Influence of the boundary conditions on the H-mode power threshold

Journal Article · Wed Mar 15 00:00:00 EST 2006 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2178176· OSTI ID:20782557

Kalupin, D; Tokar, M Z; Unterberg, B; Loozen, X; Pilipenko, D; Zagorski, R ^[1]

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1. Institut fuer Plasmaphysik, Forschungszentrum Juelich GmbH, EURATOM Association, D-52425 Juelich (Germany)

The effect of boundary conditions at the last closed magnetic surface (LCMS) on the formation of the edge transport barrier (ETB) in tokamaks is investigated by one-dimensional transport calculations for the radial profiles of plasma parameters. For a given heating power the transition from the low confinement mode (L mode) to the high confinement mode (H mode) can be triggered by increasing the density e-folding length, {delta}{sub n}, or reducing the temperature e-folding length, {delta}{sub T}, at the LCMS. This is explained by the decrease of heat losses from the confined plasma with the convection of charged particles and changeover to the case where losses are mostly due to heat conduction. In such a case, corresponding to a divertor configuration, the computed power threshold for the L- to H-mode transition (L-H transition) is in a good agreement with the experimental multimachine scaling.

• OSTI ID: 20782557
• Journal Information: Physics of Plasmas, Vol. 13, Issue 3; Other Information: DOI: 10.1063/1.2178176; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BOUNDARY CONDITIONS
BOUNDARY LAYERS
CHARGED PARTICLES
CHARGED-PARTICLE TRANSPORT
CONVECTION
DIVERTORS
ELECTRON TEMPERATURE
H-MODE PLASMA CONFINEMENT
HEAT LOSSES
ION TEMPERATURE
L-MODE PLASMA CONFINEMENT
MAGNETIC SURFACES
PLASMA
PLASMA DENSITY
PLASMA INSTABILITY
THERMAL CONDUCTION
TOKAMAK DEVICES