Direct observation of sub-millisecond electron distributions inside nonlinear waves and structures in the earth’s magnetosphere*

In spite of the importance of millisecond duration spatial structures (chorus wave non-linearities or time domain structures) to plasma dynamics, there have been no direct observations in space of the generation and interaction of these waves and TDS with electrons on the sub-millisecond time scale required for understanding the nonlinear physics. Through superposition of 0.195 millisecond Magnetospheric Multiscale Satellite (MMS) electron measurements, the first observations of electron spectra and pitch angle distributions in electron phase space holes and non-linear whistlers have been obtained.  These observations are described and compared with theory.