4 research outputs found
Alfven Wave Generation by means of High Orbital Injection of Barium Cloud in Magnetosphere
An analysis of the Alfven wave generation associated with the barium vapor
release at altitudes ~ 5.2 Earth's radii (ER) in the magnetosphere is
presented. Such injections were executed in G-8 and G-10 experiments of the
Combined Radiation and Radiation Effects Satellite (CRRES) mission. It is shown
that the generation of Alfven waves is possible during the total time of plasma
expansion. The maximum intensity of these waves corresponds to the time of
complete retardation of the diamagnetic cavity created by the expansion of
plasma cloud. The Alfven wave exhibits a form of an impulse with an effective
frequency ~ 0.03-0.05 Hz. Due to the background conditions and wave frequency,
the wave mainly oscillates along the geomagnetic field between the mirror
reflection points situated at ~ 0.7 ER. The wave amplitude is sufficient to the
generation of plasma instabilities and longitudinal electric field, and to an
increase in the longitudinal energy of electrons to ~ 1 keV. These processes
are the most probable for altitudes ~ 1 ER. The auroral kilometric radiation
(AKR) at frequencies ~ 100 kHz is associated with these accelerated electrons.
The acceleration of electrons and AKR can be observed almost continuously
during the first minute and then from time to time with pauses about 35-40 s
till 6-8 min after the release. The betatron acceleration of electrons at the
recovery of the geomagnetic field is also discussed. This mechanism could be
responsible for the acceleration of electrons resulting in the aurorae and
ultra short radio wave storm at frequencies 50-300 MHz observed at the 8-10th
min after the release.Comment: Presented at COSPAR 200