Download or read book Finite Drift Orbit Effects in a Tokamak Pedestal written by Grigory Alexandrovich Kagan and published by . This book was released on 2009 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis aims at better understanding of the tokamak pedestal, which is a defining feature of the so-called "High Confinement Mode" or "H Mode" of tokamak operation. This region is characterized by a drastic plasma density drop over a relatively short radial distance, typically of order of the poloidal ion gyroradius (p,,). Experiments demonstrate that H Mode plasmas have superior transport properties compared to other known regimes, making them important for practical fusion energy generation. However, the nature of this improvement is still poorly understood and this thesis provides key new insights. According to experiments and simulations, plasmas in a tokamak are turbulent and therefore their physics can only be addressed with a formalism that retains short perpendicular wavelengths such as gyrokinetics. To be applicable in the pedestal, the formalism must also be capable of treating background scales as short as p, and conveniently accounting for the effects of finite ion drift orbits whose size scales with p,, as well. To this end, we develop a special version of gyrokinetics that employs canonical angular momentum in place of the standard radial gyrokinetic variable. Using this formalism to find the leading order ion distribution function we conclude that the background ion temperature profile in the H Mode regime cannot have a steep p,, wide pedestal similar to the one observed for the plasma density. Having obtained this result, we next deduce that a strong electric field is inherently present in a subsonic pedestal to sustain ion pressure balance, making the ExB drift enter the leading order streaming operator in the kinetic equation. We proceed by analyzing novel features that the existence of the pedestal introduces in collisionless zonal flow, the dominant mechanism controlling the anomalous transport. In particular, we find that due to the electric field modifying ion orbits, the zonal flow residual in the pedestal is enhanced over its core value. This allows us to suggest a new scenario for the pedestal formation. Since the turbulence level is lowered, we are led to consider neoclassical mechanisms of plasma transport by retaining collisions in our gyrokinetic equation. Then, we observe that the ExB drift entering the gyrokinetic equation makes the neoclassical ion heat conductivity sensitive to the pedestal electric field. Next, with the help of the same technique we evaluate the neoclassical poloidal ion flow. Importantly, we predict that once the equilibrium electric field goes beyond a certain value this flow changes its direction. This result elucidates the discrepancy between the conventional banana regime predictions and recent experimental measurements of the poloidal impurity flow performed at Alcator C-Mod.
Download or read book Atomic Physics Effects on Tokamak Edge Drift tearing Modes written by Taik Soo Hahm and published by . This book was released on 1993 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1985 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atomic Physics Effects on Tokamak Edge Drift tearing Modes written by and published by . This book was released on 1993 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of ionization and charge exchange on the linear stability of drift-tearing modes are analytically investigated. In particular, the linear instability threshold [Delta]{sup Th}, produced by ion sound wave coupling is modified. In the strongly collisional regime, the ionization breaks up the near cancellation of the perturbed electric field and the pressure gradient along the magnetic field, and increases the threshold. In the semi-collisional regime, both ionization and charge exchange act as drag on the ion parallel velocity, and consequently decrease the threshold by reducing the effectiveness of ion sound wave propagation.
Download or read book INIS Atomindex written by and published by . This book was released on 1996 with total page 730 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1993 with total page 1116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theory of Fusion Plasmas written by Olivier Sauter and published by American Institute of Physics. This book was released on 2008-12-02 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Joint Varenna-Lausanne International Workshop on Theory of Fusion Plasmas takes place every other year in a place particularly favorable for informal and in depth discussions. Invited and contributed papers present state-of-the art researches in theoretical plasma physics, covering all domains relevant to fusion plasmas. This workshop always allows a fruitful mix of experienced researchers and students, to allow for a better understanding of the key theoretical physics models and applications, such as: Theoretical issues related to burning plasmas; Anomalous Transport (Turbulence, Coherent Structures, Microinstabilities) RF Heating and Current Drive; Macroinstabilities; Plasma-Edge Physics and Divertors; Fast particles instabilities.
Download or read book Introduction to Plasma Physics and Controlled Fusion written by Francis F. Chen and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: TO THE SECOND EDITION In the nine years since this book was first written, rapid progress has been made scientifically in nuclear fusion, space physics, and nonlinear plasma theory. At the same time, the energy shortage on the one hand and the exploration of Jupiter and Saturn on the other have increased the national awareness of the important applications of plasma physics to energy production and to the understanding of our space environment. In magnetic confinement fusion, this period has seen the attainment 13 of a Lawson number nTE of 2 x 10 cm -3 sec in the Alcator tokamaks at MIT; neutral-beam heating of the PL T tokamak at Princeton to KTi = 6. 5 keV; increase of average ß to 3%-5% in tokamaks at Oak Ridge and General Atomic; and the stabilization of mirror-confined plasmas at Livermore, together with injection of ion current to near field-reversal conditions in the 2XIIß device. Invention of the tandem mirror has given magnetic confinement a new and exciting dimension. New ideas have emerged, such as the compact torus, surface-field devices, and the EßT mirror-torus hybrid, and some old ideas, such as the stellarator and the reversed-field pinch, have been revived. Radiofrequency heat ing has become a new star with its promise of dc current drive. Perhaps most importantly, great progress has been made in the understanding of the MHD behavior of toroidal plasmas: tearing modes, magnetic Vll Vlll islands, and disruptions.
Download or read book Regular and Chaotic Dynamics written by A.J. Lichtenberg and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book treats nonlinear dynamics in both Hamiltonian and dissipative systems. The emphasis is on the mechanics for generating chaotic motion, methods of calculating the transitions from regular to chaotic motion, and the dynamical and statistical properties of the dynamics when it is chaotic. The new edition brings the subject matter in a rapidly expanding field up to date, and has greatly expanded the treatment of dissipative dynamics to include most important subjects.
Download or read book The Plasma Boundary of Magnetic Fusion Devices written by P.C Stangeby and published by CRC Press. This book was released on 2000-01-01 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Plasma Boundary of Magnetic Fusion Devices introduces the physics of the plasma boundary region, including plasma-surface interactions, with an emphasis on those occurring in magnetically confined fusion plasmas. The book covers plasma-surface interaction, Debye sheaths, sputtering, scrape-off layers, plasma impurities, recycling and control, 1D and 2D fluid and kinetic modeling of particle transport, plasma properties at the edge, diverter and limiter physics, and control of the plasma boundary. Divided into three parts, the book begins with Part 1, an introduction to the plasma boundary. The derivations are heuristic and worked problems help crystallize physical intuition, which is emphasized throughout. Part 2 provides an introduction to methods of modeling the plasma edge region and for interpreting computer code results. Part 3 presents a collection of essays on currently active research hot topics. With an extensive bibliography and index, this book is an invaluable first port-of-call for researchers interested in plasma-surface interactions.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975-06 with total page 1162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ideal MHD written by Jeffrey P. Freidberg and published by Cambridge University Press. This book was released on 2014-06-26 with total page 743 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive, self-contained, and clearly written, this book describes the macroscopic equilibrium and stability of high temperature plasmas.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1993 with total page 1528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fusion Energy Update written by and published by . This book was released on 1978 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Physics written by Alexander Piel and published by Springer. This book was released on 2017-09-07 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: The enlarged new edition of this textbook provides a comprehensive introduction to the basic processes in plasmas and demonstrates that the same fundamental concepts describe cold gas-discharge plasmas, space plasmas, and hot fusion plasmas. Starting from particle drifts in magnetic fields, the principles of magnetic confinement fusion are explained and compared with laser fusion. Collective processes are discussed in terms of plasma waves and instabilities. The concepts of plasma description by magnetohydrodynamics, kinetic theory, and particle simulation are stepwise introduced. Space charge effects in sheath regions, double layers and plasma diodes are given the necessary attention. The novel fundamental mechanisms of dusty plasmas are explored and integrated into the framework of conventional plasmas. The book concludes with a concise description of modern plasma discharges. Written by an internationally renowned researcher in experimental plasma physics, the text keeps the mathematical apparatus simple and emphasizes the underlying concepts. The guidelines of plasma physics are illustrated by a host of practical examples, preferentially from plasma diagnostics. There, Langmuir probe methods, laser interferometry, ionospheric sounding, Faraday rotation, and diagnostics of dusty plasmas are discussed. Though primarily addressing students in plasma physics, the book is easily accessible for researchers in neighboring disciplines, such as space science, astrophysics, material science, applied physics, and electrical engineering. This second edition has been thoroughly revised and contains substantially enlarged chapters on plasma diagnostics, dusty plasmas and plasma discharges. Probe techniques have been rearranged into basic theory and a host of practical examples for probe techniques in dc, rf, and space plasmas. New topics in dusty plasmas, such as plasma crystals, Yukawa balls, phase transitions and attractive forces have been adopted. The chapter on plasma discharges now contains a new section on conventional and high-power impulse magnetron sputtering. The recently discovered electrical asymmetry effect in capacitive rf-discharges is described. The text is based on an introductory course to plasma physics and advanced courses in plasma diagnostics, dusty plasmas, and plasma waves, which the author has taught at Kiel University for three decades. The pedagogical approach combines detailed explanations, a large number of illustrative figures, short summaries of the basics at the end of each chapter, and a selection of problems with detailed solutions.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2018 pages. Available in PDF, EPUB and Kindle. Book excerpt:
