HR: 0800h
AN: SH51C-02    [Abstracts]
TI: Radiation Belts of Antiparticles in Planetary Magnetospheres
AU: Pugacheva, G I
EM: galinasm@pochta.ru
AF: Space Research Institute of Russian Academy of Science, Department 51, Profsoyuznaya 84/32, Moscow, 117997, Russian Federation
AU: * Gusev, A A
EM: ganso@pochta.ru
AF: Space Research Institute of Russian Academy of Science, Department 51, Profsoyuznaya 84/32, Moscow, 117997, Russian Federation
AU: Jayanthi, U B
EM: jayanthi@das.inpe.br
AF: National Institute for Space Research, INPE, São Jose dos Campos, SP, Brazil
AU: Martin, I M
EM: martin@ita.br
AF: University of Taubate - UNITAU, Taubate, Brazil
AU: Spjeldvik, W N
EM: WSpjeldvik@weber.edu
AF: Weber State University, Department of Physics, Ogden, Utah, United States
AB: The Earth's radiation belts could be populated, besides with electrons and protons, also by antiparticles, such as positrons (Basilova et al., 1982) and antiprotons (pbar). Positrons are born in the decay of pions that are directly produced in nuclear reactions of trapped relativistic inner zone protons with the residual atmosphere at altitudes in the range of about 500 to 3000 km over the Earth's surface. Antiprotons are born by high energy (E > 6 GeV) cosmic rays in p+p - p+p+p+ pbar and in p+p - p+p+n+nbar reactions. The trapping and storage of these charged anti-particles in the magnetosphere result in radiation belts similar to the classical Van Allen belts of protons and electrons. We describe the mathematical techniques used for numerical simulation of the trapped positron and antiproton belt fluxes. The pion and antiproton yields were simulated on the basis of the Russian nuclear reaction computer code MSDM, a Multy Stage Dynamical Model, Monte Carlo code, (i.e., Dementyev and Sobolevsky, 1999). For estimates of positron flux there we have accounted for ionisation, bremsstrahlung, and synchrotron energy losses. The resulting numerical estimates show that the positron flux with energy >100 MeV trapped into the radiation belt at L=1.2 is of the order ~1000 m-2 s-1 sr-1, and that it is very sensitive to the shape of the trapped proton spectrum. This confined positron flux is found to be greater than that albedo, not trapped, mixed electron/positron flux of about 50 m-2 s-1 sr-1 produced by CR in the same region at the top of the geomagnetic field line at L=1.2. As we show in report, this albedo flux also consists mostly of positrons. The trapped antiproton fluxes produced by CR in the Earth's upper rarified atmosphere were calculated in the energy range from 10 MeV to several GeV. In the simulations we included a mathematic consideration of the radial diffusion process, both an inner and an outer antiproton source, losses of particles due to ionization process, annihilation, and nuclear interactions with the ambient matter. We have found that the Earth's antiproton belt possesses about 6-60 times larger antiproton fluxes compared to the galactic fluxes in interplanetary space during minimum and maximum solar activity at all energies in confinement zone. The radiation belt antiproton fluxes are spread into a wider L-shell range than its generation location around L=1.2. This is due to diffusion processes, and it demonstrates that radial diffusion as a relatively significant process for antimatter, even in the inner magnetosphere. Antimatter accumulated in the magnetospheres of solar system bodies may be of significance for space travel. It could be used as a propulsion for space missions to the outer planets and beyond. Antimatter has an energy density more than ten orders of magnitude higher than the best chemical propellants currently used in rocket systems. References: Basilova, R. N., A.A. Gusev, G.I. Pugacheva , Geom. and Aeronom. V. 22, p. 671-673, 1982.Chen, J., T. Dementyev, A.V., Sobolevsky, N.M. Radiation Measurements, 30, 553, 1999.
DE: 2104 Cosmic rays
DE: 2114 Energetic particles (7514)
DE: 2134 Interplanetary magnetic fields
DE: 2720 Energetic particles: trapped
DE: 7807 Charged particle motion and acceleration
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Joint Assembly