Astrophysics of Galactic charged cosmic rays
  A review is given of the main properties of the charged component of galactic
cosmic rays, particles detected at Earth with an energy spanning from tens of
MeV up to about 10^19 eV. After a short introduction to the topic and an
historical overview, the properties of cosmic rays are discussed with respect
to different energy ranges. The origin and the propagation of nuclei in the
Galaxy are dealt with from a theoretical point of view. The mechanisms leading
to the acceleration of nuclei by supernova remnants and to their subsequent
diffusion through the inhomogeneities of the galactic magnetic field are
discussed and some clue is given on the predictions and observations of fluxes
of antimatter, both from astrophysical sources and from dark matter
annihilation in the galactic halo. The experimental techniques and
instrumentations employed for the detection of cosmic rays at Earth are
described. Direct methods are viable up to 10^14 eV, by means of experiments
flown on balloons or satellites, while above that energy, due to their very low
flux, cosmic rays can be studied only indirectly by exploiting the particle
cascades they produce in the atmosphere. The possible physical interpretation
of the peculiar features observed in the energy spectrum of galactic cosmic
rays, and in particular the so-called "knee" at about 4x10^15 eV, are
discussed. A section is devoted to the region between about 10^18 and 10^19 eV,
which is believed to host the transition between galactic and extragalactic
cosmic rays. The conclusion gives some perspectives on the cosmic ray
astrophysics field. Thanks to a wealth of different experiments, this research
area is living a very flourishing era. The activity is exciting both from the
theoretical and the instrumental sides, and its interconnection with astronomy,
astrophysics and particle physics experiences non-stop growth.
