Lead slowing-down neutron spectrometry 1: cross-section data for ²⁴¹Am(n, f), ^242mAm(n, f), ²⁴³Am(n, f) at energies up to 100 keV

Abstract

A review of the results of a series of works performed by a joint group of researchers from the INR RAS and the SSC RF–IPPE on the lead slowing-down neutron spectrometer SVZ-100 to measure the fission cross-sections of americium isotopes 241Am, 242mAm, 243Am by neutrons with energies below 100 keV is presented. Due to the large mass of the working substance (100 tons of high-purity lead) and the generation of neutrons by protons with an energy of 209 MeV at the INR RAS accelerator, the high aperture ratio of the SVZ-100 made it possible to study neutron-nuclear processes in microgram samples of radioactive nuclides, which is not available in experiments using time-of-flight spectrometry. Unique scientific information has been obtained, partially compensating for the missing, or supplementing the existing, but often contradictory or insufficient data of experiments performed both on time-of-flight facilities and on lead slowing-down neutron spectrometers at other research centres. The results of the work of INR RAS–SSC RF–IPPE are reflected in international nuclear databases and indicate in a number of cases the need to adjust the recommended approximating and calculated values. Information is provided on the few carried out experiments and planned studies of neutron-induced fission cross-sections of americium isotopes in other centres after the completion of the work of the INR RAS–SSC RF–IPPE.