Contribution of higher pitch angles in sideband generation

Abstract

Non-linear cyclotron resonance between energetic electrons and Siple (Antarctica) transmitted VLF signals in the magnetosphere is considered as the cause of sideband generation observed in received spectrograms recorded at ground station situated at Roberval (Canada). The role of higher pitch angles (> 45°) in producing observed average spacing (30-60 Hz) is studied. It is shown that observed average spacing can only be produced if interacting electrons pitch angle (⍺) is greater than 45° and spacing increases with increase in pitch angle and wave magnetic amplitude as well.