Neutron Production by Heavy-Ion Bombardments

Neutron yields from C¹², N¹⁴, and Ne²⁰ bombardments of a number of target elements have been measured by an activation method. The maximum bombarding energies were 10.4 Mev per nucleon of the incident ion. Neutron yields have been calculated by assuming complete fusion of the two nuclei, with an interaction radius of r₀≈1.5×10^-13 cm, followed by de-excitation of the compound nuclei by neutron emission only. Calculated neutron yields are a factor of about two higher than experiment in the case of heavy target nuclei, with greater differences for light targets. Some possible refinements of the theory that could bring the results closer to agreement with experiment are mentioned.