Cross sections for (n, xn) reactions between 7.5 and 28 MeV

Abstract

A total of 236 cross sections for (n, xn) reactions have been measured at neutron energies between 7.5 and 28 MeV, using radiochemical techniques. Cross sections for (n, n ) and (n, 2n) reactions are reported on Ir193; (n, 2n) cross sections on Sc45 and Ni58; (n, 2n) and (n, 3n) cross sections on Y89, Zr90, and Ag107; (n, 2n), (n, 3n), and (n, 4n) cross sections on Tm169, Lu175, Ir191, Au197, and Tl203; (n, 3n) and (n, 4n) cross sections on Eu151; and (n, 4n) cross sections on Tl205. Neutron fluences were determined by either the Al27(n, ±)Na24 or the Zr90(n, 2n)Zr89 reactions appropriately combined with proton-recoil telescope measurements. The excitation functions are compared with calculations based on a model incorporating both compound-nucleus and preequilibrium decay modes. Cross sections for the Al27(n, ±)Na24 reaction between 21 and 26 MeV are also reported. NUCLEAR REACTIONS Al27(n, ±), E=21.4-4-26.0 MeV; Sc45(n, 2n), E=14.1-28.1 MeV; Ni58(n, 2n), E=16.2-28.1 MeV; Y89(n, 2n), (n, 3n), E=14.1-28.1 MeV; Ag107(n, 2n), (n, 3n), E=13.4-28.1 MeV; Eu151(n, 3n), (n, 4n) E=14.8-28.0 MeV; Tm169(n, 2n), (n, 3n), (n, 4n), E=8.6-28.0 MeV; Ir191(n, 2n), E=8.6-24.5 MeV; Ir191(n, 3n), (n, 4n), E=16.2-28.0 MeV; Ir193(n, n), E=7.6-14.7 MeV; Ir193(n, 2n), E=8.6-21.2 MeV; Au197(n, 2n), (n, 3n), (n, 4n), E=8.6-28.1 MeV; Ti203(n, 2n), (n, 3n), (n, 4n), E=8.6-28.0 MeV; Tl205(n, 4n), E=23.3-28.0 MeV; Zr(n, xn), E=14.1-28.1 MeV; Lu(n, xn), E=8.5-28.0 MeV; measured (E). Estimated Zr90(n, 2n), (n, 3n), Lu175(n, 2n), (n, 3n), (n, 4n), (E). Comparison with combined statistical and preequilibrium model. RADIOACTIVITY Ir189,190, Irm193; measured T12. © 1975 The American Physical Society.