Detecting gamma-rays from discrete astronomical objects offers the potential to directly study sites of cosmic particle acceleration. Alternatively, the pervasive diffuse gamma-ray emission component caused by interactions of cosmic rays with interstellar gas and radiation fields carries information about the spatial distribution of cosmic particle accelerators and reveals details about the cha...

EGRET data on the Gamma ray emission from the inner Galaxy have shown a rather flat spectrum. This spectrum extends to about 50 GeV in photon energy. It is usually assumed that these gamma-rays arise from the interactions of cosmic ray nuclei with ambient matter. Cosmic Ray particles have been observed up to 3 10 20 eV, with many arguments suggesting, that up to about 3 10 18 eV they are of Gal...

Diffuse interstellar clouds show large abundances of H3 which can be maintained only by a high ionization rate of H2. Cosmic rays are the dominant ionization mechanism in this environment, so the large ionization rate implies a high cosmic-ray flux, and a large amount of energy residing in cosmic rays. In this paper we find that the standard propagated cosmic-ray spectrum predicts an ionization...

We report high-resolution observations made in interplanetary space of 83-284 MeV per nucleon galactic cosmic-ray iron isotopes and directly establish that 56Fe is the dominant cosmic-ray Fe isotope. We find the following percentage abundances for Fe at the cosmic-ray source: 54Fe = 9(+8, -5)%, 55Fe:::; 7%, 56Fe = 91(+5, -11)%, 57Fe:::; 8%, and 58Fe:::; 6%. When compared to calculated nucleosyn...

Contribution of nearby pulsars to the cosmic rays observed at Earth has been studied. It is found that the experimental bound on amplitude of cosmic ray anisotropy may produce significant constraint on the efficiency of converting pulsar rotational energy to emitted particles kinetic energy. Cosmic ray fluxes from two well known nearby gamma ray pulsars, namely the Vela and Geminga pulsars, are...

EGRET data on the Gamma ray emission from the inner Galaxy have shown a rather flat spectrum. This spectrum extends to about 50 GeV in photon energy. It is usually assumed that these gamma-rays arise from the interactions of cosmic ray nuclei with ambient matter. Cosmic Ray particles have been observed up to 3 10 20 eV, with many arguments suggesting, that up to about 3 10 18 eV they are of Gal...

Cosmic ray particles with energies in excess of 10 eV have been detected. The sources as well as the physical mechanism(s) responsible for endowing cosmic ray particles with such enormous energies are unknown. This report gives a review of the physics and astrophysics associated with the questions of origin and propagation of these EHE cosmic rays in the Universe. After a brief review of the ob...

  Deviation angles of secondary electrons and muons in simulated extensive air showers were studied. The angles have wide distribution, whose width depends on energy cuts imposed on shower particles. In this work, variation of deviation angles with the energy of secondary particles, shower energy, primary direction, and core distance was investigated. The results put limitations on application ...

The isotopes of lithium, beryllium, and boron (LiBeB) are known in nature to be produced primarily by CNO spallation and a a fusion from interactions between cosmic rays and interstellar nuclei. While the dominant source of LiBeB isotopes in the present epoch is cosmic-ray interactions, other sources are known to exist, including the production of Li from big bang nucleosynthesis. Precise obser...

Observations of cosmic-ray helium energy spectra provide important constraints on cosmic ray origin and propagation. However, helium intensities measured at Earth are affected by solar modulation, especially below several GeV/nucleon. Observations of helium intensities over a solar cycle are important for understanding how solar modulation affects galactic cosmic ray intensities and for separat...