Multifaceted asymmetric radiation from the edge (MARFE’s): A general magnetohydrodynamic study in a one‐dimensional tokamak model

Multifaceted asymmetric radiation from the edge (MARFE) is studied as a radiative thermal instability in a one‐dimensional (1‐D) cylindrical equilibrium model. In order to get a global idea of the MARFE onset, a linear analysis is performed, using a full set of magnetohydrodynamic (MHD) equations. It is found that the onset of the MARFE is accompanied by perturbations of pressure and magnetic field. These characteristics seem especially important in case the MARFE leads to a disruption and rational surfaces are affected. The experimentally observed relation between critical density and plasma current [Nucl. Fusion 24, 977 (1984)] is studied. The particular role of perpendicular thermal conduction is considered separately. Correspondence with experimentally observed behavior, like toroidal symmetry and poloidal asymmetry, is discussed.