Effects of plasma turbulence on electron collection by a high-voltage spherical probe in a magnetized plasma

1992 ◽  
Vol 97 (A5) ◽  
pp. 6493 ◽  
Author(s):  
P. J. Palmadesso ◽  
G. Ganguli
Keyword(s):  
High Voltage ◽  
Plasma Turbulence ◽  
Magnetized Plasma ◽  
Spherical Probe ◽  
Electron Collection

A phenomenological theory of drift wave type plasma turbulence

1979 ◽  
Vol 21 (3) ◽  
pp. 423-429 ◽  
Author(s):  
Amiya K. Sen
Keyword(s):  
Phenomenological Theory ◽  
Plasma Turbulence ◽  
Magnetized Plasma ◽  
Wave Type ◽  
Hydrodynamic Turbulence ◽  
Drift Wave ◽  
Kolmogorov Spectrum ◽  
Strong Turbulence

A phenomenological theory of drift type turbulence in inhomogeneous magnetized plasma is developed in the spirit of the Kolmogorov spectrum of hydrodynamic turbulence. We model the spectrum in terms of subspectra: production, equilibrium and dissipation. Different nonlinearities and either weak or strong turbulence characterize different subspectra.

A soliton gas model for astrophysical magnetized plasma turbulence

1982 ◽  
Vol 257 ◽  
pp. 855 ◽  
Author(s):  
S. R. Spangler ◽  
J. P. Sheerin
Keyword(s):  
Plasma Turbulence ◽  
Magnetized Plasma

scholarly journals Fluidization of collisionless plasma turbulence

2019 ◽  
Vol 116 (4) ◽  
pp. 1185-1194 ◽  
Author(s):  
Romain Meyrand ◽  
Anjor Kanekar ◽  
William Dorland ◽  
Alexander A. Schekochihin
Keyword(s):  
Solar Wind ◽  
Power Law ◽  
Collisionless Plasma ◽  
Plasma Turbulence ◽  
Magnetized Plasma ◽  
Landau Damping ◽  
Astrophysical Plasmas ◽  
Phase Mixing ◽  
Fluid Turbulence ◽  
Collisionless Plasmas

In a collisionless, magnetized plasma, particles may stream freely along magnetic field lines, leading to “phase mixing” of their distribution function and consequently, to smoothing out of any “compressive” fluctuations (of density, pressure, etc.). This rapid mixing underlies Landau damping of these fluctuations in a quiescent plasma—one of the most fundamental physical phenomena that makes plasma different from a conventional fluid. Nevertheless, broad power law spectra of compressive fluctuations are observed in turbulent astrophysical plasmas (most vividly, in the solar wind) under conditions conducive to strong Landau damping. Elsewhere in nature, such spectra are normally associated with fluid turbulence, where energy cannot be dissipated in the inertial-scale range and is, therefore, cascaded from large scales to small. By direct numerical simulations and theoretical arguments, it is shown here that turbulence of compressive fluctuations in collisionless plasmas strongly resembles one in a collisional fluid and does have broad power law spectra. This “fluidization” of collisionless plasmas occurs, because phase mixing is strongly suppressed on average by “stochastic echoes,” arising due to nonlinear advection of the particle distribution by turbulent motions. Other than resolving the long-standing puzzle of observed compressive fluctuations in the solar wind, our results suggest a conceptual shift for understanding kinetic plasma turbulence generally: rather than being a system where Landau damping plays the role of dissipation, a collisionless plasma is effectively dissipationless, except at very small scales. The universality of “fluid” turbulence physics is thus reaffirmed even for a kinetic, collisionless system.

scholarly journals Comparative study of the surface potential of magnetic and non-magnetic spherical objects in a magnetized radio-frequency discharge

2020 ◽  
Vol 86 (5) ◽  
Author(s):  
Mangilal Choudhary ◽  
Roman Bergert ◽  
Slobodan Mitic ◽  
Markus H. Thoma
Keyword(s):  
Magnetic Field ◽  
Surface Potential ◽  
Debye Length ◽  
Rate Of Change ◽  
Magnetized Plasma ◽  
Dust Particles ◽  
Capacitively Coupled ◽  
Spherical Probe ◽  
Field Diffusion ◽  
Magnetic Sphere

We report measurements of the time-averaged surface floating potential of magnetic and non-magnetic spherical probes (or large dust particles) immersed in a magnetized capacitively coupled discharge. In this study, the size of the spherical probes is taken greater than the Debye length. The surface potential of a spherical probe first increases, i.e. becomes more negative at low magnetic field ( $B < 0.05\ \textrm {T}$ ), attains a maximum value and decreases with further increase of the magnetic field strength ( $B > 0.05\ \textrm {T}$ ). The rate of change of the surface potential in the presence of a $B$ -field mainly depends on the background plasma and types of material of the objects. The results show that the surface potential of the magnetic sphere is higher (more negative) compared with the non-magnetic spherical probe. Hence, the smaller magnetic sphere collects more negative charges on its surface than a bigger non-magnetic sphere in a magnetized plasma. The different sized spherical probes have nearly the same surface potential above a threshold magnetic field ( $B > 0.03\ \textrm {T}$ ), implying a smaller role of size dependence on the surface potential of spherical objects. The variation of the surface potential of the spherical probes is understood on the basis of a modification of the collection currents to their surface due to charge confinement and cross-field diffusion in the presence of an external magnetic field.

Sign in / Sign up

Export Citation Format

Share Document