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Diffusion of charged particles in a stochastic magnetic field

Abstract

The diffusive motion of charged particles in a stochastic magnetic field is investigated systematically in a model in which the statistics of both the collisions and the magnetic field are described by coloured noises characterized, respectively, by a finite correlation time and finite correlation lengths. An analytic solution is obtained for the basic nonlinear differential equation of the model..It describes asymptotically a pure diffusion process, in which the mean square displacement in the perpendicular direction, {Gamma}(t), grows proportionally to time (after a sufficiently long time). The corresponding diffusion coefficient scales like the fourth power of the magnetic fluctuation intensity. The values obtained are in very good agreement with experimental data in reverse-field pinch experiments. The present result contradicts earlier results predicting subdiffusive behaviour: {Gamma}(t) {approx} t{sup 1/2} or {Gamma}(t) {approx} t{sup 1/4}. The relation of these results to ours is discussed in detail.
Publication Date:
Jul 01, 1992
Product Type:
Technical Report
Report Number:
EUR-CEA-FC-1463
Reference Number:
SCA: 700330; PA: AIX-24:009296; SN: 93000933689
Resource Relation:
Other Information: PBD: Jul 1992
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; PLASMA; DIFFUSION; ASYMPTOTIC SOLUTIONS; DIFFERENTIAL EQUATIONS; FLUCTUATIONS; MAGNETIC FIELDS; NONLINEAR PROBLEMS; PLASMA SIMULATION; 700330; PLASMA KINETICS, TRANSPORT, AND IMPURITIES
OSTI ID:
10119864
Research Organizations:
Association Euratom-CEA, Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee
Country of Origin:
France
Language:
English
Other Identifying Numbers:
Other: ON: TI93613686; TRN: FR9300238009296
Availability:
OSTI; NTIS (US Sales Only); INIS
Submitting Site:
FRN
Size:
[44] p.
Announcement Date:
Jun 30, 2005

Citation Formats

Balescu, R, Misguich, J H, and Nakach, R. Diffusion of charged particles in a stochastic magnetic field. France: N. p., 1992. Web.
Balescu, R, Misguich, J H, & Nakach, R. Diffusion of charged particles in a stochastic magnetic field. France.
Balescu, R, Misguich, J H, and Nakach, R. 1992. "Diffusion of charged particles in a stochastic magnetic field." France.
@misc{etde_10119864,
title = {Diffusion of charged particles in a stochastic magnetic field}
author = {Balescu, R, Misguich, J H, and Nakach, R}
abstractNote = {The diffusive motion of charged particles in a stochastic magnetic field is investigated systematically in a model in which the statistics of both the collisions and the magnetic field are described by coloured noises characterized, respectively, by a finite correlation time and finite correlation lengths. An analytic solution is obtained for the basic nonlinear differential equation of the model..It describes asymptotically a pure diffusion process, in which the mean square displacement in the perpendicular direction, {Gamma}(t), grows proportionally to time (after a sufficiently long time). The corresponding diffusion coefficient scales like the fourth power of the magnetic fluctuation intensity. The values obtained are in very good agreement with experimental data in reverse-field pinch experiments. The present result contradicts earlier results predicting subdiffusive behaviour: {Gamma}(t) {approx} t{sup 1/2} or {Gamma}(t) {approx} t{sup 1/4}. The relation of these results to ours is discussed in detail.}
place = {France}
year = {1992}
month = {Jul}
}