Temperature gradient drive ion acoustic instability

The stability of ion acoustic waves propagating in a magnetized plasma containing an electron temperature gradient is investigated. The dispersion relation is solved numerically for various electron-ion temperature ratios and electron temperature gradient drift velocities. Earlier predictions, based on analytic calculations for small temperature ratios and drift velocities, are confirmed and some new results are presented. In particular, it is shown that a temperature gradient is a more effective destabilizing agent than a simple drift between ions and electrons. Dispersion plots and neutral stability curves are given.