Features of the absorption of 2-to 40-TeV cosmic-ray hadrons in lead

On absorption of the hadron component of EAS cores in a large lead calorimeter at ‘knee’-range energies

“…On the other hand, the EAS with a measured hadron energy of about 30 TeV are produced by primary particles with energy around 1 PeV [8] which is close to the knee energy region. If the composition and spectra of EAS core particles are changed then one can expect the change in the absorption length in lead, as was shown in [9]. In this paper we answer to the question: 'Can the changes in the PCR composition lead to a weak absorption of EAS core particles in lead?…”

“…Individual ionization curves for slow attenuating cores fluctuate very strongly and very often the maximal ionization is deposited at the end of the ionization curves. Some events resemble cascades originated by high-energy muons [18].…”

“…The bremsstrahlung process dominates at u > 0.1, while at u < 0.1 the probability of pair production exceeds bremsstrahlung by several orders of magnitude. We have calculated [18] the spectrum of cascades, I cas (E cas ), initiated in lead by muons with power-law spectra with different exponents: γ = −3.7 (usual muons), γ = −2.7 (prompt muons) and γ = −1.7-2.0 (for muons with flat spectra). The coefficient of transition from the muon spectrum to the spectrum of cascades with the same energy was calculated:…”

“…So two years ago we started this work with an analysis of absorption of single (without accompanying EAS) hadrons with energies 2-40 TeV detected in the BIC. The simulation of protons passing through the BIC was done taking proper account of the complex calorimeter structure, processes of particle detection with ionization chambers, and cascade selection criteria for the first time ever [9]. The simulation version involving the GEANT 3.21+FLUKA generator describes averaged experimental cascades very well at energies up to 10 TeV.…”