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arXiv · 1105.2195

An Enhanced Nonlinear Critical Gradient for Electron Turbulent Transport due to Reversed Magnetic Shear

J. L. Peterson·G. W. Hammett·D. R. Mikkelsen·H. Y. Yuh·J. Candy·W. Guttenfelder·S. M. Kaye·B. LeBlanc
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Abstract

The first nonlinear gyrokinetic simulations of electron internal transport barriers (e-ITBs) in the National Spherical Torus Experiment show that reversed magnetic shear can suppress thermal transport by increasing the nonlinear critical gradient for electron-temperature-gradient-driven turbulence to three times its linear critical value. An interesting feature of this turbulence is nonlinearly driven off-midplane radial streamers. This work reinforces the experimental observation that magnetic shear is likely an effective way of triggering and sustaining e-ITBs in magnetic fusion devices.

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J. L. Peterson, G. W. Hammett, D. R. Mikkelsen, H. Y. Yuh, J. Candy, W. Guttenfelder, S. M. Kaye, B. LeBlanc. 2011-05-11. An Enhanced Nonlinear Critical Gradient for Electron Turbulent Transport due to Reversed Magnetic Shear. https://doi.org/10.2172/1013257

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