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22Complex Systems of Charged Particles and their Interactions with Electromagnetic Radiation 2019
SIZE DISTRIBUTION OF DUST GRAINS CREATED IN PLASMA-CHEMICAL REACTIONS INITIATED BY THE MICROWAVE RADIATION
OF A GYROTRON IN REGOLITH
V.Yu. Korolev1'2'3' N.N. Skvortsova4
1Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University,
Moscow, Russia; e-mail: bruce27@yandex.ru 2Institute of Informatics Problems, Federal Research Center "Computer Science and Control",
Russian Academy of Sciences, Moscow, Russia 3Hangzhou Dianzi University, Hangzhou, China 4Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia,
e-mail: mukudori@mail.ru
In this work, mathematical models of non(log)-Gaussian size distributions of ensembles of dust grains are considered, which are generated during the nonlinear processes of splitting and baking of dust grains [1, 2] in laboratory regolith irradiated by the microwave radiation of a powerful pulsed gyrotron. Earlier, it was shown [3] that in these experiments, explosive processes of grain dispersion and splitting by the Coulomb mechanism take place together with the baking of grains in chain exothermic plasma-chemical reactions of synthesis. As a result, a levitating cloud of charged particles appears above surface of regolith [4]. The recorded distributions of dust grains deposited on the reactor wall (see the Figure) are characterized by heavy power-law tails, which are also characteristic of lunar regolith samples. This demonstrates that it is possible to simulate the behavior of the particles of lunar regolith under earth laboratory conditions.
To the difference from the existing models, the mathematical models of grain size distribution presented in this work take into account not only the decrease in the size of the grains caused by splitting but also the increase in their size caused by the baking observed in experiments with the lunar regolith. Unlike the classical approach [4], in which the main object under study is the number of particles with a certain size, we consider the size evolution of a single grain. A natural model of the splitting/baking process is presented, which accounts for the varying intensity of the process and its dependence on parameters that characterize the evolution of the size of the grain. Our models are based on compound Cox processes [2]. Mathematical grounds for using scale-location mixtures of normal laws as models of the distribution of the logarithm of the grain size are proposed. Necessary and sufficient conditions for pure lognormal particle size distributions in nonstationary plasma-chemical processes are formulated.
The specific cases of the proposed particle size distributions models are the Reed-Jorgensen, Sorensen, and Barndorff-Nielsen distributions (see, e.g., [6]).
The work of V.Yu. Korolev was supported by the Russian Science Foundation, project No. 18-11-00155.
References
[1] A.N. Kolmogorov. 1941. (Doklady) Akad. Sci. URSS, 30. 300.
[2] V.Yu. Korolev. 2009. Informatics and Applications. 2009. 3(3). 60 (in Russian).
[3] N.N. Skvortsova et al. 2017. JETP Letters. 106 (4). 262.
[4] N.N. Skvortsova et al. 2019. JETP Letters. 109 (7) (in print).
[5] K.P. Florensky et al. Lunar Soil: Properties and Analogues. Moscow. 1975 (in Russian).
[6] V.Yu. Korolev. Probabilistic and statistical methods of volatility decomposition for chaotic processes. Moscow. 2011 (in Russian).
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