Electrostatic ion cyclotron electron drift instability

The ion cyclotron electron drift instability is studied using the linear Vlasov dispersion relation for electrostatic instabilities. The sources of free energy are density, temperature and magnetic field gradients across and a current parallel to a unidirectional magnetic field. Propagation is in the plane defined by the drift velocity and the magnetic field. This instability, which is driven by the electron drifts and undergoes ion cyclotron damping, propagates at the ion cyclotron frequency, but at wavelengths much shorter than the ion gyroradius. Although its growth rates are small compared with an ion gyrofrequency, the instability is favored by increasing T e /T i , and it becomes competetive with the ion cyclotron ion drift instability at T e ⩾4T i .