Cosmic Rays Propagation with HelMod: Difference between forward-in-time and backward-in-time approaches
S. Della Torre ; P. Bobik ; M. J. Boschini ; et al. ; - ASI Sponsor
Apr - 2016

Event Title : The 34th International Cosmic Ray Conference, 30 July- 6 August, 2015 The Hague, The Netherlands
Published in: PoS(ICRC2015)501
type: Conference Proceedings

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.

keywords :

Notes : This work is supported by Agenzia Spaziale Italiana under contract ASI-INFN I/002/13/0,Progetto AMS-Missione scientifica ed analisi dati.