Neutron production and energy generation by energetic projectiles: protons or deuterons?

A revival of interest for production of neutrons by light energetic projectiles has been arisen recently by the advent of new projects in nuclear technology such as accelerator-driven nuclear reactors, nuclear waste transmutation and the use of radioactive beams. In this context we try to estimate which of the light incident particles, namely protons or deuterons, are more favourable for neutron production. The problem is investigated by varying the incident energy of these projectiles for different target materials and assemblies. The averaged multiplicities, angular and energy distributions of neutrons produced are estimated and compared using the simplest target geometry. In addition, the energy gain factor, i.e. the ratio of the energy produced in the sub-critical target-fuel assembly to the one delivered by the beam, is presented for both of the incident particles as a function of their kinetic energy. It is shown that at lower energies (<600 MeV), the combination of deuteron beam with light metal target is the most efficient solution for energy generation, whereas at higher energies (>1 GeV) the difference between various combinations becomes less significant.