  Cosmic rays of kinetic energies below ~1 GeV per nucleon are thought to play
a key role in the chemistry and dynamics of the interstellar medium. They are
also thought to be responsible for nucleosynthesis of the light elements Li,
Be, and B. However, very little is known about the flux and composition of
low-energy cosmic rays since the solar modulation effect makes impossible a
direct detection of these particles near Earth. We first discuss the
information that the light elements have brought to cosmic-ray studies. We then
discuss the prospects for detection of nuclear gamma-ray line emission produced
by interaction of low-energy cosmic rays with interstellar nuclei.
