Download or read book Progress in Simulating Turbulent Electron Thermal Transport in NSTX written by and published by . This book was released on 2013 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonlinear simulations based on multiple NSTX discharge scenarios have progressed to help differentiate unique instability mechanisms and to validate with experimental turbulence and transport data. First nonlinear gyrokinetic simulations of microtearing (MT) turbulence in a high-beta NSTX H-mode discharge predict experimental levels of electron thermal transport that are dominated by magnetic flutter and increase with collisionality, roughly consistent with energy confinement times in dimensionless collisionality scaling experiments. Electron temperature gradient (ETG) simulations predict significant electron thermal transport in some low and high beta discharges when ion scales are suppressed by E x B shear. Although the predicted transport in H-modes is insensitive to variation in collisionality (inconsistent with confinement scaling), it is sensitive to variations in other parameters, particularly density gradient stabilization. In reversed shear (RS) Lmode discharges that exhibit electron internal transport barriers, ETG transport has also been shown to be suppressed nonlinearly by strong negative magnetic shear, s“0. In many high beta plasmas, instabilities which exhibit a stiff beta dependence characteristic of kinetic ballooning modes (KBM) are sometimes found in the core region. However, they do not have a distinct finite beta threshold, instead transitioning gradually to a trapped electron mode (TEM) as beta is reduced to zero. Nonlinear simulations of this "hybrid" TEM/KBM predict significant transport in all channels, with substantial contributions from compressional magnetic perturbations. As multiple instabilities are often unstable simultaneously in the same plasma discharge, even on the same flux surface, unique parametric dependencies are discussed which may be useful for distinguishing the different mechanisms experimentally.
Download or read book Final Report of the Committee on a Strategic Plan for U S Burning Plasma Research written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-05-31 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fusion offers the prospect of virtually unlimited energy. The United States and many nations around the world have made enormous progress toward achieving fusion energy. With ITER scheduled to go online within a decade and demonstrate controlled fusion ten years later, now is the right time for the United States to develop plans to benefit from its investment in burning plasma research and take steps to develop fusion electricity for the nation's future energy needs. At the request of the Department of Energy, the National Academies of Sciences, Engineering, and Medicine organized a committee to develop a strategic plan for U.S. fusion research. The final report's two main recommendations are: (1) The United States should remain an ITER partner as the most cost-effective way to gain experience with a burning plasma at the scale of a power plant. (2) The United States should start a national program of accompanying research and technology leading to the construction of a compact pilot plant that produces electricity from fusion at the lowest possible capital cost.
Download or read book Simulation Of Microtearing Turbulence In NSTX written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal energy confinement times in NSTX dimensionless parameter scans increase with decreasing collisionality. While ion thermal transport is neoclassical, the source of anomalous electron thermal transport in these discharges remains unclear, leading to considerable uncertainty when extrapolating to future ST devices at much lower collisionality. Linear gyrokinetic simulations find microtearing modes to be unstable in high collisionality discharges. First non-linear gyrokinetic simulations of microtearing turbulence in NSTX show they can yield experimental levels of transport. Magnetic flutter is responsible for almost all the transport (≈98%), perturbed field line trajectories are globally stochastic, and a test particle stochastic transport model agrees to within 25% of the simulated transport. Most significantly, microtearing transport is predicted to increase with electron collisionality, consistent with the observed NSTX confinement scaling. While this suggests microtearing modes may be the source of electron thermal transport, the predictions are also very sensitive to electron temperature gradient, indicating the scaling of the instability threshold is important. In addition, microtearing turbulence is susceptible to suppression via sheared E-B flows as experimental values of E-B shear (comparable to the linear growth rates) dramatically reduce the transport below experimental values. Refinements in numerical resolution and physics model assumptions are expected to minimize the apparent discrepancy. In cases where the predicted transport is strong, calculations suggest that a proposed polarimetry diagnostic may be sensitive to the magnetic perturbations associated with the unique structure of microtearing turbulence.
Download or read book Nonlinear Turbulence Simulations for NSTX H modes written by M. H. Redi and published by . This book was released on 2004 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stabilization of Electron scale Turbulence by Electron Density Gradient in NSTX written by and published by . This book was released on 2015 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microturbulence is present in all magnetic confinement fusion devices, and is believed to play a major role in driving anomalous transport levels that exceed neoclassical theory predictions. In NSTX, electron thermal transport is found to dominate energy loss. Theory and experiments have shown that electron temperature gradient (ETG) turbulence on the electron gyro-scale, kl̲pe
Download or read book Annual Highlights written by Princeton University. Plasma Physics Laboratory and published by . This book was released on 2006 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fusion Physics written by MITSURU KIKUCHI and published by International Atomic Energy. This book was released on 2002-01-01 with total page 1158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Humans do not live by bread alone. Physically we are puny creatures with limited prowess, but with unlimited dreams. We see a mountain and want to move it to carve out a path for ourselves. We see a river and want to tame it so that it irrigates our fields. We see a star and want to fly to its planets to secure a future for our progeny. For all this, we need a genie who will do our bidding at a flip of our fingers. Energy is such a genie. Modern humans need energy and lots of it to live a life of comfort. In fact, the quality of life in different regions of the world can be directly correlated with the per capita use of energy [1.1–1.5]. In this regard, the human development index (HDI) of various countries based on various reports by the United Nations Development Programme (UNDP) [1.6] (Fig. 1.1), which is a parameter measuring the quality of life in a given part of the world, is directly determined by the amount of per capita electricity consumption. Most of the developing world (~5 billion people) is crawling up the UN curve of HDI versus per capita electricity consumption, from abysmally low values of today towards the average of the whole world and eventually towards the average of the developed world. This translates into a massive energy hunger for the globe as a whole. It has been estimated that by the year 2050, the global electricity demand will go up by a factor of up to 3 in a high growth scenario [1.7–1.9]. The requirements beyond 2050 go up even higher.
Download or read book Fusion Nucl aire written by and published by . This book was released on 2006-05 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Systems Approaches to Nuclear Fusion Reactors written by Frederick B. Marcus and published by Springer Nature. This book was released on 2023-01-01 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers an overall review, applying systems engineering and architecture approaches, of the design, optimization, operation and results of leading fusion experiments. These approaches provide a unified means of evaluating reactor design. Methodologies are developed for more coherent construction or evaluation of fusion devices, associated experiments and operating procedures. The main focus is on tokamaks, with almost all machines and their important results being integrated into a systems design space. Case studies focus on DIII-D, TCV, JET, WEST, the fusion reactor prototype ITER and the EU DEMO concept. Stellarator, Mirror and Laser inertial confinement experiments are similarly analysed, including reactor implications of breakeven at NIF. The book examines the engineering and physics design and optimization process for each machine, analysing their performance and major results achieved, thus establishing a basis for the improvement of future machines. The reader will gain a broad historical and up-to-date perspective of the status of nuclear fusion research from both an engineering and physics point of view. Explanations are given of the computational tools needed to design and operate successful experiments and reactor-relevant machines. This book is aimed at both graduate students and practitioners of nuclear fusion science and engineering, as well as those specializing in other fields demanding large and integrated experimental equipment. Systems engineers will obtain valuable insights into fusion applications. References are given to associated complex mathematical derivations, which are beyond the scope of this book. The general reader interested in nuclear fusion will find here an accessible summary of the current state of nuclear fusion.
Download or read book Energy and Water Development Appropriations for 2011 Part 3 February 2010 111 2 Hearings written by and published by . This book was released on 2010 with total page 1284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tokamak Start Up Problems and Scenarios Related to the Transient Phases of a Thermonuclear Fusion Reactor Ettor Majorana International Science Series written by Heinz Knoepfel and published by Springer. This book was released on 2013-12-19 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Energy and Water Development Appropriations for 2011 Dept of Energy fiscal year 2011 justifications cont written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2010 with total page 1284 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 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 Interstellar Turbulence written by José Franco and published by Cambridge University Press. This book was released on 1999-05-28 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: This timely volume presents a series of review articles covering every aspect of interstellar turbulence--from accretion disks, molecular clouds, atomic and ionized media, through to spiral galaxies - based on a major international conference held in Mexico City.With advances in observational techniques and the development of more efficient computer codes and faster computers, research in this area has made spectacular progress in recent years. This book provides a comprehensive overview of the most important developments in observing and modelling turbulent flows in the cosmos. It provides graduate student and researchers with a state-of-the-art summary of observational, theoretical and computational research in interstellar turbulence.
Download or read book Energy and Water Development Appropriations for 2012 Dept of Energy FY 2012 justifications cont written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2011 with total page 1092 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
