Finite ion temperature effects on scrape-off layer turbulence
| Autor: | Joaquim Loizu, Paolo Ricci, Federico David Halpern, Annamaria Mosetto, Sébastien Jolliet |
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| Rok vydání: | 2015 |
| Předmět: |
Physics
Resistive ballooning mode Resistive touchscreen Tokamak Condensed matter physics Wave propagation Turbulence CRPP_EDGE Mechanics Condensed Matter Physics 01 natural sciences Instability Ballooning 010305 fluids & plasmas law.invention Computer Science::Emerging Technologies Physics::Plasma Physics law 0103 physical sciences Electron temperature 010306 general physics |
| Zdroj: | Physics of Plasmas PHYSICS OF PLASMAS |
| ISSN: | 1089-7674 1070-664X |
| DOI: | 10.1063/1.4904300 |
| Popis: | Ion temperature has been measured to be of the same order, or higher, than the electron temperature in the scrape-off layer (SOL) of tokamak machines, questioning its importance in determining the SOL turbulent dynamics. Here, we present a detailed analysis of finite ion temperature effects on the linear SOL instabilities, such as the resistive and inertial branches of drift waves and ballooning modes, and a discussion of the properties of the ion temperature gradient (ITG) instability in the SOL, identifying the gi 1⁄4 Ln=LTi threshold necessary to drive the mode unstable. The non-linear analysis of the SOL turbulent regimes by means of the gradient removal theory is performed, revealing that the ITG plays a negligible role in limited SOL discharges, since the ion temperature gradient is generally below the threshold for driving the mode unstable. It follows that the resistive ballooning mode is the prevailing turbulence regime for typical limited SOL parameters. The theoretical estimates are confirmed by non-linear flux-driven simulations of SOL plasma dynamics. |
| Databáze: | OpenAIRE |
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