Thermal confinement bifurcation and the L- to H-mode transition in tokamaks

Journal Article · Fri Mar 01 04:00:00 EST 1991 · Physics of Fluids B; (USA)

DOI:https://doi.org/10.1063/1.859866· OSTI ID:5694660

Hinton, F L ^[1]

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1. General Atomics, San Diego, California 92186-9784 (US)

A bifurcation in the thermal confinement of tokamaks, which resembles the L- to H-mode transition, is shown to follow from properties of edge turbulence recently derived by Biglari {ital et} {ital al}. (Phys. Fluids B {bold 2}, 1 (1990)), and the standard neoclassical theory of poloidal rotation. The temperature profiles develop a pedestal at the plasma edge, and the poloidal rotation near the edge is considerably increased, when the heating power exceeds a critical value. The energy confinement time is a discontinuous function of increasing heating power, but is continuous for decreasing power (power hysteresis). Critical values of density and magnetic field are found, which must be exceeded in order for the bifurcation to occur. The scaling of the power threshold with density, magnetic field, and ion mass is similar to what is found experimentally.

• OSTI ID: 5694660
• Journal Information: Physics of Fluids B; (USA), Journal Name: Physics of Fluids B; (USA) Vol. 3:3; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
CLOSED PLASMA DEVICES
CONFINEMENT
ENERGY
HEATING
INSTABILITY
MAGNETIC FIELDS
MOTION
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA HEATING
PLASMA INSTABILITY
ROTATION
SCALING LAWS
TEMPERATURE DISTRIBUTION
THERMONUCLEAR DEVICES
THRESHOLD ENERGY
TOKAMAK DEVICES
TURBULENCE