The Hall effect and Kelvin–Helmholtz instability in a plasma

1968 ◽  
Vol 46 (22) ◽  
pp. 2557-2561 ◽  
Author(s):  
Amiya K. Sen ◽  
Chih Kang Chou
Keyword(s):  
Growth Rate ◽  
Hall Effect ◽  
Upper Bound ◽  
Cyclotron Frequency ◽  
Hall Current ◽  
Unstable Mode ◽  
Helmholtz Instability ◽  
Helmholtz Problem ◽  
Ion Cyclotron ◽  
Ideal Plasma

It is shown that a new unstable mode due to the Hall effect appears in the Kelvin–Helmholtz problem in an ideal plasma. The instability appears whether or not the Kelvin–Helmholtz discontinuity is stable or unstable in the absence of a Hall current. An upper bound on the growth rate of the Hall instability is found to be of the order of the ion cyclotron frequency.

Combined Taylor and Helmholtz instability in hydromagnetics including Hall effect

1967 ◽  
Vol 1 (1) ◽  
pp. 145-155 ◽  
Author(s):  
S. P. Talwar ◽  
G. L. Kalra
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Hall Effect ◽  
Uniform Magnetic Field ◽  
Hall Current ◽  
Larmor Frequency ◽  
Larmor Radius ◽  
Helmholtz Instability ◽  
Unstable Configuration

The problem of combined Rayleigh—Taylor and Kelvin—Helmholtz instability for incompressible plasmas carrying a uniform magnetic field is investigated taking account of the Hall current. The resistivity and the finite ion Larmor radius effects are left out. It is found that the finite Larmor frequency is destabilizing in nature. The growth rate of an otherwise (without the Hall current) unstable configuration is increased, and unstable modes may be produced in otherwise stable situations for reasonably large values of the Hall current. The Hall effect also results in overstable modes.

The extension of the Miles-Howard theorem to compressible fluids

1970 ◽  
Vol 43 (4) ◽  
pp. 833-836 ◽  
Author(s):  
G. Chimonas
Keyword(s):  
Growth Rate ◽  
Shear Flow ◽  
Upper Bound ◽  
Unstable Mode ◽  
Vertical Gradient ◽  
Flow Speed ◽  
Incompressible Fluids ◽  
Compressible Fluids ◽  
Sufficient Condition ◽  
Parallel Shear Flow

A statically stable, gravitationally stratified compressible fluid containing a parallel shear flow is examined for stability against infinitesimal adiabatic perturbations. It is found that the Miles–Howard theorem of incompressible fluids may be generalized to this system, so that n2 ≥ ¼U′2 throughout the flow is a sufficient condition for stability. Here n2 is the Brunt–Väissälä frequency and U’ is the vertical gradient of the flow speed. Howard's upper bound on the growth rate of an unstable mode also generalizes to this compressible system.

scholarly journals Asymmetric Modes of the Kelvin-Helmholtz Instability in Protostellar Jets

1997 ◽  
Vol 182 ◽  
pp. 323-333
Author(s):  
James M. Stone
Keyword(s):  
Growth Rate ◽  
Unstable Mode ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Nonlinear Regime ◽  
Helmholtz Instability ◽  
Nonlinear Growth ◽  
Protostellar Jets ◽  
Sinusoidal Oscillations ◽  
Ambient Gas

The results of a detailed analysis of the linear properties, nonlinear growth, and saturation of asymmetric modes of the Kelvin-Helmholtz instability in cooling protostellar jet beams are summarized. In the linear regime, cooling can significantly alter the growth rate and wavelength of the most unstable mode in comparison to an adiabatic jet. In the nonlinear regime, sinusoidal oscillations at the maximum growth rate lead to distortions that will be observed as ‘wiggles’ or ‘kinks’ in the jet. Strong cooling behind shocks formed in the nonlinear regime can produce emission knots and filaments. In some cases, the modes grow until the jet is disrupted. Distortions in the surface of the jet drive shock spurs into the ambient gas, resulting in longitudinal acceleration. Rapid acceleration and entrainment of ambient gas is also observed if the jet is disrupted.

Excitation of ion-cyclotron waves by a spiralling ion beam in a plasma cylinder

1993 ◽  
Vol 50 (2) ◽  
pp. 331-338 ◽  
Author(s):  
S. C. Sharma ◽  
V. K. Tripathi
Keyword(s):  
Growth Rate ◽  
Energy Transfer ◽  
Beam Energy ◽  
Cyclotron Frequency ◽  
Ion Beam ◽  
Harmonic Number ◽  
Plasma Cylinder ◽  
Higher Harmonics ◽  
Ion Cyclotron Waves ◽  
Ion Cyclotron

A helical ion beam propagating through a plasma cylinder drives electrostatic ion-cyclotron waves to instability via cyclotron interaction. Higher harmonics of the beam cyclotron frequency can be generated in this way. The growth rate increases with the harmonic number. The efficiency of beam energy transfer to the wave can be of the order of a few per cent.

Gravitational instability with Hall effect in a plasma

1968 ◽  
Vol 46 (22) ◽  
pp. 2553-2556 ◽  
Author(s):  
Amiya K. Sen ◽  
Chih Kang Chou
Keyword(s):  
Growth Rate ◽  
Hall Effect ◽  
Stability Problem ◽  
Hall Current ◽  
Gravitational Instability ◽  
Jeans Criterion ◽  
Gravitational Stability

It is shown that the new modes introduced by the inclusion of the Hall effect in the gravitational stability problem of a plasma are stable. However, an old mode (which is stable in the absence of a Hall current) becomes unstable. We conclude that the Hall current has a destabilizing effect and that the Jeans criterion for stability is adversely affected by its presence. However, the growth rate of the Hall instability is found to be negligible for any astrophysical system.

scholarly journals A new upper bound for the largest growth rate of linear Rayleigh–Taylor instability

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Changsheng Dou ◽  
Jialiang Wang ◽  
Weiwei Wang
Keyword(s):  
Surface Tension ◽  
Growth Rate ◽  
Upper Bound ◽  
Viscous Fluids ◽  
Instability Condition ◽  
Interface Surface ◽  
Incompressible Viscous Fluids ◽  
Rayleigh Taylor Instability ◽  
Surface Tensor ◽  
Rt Instability

AbstractWe investigate the effect of (interface) surface tensor on the linear Rayleigh–Taylor (RT) instability in stratified incompressible viscous fluids. The existence of linear RT instability solutions with largest growth rate Λ is proved under the instability condition (i.e., the surface tension coefficient ϑ is less than a threshold $\vartheta _{\mathrm{c}}$ ϑ c ) by the modified variational method of PDEs. Moreover, we find a new upper bound for Λ. In particular, we directly observe from the upper bound that Λ decreasingly converges to zero as ϑ goes from zero to the threshold $\vartheta _{\mathrm{c}}$ ϑ c .

Fourier transform ion cyclotron resonance mass spectrometry at the true cyclotron frequency

2021 ◽  
Author(s):  
Konstantin O. Nagornov ◽  
Oleg Y. Tsybin ◽  
Edith Nicol ◽  
Anton N. Kozhinov ◽  
Yury O. Tsybin
Keyword(s):  
Mass Spectrometry ◽  
Fourier Transform ◽  
Cyclotron Resonance ◽  
Cyclotron Frequency ◽  
Ion Cyclotron Resonance ◽  
Ion Cyclotron

Magnetic fluctuations in the range of ion cyclotron frequency in ULQ and RFP plasmas

1995 ◽  
Vol 37 (12) ◽  
pp. 1433-1448 ◽  
Author(s):  
S Takeji ◽  
Y Hirano ◽  
N Inoue ◽  
J Miyazawa ◽  
J Morikawa ◽  
...  
Keyword(s):  
Cyclotron Frequency ◽  
Magnetic Fluctuations ◽  
Ion Cyclotron

scholarly journals Plasma potential enhancement by rf heating near the ion-cyclotron frequency

1986 ◽  
Vol 29 (4) ◽  
pp. 902 ◽  
Author(s):  
D. K. Smith ◽  
K. Brau ◽  
P. Goodrich ◽  
J. Irby ◽  
M. E. Mauel ◽  
...  
Keyword(s):  
Cyclotron Frequency ◽  
Plasma Potential ◽  
Rf Heating ◽  
Ion Cyclotron
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