Electrostatic ion cyclotron waves in barium injection experiments in space

Abstract

Electrostatic ion cyclotron waves are investigated in a charge-generated barium-shaped plasma directed parallel to the earth’s magnetic field. The barium plasma is generated as a result of a barium shape charge release in the upper F₂ region of the ionosphere undergoing photoionization, Using a differential velocity distribution given by Stenbaek-Nielsen et al., [1984], this situation has been modeled based on the condition of collisionless plasma. The instabilities were studied for cases with and without an ambient oxygen ion background. It was concluded that fast ionization in excess of photoionization due to the excitation of electrons by electrostatic ion cyclotron waves was not feasible for the ejection directed along the earth’s magnetic field nor would there be any contribution to Alfven’s critical velocity mechanism if the injection was directed perpendicular to the magnetic field.