U.S. Department of EnergyOffice of Scientific and Technical Information
The dynamics of marginality and self-organized criticality as a paradigm for turbulent transport
Abstract
A general paradigm, based on the concept of self-organized criticality (SOC), for turbulent transport in magnetically confined plasmas has been recently suggested as an explanation for some of the apparent discrepancies between most theoretical models of turbulent transport and experimental observations of the transport in magnetically confined plasmas. This model describes the dynamics of the transport without relying on the underlying local fluctuation mechanisms. Computations based on a cellular automata realization of such a model have found that noise driven SOC systems can maintain average profiles that are linearly stable (submarginal) and yet are able to sustain active transport dynamics. It is also found that the dominant scales in the transport dynamics in the absence of sheared flow are system scales rather than the underlying local fluctuation scales. The addition of sheared flow into the dynamics leads to a large reduction of the system-scale transport events and a commensurate increase in the fluctuation-scale transport events needed to maintain the constant flux. The dynamics of these models and the potential ramifications for transport studies are discussed.
- Authors:
-
- Oak Ridge National Lab., TN (United States)
- Univ. of California, San Diego, La Jolla, CA (United States)
- Princeton Univ., NJ (United States). Plasma Physics Lab.
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org.:
- USDOE, Washington, DC (United States)
- OSTI Identifier:
- 188629
- Report Number(s):
- CONF-951182-4
ON: DE96004930; TRN: 96:006372
- DOE Contract Number:
- AC05-84OR21400
- Resource Type:
- Conference
- Resource Relation:
- Conference: 37. annual meeting of the American Physical Society Division of Plasma Physics, Louisville, KY (United States), 6-10 Nov 1995; Other Information: PBD: [1995]
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION; THERMONUCLEAR DEVICES; TURBULENCE; TRANSPORT THEORY; MAGNETIC CONFINEMENT; PLASMA SIMULATION; SHEAR; PLASMA INSTABILITY; BOHM CRITERION
Citation Formats
Newman, D E, Carreras, B A, Diamond, P H, and Hahm, T S. The dynamics of marginality and self-organized criticality as a paradigm for turbulent transport. United States: N. p., 1995.
Web.
Newman, D E, Carreras, B A, Diamond, P H, & Hahm, T S. The dynamics of marginality and self-organized criticality as a paradigm for turbulent transport. United States.
Newman, D E, Carreras, B A, Diamond, P H, and Hahm, T S. 1995.
"The dynamics of marginality and self-organized criticality as a paradigm for turbulent transport". United States. https://www.osti.gov/servlets/purl/188629.
@article{osti_188629,
title = {The dynamics of marginality and self-organized criticality as a paradigm for turbulent transport},
author = {Newman, D E and Carreras, B A and Diamond, P H and Hahm, T S},
abstractNote = {A general paradigm, based on the concept of self-organized criticality (SOC), for turbulent transport in magnetically confined plasmas has been recently suggested as an explanation for some of the apparent discrepancies between most theoretical models of turbulent transport and experimental observations of the transport in magnetically confined plasmas. This model describes the dynamics of the transport without relying on the underlying local fluctuation mechanisms. Computations based on a cellular automata realization of such a model have found that noise driven SOC systems can maintain average profiles that are linearly stable (submarginal) and yet are able to sustain active transport dynamics. It is also found that the dominant scales in the transport dynamics in the absence of sheared flow are system scales rather than the underlying local fluctuation scales. The addition of sheared flow into the dynamics leads to a large reduction of the system-scale transport events and a commensurate increase in the fluctuation-scale transport events needed to maintain the constant flux. The dynamics of these models and the potential ramifications for transport studies are discussed.},
doi = {},
url = {https://www.osti.gov/biblio/188629},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Dec 31 00:00:00 EST 1995},
month = {Sun Dec 31 00:00:00 EST 1995}
}