A new numerical model of particle propagation in the Galaxy has been developed, which allows the study of cosmic-ray and gamma-ray production and propagation in 2D or 3D, including a full reaction network. This is a further development of the code which has been used for studies of cosmic ray reacceleration, Galactic halo size, antiprotons and positrons in cosmic rays, the interpretation of dif...

We extend previous studies of mixed-composition extragalactic cosmic-ray source models, by investigating the influence of a non-negligible extragalactic magnetic field on the propagated cosmic-ray spectrum and composition. We study the transport of charged particles in turbulent fields and the transition from a ballistic to a diffusive propagation regime. We introduce a method allowing a fast i...

Neutrinos offer a particularly promising eye on the extreme Universe. Neutrinos are not attenuated by intervening radiation fields such as the Cosmic Microwave Background, and so they are messengers from the very distant and very young phase of the universe. Also, neutrinos are not deflected by cosmic magnetic fields, and so they should point to their sources. In addition, there are particle ph...

Model calculations of the particle flux on the surface of Mars due to the Galactic Cosmic Rays (GCR) can provide guidance on radiobiological research and shielding design studies in support of Mars exploration science objectives. Particle flux calculations for protons, helium ions, and heavy ions are reported for solar minimum and solar maximum conditions. These flux calculations include a desc...

I N THE last three years, progress ,in the understanding of the production of cosmic rays by the sun has been rapid. This is because the period of high solar activity provided a large variety of events to study and many new types of measurements were developed. At the present time we have data obtained on the solar cosmic rays at high altitude with nuclear emulsions both in balloons and in rock...

the dependence of the lateral distribution of cherenkov light in simulated extensive air showers to the energy and the mass of the primary cosmic rays has been studied. it has been shown that a previous claim about mass independent proportionality of shower energy to the total cherenkov photon number is not valid in energies below eeas ~ 1014 ev. we have found that the core distance of the so c...

In this paper we review the hypothesis that a substantial part of the cosmic ray ux observed above about 10 19 eV may be produced by decaying or annihilating topo-logical defects left over from phase transitions in the early universe at grand uniication energy scales (10 16 GeV). Possible signatures of cosmic ray producing defect models are discussed which could be tested experimentally in the ...

A surprisingly large concentration of radioactive Be was observed in the upper atmosphere at altitudes above 320 km on the LDEF satellite that was recovered in January 1990. We report on follow-up experiments on Russian spacecraft at altitudes of 167 to 370 km during the period of 1996 to 1999, specifically designed to measure Be concentrations in low earth orbit. Our data show a significant co...

Based on a conjecture about the diffusion tensor of relativistic particles perpendicular to the magnetic field at a shock, and considering particle drifts, I develop a theory to account for the Cosmic Ray spectrum between 10 GeV and 3 10 GeV. The essential assumption is that the free mean path perpendicular to the magnetic field is independent of energy and has the scale of the thickness of the...