Excitation of isomeric states in (n,n') reactions

The present status of our knowledge on activation cross-sections for metastable nuclear states by (n,n') reactions is reviewed and summarized. Though the emphasis is given to the cross-sections for 14 MeV neutrons, the neutron dependence of these cross-sections is also discussed briefly. Both the status of experimental data and the possibilities of theoretical calculations of (n,n') cross-sections are addressed and a new systematic of (n,n') cross-sections for isomer production at En ∼ 14 MeV is presented. Some striking discrepancies between the existing measurements and theoretical expectations are identified and possibilities for improved measurements are discussed. (author). 42 refs, 4 figs, 3 tabs