A semi-analytic power balance model for low (L) to high (H) mode transition power threshold
Journal article, 2014

We present a semi-analytic model for low (L) to high (H) mode transition power threshold (P-th). Two main assumptions are made in our study. First, high poloidal mode number drift resistive ballooning modes (high-m DRBM) are assumed to be the dominant turbulence driver in a narrow edge region near to last closed flux surface. Second, the pre-transition edge profile and turbulent diffusivity at the narrow edge region pertain to turbulent equipartition. An edge power balance relation is derived by calculating the dissipated power flux through both turbulent conduction and convection, and radiation in the edge region. P-th is obtained by imposing the turbulence quench rule due to sheared E x B rotation. Evaluation of P-th shows a good agreement with experimental results in existing machines. Increase of P-th at low density (i.e., the existence of roll-over density in P-th vs. density) is shown to originate from the longer scale length of the density profile than that of the temperature profile.

Author

R Singh

Institute for Plasma Research India

National Fusion Research Institute

H. Jhang

National Fusion Research Institute

P.K. Kaw

Institute for Plasma Research India

P. H. Diamond

University of California

National Fusion Research Institute

Hans Nordman

Chalmers, Earth and Space Sciences, Plasma Physics and Fusion Energy

C Bourdelle

The French Alternative Energies and Atomic Energy Commission (CEA)

A Loarte

ITER Organization

Physics of Plasmas

1070-664X (ISSN) 1089-7674 (eISSN)

Vol. 21 6 062503- 062503

Driving Forces

Sustainable development

Areas of Advance

Energy

Roots

Basic sciences

Subject Categories

Fusion, Plasma and Space Physics

DOI

10.1063/1.4882256

More information

Latest update

4/11/2018