THE ROLE OF LARGE AMPLITUDE UPSTREAM LOW-FREQUENCY WAVES IN THE GENERATION OF SUPERTHERMAL IONS AT A QUASI-PARALLEL COLLISIONLESS SHOCK:CLUSTEROBSERVATIONS

Abstract. The propagation of MHD kink/sausage low frequency waves in the magnetotail with a finite normal Bz component is addressed. The general idea is to investigate how a finite Bz may affect the propagation of MHD eigenmodes in the plasma sheet. The standard MHD equations are linearized and solved numerically in a modified Harris sheet. Boundary conditions are chosen such that energy flows outward of the frame box (free propagating system). An initial perturbation is set up in the pressure gradient term and the wave energy is then traced in the system. While a pure 1-D-Harris sheet constitutes an efficient wave guide for MHD eigenmodes, the introduction of a finite Bz in the zero-order geometry changes significantly the propagation of MHD fluctuations: the eigenmodes propagate much more slowly and carry little energy whereas a pure sound wave is excited and propagates isotropically in the system. The presence of a finite Bz thus tends to inhibit the MHD propagation of energy along the plasma sheet. It tends rather to spread the energy throughout the magnetotail. As an application of the above study, the role of a permanent X-point structure on MHD propagation in the plasma sheet is also explored.

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Large Amplitude Low Frequency Waves in a Magnetized Nonuniform Electron–Positron–Ion Plasma

Chinese Physics Letters ◽

10.1088/0256-307x/21/5/034 ◽

2004 ◽

Vol 21 (5) ◽

pp. 884-887 ◽

Cited By ~ 5

Author(s):

Q Haque ◽

H Saleem

Keyword(s):

Large Amplitude ◽

Low Frequency ◽

Ion Plasma ◽

Electron Positron ◽

Low Frequency Waves

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The interaction of high-frequency and low-frequency waves in magnetized plasmas

Journal of Plasma Physics ◽

10.1017/s0022377800026702 ◽

1988 ◽

Vol 39 (3) ◽

pp. 369-384 ◽

Cited By ~ 2

Author(s):

I. V. Relke ◽

A. M. Rubenchik

Keyword(s):

High Frequency ◽

Low Frequency ◽

Magnetized Plasmas ◽

Magnetic Field Fluctuation ◽

Hamiltonian Description ◽

Frequency Wave ◽

Magnetohydrodynamic Waves ◽

Self Focusing ◽

Low Frequency Waves

The interaction of high-frequency and low-frequency waves in magnetized plasmas is considered. The narrowness of high-frequency wave packets makes possible a concise Hamiltonian description of the problem. Some concrete problems are studied with the help of the derived equations. The competitive role of scattering in self-consistent density and magnetic-field fluctuation are considered. The self-focusing and solitons of potential plasma waves and magnetohydrodynamic waves are studied.

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A quantitative description of flagellar movement in golden hamster spermatozoa

Journal of Experimental Biology ◽

10.1242/jeb.114.1.463 ◽

1985 ◽

Vol 114 (1) ◽

pp. 463-475

Author(s):

S. Ishijima ◽

H. Mohri

Keyword(s):

Sea Urchin ◽

Golden Hamster ◽

Large Amplitude ◽

Quantitative Description ◽

Low Frequency ◽

Before And After ◽

Epididymal Spermatozoa ◽

Triton X ◽

Sea Urchin Sperm

Flagellar movement of golden hamster spermatozoa obtained from the testis and the caput and cauda epididymides was observed by a light microscope while holding them at their heads with a micropipette. Flagellar movement of capacitated spermatozoa and of reactivated spermatozoa demembranated with Triton X-100 was also observed. Testicular and caput epididymal spermatozoa showed weak movement in Tyrode's solution, whereas cauda epididymal spermatozoa showed vigorous movement. The flagellar bends of the cauda epididymal spermatozoa were almost planar. Capacitated spermatozoa moved with waves of a large amplitude. Demembranated spermatozoa reactivated with ATP only had a latent period before the initiation of flagellar movement, and beat at low frequency, whereas demembranated spermatozoa reactivated with both ATP and cAMP began to move immediately at high frequency. Thrust and hydrodynamic power output were calculated using the parameters for the typical waveforms of cauda epididymal spermatozoa before and after capacitation. The possible role of the large amplitude beat in capacitated spermatozoa is discussed. A comparison of the ‘principal’ and ‘reverse’ bends in golden hamster sperm flagella as defined by Woolley (1977) with those in sea urchin sperm flagella suggests that the so-called ‘principal’ bend in golden hamster sperm flagella corresponds to the reverse bend in sea urchin sperm flagella and vice versa.

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Regular and chaotic charged particle dynamics in low frequency waves and role of separatrix crossings

Regular and Chaotic Dynamics ◽

10.1134/s1560354710510052 ◽

2010 ◽

Author(s):

A. I. Neishtadt ◽

A. V. Artemyev ◽

L. M. Zelenyi

Keyword(s):

Charged Particle ◽

Low Frequency ◽

Particle Dynamics ◽

Low Frequency Waves

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Energy Transfer from High-Frequency to Low-Frequency Modes in Structures

Journal of Vibration and Acoustics ◽

10.1115/1.2838662 ◽

1995 ◽

Vol 117 (B) ◽

pp. 186-195 ◽

Cited By ~ 10

Author(s):

A. H. Nayfeh ◽

D. T. Mook

Keyword(s):

Energy Transfer ◽

High Frequency ◽

Large Amplitude ◽

Low Frequency ◽

Internal Resonances ◽

Parametric Resonances ◽

High Frequency Excitation ◽

Frequency Excitation ◽

Low Amplitude

A perspective of the mechanisms by which energy is transferred from high- to low-frequency modes is presented. The focus is on some recent experiments that reveal how a low-amplitude high-frequency excitation can produce a large-amplitude low-frequency response. Such a phenomenon is potentially harmful, if not catastrophic. Specifically, these experiments clarify the role of internal resonances, combination external and parametric resonances, and the interactions among modes of widely spaced frequencies.

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