SIMULATIONS OF BEAM EXCITED MINOR SPECIES GYROHARMONICS IN THE PORCUPINE EXPERIMENT.

The porcupine sounding rocket experiment included a spinning daughter payload equipped with a xenon plasma gun that emitted an ion beam nearly transverse to the magnetic field. Wave instruments on the main payload detected electrostatic waves at hydrogen gyroharmonics and at the lower hybrid frequency within the beam. A series of computer simulations was performed to investigate the behavior of a system including a xenon beam, modeled from the rocket experiment, and a background ionosphere plasma of oxygen plus a small concentration of hydrogen. In these one-dimensional simulations, a spatially homogeneous xenon beam is injected perpendicular to the magnetic field and at various angles with respect to the wave propagation vectors.