A linear and quasi-linear investigation of the crossfield current-driven ion-acoustic instability

1982 ◽  
Vol 28 (2) ◽  
pp. 267-279 ◽  
Author(s):  
R. Bharuthram ◽  
M. A. Hellberg
Keyword(s):  
Linear Growth ◽  
Velocity Distribution Function ◽  
Linear Growth Rate ◽  
Particle Diffusion ◽  
Anomalous Resistivity ◽  
Heating Rates ◽  
Ion Heating ◽  
Acoustic Instability ◽  
Ion Acoustic ◽  
Drift Instability

The linear growth rate of the crossfield current-driven ion-acoustic instability is obtained for any equilibrium particle velocity distribution function of the type . Quasi-linear theory is then used to investigate the saturation of the instability. Several associated features, namely, particle diffusion in velocity space, anomalous resistivity, energy distribution and electron and ion heating rates are evaluated for a Maxwellian distribution. Finally, a brief comparison is made with the heating rates associated with the electron cyclotron drift instability.

scholarly journals Anomalous Transport in Current Sheets

1985 ◽  
Vol 107 ◽  
pp. 315-328
Author(s):  
J. D. Huba
Keyword(s):  
Anomalous Transport ◽  
Lower Hybrid ◽  
Diffusion Region ◽  
Transport Mechanisms ◽  
Current Sheets ◽  
Nonlinear Properties ◽  
Acoustic Instability ◽  
Ion Acoustic ◽  
Linear And Nonlinear ◽  
Drift Instability

A review of several microinstabilities that have been suggested as possible anomalous transport mechanisms in current sheets is presented. The specific application is to a ‘field reversed plasma’ which is relevant to the so-called ‘diffusion region’ of a reconnection process. The linear and nonlinear properties of the modes are discussed, and each mode is assessed as to its importance in reconnection processes based upon these properties. It is concluded that the two most relevant instabilities are the ion acoustic instability and the lower-hybrid-drift instability. However, each instability has limitations as far as reconnection is concerned, and more research is needed in this area.

Ion-Acoustic Instability and Ion Heating in an Inhomogeneous Magnetoplasma

1974 ◽  
Vol 37 (5) ◽  
pp. 1473-1473 ◽  
Author(s):  
Mitsuyasu Yatsuzuka ◽  
Kikoh Satoh ◽  
Kiyoshi Yatsui
Keyword(s):  
Ion Heating ◽  
Acoustic Instability ◽  
Ion Acoustic

Ion heating in a dusty plasma due to the dust/ion acoustic instability

1995 ◽  
Vol 22 (15) ◽  
pp. 2069-2072 ◽  
Author(s):  
D. Winske ◽  
S. Peter Gary ◽  
Michael E. Jones ◽  
M. Rosenberg ◽  
V. W. Chow ◽  
...  
Keyword(s):  
Dusty Plasma ◽  
Ion Heating ◽  
Acoustic Instability ◽  
Ion Acoustic

scholarly journals Studies of Spectral Broadening of the Lower Hybrid Wave Line in the Current-Drive Regimes and Ion Heating at the FT-2 Tokamak

2021 ◽  
Vol 47 (4) ◽  
pp. 329-336
Author(s):  
V. V. Dyachenko ◽  
A. B. Altukhov ◽  
E. Z. Gusakov ◽  
L. A. Esipov ◽  
A. N. Konovalov ◽  
...  
Keyword(s):  
Electromagnetic Waves ◽  
Low Frequency ◽  
Current Drive ◽  
Lower Hybrid ◽  
Ion Heating ◽  
Lower Hybrid Wave ◽  
Acoustic Instability ◽  
Ion Acoustic ◽  
Lower Hybrid Current Drive ◽  
High Frequency Waves

Abstract The experiments at the FT-2 tokamak are described that were focused on clearing up the role of the parametric decay instabilities in decreasing the generation efficiency of the non-inductive current excited by the electromagnetic waves in the lower hybrid frequency range. The most discussed instability of such kind is the decay of the pump wave into the daughter high-frequency waves and the low-frequency ion–acoustic quasi-modes. The studies performed have shown that, under conditions of the FT-2 experiment, the ion–acoustic instability has no decisive effect on the decrease in the efficiency of the lower hybrid current drive.

Anomalous resistivity and the nonlinear evolution of the ion-acoustic instability

2006 ◽  
Vol 111 (A1) ◽  
Author(s):  
P. Petkaki ◽  
M. P. Freeman ◽  
T. Kirk ◽  
C. E. J. Watt ◽  
R. B. Horne
Keyword(s):  
Nonlinear Evolution ◽  
Anomalous Resistivity ◽  
Acoustic Instability ◽  
Ion Acoustic

Microborings and growth in Late Ordovician halysitids and other corals

1993 ◽  
Vol 67 (6) ◽  
pp. 922-934 ◽  
Author(s):  
Robert J. Elias ◽  
Dong-Jin Lee
Keyword(s):  
Growth Rate ◽  
Linear Growth ◽  
Inverse Correlation ◽  
Weight Percent ◽  
Late Ordovician ◽  
Coral Growth ◽  
Linear Growth Rate ◽  
Skeletal Density ◽  
Rugose Coral ◽  
Endolithic Algae

Microborings in the Late Ordovician tabulate corals Catenipora rubra (a halysitid) and Manipora amicarum (a cateniform nonhalysitid) and in an epizoic solitary rugose coral differ from nearly all of those previously reported in Paleozoic corals. These microborings were formed within the coralla by endolithic algae and fungi located beneath living polyps. Comparable structures in the Late Ordovician tabulate Quepora ?agglomeratiformis (a halysitid) represent algal microborings, not spicules, and halysitids are corals, not sponges as suggested by Kaźmierczak (1989).Endolithic algae in cateniform tabulates relied primarily on light entering through the outer walls of the ranks rather than through the polyps; lacunae within coralla permitted appropriate levels of light to reach many corallites. The direction of boring was determined by corallum microstructure and possibly also by the distribution of organic matter within the skeleton. There is an apparent inverse correlation between boring activity and coral growth rate.The location and relative abundance of pyritized microborings within calcareous coralla can be established quantitatively and objectively from electron microprobe determinations of weight percent sulfur along appropriate traverses of the coral skeleton. The distribution of such microborings in Catenipora rubra and Manipora amicarum is comparable to algal banding in modern corals; this is the first report of such banding in the interiors of Paleozoic corals. Change in the intensity of boring within each corallum was evidently a response to variation in the linear growth rate of the coral, or to fluctuation in an environmental factor (perhaps light intensity) that could control both algal activity and growth rate in these corals. Change in the algal boring intensity and linear growth rate of the coral was generally but not always seasonal and usually but not invariably associated with change in the density of coral skeletal deposition.Cyclic bands of boring abundance maxima within fossil colonial corals provide a measure of annual linear growth comparable to the widely accepted method based on skeletal density bands. Algal bands are more sporadically developed than density bands within and among coralla, thus increasing the difficulty of interpretation. Fluctuations in the abundance of algal microborings apparently provide a detailed record of changes in the linear growth rate of colonies and of individuals within colonies. Combined analyses of microboring abundance and skeletal density will contribute significantly to our understanding of the biological and environmental factors involved in endolithic activity and coral growth.

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