Effect of dissipation due to firehose instability on perturbation half-jet flow of a collisionless plasma

The effects of dissipation due to a week firehose instability on steady planar flow of a collisionless plasma are investigated on the basis of the quasi-linear fluid equations. Dissipation terms remain non-linear even within the perturbation theory, and their effects tend to resemble relaxation effects in an ordinary reacting gas rather than ordinary viscous dissipation. As an example, a steady half-jet flow with aligned magnetic field is considered. It is found that the disturbed field decays within a finite distance for some upstream conditions, but grows without limit for others.