Anomalous transport and stochastic processes
- Universite Libre de Bruxelles (Belgium)
The relation between kinetic transport theory and theory of stochastic processes is reviewed. The Langevin equation formalism provides important, but rather limited information about diffusive processes. A quite promising new approach to modeling complex situations, such as transport in incompletely destroyed magnetic surfaces, is provided by the theory of Continuous Time Random Walks (CTRW), which is presented in some detail. An academic test problem is discussed in great detail: transport of particles in a fluctuating magnetic field, in the limit of infinite perpendicular correlation length. The well-known subdiffusive behavior of the Mean Square Displacement (MSD), proportional to t{sup 1/2}, is recovered by a CTRW, but the complete density profile is not. However, the quasilinear approximation of the kinetic equation has the form of a non-Markovian diffusion equation and can thus be generated by a CTRW. 16 refs., 3 figs.
- OSTI ID:
- 249593
- Report Number(s):
- CONF-9509335-; ISSN 0748-1896; TRN: 96:003806-031
- Journal Information:
- Fusion Technology, Vol. 29, Issue 2T; Conference: 2. Carolus Magnus summer school on plasma physics, Aachen (Germany), 11-22 Sep 1995; Other Information: PBD: Mar 1996
- Country of Publication:
- United States
- Language:
- English
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