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Comparative study of the energetic electrons registered together with the broad band emissions in different regions of the ionosphere

Błęcki Jan, Wronowski Roman, Słomiński Jan, Savin Sergey, Iwański Rafał, Haagmans Roger

Artificial Satellites : Journal of Planetary Geodesy

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2020

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Vol. 55, No. 4

130--149

EN

ELF/VLF waves have been registered in the outer polar cusps simultaneously with high energy electrons fluxes by the satellites Magion 4 (subsatellite to Interball 1), Polar and CLUSTER. Further, we discuss similar observations in the different regions of the ionosphere, where DEMETER registered energetic electrons. The DEMETER satellite operating on the nearly polar orbit at the altitude 650 km crossed different regions in the ionosphere. Registrations of ELF/VLF/HF waves together with the energetic electrons in the polar cusp, in the ionospheric trough and over thunderstorm areas are presented in this paper. The three satellites of ESA’s Swarm mission provide additional information on the ELF waves in the mentioned areas together with electron density and temperature. A brief discussion of the generation of these emissions by the so-called “fan instability” (FI) and beam instability is presented.

2

HAARP – unikalna stacja do badań geofizycznych

Gołkowski Marek

Przegląd Geofizyczny

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2019

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Z. 3-4

287--302

PL

W artykule zaprezentowano informacje o amerykańskiej stacji HAARP na Alasce i opisano główne eksperymenty tam przeprowadzone. Stacja jest unikalna, bo posiada dużą moc promieniowania w wysokich częstotliwościach w pasmie HF (2,75-9 MHz), co pozwala na ciekawe badania nad zjawiskami w jonosferze, jak i w magnetosferze. W ostatnich latach stacja przeszła pod zarząd University of Alaska i jest dostępna dla naukowców z całego świata.

EN

We present details of the American geophysical research facility in Alaska known as HAARP and summarize the main experiments that have been carried out therein. The facility is unique due to the high power available for radiation in the HF band (2.75-9 MHz), which enables the investigation of processes in the ionosphere and magnetosphere. In the last few years the facility has come under the administration of the University of Alaska and is now open to international researchers.

3

Causality violation in analysis of Hall thruster plasma instabilities

Peradzyński Z., Barral S., Makowski K., Dudeck M.

Journal of Technical Physics

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2008

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Vol. 49, no 3-4

315-327

EN

Using the fluid equations of Hall thruster plasma we analyze the influence of the electron energy balance on the stability of ion sound modes. For sufficiently low frequencies (ω < 5 • 106^6 s-1 in the case of SPT-100) the gains and losses in the source term are approximately equal, thus the temperature can be in principle determined in terms of other dependent variables. This permits one to reduce the number of equations by one. It appears however, that the new system can have in some regions complex characteristics. This in turn implies instability of certain modes with frequencies lower than the critical frequency.