  The main signature of the interaction between cosmic rays and molecular
clouds is the high ionisation degree. This decreases towards the densest parts
of a cloud, where star formation is expected, because of energy losses and
magnetic effects. However recent observations hint to high levels of ionisation
in protostellar systems, therefore leading to an apparent contradiction that
could be explained by the presence of energetic particles accelerated within
young protostars. Our modelling consists of a set of conditions that has to be
satisfied in order to have an efficient particle acceleration through the
diffusive shock acceleration mechanism. We find that jet shocks can be strong
accelerators of protons which can be boosted up to relativistic energies.
Another possibly efficient acceleration site is located at protostellar
surfaces, where shocks caused by impacting material during the collapse phase
are strong enough to accelerate protons. Our results demonstrate the
possibility of accelerating particles during the early phase of a
proto-Solar-like system and can be used as an argument to support available
observations. The existence of an internal source of energetic particles can
have a strong and unforeseen impact on the star and planet formation process as
well as on the formation of pre-biotic molecules.
