INTERPRETIVE MODELING OF SIMPLE-AS-POSSIBLE-PLASMA DISCHARGES ON DIII-D USING THE OEDGE CODE.

INTERPRETIVE MODELING OF SIMPLE-AS-POSSIBLE-PLASMA DISCHARGES ON DIII-D USING THE OEDGE CODE. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 14

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Book Description
Recently a number of major, unanticipated effects have been reported in tokamak edge research raising the question of whether we understand the controlling physics of the edge. This report is on the first part--here focused on the outer divertor--of a systematic study of the simplest possible edge plasma--no ELMs, no detachment, etc.--for a set of 10 repeat, highly-diagnosed, single-null, divertor discharges in DIII-D. For almost the entire, extensive data set so far evaluated, the matches of experiment and model are so close as to imply that the controlling processes at the outer divertor for these simple plasma conditions have probably been correctly identified and quantitatively characterized in the model. The principal anomaly flagged so far relates to measurements of T{sub e} near the target, potentially pointing to a deficiency in our understanding of sheath physics in the tokamak environment.

INTERPRETIVE MODELING OF SIMPLE-AS-POSSIBLE-PLASMA DISCHARGES ON DIII-D USING THE OEDGE CODE.

INTERPRETIVE MODELING OF SIMPLE-AS-POSSIBLE-PLASMA DISCHARGES ON DIII-D USING THE OEDGE CODE. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 14

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Book Description
Recently a number of major, unanticipated effects have been reported in tokamak edge research raising the question of whether we understand the controlling physics of the edge. This report is on the first part--here focused on the outer divertor--of a systematic study of the simplest possible edge plasma--no ELMs, no detachment, etc.--for a set of 10 repeat, highly-diagnosed, single-null, divertor discharges in DIII-D. For almost the entire, extensive data set so far evaluated, the matches of experiment and model are so close as to imply that the controlling processes at the outer divertor for these simple plasma conditions have probably been correctly identified and quantitatively characterized in the model. The principal anomaly flagged so far relates to measurements of T{sub e} near the target, potentially pointing to a deficiency in our understanding of sheath physics in the tokamak environment.

Toroidally Symmetric Methane Injection Into the Main Scrape-off Layer of DIII-D

Toroidally Symmetric Methane Injection Into the Main Scrape-off Layer of DIII-D PDF Author: John David Elder
Publisher:
ISBN: 9780494393710
Category : Aerospace engineering
Languages : en
Pages : 155

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Book Description
In 2003 and 2005 13CH4 puffing experiments were conducted on DIII-D [1] in L and ELMy H mode plasmas respectively. The motivation for these experiments was to develop a greater understanding of impurity creation, transport and deposition for hydrocarbons which are produced at the walls of DIII-D by chemical sputtering. In both experiments, tiles from around the vessel were removed after the experiment was complete and the distribution of the 13C deposition was measured using nuclear reaction analysis. During each of these experiments the plasma conditions and emissions were monitored by a number of direct and spectroscopic diagnostics including Langmuir probes, Thomson scattering, the multichord divertor spectrometer, filterscopes, reciprocating probes and others. These diagnostic measurements are used in the thesis to develop a background plasma solution for the experiments through the procedure of empirical plasma reconstruction. These background plasma solutions are used as the basis for modeling the emissions, transport and deposition of the 13C resulting from the breakup of 13CH4 using the OEDGE code. OEDGE was enhanced by the addition of improved methane breakup kinetics models, improved peripheral particle transport, improved support for line profile modeling as well as many other features. The modeling successfully reproduces most of the spectroscopic measurements as well as the observed 13C deposition patterns in both distribution and magnitude. In order to match the experimental results, fast parallel transport in the SOL had to be imposed on the carbon ions. In addition, a radial pinch was required in the SOL for both the L and H mode experiments to move the carbon closer to the separatrix so that it could deposit where it was measured experimentally. Without both of these flows the simulations were unable to replicate the experimental observations. The effects of radial variation in the parallel flow and erosion of deposited 13C were also both investigated. It was found that neither of these processes by itself appears to be capable of replicating the experimental results.

Fusion Science and Technology

Fusion Science and Technology PDF Author:
Publisher:
ISBN:
Category : Fusion reactors
Languages : en
Pages : 808

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Book Description


Energy Research Abstracts

Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 972

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Book Description


The Plasma Boundary of Magnetic Fusion Devices

The Plasma Boundary of Magnetic Fusion Devices PDF Author: P.C Stangeby
Publisher: CRC Press
ISBN: 9780750305594
Category : Science
Languages : en
Pages : 738

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Book Description
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.

Sputtering by Particle Bombardment

Sputtering by Particle Bombardment PDF Author: Rainer Behrisch
Publisher: Springer Science & Business Media
ISBN: 3540445021
Category : Technology & Engineering
Languages : en
Pages : 527

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Book Description
This book provides a long-needed survey of new results. Especially welcome is a new summary of the measured and calculated sputtering yields with an algebraic approximation formula for the energy and angular dependence of the yields, which is useful for researchers who need sputtering yields for physics research or applied problems. The book offers a critical review of computational methods for calculating sputtering yields and also includes molecular dynamics calculations.

Fusion energy program

Fusion energy program PDF Author: United States. Congress. House. Committee on Science, Space, and Technology. Subcommittee on Investigations and Oversight
Publisher:
ISBN:
Category :
Languages : en
Pages : 826

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Book Description


Fusion Plasma Physics

Fusion Plasma Physics PDF Author: Weston M. Stacey
Publisher: John Wiley & Sons
ISBN: 3527411348
Category : Science
Languages : en
Pages : 674

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Book Description
This revised and enlarged second edition of the popular textbook and reference contains comprehensive treatments of both the established foundations of magnetic fusion plasma physics and of the newly developing areas of active research. It concludes with a look ahead to fusion power reactors of the future. The well-established topics of fusion plasma physics -- basic plasma phenomena, Coulomb scattering, drifts of charged particles in magnetic and electric fields, plasma confinement by magnetic fields, kinetic and fluid collective plasma theories, plasma equilibria and flux surface geometry, plasma waves and instabilities, classical and neoclassical transport, plasma-materials interactions, radiation, etc. -- are fully developed from first principles through to the computational models employed in modern plasma physics. The new and emerging topics of fusion plasma physics research -- fluctuation-driven plasma transport and gyrokinetic/gyrofluid computational methodology, the physics of the divertor, neutral atom recycling and transport, impurity ion transport, the physics of the plasma edge (diffusive and non-diffusive transport, MARFEs, ELMs, the L-H transition, thermal-radiative instabilities, shear suppression of transport, velocity spin-up), etc. -- are comprehensively developed and related to the experimental evidence. Operational limits on the performance of future fusion reactors are developed from plasma physics and engineering constraints, and conceptual designs of future fusion power reactors are discussed.

Fusion Nucléaire

Fusion Nucléaire PDF Author:
Publisher:
ISBN:
Category : Electronic journals
Languages : en
Pages : 562

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Book Description


Iter Physics

Iter Physics PDF Author: C Wendell Horton, Jr
Publisher: World Scientific
ISBN: 9814678686
Category : Science
Languages : en
Pages : 248

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Book Description
The promise of a vast and clean source of thermal power drove physics research for over fifty years and has finally come to collimation with the international consortium led by the European Union and Japan, with an agreement from seven countries to build a definitive test of fusion power in ITER. It happened because scientists since the Manhattan project have envisioned controlled nuclear fusion in obtaining energy with no carbon dioxide emissions and no toxic nuclear waste products.This large toroidal magnetic confinement ITER machine is described from confinement process to advanced physics of plasma-wall interactions, where pulses erupt from core plasma blistering the machine walls. Emissions from the walls reduce the core temperature which must remain ten times hotter than the 15 million degree core solar temperature to maintain ITER fusion power. The huge temperature gradient from core to wall that drives intense plasma turbulence is described in detail.Also explained are the methods designed to limit the growth of small magnetic islands, the growth of edge localized plasma plumes and the solid state physics limits of the stainless steel walls of the confinement vessel from the burning plasma. Designs of the wall coatings and the special 'exhaust pipe' for spent hot plasma are provided in two chapters. And the issues associated with high-energy neutrons — about 10 times higher than in fission reactions — and how they are managed in ITER, are detailed.