Impurity effects on ion-drift-wave eigenmodes in a sheared magnetic field

Abstract
The stability of ion‐drift‐wave eigenmodes in a slab geometry with a sheared magnetic field is investigated. It is found that in contrast to the case of universal and dissipative electron‐drift‐wave eigenmodes, unstable impurity‐driven normal modes can appear if specific conditions are satisfied. In addition, the influence of impurities on unstable ion‐temperature‐gradient‐driven drift eigenmodes is also studied. It is found that, if their density profile is inwardly peaked, the impurities can exert a strong stabilizing influence on these modes.