Cosmic Rays propagation in the Heliosphere
The cosmic rays modulation inside the heliosphere is well described by a transport equation introduced by Parker in 1958. We used the HelMed Monte Carlo code to reproduce the modulation effect in the inner heliosphere depending from solar activity and solar polarity. In this 2-D MonteCarlo approach we include a general treatment of the diffusion tensor that compound an enhancement of perpendicular diffusion coefficient at high solar latitude and a polar increased magnetic field. In our simulation we considered a heliosphere that changes the modulation parameter with the distance from the Earth, including periods prior to the one we intend to simulate. In this work we furthermore exploited the energy distribution of injected particles to the observed flux. We compared HelMed results with data of BESS-97, AMS-98, BESS-98, BESS-99, BESS-2000, BESS-2002 and PAMELA; this covering a period of 11 years and two solar polarity, these simulations are well in agreement with experimental data.
