Turbulence Interaction with Driven Transport Barriers in the Scrape‐Off Layer of Tokamaks. Issue 6 (12th July 2016)

• Record Type: Journal Article
• Authors: Nace, N.; Perin, M.; Tamain, P.; Ciraolo, G.; Baudoin, C.; Futtersack, R.; Ghendrih, Ph.; Norscini, C.
• Is Part Of: Contributions to plasma physics. Volume 56:Issue 6/8(2016)
• Page Start: 581
• Page End: 586
• Publication Date: 2016-07-12
• Subjects: Tokamak -- Scrape‐Off Layer -- turbulence -- transport barrier -- simulations; Plasma (Ionized gases) -- Periodicals; Electronic journals; 530.44
• DOI: 10.1002/ctpp.201610052
• Languages: English
• ISSNs: 0863-1042

Abstract

Abstract: Two mechanisms able to generate a transport barrier by the stabilization of turbulence are analysed: the radial shear of the E × B velocity and the radial gradient of this shear. These two mechanisms are artificially forced in dedicated 2D non‐linear fluid simulations to study their impact on turbulence in the Scrape‐Off Layer. Generated barriers are characterized by their turbulence stopping capability and a key parameter, the barrier efficiency, is pointed out. The first two moments of this criterion can be studied to quantify the global efficiency, shape and width of the barrier as well as its intermittency. It is found that both mechanisms can drive intermittent or stable barriers but the radial shear mechanism generates stronger relaxation events. Small scale structures are damped by the E × B velocity shear while the radial shear gradient acts mainly on large scales. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)