Measured and Simulated Election Thermal Transport in the Madison Symmetric Torus Reversed Field Pinch PDF Download

Author: Joshua Adam Reusch
Publisher:
ISBN:
Category :
Languages : en
Pages : 222

View

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 18

View

Book Description
Studies of large-size (R = 1.5 m, a = 0.5 m), moderate current (I

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
Introduces the Madison Symmetric Torus (MST), a toroidal reversed field pinch device for the study of plasma physics and magnetic fusion energy research operating out of the Department of Physics at the University of Wisconsin-Madison. Describes the MST as a large RFP reversed field pinch with a minor radius of 0.52 m and a major radius of 1.5 m. Includes specifications of device and plasma parameters, answers to frequently asked questions, information for prospective graduate students, and related programs at UW-M. Lists senior staff of the Physics Department.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 159

View

Book Description
The work presented in this thesis is concerned with addressing the nature of drift wave microturbulence in the reversed field pinch (RFP). Microturbulence is an important phenomenon and contributor to heat and particle transport in tokamaks, where it has been studied for several decades, but its role in the RFP is a rather new topic of study. As such, the nature of RFP drift waves and their relationship to their tokamak counterparts is still developing, and many of the results in this work are focused on addressing this challenge. Fundamental advances in microturbulence research have been made in recent decades through two parallel developments: the theoretical framework encompassed in the gyrokinetic model, and the computational power offered by massively-parallel, high-performance computing systems. Gyrokinetics is a formulation of kinetic theory in such a way that the fast timescale gyromotion of particles around magnetic field lines is averaged out. The implementation and use of RFP equilibrium models in gyrokinetic codes constitutes the bulk of this thesis. A simplified analytic equilibrium, the toroidal Bessel function model (TBFM), is used in the gyrokinetic code GYRO to explore the fundamental scaling properties of drift waves in the RFP geometry. Two drift wave instabilities, the ion temperature gradient (ITG) mode and the microtearing mode (MTM) are found to occur, and the relationship of their critical threshold in driving gradients and plasma beta is explored. The critical values in these parameters are found to be above those of similar tokamak cases by roughly a factor of the flux surface aspect ratio. The MTM is found to be stabilized by increasing the RFP pinch parameter theta, making it unlikely for it to unstable in the high-theta improved confinement pulsed poloidal current drive (PPCD) discharges. Efforts are also made to address microinstabilities in specific experimental discharges of the Madison Symmetric Torus (MST). A semi-analytic equilibrium, the adjusted circular model (ACM), is developed and implemented in the gyrokinetic code GENE to investigate representative PPCD discharges. The flexibility of the ACM enables it to be used for the high-theta PPCD discharges where the TBFM breaks down. The dominant linear instabilites for the discharges modeled here -- ITG and the trapped electron mode (TEM) -- are studied, as are their scaling properties in the PPCD regime. It is found that these instabilities are present outside of the reversal surface, where the driving gradients are strongest. Nonlinear simulations of the TEM turbulence are performed, the first such done for the RFP, and zonal flows are found to play an important role in the nonlinear saturation mechanism. These zonal flows lead to a large Dimits-like shift and suppressed transport. There is also evidence that residual global tearing mode fluctuations are a necessary part of modeling transport in the RFP, even in improved confinement PPCD discharges, and by modeling these residual fluctuations through the use of an externally imposed perpendicular magnetic field perturbation it is possible to bring simulated fluxes into agreement with experiment. Finally, the nature of the collisionless MTM, an instability seen to arise in some parameter regimes of the RFP, is investigated analytically using a fluid expansion in the drift-kinetic framework. Particular attention is paid to the role of magnetic drifts, and some evidence for their role in the collisionless instability is presented. Comparisons are made to gyrokinetic simulations and to earlier theory on the magnetic-curvature drift instability.

Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1102

View

Book Description

Author: Kenro Miyamoto
Publisher: Taylor & Francis
ISBN: 1584887109
Category : Science
Languages : en
Pages : 393

View

Book Description
Resulting from ongoing, international research into fusion processes, the International Tokamak Experimental Reactor (ITER) is a major step in the quest for a new energy source.The first graduate-level text to cover the details of ITER, Controlled Fusion and Plasma Physics introduces various aspects and issues of recent fusion research activ

Author: Olof Hallonsten
Publisher: Springer
ISBN: 3319327380
Category : Social Science
Languages : en
Pages : 310

View

Book Description
This book analyses the emergence of a transformed Big Science in Europe and the United States, using both historical and sociological perspectives. It shows how technology-intensive natural sciences grew to a prominent position in Western societies during the post-World War II era, and how their development cohered with both technological and social developments. At the helm of post-war science are large-scale projects, primarily in physics, which receive substantial funds from the public purse. Big Science Transformed shows how these projects, popularly called 'Big Science', have become symbols of progress. It analyses changes to the political and sociological frameworks surrounding publicly-funding science, and their impact on a number of new accelerator and reactor-based facilities that have come to prominence in materials science and the life sciences. Interdisciplinary in scope, this book will be of great interest to historians, sociologists and philosophers of science.

Author: Sergei S. Molokov
Publisher: Springer Science & Business Media
ISBN: 1402048335
Category : Science
Languages : en
Pages : 408

View

Book Description
This book revises the evolution of ideas in various branches of magnetohydrodynamics (astrophysics, earth and solar dynamos, pinch, MHD turbulence and liquid metals) and reviews current trends and challenges. Uniquely, it contains the review articles on the development of the subject by pioneers in the field as well as leading experts, not just in one, but in various branches of magnetohydrodynamics, such as liquid metals, astrophysics, dynamo and pinch.

Author: Heinz Knoepfel
Publisher: Springer
ISBN: 1475718896
Category : Technology & Engineering
Languages : en
Pages : 425

View

Book Description
This book contains the papers presented at the Course on "Tokamak Startup - Problems and Scenarios Related to the Transient Phases of a Thermonuclear Fusion Reactor" which was held in Erice, July 14-20, 1985. The fact that the critical startup and transient phases of a tokamak reactor are now the specific subject of a comprehensive international gathering of fusion specialists seems indicative of the substantial pro gress made in recent years towards attaining controlled ignition of a nuclear fusion fuel, i.e. towards demonstrating the scientific feasibili ty of controlled thermonuclear fusion. In fact, the steady-state burning phase has attracted so far most of the attention of fusion physicists and engineers, as it is conceptually more rewarding, and theoretically easier to handle. However, as for many large engineering systems, - nuclear fis- ... ':1' " . 10 ' ... Entrance to San Rocco's lecturing hall v sion power plants, or aerospace crafts, for example - the major issues of design and operation lie often in the startup, shutdown and power tran sieQt phases, rather than at the full load, or at cruising regimes. In ehoosing the contributions to this 7th Course of Prof. B.

Author: Kenrō Miyamoto
Publisher:
ISBN: 9784900491113
Category : Controlled fusion
Languages : en
Pages : 401

View

Book Description