Theory of runaway electrons in a Lorentz plasma

A formal method of multiple scales is used to study the effect of a harmonically varying applied uniform electric field, of magnitude much smaller than the Dreicer critical field Ec, on the runaway electrons in a Lorentz plasma.

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Experimental Study on the Movement of Conducting Spheroidal Particles under Electric Field in Air

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.781.351 ◽

2015 ◽

Vol 781 ◽

pp. 351-354

Author(s):

Tatchawin Sangsri ◽

Viet Quoc Huynh ◽

Boonchai Techaumnat

Keyword(s):

Electric Field ◽

Critical Field ◽

Contact Point ◽

Uniform Electric Field ◽

Prolate Spheroidal ◽

Voltage Polarity ◽

Insulation Systems ◽

Conducting Particle ◽

Experimental Values ◽

Measured Particle

Study on the movement of conducting particle is useful for managing particles in gas insulation systems. The authors observed the movement of conducting prolate spheroidal particles under uniform electric field in air. From the experimental results we found three patterns of the movement. The critical electric field results in particle rotating or lifting. The particles rotated about the contact point before lifting in most cases. The measured particle-rotating field was lower than the analytical ones by 6 and 21% for 9 and 18 mm gaps, respectively. From the experiment, the size of the particles and the gap distance affect the critical field. The voltage polarity has no effect on the critical field for particle movement because of little difference between the experimental values of positive and negative polarities.

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Nonlinear electrohydrodynamic Kelvin–Helmholtz instability conditions of an interface between two fluids under the effect of a normal periodic electric field

Canadian Journal of Physics ◽

10.1139/p90-076 ◽

1990 ◽

Vol 68 (6) ◽

pp. 479-494 ◽

Cited By ~ 1

Author(s):

E. F. El Shehawey ◽

N. R. Abd El Gawaad

Keyword(s):

Differential Equation ◽

Electric Field ◽

Multiple Scales ◽

Method Of Multiple Scales ◽

Mathieu Equation ◽

Second Order ◽

Surface Charges ◽

Helmholtz Instability ◽

Order Problem ◽

Two Fluids

The electrohydrodynamic Kelvin–Helmholtz instability conditions of an interface separating two dielectric streaming fluids, stressed by a normal electric field in absence of surface charges on the interface, are studied. We use the method of multiple scales to solve nonlinear equations. In the first-order problem we obtained Mathieu's differential equation. For the second-order problem, we obtain the nonhomogeneous Mathieu equation and we use the method of multiple scales to obtain a sequence of equations. In the third-order problem, we obtain the second-order differential equation of periodic coefficients; we also obtain a formula for surface elevation, and we determine the instability conditions.

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Suppression of runaway of electrons in a Lorentz plasma.: I. Harmonically time varying electric field

Journal of Plasma Physics ◽

10.1017/s0022377800005079 ◽

1970 ◽

Vol 4 (2) ◽

pp. 387-402 ◽

Cited By ~ 4

Author(s):

Barbara Abraham-Shrauner

Keyword(s):

Electric Field ◽

High Frequency ◽

Particle Distribution ◽

Collision Frequency ◽

Uniform Electric Field ◽

Perturbation Scheme ◽

Time Varying ◽

Runaway Electrons ◽

Two Component ◽

Zero Frequency

The suppression of runaway electrons in a Lorentz plasma is demonstrated for a two-component, fully ionized plasma in the presence of a high frequency, weak, uniform electric field. The time for runaway to occur for electric field frequencies high compared to the collision frequency is longer than the runaway time for low electric field frequencies or zero frequency, by the ratio of the frequency of the electric field to the collision frequency squared. Both the resolvant method developed by Prigogine and co-workers and the double perturbation scheme of the Poincaré—Lighthill method are employed to derive the diffusion equation for the modified one-particle distribution function in the collision-dominated region of velocity space.

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