The 7Li(P,N)7 Be Reaction as a Source of Fast Neutrons for Smaller Compact Cyclotrons

The usefulness of the 7Li(p,n)7Be reaction as a fast neutron source for applications, such as neutron therapy etc., using smaller compact cyclotrons (proton energies of up to 15-18 MeV) has been investigated by measuring thin and thick target neutron spectra, absolute cross sections and angular distributions of various neutron groups produced in this reaction at 10.45 MeV. Our results indicate that the forward direction is still the preferred one for obtaining the most suitable fast neutron beam for biomedical application, and that moderately thick, rather than infinitely thick, target would provide higher mean energy. Moreover, it has also been shown that the 7Li(p,n)7 Be reaction is more suited for producing neutron beams for therapy than proton and deuteron induced reactions on Be at corresponding energies, and that a therapeutically useful neutron beam can be produced even with smaller compact cyclotrons.