The dynamics of marginality and self-organized criticality as a paradigm for turbulent transport

Newman, D. E.; Carreras, B. A.; Diamond, P. H.; Hahm, T. S.

doi:10.1063/1.871681

Cited by 222 publications

(206 citation statements)

References 14 publications

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“…It is difficult to understand how a dynamical system containing a strongly turbulent key component can ex-hibit indications of low dimensional behavior. But Chang (1992Chang ( , 1998Chang ( , 1999 has shown that this is exactly the behavior to be expected from a system in self-organization and studies of turbulent transport in magnetically confined plasmas have confirmed this (Diamond and Hahm, 1995;Newman et al, 1996;Carreras et al, 1996).…”

Section: Complexity In the Magnetospherementioning

confidence: 76%

The magnetosphere as a complex system

Valdivia

Rogan

Muñoz

et al. 2005

Advances in Space Research

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The magnetosphere is a complex system, with multi-scale spatio-temporal behavior. Self-organization is a possible solution to two seemingly contradicting observations: (a) the repeatable and coherent substorm phenomena, and, (b) the underlying selfsimilar turbulent behavior in the plasma sheet. Such states, are seen to emerge naturally in a plasma physics model with sporadic dissipation, through spatio-temporal chaos.

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Section: Complexity In the Magnetospherementioning

confidence: 76%

The magnetosphere as a complex system

Valdivia

Rogan

Muñoz

et al. 2005

Advances in Space Research

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“…Consequently, for weakly unstable states, the problem of studying the dynamics of our model consists in finding an approximate equation for the dynamics of U, E and N being determined at the end of the day from the slaving conditions (20), (18). The form of the reduced equation for U is quite different for µ 1 = 0 and µ 1 = 0.…”

Section: Dynamics Near Marginal Stabilitymentioning

confidence: 99%

“…For the same reason, the range of plasma parameters considered is not yet in an L-mode regime. Therefore, we do not expect avalanche-like transport [19,20] and the transport terms can be represented by purely diffusive terms. Concretely, we discuss an extension to 1-D of the original model used in comparison with the experimental data [11].…”

Section: Introductionmentioning

confidence: 99%

Dynamics of a one-dimensional model for the emergence of the plasma edge shear flow layer with momentum-conserving Reynolds stress

Calvo¹,

Carreras²

2007

Physics of Plasmas

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A one-dimensional version of the second-order transition model based on the sheared flow amplification by Reynolds stress and turbulence supression by shearing is presented. The model discussed in this paper includes a form of the Reynolds stress which explicitly conserves momentum. A linear stability analysis of the critical point is performed. Then, it is shown that the dynamics of weakly unstable states is determined by a reduced equation for the shear flow. In the case in which the flow damping term is diffusive, the stationary solutions are those of the real Ginzburg-Landau equation.

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“…SGT has wide applicability [5,6] including type III solar radio bursts [5], magnetospheric Langmuir, beam and z-mode waves [7], and pulsar emissions [8], plus a range of quasilinear, particle-in-cell, and other simulations [6]. Evidence for other statistical plasma theories, such as SOC, has been found in solar flares and the intermittent turbulence of the Earth's magnetotail [9][10][11] and it has been invoked to describe confinement and transport phenomena in magnetically confined plasmas [12,13].These successes motivate searching for new applications of statistical plasma theories. In this Letter we perform a statistical analysis of fluctuations in a laboratory plasma and find lognormal distributions over a wide range of field strength, the first laboratory evidence for an SGT state.…”

mentioning

confidence: 99%

Laboratory Evidence for Stochastic Plasma-Wave Growth

Austin

Hole²,

Robinson³

et al. 2007

Phys. Rev. Lett.

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The first laboratory confirmation of stochastic growth theory is reported. Floating potential fluctuations are measured in a vacuum arc centrifuge using a Langmuir probe. Statistical analysis of the energy density reveals a lognormal distribution over roughly 2 orders of magnitude, with a high-field nonlinear cutoff whose spatial dependence is consistent with the predicted eigenmode profile. These results are consistent with stochastic growth and nonlinear saturation of a spatially extended eigenmode, the first evidence for stochastic growth of an extended structure. Statistical plasma theories, such as stochastic growth theory [1,2] (SGT) and self-organized criticality (SOC) [3,4], have enjoyed wide success in describing nonuniform fluctuations in complex systems. In particular, complex initial and/or boundary conditions, sources, and sinks of energy, and nonlinear evolution can lead to a highly nonuniform plasma structure in a state of dynamical equilibrium. In these systems, textbook models of wave growth that assume simply structured initial conditions offer little insight into emergent properties such as marginal stability. In contrast, statistical plasma theories connect the salient features of the wave physics to characteristic distributions of wave properties. For example, in SGT a randomly varying wave growth rate leads to a lognormal distribution, in SOC ''sandpile avalanche'' type behavior yields scalefree power-law distributions, while Gaussians are expected in many contexts. SGT has wide applicability [5,6] including type III solar radio bursts [5], magnetospheric Langmuir, beam and z-mode waves [7], and pulsar emissions [8], plus a range of quasilinear, particle-in-cell, and other simulations [6]. Evidence for other statistical plasma theories, such as SOC, has been found in solar flares and the intermittent turbulence of the Earth's magnetotail [9][10][11] and it has been invoked to describe confinement and transport phenomena in magnetically confined plasmas [12,13].These successes motivate searching for new applications of statistical plasma theories. In this Letter we perform a statistical analysis of fluctuations in a laboratory plasma and find lognormal distributions over a wide range of field strength, the first laboratory evidence for an SGT state. Also, a departure from lognormality at high-field strengths is shown to be consistent with nonlinear saturation of a spatially extended eigenmode structure.The device used to obtain the data is a vacuum arc centrifuge (VAC), a magnetized plasma device originally designed to separate nuclear isotopes. It uses an arc discharge to form a multiply ionized (Z > 1) low temperature (T 6 10 4 K) high density (n i 10 18 m ÿ3 ) Mg plasma. The plasma is situated in an axial magnetic field (B 0:1 T) and is formed by drawing a 1 kA arc between a metal cathode and a wire mesh anode 60 mm distant. As the return current passes through the mesh, resistive losses generate a radial electric field. The interaction of the resultant radial current with the axial magne...

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The dynamics of marginality and self-organized criticality as a paradigm for turbulent transport

Abstract: Abstract

Cited by 222 publications

References 14 publications

The magnetosphere as a complex system

The magnetosphere as a complex system

Dynamics of a one-dimensional model for the emergence of the plasma edge shear flow layer with momentum-conserving Reynolds stress

Laboratory Evidence for Stochastic Plasma-Wave Growth

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