Possible wave modes of wideband nonthermal continuum radiation in its source region

0357107 - ÚFA 2011 RIV US eng J - Journal Article
Grimald, S. - Santolík, Ondřej
Possible wave modes of wideband nonthermal continuum radiation in its source region.
Journal of Geophysical Research. Roč. 115, - (2010), A06209/1-A06209/8. ISSN 0148-0227
R&D Projects: GA ČR GA205/09/1253; GA MŠMT ME09107
Grant - others:ESA(XE) PECS98025
Institutional research plan: CEZ:AV0Z30420517
Keywords : nonthermal continuum * NTC * wave modes
Subject RIV: BL - Plasma and Gas Discharge Physics
Impact factor: 3.303, year: 2010

Nonthermal continuum (NTC) electromagnetic radiation is generated within the Earth’s magnetosphere and radiated to the outer space. We present cases of a specific type of NTC, which appears as multiple wide bands on the spectrograms recorded by the Cluster spacecraft just outside the plasmapause. This NTC comes from several sources located in the plasmapause density gradient where the local upper hybrid frequency is close to the harmonics of the electron cyclotron frequency. Analysis of one of these events at the eighth harmonic frequency indicates that, in the vicinity of the source, the electric field fluctuations are polarized in the plane perpendicular to the magnetic field line. Hot-plasma dispersion relation based on the measured electron distribution shows that the observed polarization excludes the presence the Langmuir mode and the ordinary mode.
Permanent Link: http://hdl.handle.net/11104/0195454