A model for the effects of temperature gradients and magnetic shear on the drift wave monopole solutions

A model that incorporates both the effects of temperature gradients and magnetic shear on the drift wave monopole solutions is analyzed. In the case where the former effect is treated improperly and the latter is neglected, there exist exact monopole solutions, which is equivalent to the existence of a point spectrum for a nonlinear eigenvalue problem. When both the effects are included, this spectrum becomes a banded continuous spectrum. An eigenvalue of this spectrum is associated with a localized vortex structure that undulates in space about a fixed level, eventually matching to a radiative ion acoustic tail. A novel separatrix crossing technique is used to investigate this problem. (author)