Resistive drift modes in general geometry

A global approach for calculating resistive drift modes is developed, which does not use a ballooning formalism but solves the three-dimensional eigen value problem directly. The drift-wave model is based on linearized two-flu id equations with cold ions and electrostatic perturbations. For an axisymm etric model equilibrium results from the global approach are compared to th ose following from a ballooning approximation. For consistent equilibria th e global approach is used to investigate the structure of resistive drift m odes in tokamak configurations with positive/negative shear as well as in s traight and toroidal l = 2-stellarator configurations. (C) 2001 American In stitute of Physics.