Institution
Oak Ridge National Laboratory
Facility•Oak Ridge, Tennessee, United States•
About: Oak Ridge National Laboratory is a facility organization based out in Oak Ridge, Tennessee, United States. It is known for research contribution in the topics: Neutron & Ion. The organization has 31868 authors who have published 73724 publications receiving 2633689 citations. The organization is also known as: ORNL.
Topics: Neutron, Ion, Scattering, Neutron scattering, Microstructure
Papers published on a yearly basis
Papers
More filters
••
TL;DR: The temperature-dependent characteristics of fluorescence of several rare-earth-doped ceramic phosphors has made these materials the focus of a major effort in the field of noncontact thermometry over the past few decades as mentioned in this paper.
Abstract: The temperature-dependent characteristics of fluorescence of several rare-earth-doped ceramic phosphors has made these materials the focus of a major effort in the field of noncontact thermometry over the past few decades. These “thermographic phosphors,” e.g., Y2O3:Eu, have been used for remote measurements of the temperatures of both static and moving surfaces, and have performed many other tasks that standard sensors (thermocouples, thermistors, etc.) cannot. The range of usefulness of this class of materials extends from cryogenic temperatures to those approaching 2000 °C. The instrumentation needed for this type of thermometry has followed many different lines of development, and this evolution has produced a wide variety of both field- and laboratory-grade systems that are now described in the literature. In general, the technique offers high sensitivity (≈0.05 °C), robustness (e.g., stability of the sensor sample in harsh environments), and NIST traceability. In addition, such systems have been suc...
683 citations
••
TL;DR: In this article, it is shown that this limit may be caused by a dramatic deterioration in core particle confinement occurring as the density limit boundary is approached, which can help explain the disruptions and Marfes that are associated with density limit.
Abstract: While the results of early work on the density limit in tokamaks from the ORMAK and DITE groups have been useful over the years, results from recent experiments and the requirements for extrapolation to future experiments have prompted a new look at this subject. There are many physical processes which limit the attainable densities in tokamak plasmas. These processes include: (1) radiation from low Z impurities, convection, charge exchange and other losses at the plasma edge; (2) radiation from low or high Z impurities in the plasma core; (3) deterioration of particle confinement in the plasma core; and (4) inadequate fuelling, often exacerbated by strong pumping by walls, limiters or divertors. Depending upon the circumstances, any of these processes may dominate and determine a density limit. In general, these mechanisms do not show the same dependence on plasma parameters. The multiplicity of processes leading to density limits with a variety of scaling has led to some confusion when comparing density limits for different machines. The authors attempt to sort out the various limits and to extend the scaling law for one of them to include the important effects of plasma shaping, i.e. ;e = k, where ne is the line average electron density (1020 m−3), κ is the plasma elongation and (MAm−2) is the average plasma current density, defined as the total current divided by the plasma cross-sectional area. In a sense, this is the most important density limit since, together with the q-limit, it yields the maximum operating density for a tokamak plasma. It is shown that this limit may be caused by a dramatic deterioration in core particle confinement occurring as the density limit boundary is approached. This mechanism can help explain the disruptions and Marfes that are associated with the density limit.
682 citations
••
TL;DR: The chemical evolution of seawater during the Phanerozoic is still a matter of debate as mentioned in this paper, and the available data for the composition of fluid inclusions in marine halite and for the mineralogy of marine evaporites.
681 citations
••
TL;DR: It is proposed that the atomic reconstruction at the interface between highly dissimilar structures (such as fluorite and perovskite) provides both a large number of carriers and a high-mobility plane, yielding colossal values of the ionic conductivity.
Abstract: The search for electrolyte materials with high oxygen conductivities is a key step toward reducing the operation temperature of fuel cells, which is currently above 700 degrees C. We report a high lateral ionic conductivity, showing up to eight orders of magnitude enhancement near room temperature, in yttria-stabilized zirconia (YSZ)/strontium titanate epitaxial heterostructures. The enhancement of the conductivity is observed, along with a YSZ layer thickness-independent conductance, showing that it is an interface process. We propose that the atomic reconstruction at the interface between highly dissimilar structures (such as fluorite and perovskite) provides both a large number of carriers and a high-mobility plane, yielding colossal values of the ionic conductivity.
680 citations
••
TL;DR: It is shown that the poloidal momentum balance equation in tokamaks has bifurcated solutions and the theory is employed to explain the {ital L-{ital H} transition observed in toKamaks.
Abstract: It is shown that the poloidal momentum balance equation in tokamaks has bifurcated solutions. The poloidal flow velocity ${U}_{p}$ can suddenly become more positive when the ion collisionality decreases. The corresponding radial electric field ${E}_{r}$ becomes more negative and hence suppresses the turbulent fluctuations. Thus, plasma confinement is improved. The theory is employed to explain the L-H transition observed in tokamaks.
679 citations
Authors
Showing all 32112 results
Name | H-index | Papers | Citations |
---|---|---|---|
Zhong Lin Wang | 245 | 2529 | 259003 |
Hyun-Chul Kim | 176 | 4076 | 183227 |
Bradley Cox | 169 | 2150 | 156200 |
Charles M. Lieber | 165 | 521 | 132811 |
Wei Li | 158 | 1855 | 124748 |
Joseph Jankovic | 153 | 1146 | 93840 |
James M. Tiedje | 150 | 688 | 102287 |
Peter Lang | 140 | 1136 | 98592 |
Andrew G. Clark | 140 | 823 | 123333 |
Josh Moss | 139 | 1019 | 89255 |
Robert H. Purcell | 139 | 666 | 70366 |
Ad Bax | 138 | 486 | 97112 |
George C. Schatz | 137 | 1155 | 94910 |
Daniel Thomas | 134 | 846 | 84224 |
Jerry M. Melillo | 134 | 383 | 68894 |