A KINETIC-THEORY FOR THE DRIFT-KINK INSTABILITY

We have developed a linear two-dimensional kinetic theory, which is mo tivated by recent results for the drift-kink instability. The theory p redicts plasma instability for large values of ion-electron temperatur e ratios. T-i/T-e, moderate drift speeds, and large ion-electron mass ratios, m(i)/m(e), corresponding to conditions in the near-Earth regio n of the magnetotail neutral sheet. The growth rate predicted by the t heory is in good agreement with nonlinear plasma simulations (but the mode structure is not), including linear growth rates obtained with an implicit, electromagnetic simulation with realistic ion-electron mass ratio.