Aspects of Collisional Diffusion Transverse to a Stable Magnetic Plasma

An autocorrelation function method is given which permits one to treat, in a relatively simple and concise manner, some aspects of transverse diffusion in stable plasmas that are generally omitted or difficult to formulate by other methods. An expression for the transverse diffusion coefficient is thereby obtained which is valid under a wide set of circumstances including non-Maxwellian, but stable, velocity distributions, arbitrary ratio of gyrofrequency to collision frequency, and weakly nongyrotropic velocity distributions. It is also emphasized that the diffusion coefficient is not simply an eigenfunction of the collision operator, and the correction factors are explicitly given for magnetic non-Maxwellian plasmas.