Ion flow driven by low frequency Alfvén waves in a low-beta plasma

2021 ◽  
Vol 28 (2) ◽  
pp. 022903
Author(s):  
X. Q. Lu ◽  
L. M. Yu ◽  
W. Guo ◽  
K. H. Li
Keyword(s):  
Low Frequency ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Ion Flow

Heating of ions by low-frequency Alfven waves

2007 ◽  
Vol 14 (4) ◽  
pp. 042303 ◽  
Author(s):  
Quanming Lu ◽  
Xing Li
Keyword(s):  
Low Frequency ◽  
Alfven Waves ◽  
Alfvén Waves

Nonlinear scattering of Alfvén waves off low-frequency dust modes in a magnetized dusty plasma

1998 ◽  
Vol 20 (9) ◽  
pp. 1313-1326 ◽  
Author(s):  
M. Salahuddin ◽  
A. A. Mamun ◽  
M. R. Amin ◽  
T. Ferdous ◽  
M. Salimullah
Keyword(s):  
Dusty Plasma ◽  
Low Frequency ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Nonlinear Scattering ◽  
Magnetized Dusty Plasma

Electromagnetic ion-cyclotron instability in low beta plasma with intrinsic Alfven waves

2021 ◽  
Author(s):  
GuanShan Pu ◽  
ChuanBing Wang ◽  
PeiJin Zhang ◽  
Lin Ye
Keyword(s):  
Growth Rate ◽  
Low Frequency ◽  
Alfven Waves ◽  
Qualitative Description ◽  
Alfvén Waves ◽  
Temperature Anisotropy ◽  
Dimensional Parameter ◽  
Positive Effects ◽  
Ion Cyclotron ◽  
Emic Waves

<p>Intrinsic Alfven waves (IAWs) exist pervasively in the solar-terrestrial plasma, which can preferentially heat newborn ions in the direction perpendicular to the ambient magnetic field via non-resonant interactions when the plasma beta is low. The anisotropized newborn ion populations can excite electromagnetic ion-cyclotron (EMIC) instability. Parametric calculations indicate that the lower the plasma beta is, the higher the growth rate, while the growth rate increases with the number density of newborn ions and the intensity of IAWs. The marginal stable surface in three-dimensional parameter space is also calculated, which provides a qualitative description of parametric conditions for instability. We propose that the coupled effects of non-resonant heating by IAWs and EMIC instability could be an effective mechanism for transferring the energy from low-frequency IAWs to EMIC waves with a frequency below the gyrofrequency of the corresponding ion species. Furthermore, the temperature anisotropy of background ions with the same sense has positive effects on the growth of EMIC waves excited by newborn ions.</p>

The Bell-Like Magnetosphere

1996 ◽  
Author(s):  
Charles F. Kennel
Keyword(s):  
Low Frequency ◽  
Compressional Wave ◽  
Alfven Waves ◽  
Convincing Evidence ◽  
Alfvén Waves ◽  
Wave Form ◽  
Global Mode ◽  
Critical Issues ◽  
Space Age ◽  
Field Lines

The fact that the geomagnetic field “pulsates” was known a century before the space age opened. The century of ground-based observations did lead to an effective empirical classification of the pulsations based on period, wave form, and geographical distribution (Section 3.1), but why the magnetic field of an astronomical body should oscillate on short time scales was a first-class scientific puzzle that could only by solved in the space age. Low-frequency hydromagnetic waves were first observed in the distant magnetosphere on Explorer 6 (Judge and Coleman, 1962). The task for space research was to relate the oscillations of plasma and fields in deep space to the ground observations using the refined theoretical languages of magnetohydrodynamics and plasma physics. There have been two critical issues. The first was to understand how plasma instabilities generate some of the observed pulsations. The second, the subject of this chapter, has been to understand how motions of the magnetopause induced by the variability of the solar wind are communicated to the interior of the magnetosphere. The breakthrough came when it was understood that the MHD fast mode can cross field lines and couple resonantly to localized standing Alfven waves. What is seen on the ground is due primarily to the resonant Alfven waves (Section 3.3). In Section 3.4, we provide basic theoretical information about the eigenmodes of the “MHD box” as a conceptual framework for the observations of oscillating fields and particles in the magnetospheric cavity. Space observations provided convincing evidence for the existence of standing Alfven waves shortly after the fast-wave coupling theory was proposed (Section 3.5). The next issue was which standing wave harmonics are excited (Section 3.6). Multiharmonic excitations now seem to be a semipermanent feature of the dayside magnetosphere, attesting to the constant activity at the magnetopause. There have been a few observations of the “global mode,” the low-frequency, radially standing compressional wave that may be responsible for discrete frequency resonant oscillations (Section 3.7).

scholarly journals Parametric Decay Instability and Dissipation of Low-frequency Alfvén Waves in Low-beta Turbulent Plasmas

2018 ◽  
Vol 855 (2) ◽  
pp. 139 ◽  
Author(s):  
Xiangrong Fu ◽  
Hui Li ◽  
Fan Guo ◽  
Xiaocan Li ◽  
Vadim Roytershteyn
Keyword(s):  
Low Frequency ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Decay Instability ◽  
Parametric Decay ◽  
Parametric Decay Instability ◽  
Turbulent Plasmas

Resonant four-wave mixing of finite-amplitude Alfvén waves

1996 ◽  
Vol 55 (2) ◽  
pp. 173-180 ◽  
Author(s):  
S. Rauf ◽  
J. A. Tataronis
Keyword(s):  
Evolution Equations ◽  
Low Frequency ◽  
Four Wave Mixing ◽  
Finite Amplitude ◽  
Alfven Waves ◽  
Alfven Wave ◽  
Alfvén Waves ◽  
Wave Mixing ◽  
Derivative Nonlinear Schrödinger Equation ◽  
Pump Waves

Using the derivative nonlinear SchrÖdinger equation, resonant four-wave mixing of finite-amplitude Alfvén waves is explored in this paper. The evolution equations governing the amplitudes of the interacting waves and the conservation relations ale derived from the basic equation. These evolution equations are used to study parametric amplification and oscillation of two small-amplitude Alfvén waves due to two large-amplitude pump (Alfvén) waves. It is also shown that three pump waves can mix together to generate a low-frequency Alfven wave in a dissipative plasma.

scholarly journals Effect of thermal pressure on upward plasma fluxes due to ponderomotive force of Alfvén waves

2011 ◽  
Vol 18 (2) ◽  
pp. 235-241 ◽  
Author(s):  
A. K. Nekrasov ◽  
F. Z. Feygin
Keyword(s):  
Magnetic Moment ◽  
Ponderomotive Force ◽  
Standing Waves ◽  
Low Frequency ◽  
Alfven Waves ◽  
Background Plasma ◽  
Alfvén Waves ◽  
Thermal Pressure ◽  
Plasma Displacement

Abstract. We consider the action of the ponderomotive force of low-frequency Alfvén waves on the distribution of the background plasma. It is assumed that the ponderomotive force for traveling waves arises as a result of the background inhomogeneity of medium under study. Expressions for the ponderomotive force obtained in this paper differ from previous analogous results. The induced magnetic moment of medium is taken into account. It is shown that the well-known Pitayevsky's formula for the magnetic moment is not complete. The role of the induced nonlinear thermal pressure in the evolution of the background plasma is considered. We give estimations for plasma displacement due to the long- and short-acting nonlinear wave perturbations. Some discussion of the ponderomotive action of standing waves is provided.

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