Measurement of the cosmic ray hadron spectrum up to 30 TeV at mountain altitude: the primary proton spectrum

• Published in: Astroparticle physics 2003-06, Vol.19 (3), p.329-338
• Main Authors: Aglietta, M., Alessandro, B., Antonioli, P., Arneodo, F., Bergamasco, L., Bertaina, M., Castagnoli, C., Castellina, A., Chiavassa, A., Cini Castagnoli, G., D’Ettorre Piazzoli, B., Di Sciascio, G., Fulgione, W., Galeotti, P., Ghia, P.L., Iacovacci, M., Mannocchi, G., Morello, C., Navarra, G., Riccati, L., Saavedra, O., Trinchero, G.C., Valchierotti, S., Vallania, P., Vernetto, S., Vigorito, C.
• Format: Article
• Language: English
• Subjects: Cosmic rays; Hadrons; High energy calorimetry; Primary protons
• ISSN: 0927-6505; 1873-2852
• DOI: 10.1016/S0927-6505(03)00103-8

The flux of cosmic ray hadrons at the atmospheric depth of 820 g cm −2 has been measured by means of the EAS-TOP hadron calorimeter (Campo Imperatore, National Gran Sasso Laboratories, 2005 m a.s.l.). The hadron spectrum is well described by a single power law: S h (E h )=(2.25±0.21±0.34 sys )×10 −7 E h 1000 (−2.79±0.05) m −2 s −1 sr −1 GeV −1 overthe energy range 30 GeV–30 TeV. The procedure and the accuracy of the measurement are discussed. The primary proton spectrum is derived from the data by using the CORSIKA/QGSJET code to compute the local hadron flux as a function of the primary proton spectrum and to calculate and subtract the heavy nuclei contribution (basing on direct measurements). Over a wide energy range E 0=0.5–50 TeV its best fit is given by a single power law: S(E 0)=(9.8±1.1±1.6 sys )×10 −5 E 0 1000 (−2.80±0.06) m −2 s −1 sr −1 GeV −1 The validity of the CORSIKA/QGSJET code for such application has been checked using the EAS-TOP and KASCADE experimental data by reproducing the ratio of the measured hadron fluxes at the two experimental depths (820 and 1030 g cm −2 respectively) at better than 10% in the considered energy range.