Lower hybrid oscillation

In plasma physics, a lower hybrid oscillation is a longitudinal oscillation of ions and electrons in a magnetized plasma. The direction of propagation must be very nearly perpendicular to the stationary magnetic field, within about √(m_e/m_i) radians. Otherwise the electrons can move along the field lines fast enough to shield the oscillations in potential, in which case an electrostatic ion cyclotron wave results. The frequency of oscillation is