Resistive pressure gradient-driven turbulence at stellarator plasma edge

Journal Article · Mon Sep 01 00:00:00 EDT 1997 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.872469· OSTI ID:538473

Garcia, L ^[1]; Carreras, B A; Lynch, V E; Leboeuf, J N; Newman, D E ^[2]

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1. Universidad Carlos III, Madrid (Spain)
2. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)

High resolution calculations of resistive pressure gradient-driven turbulence for the plasma edge parameters of the Advanced Toroidal Facility (ATF) [J. F. Lyon {ital et al.}, Fusion Technol. {bold 10}, 179 (1986)] electron cyclotron heated discharges give fluctuation levels, consistent with the experimental measurements. This turbulence model is also used to simulate the transition from the low confinement to the high confinement mode. The transition is triggered through the poloidal flow amplification induced by the Reynolds stress. After the transition, the confinement improvement is relatively low (30{percent}{endash}40{percent}), even for unrealistically low poloidal viscosity. In the high confinement mode, the characteristic radial scale length of the poloidal flow in the three-dimensional calculations (separation between the lowest-n resonant surfaces) is different from the single helicity results (radial correlation length of the fluctuations). The simple criterion based on the ratio of shearing rate to the linear growth rate does not quantitatively account for the fluctuation reduction. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 538473
• Journal Information: Physics of Plasmas, Vol. 4, Issue 9; Other Information: PBD: Sep 1997
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION
STELLARATORS
TURBULENCE
PLASMA PRESSURE
PRESSURE GRADIENTS
ATF TORSATRON
PLASMA CONFINEMENT
FLOW STRESS
FLUCTUATIONS