DIII-D RESEARCH OPPORTUNITIES FORUM FOR THE 2008 EXPERIMENTAL CAMPAIGN
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| Title | 344: Search for the critical ExB velocity shear for ITG and ETG | ||
| Name: | Lei Zeng ( |
Affiliation: | University of California, Los Angeles |
| Research Area: | Rotation Physics | Presentation time: | Not requested | Co-Author(s): | UCLA group |
| Description: | The goal of this experiment is to search for the critical ExB velocity shear for ITG and ETG turbulences. | ||
| Experimental Approach/Plan: | Use CER and Doppler reflectometer to measure Er, in order to get ExB velocity shear. Use FIR to measure low-k , intermediate-k turbulence, and back scattering for high k. For the ITB plasma (maybe QDB operation), scan ExB velocity shear in ITB by changing the NBI and measure the turbulence associated and compare to simulations. | ||
| Background: | The results from many devices have observed short-k turbulence reduces and ExB shear increases after the formation of ITB. Theoretical simulation shows the critical ExB velocity shear is smaller than vti/Ln for suppression of ITG and short wavelength ion mode (SWITG), however, the critical shear for ETG is much larger [PoP, vol. 11, p. 3053]. In DIII-D, it is possible to search for the critical ExB velocity shear for ITG and ETG modes experimentally, since we have a verity of turbulence diagnostics covering a large range of k space, counter beams may provide velocity shear control. | ||
| Resource Requirements: | -- | ||
| Diagnostic Requirements: | -- | ||
| Analysis Requirements: | -- | ||
| Other Requirements: | -- | ||
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