On the Mechanisms of Formation of Density Cavities under Instability of Intense Langmuir Oscillations in a Plasma

The paper considers the instability of intense Langmuir oscillations in nonisothermal (Zakharov's model) and cold (Silin's model) 1D plasma. The main attention is paid to the formation of plasma density caverns in the hydrodynamic and hybrid (electrons are described hydrodynamically, ions...

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Main Author: Volodymyr Kuklin
Format: Article
Language:English
Published: V.N. Karazin Kharkiv National University Publishing 2022-09-01
Series:East European Journal of Physics
Subjects:
Online Access:https://periodicals.karazin.ua/eejp/article/view/18814
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author Volodymyr Kuklin
author_facet Volodymyr Kuklin
author_sort Volodymyr Kuklin
collection DOAJ
description The paper considers the instability of intense Langmuir oscillations in nonisothermal (Zakharov's model) and cold (Silin's model) 1D plasma. The main attention is paid to the formation of plasma density caverns in the hydrodynamic and hybrid (electrons are described hydrodynamically, ions are described by model particles) representations. In the hydrodynamic representation, with a small number of spectrum modes, large-scale plasma density caverns are observed, which rapidly deepen. This process is supported by the appearance of small-scale perturbations, and phase synchronization of the Langmuir waves of the instability spectrum is observed. This phase synchronization of the spectrum modes is quite capable of fulfilling the role that was previously proposed to be given exclusively to the effect of extrusion of particles from the cavity by the field. In hybrid models, in the region of consideration, ions are described by model particles, the number of which in the one-dimensional case 104-5*105 (which in the three-dimensional case corresponds to the number of particles 1012-1014). The initial spectrum of perturbations is very wide and rather intense, which leads to an explosive growth of perturbations in the Zakharov model and a rapid development of instability in the Silin model. In this case, in the developed instability regime, the formation of many small-scale plasma density caverns is observed. It is the presence of this small-scale modulation due to the Fermi effect that quickly forms the normal distribution of ions over velocities. In this case, the effect of particle heating due to Landau damping loses its primacy. It is shown that the caverns practically do not change their position; phase changes for the spectral components of the plasma density were not observed. Only individual small-scale caverns demonstrate dynamics similar to the development of caverns in the hydrodynamic representation.
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spelling doaj.art-ca07c0af01834a5ba1c47d30783023632023-04-26T11:52:16ZengV.N. Karazin Kharkiv National University PublishingEast European Journal of Physics2312-43342312-45392022-09-01361310.26565/2312-4334-2022-3-0118814On the Mechanisms of Formation of Density Cavities under Instability of Intense Langmuir Oscillations in a PlasmaVolodymyr Kuklin0V.N. Karazin Kharkiv National University, Kharkiv, UkraineThe paper considers the instability of intense Langmuir oscillations in nonisothermal (Zakharov's model) and cold (Silin's model) 1D plasma. The main attention is paid to the formation of plasma density caverns in the hydrodynamic and hybrid (electrons are described hydrodynamically, ions are described by model particles) representations. In the hydrodynamic representation, with a small number of spectrum modes, large-scale plasma density caverns are observed, which rapidly deepen. This process is supported by the appearance of small-scale perturbations, and phase synchronization of the Langmuir waves of the instability spectrum is observed. This phase synchronization of the spectrum modes is quite capable of fulfilling the role that was previously proposed to be given exclusively to the effect of extrusion of particles from the cavity by the field. In hybrid models, in the region of consideration, ions are described by model particles, the number of which in the one-dimensional case 104-5*105 (which in the three-dimensional case corresponds to the number of particles 1012-1014). The initial spectrum of perturbations is very wide and rather intense, which leads to an explosive growth of perturbations in the Zakharov model and a rapid development of instability in the Silin model. In this case, in the developed instability regime, the formation of many small-scale plasma density caverns is observed. It is the presence of this small-scale modulation due to the Fermi effect that quickly forms the normal distribution of ions over velocities. In this case, the effect of particle heating due to Landau damping loses its primacy. It is shown that the caverns practically do not change their position; phase changes for the spectral components of the plasma density were not observed. Only individual small-scale caverns demonstrate dynamics similar to the development of caverns in the hydrodynamic representation.https://periodicals.karazin.ua/eejp/article/view/18814intense langmuir oscillationsdescription models by zakharov and silinsmall-scale slow-moving plasma density cavernsphase synchronization
spellingShingle Volodymyr Kuklin
On the Mechanisms of Formation of Density Cavities under Instability of Intense Langmuir Oscillations in a Plasma
East European Journal of Physics
intense langmuir oscillations
description models by zakharov and silin
small-scale slow-moving plasma density caverns
phase synchronization
title On the Mechanisms of Formation of Density Cavities under Instability of Intense Langmuir Oscillations in a Plasma
title_full On the Mechanisms of Formation of Density Cavities under Instability of Intense Langmuir Oscillations in a Plasma
title_fullStr On the Mechanisms of Formation of Density Cavities under Instability of Intense Langmuir Oscillations in a Plasma
title_full_unstemmed On the Mechanisms of Formation of Density Cavities under Instability of Intense Langmuir Oscillations in a Plasma
title_short On the Mechanisms of Formation of Density Cavities under Instability of Intense Langmuir Oscillations in a Plasma
title_sort on the mechanisms of formation of density cavities under instability of intense langmuir oscillations in a plasma
topic intense langmuir oscillations
description models by zakharov and silin
small-scale slow-moving plasma density caverns
phase synchronization
url https://periodicals.karazin.ua/eejp/article/view/18814
work_keys_str_mv AT volodymyrkuklin onthemechanismsofformationofdensitycavitiesunderinstabilityofintenselangmuiroscillationsinaplasma