Geometrical Effects in Plasma Stability and Dynamics of Coherent Structures in the Divertor

The effects of the strong X‐point magnetic shear, of the orientation of the divertor legs with respect to the major axis, and of the tilt of the divertor plates with respect to the poloidal field on plasma dynamics in the divertor region have been studied. The linear stability analysis of flute and resistive ballooning modes is presented for the X‐point geometry, with emphasis on the private flux region. The dynamics of isolated plasma filaments (“blobs”) passing near the X point is described. In both cases the correct accounting for the geometry turns out to be critically important. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)