Share

Anomalous Transport Modelling of Tokamak Plasmas

1992
Download Anomalous Transport Modelling of Tokamak Plasmas PDF Online Free

Author :
Release : 1992
Genre :
Kind : eBook
Book Rating : /5 ( reviews)

GET EBOOK


Book Synopsis Anomalous Transport Modelling of Tokamak Plasmas by :

Download or read book Anomalous Transport Modelling of Tokamak Plasmas written by . This book was released on 1992. Available in PDF, EPUB and Kindle. Book excerpt: Theory based transport simulations of DIII-D, JET, ITER are compared to experimental data using a combination of anamolous transport models. The Multiple-mode Transport Model is calibrated to a give set of L-mode and H-mode discharges with an emphasis on testing the adequacy of anomalous flux contributions from drift/[eta][sub i] and resistive ballooning mode theories. A survey of possible additions and/or alternatives to the model from recent theories on neoclassical MHD effects, hot ion modes, circulating electron modes, and high-m tearing modes is also included.

Aspects of Anomalous Transport in Plasmas

2005-04-01 Science
Download Aspects of Anomalous Transport in Plasmas PDF Online Free

Author :
Release : 2005-04-01
Genre : Science
Kind : eBook
Book Rating : 684/5 ( reviews)

GET EBOOK


Book Synopsis Aspects of Anomalous Transport in Plasmas by : Radu Balescu

Download or read book Aspects of Anomalous Transport in Plasmas written by Radu Balescu. This book was released on 2005-04-01. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Integrated Model for Transport and Large Scale Instabilities in Tokamak Plasmas

2009
Download Integrated Model for Transport and Large Scale Instabilities in Tokamak Plasmas PDF Online Free

Author :
Release : 2009
Genre :
Kind : eBook
Book Rating : 835/5 ( reviews)

GET EBOOK


Book Synopsis Integrated Model for Transport and Large Scale Instabilities in Tokamak Plasmas by : Federico David Halpern

Download or read book Integrated Model for Transport and Large Scale Instabilities in Tokamak Plasmas written by Federico David Halpern. This book was released on 2009. Available in PDF, EPUB and Kindle. Book excerpt: Improved models for neoclassical tearing modes and anomalous transport are developed and validated within integrated modeling codes to predict toroidal rotation, temperature and current density profiles in tokamak plasmas. Neoclassical tearing modes produce helical filaments of plasma, called magnetic islands, which have the effect of degrading tokamak plasma confinement or terminating the discharge. An improved code is developed in order to compute the widths of multiple simultaneous magnetic islands whose shapes are distorted by the radial variation in the magnetic perturbation [F. D. Halpern, et al., J. Plasma Physics 72 (2006) 1153]. It is found in simulations of DIII-D and JET tokamak discharges that multiple simultaneous magnetic islands produce a 10% to 20% reduction in plasma thermal confinement. If magnetic islands are allowed to grow to their full width in ITER fusion reactor simulations, fusion power production is reduced by a factor of four [F. D. Halpern, et al., Phys. Plasmas 13 (2006) 062510]. In addition to improving the prediction of neoclassical tearing modes, a new Multi-Mode transport model, MMM08, was developed to predict temperature and toroidal angular frequency profiles in simulations of tokamak discharges. The capability for predicting toroidal rotation is motivated by ITER simulation results that indicate that the effects of toroidal rotation can increase ITER fusion power production [F. D. Halpern et al., Phys. Plasmas 15 (2008), 062505]. The MMM08 model consists of an improved model for transport driven by ion drift modes [F. D. Halpern et al., Phys. Plasmas 15 (2008) 012304] together with a model for transport driven by short wavelength electron drift modes combined with models for transport driven by classical processes. The new MMM08 transport model was validated by comparing predictive simulation results with experimental data for 32 discharges in the DIII-D and JET tokamaks. It was found that the prediction of intrinsic plasma rotation is consistent with experimental measurements in discharges with zero net torque. A scaling relation was developed for the toroidal momentum confinement time (angular momentum divided by net torque) as a function of plasma current and torque per ion.

Transport Analysis in Tokamak Plasmas

2010-08
Download Transport Analysis in Tokamak Plasmas PDF Online Free

Author :
Release : 2010-08
Genre :
Kind : eBook
Book Rating : 566/5 ( reviews)

GET EBOOK


Book Synopsis Transport Analysis in Tokamak Plasmas by : Sara Moradi

Download or read book Transport Analysis in Tokamak Plasmas written by Sara Moradi. This book was released on 2010-08. Available in PDF, EPUB and Kindle. Book excerpt: One of the least understood areas of the plasma particle or heat transport is the turbulent transport. In this work the main focus is on the development and data analysis of anomalous transport characteristics (transport coefficients and fluxes) under fusion conditions in large tokamaks. Fluid and gyro-kinetic models are used and obtained results are compared. A model based on fractional kinetics for the study of the SOL turbulent transport characteristics, where non-Gaussian PDFs are observed, is developed.

Pressure-driven Transport in the Core of Tokamak Plasmas

1998 Plasma instabilities
Download Pressure-driven Transport in the Core of Tokamak Plasmas PDF Online Free

Author :
Release : 1998
Genre : Plasma instabilities
Kind : eBook
Book Rating : /5 ( reviews)

GET EBOOK


Book Synopsis Pressure-driven Transport in the Core of Tokamak Plasmas by : Aaron John Redd

Download or read book Pressure-driven Transport in the Core of Tokamak Plasmas written by Aaron John Redd. This book was released on 1998. Available in PDF, EPUB and Kindle. Book excerpt: There is experimental and theoretical evidence of anomalous transport near the magnetic axis in tokamak plasmas, a region in which drift modes are linearly stable. Experimental evidence suggests that this additional transport is strongly affected by the plasma geometry (i.e., elongation and triangularity), more so than drift modes[1]. The finite-beta kinetic ballooning instability is predicted to exist close to the magnetic axis and is strongly affected by the plasma geometry. In this study, we explore the properties of the kinetic ballooning mode with the comprehensive electromagnetic kinetic stability calculations of the FULL code. Using FULL, we quantify the parametric dependence of kinetic ballooning transport on various plasma parameters, including the flux-surface elongation and triangularity, the normalized pressure beta and the flux-surface inverse aspect ratio. Based on these stability calculations, an algebraic kinetic ballooning transport model is developed. Also included in this dissertation are two independent studies of transport in tokamak plasmas, carried out with the BALDUR predictive transport code. In the first study, the sensitivity of these transport simulations to boundary and initial conditions is examined. In the second, a transport model developed by Ottaviani, Horton and Erba (OHE) is incorporated into the BALDUR code, and the density and temperature profiles predicted by this model are compared to experiment for a series of experimental discharges.

You may also like...