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Title: Theory of the L-H transition

Abstract

The theory of the L-H transition in tokamaks is discussed. A transport bifurcation model is presented, which predicts reasonably well several properties of the L-H transition in the DIII-D tokamak, including the evolution in time of the density and temperature profiles. A bifurcation in the radial transport occurs because of a nonlinear feedback mechanism involving the radial electric field. A spontaneous transition is predicted when certain conditions are met; no trigger mechanism is necessary. The predicted profile evolution in H-mode can include a transition to VH-mode, with its characteristically wider transport barrier at the plasma edge. Trigger mechanisms are discussed, as well as the idea of considering the L-H transition as a phase transition.

Authors:
Publication Date:
Research Org.:
General Atomics, San Diego, CA (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
10189786
Report Number(s):
GA-A-21778; CONF-9408176-1
ON: DE95001389; BR: 35AT10020/35KC07000; TRN: 94:022650
DOE Contract Number:
AC03-89ER51114
Resource Type:
Technical Report
Resource Relation:
Conference: ISPP workshop on the theory of fusion plasmas,Varenna (Italy),22-26 Aug 1994; Other Information: PBD: Sep 1994
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; TOKAMAK DEVICES; PLASMA CONFINEMENT; PLASMA SIMULATION; H-MODE PLASMA CONFINEMENT; TURBULENCE; PLASMA DRIFT; THEORETICAL DATA; CHARGED-PARTICLE TRANSPORT; PLASMA DENSITY; 700310

Citation Formats

Hinton, F.L. Theory of the L-H transition. United States: N. p., 1994. Web. doi:10.2172/10189786.
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Hinton, F.L. Theory of the L-H transition. United States. doi:10.2172/10189786.
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Hinton, F.L. Thu . "Theory of the L-H transition". United States. doi:10.2172/10189786. https://www.osti.gov/servlets/purl/10189786.
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@article{osti_10189786,
title = {Theory of the L-H transition},
author = {Hinton, F.L.},
abstractNote = {The theory of the L-H transition in tokamaks is discussed. A transport bifurcation model is presented, which predicts reasonably well several properties of the L-H transition in the DIII-D tokamak, including the evolution in time of the density and temperature profiles. A bifurcation in the radial transport occurs because of a nonlinear feedback mechanism involving the radial electric field. A spontaneous transition is predicted when certain conditions are met; no trigger mechanism is necessary. The predicted profile evolution in H-mode can include a transition to VH-mode, with its characteristically wider transport barrier at the plasma edge. Trigger mechanisms are discussed, as well as the idea of considering the L-H transition as a phase transition.},
doi = {10.2172/10189786},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Sep 01 00:00:00 EDT 1994},
month = {Thu Sep 01 00:00:00 EDT 1994}
}
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Technical Report:
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DOI:  10.2172/10189786
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