Evolution of electron phase-space holes in 3D

Electron phase-space holes are regions of depleted electron density commonl y generated during the nonlinear stage of the two-stream instability Recent ly, bipolar electric field structures - a signature of electron holes have been identified in the acceleration region of the auroral ionosphere. This paper compares the evolution of electron holes in 2-D and 3-D using massive ly-parallel PIC simulations. In 2-D, the holes decay after hundreds of plas ma periods while emitting electrostatic whistler waves. In the 3-D simulati ons, electron holes also go unstable and generate whistlers but, due to phy sical processes not present in 2-D energy flows out of the whistlers and in to highly perpendicular lower hybrid modes. As a result of this difference, 3-D holes do not decay as far as 2-D holes. The differences between 2-D an d 3-D evolution may have important. implications for hole longevity and wav e generation in the auroral ionosphere.