Extended theory of main ion and impurity rotation and bootstrap current in a shear layer

In this paper, standard neoclassical theory has been extended into the shear layer. Main ion and impurity ion rotation velocity and bootstrap current within shear layer in H-mode are discussed. Inside the H-mode shear layer, standard neoclassical theory is not valid since the ion poloidal gyroradius becomes comparable to pressure gradient and electric field gradient scale length. We present modified expressions of impurity flows and bootstrap current in a shear layer neglecting ion temperature gradient. Comparisons with DIII-D measurements are also discussed. (author)