Institution
Princeton Plasma Physics Laboratory
Facility•Plainsboro Center, New Jersey, United States•
About: Princeton Plasma Physics Laboratory is a facility organization based out in Plainsboro Center, New Jersey, United States. It is known for research contribution in the topics: Tokamak & Plasma. The organization has 2427 authors who have published 4475 publications receiving 106926 citations. The organization is also known as: PPPL.
Topics: Tokamak, Plasma, Divertor, Magnetic field, Magnetic confinement fusion
Papers published on a yearly basis
Papers
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TL;DR: Turbulent fluctuations in plasmas with reversed magnetic shear investigated on the Tokamak Fusion Test Reactor are found to be consistent with the suppression of turbulence by the E x B velocity shear.
Abstract: Turbulent fluctuations in plasmas with reversed magnetic shear have been investigated on the Tokamak Fusion Test Reactor. Under intense auxiliary heating, these plasmas are observed to bifurcate into two states with different transport properties. In the state with better confinement, it has been found that the level of fluctuations is very small throughout most of the region with negative shear. By contrast, the state with lower confinement is characterized by large bursts of fluctuations which suggest a competition between the driving and the suppression of turbulence. These results are consistent with the suppression of turbulence by the $\mathbf{E}\ifmmode\times\else\texttimes\fi{}\mathbf{B}$ velocity shear.
173 citations
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TL;DR: In this article, the ion temperature gradient-driven instability is considered and the saturation of a single eddy is modeled by a simple nonlinear equation, and it is shown that eddies that are elongated in the direction of the temperature gradient are the most unstable and have the highest saturation amplitudes.
Abstract: The ion‐temperature‐gradient‐driven instability is considered in this paper. Physical pictures are presented to clarify the nature of the instability. The saturation of a single eddy is modeled by a simple nonlinear equation. It is shown that eddies that are elongated in the direction of the temperature gradient are the most unstable and have the highest saturation amplitudes. In a sheared magnetic field, such elongated eddies twist with the field lines. This structure is shown to be an alternative to the usual Fourier mode picture in which the mode is localized around the surface where k∥ =0. These elongated twisting eddies, which are an integral part of the ‘‘ballooning mode’’ structure, could survive in a torus. The elongated eddies are shown to be unstable to secondary instabilities that are driven by the large gradients in the long eddy. It is argued that the ‘‘mixing length’’ is affected by this nonlinear process, and is unlikely to be a linear eigenmode width.
171 citations
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TL;DR: In this paper, the current conducted across the magnetic field via a rotating spoke has been directly measured for the first time in the E × B discharge of a cylindrical Hall thruster.
Abstract: Rotating spoke phenomena have been observed in a variety of Hall thruster and other E × B devices. It has been suggested that the spoke may be associated with the enhancement of the electron cross-field transport. In this paper, the current conducted across the magnetic field via a rotating spoke has been directly measured for the first time in the E × B discharge of a cylindrical Hall thruster. The spoke current was measured using a segmented anode. Synchronized measurements with a high speed camera and a four-segment anode allow observation of the current as a function of time and azimuthal position. Upwards of 50% of the total current is conducted through the spoke, which occupies a quarter of the Hall thruster channel area. To determine the transport mechanism, emissive and Langmuir probes were installed to measure fluctuating plasma potential, electron density, and temperature. A perturbed, azimuthal electric field and density are observed to oscillate in-phase with the rotating spoke. The resulting ...
169 citations
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TL;DR: Mc McGuire et al. as discussed by the authors showed that the amount of lithium on the limiter and the effectiveness of its action can be maximized through injecting four Li pellets into Ohmic plasmas of increasing major and minor radius.
Abstract: Wall conditioning in the Tokamak Fusion Test Reactor (TFTR) [K. M. McGuire et al., Phys. Plasmas 2, 2176 (1995)] by injection of lithium pellets into the plasma has resulted in large improvements in deuterium–tritium fusion power production (up to 10.7 MW), the Lawson triple product (up to 1021 m−3 s keV), and energy confinement time (up to 330 ms). The maximum plasma current for access to high‐performance supershots has been increased from 1.9 to 2.7 MA, leading to stable operation at plasma stored energy values greater than 5 MJ. The amount of lithium on the limiter and the effectiveness of its action are maximized through (1) distributing the Li over the limiter surface by injection of four Li pellets into Ohmic plasmas of increasing major and minor radius, and (2) injection of four Li pellets into the Ohmic phase of supershot discharges before neutral‐beam heating is begun.
168 citations
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TL;DR: In this paper, a Thomson scattering system is developed for Joint European Torus with 15"mm spatial resolution and a foreseen accuracy for temperature better than 15% at a density of 1019"m−3.
Abstract: A Thomson scattering system is being developed for Joint European Torus with 15 mm spatial resolution and a foreseen accuracy for temperature better than 15% at a density of 1019 m−3. This resolution is required at the internal transport barrier and edge pedestal and it can not be fully achieved with the present light detection and ranging systems. The laser for this system is Nd:YAG, 5 Joule, 20 Hz. Scattering volumes from R=2.9 m to R=3.9 m are imaged onto 1 mm diameter fibers, with F/25 collection aperture. Two fibers are used per scattering volume. Using optical delay lines, three scattering volumes are combined in each of the 21 filter polychromators. The signals are recorded with transient digitizers, which allow the combined time delayed signals to be resolved. Knowledge of the time delay between signals allows the use of correlation techniques in determining signal levels. The ac output of the amplifier is used, which tolerates a higher level of background signal without affecting dynamic range. T...
165 citations
Authors
Showing all 2454 results
Name | H-index | Papers | Citations |
---|---|---|---|
David W. Johnson | 160 | 2714 | 140778 |
Kazuhiko Hara | 141 | 1956 | 107697 |
David R. Smith | 110 | 881 | 91683 |
Hantao Ji | 105 | 793 | 42035 |
David J. McComas | 97 | 794 | 38120 |
James R. Wilson | 89 | 1271 | 37470 |
Bruce M. Jakosky | 71 | 441 | 20916 |
Patrick Diamond | 71 | 604 | 22522 |
Roger V. Yelle | 69 | 299 | 14469 |
Kwan-Liu Ma | 65 | 526 | 15442 |
Liu Chen | 64 | 343 | 16067 |
Gennady Shvets | 64 | 449 | 19516 |
David B. Graves | 64 | 278 | 15173 |
Brian LaBombard | 63 | 383 | 13721 |
Amitava Bhattacharjee | 61 | 481 | 14428 |