Aspects of Anomalous Transport in Plasmas

Aspects of Anomalous Transport in Plasmas PDF Author: Radu Balescu
Publisher: CRC Press
ISBN: 9781420034684
Category : Science
Languages : en
Pages : 498

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Book Description
Anomalous transport is a ubiquitous phenomenon in astrophysical, geophysical and laboratory plasmas; and is a key topic in controlled nuclear fusion research. Despite its fundamental importance and ongoing research interest, a full understanding of anomalous transport in plasmas is still incomplete, due to the complexity of the nonlinear phenomena involved. Aspects in Anomalous Transport in Plasmas is the first book to systematically consider anomalous plasma transport theory and provides a unification of the many theoretical models by emphasizing interrelations between seemingly different methodologies. It is not intended as a catalogue of the vast number of plasma instabilities leading to anomalous transport; instead it chooses a number of these and emphasizes the aspects specifically due to turbulence. After a brief introduction, the microscopic theory of turbulence is discussed, including quasilinear theory and various aspects of renormalization methods, which leads to an understanding of resonance broadening, mode coupling, trajectory correlation and clumps. The second half of the book is devoted to stochiastic tramsport, using methods based on the Langevin equations and on Random Walk theory. This treatment aims at going beyond the traditional limits of weak turbulence, by introducing the recently developed method of decorrelation trajectories, and its application to electrostatic turbulence, magnetic turbulence and zonal flow generation. The final chapter includes very recent work on the nonlocal transport phenomenon.

Aspects of Anomalous Transport in Plasmas

Aspects of Anomalous Transport in Plasmas PDF Author: Radu Balescu
Publisher: CRC Press
ISBN: 9781420034684
Category : Science
Languages : en
Pages : 498

Get Book Here

Book Description
Anomalous transport is a ubiquitous phenomenon in astrophysical, geophysical and laboratory plasmas; and is a key topic in controlled nuclear fusion research. Despite its fundamental importance and ongoing research interest, a full understanding of anomalous transport in plasmas is still incomplete, due to the complexity of the nonlinear phenomena involved. Aspects in Anomalous Transport in Plasmas is the first book to systematically consider anomalous plasma transport theory and provides a unification of the many theoretical models by emphasizing interrelations between seemingly different methodologies. It is not intended as a catalogue of the vast number of plasma instabilities leading to anomalous transport; instead it chooses a number of these and emphasizes the aspects specifically due to turbulence. After a brief introduction, the microscopic theory of turbulence is discussed, including quasilinear theory and various aspects of renormalization methods, which leads to an understanding of resonance broadening, mode coupling, trajectory correlation and clumps. The second half of the book is devoted to stochiastic tramsport, using methods based on the Langevin equations and on Random Walk theory. This treatment aims at going beyond the traditional limits of weak turbulence, by introducing the recently developed method of decorrelation trajectories, and its application to electrostatic turbulence, magnetic turbulence and zonal flow generation. The final chapter includes very recent work on the nonlocal transport phenomenon.

Electostatic Plasma Edge Turbulence and Anomalous Transport in SOL Plasmas

Electostatic Plasma Edge Turbulence and Anomalous Transport in SOL Plasmas PDF Author: Dmitry Meyerson
Publisher:
ISBN:
Category :
Languages : en
Pages : 194

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Book Description
Controlling the scrape-off layer (SOL) properties in order to limit divertor erosion and extend component lifetime will be crucial to successful operation of ITER and devices that follow, where intermittent thermal loads on the order of GW/m2 are expected. Steady state transport in the edge region is generally turbulent with large, order unity, fluctuations and is convection dominated. Owing to the success of the past fifty years of progress in magnetically confining hot plasmas, in this work we examine convective transport phenomena in the SOL that occur in the relatively "slow", drift-ordered fluid limit, most applicable to plasmas near MHD equilibrium. Diamagnetic charge separation in an inhomogeneous magnetic field is the principal energy transfer mechanism powering turbulence and convective transport examined in this work. Two possibilities are explored for controlling SOL conditions. In chapter 2 we review basic physics underlying the equations used to model interchange turbulence in the SOL and use a subset of equations that includes electron temperature and externally applied potential bias to examine the possibility of suppressing interchange driven turbulence in the Texas Helimak. Simulated scans in E0×B0 flow shear, driven by changes in the potential bias on the endplates appears to alter turbulence levels as measured by the mean amplitude of fluctuations. In broad agreement with experiment negative biasing generally decreases the fluctuation amplitude. Interaction between flow shear and interchange instability appears to be important, with the interchange rate forming a natural pivot point for observed shear rates. In chapter 3 we examine the possibility of resonant magnetic perturbations (RMPs) or more generally magnetic field-line chaos to decrease the maximum particle flux incident on the divertor. Naturally occurring error fields as well as RMPs applied for stability control are known to cause magnetic field-line chaos in the SOL region of tokamaks. In chapter 3 2D simulations are used to investigate the effect of the field-line chaos on the SOL and in particular on its width and peak particle flux. The chaos enters the SOL dynamics through the connection length, which is evaluated using a Poincaré map. The variation of experimentally relevant quantities, such as the SOL gradient length scale and the intermittency of the particle flux in the SOL, is described as a function of the strength of the magnetic perturbation. It is found that the effect of the chaos is to broaden the profile of the sheath-loss coefficient, which is proportional to the inverse connection length. That is, the SOL transport in a chaotic field is equivalent to that in a model where the sheathloss coefficient is replaced by its average over the unperturbed flux surfaces. Both fully chaotic and the flux-surface averaged approximation of RMP application significantly lower maximum parallel particle flux incident on the divertor.

On the Edge of Magnetic Fusion Devices

On the Edge of Magnetic Fusion Devices PDF Author: Sergei Krasheninnikov
Publisher: Springer Nature
ISBN: 3030495949
Category : Science
Languages : en
Pages : 269

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Book Description
This book reviews the current state of understanding concerning edge plasma, which bridges hot fusion plasma, with a temperature of roughly one million degrees Kelvin with plasma-facing materials, which have melting points of only a few thousand degrees Kelvin. In a fact, edge plasma is one of the keys to solution for harnessing fusion energy in magnetic fusion devices. The physics governing the processes at work in the edge plasma involves classical and anomalous transport of multispecies plasma, neutral gas dynamics, atomic physics effects, radiation transport, plasma-material interactions, and even the transport of plasma species within the plasma-facing materials. The book starts with simple physical models, then moves on to rigorous theoretical considerations and state-of-the-art simulation tools that are capable of capturing the most important features of the edge plasma phenomena. The authors compare the conclusions arising from the theoretical and computational analysis with the available experimental data. They also discuss the remaining gaps in their models and make projections for phenomena related to edge plasma in magnetic fusion reactors.

Nonlinear Phenomena, Turbulence and Anomalous Transport in Fusion Plasmas

Nonlinear Phenomena, Turbulence and Anomalous Transport in Fusion Plasmas PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 11

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Book Description
The nonlinear nature of the plasma turbulence, as measured by bicoherence analysis, has been studied in stellarator (ATF and W7AS) and tokamak (PBXM) devices. In ATF, little nonlinear interaction is found in the scrape-off layer region whereas the strength of the coupling is enhanced in the edge plasma region where the level of fluctuations is consistent with the theoretical expectations from resistive interchange modes. In W7AS the level of bicoherence is significantly smaller than in ATF. The comparison ATF/W7AS/PBXM suggest the important role of the magnetic shear to determine nonlinear behavior of the turbulence. The level of bicoherence also depends on the plasma conditions: in particular, it increases at the H-mode transition. The comparison between the nonlinear behavior of the turbulence in tokamaks and stellarators allows experimental verification of theoretical turbulence models.

Plasma Instabilities and Anomalous Transport

Plasma Instabilities and Anomalous Transport PDF Author: William B. Pardo
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 376

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Book Description


Turbulence and Anomalous Transport in Magnetized Plasmas: Hints from the Reversed Field Pinch Configuration

Turbulence and Anomalous Transport in Magnetized Plasmas: Hints from the Reversed Field Pinch Configuration PDF Author: V. Antoni
Publisher:
ISBN:
Category :
Languages : en
Pages : 2

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Book Description
Coherent structures are observed to emerge from turbulence background in the edge region of plasmas confined in Reversed Field Pinch configurations. These structures have features reminiscent of single vortices in ordinary fluids and their versus of rotation depends on the local shear of the plasma mean velocity.

Turbulent Transport In Magnetized Plasmas (Second Edition)

Turbulent Transport In Magnetized Plasmas (Second Edition) PDF Author: C Wendell Horton, Jr
Publisher: #N/A
ISBN: 9813225904
Category : Science
Languages : en
Pages : 522

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Book Description
For a few seconds with large machines, scientists and engineers have now created the fusion power of the stars in the laboratory and at the same time find the rich range of complex turbulent electromagnetic waves that transport the plasma confinement systems. The turbulent transport mechanisms created in the laboratory are explained in detail in the second edition of 'Turbulent Transport in Magnetized Plasmas' by Professor Horton.The principles and properties of the major plasma confinement machines are explored with basic physics to the extent currently understood. For the observational laws that are not understood — the empirical confinement laws — offering challenges to the next generation of plasma students and researchers — are explained in detail. An example, is the confinement regime — called the 'I-mode' — currently a hot topic — is explored.Numerous important problems and puzzles for the next generation of plasma scientists are explained. There is growing demand for new simulation codes utilizing the massively parallel computers with MPI and GPU methods. When the 20 billion dollar ITER machine is tested in the 2020ies, new theories and faster/smarter computer simulations running in near real-time control systems will be used to control the burning hydrogen plasmas.

Neoclassical and Anomalous Transport in Axisymmetric Toroidal Plasmas with Electrostatic Turbulence

Neoclassical and Anomalous Transport in Axisymmetric Toroidal Plasmas with Electrostatic Turbulence PDF Author: H. Sugama
Publisher:
ISBN:
Category :
Languages : en
Pages : 50

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Book Description


Turbulence and Anomalous Transport in Magnetized Plasmas

Turbulence and Anomalous Transport in Magnetized Plasmas PDF Author: D. Grésillon
Publisher:
ISBN:
Category :
Languages : en
Pages : 335

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Book Description


Theoretical and Numerical Study of Anomalous Turbulent Transport in Plasmas

Theoretical and Numerical Study of Anomalous Turbulent Transport in Plasmas PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 36

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Book Description
Theoretical and computational analysis of particle transport in a plasma turbulence was carried out. Particle behavior was investigated by test particle simulations in different types of plasma turbulence, including drift wave turbulence, ion acoustic turbulence and Langmuir turbulence. Resonance broadening in real space around mode rational surface was confirmed in drift wave turbulence. Nonresonant interaction of waves and particles were studied in ion acoustic turbulence. Resonance broadening in velocity space was found as a result of non-Markovian process in Langmuir turbulence. A semiclassical quantum plasma approach was also applied to plasma turbulence. Some instabilities in toroidal geometry were studied as eigen value problems.