Hierarchy of instabilities for two counterstreaming magnetized pair. Growth and saturation of the kelvinhelmholtz instability. Pomeranchuknematic instability in the presence of a weak magnetic field by daniel g. Transverse instability magnetic field thresholds of. Plasma instabilities can be divided into two general groups. Instability of twostream freeelectron laser with an. The gravitational instability of a rotating walters b. Bubbles indicative of the rti can also be seen developing into the bulk of the ejecta before breaking up and falling back. In this work we investigate the effects of an external magnetic field in the stability of the ground state of a neutral two flavor color superconductor. The impact of magnetic fields on thermal instability.
Modulational instability, quantum breathers and two. Mass and magnetic field of eruptive solar filaments ucl. Citeseerx instability of the twodimensional metallic. The kelvinhelmholtz instability of a parallel shear flow with a hyperbolictangent velocity profile has been simulated numerically at a high reynolds number.
Instability of two stream freeelectron laser with an axial guiding magnetic field article in international journal of infrared and millimeter waves 278. Magnetic fields and magnetic diagnostics for tokamak plasmas. Structural instability of two and threedimensional pyrochlore spin lattices in high magnetic fields. The stability of a plasma is an important consideration in the study of plasma physics.
The generalized buneman dispersion relation for twocomponent plasma is derived in the case of nonzero pressure of both plasma components and longitudinally dominated magnetic field. We report on magnetotransport studies of the unusual two dimensional metallic phase in high mobility simos structures. A model of twostream freeelectron lasers fel with an axial guiding magnetic field agmf is proposed and investigated in this paper. For the exact eigenstates consisting of several independent localized. The instability is intrinsically two dimensional and is.
Twostream instability as a mechanism for toroidal magnetic. Two and threedimensional instabilities of the cylinder wake. Hussein2 1department of mathematics, faculty of education, ain shams university, heliopolis, roxy, cairo, egypt. Fieldinduced magnetic instability and quantum criticality. Measuring the kelvinhelmholtz instability, stabilized by a. There is an imbalance between lefthanded and righthanded particles in a quantum system, and current flow along the magnetic field emerges at a macroscopic level. This can be readily demonstrated by moving a compass near the magnet. Magnetogravitational vortexsheet instability of two superposed conducting fluids in porous medium under strong magnetic field m. Reduction of the lateral size of inplane magnetized 2d cobalt films down to about 100 nanometers did not essentially modify their magnetic properties. Instability phase diagram in the plane magnetic fieldelectric field. A horizontal magnetic field always decreases the unstable growth rate for both fluids. Jul 19, 2006 a model of two stream freeelectron lasers fel with an axial guiding magnetic field agmf is proposed and investigated in this paper. We study a transverse instability of the nonlinear equilibria known as electron phasespace holes in the presence of a magnetic field.
The magnetic trapping argument simply states that the instability will cease when the wave magnetic field becomes so strong and traps the beam particles. Lets first consider the simple model of a plasma supported by a magnetic field b in a uniform gravitational field g. The two fluids in question may also have differing magnetic. The magnetic force is proportional to the charge q and speed v of the particle. Magnetic field induced by elliptical instability in a. The two solid boundaries are rotated at the same angular velocity in one azimuthal direction, and a rotating magnetic field is applied in the opposite azimuthal direction. It is known that the electric current along the magnetic field causes an instability, leading to a growth of the magnetic field e. Increasing magnetic fields suppress 2d instability vortex shedding, whereas 3d instabilities are influenced in a more complex way. Instability of twostream freeelectron laser with an axial. Circulating progenitor cells pcs are considered to contribute to the remodeling of atherosclerotic plaques. The magnetic rayleightaylor instability in solar prominences. Magnetic field effects on healing planet atmosphere.
The impact of normal magnetic fields on instability of. Citeseerx document details isaac councill, lee giles, pradeep teregowda. Pdf sheared magnetic field and kelvin helmholtz instability. We have also investigated the relative effect of magnetic pressure and. The nonlinear analysis of the combined effect of magnetic field and compressibility on the growth rate of rayleightaylor rt instability has been investigated for inviscid two fluid interface. In a similar manner, a bar magnet is a source of a magnetic field b g. Sections 101 considers the stability of a slip surfce between two fluids of different densities, section 106 considers the effect of a magnetic field on the problem. In a suspension of magnetic nanoplatelets in clcs, similarly as in a suspension in nematic lcs, ferromagnetic ordering of the platelets appears, which makes the suspensions sensitive also to small magnetic fields.
Brandenburg1,4 1nordita, kth royal institute of technology and stockholm university. Electron surfing acceleration by the electron twostream. Fieldinduced magnetic instability and quantum criticality in the antiferromagnet cecu 2 ge 2 skip to main content thank you for visiting. Magnetic fields and tokamak plasmas alan wootton 8 for any path l, with n the normal to a two sided surface s. To seed the instability, we add random numbers to both the x and ycomponents of the velocity with peaktopeak amplitude of 0. We have considered an interfaceparallel density dependent magnetic field and used layzers approach to analyze the problem. Suppressing the rayleighplateau instability in field. The magnetic rayleightaylor instability open access repository. Magnetization instability in a twodimensional system. Our results show that a strong magnetic field tends to increase the stability of the ground state, moving it from the unstable gapped region to the stable one.
Pdf twofluid tearing instability in forcefree magnetic. Force is zero when velocity and field are in same direction. Magneticfield induced stability in twoflavor color. We consider an initial magnetic field aligned with the shear flow, and analyse the differences between cases where the initial field is unidirectional everywhere uniform case and those where the field changes sign at the interface reversed. This demonstrates that there is a magnetic instability around h where magnetic order is absent and separates the sdw phase and the q phase. Searl effect generator electric generator magnetic field. We find that the chromomagnetic instability existing in neutral two flavor color superconductivity at moderate densities is removed by the formation of an. Magnetogravitational vortexsheet instability of two. To seed the instability, we add random numbers to both the x and ycomponents of the. Small viscosity andor slight compressibility could introduce some instability even in the presence of a strong magnetic field in a certain circumstance.
Combined effects of rotating magnetic field and rotating system on the thermocapillary instability in the floating zone crystal growth process. Electron surfing acceleration by the electron twostream instability in a weak magnetic field view the table of contents for this issue, or go to the journal homepage for more. We have observed that the magnetic field applied in the 2d plane suppresses the metallic state, causing the resistivity to increase dramatically by more than 30 times. Amplification due to twostream instability of self. In this paper, the effect of a normal magnetic field, which is perpendicular to the interface, on the instability of thermocapillary convection in a rectangular cavity with differentially heated sidewalls, filled with two viscous, immiscible, incompressible fluids, is studied under the absence of gravity. We found that the magnetic field parallel to the mainstream direction has a stabilizing effect on the shear flow. The dispersion relation and numerical calculations have been performed to obtain the dependence of the growth rate of the gravitational unstable. For b the sources are currents and changing electric fields. Gravitational instability of rotating viscoelastic. A general form for an alfvenic fluctuation is derived, with a strongly anisotropic spectrum with respect to a mean magnetic field, typical of the solar wind.
In a magnetic field, magnetic flux flows unimpeded through nonferrous workpiece material. It arises when the angular velocity of a conducting fluid in a magnetic field decreases as the distance from the rotation center increases. The kelvinhelmholtz kh instability occurring in a single shear flow configuration that is embedded in a uniform flowaligned magnetic field, is revisited by means of high resolution two. New plasma mechanism for the generation of toroidal magnetic field in the magnetosphere of crab pulsar is presented. The rayleightaylor instability rti arises whenever two fluids with different densities are arranged such that the heavier fluid sits above the lighter fluid, with a sharp interface in between. Jan, 2016 field induced magnetic instability and quantum criticality in the antiferromagnet cecu 2 ge 2 skip to main content thank you for visiting. Fieldinduced magnetic instability separates two sdws with identical symmetry as shown in fig. On the modulational instability of hydromagnetic waves parallel to the magnetic field volume 16 issue 3 einar mjolhus skip to main content accessibility help we use cookies to distinguish you from other users and to provide you with a better experience on our websites. The magnetorotational instability mri is a fluid instability that causes an accretion disk orbiting a massive central object to become turbulent. Fieldinduced magnetic instability separates two sdws with identical symmetry. This paper deals with two fundamental models for convection in a reacting fluid and porous medium with magnetic field effect. The dispersion relation is derived employing linear fluid theory. In the present work we investigate the nature of the magnetic rayleightaylor instability at a density interface permeated by an oblique, homogeneous magnetic field in an incompressible limit. The continuous dependence is unconditional in two dimensions but conditional in three dimensions.
These fields were probed using lowemittance, highly relativistic electron bunches from a laser wakefield accelerator, and a. Their surface receptor cxcr4 plays an important role in the recruitment of pcs to their target. Pomeranchuknematic instability in the presence of a weak. Two and threedimensional instabilities of the cylinder. The effects of a horizontal magnetic field on the rayleightaylor. Parametric instability of the interface between two. Gravitational instability of rotating viscoelastic partially. The suppressing effect of the magnetic field on the instability is accomplished by two parts. The parametric instability of twodimensional alfvenic turbulence has been studied via direct numerical simulations of magnetohydrodynamics. The characteristics of dispersion relation are analyzed in detail by numerical solutions, which show that the growth rate can be considerably enhanced and the operation frequency is.
The two component derivative nonlinear schrodinger equation. Like all vector fields, a magnetic field has two important mathematical properties that relates it to its sources. Dec 18, 20 this paper deals with two fundamental models for convection in a reacting fluid and porous medium with magnetic field effect. Kelvinhelmholtz and rayleightaylor instability of two. I then highlight morphology seen in the backfalling material consistent with the rayleightaylor instability rti and estimate a characteristic magnetic field strength from equations governing the instability to be 0. Two fluid tearing instability in forcefree magnetic configuration. We present experimental measurements of the femtosecond timescale generation of strong magnetic field fluctuations during the interaction of ultrashort, moderately relativistic laser pulses with solid targets. In this work we investigate the effects of an external magnetic field in the stability of the ground state of a neutral twoflavor color superconductor. Parametric instability of the interface between two viscous. This study compares the mobilization of pcs and their functional characteristics in asymptomatic subjects with stable and with unstable carotid plaques. The four magnetic regions correspond to each edge of the two magnetic poletips due to its. Observation of magnetic field generation via the weibel. The two streams are m oving in opposite directions with equal velocities parallel to the horizontal plane. Modulational instability, quantum breathers and two breathers in a frustrated ferromagnetic spin lattice under an external magnetic field.
The two primary issues involved in magnetic levitation are lifting forces. In addition we report on exact diagonalization data for finite two dimensional pyrochlore lattices up to n64 sites. Instability of the twodimensional metallic phase to parallel. Parametric instability in twodimensional alfvenic turbulence. Pdf a demonstration of extracting the strength and. The runout of the capillary while rotating at high speed under the cantilever tube support method causes instability of the magnetic abrasive behavior.
Fieldinduced magnetic instability within a superconducting. Two and threedimensional 2d and 3d instabilities in the wake of a circular cylinder placed in an electrically conducting fluid and subjected to a constant magnetic field aligned with the freestream are investigated numerically. Analysis of selfgravitational instability of viscous. In a similar model with a gravitational field, the interchange instability acts in the same way. Structural stability for two convection models in a. Pdf magnetization instability in a twodimensional system. Combined effects of rotating magnetic field and rotating.
These two properties, along with the two corresponding properties of the electric field, make up maxwells equations. Measuring the kelvinhelmholtz instability, stabilized by. The magnetic rayleightaylor instability mrti has the further complication due to the presence of a magnetic field throughout both media. The present two dimensional simulation with a high iontoelectron mass ratio shows that the modified two stream instability can be generated by the interaction of incoming and reflected ions with electromagnetic whistler mode waves propagating in the direction quasiperpendicular to the ambient magnetic field. Magnetic field induced by elliptical instability in a rotating tidallydistorted sphere view the table of contents for this issue, or go to the journal homepage for more. Magnetic fields and magnetic diagnostics for tokamak. Nordita201417 evolution of magnetic field generated by the kelvinhelmholtz instability m. We demonstrate that the solution depends continuously on changes in the chemical reaction and the electrical conductivity coefficients.
Physical effects of magnetic fields on the kelvinhelmholtz. However, in planetary magnetospheres corotational forces are dominant and change the picture slightly. Using measurements of the photospheric magnetic field, it is known that. It is also known as the velikhovchandrasekhar instability or balbushawley instability in the literature. Also for the linear instability, arising at the interface of two fluids in relative motion, the famous kelvinhelmholtz instability, a shift of the critical flow velocity towards higher values by means of a tangential magnetic field has been suggested for a long time. On the modulational instability of hydromagnetic waves. Jan 19, 2015 b, magnetic field slice transverse magnetic field component b y along the yaxis midplane, at the same time, illustrating the presence of strong filaments associated with the weibel instability. The instability of two superposed homogeneous streaming. The magnitude and direction of the magnetic force depends on the particle velocity and magnitude and direction of the magnetic field. We use different densities in the two fluids to make visualization of the interface easier.
Chromomagnetic instability and induced magnetic field in. The derived relation is also valid for other field configurations mentioned in the paper. There are two wellknown mechanisms to estimate the induced magnetic field of the weibel instability. Fieldcontrolled structures in ferromagnetic cholesteric. Combined effect of magnetic field and compressibility on. Citeseerx elliptical instability with magnetic field and. For the mhd problem, the initial magnetic field is uniform everywhere with b x 4. Fieldinduced magnetic instability and quantum criticality in. The magnetic rayleightaylor instability open access. Beta is a ratio of the plasma pressure over the magnetic field strength.
Suspensions of superparamagnetic colloids that equilibrate in a toggled magnetic field undergo a rayleighplateau instability with a characteristic wavelength. A quiescent prominence observed by hinode sot using the ca ii h. Evolution of magnetic field generated by the kelvinhelmholtz. The instability is suppressed when the chamber length l in the field direction is less than 2 the final size of the magnetic domains perpendicular to the field, d, follows a power. The linear growth and the subsequent nonlinear saturation of the instability are studied numerically. The magnetic field mainly stabilizes shortwave perturbations. This material is a liquid analog of a solid helimagnet, in which topologically stable twodimensional 2d field structures called skyrmions can be observed 28, 29. Single twodimensional 2d atomically thick magnetic particles of cobalt and iron with variable size and shape were fabricated by combining a mask technique with standard molecular beam epitaxy. Halleffect regime under the application of a parallel magnetic field. We report on magnetotransport studies of the unusual twodimensional metallic phase in high mobility simos structures. It can be useful in a variety of plasma systems, for example, in the analyses of plasma jet penetrating into background.
The fluid is perfectly conducting with low viscosity, and the strength of the applied magnetic field varies from weak to strong. The instabilities triggered when two counterstreaming pair beams collide are analyzed. Pdf magnetic rayleightaylor instability at a contact. We discuss a scenario of the field tuned changes in the groundstate properties of the frustrated spin lattices due to the coupling between spin and lattice degrees of freedom.
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