Gamma rays in L-B coordinates at CORONAS-I altitude
Kuznetsov, S. N.
Myagkova, I. N.
arxiv: Astrophysics::High Energy Astrophysical Phenomena | Physics::Space Physics
We present here observations of gamma rays in the energy range between
3.0 and 8.3 MeV gathered by the SONG instrument aboard low-altitude
polar-orbiting satellite CORONAS-I throughout the period March-June 1994.
We concentrate on the emissions related to the trapped particles and
organize CORONAS-I measurements in the magnetic <i>L–B</i> coordinate system.
The spatial distribution of the average gamma-ray counts reveals that the
most intense fluxes were observed under the inner radiation belt, at <i>L</i><2,
and that they are exclusively confined into the region of stably trapped
particles, where daughter gamma rays could result from the interactions
within the spacecraft and instrumental matter. In the outer radiation zone (<i>L</i>~4), the enhanced
gamma radiation, also detected outside the stably trapping region, shows
pronounced longitudinal variations. The observed eastward increase in
the gamma-ray count rate suggests quasi-traped energetic (megavolt) electrons
as a source of the gamma rays both in the upper atmosphere
and in the satellite matter, most likely, through the bremsstrahlung
process in the studied energy domain.<br><br>
<b>Keywords.</b> Magnetospheric physics (Energetic particles,
precipitating; Energetic particles, trapped; Magnetosphereionosphere