Ion temperature gradient mode in the weak density gradient limit
- 1 October 1988
- journal article
- letter
- Published by AIP Publishing in Physics of Fluids
- Vol. 31 (10), 3147-3150
- https://doi.org/10.1063/1.867024
Abstract
The toroidal ion temperature gradient mode (ITG mode) is analyzed in the fluid limit for flat density profiles, typical of many H‐mode plasmas. It is shown that the stability boundary is not Ln/LTi=const ≊O(1 ■2) (Ln and LTi are the density and ion temperature gradient scale lengths, respectively), as typically quoted. Rather, for large Ln/R the stability threshold is characterized by LTi/R =const≊O(0.1) with R the major radius. This result could substantially reduce the impact of ITG‐mode turbulence, allowing a reconciliation of present drift wave transport models with improved H‐mode energy confinement.Keywords
This publication has 14 references indexed in Scilit:
- Transport simulations of Ohmic TFTR experiments with microinstability based, profile consistent models for electron and ion thermal transportNuclear Fusion, 1987
- Observation of a high-density ion mode in tokamak microturbulencePhysical Review Letters, 1987
- Tokamak transport code simulations with drift wave modelsNuclear Fusion, 1987
- Microinstabilities in weak density gradient tokamak systemsPhysics of Fluids, 1986
- Experimentally inferred ion thermal diffusivity profiles in the Doublet III tokamak: Comparison with neoclassical theoryNuclear Fusion, 1986
- Non-ideal ballooning modes in a tokamakNuclear Fusion, 1986
- A review of energy confinement and local transport scaling results in neutral-beam-heated tokamaksPhysics of Fluids, 1985
- Ion-temperature-gradient instability in toroidal plasmasPhysics of Fluids, 1983
- Electrostatic drift waves in tokamaks: a numerical study of instability and transportNuclear Fusion, 1980
- Microinstability theory in tokamaksNuclear Fusion, 1978