Ideal quasimodes reviewed in resistive magnetohydrodynamics

The characteristics of so-called ideal quasimodes'' or collective modes'' are investigated in the framework of linearized, compressible and resistive magnetohydrodynamics. It is shown that ideal quasimodes correspond to weakly damped eigenmodes of the resistive-MHD differential operator. The damping of these modes becomes independent of the plasma resistivity in the limit of vanishing {eta}. Hence, for the first time in the range of the Alfven continuum, resistive eigenmodes have been found that converge to their ideal-MHD transforms as {eta}{r arrow}0.