Download or read book Driving Toroidally Asymmetric Current Through the Tokamak Scrape off Layer Part II written by and published by . This book was released on 2009 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: The structure of the magnetic field perturbations due to non-axisymmetric field-aligned currents in the tokamak scrape-off layer (SOL) are analytically calculated near the X-point. Part I [I. Joseph, et al., submitted to Phys. Plasmas (2008)] demonstrated that biasing divertor target plates in a toroidally asymmetric fashion can generate an appreciable toroidally asymmetric parallel current density in the SOL along the separatrix. Here, the magnetic field perturbation caused by a SOL current channel of finite width and step-wise constant amplitude at the target plate is derived. Flux expansion amplifies the magnetic perturbation near the X-point, while phase interference causes the SOL amplitude to be reduced at large toroidal mode number. Far enough from the current channel, the magnetic field can be approximated as arising from a surface current near the separatrix with differing amplitudes in the SOL and the divertor leg. The perturbation spectrum and resonant components of this field are computed analytically asymptotically close to the separatrix in magnetic flux coordinates. The size of the stochastic layer due to the applied perturbation that would result without self-consistent plasma shielding is also estimated. If enough resonant field is generated, control of the edge pressure gradient may allow stabilization of edge localized modes.
Download or read book Driving Toroidally Asymmetric Current Through the Tokamak Scrape off Layer Part I written by and published by . This book was released on 2009 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: A potential technique for suppressing edge localized magnetohydrodynamic instabilities (ELMs) is theoretically analyzed. Recent experiments have shown that externally generated resonant magnetic perturbations (RMPs) can stabilize ELMs by modifying the density profile [T.E. Evans, et al., Nature Phys. 2, 419 (2006); Y. Liang, et al., Phys. Rev. Lett. 98, 265004 (2007)]. Driving toroidally asymmetric current internally, through the scrape-off layer (SOL) plasma itself, can also generate RMPs that are close to the required threshold for ELM control. The limiting ion saturation current densities can be achieved by producing potential differences on the order of the electron temperature. Although the threshold is uncertain in future devices, if driven coherently though the SOL, the upper limit for the resulting field would exceed the present experimental threshold. This analysis provides the tools required for estimating the magnitude of the coherent SOL current and RMP generated via toroidally asymmetric biasing of the target. Flux expansion increases the RMP near the X-point, while phase interference due to the shearing of field lines near the X-point reduces the amplitude of the effective SOL perturbation and makes the result sensitive to both toroidal mode number n and the radial coherence width of the biasing region. If the limiting current density decays rapidly enough radially, both the width and the amplitude of the current density drawn from the target will be reduced. The RMP can still exceed the present threshold at low n if the radial location and width of the biasing region are optimally chosen.
Download or read book Driving Toroidally Asymmetric Current Through the Tokamak Scrape Off Layer to Control Edge Localized Instabilities and Equilibrium Profiles written by and published by . This book was released on 2010 with total page 10 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 1989 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scrape off Layer Flows Magnetic Topology and Influence on the L H Threshold in a Tokamak written by Brian LaBombard and published by . This book was released on 2004 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dependence of L-H power threshold on magnetic topology (upper-, lower-null) in a tokamak is linked to near-sonic plasma flows in the high-field side scrape-off layer. Scrape-off layer flow momentum, coupling across the separatrix, imparts a topology-dependent increment to edge and core toroidal rotation (counter-, co-current). In all topologies, rotation increases in the co-current direction with input power: the L-H transition is seen when co-rotation achieves a characteristic level. Correspondingly, higher power is required to attain H-modes in upper- versus lower-null (with BxGradB down).
Download or read book Fusion Nucl aire written by and published by . This book was released on 1998 with total page 648 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 1992 with total page 604 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 1058 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 1986 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ICPP 1994 written by P. H. Sakanaka and published by American Institute of Physics. This book was released on 1995 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Invited papers delivered at ICPP 1994, which is the joint conference of the 10th Kiev International Conference on Plasma Theory and the 10th International Congress on Waves and Instabilities in Plasmas. In addition to summary talks and an opening colloquium on solar eclipses, subjects addressed incl
Download or read book New Ideas in Tokamak Confinement written by Marshall N. Rosenbluth and published by Springer Science & Business Media. This book was released on 1997-05-08 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Market: Scientists and students involved in thermonuclear fusion research. Thermonuclear fusion research using the confinement device tokamak represents one of the most prominent science projects in the second half of the 20th century. International Tokamak Community is now committing significant effort and funds to experiments with burning plasma, hot and dense enough to produce significant nuclear fusion reactions. The methods used to enhance tokamak performance have a profound and immediate effect on machine design. This book provides an up-to-date account of research in tokamak fusion and puts forward innovative ideas in confinement physics.
Download or read book Chinese Physics Letters written by and published by . This book was released on 2003 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1986 with total page 890 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Euroabstracts written by and published by . This book was released on 1994 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Documentation of Plasma Physics Pt 1 Experimental Plasma Physics and Theoretical Plasma Physics written by and published by . This book was released on 1980 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindex written by and published by . This book was released on 1988 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Europhysics Conference Abstracts written by and published by . This book was released on 1975 with total page 1112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
