CERN homepage INFN homepage
FLUKA: 16.1.2} The High Energy All-Nucleon Spectrum Previous Index Next

16.1.2} The High Energy All-Nucleon Spectrum


 The All-Nucleon Spectrum is obtained modifying the fit of the All-Nucleon flux
 proposed by the Bartol group [Agr96], using the All-Particle Spectrum (16.1.1})
 up to 100 GeV and data published in ICRC 2003. Fluxes are read from a file
 named "allnucok.dat" giving the total energy (GeV), the fluxes (E.dN/dE)
 and the neutron/proton ratios. This option ("All Nucleon Flux") is chosen with
 command SPECSOUR and 
SDUM
= GCR-ALLF (see details in 16.7}). The user can decide whether to sample neutrons and protons from the file and to transport them using the superposition model, or to consider all neutrons as being bound in alpha particles and to transport protons and alphas. This latter choice has the advantage of taking better into account the magnetic field, which has no effect on the neutrons. For the proton component at energies larger than 100 GeV, using the normalization obtained at 100 GeV, a spectral index gamma = -2.71 is assumed. A spectral index gamma = -3.11 is assumed above the knee at 3000 TeV. For what concerns the He component, gamma = -2.59 is used above 100 GeV and a charge-dependent knee is assumed according to the rule: E_nucleon = Z * 3000 TeV/A. Higher Z components have been grouped in CNO, MgSi and Fe sets and treated using an All-Particle spectrum with the above mentioned charge-dependent knee parameterisation.

Previous Index Next