A drift model of interchange instability

Abstract

A set of asymptotic equations is derived, describing the dynamics of the flute mode in a magnetized plasma with cold ions, under a "local" approximation ͑i.e., near a particular point͒. The asymptotic set is then used to calculate the growth rate of interchange instability in the slab model. It is shown that, unlike the magnetohydrodynamic ordering, the drift one allows instability to occur for either sign of the pressure gradient ͑i.e., for both "bad" and "good" curvature of the magnetic field͒. It is also demonstrated that finite beta gives rise to an extra instability that does not exist in the small-beta limit.

Shock waves in Stokes flows down an inclined plate

“…Substituting (13) and (14) into Eqs. (2)-(7) with γ = 0 and linearizing them, we obtaiñ p x =ũ xx +ũ yy ,p y =ṽ xx +ṽ yy ,ũ x +ṽ y = 0, (15) …”