Statistical Formulation of Intermittency in Magnetized Plasmas
Lead Research Organisation:
University of Sheffield
Department Name: Applied Mathematics
Abstract
Coherent structures, such as large-scale shear flows, are common features in many physical systems. These structures play a crucial role in the mixing and transport of quantities like chemical impurities, momentum, etc. In particular, they may reduce the transport locally, forming a so-called transport barrier. The small-scale turbulence also affects the large scale structures, with this feedback leading to the possibility of self-regulation. Furthermore, coherent structures can cause fast (super-diffusive) transport by coherent advection as well as intermittency (coherent fluctuations above a uniformly random, Gaussian background). Due to the complexity of the resulting dynamics, a theory of the formation of these coherent structures and their impact on transport is far from complete. In particular, intermittency caused by coherent structures invalidates a traditional mean-field theory based on single (average) turbulent coefficients, and a proper description of turbulent transport demands statistical formulation.The aim of the proposed research programme is to advance the theoretical understanding of the effects of coherent structures on turbulent transport, with the specific objective of developing the statistical formulation of intermittency by using non-perturbative methods (beyond mean field theory). While the main focus is on the applications to laboratory plasmas, in view of its interdisciplinary nature, the outcome of the proposed research will no doubt have significant implications for many other fields (e.g. astrophysical, geophysical and space plasmas, Earth's atmosphere, meteorology, oceanography, and engineering problems), stimulating researches in those disciplines.
Organisations
People |
ORCID iD |
Eun-Jin Kim (Principal Investigator) |
Publications
Anderson J
(2008)
The momentum flux probability distribution function for ion-temperature-gradient turbulence
in Physics of Plasmas
Anderson J
(2008)
Nonperturbative models of intermittency in edge turbulence
in Physics of Plasmas
Anderson J
(2010)
Predicting PDF tails in systems with logarithmic non-linearity
in Physics Letters A
Kim E
(2010)
Intermittency and self-organization in turbulent flows
in Physica Scripta
Kim E
(2007)
Role of magnetic shear in flow shear suppression
in Physics of Plasmas
Kim E
(2009)
Probability distribution function for self-organization of shear flows
in Physics of Plasmas
Kim E
(2008)
Structure based statistical theory of intermittency
in Physics of Plasmas
KIM E
(2009)
Statistical Theory of Plasmas Turbulence
in Plasma and Fusion Research
Newton A
(2013)
On the self-organizing process of large scale shear flows
in Physics of Plasmas