  A comparative theoretical study of the damages produced by protons and pions,
in the energy range 50 MeV - 50 GeV, in diamond, is presented. The
concentration of primary defects (CPD) induced by hadron irradiation is used to
describe material degradation. The CPD has very different behaviours for
protons and pions: the proton degradation is important at low energies and is
higher than the pion one in the whole energy range investigated, with the
exception of the Delta33 resonance region, where a large maximum of the
degradation exists for pions. In comparison with silicon, the most investigated
and the most studied material for detectors, diamond theoretically proves to be
one order of magnitude more resistant, both to proton and pion irradiation.
