Origin of ion-cyclotron turbulence in the downward Birkeland current region

Autor:	Neil Grossbard, Eric J. Lund, J. R. Jasperse, B. Basu
Rok vydání:	2011
Předmět:	Physics Turbulence Magnetosphere Plasma Electron Condensed Matter Physics Stability (probability) Computational physics Distribution function Physics::Plasma Physics Dispersion relation Physics::Space Physics Dispersion (optics) Atomic physics
Zdroj:	Physics of Plasmas. 18:022901
ISSN:	1089-7674 1070-664X
DOI:	10.1063/1.3552156
Popis:	Linear stability analysis of the electron velocity distributions, which are observed in the FAST satellite measurements in the downward Birkeland current region of the magnetosphere, is presented. The satellite-measured particle (electrons and protons) velocity distributions are fitted with analytic functions and the dispersion relation is derived in terms of the plasma dispersion functions associated with those distribution functions. Numerical solutions of the dispersion relation show that the bump-on-tail structure of the electron velocity distribution can excite electrostatic ion-cyclotron instabilities by the Landau resonance mechanism. Nonlinear evolution of these instabilities may explain the observed electrostatic ion-cyclotron turbulence in the Birkeland current region. Excitation of other types of instabilities by the fitted electron velocity distributions and their relevance are also discussed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c338b503be6a3d13f94ca0f7cef5442f https://doi.org/10.1063/1.3552156 Zobrazit plný text záznamu