Istvan Pusztai

TL;DR: In this paper, the effect of poloidal asymmetry of impurities on impurity transport driven by electrostatic turbulence in tokamak plasmas is analyzed, and it is shown that in the presence of in-out asymmetric impurity populations the zero-flux impurity density gradient is significantly reduced.

TL;DR: In this article, the evolution of the runaway distribution is well described by an initial hot-tail seed population, which is accelerated to energies between 25-50 MeV during the current quench, together with an avalanche runaway tail which has an exponentially decreasing energy spectrum.

TL;DR: In this article, a radially global $\delta f$ continuum code was proposed to generalize neoclassical calculations to allow stronger gradients, which is time independent and requires only the solution of a single sparse linear system.

TL;DR: In this paper, the authors generalize earlier analytic stellarator calculations of the neoclassical radial impurity flux in the mixed-collisionality regime to include the effect of such flux-surface variations, and find that only in the homogeneous density case is the transport of highly collisional impurities (in the Pfirsch-Schlhter regime) independent of the radial electric field.