Pub Date : 2024-09-05DOI: 10.1134/s1063780x24600841
I. M. Kutsyk, E. I. Bochkov
Abstract
The initiation of a positive corona discharge near a model hydrometeor in air is studied numerically. Hydrometeors in the form of an ellipsoid of revolution and a cylinder with two hemispheres at the ends are considered as models. Threshold characteristics (external electric field strength, particle charge) are obtained for hydrometers of various sizes and shapes at an atmospheric pressure of 0.4−1 atm. Analysis of the results of numerous calculation options shows that the threshold field strength at the top of the hydrometeor is determined by the curvature radius of the surface at this point and air pressure. A universal dependence of the reduced threshold field strength on the product of the curvature radius of the surface and air pressure is obtained. The simulation results indicate the possibility of initiating a corona discharge in a thundercloud from the top of a hydrometeor less than a centimeter long at a subthreshold reduced field strength of 10−15 kV∕(cm atm).
{"title":"Initiation of a Corona Discharge from Model Hydrometeors in an External Electric Field","authors":"I. M. Kutsyk, E. I. Bochkov","doi":"10.1134/s1063780x24600841","DOIUrl":"https://doi.org/10.1134/s1063780x24600841","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The initiation of a positive corona discharge near a model hydrometeor in air is studied numerically. Hydrometeors in the form of an ellipsoid of revolution and a cylinder with two hemispheres at the ends are considered as models. Threshold characteristics (external electric field strength, particle charge) are obtained for hydrometers of various sizes and shapes at an atmospheric pressure of 0.4−1 atm. Analysis of the results of numerous calculation options shows that the threshold field strength at the top of the hydrometeor is determined by the curvature radius of the surface at this point and air pressure. A universal dependence of the reduced threshold field strength on the product of the curvature radius of the surface and air pressure is obtained. The simulation results indicate the possibility of initiating a corona discharge in a thundercloud from the top of a hydrometeor less than a centimeter long at a subthreshold reduced field strength of 10−15 kV∕(cm atm).</p>","PeriodicalId":735,"journal":{"name":"Plasma Physics Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1134/s1063780x24600713
I. M. Balachenkov, Yu. V. Petrov, V. K. Gusev, N. N. Bakharev, N. S. Zhiltsov, G. S. Kurskiev, V. B. Minaev, I. V. Miroshnikov, A. M. Ponomarenko, N. V. Sakharov, A. Yu. Telnova, E. E. Tkachenko, P. B. Shchegolev, A. Yu. Yashin
Abstract
In experiments with neutral beam injection on the Globus-M2 spherical tokamak, sequences of long-lasting harmonics of toroidal Alfvén modes were discovered, equidistant from each other in frequency and shifted from zero by a constant value. Using microwave Doppler backscattering diagnostics, the central localization of toroidal modes was determined. In this work, the possibility of “splitting” of toroidal harmonics due to the Doppler shift caused by the toroidal rotation of the plasma is being discussed. It is found that the unshifted frequency of the toroidal Alfvén mode obtained from the spectrum of the magnetic probe signal is in good agreement with the frequency of the mode calculated at the mode location radius, and the toroidal rotation frequency, also determined from the spectrum of the magnetic probe signal, correlates well with the rotation frequency measured using charge exchange spectroscopy diagnostics, but differs by a constant amount. Possible reasons for the discrepancies are being discussed.
{"title":"Effect of Plasma Toroidal Rotation on Toroidal Alfvén Eigenmode Spectrum in Globus-M2 Spherical Tokamak","authors":"I. M. Balachenkov, Yu. V. Petrov, V. K. Gusev, N. N. Bakharev, N. S. Zhiltsov, G. S. Kurskiev, V. B. Minaev, I. V. Miroshnikov, A. M. Ponomarenko, N. V. Sakharov, A. Yu. Telnova, E. E. Tkachenko, P. B. Shchegolev, A. Yu. Yashin","doi":"10.1134/s1063780x24600713","DOIUrl":"https://doi.org/10.1134/s1063780x24600713","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>In experiments with neutral beam injection on the Globus-M2 spherical tokamak, sequences of long-lasting harmonics of toroidal Alfvén modes were discovered, equidistant from each other in frequency and shifted from zero by a constant value. Using microwave Doppler backscattering diagnostics, the central localization of toroidal modes was determined. In this work, the possibility of “splitting” of toroidal harmonics due to the Doppler shift caused by the toroidal rotation of the plasma is being discussed. It is found that the unshifted frequency of the toroidal Alfvén mode obtained from the spectrum of the magnetic probe signal is in good agreement with the frequency of the mode calculated at the mode location radius, and the toroidal rotation frequency, also determined from the spectrum of the magnetic probe signal, correlates well with the rotation frequency measured using charge exchange spectroscopy diagnostics, but differs by a constant amount. Possible reasons for the discrepancies are being discussed.</p>","PeriodicalId":735,"journal":{"name":"Plasma Physics Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1134/s1063780x24600877
D. A. Shutov, A. N. Ivanov, P. A. Ignat’eva, V. V. Rybkin
Abstract
We propose a 0-D model describing processes in a system comprising an atmospheric pressure DC discharge and aqueous nickel nitrate solution. The model is represented as two coupled subsystems: plasma and solution. Characteristics of the discharge plasma have been determined by jointly solving the Boltzmann equation for electrons; equations of vibrational kinetics for the ground states of N2, O2, NO, H2, and H2O molecules; and equations of chemical kinetics (328 reactions, 34 components). In doing so, use was made of experimentally determined reduced electric field strength and vibrational and gas temperatures. The kinetics of the processes in the solution included 121 reactions and 34 components. The calculation results agree with experimental data on the vibrational temperatures of N2(X) molecules, the kinetics of the decrease in Ni2+ concentration, and the variation in solution pH. We have determined the degree of Ni2+ conversion and the energy yield of conversion and identified the mechanisms that determine the concentration of the major solution components.
{"title":"Simulation of Processes Initiated in Nickel Nitrate Aqueous Solution by an Atmospheric Pressure DC Gas Discharge","authors":"D. A. Shutov, A. N. Ivanov, P. A. Ignat’eva, V. V. Rybkin","doi":"10.1134/s1063780x24600877","DOIUrl":"https://doi.org/10.1134/s1063780x24600877","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>We propose a 0-D model describing processes in a system comprising an atmospheric pressure DC discharge and aqueous nickel nitrate solution. The model is represented as two coupled subsystems: plasma and solution. Characteristics of the discharge plasma have been determined by jointly solving the Boltzmann equation for electrons; equations of vibrational kinetics for the ground states of N<sub>2</sub>, O<sub>2</sub>, NO, H<sub>2</sub>, and H<sub>2</sub>O molecules; and equations of chemical kinetics (328 reactions, 34 components). In doing so, use was made of experimentally determined reduced electric field strength and vibrational and gas temperatures. The kinetics of the processes in the solution included 121 reactions and 34 components. The calculation results agree with experimental data on the vibrational temperatures of N<sub>2</sub>(X) molecules, the kinetics of the decrease in Ni<sup>2+</sup> concentration, and the variation in solution pH. We have determined the degree of Ni<sup>2+</sup> conversion and the energy yield of conversion and identified the mechanisms that determine the concentration of the major solution components.</p>","PeriodicalId":735,"journal":{"name":"Plasma Physics Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1134/s1063780x24600804
E. N. Sidorov, V. I. Batkin, I. A. Ivanov, K. N. Kuklin, N. A. Melnikov, S. V. Polosatkin, V. V. Postupaev, A. F. Rovenskikh
Abstract
The results of preliminary experiments on measuring the spatial asymmetry of plasma flows in the GOL-NB device using movable Mach probe are presented and the diagnostics used is described. In the experiments, the high-field sections were mounted in the configuration with solenoidal magnetic field. The dynamics of plasma flows was recorded which was expected in the trap: the plasma flowed from the plasma gun along the magnetic field, accumulated in the GOL-NB central trap, and then after the plasma gun was switched off, flowed out from the central trap in two directions. At time of transition from the stage of plasma accumulation to the stage of its decay, the direction of plasma flow in the input high-field section was inverted. The balance of particles in the central trap is discussed. Experiments have shown that this technique can be used for studying the effects of improving plasma confinement after switching to the multiple-mirror configuration of high-field sections, in which, according to theory, under optimal conditions, a flow of b-ackscattered particles should arise, which will return them from the multiple-mirror sections to the confinement zone.
摘要 介绍了使用可移动马赫探针测量 GOL-NB 设备中等离子流空间不对称的初步实验结果，并描述了所使用的诊断方法。在实验中，高场部分被安装在具有螺线管磁场的配置中。实验记录了等离子体在阱中的流动动态：等离子体从等离子体枪中沿着磁场流动，在 GOL-NB 中央阱中积聚，等离子体枪关闭后，等离子体从中央阱向两个方向流动。从等离子体积聚阶段过渡到等离子体衰减阶段时，等离子体在输入高场部分的流动方向发生了逆转。讨论了中央阱中粒子的平衡问题。实验表明，这种技术可用于研究改用多镜配置高场部分后改善等离子体束缚的效果，根据理论，在最佳条件下，应该会出现 b 反向散射粒子流，它们将从多镜部分返回束缚区。
{"title":"Studies of Plasma Flow Spatial Asymmetry Using Mach Probe in GOL-NB Device","authors":"E. N. Sidorov, V. I. Batkin, I. A. Ivanov, K. N. Kuklin, N. A. Melnikov, S. V. Polosatkin, V. V. Postupaev, A. F. Rovenskikh","doi":"10.1134/s1063780x24600804","DOIUrl":"https://doi.org/10.1134/s1063780x24600804","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of preliminary experiments on measuring the spatial asymmetry of plasma flows in the GOL-NB device using movable Mach probe are presented and the diagnostics used is described. In the experiments, the high-field sections were mounted in the configuration with solenoidal magnetic field. The dynamics of plasma flows was recorded which was expected in the trap: the plasma flowed from the plasma gun along the magnetic field, accumulated in the GOL-NB central trap, and then after the plasma gun was switched off, flowed out from the central trap in two directions. At time of transition from the stage of plasma accumulation to the stage of its decay, the direction of plasma flow in the input high-field section was inverted. The balance of particles in the central trap is discussed. Experiments have shown that this technique can be used for studying the effects of improving plasma confinement after switching to the multiple-mirror configuration of high-field sections, in which, according to theory, under optimal conditions, a flow of b-ackscattered particles should arise, which will return them from the multiple-mirror sections to the confinement zone.</p>","PeriodicalId":735,"journal":{"name":"Plasma Physics Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1134/s1063780x24600889
S. A. Pikuz, I. N. Tilikin, V. M. Romanova, A. R. Mingaleev, T. A. Shelkovenko
Abstract
The results of studying instabilities in flat aluminum 4-μm-thick foils exploded using the GVP generator with a short circuit current of 10 kA and a current rise time of 350 ns are presented. The dynamics of foil destruction during the explosion was studied using laser probing. During the experiments, it was ascertained that in the presence of the two-dimensional structure of foil, the growth rates of instabilities and their nature depend on the foil orientation relative to the direction of current flow. The conditions are cleared up, under which during the explosion of foils with two-dimensional inherent structures, the development of instabilities is slowed down.
{"title":"Development of Instabilities in Thin Aluminum Foils Exploded Using Generator with Current of up to 10 kA","authors":"S. A. Pikuz, I. N. Tilikin, V. M. Romanova, A. R. Mingaleev, T. A. Shelkovenko","doi":"10.1134/s1063780x24600889","DOIUrl":"https://doi.org/10.1134/s1063780x24600889","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of studying instabilities in flat aluminum 4-μm-thick foils exploded using the GVP generator with a short circuit current of 10 kA and a current rise time of 350 ns are presented. The dynamics of foil destruction during the explosion was studied using laser probing. During the experiments, it was ascertained that in the presence of the two-dimensional structure of foil, the growth rates of instabilities and their nature depend on the foil orientation relative to the direction of current flow. The conditions are cleared up, under which during the explosion of foils with two-dimensional inherent structures, the development of instabilities is slowed down.</p>","PeriodicalId":735,"journal":{"name":"Plasma Physics Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.1134/s1063780x24600683
K. N. Mitrofanov, A. N. Gritsuk, V. V. Aleksandrov, A. V. Branitsky, E. V. Grabovski, I. N. Frolov, V. V. Ryzhakov
Abstract
The results of research on the creation of a powerful source of soft X-ray radiation (SXR, hν > 100 eV) based on the Z-pinch of compact nested arrays are presented. One of the applications of such an SXR source can be radiation ablation of targets made of various substances in experiments on high-energy density physics and extreme states of matter, which are currently being actively carried out worldwide. Experiments are carried out on plasma implosion of combined nested arrays with different ratios of array radii at a discharge current level of up to 3.5 MA at the pulse power facility Angara-5-1. The outer array consisted of fibers of a substance with a low atomic number (polypropylene) and the inner array consisted of a substance with a high atomic number (tungsten). It is shown that in the case of nested arrays of this design, it is possible to obtain a significant (~1.4 times) increase in the peak SXR power compared to single W arrays with the same parameters as the W array in the inner array. At the same time, spectral data obtained using a “flat field” grazing incidence spectrograph demonstrate a significant decrease in the fraction of tungsten ions in the trailing plasma around the pinch of nested arrays. By optimizing the linear mass of the outer array and its radius, powerful and short SXR pulses with amplitude of ~10 TW, energy of ~130 kJ and duration of ~4–5 ns are obtained. This made it possible to increase the incident power density and fluence on the target up to 1.55 TW/cm2 and 17 kJ/cm2, respectively, in experiments on extreme states of matter currently being carried out at the facility.
摘要 介绍了在紧凑嵌套阵列的 Z-pinch 基础上创建强大的软 X 射线辐射源（SXR，hν > 100 eV）的研究成果。这种软 X 射线辐射源的应用之一，是在高能量密度物理和极端物质状态实验中对各种物质制成的目标进行辐射烧蚀，这些实验目前正在全球范围内积极开展。在安加拉-5-1 脉冲功率设备上，对具有不同阵列半径比的组合嵌套阵列进行了等离子内爆实验，放电电流最高达 3.5 兆帕。外层阵列由低原子序数物质（聚丙烯）纤维组成，内层阵列由高原子序数物质（钨）组成。结果表明，在这种设计的嵌套阵列中，与内阵列中具有与 W 阵列相同参数的单 W 阵列相比，SXR 功率峰值有可能显著增加（约 1.4 倍）。同时，使用 "平场 "掠入射光谱仪获得的光谱数据表明，嵌套阵列夹角周围拖曳等离子体中的钨离子比例显著下降。通过优化外层阵列的线性质量及其半径，可以获得振幅约为 10 TW、能量约为 130 kJ、持续时间约为 4-5 ns 的强力短 SXR 脉冲。这使得在该设施目前正在进行的极端物质状态实验中，将目标上的入射功率密度和通量分别提高到 1.55 TW/cm2 和 17 kJ/cm2。
{"title":"Powerful Source of Soft X-Ray Radiation Based on Z-Pinch of Nested Arrays for Experiments in High-Energy Density Physics","authors":"K. N. Mitrofanov, A. N. Gritsuk, V. V. Aleksandrov, A. V. Branitsky, E. V. Grabovski, I. N. Frolov, V. V. Ryzhakov","doi":"10.1134/s1063780x24600683","DOIUrl":"https://doi.org/10.1134/s1063780x24600683","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of research on the creation of a powerful source of soft X-ray radiation (SXR, <i>h</i>ν > 100 eV) based on the Z-pinch of compact nested arrays are presented. One of the applications of such an SXR source can be radiation ablation of targets made of various substances in experiments on high-energy density physics and extreme states of matter, which are currently being actively carried out worldwide. Experiments are carried out on plasma implosion of combined nested arrays with different ratios of array radii at a discharge current level of up to 3.5 MA at the pulse power facility Angara-5-1. The outer array consisted of fibers of a substance with a low atomic number (polypropylene) and the inner array consisted of a substance with a high atomic number (tungsten). It is shown that in the case of nested arrays of this design, it is possible to obtain a significant (~1.4 times) increase in the peak SXR power compared to single W arrays with the same parameters as the W array in the inner array. At the same time, spectral data obtained using a “flat field” grazing incidence spectrograph demonstrate a significant decrease in the fraction of tungsten ions in the trailing plasma around the pinch of nested arrays. By optimizing the linear mass of the outer array and its radius, powerful and short SXR pulses with amplitude of ~10 TW, energy of ~130 kJ and duration of ~4–5 ns are obtained. This made it possible to increase the incident power density and fluence on the target up to 1.55 TW/cm<sup>2</sup> and 17 kJ/cm<sup>2</sup>, respectively, in experiments on extreme states of matter currently being carried out at the facility.</p>","PeriodicalId":735,"journal":{"name":"Plasma Physics Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.1134/s1063780x24600737
A. V. Ponomarev, D. K. Ul’yanov
Abstract
The method for determining the absolute plasma density in sources that create plasma in the strong magnetic field using the electron beam has been developed and tested. The results of plasma density measurements in the source of tubular plasma used in research on plasma relativistic microwave electronics are presented. It was shown that at time of switching-on plasma maser, for discharge currents of 5, 9, and 20 A, the plasma densities were (3 ± 0.3) × 1012, (5.5 ± 0.6) × 1012, and (9.5 ± 1) × 1012 cm–3, respectively. Comparison with the probe measurements previously performed, as well as with the numerical calculations made using the KARAT code, showed good agreement between the results of microwave measurements and numerical calculations, while the measurement error did not exceed 15%. The results of probe measurements much stronger deviate from the results of microwave measurements, which is associated with the presence of the strong magnetic field in the plasma source.
{"title":"Microwave Method of Tubular Plasma Density Measurement for Relativistic Microwave Oscillator","authors":"A. V. Ponomarev, D. K. Ul’yanov","doi":"10.1134/s1063780x24600737","DOIUrl":"https://doi.org/10.1134/s1063780x24600737","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The method for determining the absolute plasma density in sources that create plasma in the strong magnetic field using the electron beam has been developed and tested. The results of plasma density measurements in the source of tubular plasma used in research on plasma relativistic microwave electronics are presented. It was shown that at time of switching-on plasma maser, for discharge currents of 5, 9, and 20 A, the plasma densities were (3 ± 0.3) × 10<sup>12</sup>, (5.5 ± 0.6) × 10<sup>12</sup>, and (9.5 ± 1) × 10<sup>12</sup> cm<sup>–3</sup>, respectively. Comparison with the probe measurements previously performed, as well as with the numerical calculations made using the KARAT code, showed good agreement between the results of microwave measurements and numerical calculations, while the measurement error did not exceed 15%. The results of probe measurements much stronger deviate from the results of microwave measurements, which is associated with the presence of the strong magnetic field in the plasma source.</p>","PeriodicalId":735,"journal":{"name":"Plasma Physics Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.1134/s1063780x23600809
S. Bansal, T. S. Gill
Abstract
The propagation of electron-acoustic waves in a collisionless unmagnetized plasma composed of hot electrons obeying the Cairns–Gurevich (CG) distribution, inertial cold electrons and stationary ions are considered. The basic field equations of the above described plasma is re-examined through the use of the modified Poincare–Lighthill–Kuo (PLK) method. Introducing the strained coordinates and expanding the field quantities into the parameter (epsilon ), a set of differential equations is obtained. The lowest order term in the perturbation expansion is governed by the modified KdV equation, whereas the second order term is governed by the modified linearized KdV equation with nonhomogeneous term. Then, studying the localized travelling wave solution for the evolution equations, the strained coordinates for this order is determined so as to remove the possible secularities that might occur in the solution. It is observed that the ratio of the second order term to the first order term in the perturbation expansion is negative and not so small. This is equivalent to saying that the contribution of second order term decreases the wave amplitude. In other words, retaining only the first order term in the perturbation expansion overestimates the real value of the field quantities.
{"title":"Higher Order Corrections on the Plasma Wave Characteristics with Cairns–Gurevich Distribution","authors":"S. Bansal, T. S. Gill","doi":"10.1134/s1063780x23600809","DOIUrl":"https://doi.org/10.1134/s1063780x23600809","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The propagation of electron-acoustic waves in a collisionless unmagnetized plasma composed of hot electrons obeying the Cairns–Gurevich (CG) distribution, inertial cold electrons and stationary ions are considered. The basic field equations of the above described plasma is re-examined through the use of the modified Poincare–Lighthill–Kuo (PLK) method. Introducing the strained coordinates and expanding the field quantities into the parameter <span>(epsilon )</span>, a set of differential equations is obtained. The lowest order term in the perturbation expansion is governed by the modified KdV equation, whereas the second order term is governed by the modified linearized KdV equation with nonhomogeneous term. Then, studying the localized travelling wave solution for the evolution equations, the strained coordinates for this order is determined so as to remove the possible secularities that might occur in the solution. It is observed that the ratio of the second order term to the first order term in the perturbation expansion is negative and not so small. This is equivalent to saying that the contribution of second order term decreases the wave amplitude. In other words, retaining only the first order term in the perturbation expansion overestimates the real value of the field quantities.</p>","PeriodicalId":735,"journal":{"name":"Plasma Physics Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.1134/s1063780x23601232
R. B. Kian, M. H. Mahdieh
Abstract
The nonlinear propagation of small amplitude dust acoustic solitary waves (DASWs) in a magnetized dusty plasma, containing Boltzmann distributed electrons of two distinct temperatures (low and high electron temperatures), negatively charged dust particles, and ions with two distinct temperatures (low and high ion temperatures) following Boltzmann distribution, is studied by deriving the Korteweg–de Vries (K–dV) equation. It is found that the characteristics of DASWs are significantly modified by two different temperature electrons (as well as ions), the external magnetic field, obliqueness of the system, and the number densities of two types of ions. It is shown that both compressive and rarefactive dust acoustic solitons occur in this case.
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Pub Date : 2024-07-30DOI: 10.1134/s1063780x24600865
M. A. Yudenkova, D. A. Klimachkov, A. S. Petrosyan
Abstract
A theory of large-scale flows in a rotating astrophysical plasma under conditions of non-trivial properties of the physical medium, which are not described by the classical hydrodynamic theory of plasma, is developed. As a first step, the theory is developed within a neutral fluid model to describe astrophysical plasma, with a subsequent generalization in mind to take into account magnetic effects. Such a model is of independent importance for studying turbulent dynamo in star-forming regions in galaxies and hydrodynamic instabilities in poorly ionized disks, for describing meridional flows below convective zones in low-mass stars and on the Sun, as well as for studying oscillations of the Sun and stars. Therefore, the results obtained have a wider application, e.g., for describing geophysical currents. The theory is based on two key ideas developed in plasma astrophysics: the use of a shallow water model with large-scale compressibility and the use of a two-layer shallow water model. Equations for two-layer shallow water are derived taking into account rotation and the effect of flow sphericity on rotation, in which the effects of large-scale compressibility are taken into account in the upper layer. For a rotating system, dispersion relations are obtained for Poincaré waves in two-layer shallow water, taking into account large-scale compressibility; similar dispersion relations for Poincaré waves are obtained in the high-frequency limit taking into account the effect of sphericity on rotation; in the low-frequency limit, a dispersion relation is obtained for Rossby waves. It is shown that the dispersion relations for Poincaré waves, taking into account the sphericity of the flow, have a qualitatively different form, which leads to three-wave interactions of Poincaré waves and the interaction of two Poincaré waves with a Rossby wave, which are not observed in a single-layer flow of a compressible fluid. All types of three-wave interactions for the flows under consideration are studied using the method of multiscale expansions.
{"title":"Large-Scale Hydrodynamic Flows in Media with Variable Thermodynamic Characteristics","authors":"M. A. Yudenkova, D. A. Klimachkov, A. S. Petrosyan","doi":"10.1134/s1063780x24600865","DOIUrl":"https://doi.org/10.1134/s1063780x24600865","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A theory of large-scale flows in a rotating astrophysical plasma under conditions of non-trivial properties of the physical medium, which are not described by the classical hydrodynamic theory of plasma, is developed. As a first step, the theory is developed within a neutral fluid model to describe astrophysical plasma, with a subsequent generalization in mind to take into account magnetic effects. Such a model is of independent importance for studying turbulent dynamo in star-forming regions in galaxies and hydrodynamic instabilities in poorly ionized disks, for describing meridional flows below convective zones in low-mass stars and on the Sun, as well as for studying oscillations of the Sun and stars. Therefore, the results obtained have a wider application, e.g., for describing geophysical currents. The theory is based on two key ideas developed in plasma astrophysics: the use of a shallow water model with large-scale compressibility and the use of a two-layer shallow water model. Equations for two-layer shallow water are derived taking into account rotation and the effect of flow sphericity on rotation, in which the effects of large-scale compressibility are taken into account in the upper layer. For a rotating system, dispersion relations are obtained for Poincaré waves in two-layer shallow water, taking into account large-scale compressibility; similar dispersion relations for Poincaré waves are obtained in the high-frequency limit taking into account the effect of sphericity on rotation; in the low-frequency limit, a dispersion relation is obtained for Rossby waves. It is shown that the dispersion relations for Poincaré waves, taking into account the sphericity of the flow, have a qualitatively different form, which leads to three-wave interactions of Poincaré waves and the interaction of two Poincaré waves with a Rossby wave, which are not observed in a single-layer flow of a compressible fluid. All types of three-wave interactions for the flows under consideration are studied using the method of multiscale expansions.</p>","PeriodicalId":735,"journal":{"name":"Plasma Physics Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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