Features of the Mechanism of Formation of the Radiation Belt of High-Energy Electrons and Positrons

• Published in: Physics of atomic nuclei Vol. 81; no. 4; pp. 520 - 525
• Main Authors: Mikhailovа, Yu. V., Galper, A. M., Mikhailov, V. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-07-2018; Springer; Springer Nature B.V
• Subjects: ALTITUDE; Analysis; Atmospheric models; ATOMIC AND MOLECULAR PHYSICS; ATOMS; DENSITY; Earth magnetosphere; Electrons; Elementary Particles and Fields; ENERGY LOSSES; Fluxes; Geomagnetic fields; Inner radiation belt; Magnetosphere; MEV RANGE 10-100; Particle and Nuclear Physics; Particle physics; Particle trajectories; PARTICLES; Physics; Physics and Astronomy; POSITRONS; Radiation (Physics); RADIATION BELTS; Reduction; TRAJECTORIES; TRAPPED ELECTRONS; Trapped particles; TRAPPING
• ISSN: 1063-7788; 1562-692X
• DOI: 10.1134/S1063778818040130

New results of the PAMELA experiment revealed significant difference in the electron and positrons flux and fraction between trapped particles of the radiation belt and quasitrapped particles. A decrease in the ratio of the electron-to-positron fluxes both with increasing altitude and with decreasing energy was observed for the inner radiation belt, but this does not fit in currently used models. The residual atmosphere density in the trapping region for
L
~ 1.15−1.2 is estimated on the basis of calculations of trapped-particle trajectories in the Earth’s magnetosphere. It is shown that processes leading to the energy loss for trapped electrons and positrons in the interactions with residual-atmosphere atoms play an important role in the formation of fluxes of these particles, but these processes cannot cause the reduction of the positron fraction in the total flux at energies below some 100 MeV. The role of the process of δ-electron production in the formation of the belt of trapped electrons and positrons is considered. Allowance for this process makes it possible to explain the above reduction at least partly.