scholarly journals Bernstein mode acceleration of electrons in a magnetic mirror

2020 ◽  
Vol 38 (2) ◽  
pp. 79-83
Author(s):  
Ram Jeet ◽  
Asheel Kumar
Keyword(s):  
Magnetic Field ◽  
Transverse Energy ◽  
Mode Conversion ◽  
Magnetic Mirror ◽  
Electron Dynamics ◽  
Linear Mode ◽  
Gain Energy ◽  
Normalized Parameters ◽  
Electron Cyclotron Wave ◽  
Bernstein Wave

AbstractElectron dynamics in an axially localized large amplitude electron Bernstein mode in a magnetic mirror is studied. The mode is localized due to plasma density and magnetic field profiles and could be driven by an electron cyclotron wave, launched from outside, via linear mode conversion. Energetic electrons of finite gyro-radius resonantly interact with the mode and gain primarily transverse energy favoring stronger mirror confinement. At Bernstein wave normalized amplitude of A00 = 0.01 and for other normalized parameters Zn0 = 40, k⊥c/ω = 10, ${L}^{\prime}_m = 215$, ωc0/ω = 0.9, ψn0 = 3π/2, the electrons can gain energy in the hundreds of keV range.

Self-consistent treatment of cyclotron resonances in inhomogeneous plasmas

1990 ◽  
Vol 43 (1) ◽  
pp. 151-163 ◽  
Author(s):  
B. M. Harvey ◽  
E. W. Laing
Keyword(s):  
Magnetic Field ◽  
Mode Conversion ◽  
Magnetic Field Gradient ◽  
Process Conditions ◽  
Fast Wave ◽  
Linear Mode ◽  
Consistent Treatment ◽  
Bernstein Wave ◽  
The Magnetic Field ◽  
Transmission And Reflection

The wave differential operator is obtained directly from the perturbed Vlasov equation for an inhomogeneous equilibrium magnetic field including consistently the effects of strong wave damping and linear mode conversion. In the process, conditions on the parallel wavenumber and the magnetic-field gradient for which such a method is valid are obtained. From these equations it is shown that the inclusion of parameter-gradient terms arising from the spatial dependence of the equilibrium magnetic field is important for accurate calculation of mode conversion from fast to ion-Bernstein wave, although the dispersion-relation-based operator can be sufficient to describe transmission and reflection of the fast wave. Finally, the coupled second-order equations used by Fuchs & Bers (1988) are obtained, allowing direct identification of the ‘modes’ referred to in that paper in terms of components of the electric field. By reconciling these two different approaches, some insight is gained into the mode-conversion process.

scholarly journals Charged particle acceleration by electron Bernstein wave in a plasma channel

2010 ◽  
Vol 28 (3) ◽  
pp. 409-414 ◽  
Author(s):  
Asheel Kumar ◽  
Binod K. Pandey ◽  
V.K. Tripathi
Keyword(s):  
Magnetic Field ◽  
Particle Acceleration ◽  
Electron Beam ◽  
Electromagnetic Wave ◽  
Plasma Channel ◽  
Mode Conversion ◽  
Transverse Field ◽  
Gaussian Profile ◽  
Relativistic Mass ◽  
Bernstein Wave

AbstractA model of electron acceleration by an electron Bernstein mode in a parabolic density profile is developed. The mode has a Gaussian profile. It could be excited via the mode conversion of an electromagnetic wave or by an electron beam. As it attains a large amplitude, it axially traps electrons moving close to its parallel phase velocity, where parallel refers to the direction of static magnetic field. As the electrons are accelerated and tend to get out of phase with the wave, the transverse field of the mode enhances its energy and relativistic mass, increasing the dephasing length. The scheme can produce electron energies up to a few MeV.

scholarly journals Simulation of mode conversion process from upper-hybrid waves to LO-mode waves in the vicinity of the plasmapause

2010 ◽  
Vol 28 (6) ◽  
pp. 1289-1297 ◽  
Author(s):  
M. J. Kalaee ◽  
Y. Katoh ◽  
A. Kumamoto ◽  
T. Ono ◽  
Y. Nishimura
Keyword(s):  
Density Gradient ◽  
Electric Fields ◽  
Numerical Experiments ◽  
Mode Conversion ◽  
Equatorial Region ◽  
Magnetized Plasma ◽  
Conversion Process ◽  
Observation Data ◽  
Linear Mode ◽  
Wave Normal

Abstract. In order to clarify the role of the mode conversion process in the generation mechanism of LO-mode waves in the equatorial region of the plasmasphere, we have investigated the linear mode conversion process among upper-hybrid-resonance (UHR)-mode, Z-mode and LO-mode waves by a numerical simulation solving Maxwell's equations and the equation of motion of a cold electron fluid. The wave coupling process occurring in the cold magnetized plasma are examined in detail. In order to give a realistic initial plasma condition in the numerical experiments, we use initial parameters inferred from observation data obtained around the generation region of LO-mode waves obtained by the Akebono satellite. A density gradient is estimated from the observed UHR frequency, and wave normal angles are estimated from the dispersion relation of cold plasma by comparing observed wave electric fields. Then, we perform numerical experiments of mode conversion processes using the density gradient of background plasma and the wave normal angle of incident upper hybrid mode waves determined from the observation results. We found that the characteristics of reproduced LO-mode waves in each simulation run are consistent with observations.

Experimental study of force-free, collinear plasma structures

1973 ◽  
Vol 9 (1) ◽  
pp. 1-15 ◽  
Author(s):  
E. E. Nolting ◽  
P. E. Jindra ◽  
D. R. Wells
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Magnetic Fields ◽  
Flow Fields ◽  
Diagnostic Techniques ◽  
Field Configuration ◽  
Magnetic Mirror ◽  
Magnetic Field Configuration ◽  
Magnetic Barrier ◽  
Magnetic Well

Detailed measurements of the trapped magnetic fields and currents in plasma structures generated by conical theta-pinches are reported. Studies of these structures interacting with a magnetic barrier, and with each other in a collision at the centre of a magnetic mirror, are reported. The magnetic well formed by the collision has been studied by simultaneous use of several diagnostic techniques. The measurements are in agreement with a force-free, collinear magnetic field configuration (Wells 1972). Arguments relating superposability and collinearity of flow fields to these observations are given.

Chaotic electron dynamics in antidot lattice subjected to strong in-plane magnetic field

2002 ◽  
Vol 66 (3) ◽  
Author(s):  
N. M. Sotomayor Choque ◽  
G. M. Gusev ◽  
J. R. Leite ◽  
A. A. Bykov ◽  
L. V. Litvin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Dynamics

Four-dimensional eikonal theory of linear mode conversion

1987 ◽  
Vol 58 (14) ◽  
pp. 1392-1394 ◽  
Author(s):  
Lazar Friedland ◽  
Galya Goldner ◽  
Allan N. Kaufman
Keyword(s):  
Mode Conversion ◽  
Linear Mode
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