High energetic electrons and electron cyclotron waves and their harmonics in the polar cusp.
Résumé
The most characteristic features of the wave spectra measured in the polar cusp found by Interball 1 and Polar satellites and confirmed by Cluster are the broad band emissions with maxima at the lower hybrid, around electron cyclotron and its harmonics frequencies. Interball 1 and its companion Magion 4 sometimes registered emissions with extremely high intensity in these frequencies ranges. These waves correlate with strong fluxes of high energetic electrons often observed within the polar cusp by Interball 1 and Magion 4 as well as by Polar satellites. Cluster measurements give new insight of these emissions. The observations of electron cyclotron and their harmonics gathered on Magion 4 and Cluster satellites associated with strong fluxes of energetic electrons will be presented. Short discussion of the possible generation mechanism, such as 'fan' instability, will be added.