Linear theory and measurements of electron oscillations in an inertial Alfvén wave

The physics of the aurora is one of the foremost unsolved problems of space physics. The mechanisms responsible for accelerating electrons that precipitate onto the ionosphere are not fully understood. For more than three decades, particle interactions with inertial Alfven waves have been proposed as a possible means for accelerating electrons and generating auroras. Inertial Alfven waves have an electric field aligned with the background magnetic field that is expected to cause electron oscillations as well as electron acceleration. Due to the limitations of spacecraft conjunction studies and other multi-spacecraft approaches, it is unlikely that it will ever be possible, through spacecraft observations alone, to confirm definitively these fundamental properties of the inertial Alfven wave by making simultaneous measurements of both the perturbed electron distribution function and the Alfven wave responsible for the perturbations. In this laboratory experiment, the suprathermal tails of the reduced elect...