The radial electric field in a tokamak with reversed magnetic shear
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States)
- National Institute for Fusion Science, Toki 509-5292 (Japan)
Neoclassical theory with the impurity rotational velocity is used to evaluate the radial electric field, E{sub r}, in a tokamak. The result of using the complete matrix method for the deuterium{endash}carbon plasma is compared with a reduced analytic formula for determining E{sub r} [Ernst {ital et al.}, Phys. Plasmas {bold 5}, 665 (1998)]. The analytic formula is shown to overestimate the E{sub r} magnitude and its gradient. Two transport measures of the effect of the E{sub r} shear are compared for the reversed shear and enhanced reversed shear discharges in Tokamak Fusion Test Reactor [Mazzucato {ital et al.}, Phys. Rev. Lett. {bold 77}, 3145 (1996)]. It is shown that the combined E{sub r} and magnetic shear measure, {Upsilon}{sub s}, from linear stability theory gives a higher correlation with the observed transition between the two discharges than the vorticity measure {omega}{sub s} from E{sub r} shear alone. {copyright} {ital 1999 American Institute of Physics.}
- OSTI ID:
- 338680
- Journal Information:
- Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 6 Vol. 6; ISSN 1070-664X; ISSN PHPAEN
- Country of Publication:
- United States
- Language:
- English
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