Dynamics of Plasma Blobs in a Shear Flow
- Centre de Recherches en Physique des Plasmas Association Euratom-Confederation Suisse, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne CH-1015 (Switzerland)
The global dynamic of plasma blobs in a shear flow is investigated in a simple magnetized torus using the spatial Fourier harmonics (k-space) framework. Direct experimental evidence of a linear drift in k space of the density fluctuation energy synchronized with blob events is presented. During this drift, an increase of the fluctuation energy and a production of the kinetic energy associated with blobs are observed. The energy source of the blob is analyzed using an advection-dissipation-type equation that includes blob-flow exchange energy, linear drift in k space, nonlinear processes, and viscous dissipations. We show that blobs tap their energy from the dominant ExB vertical background flow during the linear drift stage. The exchange of energy is unidirectional as there is no evidence that blobs return energy to the flow.
- OSTI ID:
- 21179710
- Journal Information:
- Physical Review Letters, Vol. 101, Issue 11; Other Information: DOI: 10.1103/PhysRevLett.101.115005; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
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