Nonlinear dynamics of dust-acoustic waves in cometary plasmas: Supernonlinear periodic waves, charge asymmetry, and thermal gradients bridging astrophysical and industrial applications

The research addresses the dynamics of nonlinear magnetoacoustic waves in magnetized plasmas, crucial for understanding shock waves in plasma systems, with applications in astrophysics, fusion, and space physics. The present paper uses a multi-scale perturbation method to analyze shock wave formation in magnetized plasmas under external magnetic fields. It finds that the shock wave amplitude increases with stronger magnetic fields and perturbation intensity, while ion density and temperature only have slight effects on wave characteristics. The key breakthrough lies in simplifying plasma dynamics using the Burgers equation, offering clearer insights into plasma shock behavior. The results contribute valuable data for understanding and controlling shock waves in laboratory and space plasma environments. The findings provide insights into plasma wave control, with applications in fusion energy, astrophysical shock wave studies, and space plasma research.

Nonlinear coherent structures of electron acoustic waves in unmagnetized plasmas

This paper aims to investigate the dynamics of nonlinear waves in compressible rods made of Mooney–Rivlin materials and neo-Hookean material. Qualitative analysis of dynamics of nonlinear waves in compressible rods made of Mooney–Rivlin materials is examined using phase plane analysis in the framework of the evolution equation. The periodic and solitary wave solutions and the effects of various parameters on these wave features are also shown. Further when material constant [Formula: see text], compressible Mooney–Rivlin material transforms into a neo-Hookean material. So, the dynamics of nonlinear waves in a compressible rod made of neo-Hookean material is also studied and periodic and solitary wave features are investigated. The qualitative analysis of nonlinear solitary and periodic waves in compressible rods made of Mooney–Rivlin materials and neo-Hookean material is reported for the first time through phase plane analysis.

This study investigates the nonlinear dynamics of low-frequency dust-acoustic waves in a viscous plasma environment. It emphasizes the formation and behavior of shock and solitary waves, considering the interplay between inertial fluid dust particles and inertialess Maxwellian ions and superthermal two-electron temperature (TET). The reductive perturbation method is applied to establish the nonlinear evolution equation, which involve both the Korteveg-de-Vries-Burgers (KdVB) and modified Korteveg-de-Vries-Burgers (mKdVB) equations. The quantitative and qualitative attributes of damped oscillatory waves, monotonic shock waves, and solitary waves are examined. The mKdVB equation is shown to support the propagation of dust-acoustic solitary waves, both compressive and rarefactive in nature, while the KdVB equation admits the propagation of dust-acoustic rarefactive solitary waves and dust-acoustic shock waves. Additionally, monotonic shock wave and damped oscillatory shock wave solutions of the KdVB and mKdVB equations are also found. It is observed that as Saturn’s magnetosphere expands, both the amplitude and the width of the electric field decrease. Regarding the analysis of the TET, Our study revealed that the magnitude and width of dust-acoustic solitons, whether compressive or rarefactive, grow with an increase in cold electron temperature and the kappa electron distribution. We also demonstrated that the dust viscosity parameter and kappa distribution of electrons significantly affect the magnitude of dust-acoustic monotonic shock waves and damped oscillatory shock waves. These investigations contribute to understanding nonlinear structures in Saturn’s inner magnetosphere, a region where dust grains and superthermal TET have been detected by various satellite missions.

In a sequel to a recent work [Das, Sarma, and Talukdar, Phys. Plasmas 5, 63 (1998)], the different nonlinear plasma-acoustic waves, based on the fluid approximation, have been derived showing the coexistences of dust-acoustic waves in plasmas contaminated by dust-charged grains. The features of the nonlinear waves, depending on the plasma composition, describe various natures of solitary waves. A new formalism, known as the tanh method and stemming from the modified simple wave solution technique, has been developed for finding the soliton propagation in the nonlinear plasma wave dynamics. The method is straightforward, with minimal mathematical manipulation, finding the heuristic formation and propagation of ion-acoustic solitary waves in the dusty plasma. The main aim is, based on the tanh method, to revisit the results in a simpler case and extending them to explain the behavior of higher-order nonlinear waves derived in generalized multicomponent plasmas. The theoretical observations highlight the salient features of nonlinear waves coexisting with the dust-acoustic wave. The new findings might expect the effect, because of the dust-charged grains, to be the common feature of nonlinear waves in the dusty plasmas, and could be of interest for future experiments in laboratory as well as in space plasmas.

A theoretical investigation of one dimensional dynamics of nonlinear electrostatic dust ion acoustic waves in a magnetized dusty plasma has been made by reductive perturbation technique. The effects of both the adiabatic and the nonadiabatic dust charge variation are incorporated. The most interesting feature is that the nonlinear evolution equation of the dust ion acoustic wave for nonadiabatic dust charge variation is the Korteweg-de Vries (KdV) Burger equation, whereas for adiabatic dust charge variation, the equation is the KdV equation. A nonadiabaticity generated anomalous dissipative effect causes generation of dust ion acoustic shock waves, a new mechanism for the generation of shock waves. Numerical integration of the KdV Burger equation shows that dust ion acoustic waves admit oscillatory (dispersion dominant) or monotone (dissipation dominant) shock solutions. It is also seen that the magnetic field and the dust charge variations significantly modify the wave amplitude.

Modelling waves and their impact on moored ships

The effects of nonsteady dust charge variations and weak magnetic field on small but finite amplitude nonlinear dust acoustic wave in electronegative dusty plasma are investigated. The dynamics of the nonlinear wave are governed by a Korteweg–de Vries Burger equation that possesses dispersive shock wave. The weak magnetic field is responsible for the dispersive term, whereas nonsteady dust charge variation is responsible for dissipative term, i.e., the Burger term. The coefficient of dissipative term depends only on the obliqueness of the magnetic field. It is found that for parallel propagation the dynamics of the nonlinear wave are governed by the Burger equation that possesses monotonic shock wave. The relevances of the findings to cometary dusty plasma, e.g., Comet Halley are briefly discussed.

ABSTRACTThe interplay of dust acoustic waves (DAWs) and it's amplitude modulation is investigated in a magnetized five‐component cometary plasma comprising positively charged hydrogen and oxygen ions, negatively charged dust grains, along with superthermal electrons (solar and cometary). The interplay dynamics of the dust acoustic waves (DAWs) is described by the Kortweg–de Vries (KdV) equation. The appearance of multi‐soliton profiles are derived using Hirota's method. The amplitude modulation of the DAWs is investigated through nonlinear Schrodinger equation. In the numerical study, it appears that the dark‐envelope soliton may exist in such cometary plasmas, but the emergence of bright‐envelope soliton is not possible at any condition. Superthermality, magnetic field strength, ion and electron concentration, and other physical factors have all been explored for their impacts. The findings of this research may contribute to our understanding of the nonlinear characteristics and wave propagation stability of electrostatic wave excitations in cometary coma environments.

view Abstract Citations (2) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Heat flux instability in cometary and solar plasma Lakhina, G. S. ; Buti, B. Abstract An electromagnetic microinstability, driven by the electron heat flux in cometary and solar plasmas, is shown to get saturated due to nonlinear processes related to resonance broadening. This instability can produce a large effective collision frequency, which leads to a reduction in the heat flux. In a cometary plasma the heat flux gets reduced by a factor of 4.5, whereas in the solar plasma, at the top of the transition zone, it is reduced by a factor of 300. The instability can produce magnetic fields of the order of 0.1 γ in cometary plasma and of 10-2 gauss in solar plasma. Publication: The Astrophysical Journal Pub Date: May 1984 DOI: 10.1086/162067 Bibcode: 1984ApJ...280..917L Keywords: Collisionless Plasmas; Cometary Atmospheres; Heat Flux; Magnetohydrodynamic Stability; Plasma-Electromagnetic Interaction; Solar Atmosphere; Comet Nuclei; Electron Energy; Temperature Gradients; Astrophysics full text sources ADS |

Our aim is to develop a more general analysis of nonlinear dynamics of drift-flute waves, applicable to arbitrary plasma beta and arbitrary spatial scales in comparison with the ion Larmor radius. This study is of interest for fundamental plasma theory as well as for the interpretation of Z-pinch and laboratory astrophysics experiments. Description of low-frequency waves and in particular drift flute waves in a high beta plasma, generally speaking, requires a kinetic approach, based on the Vlasov- Maxwell set of equations. In the present work we show that the alternative two-fluid approach can adequately describe the ion perturbations with arbitrary ratio of the characteristic spatial scales to the ion Larmor radius in so-called Pade approximation. For this purpose reduced two-fluid hydrodynamic equations which describe nonlinear dynamics of the flute waves with arbitrary spatial scales and arbitrary plasma beta are derived. The linear dispersion relation of the flute waves and the Rayleigh-Taylor instability are analyzed. A general nonlinear dispersion relation which describes generation of large-scale zonal structures by the flute waves is presented and analyzed.

Based on the hydrodynamic description, the dynamics of nonlinear cylindrical waves in an isentropic plasma are investigated. The problem is considered in an electrostatic formulation for a two-dimensional plasma medium where ions form a stationary background. Proceeding from the particular, exact solution of hydrodynamic equations, we obtain the system of differential equations which describes the electron’s dynamics, taking into account the finite temperature of electrons. Moreover, we find the conditions when this system is reduced to the generalized Ermakov–Pinney equation which was used for analyzing electron dynamics. In the present calculations, a parabolic-in-radius temperature profile was used, associated with an electron density varying only with time. In the framework of the model that worked out, the influence of initial conditions and thermal effects on the regular and singular dynamics of excited waves are discussed. It is shown that the development of singular behavior due to intrinsic nonlinearity is avoided by taking into account thermal effects and the initial rotation of the electron flow.

Plasma waves are fundamental for understanding many plasma phenomena, and at high enough amplitudes, the wave can also become nonlinear and complex. Research on nonlinear dynamics of plasma waves is critical for many applications, including fusion energy, space physics and plasma engineering. Theoretical aspects of nonlinear plasma wave propagation: wave packets, solitons, modulation instability, and wave-particle interaction. We generalize the standard theories of plasma waves to include non-linear terms and discuss how these non-linear equations can be solved numerically. We further discuss the implications of these nonlinear dynamics in several plasma applications.

High-dimensional nonlinear dynamical systems, including neural networks, can be utilized as computational resources for information processing. In this sense, nonlinear wave systems are good candidates for such computational resources. Here, we propose and numerically demonstrate information processing based on nonlinear wave dynamics in microcavity lasers, i.e., optical spatiotemporal systems at microscale. A remarkable feature is its ability of high-dimensional and nonlinear mapping of input information to the wave states, enabling efficient and fast information processing at microscale. We show that the computational capability for nonlinear/memory tasks is maximized at the edge of dynamical stability. Moreover, we show that computational capability can be enhanced by applying a time-division multiplexing technique to the wave dynamics. Thus, the computational potential of the wave dynamics can sufficiently be extracted even when the number of detectors to monitor the wave states is limited. In addition, we discuss the merging of optical information processing with optical sensing, revealing a novel method for model-free sensing by using a microcavity reservoir as a sensing element. These results pave a way for on-chip photonic computing with high-dimensional dynamics and a model-free sensing method.

The nonlinear Schrödinger equation describes a wide spectrum of non-linear wave phenomena across different fields of physics and engineering, including optical pulse transmission, propagation of intense light pulses, soliton propagation, quantum optics, self-phase modulation, dynamics of ultra-cold atomic gases, non-linear dynamics of plasma waves, dynamics of wave packets, quantum information theory, etc. In this study, we investigate the higher-order non-linear Schrödinger equation (hNLSE) and the perturbed non-linear Schrödinger equation (pNLSE) with Kerr law non-linearity by using a conformable and reliable expansion scheme. The solutions are constructed in terms of transcendental functions, specifically the exponential and trigonometric functions, and their dynamics are explained through two-, three-dimensional, and contour plots using the symbolic computation software Mathematica for certain parameter values, exhibiting soliton characteristics within the defined ranges. The solutions exhibit distinct soliton characteristics, like kink-shaped, one-sided kink-shaped, anti-bell-shaped, parabolic-shaped, and others. The solutions attained are compared with those documented in the existing literature, which highlights their originality. The obtained soliton solutions hold potential for theoretical analysis of soliton propagation, non-linear dynamics of plasma waves and ultra-cold atomic gases, communications through optical fiber, etc.