Electron distribution function in an electron-beam plasma

The influence of a highly energetic electron beam on the electron distribution function (e.d.f.) in a hot dense plasma is investigated by solving the Boltzmann equation analytically. A plateau is obtained in the tail of the e.d.f. over an energy range between the excitation threshold and an energy value half that of the monoenergetic electrons. The importance of this plateau is discussed for a dense He-like argon plasma.

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Electrostatic heat flux instabilities

Journal of Plasma Physics ◽

10.1017/s0022377800021358 ◽

1978 ◽

Vol 20 (1) ◽

pp. 47-60 ◽

Cited By ~ 24

Author(s):

S. Peter Gary

Keyword(s):

Heat Flux ◽

Distribution Function ◽

Electron Beam ◽

Electron Distribution ◽

Electron Distribution Function ◽

High Energy ◽

Electrostatic Waves ◽

High Energy Tail ◽

Ion Acoustic ◽

Ion Cyclotron

The linear Vlasov dispersion relation for electrostatic waves in a homogeneous plasma is studied for instabilities driven by an electron heat flux. A two Maxwellian model of the electron distribution function gives rise to three unstable modes: the electron beam, ion-acoustic and ion cyclotron heat flux instabilities. At large Te/Ti the ion-acoustic instability has the lowest threshold; at small Te/Ti the electron beam instability is dominant; and at intermediate values of Te/Ti the ion cyclotron mode is the first to go unstable. The presence of a high energy tail on the electron distribution function raises the value of the dimensionless heat flux qe/(nemev3e) at the ion-acoustic threshold, but increasing atomic number of the ions decreases this value.

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Electron distribution function in electron‐beam‐excited plasmas

Applied Physics Letters ◽

10.1063/1.88885 ◽

1976 ◽

Vol 29 (1) ◽

pp. 7-9 ◽

Cited By ~ 2

Author(s):

C. A. Brau

Keyword(s):

Distribution Function ◽

Electron Beam ◽

Electron Distribution ◽

Electron Distribution Function

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Thermalization of a beam by beam-plasma interaction

Journal of Plasma Physics ◽

10.1017/s0022377800026106 ◽

1975 ◽

Vol 13 (2) ◽

pp. 349-360 ◽

Cited By ~ 8

Author(s):

J. H. A. Van Wakeren ◽

H. J. Hopman

Keyword(s):

Distribution Function ◽

Electron Beam ◽

Electric Field ◽

Plasma Column ◽

Numerical Calculations ◽

Plasma Interaction ◽

Type Distribution ◽

Beam Plasma ◽

Plasma Distribution ◽

Electron Beam Plasma

We present measurements proving the successive excitation of two distinct instabilities by electron beam–plasma interaction along a plasma column. The first, appearing near the gun, grows in space, until the beam is trapped in the wave electric field, and decays. In this process the time-averaged distribution function changes, from a δ-type distribution function, into a plateau. This new beam–plasma distribution is also unstable; and another instability grows until the beam is again trapped. Numerical calculations show that the second instability can be explained, assuming that the beam distribution thermalizes when propagating from the first instability to the second.

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Return-current formation in the electron beam – plasma system

Nonlinear Processes in Geophysics ◽

10.5194/npg-16-525-2009 ◽

2009 ◽

Vol 16 (4) ◽

pp. 525-532 ◽

Cited By ~ 10

Author(s):

M. Karlický ◽

M. Bárta

Keyword(s):

Distribution Function ◽

Magnetic Fields ◽

Electron Distribution ◽

Cell Model ◽

Electron Distribution Function ◽

Beam Propagation ◽

Propagation Direction ◽

Plasma System ◽

Return Current ◽

Beam Plasma

Abstract. Using a 3-D electromagnetic particle-in-cell model an evolution of the electron distribution function in the beam-plasma system with the return current is computed. It was found that the resulting electron distribution function depends on the magnetic field assumed along the beam-propagation direction. While for small magnetic fields the electron distribution function becomes broad in the direction perpendicular to the beam propagation due to the Weibel (filamentation) instability and the return current is formed by a shifted bulk distribution, for stronger magnetic fields the distribution, especially on the return current side, is extended in the beam-propagation direction. To understand better the instabilities influencing the mentioned processes, the dispersion diagrams are computed and discussed.

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