Investigations into auroral electron cycylotron radio emission processes by laboratory experiments and numerical simulations

Electron cyclotron radio emissions, known as Auroral Kilometric Radiation (AKR) originate in the X-mode from regions of locally depleted plasma in the terrestrial polar magnetosphere. A laboratory experiment was constructed to study the emission mechanism of AKR scaled to microwave frequencies [1-2]. 3D PiC simulations of the experiment were conducted to study resonant energy transfer with nonazimuthally symmetric modes of the bounding radiation structure. These 3D simulations show the backward-wave resonance to be resilient to Doppler broadening of the beamwave coupling [3]. It would suggest that the auroral process may emit with backward-wave coupling giving a spectral downshift and thus avoiding the upper hybrid stopband [4].