A toroidal mode driven by ion temperature gradients and magnetic-field curvature

1986 ◽  
Vol 8 (5) ◽  
pp. 507-522 ◽  
Author(s):  
P. Olla
Keyword(s):  
Magnetic Field ◽  
Temperature Gradients ◽  
Ion Temperature ◽  
Toroidal Mode ◽  
Field Curvature

Effects of ion temperature gradients on the formation of drift-Alfvén vortex structures in dusty plasmas

2002 ◽  
Vol 9 (5) ◽  
pp. 1539-1543 ◽  
Author(s):  
O. G. Onishchenko ◽  
O. A. Pokhotelov ◽  
R. Z. Sagdeev ◽  
V. P. Pavlenko ◽  
L. Stenflo ◽  
...  
Keyword(s):  
Dusty Plasmas ◽  
Vortex Structures ◽  
Temperature Gradients ◽  
Ion Temperature

scholarly journals Multifrequency compressional magnetic field oscillations and their relation to multiharmonic toroidal mode standing Alfvén waves

2015 ◽  
Vol 120 (12) ◽  
pp. 10,384-10,403 ◽  
Author(s):  
Kazue Takahashi ◽  
Colin Waters ◽  
Karl-Heinz Glassmeier ◽  
Craig A. Kletzing ◽  
William S. Kurth ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Toroidal Mode

scholarly journals Dependence on ion temperature of shallow-angle magnetic presheaths with adiabatic electrons

2019 ◽  
Vol 85 (6) ◽  
Author(s):  
Alessandro Geraldini ◽  
F. I. Parra ◽  
F. Militello
Keyword(s):  
Magnetic Field ◽  
Fluid Model ◽  
Boltzmann Distribution ◽  
Distribution Functions ◽  
Magnetized Plasma ◽  
Electron Mass ◽  
Ion Temperature ◽  
Ion Distribution ◽  
Ionic Charge ◽  
The Magnetic Field

The magnetic presheath is a boundary layer occurring when magnetized plasma is in contact with a wall and the angle $\unicode[STIX]{x1D6FC}$ between the wall and the magnetic field $\boldsymbol{B}$ is oblique. Here, we consider the fusion-relevant case of a shallow-angle, $\unicode[STIX]{x1D6FC}\ll 1$ , electron-repelling sheath, with the electron density given by a Boltzmann distribution, valid for $\unicode[STIX]{x1D6FC}/\sqrt{\unicode[STIX]{x1D70F}+1}\gg \sqrt{m_{\text{e}}/m_{\text{i}}}$ , where $m_{\text{e}}$ is the electron mass, $m_{\text{i}}$ is the ion mass, $\unicode[STIX]{x1D70F}=T_{\text{i}}/ZT_{\text{e}}$ , $T_{\text{e}}$ is the electron temperature, $T_{\text{i}}$ is the ion temperature and $Z$ is the ionic charge state. The thickness of the magnetic presheath is of the order of a few ion sound Larmor radii $\unicode[STIX]{x1D70C}_{\text{s}}=\sqrt{m_{\text{i}}(ZT_{\text{e}}+T_{\text{i}})}/ZeB$ , where e is the proton charge and $B=|\boldsymbol{B}|$ is the magnitude of the magnetic field. We study the dependence on $\unicode[STIX]{x1D70F}$ of the electrostatic potential and ion distribution function in the magnetic presheath by using a set of prescribed ion distribution functions at the magnetic presheath entrance, parameterized by $\unicode[STIX]{x1D70F}$ . The kinetic model is shown to be asymptotically equivalent to Chodura’s fluid model at small ion temperature, $\unicode[STIX]{x1D70F}\ll 1$ , for $|\text{ln}\,\unicode[STIX]{x1D6FC}|>3|\text{ln}\,\unicode[STIX]{x1D70F}|\gg 1$ . In this limit, despite the fact that fluid equations give a reasonable approximation to the potential, ion gyro-orbits acquire a spatial extent that occupies a large portion of the magnetic presheath. At large ion temperature, $\unicode[STIX]{x1D70F}\gg 1$ , relevant because $T_{\text{i}}$ is measured to be a few times larger than $T_{\text{e}}$ near divertor targets of fusion devices, ions reach the Debye sheath entrance (and subsequently the wall) at a shallow angle whose size is given by $\sqrt{\unicode[STIX]{x1D6FC}}$ or $1/\sqrt{\unicode[STIX]{x1D70F}}$ , depending on which is largest.

Effect of the magnetic field curvature on the generation of zonal flows by drift-Alfvén waves

2007 ◽  
Vol 33 (5) ◽  
pp. 407-419 ◽  
Author(s):  
A. B. Mikhailovskii ◽  
E. A. Kovalishen ◽  
M. S. Shirokov ◽  
V. S. Tsypin ◽  
R. M. O. Galvão
Keyword(s):  
Magnetic Field ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Zonal Flows ◽  
Field Curvature ◽  
The Magnetic Field

Simulation of a magnetic field and ion temperature measurement in a Tokamak by Thomson scattering

1982 ◽  
Vol 24 (11) ◽  
pp. 1449-1463 ◽  
Author(s):  
M R Siegrist ◽  
M A Dupertuis ◽  
R Behn ◽  
P D Morgan
Keyword(s):  
Magnetic Field ◽  
Temperature Measurement ◽  
Thomson Scattering ◽  
Ion Temperature

scholarly journals Experimental dynamics in magnetic field-driven flows compared to thermoconvective convection

2015 ◽  
Vol 373 (2056) ◽  
pp. 20150113 ◽  
Author(s):  
I. Cortés-Domínguez ◽  
J. Burguete ◽  
H. L. Mancini
Keyword(s):  
Magnetic Field ◽  
Surface Tension ◽  
Aspect Ratio ◽  
Rotational Symmetry ◽  
Temperature Gradients ◽  
Control Parameters ◽  
Large Drop ◽  
Experimental Control ◽  
Experimental Dynamics ◽  
Fluid Layers

We compare the dynamics obtained in two intermediate aspect ratio (diameter over height) experiments. These systems have rotational symmetry and consist of fluid layers that are destabilized using two different methods. The first one is a classical Bénard–Marangoni experiment, where the destabilizing forces, buoyancy and surface tension, are created by temperature gradients. The second system consists of a large drop of liquid metal destabilized using oscillating magnetic fields. In this configuration, the instability is generated by a radial Lorentz force acting on the conducting fluid. Although there are many important differences between the two configurations, the dynamics are quite similar: the patterns break the rotational symmetry, and different azimuthal and radial wavenumbers appear depending on the experimental control parameters. These patterns in most cases are stationary, but for some parameters they exhibit different dynamical behaviours: rotations, transitions between different solutions or cyclic connections between different patterns.

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