MINERVINI, GABRIELEGABRIELEMINERVINILOTTI, SimoneSimoneLOTTIMACCULI, CLAUDIOCLAUDIOMACCULI2024-06-242024-06-242019http://hdl.handle.net/20.500.12386/35228The main aim of this technical note is to consolidate the absolute level of the Galactic Cosmic Ray (GCR) protons spectrum in L2 and its uncertainty during the ATHENA mission lifetime (2031-2034), being protons the dominant contribution in background studies. For this purpose data from the Voyager2, SOHO and PAMELA spacecraft and neutron monitor (NM) measurements have been analyzed and compared also with the CREME96 and CREME2009 models, to obtain the most conservative estimate of the GCR protons spectrum. For sake of completeness also the alpha and electrons spectra will be reported. A solar cycle consists of 11 years period between two subsequent minima of the solar activity. Two subsequent solar cycles are characterized by opposite polarities of the solar magnetic field, and together they make a complete helio-magnetic cycle (22 years). These two polarities of the solar magnetic field will be indicated with “A>0”(positive polarity of the northern emisphere) and “A<0”. The solar magnetic field modulation strongly influences the GCR fluxes at 1 AU: the stronger the solar magnetic field, the higher the shielding from cosmic rays. As a consequence, the highest level of GCR is expected during solar minima. In Section 2 we will review the current GCR models, comparing them to available experimental datasets in order to verify their reliability. In the following sections we will develop a new GCR model based on the highest ever measured GCR flux: in Section 3 we will identify the highest case ever registered, thanks to the wide time coverage provided by the Neutron Monitors stations (from early sixties up to today); in Section 4 we will analyze in depth the experimental data for this case to develop a new, more conservative, GCR protons model. Finally, in Section 6, we will analyze the expected GCR protons variability during the mission lifetime.ELETTRONICOenResearch reportFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation