A fluid theory of ion collection by probes in strong magnetic fields with plasma flow
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TLDR
It is clear that the value assumed for the momentum diffusivity strongly affects the interpretation of recent probe measurements, and it is argued that the present results offer a more reliable basis for this interpretation.Abstract:
A one‐dimensional fluid theory of Langmuir probe operation in strong magnetic fields is presented. Cross‐field diffusion of ions both into and out of the the collection region is consistently accounted for, in effect taking momentum and particle diffusivity to be equal. The results differ by significant factors from previous analyses, which did not account for outward diffusion but in effect set momentum diffusivity to zero. The differences are especially large when parallel flow of the external plasma is present. It is thus clear that the value assumed for the momentum diffusivity strongly affects the interpretation of recent probe measurements. It is argued that the present results offer a more reliable basis for this interpretation.read more
Citations
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Journal ArticleDOI
Particle transport in the scrape-off layer and its relationship to discharge density limit in Alcator C-Mod
Brian LaBombard,R. L. Boivin,Martin Greenwald,J. W. Hughes,Bruce Lipschultz,D. A. Mossessian,C. S. Pitcher,J. L. Terry,S. J. Zweben +8 more
TL;DR: In this paper, an effective particle diffusivity (Deff) that increases markedly with distance from the separatrix is characterized by a two-layer structure: Steep gradients and moderate fluctuation levels are typically found in a ∼5 mm region near the separation point, where parallel electron conduction typically dominates energy losses.
Journal ArticleDOI
Cross-field plasma transport and main-chamber recycling in diverted plasmas on Alcator C-Mod
Brian LaBombard,M.V. Umansky,R.L. Boivin,J.A. Goetz,J. W. Hughes,Bruce Lipschultz,D. A. Mossessian,C. S. Pitcher,J. L. Terry +8 more
TL;DR: In this paper, the main-chamber recycling regime in the Alcator C-mod regime was studied, where most of the plasma particle efflux recycles on the main chamber walls rather than flows into the divertor volume.
Journal ArticleDOI
Experimental investigation of transport phenomena in the scrape-off layer and divertor
Brian LaBombard,J.A. Goetz,Ian H. Hutchinson,D. Jablonski,Jay Kesner,C. Kurz,Bruce Lipschultz,G.M. McCracken,A. Niemczewski,J. L. Terry,A. J. Allen,R.L. Boivin,F. Bombarda,P.T. Bonoli,C. Christensen,C.L. Fiore,D. T. Garnier,S. Golovato,Robert Granetz,Martin Greenwald,S. Horne,Amanda Hubbard,James Irby,D. Lo,D. Lumma,Earl Marmar,M. J. May,A. Mazurenko,R. Nachtrieb,H. Ohkawa,P. O’Shea,Miklos Porkolab,J. Reardon,John Rice,J. C. Rost,J. Schachter,J.A. Snipes,J. Sorci,P. Stek,Yuichi Takase,Y. Wang,R. Watterson,J.L. Weaver,B. Welch,Scot A. Wolfe +44 more
TL;DR: In this paper, the authors investigated the divertor and scrape-off layer of Alcator C-Mod for a wide range of plasma conditions, including low recycling, high-recycling, and detached regimes, and reversed divertor flows.
Journal ArticleDOI
Tokamak plasma diagnosis by electrical probes
TL;DR: In this article, a review of advances in the understanding and application of electrical probes for the diagnosis of tokamak edge plasmas is presented, where the importance of measuring the parallel flow velocity in the plasma edge is highlighted and recent developments in theories for interpretation of Mach probes are discussed.
Journal ArticleDOI
Gundestrup: A Langmuir/Mach probe array for measuring flows in the scrape‐off layer of TdeV
TL;DR: Gundestrup as mentioned in this paper is a Langmuir/Mach probe array which measures the flow velocity in the scrape-off layer of TdeV, based on the concept of a Mach probe where presheaths extending upstream and downstream from the probe, parallel to the magnetic field, attract charge to a circular array of collecting pins.
References
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Book
Principles of Plasma Diagnostics
TL;DR: In this paper, the authors introduce a glossary of fast ions and fusion products, including fast ions, fast ion, and fast ion fusion products and their applications in the field of magnetic diagnostics.
Book
The characteristics of electrical discharges in magnetic fields
Andrew Guthrie,R. K. Wakerling +1 more
Journal ArticleDOI
A General Theory of the Plasma of an Arc
Lewi Tonks,Irving Langmuir +1 more
TL;DR: In this paper, the potential distribution of the potential difference between the center and the edge of the sheath of a single probe wire is calculated for the case where the probe wires are attached to the wall of a cylindrical spherical plasmas.
Journal ArticleDOI
Electric sheath and presheath in a collisionless, finite ion temperature plasma
TL;DR: In this article, a collisionless plasma with arbitrary ion temperature in plane geometry is formulated and the plasma-sheath equation is solved numerically with no approximation of the Debye length.
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