Progress toward laboratory measurements of the acceleration of auroral electrons by Alfven waves*

A nonlinear interaction between Alfven waves and electrons is believed to be responsible for a significant fraction of auroral electron acceleration. Experiments at UCLA’s LAPD are designed to measure this wave-particle interaction for the first time. Alfven waves are launched while simultaneously measuring changes to the electron velocity distribution. Distribution function measurements are performed using a high-precision technique called wave absorption. Wave absorption measurements have isolated oscillations of the electron distribution associated with the Alfven wave. A linear kinetic model has been developed that describes the measured electron oscillations. The model includes the nonideal effects of collisions and finite experimental length and was used to design the most recent set of experiments. Current work focuses on using the field-particle correlation technique with linear measurements to explore the net transfer of energy between Alfven waves and electrons.