Recent Results from the DIII-D Tokamak and Implications for Future Devices

Recent Results from the DIII-D Tokamak and Implications for Future Devices PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 31

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Book Description
Improvements to the DIII-D tokamak have led to significant new research results and enhanced performance. These results provide important inputs to the design of next generation divertor systems including the upgrade of the DIII-D divertor. The use of graphite for the plasma facing components and careful wall preparation has enabled the routine achievement of regimes of enhanced energy confinement. In elongated discharges, triangularity has been found to be important in attaining good discharge performance as measured by the product of the normalized plasma pressure and the energy confinement time, [beta][tau]{sub E} This constrains the design of the divertor configuration (X-point location). Active pumping of the divertor region using an in-situ toroidal cryogenic pump has demonstrated control of the plasma density in H-mode discharges and allowed the dependence of confinement on plasma density and current to be separately determined. Helium removal from the plasma edge sufficient to achieve effective ash removal in reactor discharges has also been demonstrated using this pumping configuration. The reduction of the heat flux to the divertor plates has been demonstrated using two different techniques to increase the radiation in the boundary regions of the plasma and thus reduce the heat flux to the divertor plates; deuterium gas injection has been used to create a strongly radiating localized zone near the X-point, and impurity (neon) injection to enhance the radiation from the plasma mantle. Precise shaping of the plasma current profile has been found to be important in achieving enhanced tokamak performance. Transiently shaped current profiles have been used to demonstrate regimes of plasmas with high beta and good confinement. Control of the current profile also is important to sustaining the plasma in the Very High (VH)-mode of energy confinement.

Recent Results from the DIII-D Tokamak and Implications for Future Devices

Recent Results from the DIII-D Tokamak and Implications for Future Devices PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 31

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Book Description
Improvements to the DIII-D tokamak have led to significant new research results and enhanced performance. These results provide important inputs to the design of next generation divertor systems including the upgrade of the DIII-D divertor. The use of graphite for the plasma facing components and careful wall preparation has enabled the routine achievement of regimes of enhanced energy confinement. In elongated discharges, triangularity has been found to be important in attaining good discharge performance as measured by the product of the normalized plasma pressure and the energy confinement time, [beta][tau]{sub E} This constrains the design of the divertor configuration (X-point location). Active pumping of the divertor region using an in-situ toroidal cryogenic pump has demonstrated control of the plasma density in H-mode discharges and allowed the dependence of confinement on plasma density and current to be separately determined. Helium removal from the plasma edge sufficient to achieve effective ash removal in reactor discharges has also been demonstrated using this pumping configuration. The reduction of the heat flux to the divertor plates has been demonstrated using two different techniques to increase the radiation in the boundary regions of the plasma and thus reduce the heat flux to the divertor plates; deuterium gas injection has been used to create a strongly radiating localized zone near the X-point, and impurity (neon) injection to enhance the radiation from the plasma mantle. Precise shaping of the plasma current profile has been found to be important in achieving enhanced tokamak performance. Transiently shaped current profiles have been used to demonstrate regimes of plasmas with high beta and good confinement. Control of the current profile also is important to sustaining the plasma in the Very High (VH)-mode of energy confinement.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 380

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Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Recent Results from DIII-D and Their Implications for Next Generation Tokamaks

Recent Results from DIII-D and Their Implications for Next Generation Tokamaks PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 20

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Book Description
Recent results from the DIII-D tokamak have provided significant contributions to the understanding of many of the elements of tokamak physics and the application of this understanding to the design of next generation devices including ITER and CIT. The limitations of magnetohydrodynamics stability on the values of plasma beta (the ratio of kinetic pressure to the containing pressure of the magnetic field) that can be attained has been experimentally demonstrated and found to be described by existing theory. Values of beta (10.7%) well in excess of those required for proposed devices (ITER and CIT) have been demonstrated. Regimes of confinement (H-mode) have been established that scale favorably to proposed next generation devices, and experiments demonstrating the dependence of the energy confinement on plasma size have been completed. Understanding of confinement is rapidly developing especially in the areas of bulk transport and the role of turbulence in the plasma edge. Key experimental results in areas of plasma transport and edge plasma phenomena are found to be in agreement with theories based on short wavelength turbulence. Control of the divertor heat loads and impurity influx has been demonstrated, and new progress has been made in the understanding of plasma edge phenomena. Experiments with ion Bernstein wave heating have not found regimes in which these waves can produce effective central ion heating. Electron cyclotron current drive experiments have demonstrated 70 kA of driven current in 400 kA discharges.

Energy Research Abstracts

Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 486

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Book Description


Government Reports Annual Index

Government Reports Annual Index PDF Author:
Publisher:
ISBN:
Category : Research
Languages : en
Pages : 1646

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Book Description
Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.

Issues in Applied, Analytical, and Imaging Sciences Research: 2011 Edition

Issues in Applied, Analytical, and Imaging Sciences Research: 2011 Edition PDF Author:
Publisher: ScholarlyEditions
ISBN: 1464964106
Category : Science
Languages : en
Pages : 2773

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Book Description
Issues in Applied, Analytical, and Imaging Sciences Research: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Applied, Analytical, and Imaging Sciences Research. The editors have built Issues in Applied, Analytical, and Imaging Sciences Research: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Applied, Analytical, and Imaging Sciences Research in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Applied, Analytical, and Imaging Sciences Research: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Fusion Technology 1994

Fusion Technology 1994 PDF Author: K. Herschbach
Publisher: Newnes
ISBN: 0444599738
Category : Technology & Engineering
Languages : en
Pages : 892

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Book Description
The objective of the Symposium on Fusion Technology (SOFT) conference is to set the stage for the exchange of information on the design, construction, and operation of fusion experiments and the technology which is being developed for the next-step devices and for fusion reactors. These proceedings therefore present an up-to-date and throrough review of the state-of-the art in this dynamic field.

Fusion Technology 1996

Fusion Technology 1996 PDF Author: C. Varandas
Publisher: Elsevier
ISBN: 0444599754
Category : Science
Languages : en
Pages : 1057

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Book Description
The objective of these proceedings was to provide a platform for the exchange of information on the design, construction and operation of fusion experiments. The technology which is being developed for the next step devices and fusion reactors was also covered.

Small Business Innovation Research

Small Business Innovation Research PDF Author: DIANE Publishing Company
Publisher: DIANE Publishing
ISBN: 9780788126598
Category :
Languages : en
Pages : 152

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Book Description
Includes abstracts of the Phase I awards made in FY 1995 under the DOE SBIR program. Covers: novel materials for sustainable energy development, high temperature superconductivity for energy applications, technology and instrumentation for high energy accelerators, natural gas supply, advanced coal-based power systems, hybrid electric vehicle technology, and much more. The work described is novel, high-risk research, but the benefits will also be potentially high if the objectives are met. Brief comments on the potential applications are provided.

An Overview of the DIII-D Program

An Overview of the DIII-D Program PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 9

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Book Description
The DIII-D program focuses on developing fusion physics in an integrated program of tokamak concept improvement. The intent is both to support the present ITER physics R and D and to develop more efficient concepts for the later phases of ITER and eventual power plants. Progress in this effort can be best summarized by recent results for a diverted deuterium discharge with negative central shear which reached a performance level of Q{sub DT} = 0.32. The ongoing development of the tools needed to carry out this program of understanding and optimization continues to be crucial to its success. Control of the plasma cross-sectional shape and the internal distributions of plasma current, density, and rotation has been essential to optimizing plasma performance. Advanced divertor concepts provide edge power and particle control for future devices such as ITER and provide techniques to help manage the edge power and particle flows for advanced tokamak concepts. New divertor diagnostics and improved modeling are developing excellent divertor understanding. Many of the plasma physics issues being posed by ITER are being addressed. Scrapeoff layer power flow is being characterized to provide an accurate basis for the design of reactor devices. Ongoing studies of the density limit focus on identifying ways in which ITER can achieve the required densities in excess of the Greenwald limit. Better understanding of disruptions is crucial to the design of future reactors.