Transport equations and gradient instabilities in a high pressure collisional plasma

A theoretical study is presented of the instability of plasma wth finite ratio of particle to magnetic pressures. The instabilities caused by spatial gradients are considered. They have a characteristic frequency omega approximately=( rho i /a) 2 omega B where rho i =v Ti / omega Bi is the ion Larmor radius, v Ti =T i /m i is the ion thermal velocity, a is the scale length of the plasma inhomogeneity, omega Bi =e i B o /m i c is the ion cyclotron frequency. It is shown that the usual set of transport equations for plasma obtained by the Chapman-Enskog method, are broadly speaking not suitable for investigating instabilities with frequencies of order ( rho i /a) 2 omega B i . A new system of transport equations applicable to this frequency range is obtained. Some new types of instabilities of finite pressure plasma are investigated by means of these transport equations.