scholarly journals Solenoidal Excitation of Eigenmodes in Cylindrical Magnetized Plasma with Two Ion Species

1983 ◽  
Vol 36 (4) ◽  
pp. 491 ◽  
Author(s):  
TD Kieu ◽  
WN-C Sy

The conditions for the experimental observation of new types of eigenmodes in a typical laboratory magnetized plasma with two ion species are discussed. It is shown that the most favourable condition occurs during the current carrying phase of the discharge, with an appropriately chosen mixture of ions.


2018 ◽  
Vol 84 (3) ◽  
Author(s):  
Michael Barnes ◽  
P. Abiuso ◽  
W. Dorland

Observational evidence in space and astrophysical plasmas with a long collisional mean free path suggests that more massive charged particles may be preferentially heated. One possible mechanism for this is the turbulent cascade of energy from injection to dissipation scales, where the energy is converted to heat. Here we consider a simple system consisting of a magnetized plasma slab of electrons and a single ion species with a cross-field density gradient. We show that such a system is subject to an electron drift wave instability, known as the universal instability, which is stabilized only when the electron and ion thermal speeds are equal. For unequal thermal speeds, we find from quasilinear analysis and nonlinear simulations that the instability gives rise to turbulent energy exchange between ions and electrons that acts to equalize the thermal speeds. Consequently, this turbulent heating tends to equalize the component temperatures of pair plasmas and to heat ions to much higher temperatures than electrons for conventional mass-ratio plasmas.



1986 ◽  
Vol 28 (8) ◽  
pp. 1043-1054 ◽  
Author(s):  
N F Cramer ◽  
C -M Yung


1986 ◽  
Vol 36 (3) ◽  
pp. 313-328 ◽  
Author(s):  
F. Cozzani ◽  
W. Horton

The transport theory of a high-energy ion species injected isotropically in a magnetized plasma is considered for arbitrary ratios of the high-energy ion cyclotron frequency to the collisional slowing down time. The assumptions of (i) low fractional density of the high-energy species and (ii) average ion speed faster than the thermal ions and slower than the electrons are used to decouple the kinetic equation for the high-energy species from the kinetic equations for background ions and electrons. The kinetic equation is solved by a Chapman–Enskog expansion in the strength of the gradients; an equation for the first correction to the lowest-order distribution function is obtained without scaling a priori the collision frequency with respect to the gyrofrequency. Various transport coefficients are explicitly calculated for the two cases of a weakly and a strongly magnetized plasma.



2002 ◽  
Vol 89 (6) ◽  
Author(s):  
N. Yugami ◽  
T. Higashiguchi ◽  
H. Gao ◽  
S. Sakai ◽  
K. Takahashi ◽  
...  


Author(s):  
Atit Deuja ◽  
Suresh Basnet ◽  
Raju Khanal

Abstract Fluid theory has been employed to investigate the magnetized plasma-wall transition properties for two ion species plasmas with a uniform background of neutral gas density in the presence of an external magnetic field. The external applied magnetic field is parallel to the surface and its magnitude varies in the direction perpendicular to the surface. The governing equations of ion and electron fluids include ionization and collision with neutral atoms. A comparative study of transition parameters for non-uniform and uniform magnetic fields is performed at equal values of the magnetic flux density at $x = 0$. This study shows that the sheath region shrinks for the non-uniform magnetic field case, essentially in reason of the lower value of the average magnetic field intensity in the plasma-wall transition region. We introduce a figure of merit to quantify the non-uniformity of the magnetic field $(B_{\mathrm{max}}-B_{\mathrm{min}})/B_{\mathrm{max}}$, and show that for its value 0.21 it is possible to model the plasma-wall transition region considering the magnetic field as uniform and equal to its average value. Furthermore, we find that the density distribution of electrons close to the surface deviates from the Boltzmann distribution due to the influence of a strong magnetic field.



1995 ◽  
Vol 53 (2) ◽  
pp. 127-133 ◽  
Author(s):  
M. Bose

Stimulated Brillouin scattering of an electromagnetic wave is investigated analytically in a dissipative magnetized plasma in the presence of negative ions. With an increase in the number of negative ions (maintaining quasi-neutrality), it is found that the growth rate of ion-acoustic waves decreases very slowly up to 50% concentration (i.e. half of the total ionic contribution) of negative ions. Further increase in the number density of negative ions beyond 50% results in a sharp fall in growth rate.



2013 ◽  
Vol 79 (5) ◽  
pp. 949-952 ◽  
Author(s):  
M. ROSENBERG ◽  
R. L. MERLINO

AbstractDrift wave instability in a magnetized plasma composed of positive ions and negative ions is considered using linear kinetic theory in the local approximation. We consider the case where the mass (temperature) of the negative ions is much larger (smaller) than that of the positive ions, and where the gyroradii of the two ion species are comparable. Weak collisional effects are taken into account. Application to possible laboratory parameters is discussed.





2019 ◽  
Vol 85 (1) ◽  
Author(s):  
Frank Verheest ◽  
Manfred A. Hellberg

The plasma model used in a recent paper by Kamalam et al. (J. Plasma Phys., vol. 84, 2018, 905840406) assumes a Boltzmann description for two hot ion species, in the presence of two adiabatic (fluid) electron species, for the study of obliquely propagating acoustic-type nonlinear solitary waves with respect to a static magnetic field. We argue that the assumption of Boltzmann distributions for the hot ions is incorrect, thus invalidating their conclusions, in particular about the possible occurrence of supersolitons in magnetized plasmas.



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Devshree Mandal ◽  
Ayushi Vashistha ◽  
Amita Das

AbstractAn electromagnetic (EM) pulse falling on a plasma medium from vacuum can either reflect, get absorbed or propagate inside the plasma depending on whether it is overdense or underdense. In a magnetized plasma, however, there are usually several pass and stop bands for the EM wave depending on the orientation of the magnetic field with respect to the propagation direction. The EM wave while propagating in a plasma can also excite electrostatic disturbances in the plasma. In this work Particle-In-Cell simulations have been carried out to illustrate the complete transparency of the EM wave propagation inside a strongly magnetized plasma. The external magnetic field is chosen to be perpendicular to both the wave propagation direction and the electric field of the EM wave, which is the X mode configuration. Despite the presence of charged electron and ion species the plasma medium behaves like a vacuum. The observation is understood with the help of particle drifts. It is shown that though the two particle species move under the influence of EM fields their motion does not lead to any charge or current source to alter the dispersion relation of the EM wave propagating in the medium. Furthermore, it is also shown that the stop band for EM wave in this regime shrinks to a zero width as both the resonance and cut-off points approach each other. Thus, transparency to the EM radiation in such a strongly magnetized case appears to be a norm.



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