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Our backtracing code (Geomagsphere), for Cosmic Rays trajectory reconstruction in the Earth Magnetosphere, has been developed using the latest models of Internal (IGRF-11) and External (Tsyganenko 1996 and 2005) field components. Backtracing technique was applied to AMS-02 data to separate Primary Cosmic Rays Particles from Secondary particles. We tested the accuracy of Magnetic Field models (with and without the external field component) comparing them with data from satellite (GOES, 1998 and CLUSTER, 2004). In both periods TS05 reproduces the magnetic field strength with good accuracy. Moreover the specificity of the TS05 model, designed for solar storms, was tested comparing it with data taken by CLUSTER during the last solar active period (from 2011 to 2013). We found a relevant difference on the fraction of AMS-02 cosmic rays identified as trapped and secondary particles, especially during solar flare periods (i.e. those occurred in March and May 2012). Finally the backtracing of a wide sample, more than 70 days, of AMS-02 proton data was used to get the real geomagnetic cutoff. We found an increased counting rate of primary particles at high latitudes with respect to the IGRF model. Besides we built a procedure to extract from data the rate of secondary particles.

The precise measurements of the electron plus positron spectra, in the energy range from 0.5 GeV up to 1 TeV, were published by the AMS-02 collaboration. We focus the attention above 10 GeV where the solar modulation effects are negligible. The differences between these data and the 'classical' Local Interstellar Spectra, obtained using optimized GALPROP parameters, show an extra contribution suggesting an equal amount for both electrons and positrons. Thus, they would be generated by a pair production process from the same source. We studied the contribution from PulsarWind Nebulae starting from the photon spectrum (due to synchrotron and inverse Compton processes) detected by gamma-ray telescopes. A diffusion model is applied from the source up to the Solar System and the propagated spectra are compared with the AMS-02 data. Above 100 GeV, Vela-X is the main candidate to contribute to the observed excess, while, below 100 GeV, more aged pulsars like Monogem give a higher contribution. An estimation on the degree of anisotropy from these sources is also presented.

The cosmic rays modulation inside the heliosphere is well described by a transport equation introduced by Parker in 1965. To solve this equation several approaches were followed in the past. Recently the Monte Carlo approach becomes widely used in force of his advantages with respect to other numerical methods. In the Monte Carlo approach, the transport equation is associated to a fully equivalent set of Stochastic Differential Equations. This set is used to describe the stochastic path of a quasi-particle from a source, e.g., the interstellar medium, to a specific target, e.g., a detector at Earth. In this work, we present both the Forward-in-Time and Backward-in-Time Monte Carlo solutions. We present an implementation of both algorithms in the framework of HelMod Code showing that the difference between the two approach is below 5% that can be quoted as the systematic uncertain of the Method itself.

In this contribution we present the calculation of a realistic time dependent geomagnetic cutoff along the International Space Station orbit, at about 400 km above the Earth's surface with an inclination of 51.6o. For this work, based on the analysis of data collected by the AMS02 experiment during the first year of operation, the Tsyganenko 05 and IGRF models have been employed, including the temporal variation of the external component of the geomagnetic field due to the solar activity. The evaluation of the cutoff has been performed every 30 seconds along the ISS orbit by means of a back-tracing technique of 1500 random trajectories simulated in the field of view of the AMS-02 experiment at any given ISS location. The technique and its results will be discussed, as well as the relevance of this study to distinguish galactic cosmic rays from trapped secondary components in the geomagnetic field.