Eur. Phys. J. D 65, 429-440 (2011)
https://doi.org/10.1140/epjd/e2011-10464-2

Regular Article

Dependences of the drift velocity of electrons and the magnetoresistance effect on the ionization-degrees and the active radii of the Coulomb force of an ion sphere in an intermediately ionized plasma of a helium gas

Nippon Electronic Engineering College, Satunai-cho, Noboribetsu-shi, Hokkaido, Japan

^a e-mail: nagata@heian-kogyo.jp

Received: 23 August 2010
Received in final form: 17 January 2011
Published online: 1 December 2011

Abstract

Two weakly ionized plasmas (the ionization-degree a′′ = 10^-6 and 10^-5) and an intermediately ionized plasma (a′′ = 10^-4) are investigated. In previous work, the negative magnetoresistance effect (the increase-phenomenon of the discharge current) in a gas plasma in the case where electrons are scattered only by heavy neutral atoms was only touched upon. In this work, under the condition that electrons are scattered by heavy neutral atoms and by the Coulomb force of heavy helium ions, the dependences of “the drift velocity of electrons” and “the increase-phenomenon of the discharge current in the magnetoresistance effect” on the ionization-degrees and the active radii of the Coulomb force of a helium ion are examined. And it is pointed out that the increase-phenomenon of the discharge current in the magnetoresistance effect appears from neither the wellknown Langevin equation nor the Fokker-Planck equation.