Investigation of Temperature Screening of Neoclassical Impurity Transport in High Rotational Tokamak Plasmas

A recent study [1] shows that the temperature screening of impurity neoclassical transport depends on the impurity collisionality non-monotonically, which is verified numerically and analytically. This tendency is determined dominantly by the impurity particle flux component proportional to the main ion temperature gradient, and the component coefficient is sensitive to inverse aspect ratio [1] and toroidal rotation speed [2]. The analytical models of the coefficient of the main ion temperature gradient were derived under the assumptions such as low rotational plasmas [1, 3] or small inverse aspect ratio [3]. In this work, we investigate the analytical model for non-monotonic dependency of the coefficient on the collisionality by extending the limit to the high-rotational plasmas and compare the results with NEO [3-4] simulations. The neoclassical impurity transport model is applied to interpret the KSTAR Tungsten impurity measurements [2].