Reducing Turbulent Transport in Toroidal Configurations via Shaping
Authors: H.E. Mynick, N. Pomphrey and P. Xanthopoulos
Abstract: Recent progress in reducing turbulent transport in stellarators and tokamaks by
3D shaping using a stellarator optimization code in conjunction with a gyrokinetic
code is presented. The original applications of the method focussed on ion temperature
gradient transport in a quasi-axisymmetric stellarator design. Here, an
examination of both other turbulence channels and other starting configurations is
initiated. It is found that the designs evolved for transport from ion temperature
gradient turbulence also display reduced transport from other transport channels
whose modes are also stabilized by improved curvature, such as electron temperature
gradient and ballooning modes. The optimizer is also applied to evolving from
a tokamak, finding appreciable turbulence reduction for these devices as well. From
these studies, improved understanding is obtained of why the deformations found by
the optimizer are beneficial, and these deformations are related to earlier theoretical
work in both stellarators and tokamaks.
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Submitted to: Physics of Plasmas (November 2010)
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Download PPPL-4613 (pdf 1.03MB 13 pp)
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