Anti-particles in the inner magnetosphere: energetic positron population

Abstract

Anti-particles can be generated as secondaries by nuclear reactions of cosmic rays and energetic trapped particles with the residual terrestrial atmosphere, and can oe trapped in the magnetosphere by the Earth's magnetic field. The trapped fluxes of anti-protons and positrons could be larger than the interstellar fluxes generated by cosmic rays. The possible existence of a natural positron belt in the Earth's magnetosphere is considered. It is suggested that the positrons may be produced by the nuclear reaction of trapped relativistic protons in the inner zone with the residual atmosphere. The positron spectrum in the range of 10 - 100 MeV at the top of L = 1.2 is calculated and found to be in agreement with experimental results.