تقرير
The role of magnetic islands in modifying long range temporal correlations of density fluctuations and local heat transport
| العنوان: | The role of magnetic islands in modifying long range temporal correlations of density fluctuations and local heat transport |
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| المؤلفون: | van Milligen, B. Ph., Estrada, T., Garcia, L., Bruna, D. Lopez, Carreras, B. A., Xu, Y., Ochando, M., Hidalgo, C., Reynolds-Barredo, J. M., Fraguas, A. Lopez |
| المصدر: | Nucl. Fusion, 56, 1 (2016) 016013 |
| سنة النشر: | 2015 |
| المجموعة: | Physics (Other) |
| مصطلحات موضوعية: | Physics - Plasma Physics |
| الوصف: | This work explores the relation between magnetic islands, long range temporal correlations and heat transport. A low order rational surface ($\iota/2\pi = 3/2$) was purposely scanned outward through an Electron Cyclotron Resonance Heated (ECRH) plasma in the TJ-II stellarator. Density turbulence and the poloidal flow velocity (or radial electric field) were characterized using a two channel Doppler Reflectometer. Simultaneously, the ECRH power was modulated to characterize heat transport, using measurements from a 12 channel Electron Cyclotron Emission diagnostic. A systematic variation of the poloidal velocity was found to be associated with the stationary $\iota/2\pi = 3/2$ magnetic island. Inside from the rational surface, the Hurst coefficient, quantifying the nature of long-range correlations, was found to be significantly enhanced. Simultaneously, heat transport was enhanced as well, establishing a clear link between density fluctuations and anomalous heat transport. The variation of the Hurst coefficient was consistent with a magnetohydrodynamic turbulence simulation. Comment: 38 pages, 18 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1088/0029-5515/56/1/016013 |
| URL الوصول: | http://arxiv.org/abs/1506.06890 |
| رقم الأكسشن: | edsarx.1506.06890 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1088/0029-5515/56/1/016013 |
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