Author: A. M. M. ToddPublisher:
ISBN:
Category :
Languages : en
Pages : 38
Book Description
Dependence of Ideal MHD Kink and Ballooning Modes on Plasma Shape and Profiles in Tokamaks
Author: A. M. M. ToddDependence of Ideal MHD Kink and Ballooning Modes on Plasma Shape and Profiles in Tokamaka
Author: Princeton University. Plasma Physics LaboratoryPublisher:
ISBN:
Category : Magnetohydrodynamics
Languages : en
Pages : 38
Book Description
Dependence of Ideal MHD Kink and Ballooning Modes on Plasma Shape and Profiles in Tokamaks
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Extensive numerical studies of ideal MHD instabilities have been carried out to gain insight into the parametric dependence of critical .beta.'s in tokamaks. The large number of interrelated equilibrium quantities involved in establishing a critical .beta. has demanded a careful, systematic survey in order to isolate this dependence. The results of this survey establish the scaling with geometrical quantities including aspect ratio, elongation, and triangularity in the parameter regimes appropriate for both current and reactor-sized plasmas. A moderate dependence on the pressure profile and a strong variation with the current profile is found. The principal result is that for aspect ratio R/a approximately equal to 3, critical .beta.'s are of the order of 2% for circular cross sections and 5% for plasmas with elongation K approximately equal to 2; somewhat higher values could be achieved with more optimal shaping. Finally, sequences of equilibria have been analyzed to compare critical .beta. as a function of toroidal mode number n. We conclude that the infinite-n analytic ballooning theory provides a sufficient condition for ideal MHD internal mode stability. Low-n free boundary modes appear to set a lower limit.
Fusion Energy Update
Author: Energy Research Abstracts
Author: Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 806
Book Description
Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.
Finite Element Methods in Linear Ideal Magnetohydrodynamics
Author: Ralf GruberPublisher: Springer Science & Business Media
ISBN: 3642867081
Category : Science
Languages : en
Pages : 190
Book Description
For more than ten years we have been working with the ideal linear MHD equations used to study the stability of thermonuc1ear plasmas. Even though the equations are simple and the problem is mathematically well formulated, the numerical problems were much harder to solve than anticipated. Already in the one-dimensional cylindrical case, what we called "spectral pollution" appeared. We were able to eliminate it by our "ecological solution". This solution was applied to the two-dimensional axisymmetric toroidal geometry. Even though the spectrum was unpolluted the precision was not good enough. Too many mesh points were necessary to obtain the demanded precision. Our solution was what we called the "finite hybrid elements". These elements are efficient and cheap. They have also proved their power when applied to calculating equilibrium solutions and will certainly penetrate into other domains in physics and engineering. During all these years, many colleagues have contributed to the construc tion, testing and using of our stability code ERATO. We would like to thank them here. Some ofthem gave partial contributions to the book. Among them we mention Dr. Kurt Appert, Marie-Christine Festeau-Barrioz, Roberto Iacono, Marie-Alix Secretan, Sandro Semenzato, Dr. Jan Vac1avik, Laurent Villard and Peter Merkel who kindly agreed to write Chap. 6. Special thanks go to Hans Saurenmann who drew most of the figures, to Dr
Magnetohydrodynamic Stability of Tokamaks
Author: Hartmut ZohmPublisher: John Wiley & Sons
ISBN: 3527412328
Category : Science
Languages : en
Pages : 254
Book Description
This book bridges the gap between general plasma physics lectures and the real world problems in MHD stability. In order to support the understanding of concepts and their implication, it refers to real world problems such as toroidal mode coupling or nonlinear evolution in a conceptual and phenomenological approach. Detailed mathematical treatment will involve classical linear stability analysis and an outline of more recent concepts such as the ballooning formalism. The book is based on lectures that the author has given to Master and PhD students in Fusion Plasma Physics. Due its strong link to experimental results in MHD instabilities, the book is also of use to senior researchers in the field, i.e. experimental physicists and engineers in fusion reactor science. The volume is organized in three parts. It starts with an introduction to the MHD equations, a section on toroidal equilibrium (tokamak and stellarator), and on linear stability analysis. Starting from there, the ideal MHD stability of the tokamak configuration will be treated in the second part which is subdivided into current driven and pressure driven MHD. This includes many examples with reference to experimental results for important MHD instabilities such as kinks and their transformation to RWMs, infernal modes, peeling modes, ballooning modes and their relation to ELMs. Finally the coverage is completed by a chapter on resistive stability explaining reconnection and island formation. Again, examples from recent tokamak MHD such as sawteeth, CTMs, NTMs and their relation to disruptions are extensively discussed.
Pseudo-MHD Ballooning Modes in Tokamak Plasmas
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The MHD description of a plasma is extended to allow electrons to have both fluid-like and adiabatic-regime responses within an instability eigenmode. In the resultant[open-quotes]pseudo-MHD[close-quotes] model, magnetic field line bending is reduced in the adiabatic electron regime. This makes possible a new class of ballooning-type, long parallel extent, MHD-like instabilities in tokamak plasmas for[alpha]> s[sup 2](2[sup 7/3]/9) (r[sub p]/R[sub 0]) or-d[radical][Beta]/dr> (2[sup 1/6] /3)(s/ R[sub 0q]), which is well below the ideal-MHD stability boundary. The marginally stable pressure profile is similar in both magnitude and shape to that observed in ohmically heated tokamak plasmas.
Ideal MHD Stability of Very High Beta Tokamaks
Author: M. S. ChanceMonthly Catalog of United States Government Publications
Author: Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1064
Book Description