Lead Slowing-Down Neutron Spectrometry 1: Cross-Section Data for ²⁴¹Am(n,f), ^242mAm(n,f), and ²⁴³Am(n,f) at Energies up to 100 keV

This paper is an overview of the results obtained by a collaborative team of researchers from the Institute for Nuclear Research, Russian Academy of Sciences (INR RAS), and State Scientific Center of the Russian Federation—Institute of Physics and Power Engineering (SSC RF—IPPE) using the SVZ-100 lead slowing-down neutron spectrometer. The study focuses on measuring the fission cross sections of americium isotopes ²⁴¹Am, ^242mAm, and ²⁴³Am when bombarded by neutrons with energies below 100 keV. The high efficiency of the SVZ-100, facilitated by its substantial working-substance mass (100 t of high-purity lead) and neutron generation through proton irradiation with a 209-MeV accelerator at the INR RAS, enables the investigation of neutron-nuclear processes in microgram samples of radioactive nuclides, which is unattainable in experiments using time-of-flight spectrometry. Unique scientific information is acquired through lead slowing-down neutron spectrometry by collaborative research efforts at the INR RAS and SSC RF—IPPE. This information partially fills gaps or complements existing but often contradictory or insufficient data from experiments conducted on both time-of-flight installations and lead slowing-down neutron spectrometers at other research centers. The results of collaboration of the INR RAS and SSC RF—IPPE are documented in international nuclear data repositories, indicating, in several instances, the need for adjustments to recommended approximating and calculated values. Information is given on some implemented and planned studies on neutron fission cross sections of americium isotopes at other centers following completion of the collaboration of the INR RAS and SSC RF—IPPE.