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Dust acoustic shock waves in magnetized dusty plasma

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plasma Science and Technology 2018年第7期20卷 27-34页

作者： yashika ghai nimardeep kaur kuldeep singh n s saini Department of Physics Guru Nanak Dev UniversityAmritsar-143005India

We have presented a theoretical study of the dust acoustic （DA） shock structures in a magnetized, electron depleted dusty plasma in the presence of two temperature superthermal ions. By deriving a Korteweg-de Vries-Burgers equation and studying its shock solution, we aim to highlight the effects of magnetic field and obliqueness on various properties of the DA shock structures in the presence of kappa-distributed two temperature ion population. The present model is motivated by the observations of Geotail spacecraft in the Earth＇s magnetotail and it is seen that the different physical parameters such as superthermality of the cold and hot ions, the cold to hot ion temperature ratio, the magnetic field strength, obliqueness and the dust kinematic viscosity greatly influence the dynamics of the shock structures so formed. The results suggest that the variation of superthermalities of the cold and hot ions have contrasting effects on both positive and negative polarity shock structures. Moreover, it is noted that the presence of the ambient magnetic field affects the dispersive properties of the medium and tends to make the shock structures less wide and more abrupt. The findings of present investigation may be useful in understanding the dynamics of shock waves in dusty plasma environments containing two temperature ions where the electrons are significantly depleted.

关键词： dusty plasma KdV-Burgers superthermal distribution Earth's magnetotail

FDTD Simulation on Terahertz Waves Propagation Through a dusty plasma

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plasma Science and Technology 2016年第8期18卷 798-803页

作者：王茂琰张猛李桂萍姜宝钧张小川徐军 School of Physical Electronics University of Electronic Science and Technology of ChinaChengdu 610054China The 41st Institute of China Electronics Technology Group Corporation Qingdao 266555China

The frequency dependent permittivity for dusty plasmas is provided by introducing the charging response factor and charge relaxation rate of airborne particles. The field equations that describe the characteristics of Terahertz（THz） waves propagation in a dusty plasma sheath are derived and discretized on the basis of the auxiliary differential equation（ADE） in the finite difference time domain（FDTD） method. Compared with numerical solutions in reference, the accuracy for the ADE FDTD method is validated. The reflection property of the metal Aluminum interlayer of the sheath at THz frequencies is discussed. The effects of the thickness, effective collision frequency, airborne particle density, and charge relaxation rate of airborne particles on the electromagnetic properties of Terahertz waves through a dusty plasma slab are ***, some potential applications for Terahertz waves in information and communication are analyzed.

关键词： Terahertz dusty plasma finite-difference time-domain (FDTD) blackout

Impurity-induced local modes in one-dimensional dusty plasma chains

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Chinese Physics B 2012年第11期21卷 321-326页

作者：任永超王欣上王晓钢 State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking University

The effects of impurity on eigenmodes in one-dimensional dusty plasma lattices are studied. It is found that local modes can be excited besides lattice waves, due to the existence of an impurity particle. The dispersion relations of the modes are derived accordingly. Properties of the lattice and local modes are also analyzed and discussed, particularly for their symmetric features and conditions of the mode excitation.

关键词： impurity local mode dusty plasma

Dust Acoustic Compressive Waves in a Warm dusty plasma Having Non-Thermal Ions and Non-Isothermal Electrons

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plasma Science and Technology 2015年第9期17卷 721-727页

作者： Apul N.DEV Manoj K.DEKA Rajesh SUBEDI Jnanjyoti SARMA Department of Science and Humanities College of Science and Technology Department of Applied Sciences Institute of Science and TechnologyGauhati University Department of Mathematics R.G.Baruah College

In this article an investigation is presented on the properties of dust acoustic（DA）compressive solitary wave propagation in an adiabatic dusty plasma,including the effect of nonthermal positive and negative ions and non-isothermal *** reductive perturbation method has been employed to derive the lower degree modified Kadomtsev-Petviashivili（mK-P）,3D Schamel-Korteweg-de-Vries equation or modified Kadomtsev-Petviashivili（mK-P） equations for dust acoustic solitary waves in a homogeneous,unmagnetized and collisionless plasma whose constituents are non-isothermal electrons,singly charged positive and negative non-thermal ions and massive charged dust *** stationary analytical solutions of the lower degree mK-P and mK-P equations are numerically analyzed,where the effect of various dusty plasma constituents on DA solitary wave propagation is taken into *** is observed that both the ions in dusty plasma play a key role in the formation of DA compressive solitary waves,and also the ion concentration and non-isothermal electrons control the transformation of the compressive potentials of the waves.

关键词： dusty plasma reductive perturbation method non-isothermal ions compressive solitary wave

Attenuation characteristics of obliquely incident electromagnetic wave in weakly ionized dusty plasma based on modified Bhatnagar-Gross-Krook collision model

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Chinese Physics B 2021年第4期30卷 376-382页

作者： Zhaoying Wang Lixin Guo Jiangting Li School of Physics and Optoelectronic Engineering Xidian UniversityXi'an 710071China

The attenuation characteristics of obliquely incident electromagnetic(EM) wave in L-Ka frequency band in weakly ionized dusty plasma are analyzed based on the modified Bhatnagar-Gross-Krook(BGK) collision *** to the kinetic equation and the charging theory,the total complex dielectric constant of the weakly ionized dusty plasma is derived by considering that the minimum velocity of the electron accessible to the dust particle surface is non-zero and the second potential part of the collision cross-section contributes to the *** attenuation characteristics within the modified model are compared with those within the traditional *** influence of the dusty plasma parameters and the incident angle of EM waves on the attenuation in weakly ionized dusty plasma is further ***,the influence of different reentry heights on the attenuation characteristics of the obliquely incident EM wave is *** results show that the effect of the minimum electron velocity and the second term of the collision cross-section on the attenuation characteristics of EM waves cannot be *** the dust density and dust radius are changed,the trends of the attenuation of obliquely incident EM waves are consistent,but the influence of dust density is weaker than that of dust radius due to the constraint of orbit-limited motion(OLM) *** plasma thickness,electron density,and incident angle are proportional to the attenuation amplitude of EM *** effect of different reentry heights on the attenuation obliquely incident EM waves is related to the electron density and plasma thickness.

关键词： dusty plasma electromagnetic wave absorption electromagnetic propagation plasma sheaths

Observation of Vortex Patterns in a Magnetized dusty plasma System

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plasma Science and Technology 2007年第1期9卷 11-14页

作者：黄峰叶茂福王龙刘艳红 College of Science China Agricultural UniversityBeijing 100083China Institute of PhysicsChinese Academy of SciencesBeijing 100080China Institute of Physics Chinese Academy of SciencesBeijing 100080China Department of Chemistry University of AntwerpUniversiteitsplei 1B-2610 AntwerpBelgium

Vortex patterns of dust particles have been observed in a magnetized dusty plasma system. The formation mechanism of two-dimensional （2D） vortex patterns has been investigated by analysing the forces acting on dust particles and molecular dynamics （MD） simulations in a 2D confined magnetized dusty plasma. It has been found that with a weak confining electric field and a strong magnetic field, the particles＇ trajectories will form a vortex shape. The simulation results agree with our experimental observations. In our experiments, vortex patterns can be induced via circular rotation of particles by changing the rf （radio-frequency） power in a magnetized dusty plasma.

关键词： dusty plasma vortex pattern molecular dynamic simulation

Pattern Formation in a dusty plasma System

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plasma Science and Technology 2004年第6期6卷 2571-2575页

作者：黄峰叶茂福王龙江南 Institute of Physics Chinese Academy of Sciences Beijing 100080 China

A rich variety of dust patterns have been observed in a capacitively coupled rf discharge dusty plasma system. Dust particles are synthesized through chemical reaction of the filled gas mixture during discharge. Different patterns are formed in different stages of particle growth. In the early stage of particle growth, dust cloud can be formed by a large number of small particles, and its behavior appears to be fluid-like. Such interesting nonlinear phenomena as dust void and complex dust cloud patterns are observed in this stage. As dust particles grow, the particle size and structure can be controlled to follow two different routes. In one of the routes, the particles grow up in a ball-like shape and can be formed into regular lattice and cluster patterns. In the other, the particles grow up in a fractal shape.

关键词： dusty plasma pattern formation

Machine learning combined with Langmuir probe measurements for diagnosis of dusty plasma of a positive column

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plasma Science and Technology 2021年第9期23卷 102-110页

作者： Zhe DING Jingfeng YAO Ying WANG Chengxun YUAN Zhongxiang ZHOU Anatoly A KUDRYAVTSEV Ruilin GAO Jieshu JIA School of Physics Harbin Institute of Technology.Harbin 150001People's Republic of China Heilongjiang Provincial Key Laboratory of plasma Physics and Application Technology Harbin 150001People's Republic of China Physics Department Saint Petersburg State UniversitySt.Petersburg 198504.Russia Shanghai Electro-Mechanical Engineering Institute Shanghai 201109People's Republic of China Scienee and Technology on Electromagnetic Scattering Laboratory Shanghai 200438People's Republic of China

This paper reports the use of machine learning to enhance the diagnosis of a dusty *** in a plasma has a large impact on the properties of the *** to a probe diagnostic experiment on a dust-free plasma combined with machine learning,an experiment on a dusty plasma is designed and carried *** a specific experimental device,dusty plasma with a stable and controllable dust particle density is generated.A Langmuir probe is used to measure the electron density and electron temperature under different pressures,discharge currents,and dust particle *** diagnostic result is processed through a machine learning algorithm,and the error of the predicted results under different pressures and discharge currents is analyzed,from which the law of the machine learning results changing with the pressure and discharge current is ***,the results are compared with theoretical simulations to further analyze the properties of the electron density and temperature of the dusty plasma.

关键词： dusty plasma machine learning Langmuir probe

The Excitation of the Low-Frequency Electromagnetic Wave in dusty plasma with Vortex Flows

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plasma Science and Technology 2007年第1期9卷 1-4页

作者：马骏陈银华 CAS Key Laboratory of Basic plasma Physics Department of Modern PhysicsUniversity of Science and Technology of ChinaHefei 230026China

The Excitation of Alfven wave in dusty plasma with vortex flows is investigated. The coupled equations for density and electromagnetic potential of dusty plasma with vortex-flow were obtained. The stability and amplitude behavior were studied both analytically and numerically. Using a non-modal method, it was found that the presence of dust can suppress the growth of the instability which can also be affected by the vortex eccentricity.

关键词： dusty plasma vortex-flow instability