Phase Space of Tokamak Edge Turbulence, the <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="italic">L</mi><mi>−</mi><mi mathvariant="italic">H</mi></math></span> Transition, and the Formation of the Edge Pedestal

B. N. Rogers; J. F. Drake; A. Zeiler

doi:10.1103/PhysRevLett.81.4396

Phase Space of Tokamak Edge Turbulence, the $L - H$ Transition, and the Formation of the Edge Pedestal

B. N. Rogers, J. F. Drake, and A. Zeiler

Phys. Rev. Lett. 81, 4396 – Published 16 November 1998

Abstract

Based on three-dimensional simulations of the Braginskii equations, we identify two main parameters which control transport in the edge of tokamaks: the MHD ballooning parameter and a diamagnetic parameter. The space defined by these parameters delineates regions where typical $L$ -mode levels of transport arise, where the transport is catastrophically large (density limit) and where the plasma spontaneously forms a transport barrier ( $H$ mode).