Ion‐temperature‐gradient modes in noncircular tokamak geometry
| Autor: | X. Q. Xu, D. D. Hua, T. K. Fowler |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Fluid Flow and Transfer Processes
Physics Tokamak Gyroradius Mathematics::Optimization and Control Computational Mechanics Vlasov equation General Physics and Astronomy Geometry Plasma Condensed Matter Physics Thermal diffusivity law.invention Temperature gradient Physics::Plasma Physics Computer Science::Systems and Control Mechanics of Materials law Wavenumber Scaling |
| Zdroj: | Physics of Fluids B: Plasma Physics. 4:3216-3225 |
| ISSN: | 0899-8221 |
| DOI: | 10.1063/1.860377 |
| Popis: | The work of Xu and Rosenbluth [Phys. Fluids B 3, 627 (1991)] on ion‐temperature‐gradient modes in toroidal geometry is extended to noncircular cross sections to examine the scaling with the elongation κ. The growth rate, wave numbers, and stability thresholds are calculated for a flat density profile characteristic of H‐mode operation, and a mixing‐length estimate of the ion thermal diffusivity χi is calculated. It is found that in the plasma core, growth rates decrease as the central elongation κ increases, due to finite‐Larmor‐radius effects. The calculated χi is approximately of the form χi=DTi3/2[(LTi)c−LTi] where D and (LTi)c depend on τ=(Te/Ti) and geometry, and LTi=‖Ti/∇Ti‖. Preliminary evidence indicates fair agreement with experimental data near the plasma edge, where LTi≪ (LTi)c, but the fit is poorer in the core where LTi∼(LTi)c and the theoretical χi is very sensitive to the accuracy in calculating (LTi)c. |
| Databáze: | OpenAIRE |
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