Showing 1 - 4 of 4 Journals Results
2019
UKAEA-CCFE-PR(19)53
S. Buller A. Mollén S.L. Newton H.M. Smith I. Pusztai
In toroidal magnetic confinement devices, such as tokamaks and stellarators, neoclassical transport is usually an order of magnitude larger than its classical counterpart. However, when a high-collisionality species is present in an stellarator optimized for low Pfirsch-Schlüter current, its classical transport can be comparable to the neoclassica…
Preprint Published2018
UKAEA-CCFE-PR(19)04
S. Buller H.M. Smith A. Mollen S.L. Newton I. Pusztai
Avoiding impurity accumulation is a requirement for steady-state stellarator operation. The accumulation of impurities can be heavily affected by variations in their density on the flux-surface. Using recently derived semi-analytic expressions for the transport of a collisional impurity species with high-Z and flux-surface density-variation in t…
Preprint Published2018
UKAEA-CCFE-PR(18)44
S. Buller H.M. Smith P. Helander A. Mollén S.L. Newton I. Pusztai
High-Z impurities in magnetic confinement devices are prone to develop density variations on the fluux-surface, which can significantly affect their transport. In this paper, we generalize earlier analytic stellarator calculations of the neoclassical radial impurity flux in the mixed-collisionality regime (collisional impurity and low-collisionalit…
Preprint Published2016
CCFE-PR(16)63