Related papers: Composition of Primary Cosmic Rays Beyond the ``Kn…
The most recent experimental results on the cosmic ray composition and energy spectrum above 1 TeV are reviewed and discussed. All data agree on the presence of the so-called ``knee'' at an energy E(knee) = 3-4 PeV; the knee is seen in all…
Primary energy spectrum of cosmic rays exhibits a knee at about $3$ PeV where a change in the spectral index occurs. Despite many efforts the origin of such a feature of the spectrum is not satisfactorily solved yet. Here it is proposed…
The possibility of estimating the mass composition of primary cosmic rays above the knee of its energy spectrum through the study of high energy gamma rays, muons and neutrinos produced in the interactions of cosmic rays with the solar…
The cosmic ray primary composition in the energy range between 10**15 and 10**16 eV, i.e., around the "knee" of the primary spectrum, has been studied through the combined measurements of the EAS-TOP air shower array (2005 m a.s.l., 10**5…
The small change in the spectral slope of the overall intensity of cosmic rays near 1 PeV may be associated with the endpoint energy of supernova shock acceleration. A crucial test of this connection and other ideas of the origin of the…
Interpretation of the energy spectrum and arrival distribution of cosmic rays is complicated by lack of knowledge of the nature of the primaries. We review claims for the mass composition above 1017 eV where it can be determined only…
Primary cosmic ray particles above energies of about 100 TeV are investigated by large-area ground based detector installations, observing various components of the development of extensive air-showers (EAS). By such an indirect access to…
A brief review about the chemical composition of cosmic rays in the energy range 10^15 < E < 10^20 eV is given. While there is convincing evidence for an increasingly heavier composition above the knee, no clear picture has emerged at the…
The main purpose of this work is to find the causes of the break of the cosmic ray spectrum at an energy of 3 PeV, which is called the knee. The solution of the problem is associated with the determination of the nuclear composition of…
Project GRAND presents results on the atomic composition of primary cosmic rays. This is accomplished by determining the average height of primary particles that cause extensive air showers detected by Project GRAND. Particles with a larger…
Energetic particles, traditionally called Cosmic Rays, were discovered nearly a hundred years ago, and their origin is still uncertain. Their main constituents are the normal nuclei as in the standard cosmic abundances of matter, with some…
Recent progress in cosmic ray physics covering the energy range from about 10^{14} eV to 10^{19} eV is reviewed. The most prominent features of the energy spectrum are the so called `knee' at E ~ 3 * 10^{15} eV and the `ankle' at few…
All information about primary cosmic rays above the knee has been obtained from results of EAS investigations. At that, two alternative approaches exist: cosmophysical and nuclear physical. In the frame of the first one, all changes in…
In this work we examine with the help of Monte Carlo simulation whether a consistent primary energy spectrum of cosmic rays emerges from both the experimentally observed total charged particles and muon size spectra of cosmic ray extensive…
The determination of the primary cosmic ray mass composition from the characteristics of extensive air showers (EAS), obtained at an observation level in the lower half of the atmosphere, is still an open problem. In this work we propose a…
Our study exploits the Constant Intensity Cut principles applied simultaneously to muonic and electromagnetic detectors of cosmic rays. We use the fact that the ordering of events according to their signal sizes induced in different types…
Cosmic rays around the knee are generally believed to be of galactic origin. Observations on their energy spectrum and chemical composition are important for understanding the acceleration and propagation of these cosmic rays. In addition,…
Monte Carlo simulations show that the pulse profile of Cherenkov photons measured near the core of an extensive air shower is sensitive to the secondary muon/electron ratio of the cascade. Cherenkov pulses can easily be measured with a…
We report the analysis of the Ne-Nmuon coincident events collected by the MACRO/EAS-TOP collaboration at the Gran Sasso Laboratories. The result points to a primary composition becoming heavier around the knee of the primary spectrum (in…
The origin of the knee in the energy spectrum of cosmic rays is an outstanding problem in astroparticle physics. Numerous mechanisms have been proposed to explain the structure in the all-particle spectrum. In the article basic ideas of…