with $\Delta E$-detector telescopes between electron accelerator pulses
On the study of reaction yields of $^{13}$C($\gamma$, p)$^{12}$B, $^{14}$N($\gamma$, 2p)$^{12}$B, $^{14}$N($\gamma$, 2n)$^{12}$N through measurements of ($^{12}$B, $^{12}$N) activities with $\Delta E$-detector telescopes between electron accelerator pulses
S. S. Belyshev$^1$, L. Z. Dzhilavyan$^2$, A. I. Karev$^3$, A. M. Lapik$^2$, A. L. Polonski$^2$, V. N. Ponomarev$^2$, A. V. Rusakov$^2$, A. A. Turinge$^2$
The possibilities are analyzed for studying the yields of reactions $^{13}$C($\gamma$, p)$^{12}$B, $^{14}$N($\gamma$, 2p)$^{12}$B, $^{14}$N($\gamma$, 2n)$^{12}$N by measuring the induced ($^{12}$B, $^{12}$N)-activity with telescopes of thin $\delta E$-detectors in time intervals between electron accelerator pulses. For production of ($^{12}$B, $^{12}$N)-nuclei and registration of their decay, estimates are given taking into account the parameters of the electron beam, Ta-radiator and irradiated targets made from graphite or NH$_4$NO$_3$, as well as the parameters of scintillation $\delta E$-detector telescopes made from thin plastic plates.
Show AbstractOn the probable interpretation of anticorrelation between the proton temperature and density in the solar wind
On the probable interpretation of anticorrelation between the proton temperature and density in the solar wind
Yu. V. Dumin$^1$, A. T. Lukashenko$^2$, L. M. Svirskaya$^3$
The anticorrelated distributions of temperature and density of protons are a well-known property of the solar wind. Nevertheless, it is unclear till now if they are formed by some kind of the universal physical mechanism? Unfortunately, a straightforward comparison of the characteristic relaxation times for temperature and density, on the one hand, and pressure, on the other hand, encounters the problem of inapplicability of the hydrodynamical approach in the situation when the free-path length of protons is considerably greater than the spatial scale of the structures under consideration. To resolve this problem, some kinds of the MHD turbulence - reducing the effective free paths - are usually assumed. In the present paper, we use an alternative approach based on the electrostatic (Langmuir) turbulence, described by the mathematical formalism of the spin-type Hamiltonians, which was actively discussed in the recent time in the literature on statistical physics. As follows from the corresponding calculations, formation of the anticorrelated distributions of temperature and density is a universal property of the strongly-nonequilibrium plasmas governed by the spin-type Hamiltonians when they gradually approach the thermodynamic equilibrium. So, just this phenomenon could be responsibly for the anticorrelations observed in the solar wind.
Show AbstractDynamics of passive admixture in surface and subsurface external deformation field above an ocean guyot
Dynamics of passive admixture in surface and subsurface external deformation field above an ocean guyot
M. V. Shatokhin$^1$, M. A. Sokolovskiy$^{1,2}$
Within the framework of a three-layer quasi-geostrophic model, a numerical study of the effect of an isolated submarine obstacle on the movement of surface and subsurface patches of a neutral admixture transfered by a vertically homogeneous zonal current was carried out. The possibility of partial capture of impurities by quasi-stationary topographic eddy in the vicinity of the submarine obstacle is shown. The role of the initial location (both horizontally and vertically) on the resulting pollution distribution pattern is revealed.
Show AbstractPhotoelectric charging of dust inprotoplanetary disks
Photoelectric charging of dust inprotoplanetary disks
T. I. Morozova, I. A. Kuznetsov
The process of ionization-recombination of gas and charging of dust particles under the action of X-rays under space plasma conditions is considered. The conditions are found when, as a result of exposure to radiation, dust particles in a protoplanetary disk can acquire a positive charge even with low gas ionization.
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