Studies of instability and transport in sheared-slab plasmas with very weak magnetic shear
- Southwestern Institute of Physics, Chengdu, Peoples Republic of (China)
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712-1060 (United States)
Ion temperature gradient (ITG or {eta}{sub i}) driven microinstabilities are studied, using kinetic theory, for tokamak plasmas with very weak (positive or negative) magnetic shear (VWS). The gradient of magnetic shear as well as the effects of parallel and perpendicular velocity shear (v{sub {parallel}}{sup {prime}} and v{sub E}{sup {prime}}) are included in the defining equations. Two eigenmodes: the double (D) and the global (G) are found to coexist. Parametric dependence of these instabilities, and of the corresponding quasilinear transport is systematically analyzed. It is shown that, in VWS plasmas, a parallel velocity shear (PVS) may stabilize or destabilize the modes, depending on the individual as well as the relative signs of PVS and of the gradient of magnetic shear. The quasilinear transport induced by the instabilities may be significantly reduced with PVS in VWS plasmas. The v{sub E}{sup {prime}} values required to completely suppress the instabilities are much lower in VWS plasmas than they are in normal plasmas. Possible correlations with tokamak experiments are discussed. {copyright} {ital 1997 American Institute of Physics.}
- Research Organization:
- Univesity of Texas
- DOE Contract Number:
- FG03-96ER54346
- OSTI ID:
- 538478
- Journal Information:
- Physics of Plasmas, Vol. 4, Issue 9; Other Information: PBD: Sep 1997
- Country of Publication:
- United States
- Language:
- English
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