Excitation of a magnetospheric maser through modification of the Earth’s ionosphere by high-power HF radio emission from a ground-based transmitter

Precipitation of Energetic Electrons from the Earth’s Radiation Belt Stimulated by High-Power HF Radio Waves for Modification of the Midlatitude Ionosphere

“…The first results directly confirming the possibility to stimulate the energetic electron precipitations in the midlatitude ionosphere were obtained at the Sura facility in the experiment of May 12, 2008, in which it was found that the formation of a duct at the altitudes of the outer ionosphere (h ≈ 660 km) led to a severalfold enhancement of the flux of energetic electrons with energies E ≈ 100 keV inside the duct. Based on these results, it was concluded in [7] that the observed electron precipitations are due to controlled excitation of the magnetospheric maser by using high-power radio waves from a ground-based short-wave transmitter to form an artificial waveguide channel -a duct with increased plasma density [5,8,9]. The subsequent analysis of the whole volume of collected experimental data obtained during the DEMETER mission showed the presence of precipitations in many other cases, as well, which stimulated a more detailed study of the nature of the phenomena observed.…”

“…The measurements were taken 19 days after the start of geomagnetic disturbances. Note that the measurement results in this particular session were considered in [7], where it was concluded that more intense precipitations of energetic electrons inside the duct, which were observed during the Sura radiation, are determined by the excitation of a magnetospheric maser. Based on the obtained data it became clear that not only the energetic electron precipitations inside the duct are artificial, but also precipitations south and north of the duct (only at a distance of 1070 km along the satellite orbit, almost along the meridian) were also stimulated due to the ionosphere modification by high-power HF radio waves.…”

Aperiodic and wave disturbances in the ionosphere: the results of vertical sounding»

“…This mechanism was proposed in [107,173]. It is important to note that the eruption of electrons with energies ε e = 102 keV stimulated by the radio transmission of the "Sura" stand, was observed by DEMETER satellite [179,180].…”

Past, Present and Future of Active Radio Frequency Experiments in Space

“…One of the significant nonlocal effects of HF O-mode heating is the creation of O + ion outflows observed by the EISCAT UHF ISR, DMSP spacecraft, and HAARP Digisonde sky map technique [Rietveld et al, 2003;Milikh et al, 2010a;Blagoveshchenskaya et al, 2011;Kosch et al, 2010; 2014; Vartanyan et al, 2012] along with plasma density enhancements (artificial ducts) in the topside ionosphere measured onboard the DEMETER and DMSP spacecraft [Frolov et al, 2016;Milikh et al, 2008a;Rapoport et al, 2010;Markov et al, 2010;Vartanyan et al, 2012]. During satellite overflight experiments, the heating facility was usually turned on 10-20 min before the predicted satellite crossing the facility magnetic flux tube at the closest distance ΔRc from the center (MZ).…”

“…Albeit similar modulations of much lower amplitudes are also observed outside the duct, it seems likely to infer from these modulations that field-aligned filaments of ~20 km transverse scale-size are generated in the heated volume. It is worth of note that in several SURA-DEMETER experiments coincident with injections of powerful VLF electromagnetic waves from the nearby VLF transmitter and artificial ducts served as a waveguide for VLF whistler waves [Markov et al, 2010;Rapoport et al, 2010].…”