Measurements and Scalings of the H-mode Pedestal on Alcator C-Mod

Measurements and Scalings of the H-mode Pedestal on Alcator C-Mod PDF Author: Dmitri A. Mossessian
Publisher:
ISBN:
Category :
Languages : en
Pages : 17

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Measurements and Scalings of the H-mode Pedestal on Alcator C-Mod

Measurements and Scalings of the H-mode Pedestal on Alcator C-Mod PDF Author: Dmitri A. Mossessian
Publisher:
ISBN:
Category :
Languages : en
Pages : 17

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Observations and Empirical Scalings of the High-confinement Mode Pedestal on Alcator C-Mod

Observations and Empirical Scalings of the High-confinement Mode Pedestal on Alcator C-Mod PDF Author: J. W. Hughes
Publisher:
ISBN:
Category :
Languages : en
Pages : 50

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On the Alcator C-Mod tokamak [Phys. Plasmas 1, 1511, (1994)], radial profiles of electron temperature (Te) and density (ne) are measured at the plasma edge with millimeter resolution Thomson scattering [Rev. Sci. Instrum. 72, 1107 (2001)]. Edge transport barriers in the high confinement regime (H-mode) exhibit Te, ne pedestals with typical widths of 2-6 mm, with the Te pedestal on average slightly wider than and inside the ne pedestal. Measurements at both the top and the base of the pedestal are consistent with profiles obtained using other diagnostics. The two primary H-mode regimes on C-Mod, enhanced Da (EDA) and edge-localized mode free (ELM-free), have been examined for differences in pedestals. EDA operation is favored by high edge collisionality n*, in addition to high edge safety factor q95. Scaling studies at fixed shape yield little systematic variation of pedestal widths with plasma parameters, though higher triangularity is seen to increase the ne pedestal width dramatically. Pedestal heights and gradients show the clearest dependencies on plasma control parameters. Pedestal ne and Te both scale linearly with plasma current IP, while pedestal Te depends strongly on power flowing from the core plasma into the scrape-off layer PSOL. The electron pressure (pe) pedestal and pe gradient both scale with IP2 PSOL1/2. Plasma stored energy WP scales with pedestal pe, implying that pedestal scalings may in large part determine global confinement scalings.

Advances in Measurement and Modeling of the High-confinement-mode Pedestal on the Alcator C-Mod Tokamak

Advances in Measurement and Modeling of the High-confinement-mode Pedestal on the Alcator C-Mod Tokamak PDF Author: Jerry Wayne Hughes
Publisher:
ISBN:
Category :
Languages : en
Pages : 52

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Edge transport barrier (ETB) studies on the Alcator C-Mod tokamak [Phys. Plasmas 1, 1511, (1994)] investigate pedestal scalings and radial transport of plasma and neutrals. Pedestal profiles show trends with plasma operational parameters such as total current IP . A ballooning-like I2P dependence is seen in the pressure gradient, despite calculated stability to ideal ballooning modes. A similar scaling is seen in the near scrape-off-layer for both low-confinement (L-mode) and H-mode discharges, possibly due to electromagnetic fluid drift turbulence setting transport near the separatrix. Neutral density diagnosis allows examination of D0 fueling in H-modes, yielding profiles of effective particle diffusivity in the ETB, which vary as IP is changed. Edge neutral transport is studied using a 1D kinetic treatment. In both experiment and modeling, the C-Mod density pedestal exhibits a weakly increasing pedestal density and a nearly invariant density pedestal width as the D0 source rate increases. Identical modeling performed on pedestal profiles typical of DIII-D [Nucl. Fusion 42, 614, (2002)] reveal differences in pedestal scalings qualitatively similar to experimental results.

Fusion Science and Technology

Fusion Science and Technology PDF Author:
Publisher:
ISBN:
Category : Fusion reactors
Languages : en
Pages : 512

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Magnetic Fusion Energy

Magnetic Fusion Energy PDF Author: George Neilson
Publisher: Woodhead Publishing
ISBN: 0081003269
Category : Science
Languages : en
Pages : 634

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Book Description
Magnetic Fusion Energy: From Experiments to Power Plants is a timely exploration of the field, giving readers an understanding of the experiments that brought us to the threshold of the ITER era, as well as the physics and technology research needed to take us beyond ITER to commercial fusion power plants. With the start of ITER construction, the world's magnetic fusion energy (MFE) enterprise has begun a new era. The ITER scientific and technical (S&T) basis is the result of research on many fusion plasma physics experiments over a period of decades. Besides ITER, the scope of fusion research must be broadened to create the S&T basis for practical fusion power plants, systems that will continuously convert the energy released from a burning plasma to usable electricity, operating for years with only occasional interruptions for scheduled maintenance. - Provides researchers in academia and industry with an authoritative overview of the significant fusion energy experiments - Considers the pathway towards future development of magnetic fusion energy power plants - Contains experts contributions from editors and others who are well known in the field

Diagnostics for Experimental Thermonuclear Fusion Reactors 2

Diagnostics for Experimental Thermonuclear Fusion Reactors 2 PDF Author: Peter E. Stott
Publisher: Springer Science & Business Media
ISBN: 1461553539
Category : Science
Languages : en
Pages : 615

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Book Description
This book of proceedings collects the papers presented at the workshop on "Diagnostics for Experimental Fusion Reactors" held at Villa Monastero, Varenna (Italy) September 4-12, 1997. This workshop was the seventh organized by the International School of Plasma Physics "Piero Caldirola" on the topic of plasma diagnostics and the second devoted to the diagnostic studies for the International Thermonuclear Experimental Reactor (ITER). The proceedings of the first workshop on ITER diagnostics were published by Plenum Press in 1996 with the title "Diagnostics for Experimental Thermonuclear Fusion Reactors". While many of the ideas and studies reported in the first workshop remain valid, there has been sub stantial progress in the design and specification of many diagnostics for ITER. This moti vated a second workshop on this topic and the publication of a new book of proceedings. ITER is a joint venture between Europe, Japan, Russia and USA in the field of con trolled thermonuclear fusion research. The present aim of ITER is to design an experimental fusion reactor that can demonstrate ignition and sustained burn in a magnetically confined plasma. To achieve this goal, a wide range of plasma parameters will have to be measured reliably. It is also anticipated that diagnostics will be used much more extensively as input to control systems on ITER than on present fusion devices and this will require increased relia bility and long-term stability.

Fusion Nucléaire

Fusion Nucléaire PDF Author:
Publisher:
ISBN:
Category : Electronic journals
Languages : en
Pages : 532

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Driven Rotation, Self-Generated Flow, and Momentum Transport in Tokamak Plasmas

Driven Rotation, Self-Generated Flow, and Momentum Transport in Tokamak Plasmas PDF Author: John Rice
Publisher: Springer Nature
ISBN: 3030922669
Category : Science
Languages : en
Pages : 158

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Book Description
This book provides a comprehensive look at the state of the art of externally driven and self-generated rotation as well as momentum transport in tokamak plasmas. In addition to recent developments, the book includes a review of rotation measurement techniques, measurements of directly and indirectly driven rotation, momentum sinks, self-generated flow, and momentum transport. These results are presented alongside summaries of prevailing theory and are compared to predictions, bringing together both experimental and theoretical perspectives for a broad look at the field. Both researchers and graduate students in the field of plasma physics will find this book to be a useful reference. Although there is an emphasis on tokamaks, a number of the concepts are also relevant to other configurations.

Doppler Measurements in the Edge of the Alcator C-Mod Tokamak Using a High-resolution Visible Spectrometer

Doppler Measurements in the Edge of the Alcator C-Mod Tokamak Using a High-resolution Visible Spectrometer PDF Author: Alexander Turner Graf
Publisher:
ISBN:
Category :
Languages : en
Pages : 390

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H-modes on Alcator C-mod

H-modes on Alcator C-mod PDF Author: Joseph Allan Snipes
Publisher:
ISBN:
Category :
Languages : en
Pages : 10

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