Zero-turbulence manifold in a toroidal plasma

E. G. Highcock, A. A. Schekochihin, S. C. Cowley, M. Barnes, F. I. Parra, C. M. Roach, W. Dorland

Research output: Contribution to journalArticle

26 Scopus citations

Abstract

Sheared toroidal flows can cause bifurcations to zero-turbulent-transport states in tokamak plasmas. The maximum temperature gradients that can be reached are limited by subcritical turbulence driven by the parallel velocity gradient. Here it is shown that q/Ïμ (magnetic field pitch/inverse aspect ratio) is a critical control parameter for sheared tokamak turbulence. By reducing q/Ïμ, far higher temperature gradients can be achieved without triggering turbulence, in some instances comparable to those found experimentally in transport barriers. The zero-turbulence manifold is mapped out, in the zero-magnetic-shear limit, over the parameter space (γE, q/Ïμ, R/LT), where γE is the perpendicular flow shear and R/LT is the normalized inverse temperature gradient scale. The extent to which it can be constructed from linear theory is discussed.

Original languageEnglish (US)
Article number265001
JournalPhysical review letters
Volume109
Issue number26
DOIs
StatePublished - Dec 27 2012
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Zero-turbulence manifold in a toroidal plasma'. Together they form a unique fingerprint.

Cite this