The transport of high-Z impurities resulting from Compton and induced scattering by drift waves is found to be comparable in magnitude with base ion and electron transport when the fluctuation spectrum is obtained from a recent theory of drift turbulence. The anomalous frictional flux is marginally subdominant whilst the diffusion flux is enhanced over the neoclassical value by a numerical factor which (i) agrees quantitatively with the results of impurity injection experiments, (ii) decreases with increasing base ion atomic mass, and (iii) is independent of the impurity-charge-to-mass ratio. The theory further predicts a dramatic increase in anomaly, also in agreement with experimental results, when the growth rate is enhanced during the heat pulse released by the sawtooth relaxations of the core.
Drift wave transport and origin of the disruption phenomenon – a theoretical model