Effective reaction cross-sections for 7Be production by interaction of fast neutrons in an accelerator-driven system with light nuclei

The measurement of effective reaction cross-sections for 74Be production by irradiation of light nuclei (C, O, F, Na, Cl, K) with fast neutrons from the interaction of 660 MeV protons with a thick lead target is described. The experiment was conducted on the proton accelerator at the Nuclear Problems Laboratory (JINR, Dubna). Measurements of the neutron flux density and the 74Be production rate were performed using the activation method. Cross-sections of 74Be production decrease from 0.01 barns for carbon to 0.00005 barns for potassium. The model of nuclear reactions of ∼20-50 MeV neutrons with light nuclei taking into account the effective potential barrier for 74Be was used. In general, the model correctly reproduces the measured values. (author)