Neutron production in (α, n) reactions

摘要

Neutrons can induce background events in underground experiments looking for rare processes. Neutrons in a MeV range are produced in radioactive decays via spontaneous fission and (α, n) reactions, and by cosmic rays. Neutron fluxes from radioactivity dominate at large depths (＞ 1 km w. e.). A number of computer codes are available to calculate cross-sections of (or, n) reactions, excitation functions and neutron yields. We have used EMPIRE2.19/3.2.3 and TALYS1.9 to calculate neutron production cross-sections and branching ratios for transitions to the ground and excited states, and modified SOURCES4A to evaluate neutron yields and spectra in different materials relevant to high-sensitivity underground experiments. We report here a comparison of different models and codes with experimental data, to estimate the accuracy of these calculations.