Spectroscopic study of edge poloidal rotation and radial electric fields in the DIII‐D tokamak (invited)
| Autor: | R. P. Seraydarian, P. Gohil, K. H. Burrell, R. J. Groebner |
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| Rok vydání: | 1990 |
| Předmět: | |
| Zdroj: | Review of Scientific Instruments. 61:2920-2925 |
| ISSN: | 1089-7623 0034-6748 |
| Popis: | Doppler‐shift spectroscopy has shown that finite values of poloidal rotation velocity vθ and of radial electric field Er exist at the edge of a tokamak plasma and that dramatic increases occur in these parameters at an L‐H transition. Er is negative in the L mode and becomes more negative in the H mode; vθ increases in magnitude at the transition. In addition, the radial gradients (shear) of vθ and Er are large and these gradients also increase at the L‐H transition. These results are based on measurements of Doppler shifts of light emitted by He II ions, located in a region about 1–3 cm inside the separatrix. These observations have been made with horizontally viewing and vertically viewing spectrometer systems on the DIII‐D tokamak. The nearly orthogonal views of these systems are used to determine the plasma’s flow velocity in terms of the orthogonal sets vθ and vφ or of v⊥ and v∥. Knowledge of v⊥ is used to calculate Er from the force balance equation for a single ion species. The existing results imp... |
| Databáze: | OpenAIRE |
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