Enhancement of neoclassical impurity density up/down asymmetry and Pfirsch-Schluter transport due to the plasma elongation in the tokamak plasmas

The standard neoclassical theory of the impurity transport in tokamak plasma is improved by including the plasma elongation effect. The neoclassical up/down asymmetry of the impurity density is largely enhanced by the plasma elongation and is under-predicted by the neoclassical theory with the circular cross section assumption. Accordingly, the impurity Pfirsch-Schluter neoclassical transport is also enhanced by the plasma elongation.