In:
Nuclear Fusion, IOP Publishing, Vol. 49, No. 4 ( 2009-04-01), p. 045001-
Abstract:
We calculate two indicators for neoclassical and anomalous transport in the low collisional regime, effective helical ripple ε eff and zonal flow response , in an L = 2 heliotron with various shapes of the outermost flux surface. The ε eff has a minimum as a function of a parameter representing plasma column twisting, δ b . The time average of the damped zonal flow, , shows a similar dependence on δ b . We can thus find the optimum configuration for both these indicators in an arbitrary L = 2 heliotron, by choosing the optimum value of δ b , together with inherent toroidicity and main helicity of the outermost flux surface. The existence of the optimum is due to the most effective cancellation of the radial drifts of the particles trapped in each helical ripple, rather than the magnetic field symmetry in a whole surface.
Type of Medium:
Online Resource
ISSN:
0029-5515
,
1741-4326
DOI:
10.1088/0029-5515/49/4/045001
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
2009
detail.hit.zdb_id:
2104963-4
detail.hit.zdb_id:
2037980-8
