Collisional drift waves in 3-dimensional plasmas

A 3-field model describing collisional drift waves in arbitrary 3-dimensional plasma geometry is derived. Linear growth rates for the perturbed plasma density, electrostatic potential and electron temperature are obtained by solving the 3-field model as an initial-value problem. The slab geometry case is solved analytically. Numerical solutions for a pressureless tokamak configuration are presented; the influence of the global magnetic shear on the linear growth rates is discussed. The model is then considered for a shearless stellarator configuration; The local attributes of the confining magnetic field strongly influence both the temporal (growth rate) and spatial (mode extent) behaviors of the collisional drift waves.