Radio Frequency Induced and Neoclassical Asymmetries and their Effects on Turbulent Impurity Transport in a Tokamak. Issue 4 (June 2014)

• Record Type: Journal Article
• Authors: Pusztai, I.; Landreman, M.; Mollén, A.; Kazakov, Ye. O.; Fülöp, T.
• Is Part Of: Contributions to plasma physics. Volume 54:Issue 4/6(2014)
• Page Start: 534
• Page End: 542
• Publication Date: 2014-06
• Subjects: Plasma (Ionized gases) -- Periodicals; Electronic journals; 530.44
• DOI: 10.1002/ctpp.201410012
• Languages: English
• ISSNs: 0863-1042

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Poloidal asymmetries in the impurity density can be generated by radio frequency heating in the core and by neoclassical effects in the edge of tokamak plasmas. In a pedestal case study, using global neoclassical simulations we find that finite orbit width effects can generate significant poloidal variation in the electrostatic potential, which varies on a small radial scale. Gyrokinetic modeling shows that these poloidal asymmetries can be strong enough to significantly modify turbulent impurity peaking. In the pedestal the <italic>E</italic> × <italic>B</italic> drift in the radial electric field can give a larger contribution to the poloidal motion of impurities than that of their parallel streaming. Under such circumstances we find that up‐down asymmetries can also affect impurity peaking. (© 2014 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)</p> </abstract>