Back to Search Start Over

Direct Observation of Electron Distributions inside Millisecond Duration Electron Holes.

Authors :
Mozer FS
Agapitov OV
Giles B
Vasko I
Source :
Physical review letters [Phys Rev Lett] 2018 Sep 28; Vol. 121 (13), pp. 135102.
Publication Year :
2018

Abstract

Despite the importance of millisecond duration spatial structures [chorus wave nonlinearity or time domain structures (TDS)] to plasma dynamics, there have been no direct observations of the generation and interaction of these waves and TDS with electrons at the millisecond timescale required for their understanding. Through superposition of 0.195 ms Magnetospheric Multiscale Satellite electron measurements inside 37 superposed, millisecond duration electron holes, the first observations of electron spectra and pitch angle distributions on a submillisecond timescale have been obtained. They show that keV electrons inside the superposed electron hole are accelerated by several hundred volts and that the spectrum of electrons inside the electron hole contain several maxima and minima that are explained by a model of electron energy changes on entering the holes. We report the first observation of trapped electrons inside the TDS, in accordance with the theoretical requirement that such electrons must be present in order to form the phase space holes. Mechanisms of electron acceleration by electron holes (through perpendicular energy gain as the TDS moves into a converging magnetic field) and scattering (due to the perpendicular electric field) are discussed.

Details

Language :
English
ISSN :
1079-7114
Volume :
121
Issue :
13
Database :
MEDLINE
Journal :
Physical review letters
Publication Type :
Academic Journal
Accession number :
30312045
Full Text :
https://doi.org/10.1103/PhysRevLett.121.135102